Coexistence of adjacent vacancy-ordered and eutectic phases in Al–Cu–Ni alloys

ABSTRACT

Copper-mould-cast Al–Cu–Ni alloys show adjacent coexistence of in situ grown ordered and eutectic phases. A bimodal microstructure of α–Al and eutectic α-Al+θ-Al₂Cu phases with length-scale hierarchy evolves during solidification. Microstructural analysis through Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) shows the presence of Vacancy-ordered phases (VOPs) with different morphologies in two different compositions.     

On the synthesis and characterisation of novel composite-structured high-entropy alloys

A study of novel composite-structured CoCrFeNi₃Si, CoCrFe₂Ni₂Si and Co₂CrFeNi₂Si high-entropy alloys, synthesised by vacuum arc melting, is presented. The designing criteria for the formation of such alloys were based on the enthalpy of mixing and the valence electron concentration. X-ray diffraction analysis revealed that all the alloys were composed of face-centered cubic and intermetallic phases. Scanning electron microscopy, along with elemental analysis, indicated that the face-centered cubic phase mainly contains Co, Cr, Fe and Ni, whereas, the intermetallic compound is Ni-Si rich. All the synthesised high-entropy alloys in the present investigation possess excellent compressive strength along with ductility at room temperature, suggesting significant potential application in the engineering field. Furthermore, enhanced hardness, wear resistance and corrosion resistance were achieved in all the designed high-entropy alloys. The previously given design parameters for the composite-structured high-entropy alloys are in good accord with the current research work.     

Evolution of grain-boundary character distribution during iterative processing of an austenitic stainless steel

The present article deals with the analysis of grain-boundary character distribution (GBCD) and microstructural characteristics after iterative processing of austenitic stainless steel, AISI 316L. The steel was subjected to iterative cold reduction and subsequent annealings. After an initial decrease in the fraction of Σ3 boundaries, the number of these increases in subsequent steps. The results relate the importance of iterative processing and the mechanism of obtaining a higher fraction of Σ3 boundaries.     

Composition dependence of the activation energy of the glass transition in some chalcogenide glasses

The activation energy (E _t) of the glass transition process has been obtained for glassy Se_{80? x} Te₂₀M _x (M = Ag, Cd, In, Sb) and Se_{100? x} M _x (M = In, Te, Sb) systems using differential scanning calorimetry. The composition dependence of E _t is explained in terms of fragility index for the systems. A reversal in the trend of the E _t is explained using topological models.     

Effect of lithium-ion irradiation on the crystallization kinetics of glassy Se98In2

Differential scanning calorimetry (DSC) has been used to study the crystallization kinetics of glassy Se₉₈In₂ both before and after irradiation of the alloy with high-energy (50 MeV) lithium ions. After the ion-irradiation, significant changes in the kinetic parameters of crystallization of the glass were observed. The results are explained in terms of a model involving irradiation-induced defects.     

Negative,zero and positive stiffness in extended Eshelby plates

Structures under loading can show positive and negative stiffness (during buckling) with zero stiffness just being one point of transition. Material structures with extended zero stiffness regimes have also been reported. Using the example of an extended Eshelby plate with a positive and negative edge dislocation, we show the existence of finite regimes of positive, zero and negative stiffness in a single system. Given that stable states/configurations of negative stiffness cannot exist in an isolated system; we show the existence of metastable states of negative stiffness along with unstable states of positive stiffness. The system also exhibits one point of unstable equilibrium.     

Language proficiency does not modulate executive control in older bilinguals

ABSTRACT

We examined if language proficiency modulates performance in tasks that measure executive control in older Telugu-English bilinguals (n = 50, mean age = 57.15 years). We administered numerical Stroop task, Attention Network Task, Dimensional Change Card Sorting task, and stop-signal task that are known to tap into different aspects of executive functioning on healthy aging Telugu-English bilinguals. Second language (English) proficiency was calculated as a cumulative score that considered both subjective and objective measures of L2 fluency and use. Bilinguals were divided into two groups based on the cumulative score and compared on each task. We did not find any effect of language proficiency on any of the executive control measures. The additional Bayesian analysis also supported these findings. Therefore, the results do not support the claim that bilingual language proficiency modulates executive control, at least in the elderly population. We discuss the results with regard to the issue of bilingual advantage in executive control and the role of age and language use.     

Ethical Conflicts in Commercialization of University Research in the Post–Bayh–Dole Era

Protection of intellectual property as well as its exploitation for monetary benefit have existed for centuries. However, commercialization of intellectual property had not entered the precincts of academic universities in a significant way until the introduction of the Bayh–Dole Act in the 1980s in the United States. The post–Bayh–Dole era has seen a quantitative increase in patenting activity in universities. This article summarizes the ethical conflicts ushered in by increasing commercialization of academic university research. Activities related to the protection and commercial exploitation of intellectual property have led to changes in academic culture that have given room for debate between the puritans and the modernists. Issues contended by the two groups have been identified, and both sides of the argument are discussed. The key to achieving “responsible commercialization of research” is to balance the Bayh–Dole ethos with the traditional Mertonian norms of academic research.     

Attention in Sentence Processing: A Review

This review looks at the relationship between attention and language. There have been many studies that have shown a certain role of attention on sentence and spoken word processing. At the same time some other studies have observed that language processing is autonomous. In this review an attempt has been made to review the empirical evidence from sentence processing in reading, auditory processing and speaking domains to see if attentional manipulations cause interference with processing. The review suggests currently available evidence is rather mixed and it is still a long way to fully explore the attentional basis of sentence processing.     

Mathematical Intelligence and Mathematical Creativity: A Causal Relationship

This study investigated the causal relationship between mathematical creativity and mathematical intelligence. Four hundred thirty-nine 8th-grade students, age ranged from 11 to 14 years, were included in the sample of this study by random cluster technique on which mathematical creativity and Hindi adaptation of mathematical intelligence test were administered with 4-month time lag. Cross-lagged panel analysis was used to analyze the data. The uncorrected cross-lagged correlations appeared to show no causal relation between mathematical creativity and mathematical intelligence. But after the correction the difference in the cross-lagged correlations was found to be small and does not give guarantee of unidirectional causal relation between these two constructs. It revealed that there is a mutually reinforcing (symmetric) relationship between mathematical intelligence and mathematical creativity, i.e., mathematical intelligence causes mathematical creativity and vice-versa.