다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

Biodegradable metals are breaking the current paradigm in biomaterial science to develop only corrosion resistant metals. In particular, metals which consist of trace elements existing in the human body are promising candidates for temporary implant materials. These implants would be temporarily needed to provide mechanical support during the healing process of the injured or pathological tissue. Magnesium and its alloys have been investigated recently by many authors as a suitable biodegradable biomaterial. In this investigative review we would like to summarize the latest achievements and comment on the selection and use, test methods and the approaches to develop and produce magnesium alloys that are intended to perform clinically with an appropriate host response.

/pdf/degradable-biomaterials-based-on-magnesium-corrosion-4sw919tlb2.pdf

Degradable biomaterials based on magnesium corrosion

https://material.karlov.mff.cuni.cz/people/janecek/studenti/FyzMetNano/Estrin_AM61_2013_782.pdf

Extreme grain refinement by severe plastic deformation: A wealth of challenging science

The objective of this study is to review and evaluate the applications of magnesium in the automotive industry that can significantly contribute to greater fuel economy and environmental conservation. In the study, the current advantages, limitations, technological barriers and future prospects of Mg alloys in the automotive industry are given. The usage of magnesium in automotive applications is also assessed for the impact on environmental conservation. Recent developments in coating and alloying of Mg improved the creep and corrosion resistance properties of magnesium alloys for elevated temperature and corrosive environments. The results of the study conclude that reasonable prices and improved properties of Mg and its alloys will lead to massive use of magnesium. Compared to using alternative materials, using Mg alloys results in a 22% to 70% weight reduction. Lastly, the use of magnesium in automotive components is increasing as knowledge of forming processes of Mg alloys increases.

Magnesium and its alloys applications in automotive industry

Evolution of microstructure and texture for an Al-0.4 Er alloy during accumulative roll bonding

Magnesium alloy corrosion is often nonlinear. The corrosion rate accelerates to steady state after an initial period of low corrosion. Plug-in specimens permit simultaneous measurement of the corrosion rate using hydrogen evolution, PH, and Tafel extrapolation of cathodic polarization curves, Pi. Moreover, weight loss allows independent verification. PH is consistently greater than Pi. The data, for short exposure periods up to 10 days, are consistent with the unipositive Mg+ ion being a short-lived intermediate. Tafel extrapolation needs to be used with caution for estimation of Mg corrosion, as the measured corrosion rate can have a significant contribution from crevice corrosion. Furthermore, measurements made at short immersion times may not reflect the steady-state corrosion rate, and the corrosion reaction at the Mg surface may be decoupled from the electrochemical measurement.

Plug-In Specimens for Measurement of the Corrosion Rate of Mg Alloys

We report the concurrence of de-alloying and re-alloying in a ternary Al67Cu18Sn15 alloy (at.%) de-alloyed in a 5 wt% hydrochloric acid (HCl) solution at 70 ± 2 °C, and the fabrication of three-dimensional (3D) nanoporous Cu3Sn–Cu–Cu6Sn5 composites in the form of self-supporting foils. Re-alloying occurred in Al67Cu18Sn15 compared to de-alloying alone in binary Al–Cu alloys. Both Cu3Sn and Cu6Sn5 phases formed through an accompanied re-alloying process. This finding further proves the temperature sensitivity of phase formation in the Cu–Sn system established from Cu–Sn diffusion couple studies, and demonstrates the capability of designing and creating nanoporous composite materials via de-alloying a multicomponent alloy.

Concurrence of de-alloying and re-alloying in a ternary Al67Cu18Sn15 alloy and the fabrication of 3D nanoporous Cu–Sn composite structures

Two distinct roles of Al2Sm and Al11Sm3 phases on the corrosion behavior of the magnesium alloy Mg-5Sm-xAl

The identity of carbide precipitates resulting from autotempering in as-quenched 3. 5 NiCrMoV rotor steel has been rigorously examined. Tempering for 5 hrs at 500 degree C produces only marginal coarsening of Widmanstaetten carbides, but results in the appearance of additional carbides at the boundaries of microtwins. Carbides in the tempered steel are readily identified as cementite, and have provided an understanding of the relationship between the diffraction patterns produced by double difraction and cementite at microtwin boundaries. This relationship is found in some cases to result in coincidence of the two types of pattern, so that cementite spots are obscured by double diffraction spots. This partly explains the lack of unequivocal cementite spots in the as-quenched steel. Dark field imaging and statistical analysis have shown that in the tempered steel, in some of the diffraction patterns which have contributions from both double diffraction and cementite, the contribution from cementite is major. By contrast, the contribution to such patterns in the as-quenched steels is minor.

Andrej Atrens

Papers

Evolution of microstructure and texture for an Al-0.4 Er alloy during accumulative roll bonding

Plug-In Specimens for Measurement of the Corrosion Rate of Mg Alloys

Concurrence of de-alloying and re-alloying in a ternary Al67Cu18Sn15 alloy and the fabrication of 3D nanoporous Cu–Sn composite structures

Two distinct roles of Al2Sm and Al11Sm3 phases on the corrosion behavior of the magnesium alloy Mg-5Sm-xAl

Microstructure of as‐quenched 3.5 NiCrMoV rotor steel. Part III. Carbide Precipitation