Učinak temperature i dodatka indija na mehanička svojstva legure Al–0.21wt%Au

Tensile characteristics of both Al–0.21wt%Au and Al–0.21wt%Au–0.21wt%In alloys were investigated in the temperature range 493 K to 553 K. The coefficient of work hardening, χ = ∂σ2/∂², yield stress, σy, and fracture stress, σf , decreased with increasing deformation temperature (T) and exhibited abrupt increase at about 523 K. On the other hand, the fracture strain, ²f , and dislocation slip distance, L, increased with increasing deformation temperature and exhibited minima at about 523 K. The activation energy was determined in the range around 523 K to clarify the observed change in the behaviour of the hardening characteristics of the investigated samples.Istraživali smo istezna svojstva legura Al–0.21wt%Au i Al–0.21wt%Au–0.21wt%In na temperaturama 493 K do 553 K. Koeficijent mehaničkog očvršćivanja, χ = ∂σ2/∂², granica elastičnosti, σy, i granica loma, σf , smanjuju se pri povišenim temperaturama istezanja (T) te pokazuju nagao porast na oko 523 K. Nasuprot tome, lomno istezanje, ²f , i prosječna duljina klizanja dislokacija, L, povećali su se s povišenom temperaturom istezanja, a pokazuju i minimum na oko 523 K. Radi objašnjenja opaženih promjena u procesu očvršćivanja ispitivanih uzoraka odredili smo aktivacijsku energiju na temperaturama oko 523 K

Učinak temperature i dodatka indija na mehanička svojstva legure Al–0.21wt%Au

Tensile characteristics of both Al–0.21wt%Au and Al–0.21wt%Au–0.21wt%In alloys were investigated in the temperature range 493 K to 553 K. The coefficient of work hardening, χ = ∂σ2/∂², yield stress, σy, and fracture stress, σf , decreased with increasing deformation temperature (T) and exhibited abrupt increase at about 523 K. On the other hand, the fracture strain, ²f , and dislocation slip distance, L, increased with increasing deformation temperature and exhibited minima at about 523 K. The activation energy was determined in the range around 523 K to clarify the observed change in the behaviour of the hardening characteristics of the investigated samples.Istraživali smo istezna svojstva legura Al–0.21wt%Au i Al–0.21wt%Au–0.21wt%In na temperaturama 493 K do 553 K. Koeficijent mehaničkog očvršćivanja, χ = ∂σ2/∂², granica elastičnosti, σy, i granica loma, σf , smanjuju se pri povišenim temperaturama istezanja (T) te pokazuju nagao porast na oko 523 K. Nasuprot tome, lomno istezanje, ²f , i prosječna duljina klizanja dislokacija, L, povećali su se s povišenom temperaturom istezanja, a pokazuju i minimum na oko 523 K. Radi objašnjenja opaženih promjena u procesu očvršćivanja ispitivanih uzoraka odredili smo aktivacijsku energiju na temperaturama oko 523 K

Cooling Rate and Fibrous Type Striated Deformations Effects on the Mechanical Properties of Sn 8.6 wt. % Zn Alloy

Sn-Zn alloy has been taken as one of the most important lead free solder alloys due to the toxicity and the alpha radiation of lead impurities. The influence of cooling rate on the mechanical and structural properties of Sn ndash 8.6 wt. % Zn lead free solder alloy was studied.nbsp The microstructure of the quenched and slowly cooled samples of Sn ndash Zn alloy was examined by X ndash rays analysis and Scanning electron microscopy (SEM). There is an appearance of fibrous type striated deformations on the surfaces of the quenched samples more than those on the surfaces of the slowly cooled samples. The hardening parameters were obtained through stress-strain relations in the temperature range 333-393K for slowly cooled and quenched samples. The quenching samples indicated an improvement in the mechanical properties. The energy activated the rate controlling mechanisms has been calculated and found to be 17.85 and 24.57 kJ/mol for slowly cooled and quenched samples respectively. These values were found to be close to those reported for the grain boundary sliding mechanism in Sn-based alloys.nbs

Neutral Higgs-pair production at Linear Colliders within the general 2HDM: quantum effects and triple Higgs boson self-interactions

The pairwise production of neutral Higgs bosons is analyzed in the context of the future linear colliders, such as the ILC and CLIC, within the general Two-Higgs-Doublet Model (2HDM). The corresponding cross-sections are computed at the one-loop level in full compliance with the current phenomenological bounds and the stringent theoretical constraints inherent to the consistency of the model. We uncover regions across the 2HDM parameter space, mainly for low tan\beta near 1 and moderate values of the relevant lambda_5 parameter, wherein the radiative corrections to the Higgs-pair production cross sections can comfortably reach 50% This behavior can be traced back to the enhancement capabilities of the trilinear Higgs self-interactions -- a trademark feature of the 2HDM, with no counterpart in the Minimal Supersymmetric Standard Model. Interestingly enough, the quantum effects are positive for energies around 500 GeV, thereby producing a significant enhancement in the expected number of events precisely around the fiducial startup energy of the ILC. The Higgs-pair production rates can be substantial, typically amounting to a few thousand events per 500 inverse femtobarn of integrated luminosity. In contrast, the corrections are negative in the highest energy range (1 TeV). We also compare the exclusive pairwise production of Higgs bosons with the inclusive gauge boson fusion channels leading to 2H+X finals states, and also with the exclusive triple Higgs boson production. We find that these multiparticle final states can be highly complementary in the overall Higgs bosons search strategy.Comment: 42 pages, 23 figures, 10 tables. Accepted in Phys. Rev. D (the published version is shorter

Decision Agriculture

In this chapter, the latest developments in the field of decision agriculture are discussed. The practice of management zones in digital agriculture is described for efficient and smart faming. Accordingly, the methodology for delineating management zones is presented. Modeling of decision support systems is explained along with discussion of the issues and challenges in this area. Moreover, the precision agriculture technology is also considered. Moreover, the chapter surveys the state of the decision agriculture technologies in the countries such as Bulgaria, Denmark, France, Israel, Malaysia, Pakistan, United Kingdom, Ukraine, and Sweden. Finally, different field factors such as GPS accuracy and crop growth are also analyzed

Caracterización estructural y actividad biológica de sulfolípidos de algas marinas seleccionadas

The sulfolipid classes (SLs) in the total lipids of five species of marine algae, two species of Rhodophyta (Laurencia popillose, Galaxoura cylindriea), one species of Chlorophyta (Ulva fasciata), and two species of Phaeophyta (Dilophys fasciola, Taonia atomaria) were separated and purified on DEAE-cellulose column chromatography. The SLs component was identified by IR, gas chromatography MS/MS and liquid chromatography MS/MS. The level of SLs contents va ried from 1.25% (in L. papillose) to 11.82% (in D. fasciola) of the total lipid contents. However, no significant differences in sulfate content (0.13 – 0.21%) were observed among all these algae species. All SLs were characterized by high contents of palmitic acid (C 16:0), which ranged from 30.91% in G. cylindriea to 63.11% in T. atomatia. The main constitutes of algal sulfolipids were identified as sulfoquinovosyl-di-acylglycerol and sulfoquinovosyl acylglycerol. The sulfolipids of different algal species exhibited remarkable antiviral activity against herps simplex virus type 1 (HSV-1) with an IC50 ranging from 18.75 to 70. 2 μg mL–1. Moreover, algal sulfolipid inhibited the growth of the tumor cells of breast and liver human cancer cells with IC50 values ranging from 0.40 to 0.67 μg mL–1 for human breast adenocarcinoma cells (MCF7).Se separaron diferentes clases sulfolípidos (SL) a partir de los lípidos totales de cinco especies de algas marinas: una especie de Chlorophyta (Ulva fasciata), dos especies de Phaeophyta (Dilophys fasciola, Taonia atomaria) y dos especies de Rhodophyta (Laurencia popillose, Galaxoura cylindriea) que se purificaron mediante cromatografía en columna de DEAE-celulosa. Los components de SLs fueron identificados por IR, cromatografía de gases MS/MS y cromatografía líquida MS/ MS. Los contenidos de SL en relación al total de lípidos varió de 1,25% (en L. papilosa) al 11,82% (en D. fasciola). Sin embargo, no hay diferencias significativas en el contenido de sulfato observado entre todas estas especies de algas (desde 0,13 hasta 0,21%). Todos los SL se caracterizaron por un alto contenido de ácido palmítico (C16:0), que osciló entre 30,91% en G. cylindriea a 63,11% en T. atomatia. Sulfoquinovosyl-di-acilglicerol y acilglicerol sulfoquinovosyl fueron identificados como los principales constituyentes de los sulfolípidos de estas algas. Los sulfolípidos de las diferentes especies de algas estudiadas mostraron una notable actividad antiviral contra el virus del herpes simple tipo 1 (VHS-1) con una IC50 que osciló entre 18,75 y 70. 2 g mL–1. Por otra parte, los sulfolípidos de estas algas inhibieron el crecimiento de células tumorales de mama y células de cáncer de hígado humano con valores de IC50 que van desde 0,40 hasta 0,67 g mL–1 para las células de adenocarcinoma de mama humano (MCF7)

The semileptonic decays of the B_c meson

We study the semileptonic transitions B_c to \eta_c, J/\psi, D, D^*, B, B^*, B_s, B_s^* in the framework of a relativistic constituent quark model. We use experimental data on leptonic J/\psi decay, lattice and QCD sum rule results on leptonic B_c decay, and on radiative \eta_c transitions to adjust the quark model parameters. We compute all form factors of the above semileptonic B_c-transitions and give predictions for various semileptonic B_c decay modes including their \tau-modes when they are kinematically accessible. The implications of heavy quark symmetry for the semileptonic decays are discussed and are shown to be manifest in our explicit relativistic quark model calculation. A comparison of our results with the results of other calculations is performed.Comment: 31 pages Latex (uses epsf, revtex). Section II expanded, typos corrected. This version will appear in Phys. Rev.