An Empirical Evaluation of the Cost and Effectiveness of Structural Testing Criteria for Concurrent Programs

AbstractConcurrent program testing is not a trivial task. Features like nondeterminism, communication and synchronization impose new challenges that must be considered during the testing activity. Some initiatives have proposed testing approaches for concurrent programs, in which different paradigms and programming languages are considered. However, in general, these contributions do not present a well-formed experimental study to validate their ideas. The problem is that the data used and generated during the validation is not always available, hampering the replication of studies in the context of other testing approaches. This paper presents an experimental study, taking into account the concepts of the Experimental Software En- gineering to evaluate the cost, effectiveness and strength of the structural testing criteria for message-passing programs. The evaluation was conducted considering a benchmark composed of eight MPI programs. A set of eight structural testing criteria defined for message-passing programs was evaluated with the ValiMPI testing tool, which provides the support required to apply the investigated testing criteria. The results indicate the complementary aspect of the criteria and the information about cost and effectiveness has contributed to the establishment of an incremental testing strategy to apply the criteria. All material generated during the experimental study is available for further comparisons

Effects of macrosegregation and microstructure on the corrosion resistance and hardness of a directionally solidified Zn-5.0wt.%Mg alloy

This study aims to analyze the influence of macrosegregation on microstructure evolution, and of microstructure length scale on the corrosion resistance of a Zn-5.0wt.%Mg alloy casting. The analyzed samples were taken along the length of castings unidirectionally solidified in unsteady state conditions of heat extraction. Microstructure characterization, microhardness, linear polarization and electrochemical impedance spectroscopy (EIS) tests were performed. A unique type of microstructure was observed, characterized essentially by a morphology typified by idiomorphic MgZn2 crystals in a “complex eutectic mixture” [coexistence of stable (Zn+Mg2Zn11) and metastable (Zn+MgZn2) eutectics]. The correlation between thermal and microstructural parameters, permitted experimental growth laws, correlating the evolution of the lamellar eutectic spacing with the cooling rate to be established. Vickers microhardness and electrochemical corrosion tests showed that more refined microstructures associated with higher experimental cooling rates, are related to a better set of higher hardness and corrosion resistance221CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP155863/2013-4; Project i-link0944; 166912/2017-4não tem2012/08494-0; 2013/15478-3; 2013/25452-1; 2013/23396-7; 2014/50502-

Estudo da suscetibilidade ao escurecimento por radiação gama de quartzo róseo-leitoso da província pegmatítica da Borborema

Este estudo considera as transformações induzidas pela radiação γ sobre os defeitos estruturais em quartzo róseo e leitoso da Província Pegmatítica da Borborema (Paraíba e Rio Grande do Norte, Brasil). Amostras de coloração rósea e leitosa foram irradiadas com doses de raios γ (60Co) entre 0,5 e 96 kGy. Defeitos pontuais relacionados às impurezas de Al, Ge, Li e grupos OH foram caracterizados por espectroscopias ultravioleta visível e infravermelha e ressonância paramagnética eletrônica, antes e após a irradiação. A espectrometria de massa com plasma indutivamente acoplado foi empregada para quantificar as concentrações de Al, Li, Ge, Fe, Ti e outras impurezas em fragmentos de diferentes tonalidades. Constatou-se que os defeitos [AlO4]0, [AlO4/H]0 e [GeO4/Li]0 são formados pela dissociação dos defeitos [AlO4/Li]0 e [Li-OH], a partir de doses de 0,5 kGy. A diminuição do sinal da ressonância paramagnética eletrônica do centro [GeO4/Li]0 e a formação de centros E'1 perturbados por Ge para doses acima de 8 kGy confirmou a grande mobilidade dos íons Li+ pela estrutura do quartzo. O aumento da população de defeitos [AlO4]0 e o consequente escurecimento das amostras foi semelhante para ambos os tipos de quartzo. Análises preliminares por microscopia eletrônica mostraram a presença de fibras nanométricas apenas no resíduo da digestão ácida de amostras róseas, indicando que a coloração rósea do quartzo da Província Pegmatítica da Borborema está provavelmente relacionada às inclusões de dumortierita

Development Of Soft-glasses Photonic Crystal Fiber Made By Stacking-and-draw Technique

We have been able to produce soft glass conventional core-clad and micro-structured fibers using rod-and-tube and stack-and-draw method respectively. The stack-and-draw technique shows several difficulties when used with soft glasses, that we managed to avoid using two different lead and alkaline glasses. Non commercial glasses and fibers were thermo-mechanically and optically characterized.6469White, T.P., McPhedran, R.C., de Sterke, C.M., Botten, L.C., Steel, M.J., Confinement losses in micro structure optical fibers (2001) Opt. Lett, 26 (21), p. 1660Russell, P., Photonic crystal fibers (2003) Science, 299, pp. 358-362Knight, J.C., Photonic crystal fibers (2003) Nature, 424, pp. 847-851Chillcce, E.F., Cordeiro, C.M., Rodriguez, E., Brito Cruz, C.H., Cesar, C.L., Barbosa, L.C., Tellurite photonic crystal with Er 3+-Tm3+ for broadband optical amplifier in 1550nm (2006) Proc. of SPIE, 6116, p. 611604A. Hruby, Czech J. Phys. B, Evaluation of glass-forming tendency by means of DTA 1972, 22, 118

Apoptosis in human liver carcinoma caused by gold nanoparticles in combination with carvedilol is mediated via modulation of MAPK/Akt/mTOR pathway and EGFR/FAAD proteins

Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas