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During in situ cyclic testing of hot isostatically pressed and heat-treated Al-5Si-0.5 Mg-1Cu alloy castings, cracks were observed to open up in places far away from the area of stress concentration. Cyclic testing was interrupted to assess these cracks. Analysis showed that these cracks originated from oxide bifilms that were entrained in the liquid state. Moreover, Si and Fe-rich intermetallics were observed to have precipitated on these bifilms. These finding makes it necessary to re-evaluate how damage is interpreted in mechanical studies. Entrainment damage, which takes place in the liquid state, may remain invisible in non-destructive inspection and can significantly affect fatigue properties when bifilms open up under low tensile stresses and present the propagating crack a path of low resistance during propagation.

Iron-Cobalt (FeCo) columnar, multilayered structure is prepared by depositing several thin FeCo layers by varying the angle between the surface normal and the evaporation direction as 0 (normal) and 60(oblique), alternatively. In situ X-ray scattering and magneto-optical Kerr effect (MOKE) measurements established the evolution of magnetic properties with that of the morphology and structure of the multilayer. The strong shape anisotropy and compressive stress of nanocolumns in alternative FeCo layers resulted in a well-defined uniaxial magnetic anisotropy (UMA) with the easy axis of magnetization along the projection of the tilted nanocolumns in the film plane. The stress in the film provides minimization of magnetoelastic energy along the in-plane column direction, which couples with the columnar shape anisotropy energies and results in the preferential orientation of the magnetic easy axis along the oblique angle deposition direction in the film plane. Drastic reduction in the in-plane UMA after annealing at 450 C is attributed to the merging of columns and removal of stresses after heat treatment. The present study opens a new pathway to produce magnetically anisotropic multilayer structures using single material and thus may have prominent implications for future technological devices., QC 20220525

Smartphone photography is gaining popularity among young adults and can be used for expressing mood. However, how photos are used for expressing happiness is understudied. This paper presents the findings of a study involving 27 college students who were instructed to take one photo daily representing a happy moment for three weeks. The participants also viewed their daily photos three times a day and reported their mood at the time. Results show that while users reported positive feelings in general, the feeling was calmer for individuals who took photos to make others happy than for those whose photos were intended to make themselves happy. Although food is the most frequent photo theme in this study, photos about social connections evoke the strongest happy sensation. Other common photo themes associated with happiness include entertainment, personal achievement, and nature. We offer insights into enhancing young adults' mental well-being using smartphone photography that integrates prosocial behavior and vitalizes links to strong ties. © 2017 IEEE.

Smartphone photography is gaining popularity among young adults and can be used for expressing mood. However, how photos are used for expressing happiness is understudied. This paper presents the findings of a study involving 27 college students who were instructed to take one photo daily representing a happy moment for three weeks. The participants also viewed their daily photos three times a day and reported their mood at the time. Results show that while users reported positive feelings in general, the feeling was calmer for individuals who took photos to make others happy than for those whose photos were intended to make themselves happy. Although food is the most frequent photo theme in this study, photos about social connections evoke the strongest happy sensation. Other common photo themes associated with happiness include entertainment, personal achievement, and nature. We offer insights into enhancing young adults' mental well-being using smartphone photography that integrates prosocial behavior and vitalizes links to strong ties. © 2017 IEEE.

Smartphone photography is gaining popularity among young adults and can be used for expressing mood. However, how photos are used for expressing happiness is understudied. This paper presents the findings of a study involving 27 college students who were instructed to take one photo daily representing a happy moment for three weeks. The participants also viewed their daily photos three times a day and reported their mood at the time. Results show that while users reported positive feelings in general, the feeling was calmer for individuals who took photos to make others happy than for those whose photos were intended to make themselves happy. Although food is the most frequent photo theme in this study, photos about social connections evoke the strongest happy sensation. Other common photo themes associated with happiness include entertainment, personal achievement, and nature. We offer insights into enhancing young adults' mental well-being using smartphone photography that integrates prosocial behavior and vitalizes links to strong ties. © 2017 IEEE.

The temperature stability of cubic TiO1.05 titanium monooxide is investigated. An in situ X-ray structural analysis is performed using synchrotron radiation in a high temperature vacuum chamber. It is found that under poor vacuum and at high heating rates of up to 1250 C, the structural transformations in TiO1.05 occur at 630 C. In particular, there is a phase transition from TiO1.05 (space group Fm-3m) to rhombohedraic Ti2O3 (space group R-3c) via Ti2.5O3 (space group Immm). © 2013 Allerton Press, Inc.

As part of a broader research program dealing with initial atmospheric corrosion of metals induced by organic acids, infrared reflection absorption spectroscopy (IRAS) has been used to study the initial interaction of acetic acid with zinc in 90% relative humidity and 120 ppb acid concentration under in situ condition. Efforts were made to quantify the identified reaction product species, mainly zinc oxide and zinc acetate. The experimentally obtained results were quantified through calculations using a linear relationship between IRAS peak intensity and layer thickness, and assuming optical constants of zinc acetate dihydrate (Zn(CH 3COO) 2•2H 2O). In all, the in situ studies performed by IRAS provide information on the identity and quantity of reaction products formed., QC 20141014

With the access and recent development of interface sensitive analytical techniques, it has become possible to perform molecular in situ analyses of the interfaces involved under ambient atmospheric pressure conditions. The initial indoor atmospheric corrosion of zinc has been investigated by vibrational sum frequency spectroscopy (VSFS). Vibrational sum frequency spectroscopy is an inherent surface sensitive technique which also gives information on the ordering of the molecules. It is used herein for probing the interface between the metal and the spontaneously formed aqueous adlayer. The zinc was exposed to humidified air to which formic acid (HCOOH) was added as corrosion stimulant. VSFS showed evidence of formate on the surface after exposure to 120 ppb formic acid, and the structure of the surface formates were seen to stabilize within approximately 90 minutes of exposure. This is in contrast with near-surface probing Infra red reflection absorption spectroscopy (IRAS) results which monitors a continuous increase in zinc formates beyond 90 minutes of exposure to formic acid and humid air. These results form evidence that the structure of the surface formates stays the same beyond 90 minutes of exposure, even though there is an ongoing corrosion process, as seen by the growth of the thin film of formates., QC 20141016

Organic molecular beam epitaxy (OMBE) is the growth technique assuring high quality films and properly designed multilayers of organic molecular materials in view of both their fundamental studies and applications. To monitor in-situ the OMBE growth, we have applied reflectance anisotropy spectroscopy (RAS), which is particularly effective and sensitive, being non destructive for organic materials. In this work, RAS is used to monitor, in-situ, the growth of organic heterostructures. The experiment is carried out using organic single crystals as substrates and oligothiophenes as molecular materials to build a stack of layers. A layer-by-layer growth of the films is demonstrated, together with the formation of interfaces with peculiar optical behavior and structure. © 2008 Elsevier Ltd. All rights reserved.

The problem of monitoring the structural and morphological evolutions of thin films of organic molecular materials during their growth by organic molecular beam epitaxy and in the postgrowth stage is addressed here by a combination of in situ optical reflectance anisotropy measurements, ex situ optical and morphological investigations, and theoretical simulation of the material optical response. For alpha-quaterthiophene, a representative material in the class of organic molecular semiconductors, the results show that molecules crystallize in the first stage of growth in metastable structures, even when deposition is carried out at room temperature. In the postdeposition stage, the film structure evolves within a few days to the known equilibrium structure of the low temperature polymorph. When deposition is carried out at low substrate temperatures, an evolution of the film morphology is also demonstrated. (c) 2007 American Institute of Physics

Reflectance anisotropy spectroscopy (RAS) has been employed to study in situ the growth of thin alpha-sexithiophene films by organic molecular beam deposition onto an organic substrate. A large anisotropy can be detected by following the line shape evolution of the RAS spectrum; in addition, the signal variation at a fixed wavelength is used to monitor the film growth. The signal intensity scales with the deposited thickness, demonstrating a very high sensitivity of RAS to less than 1/50 of a monolayer. Evidence of the advantages of RAS to monitor in real time the growth of molecular films and to probe in situ their properties is therefore obtained. (C) 2003 American Institute of Physics