A Microgravity Science and Applications Program overview

Biological systems and processes have had, and continue to have, important implications and applications in materials extraction, processing, and performance. This paper illustrates some interdisciplinary, biological issues in materials science and engineering. These include metal extraction involving bacterial catalysis, galvanic couples, bacterial-assisted corrosion and degradation of materials, biosorption and bioremediation of toxic and other heavy metals, metal and material implants and prostheses and related dental and medical biomaterials developments and applications, nanomaterials health benefits and toxicity issue, and biomimetics and biologically inspired materials developments. These and other examples provide compelling evidence and arguments for emphasizing biological sicences in materials science and engineering curricula and the implementation of a bio-materials paradigm to facilitate the emergence of innovative interdisciplinarity involving the biological sciences and materials sciences and engineering.

During ground-based solidification, buoyancy flow can develop by the density difference in the hypoeutectic type of the alloys, such as Al-7 wt% Si alloy. Buoyancy flow can affect the thermal field, solute distribution in the melt, and the position and amount of the new grains. As solidification is a very complex process, it is not very easy to separate the different effects. Under microgravity conditions, natural convection does not exist or is strongly damped due to the absence of the buoyancy force. Therefore, experiments in microgravity conditions provide unique benchmark data for pure diffusive solidification conditions. Compared to the results of the ground-based and microgravity experiments, it is possible to get information on the effect of gravity (buoyancy force). In the framework of the CETSOL project, four microgravity solidification experiments were performed on grain refined (GF) and non-grain refined Al-7 wt% Si alloy onboard the International Space Station in the Materials Science Laboratory. These experiments aimed to study the effect of the solidification parameters (solid/liquid front velocity vSL, temperature gradient GSL) on the grain structure and dendritic microstructures. The microgravity environment eliminates the melt flow, which develops on Earth due to gravity. Four ground-based (GB) experiments were performed under Earth-like conditions with the same (similar) solidification parameters in a vertical Bridgman-type furnace having four heating zones. The detailed analysis of the grain structure, amount of eutectic, and secondary dendrite arm spacing (SDAS) for different process conditions is reported and compared with the results of the microgravity experiments. GB experiments showed that the microstructure was columnar in the samples that do not contain GF material or in case the solid/liquid (vSL front velocity was slow (0.02 mm/s)). In contrast, in the sample which contained GF material, progressive columnar/equiaxed transition (PCET) was observed at vSL = 0.077 mm/s and GSL = 3.9 K/mm. The secondary (SDAS) dendrite arm spacing follows the well-known power law, SDAS=K[t0]13, where K is a constant, and t0 is the local solidification time for both GB and µg experiments.

From the Ground Up-Materials Science in Singapore.

This paper briefly reviews the applications of materials science and engineering in the pharmaceutical industry. The materials characterization techniques highlighted in the paper as being utilized in the pharmaceutical industry are dynamic light scattering and photon correlation spectroscopy, mercury intrusion, gas density pycnometry and energy density analysis, thermogravimetric analysis and differential scanning calorimetry, x-ray diffraction, nuclear magnetic resonance and Raman microscopy. The other areas of applications of materials science and engineering in the pharmaceutical industry briefly discussed are materials processing, materials research and development, and materials selection. This paper further highlighted that the program as it is currently offered by various institutions in Nigeria is yet to incorporate the courses in pharmaceutical materials. It concluded by pointing out that some institutions outside Nigeria have incorporated pharmaceutical materials in the programs of materials science and engineering. Suggestions were made for the materials science and engineering programs in Nigeria to build further capacity for effective applications in the pharmaceutical industry. Keywords— Applications, materials engineering, pharmaceutical industry

To understand gravity resistance in plants, it is necessary to analyze the changes induced when the magnitude of gravity in a growth environment is modified. Microgravity in space provides appropriate conditions for analyzing gravity resistance mechanisms. Experiments carried out in space involve a large number of constraints and are quite different from ground-based experiments. Here, we describe basic procedures for space-based experiments to study gravity resistance in plants. An appropriate cultivation chamber must be selected according to the growing period of the plants and the purpose of the experiment. After cultivation, the plant material is fixed with suitable fixatives in appropriate sample storage containers such as the Chemical Fixation Bag. The material is then analyzed with a variety of methods, depending on the purpose of the experiment. Plant material fixed with the RNAlater® solution can be used sequentially to determine the mechanical properties of the cell wall, RNA extraction (which is necessary for gene-expression analysis), estimate the enzyme activity of cell wall proteins, and measure the levels and compositions of cell wall polysaccharides. The plant material can also be used directly for microscopic observation of cellular components such as cortical microtubules.

The article deals with materials science issues concerning the application areas in dental engineering. The monograph aims to present the results of the Author’s work against the background of general achievements, indicating the engineering aspects of dental implant-prosthetic treatment. They include clinical cases, most often concerning complete edentulism, with a detailed discussion of the methodology of the material, technological, and structural design of dental prosthetic restorations, especially the impact of additive manufacturing conditions and surface engineering technology on the mechanical properties and structure of prosthetic restorations.The monograph covering the engineering and technical activities of implant prosthetic treatment includes the Author's aspects concerning the development of the methodology of computer-aided design of dental prosthetic restorations and surgical guides ensuring their correct installation in the oral cavity of patients, along with virtual modelling of treatment plans, modelling of the load status of individual elements of implant-prosthetic systems, development of the methodology of computer-aided production of elements of the prosthetic restoration system as well as implants and implant-scaffolds with the use of milling technology in CNC centres and additive manufacturing by selective laser sintering, the results of research on the influence of additive manufacturing conditions on the structure and properties of titanium and its alloy Ti6Al4V and cobalt alloy Co25Cr5W5MoSi containing studies of biochemical properties for applications for implant-prosthetic purposes in dentistry, the results of tests on the influence of ALD atomic layer conditions on the structure and surface properties of metals and their alloys used in implant-prosthetic treatment in dentistry and the results of tests of prosthetic fillings used in the treatment of Tooth decay.The basis for all the described achievements of the monograph are the comprehensive results of research related to the study of the structure and properties of engineering materials, especially titanium and cobalt alloys used in dentistry, subjected to additive manufacturing using the Selective Laser Sintering SLS method and surface treatment using the Atomic Layer Deposition ALD method, as a domain of materials engineering, in the context of the Industry Integrated Idea 3xI 4 model. 0/5.0 and the 6xE 6 Expectation Principle, which there is a paradigm for materials science. What is important in the approach are the results of biological tests of materials produced in such a way, leading to numerous applications in the Author’s clinical practice in cooperation with dentists and the development of a general concept of a research, design, and production centre for prosthetic restorations and virtual acquisition of diagnostic data from cooperating dental clinics.The article is a monographic study referring to numerous of the Author’s publications, patents, and presentations at scientific conferences and invention fairs, in which very extensive source information is provided concerning both a very large number of literature items and extensive factual material, including the results of materiallographic studies and descriptions of clinical cases, although this study also presents numerous aspects not yet published in any previous works.The study presents, among others, detailed prosthetic and implant-prosthetic solutions implemented by the Author of the study and successfully used by patients. Although the study is formally qualified in the engineering and technical sciences in materials engineering, it has strong links with biomedical engineering and the applied area of interventional dentistry.Numerous original publications, patent solutions, completed projects, and awards at the International Innovation Fair discussed in the monograph, as well as clinical experience related to the treatment of thousands of dental patients in our Author’s clinic, confirm the originality of the approach and indicate the innovative nature of the achievements presented in the article so far. Many years of experience have led to the launch of a constantly developed production centre for prosthetic restorations and a virtual structure for obtaining diagnostic data from cooperating dental clinics. The article addresses scientists dealing with materials engineering applied in interventional dentistry and dental engineers in practice dealing with this issue.

Development of hydrogels with excellent and tunable mechanical properties combining with multifunctions is an intriguing issue in material science and engineering. Herein, bioinspired tunable sacrificial bonds are introduced into the tetra‐poly(ethylene glycol) (PEG) based polyurethane (PU) (TP) network to afford a hydrogel with tunable mechanical properties, shape‐memory, and self‐healing functions. The mussel‐inspired compound of Lysine‐dopamine (LDA) is introduced into the network of TP hydrogel through polyurethane/polyurea chemistry to form LDA‐tetra‐PEG‐PU (LTP) hydrogel. As catechol groups in LDAs can intermolecularly interact with each other and can also coordinate with ferric ions with different coordination ratios, these physical interactions with different strengths in the afforded LTP hydrogel construct kinds of sequentially tuned sacrificial bonds. As a result, these sacrificial bonds preferentially rupture prior to the covalent network upon external loading, which dissipate the energy and endow the hydrogel with advanced and postadjustable mechanical properties. This mechanism is investigated in detail. Furthermore, the LTP hydrogel shows multifunctions such as shape‐memory and self‐healing abilities. In addition, the tetra‐PEG based hydrogel shows remarkable thermoresponsiveness that the hydrogel distinctly contracts with the increase of the temperature. The improved mechanical strength and multifunctions should enlarge the application areas of the tetra‐PEG based hydrogel in various fields.

Training data augmentation: An empirical study using generative adversarial net-based approach with normalizing flow models for materials informatics

120 Years of nickel-based cathodes for alkaline batteries

Metal–insulator (MI) transitions in correlated electron systems have long been a central and controversial issue in material science. Vanadium dioxide (VO2) exhibits a first-order MI transition at 340 K. For more than half a century, it has been debated whether electron correlation or the structural instability due to dimerised V ions is the more essential driving force behind this MI transition. Here, we show that an ultrahigh magnetic field of 500 T renders the insulator phase of tungsten (W)-doped VO2 metallic. The spin Zeeman effect on the d electrons of the V ions dissociates the dimers in the insulating phase, resulting in the delocalisation of electrons. As the Mott–Hubbard gap essentially does not depend on the spin degree of freedom, the structural instability is likely to be the more essential driving force behind the MI transition.

Today, computational models are extensively applied in scientific research to address fundamental as well as practical issues in material science. Fullerenes and metallofullerenes are well recognized as potential materials for next-generation electronic devices, such as quantum computers. The rapid advance in fullerene/metallofullerene research requires improved theoretical tools to understand fundamental as well as practical applications of these new members of fullerene/metallofullerene family. In this presentation, we will describe the extension of the famous spiral program by Fowler and Manolopoulos1 to generate new non-classical isomers. We have extended this approach beyond 5 and 6 membered fullerene structures to other polygon faces, such as, heptagons. In addition, we have developed a machine learning tool based on a general relationship between the structure patterns and physical properties. Finally, we will describe our current modeling studies regarding chromatographic retention mechanism(s) of fullerene/metallofullerene molecules. Reference: Fowler, Patrick W., and D. E. Manolopoulos. An Atlas of Fullerenes. Clarendon Press-Oxford, 1995.

A major issue in materials science is why glasses present low-temperature thermal and vibrational properties that sharply differ from those of crystals. In particular, long-wavelength phonons are considerably more damped in glasses, yet it remains unclear how structural disorder at atomic scales affects such a macroscopic phenomenon. A plausible explanation is that phonons are scattered by local elastic heterogeneities that are essentially uncorrelated in space, a scenario known as Rayleigh scattering, which predicts that the damping of acoustic phonons scales with wavenumber k as kd+1 (in dimension d). Here we demonstrate that phonon damping scales instead as - kd+1 lnk, with this logarithmic enhancement originating from long-range spatial correlations of elastic disorder caused by similar stress correlations. Our work suggests that the presence of long-range spatial correlations of local stress and elasticity may well be the crucial feature that distinguishes amorphous solids from crystals.

Prediction of fracture toughness of ceramic composites as function of microstructure: I. Numerical simulations

Unravelling dislocation networks in metals

A novel method to study recrystallization behavior: Continuous heating stress relaxation