Three-Dimensional Localized-Delocalized Anderson Transition in the Time Domain
NASA Astrophysics Data System (ADS)
Delande, Dominique; Morales-Molina, Luis; Sacha, Krzysztof
2017-12-01
Systems which can spontaneously reveal periodic evolution are dubbed time crystals. This is in analogy with space crystals that display periodic behavior in configuration space. While space crystals are modeled with the help of space periodic potentials, crystalline phenomena in time can be modeled by periodically driven systems. Disorder in the periodic driving can lead to Anderson localization in time: the probability for detecting a system at a fixed point of configuration space becomes exponentially localized around a certain moment in time. We here show that a three-dimensional system exposed to a properly disordered pseudoperiodic driving may display a localized-delocalized Anderson transition in the time domain, in strong analogy with the usual three-dimensional Anderson transition in disordered systems. Such a transition could be experimentally observed with ultracold atomic gases.
Preliminary investigations of protein crystal growth using the Space Shuttle
NASA Technical Reports Server (NTRS)
Delucas, L. J.; Suddath, F. L.; Snyder, R.; Naumann, R.; Broom, M. B.; Pusey, M.; Yost, V.; Herren, B .; Carter, D.
1986-01-01
Four preliminary Shuttle experiments are described which have been used to develop prototype hardware for a more advanced system that will evaluate effects of gravity on protein crystal growth. The first phase of these experiments has centered on the development of micromethods for protein crystal growth by vapor-diffusion techniques (using a space version of the hanging-drop method) and on dialysis using microdialysis cells. Results suggest that the elimination of density-driven sedimentation can effect crystal morphology. In the dialysis experiment, space-grown crystals of concanavalin B were three times longer and 1/3 the thickness of earth-grown crystals.
A physicist's view of biotechnology. [small molecule crystal growth in space
NASA Technical Reports Server (NTRS)
Kroes, Roger L.
1987-01-01
Theories and techniques for small molecule crystal growth are reviewed, with emphasis on space processing possibilities, particularly for protein crystal growth. The general principles of nucleation, growth, and mass and heat transport are first discussed. Optical systems using schlieren, shadowgraph, and holographic techniques are considered, and are illustrated with the example of the NASA developed Fluids Experiment System flow aboard Spacelab 3.
Producing gallium arsenide crystals in space
NASA Technical Reports Server (NTRS)
Randolph, R. L.
1984-01-01
The production of high quality crystals in space is a promising near-term application of microgravity processing. Gallium arsenide is the selected material for initial commercial production because of its inherent superior electronic properties, wide range of market applications, and broad base of on-going device development effort. Plausible product prices can absorb the high cost of space transportation for the initial flights provided by the Space Transportation System. The next step for bulk crystal growth, beyond the STS, is planned to come later with the use of free flyers or a space station, where real benefits are foreseen. The use of these vehicles, together with refinement and increasing automation of space-based crystal growth factories, will bring down costs and will support growing demands for high quality GaAs and other specialty electronic and electro-optical crystals grown in space.
Space manufacturing in an automated crystal growth facility
NASA Technical Reports Server (NTRS)
Quinn, Alberta W.; Herrmann, Melody C.; Nelson, Pamela J.
1989-01-01
An account is given of a Space Station Freedom-based robotic laboratory system for crystal growth experiments; the robot must interface with both the experimental apparatus and such human input as may be required for control and display. The goal of the system is the simultaneous growth of several hundred protein crystals in microgravity. The robot possesses six degrees-of-freedom, allowing it to efficiently manipulate the cultured crystals as well as their respective growth cells; the crystals produced are expected to be of sufficiently high quality for complete structural determination on the basis of XRD.
Holographic data storage crystals for the LDEF. [long duration exposure facility
NASA Technical Reports Server (NTRS)
Callen, W. Russell; Gaylord, Thomas K.
1992-01-01
Lithium niobate is a significant electro-optic material, with potential applications in ultra high capacity storage and processing systems. Lithium niobate is the material of choice for many integrated optical devices and holographic mass memory systems. For crystals of lithium niobate were passively exposed to the space environment of the Long Duration Exposure Facility (LDEF). Three of these crystals contained volume holograms. Although the crystals suffered the surface damage characteristics of most of the other optical components on the Georgia Tech tray, the crystals were recovered intact. The holograms were severely degraded because of the lengthy exposure, but the bulk properties are being investigated to determine the spaceworthiness for space data storage and retrieval systems.
Real-time processing of interferograms for monitoring protein crystal growth on the Space Station
NASA Technical Reports Server (NTRS)
Choudry, A.; Dupuis, N.
1988-01-01
The possibility of using microscopic interferometric techniques to monitor the growth of protein crystals on the Space Station is studied. Digital image processing techniques are used to develop a system for the real-time analysis of microscopic interferograms of nucleation sites during protein crystal growth. Features of the optical setup and the image processing system are discussed and experimental results are presented.
Reciprocal Space Mapping of Macromolecular Crystals in the Laboratory
NASA Technical Reports Server (NTRS)
Snell, Edward H.; Boggon, T. J.; Fewster, P. F.; Siddons, D. P.; Stojanof, V.; Pusey, M. L.
1998-01-01
The technique of reciprocal space mapping applied to the physical measurement of macromolecular crystals will be described. This technique uses a triple axis diffractometer setup whereby the monochromator is the first crystal, the sample is the second and the third crystal (of the same material as the monochromator) analyzes the diffracted beam. The geometry is such that it is possible to separate mosaic volume effects from lattice strain effects. The deconvolution of the instrument parameters will also be addressed. Results from measurements at Brookhaven National Synchrotron Radiation Source carried out on microgravity and ground-grown crystals will be presented. The required beam characteristics for reciprocal space mapping are also ideal for topographic studies and the first topographs ever recorded from microgravity protein crystal samples will be shown. We are now working on a system which will enable reciprocal space mapping, mosaicity and topography studies to be carried out in the home laboratory. This system uses a rotating anode X-ray source to provide an intense beam then a Bartels double crystal, four reflection monochromator to provide the spectral and geometric beam conditioning necessary such that the instrument characteristics do not mask the measurement. This is coupled to a high precision diffractometer and sensitive detector. Commissioning data and first results from the system will be presented.
Space processing of crystals for opto-electronic devices: The case for solution growth
NASA Technical Reports Server (NTRS)
Hayden, S. C.; Cross, L. E.
1975-01-01
The results obtained during a six month program aimed at determining the viability of space processing in the 1980's of dielectric-elastic-magnetic single crystals were described. The results of this program included: identification of some important emerging technologies dependent on dielectric-elastic-magnetic crystals, identification of the impact of intrinsic properties and defects in the single crystals on system performance, determination of a sensible common basis for the many crystals of this class, and identification of the benefits of micro-gravity and some initial experimental evidence that these benefits can be realized in space. It is concluded that advanced computers and optical communications are at a development stage for high demand of dielectric-elastic-magnetic single crystals in the mid-1980's. Their high unit cost and promise for significantly increased perfection by growth in space justified pursuit of space processing.
Protein crystal growth in microgravity
NASA Technical Reports Server (NTRS)
Rosenblum, William M.; Delucas, Lawrence J.; Wilson, William W.
1989-01-01
Major advances have been made in several of the experimental aspects of protein crystallography, leaving protein crystallization as one of the few remaining bottlenecks. As a result, it has become important that the science of protein crystal growth is better understood and that improved methods for protein crystallization are developed. Preliminary experiments with both small molecules and proteins indicate that microgravity may beneficially affect crystal growth. For this reason, a series of protein crystal growth experiments using the Space Shuttle was initiated. The preliminary space experiments were used to evolve prototype hardware that will form the basis for a more advanced system that can be used to evaluate effects of gravity on protein crystal growth. Various optical techniques are being utilized to monitor the crystal growth process from the incipient or nucleation stage and throughout the growth phase. The eventual goal of these studies is to develop a system which utilizes optical monitoring for dynamic control of the crystallization process.
Overview of materials processing in space activity at Marshall Space Flight Center
NASA Technical Reports Server (NTRS)
Williams, J. R.; Chassay, R. P.; Moore, W. W.; Ruff, R. C.; Yates, I. C.
1984-01-01
An overview of activities involving the Space Transportation System (STS), now in the operational phase, and results of some of the current space experiments, as well as future research opportunities in microgravity environment, are presented. The experiments of the Materials Processing in Space Program flown on the STS, such as bioseparation processes, isoelectric focusing, solidification and crystal growth processes, containerless processes, and the Materials Experiment Assembly experiments are discussed. Special consideration is given to the experiments to be flown aboard the Spacelab 3 module, the Fluids Experiments System, and the Vapor Crystal Growth System. Ground-based test facilities and planned space research facilities, as well as the nature of the commercialization activities, are briefly explained.
Astronaut Scott Parazynski works with PCG experiment on middeck
1994-11-14
STS066-13-029 (3-14 Nov 1994) --- On the Space Shuttle Atlantis' mid-deck, astronaut Scott E. Parazynski, mission specialist, works at one of two areas onboard the Shuttle which support the Protein Crystal Growth (PCG) experiment. This particular section is called the Vapor Diffusion Apparatus (VDA), housed in a Single Locker Thermal Enclosure (STES). Together with the Crystal Observation System, housed in the Thermal Enclosure System (COS/TES) the VDA represents the continuing research into the structures of proteins and other macromolecules such as viruses. In addition to using the microgravity of space to grow high-quality protein crystals for structural analyses, the experiments are expected to help develop technologies and methods to improve the protein crystallization process on Earth as well as in space.
Protein crystal growth in a microgravity environment
NASA Technical Reports Server (NTRS)
Bugg, Charles E.
1988-01-01
Protein crystal growth is a major experimental problem and is the bottleneck in widespread applications of protein crystallography. Research efforts now being pursued and sponsored by NASA are making fundamental contributions to the understanding of the science of protein crystal growth. Microgravity environments offer the possibility of performing new types of experiments that may produce a better understanding of protein crystal growth processes and may permit growth environments that are more favorable for obtaining high quality protein crystals. A series of protein crystal growth experiments using the space shuttle was initiated. The first phase of these experiments was focused on the development of micro-methods for protein crystal growth by vapor diffusion techniques, using a space version of the hanging drop method. The preliminary space experiments were used to evolve prototype hardware that will form the basis for a more advanced system that can be used to evaluate effects of gravity on protein crystal growth.
Quartz-like Crystals Found in Planetary Disks
2008-11-11
NASA Spitzer Space Telescope has, for the first time, detected tiny quartz-like crystals sprinkled in young planetary systems. The crystals, which are types of silica minerals called cristobalite and tridymite.
NASA Astrophysics Data System (ADS)
Moriguchi, Tetsuji; Yakeya, Daisuke; Tsuge, Akihiko; Jalli, Venkataprasad
2018-04-01
Three new thiophene condensed fluorescent pyrene derivatives have been synthesized by a two-step process, via. Wittig reaction followed by iodine promoted photocyclization. These molecules have been characterized by 1H NMR and EI-MS. Further, the molecular structures of 4a, 4b and 4c has been confirmed by single crystal X-ray diffraction analysis. The protons located in the fjord and cove-regions of molecules 4b and 4c showed downfield shifts of the protons. Molecule 4a crystallized under monoclinic system with space group P21/c, molecule 4b crystallized under monoclinic system with space group C2/c and the molecule 4c crystalized under triclinic system with space group P-1. Molecules 4a, 4b and 4c showed strong absorption maxima wavelengths at 305, 358 and 330 nm, respectively. The molar extinctinction coefficients (ε) of the compounds 4a, 4b and 4c indicated molecule 4c has better ability to absorb UV light, molecule 4b has better fluorescence intensity than molecule 4a and 4c.
Time Crystal Platform: From Quasicrystal Structures in Time to Systems with Exotic Interactions.
Giergiel, Krzysztof; Miroszewski, Artur; Sacha, Krzysztof
2018-04-06
Time crystals are quantum many-body systems that, due to interactions between particles, are able to spontaneously self-organize their motion in a periodic way in time by analogy with the formation of crystalline structures in space in condensed matter physics. In solid state physics properties of space crystals are often investigated with the help of external potentials that are spatially periodic and reflect various crystalline structures. A similar approach can be applied for time crystals, as periodically driven systems constitute counterparts of spatially periodic systems, but in the time domain. Here we show that condensed matter problems ranging from single particles in potentials of quasicrystal structure to many-body systems with exotic long-range interactions can be realized in the time domain with an appropriate periodic driving. Moreover, it is possible to create molecules where atoms are bound together due to destructive interference if the atomic scattering length is modulated in time.
Time Crystal Platform: From Quasicrystal Structures in Time to Systems with Exotic Interactions
NASA Astrophysics Data System (ADS)
Giergiel, Krzysztof; Miroszewski, Artur; Sacha, Krzysztof
2018-04-01
Time crystals are quantum many-body systems that, due to interactions between particles, are able to spontaneously self-organize their motion in a periodic way in time by analogy with the formation of crystalline structures in space in condensed matter physics. In solid state physics properties of space crystals are often investigated with the help of external potentials that are spatially periodic and reflect various crystalline structures. A similar approach can be applied for time crystals, as periodically driven systems constitute counterparts of spatially periodic systems, but in the time domain. Here we show that condensed matter problems ranging from single particles in potentials of quasicrystal structure to many-body systems with exotic long-range interactions can be realized in the time domain with an appropriate periodic driving. Moreover, it is possible to create molecules where atoms are bound together due to destructive interference if the atomic scattering length is modulated in time.
NASA Astrophysics Data System (ADS)
Deleer, B. G. M.
1981-11-01
Based on population balance, CSD behavior as a function of geometrical and operating variables was studied, using a crystallizer. A potash alum-water system, involving a separation technique which uses surface active agents and an apolar, organic liquid to separate potash alum crystals from mother liquid under the influence of gravity was used to check experimental findings against literature data. Results show action of annular settling spaces is strongly influenced by fluid velocities perpendicular to those directed upwards. The well-mixed volume decreases with increasing crystallizer size until a minimum effective volume is reached. As supersaturation is constant throughout the crystallizer volume under stationary operating conditions, the annular settling space behaves like a growth chamber for crystals in its volume. Swirl in the lower part of the annular volume introduces significant back mixing. Crystals within this space either grow and return to the well-mixed part, or withdraw from the annular volume permanently.
Astronaut Jan Davis monitors Commercial Protein Crystal Growth experiment
1994-02-03
STS060-21-031 (3-11 Feb 1994) --- Using a lap top computer, astronaut N. Jan Davis monitors systems for the Commercial Protein Crystal Growth (CPCG) experiment onboard the Space Shuttle Discovery. Davis joined four other NASA astronauts and a Russian cosmonaut for eight days in space aboard Discovery.
Crystal growth from the vapor phase experiment MA-085
NASA Technical Reports Server (NTRS)
Wiedemeir, H.; Sadeek, H.; Klaessig, F. C.; Norek, M.
1976-01-01
Three vapor transport experiments on multicomponent systems were performed during the Apollo Soyuz mission to determine the effects of microgravity forces on crystal morphology and mass transport rates. The mixed systems used germanium selenide, tellurium, germanium tetraiodide (transport agent), germanium monosulfide, germanium tetrachloride (transport agent), and argon (inert atmosphere). The materials were enclosed in evacuated sealed ampoules of fused silica and were transported in a temperature gradient of the multipurpose electric furnace onboard the Apollo Soyuz spacecraft. Preliminary evaluation of 2 systems shows improved quality of space grown crystals in terms of growth morphology and bulk perfection. This conclusion is based on a direct comparison of space grown and ground based crystals by means of X-ray diffraction, microscopic, and chemical etching techniques. The observation of greater mass transport rates than predicted for a microgravity environment by existing vapor transport models indicates the existence of nongravity caused transport effects in a reactive solid/gas phase system.
Mohamad Aris, Sayangku Nor Ariati; Thean Chor, Adam Leow; Mohamad Ali, Mohd Shukuri; Basri, Mahiran; Salleh, Abu Bakar; Raja Abd Rahman, Raja Noor Zaliha
2014-01-01
Three-dimensional structure of thermostable lipase is much sought after nowadays as it is important for industrial application mainly found in the food, detergent, and pharmaceutical sectors. Crystallization utilizing the counter diffusion method in space was performed with the aim to obtain high resolution diffracting crystals with better internal order to improve the accuracy of the structure. Thermostable T1 lipase enzyme has been crystallized in laboratory on earth and also under microgravity condition aboard Progress spacecraft to the ISS in collaboration with JAXA (Japanese Aerospace Exploration Agency). This study is conducted with the aims of improving crystal packing and structure resolution. The diffraction data set for ground grown crystal was collected to 1.3 Å resolution and belonged to monoclinic C2 space group with unit cell parameters a = 117.40 Å, b = 80.95 Å, and c = 99.81 Å, whereas the diffraction data set for space grown crystal was collected to 1.1 Å resolution and belonged to monoclinic C2 space group with unit cell parameters a = 117.31 Å, b = 80.85 Å, and c = 99.81 Å. The major difference between the two crystal growth systems is the lack of convection and sedimentation in microgravity environment resulted in the growth of much higher quality crystals of T1 lipase.
Holographic data storage crystals for LDEF (A0044)
NASA Technical Reports Server (NTRS)
Callen, W. R.; Gaylord, T. K.
1984-01-01
Electro-optic holographic recording systems were developed. The spaceworthiness of electro-optic crystals for use in ultrahigh capacity space data storage and retrieval systems are examined. The crystals for this experiment are included with the various electro-optical components of LDEF experiment. The effects of long-duration exposure on active optical system components is investigated. The concept of data storage in an optical-phase holographic memory is illustrated.
Classification of crystal structure using a convolutional neural network
Park, Woon Bae; Chung, Jiyong; Sohn, Keemin; Pyo, Myoungho
2017-01-01
A deep machine-learning technique based on a convolutional neural network (CNN) is introduced. It has been used for the classification of powder X-ray diffraction (XRD) patterns in terms of crystal system, extinction group and space group. About 150 000 powder XRD patterns were collected and used as input for the CNN with no handcrafted engineering involved, and thereby an appropriate CNN architecture was obtained that allowed determination of the crystal system, extinction group and space group. In sharp contrast with the traditional use of powder XRD pattern analysis, the CNN never treats powder XRD patterns as a deconvoluted and discrete peak position or as intensity data, but instead the XRD patterns are regarded as nothing but a pattern similar to a picture. The CNN interprets features that humans cannot recognize in a powder XRD pattern. As a result, accuracy levels of 81.14, 83.83 and 94.99% were achieved for the space-group, extinction-group and crystal-system classifications, respectively. The well trained CNN was then used for symmetry identification of unknown novel inorganic compounds. PMID:28875035
Classification of crystal structure using a convolutional neural network.
Park, Woon Bae; Chung, Jiyong; Jung, Jaeyoung; Sohn, Keemin; Singh, Satendra Pal; Pyo, Myoungho; Shin, Namsoo; Sohn, Kee-Sun
2017-07-01
A deep machine-learning technique based on a convolutional neural network (CNN) is introduced. It has been used for the classification of powder X-ray diffraction (XRD) patterns in terms of crystal system, extinction group and space group. About 150 000 powder XRD patterns were collected and used as input for the CNN with no handcrafted engineering involved, and thereby an appropriate CNN architecture was obtained that allowed determination of the crystal system, extinction group and space group. In sharp contrast with the traditional use of powder XRD pattern analysis, the CNN never treats powder XRD patterns as a deconvoluted and discrete peak position or as intensity data, but instead the XRD patterns are regarded as nothing but a pattern similar to a picture. The CNN interprets features that humans cannot recognize in a powder XRD pattern. As a result, accuracy levels of 81.14, 83.83 and 94.99% were achieved for the space-group, extinction-group and crystal-system classifications, respectively. The well trained CNN was then used for symmetry identification of unknown novel inorganic compounds.
NASA Astrophysics Data System (ADS)
Liu, Qiao
2015-06-01
In recent paper [7], Y. Du and K. Wang (2013) proved that the global-in-time Koch-Tataru type solution (u, d) to the n-dimensional incompressible nematic liquid crystal flow with small initial data (u0, d0) in BMO-1 × BMO has arbitrary space-time derivative estimates in the so-called Koch-Tataru space norms. The purpose of this paper is to show that the Koch-Tataru type solution satisfies the decay estimates for any space-time derivative involving some borderline Besov space norms.
NASA Technical Reports Server (NTRS)
Workman, Gary L.; Cummings, Rick; Jones, Brian
1992-01-01
The microgravity materials processing program has been instrumental in providing the crystal growth community with an experimental environment to better understand the phenomena associated with the growing of crystals. In many applications one may pursue the growth of large single crystals which cannot be grown on earth due to convective driven flows. A microgravity environment is characterized by neither convection of buoyancy. Consequently superior crystals are able to be grown in space. On the other hand, since neither convection nor buoyancy dominates the fluid flow in a microgravity environment, then lesser dominating phenomena can affect crystal growth, such as surface driven flows or diffusion limited solidification. In the case of experiments that are to be flown in space using the Fluid Experiments System (FES), diffusion limited growth should be the dominating phenomenon. The use of holographic and Schlieren optical techniques for studying the concentration gradients in solidification processes has been used by several investigators over the years. The Holographic Ground System (HGS) facility at MSFC has been a primary resource in researching this capability. Consequently scientific personnel have been able to utilize these techniques in both ground based research and in space experiments. An important event in the scientific utilization of the HGS facilities was the TGS (triglycine sulfate) Crystal Growth and the Casting and Solidification Technology (CAST) experiments that were flown on the International Microgravity Lab (IML) mission in March of this year. The preparation and processing of these space observations are the primary experiments reported in this work. This project provides some ground-based studies to optimize on the holographic techniques used to acquire information about the crystal growth processes flown on IML. Since the ground-based studies will be compared with the space-based experimental results, it is necessary to conduct sufficient ground based studies to best determine how the experiment in space worked. The current capabilities in computer based systems for image processing and numerical computation have certainly assisted in those efforts. As anticipated, this study has certainly shown that these advanced computing capabilities are helpful in the data analysis of such experiments.
Astronauts Lodewijk van den Berg observes growth of crystals in VCGS
1985-04-30
51B-06-010 (29 April-6 May 1985) --- Lodewijk van den Berg, 51-B payload specialist, observes the growth of mercuric iodide crystal in the vapor crystal growth system (VCGS) on the Spacelab 3 science module aboard the Space Shuttle Challenger.
NASA Astrophysics Data System (ADS)
Sharma, Abhiraj; Suryanarayana, Phanish
2018-05-01
We present an accurate and efficient real-space Density Functional Theory (DFT) framework for the ab initio study of non-orthogonal crystal systems. Specifically, employing a local reformulation of the electrostatics, we develop a novel Kronecker product formulation of the real-space kinetic energy operator that significantly reduces the number of operations associated with the Laplacian-vector multiplication, the dominant cost in practical computations. In particular, we reduce the scaling with respect to finite-difference order from quadratic to linear, thereby significantly bridging the gap in computational cost between non-orthogonal and orthogonal systems. We verify the accuracy and efficiency of the proposed methodology through selected examples.
NASA Astrophysics Data System (ADS)
Njogu, Eric M.; Nyamori, Vincent O.; Omondi, Bernard
2018-02-01
The occurrence of concomitant polymorphism in 4‧-(isoquinolyl)-2,2‧:6‧,2″-terpyridine, 1a and 1b (2-quinterpy) and conformational polymorphism in 4‧-(4-quinolyl)-2,2‧:6‧,2″-terpyridine (4-quinterpy) has been identified to due to crystallization process and solvent, respectively. Crystallization of 2-quinterpy in acetone yielded the concomitant polymorphs 1a and 1b which crystallize in the monoclinic P21/c and the orthorhombic Pna21 space groups, respectively. The polymorph 2a was grown from bulk 4-quinterpy in dimethyl sulfoxide, crystallizes in the monoclinic P21/c space group, while 2b grown from acetonitrile or even acetone crystallizes in the monoclinic system but in P21/n space group.
Zeng, Lunwu; Xu, Jin; Wang, Chengen; Zhang, Jianhua; Zhao, Yuting; Zeng, Jing; Song, Runxia
2017-12-07
When space (time) translation symmetry is spontaneously broken, the space crystal (time crystal) forms; when permittivity and permeability periodically vary with space (time), the photonic crystal (photonic time crystal) forms. We proposed the concept of photonic time crystal and rewritten the Maxwell's equations. Utilizing Finite Difference Time Domain (FDTD) method, we simulated electromagnetic wave propagation in photonic time crystal and photonic space-time crystal, the simulation results show that more intensive scatter fields can obtained in photonic time crystal and photonic space-time crystal.
Time Crystal Behavior of Excited Eigenstates
NASA Astrophysics Data System (ADS)
Syrwid, Andrzej; Zakrzewski, Jakub; Sacha, Krzysztof
2017-12-01
In analogy to spontaneous breaking of continuous space translation symmetry in the process of space crystal formation, it was proposed that spontaneous breaking of continuous time translation symmetry could lead to time crystal formation. In other words, a time-independent system prepared in the energy ground state is expected to reveal periodic motion under infinitely weak perturbation. In the case of the system proposed originally by Wilczek, spontaneous breaking of time translation symmetry cannot be observed if one starts with the ground state. We point out that the symmetry breaking can take place if the system is prepared in an excited eigenstate. The latter can be realized experimentally in ultracold atomic gases. We simulate the process of the spontaneous symmetry breaking due to measurements of particle positions and analyze the lifetime of the resulting symmetry broken state.
Time Crystal Behavior of Excited Eigenstates.
Syrwid, Andrzej; Zakrzewski, Jakub; Sacha, Krzysztof
2017-12-22
In analogy to spontaneous breaking of continuous space translation symmetry in the process of space crystal formation, it was proposed that spontaneous breaking of continuous time translation symmetry could lead to time crystal formation. In other words, a time-independent system prepared in the energy ground state is expected to reveal periodic motion under infinitely weak perturbation. In the case of the system proposed originally by Wilczek, spontaneous breaking of time translation symmetry cannot be observed if one starts with the ground state. We point out that the symmetry breaking can take place if the system is prepared in an excited eigenstate. The latter can be realized experimentally in ultracold atomic gases. We simulate the process of the spontaneous symmetry breaking due to measurements of particle positions and analyze the lifetime of the resulting symmetry broken state.
Solid-state reaction kinetics of neodymium doped magnesium hydrogen phosphate system
NASA Astrophysics Data System (ADS)
Gupta, Rashmi; Slathia, Goldy; Bamzai, K. K.
2018-05-01
Neodymium doped magnesium hydrogen phosphate (NdMHP) crystals were grown by using gel encapsulation technique. Structural characterization of the grown crystals has been carried out by single crystal X-ray diffraction (XRD) and it revealed that NdMHP crystals crystallize in orthorhombic crystal system with space group Pbca. Kinetics of the decomposition of the grown crystals has been studied by non-isothermal analysis. The estimation of decomposition temperatures and weight loss has been made from the thermogravimetric/differential thermo analytical (TG/DTA) in conjuncture with DSC studies. The various steps involved in the thermal decomposition of the material have been analysed using Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova equations for evaluating various kinetic parameters.
NASA Astrophysics Data System (ADS)
Liu, Tuo; Zhu, Xuefeng; Chen, Fei; Liang, Shanjun; Zhu, Jie
2018-03-01
Exploring the concept of non-Hermitian Hamiltonians respecting parity-time symmetry with classical wave systems is of great interest as it enables the experimental investigation of parity-time-symmetric systems through the quantum-classical analogue. Here, we demonstrate unidirectional wave vector manipulation in two-dimensional space, with an all passive acoustic parity-time-symmetric metamaterials crystal. The metamaterials crystal is constructed through interleaving groove- and holey-structured acoustic metamaterials to provide an intrinsic parity-time-symmetric potential that is two-dimensionally extended and curved, which allows the flexible manipulation of unpaired wave vectors. At the transition point from the unbroken to broken parity-time symmetry phase, the unidirectional sound focusing effect (along with reflectionless acoustic transparency in the opposite direction) is experimentally realized over the spectrum. This demonstration confirms the capability of passive acoustic systems to carry the experimental studies on general parity-time symmetry physics and further reveals the unique functionalities enabled by the judiciously tailored unidirectional wave vectors in space.
A Fiber Optic Probe for Monitoring Protein Aggregation, Nucleation, and Crystallization
NASA Technical Reports Server (NTRS)
Ansari, Rafat R.; Suh, Kwang I.; Arabshahi, Alireza; Wilson, William W.; Bray, Terry L.; DeLucas, Lawrence J.
1996-01-01
Protein crystals are experimentally grown in hanging drops in microgravity experiments on-board the Space Shuttle orbiter. The technique of dynamic light scattering (DLS) can be used to monitor crystal growth process in hanging droplets (approx. 30 (L)) in microgravity experiments, but elaborate instrumentation and optical alignment problems have made in-situ applications difficult. In this paper we demonstrate that such experiments are now feasible. We apply a newly developed fiber optic probe to various earth and space (micro- gravity) bound protein crystallization system configurations to test its capability. These include conventional batch (cuvette or capillary) systems, hanging drop method in a six-pack hanging drop vapor diffusion apparatus (HDVDA), a modified HDVDA for temperature- induced nucleation and aggregation studies, and a newly envisioned dynamically controlled vapor diffusion system (DCVDS) configuration. Our compact system exploits the principles of DLS and offers a fast (within a few seconds) means of quantitatively and non-invasively monitoring the various growth stages of protein crystallization. In addition to DLS capability, the probe can also be used for performing single-angle static light scattering measurements. It utilizes extremely low levels of laser power (approx. few (W)) without a need of having any optical alignment and vibration isolation. The compact probe is also equipped with a miniaturized microscope for visualization of macroscopic protein crystals. This new optical diagnostic system opens up enormous opportunity for exploring new ways to grow good quality crystals suitable for x-ray crystallographic analysis and may help develop a concrete scientific basis for understanding the process of crystallization.
Astronauts Brent Jett and Koichi Wakata work with Protein Crystal Growth experiment
1996-01-20
STS072-310-007 (11-20 Jan. 1996) --- Astronauts Brent W. Jett Jr. (left) and Koichi Wakata work with the Protein Crystal Growth (PCG) experiment at the Single Locker Thermal Enclosure System (STES) on the Space Shuttle Endeavour’s mid-deck. Jett, making his first flight in space, served as the crew’s pilot, while Wakata served as a mission specialist. Wakata, also a first time Shuttle crew member, represents Japan’s National Space Development Agency (NASDA).
ICESat-2 laser Nd:YVO4 amplifier
NASA Astrophysics Data System (ADS)
Sawruk, Nicholas W.; Burns, Patrick M.; Edwards, Ryan E.; Litvinovitch, Viatcheslav; Martin, Nigel; Witt, Greg; Fakhoury, Elias; Iskander, John; Pronko, Mark S.; Troupaki, Elisavet; Bay, Michael M.; He, Charles C.; Wang, Liqin L.; Cavanaugh, John F.; Farrokh, Babak; Salem, Jonathan A.; Baker, Eric
2018-02-01
We report on the cause and corrective actions of three amplifier crystal fractures in the space-qualified laser systems used in NASA Goddard Space Flight Center's (GSFC) Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2). The ICESat-2 lasers each contain three end-pumped Nd:YVOO4 amplifier stages. The crystals are clamped between two gold plated copper heat spreaders with an indium foil thermal interface material, and the crystal fractures occurred after multiple years of storage and over a year of operational run-time. The primary contributors are high compressive loading of the NdYVO4 crystals at the beginning of life, a time dependent crystal stress caused by an intermetallic reaction of the gold plating and indium, and slow crack growth resulting in a reduction in crystal strength over time. An updated crystal mounting scheme was designed, analyzed, fabricated and tested. Thee fracture slab failure analysis, finite-element modeling and corrective actions are presented.
NASA Astrophysics Data System (ADS)
Zhu, D.-W.; Han, Q.; Qiu, W.; Campbell, R. L.; Xie, B.-X.; Azzi, A.; Lin, S.-X.
1999-01-01
Human estrogenic 17β-hydroxysteroid dehydrogenase (17β-HSD1) is responsible for the synthesis of active estrogens that stimulate the proliferation of breast cancer cells. The enzyme has been crystallized using a Mg 2+/PEG (3500)/β-octyl glucoside system [Zhu et al., J. Mol. Biol. 234 (1993) 242]. The space group of these crystals is C2. Here we report that cations can affect 17β-HSD1 crystallization significantly. In the presence of Mn 2+ instead of Mg 2+, crystals have been obtained in the same space group with similar unit cell dimensions. In the presence of Li + and Na + instead of Mg 2+, the space group has been changed to P2 12 12 1. A whole data set for a crystal of 17ß-HSD1 complex with progesterone grown in the presence of Li + has been collected to 1.95 Å resolution with a synchrotron source. The cell dimensions are a=41.91 Å, b=108.21 Å, c=117.00 Å. The structure has been preliminarily determined by molecular replacement, yielding important information on crystal packing in the presence of different cations. In order to further understand the structure-function relationship of 17β-HSD1, enzyme complexes with several ligands have been crystallized. As the steroids have very low aqueous solubility, we used a combined method of seeding and co-crystallization to obtain crystals of 17β-HSD1 complexed with various ligands. This method provides ideal conditions for growing complex crystals, with ligands such as 20α-hydroxysteroid progesterone, testosterone and 17β-methyl-estradiol-NADP +. Several complex structures have been determined with reliable electronic density of the bound ligands.
Crystallization of Ulex europaeus lectin I.
Vandonselaar, M; Delbaere, L T
1994-10-21
The lectin I from Ulex europaeus (UEAI) has a strong affinity for the H-type 2 human blood group determinant. Single crystals of UEAI have been grown in the monoclinic crystal system. Initial crystals were obtained after 11 months from a solution of 10 mg/ml protein, 40% 2,4-methylpentanediol and 0.1 N acetate buffer at pH 5.2. The technique of washing and reseeding was used to generate large suitable crystals. The space group is C2 with a = 78.84 A, b = 69.85 A, c = 120.62 A, beta = 108.74 degrees and Z = 4; there is one molecular dimer per asymmetric unit and the solvent content is estimated to be 58%. The crystals diffract to at least 2.8 A d spacings and are stable in the X-ray beam for more than three days.
Precision Laser Development for Interferometric Space Missions NGO, SGO, and GRACE Follow-On
NASA Technical Reports Server (NTRS)
Numata, Kenji; Camp, Jordan
2011-01-01
Optical fiber and semiconductor laser technologies have evolved dramatically over the last decade due to the increased demands from optical communications. We are developing a laser (master oscillator) and optical amplifier based on those technologies for interferometric space missions, including the gravitational-wave missions NGO/SGO (formerly LISA) and the climate monitoring mission GRACE Follow-On, by fully utilizing the matured wave-guided optics technologies. In space, where simpler and more reliable system is preferred, the wave-guided components are advantageous over bulk, crystal-based, free-space laser, such as NPRO (Nonplanar Ring Oscillator) and bulk-crystal amplifier.
Imaging System For Measuring Macromolecule Crystal Growth Rates in Microgravity
NASA Technical Reports Server (NTRS)
Corder, Eric L.; Briscoe, Jeri
2004-01-01
In order to determine how macromolecule crystal quality improvement in microgravity is related to crystal growth characteristics, a team of scientists and engineers at NASA's Marshal Space Flight Center (MSFC) developed flight hardware capable of measuring the crystal growth rates of a population of crystals growing under the same conditions. As crystal growth rate is defined as the change or delta in a defined dimension or length (L) of crystal over time, the hardware was named Delta-L. Delta-L consists of three sub assemblies: a fluid unit including a temperature-controlled growth cell, an imaging unit, and a control unit (consisting of a Data Acquisition and Control Unit (DACU), and a thermal control unit). Delta-L will be used in connection with the Glovebox Integrated Microgravity Isolation Technology (g-LIMIT) inside the Microgravity Science Glovebox (MSG), onboard the International Space Station. This paper will describe the Delta-L imaging system. The Delta-L imaging system was designed to locate, resolve, and capture images of up to 10 individual crystals ranging in size from 10 to 500 microns with a point-to-point accuracy of +/- 2.0 microns within a quartz growth cell observation area of 20 mm x 10 mm x 1 mm. The optical imaging system is comprised of a video microscope camera mounted on computer controlled translation stages. The 3-axis translation stages and control units provide crewmembers the ability to search throughout the growth cell observation area for crystals forming in size of approximately 10 microns. Once the crewmember has selected ten crystals of interest, the growth of these crystals is tracked until the size reaches approximately 500 microns. In order to resolve these crystals an optical system with a magnification of 10X was designed. A black and white NTSC camera was utilized with a 20X microscope objective and a 0.5X custom designed relay lens with an inline light to meet the magnification requirement. The design allows a 500 pm crystal to be viewed in the vertical dimension on a standard NTSC monitor (4:3 aspect ratio). Images of the 10 crystals are collected periodically and stored in sets by the DACU.
NASA Technical Reports Server (NTRS)
Larsen, D. C.; Sievert, J. L.
1975-01-01
The potential of producing the glassy form of selected materials in the weightless, containerless nature of space processing is examined through the development of kinetic relationships describing nucleation and crystallization phenomena. Transformation kinetics are applied to a well-characterized system (SiO2), an excellent glass former (B2O3), and a poor glass former (Al2O3) by conventional earth processing methods. Viscosity and entropy of fusion are shown to be the primary materials parameters controlling the glass forming tendency. For multicomponent systems diffusion-controlled kinetics and heterogeneous nucleation effects are considered. An analytical empirical approach is used to analyze the mullite system. Results are consistent with experimentally observed data and indicate the promise of mullite as a future space processing candidate.
NASA Astrophysics Data System (ADS)
Suresh Kumar, G. S.; Seethalakshmi, P. G.; Bhuvanesh, N.; Kumaresan, S.
2013-02-01
Three organic cocrystals namely, caffeine:p-formylphenoxyacetic acid [(caf)(p-fpaa)] (1) caffeine:o-formylphenoxyacetic acid monohydrate [(caf)(o-fpaa)]H2O (2) and caffeine:p-formylphenoxypropionic acid [(caf)(p-fppa)] (3) were synthesized and studied by FT-IR, NMR, and single crystal XRD studies. The crystal system of cocrystal [(caf)(p-fpaa)] (1) is monoclinic with space group P21/n and Z = 16, that of cocrystal [(caf)(o-fpaa)]H2O (2) is triclinic with space group P - 1 and Z = 2, and that of cocrystal [(caf)(p-fppa)] (3) is monoclinic with space group P21/c and Z = 4. The imidazole-carboxylic acid synthon is observed in all the three cocrystals. The intermolecular hydrogen bonds, Osbnd H···N and π-π interactions together play a major role in stabilizing the crystal structure of all the three cocrystals. The biological activities of crystals 1-3 were studied.
NASA Technical Reports Server (NTRS)
Li, C.
1975-01-01
Computer programs are developed and used in the study of the combined effects of evaporation and solidification in space processing. The temperature and solute concentration profiles during directional solidification of binary alloys with surface evaporation were mathematically formulated. Computer results are included along with an econotechnical model of crystal growth. This model allows: prediction of crystal size, quality, and cost; systematic selection of the best growth equipment or alloy system; optimization of growth or material parameters; and a maximization of zero-gravity effects. Segregation in GaAs crystals was examined along with vibration effects on GaAs crystal growth. It was found that a unique segregation pattern and strong convention currents exist in GaAs crystal growth. Some beneficial effects from vibration during GaAs growth were discovered. The implications of the results in space processing are indicated.
Noise and Dynamical Pattern Selection in Solidification
NASA Technical Reports Server (NTRS)
Kurtze, Douglas A.
1997-01-01
The overall goal of this project was to understand in more detail how a pattern-forming system can adjust its spacing. "Pattern-forming systems," in this context, are nonequilibrium contina whose state is determined by experimentally adjustable control parameter. Below some critical value of the control system then has available to it a range of linearly stable, spatially periodic steady states, each characterized by a spacing which can lie anywhere within some band of values. These systems like directional solidification, where the solidification front is planar when the ratio of growth velocity to thermal gradient is below its critical value, but takes on a cellular shape above critical. They also include systems without interfaces, such as Benard convection, where it is the fluid velocity field which changes from zero to something spatially periodic as the control parameter is increased through its critical value. The basic question to be addressed was that of how the system chooses one of its myriad possible spacings when the control parameter is above critical, and in particular the role of noise in the selection process. Previous work on explosive crystallization had suggested that one spacing in the range should be preferred, in the sense that weak noise should eventually drive the system to that spacing. That work had also suggested a heuristic argument for identifying the preferred spacing. The project had three main objectives: to understand in more detail how a pattern-forming system can adjust its spacing; to investigate how noise drives a system to its preferred spacing; and to extend the heuristic argument for a preferred spacing in explosive crystallization to other pattern-forming systems.
NASA Technical Reports Server (NTRS)
Rogers, Melissa J. B.; Alexander, J. I. D.; Schoess, Jeff
1993-01-01
The Honeywell In-Space Accelerometer (HISA) system collected data in the mid-deck area of the Shuttle Columbia during the flight of STS-32, January 1990. The resulting data were to be used to investigate the response of crystal microstructure to different types of residual acceleration. The HISA is designed to detect and record transient and oscillatory accelerations. The sampling and electronics package stored averaged accelerations over two sampling periods; two sampling rates were available: 1 Hz and 50 Hz. Analysis of the HISA data followed the CMMR Acceleration Data Processing Guide, considering in-house computer modelling of a float-zone indium crystal growth experiment. Characteristic examples of HISA data showing the response to the primary reaction control system, Orbiter Maneuvering System operations, and crew treadmill activity are presented. Various orbiter structural modes are excited by these and other activities.
Protein Crystal Growth (PCG) experiment aboard mission STS-66
NASA Technical Reports Server (NTRS)
2000-01-01
On the Space Shuttle Orbiter Atlantis' middeck, Astronaut Joseph R. Tarner, mission specialist, works at an area amidst several lockers which support the Protein Crystal Growth (PCG) experiment during the STS-66 mission. This particular section is called the Crystal Observation System, housed in the Thermal Enclosure System (COS/TES). Together with the Vapor Diffusion Apparatus (VDA), housed in Single Locker Thermal Enclosure (SLTES), the COS/TES represents the continuing research into the structure of proteins and other macromolecules such as viruses.
Precision Laser Development for Gravitational Wave Space Mission
NASA Technical Reports Server (NTRS)
Numata, Kenji; Camp, Jordan
2011-01-01
Optical fiber and semiconductor laser technologies have evolved dramatically over the last decade due to the increased demands from optical communications. We are developing a laser (master oscillator) and optical amplifier based on those technologies for interferometric space missions, such as the gravitational-wave mission LISA, and GRACE follow-on, by fully utilizing the mature wave-guided optics technologies. In space, where a simple and reliable system is preferred, the wave-guided components are advantageous over bulk, crystal-based, free-space laser, such as NPRO (Non-planar Ring Oscillator) and bulk-crystal amplifier, which are widely used for sensitive laser applications on the ground.
Crystallization and preliminary X-ray analysis of copper amine oxidase from Escherichia coli K-12.
Roh, J H; Suzuki, H; Kumagai, H; Yamashita, M; Azakami, H; Murooka, Y; Mikami, B
1994-05-13
Copper-containing monoamine oxidase (MAO) from Escherichia coli was overproduced in the periplasmic space by expression of the cloned gene. The purified MAO has been crystallized by means of the hanging drop technique using sodium citrate as a precipitant. The crystals belong to the orthorhombic system, space group P2(1)2(1)2(1), with unit cell dimensions of a = 136.1 A, b = 168.4 A and c = 81.6 A. The asymmetric unit contains one molecule of MAO, with a crystal volume per protein mass (Vm) of 2.88 A3/Da and a solvent content of 58% by volume. The crystals diffract X-rays to a resolution limit of at least 2.7 A and are resistant to X-ray radiation damage. They appear to be suitable for X-ray structure analysis.
Double Diffusive Convection in Materials Processing
NASA Technical Reports Server (NTRS)
Ramachandra, Narayanan; Leslie, Fred W.
1999-01-01
A great number of crystals grown in space are plagued by convective motions which contribute to structural flaws. The character of these instabilities is not well understood but is associated with density variations in the presence of residual gravity (g-jitter). As a specific example, past HgCdTe crystal growth space experiments by Lehoczky and co-workers indicate radial compositional asymmetry in the grown crystals. In the case of HgCdTe the rejected component into the melt upon solidification is HgTe which is denser than the melt. The space grown crystals indicate the presence of three dimensional flow with the heavier HgTe-rich material clearly aligned with the residual gravity (0.55-1.55 micro g) vector. This flow stems from double-diffusive convection, namely, thermal and solutal buoyancy driven flow in the melt. The study of double-diffusive convection is multi-faceted and rather vast. In our investigation, we seek to focus on one specific aspect of this discipline that is of direct relevance to materials processing especially crystal growth, namely, the side ways heating regime. This problem has been widely studied, both experimentally and numerically, in the context of solar ponds wherein the system is characterized by a linear salt (solutal) gradient with an imposed lateral temperature gradient. The induced flow instabilities arise from the wide disparity between the fluid thermal diffusivity and the solute diffusivity. The extension of the analysis to practical crystal growth applications has however not been rigorously made and understood. One subtle but important difference in crystal growth systems is the fact that die system solute gradient is non-linear (typically exponential). Besides, the crystal growth problem has the added complexities of solidification, both lateral and longitudinal thermal gradients and segregation phenomena in systems where binary and ternary compounds are being grown. This paper treats the side ways heating problem alone in a model fluid system. Results from detailed numerical calculations, mainly two dimensional are provided. The interactions between a non-linear solute gradient and an imposed transverse thermal gradient are investigated. The buoyancy effects are treated in the traditional Boussinesq approximation and also in a more complete density formulation to address recent concerns of the first approach especially in simulations of the system response in a reduced gravity environment. Detailed flow, temperature and solute field plots along with heat and mass transfer results are presented in the paper. Implications to practical crystal growth systems as discerned from the modeling results are also explored and reported.
Update on the NASA Glenn Propulsion Systems Lab Ice Crystal Cloud Characterization (2015, 2016)
NASA Technical Reports Server (NTRS)
Van Zante, Judith; Bencic, Timothy; Ratvasky, Thomas
2016-01-01
NASA Glenn's Propulsion Systems Lab, an altitude engine test facility, was outfitted with a spray system to generate ice crystals in 2011. Turbine engines and driven rigs can experience ice crystal icing at flight altitudes, temperatures and Mach numbers. To support these tests, four ice crystal characterizations have been conducted in two different facility configurations. In addition, super-cooled liquid and mixed phase clouds have also been generated. This paper represents a work in progress. It will describe some of the 11-parameter calibration space, and how those parameters interact with each other, the instrumentation used to characterize the cloud and present a sample of the cloud characterization results.
A low temperature furnace for solution crystal growth on the International Space Station
NASA Astrophysics Data System (ADS)
Baç, Nurcan; Harpster, Joseph; Maston, Robert A.; Sacco, Albert
2000-01-01
The Zeolite Crystal Growth Furnace Unit (ZCG-FU) is the first module in an integrated payload designed for low temperature crystal growth in solutions on the International Space Station (ISS). This payload is scheduled to fly on the ISS flight 7A.1 in an EXPRESS rack. Its name originated from early shuttle flight experiments limited to the growth of zeolite crystals but has since grown to include other materials of significant commercial interest using the solution method of crystal growth. Zeolites, ferroelectrics, piezeoelectrics and silver halides are some of the materials considered. The ZCG-FU experiment consists of a furnace unit and its electronic control system, and mechanically complex, crystal growth autoclaves suitable for use with a particular furnace and solution. The ZCG facility is being designed to grow into four independent furnaces controlled by IZECS (Improved Zeolite Electronic Control System). IZECS provides monitoring of critical parameters, data logging, safety monitoring, air-to-ground control and operator interfacing. It is suitable for controlling the four furnaces either individually or all at one time. It also contains the power management solid-state drivers and switches for the ZCG-FU furnace. The furnace contains 19 tubes operating at three different temperature zones. .
1992-01-01
International Microgravity Laboratory-1 (IML-1) was the first in a series of Shuttle flights dedicated to fundamental materials and life sciences research with the international partners. The participating space agencies included: NASA, the 14-nation European Space Agency (ESA), the Canadian Space Agency (CSA), the French National Center of Space Studies (CNES), the German Space Agency and the German Aerospace Research Establishment (DAR/DLR), and the National Space Development Agency of Japan (NASDA). Dedicated to the study of life and materials sciences in microgravity, the IML missions explored how life forms adapt to weightlessness and investigated how materials behave when processed in space. Both life and materials sciences benefited from the extended periods of microgravity available inside the Spacelab science module in the cargo bay of the Space Shuttle Orbiter. In this photograph, Astronauts Stephen S. Oswald and Norman E. Thagard handle ampoules used in the Mercuric Iodide Crystal Growth (MICG) experiment. Mercury Iodide crystals have practical uses as sensitive x-ray and gamma-ray detectors. In addition to their exceptional electronic properties, these crystals can operate at room temperature rather than at the extremely low temperatures usually required by other materials. Because a bulky cooling system is urnecessary, these crystals could be useful in portable detector devices for nuclear power plant monitoring, natural resource prospecting, biomedical applications in diagnosis and therapy, and astronomical observation. Managed by the Marshall Space Flight Center, IML-1 was launched on January 22, 1992 aboard the Space Shuttle Orbiter Discovery (STS-42 mission).
Space-Time Crystal and Space-Time Group
NASA Astrophysics Data System (ADS)
Xu, Shenglong; Wu, Congjun
2018-03-01
Crystal structures and the Bloch theorem play a fundamental role in condensed matter physics. We extend the static crystal to the dynamic "space-time" crystal characterized by the general intertwined space-time periodicities in D +1 dimensions, which include both the static crystal and the Floquet crystal as special cases. A new group structure dubbed a "space-time" group is constructed to describe the discrete symmetries of a space-time crystal. Compared to space and magnetic groups, the space-time group is augmented by "time-screw" rotations and "time-glide" reflections involving fractional translations along the time direction. A complete classification of the 13 space-time groups in one-plus-one dimensions (1 +1 D ) is performed. The Kramers-type degeneracy can arise from the glide time-reversal symmetry without the half-integer spinor structure, which constrains the winding number patterns of spectral dispersions. In 2 +1 D , nonsymmorphic space-time symmetries enforce spectral degeneracies, leading to protected Floquet semimetal states. We provide a general framework for further studying topological properties of the (D +1 )-dimensional space-time crystal.
Space-Time Crystal and Space-Time Group.
Xu, Shenglong; Wu, Congjun
2018-03-02
Crystal structures and the Bloch theorem play a fundamental role in condensed matter physics. We extend the static crystal to the dynamic "space-time" crystal characterized by the general intertwined space-time periodicities in D+1 dimensions, which include both the static crystal and the Floquet crystal as special cases. A new group structure dubbed a "space-time" group is constructed to describe the discrete symmetries of a space-time crystal. Compared to space and magnetic groups, the space-time group is augmented by "time-screw" rotations and "time-glide" reflections involving fractional translations along the time direction. A complete classification of the 13 space-time groups in one-plus-one dimensions (1+1D) is performed. The Kramers-type degeneracy can arise from the glide time-reversal symmetry without the half-integer spinor structure, which constrains the winding number patterns of spectral dispersions. In 2+1D, nonsymmorphic space-time symmetries enforce spectral degeneracies, leading to protected Floquet semimetal states. We provide a general framework for further studying topological properties of the (D+1)-dimensional space-time crystal.
Update on the NASA Glenn Propulsion Systems Lab Ice Crystal Cloud Characterization (2015)
NASA Technical Reports Server (NTRS)
Van Zante, Judith F.; Bencic, Timothy J.; Ratvasky, Thomas P.
2016-01-01
NASA Glenn's Propulsion Systems Lab (PSL), an altitude engine test facility, was outfitted with a spray system to generate ice crystals. The first ice crystal characterization test occurred in 2012. At PSL, turbine engines and driven rigs can experience ice crystal icing at flight altitudes, temperatures and Mach numbers. To support these tests, four ice crystal characterizations have been conducted in two different facility configurations. In addition, super-cooled liquid and mixed phase clouds have also been generated. This paper will discuss the recent learning from the previous two calibrations. It will describe some of the 12-parameter calibration space, and how those parameters interact with each other, the instrumentation used to characterize the cloud and present a sample of the cloud characterization results.
NASA Technical Reports Server (NTRS)
Williams, Richard J.
1987-01-01
The Space Shuttle and the planned Space Station will permit experimentation under conditions of reduced gravitational acceleration offering experimental petrologists the opportunity to study crystal growth, element distribution, and phase chemistry. In particular the confounding effects of macro and micro scale buoyancy-induced convection and crystal settling or flotation can be greatly reduced over those observed in experiments in the terrestrial laboratory. Also, for experiments in which detailed replication of the environment is important, the access to reduced gravity will permit a more complete simulation of processes that may have occurred on asteroids or in free space. A technique that was developed to control, measure, and manipulate oxygen fugacities with small quantities of gas which are recirculated over the sample. This system could be adaptable to reduced gravity space experiments requiring redox control.
Space station needs, attributes and architectural options study. Volume 2: Mission analysis
NASA Technical Reports Server (NTRS)
1983-01-01
Space environment studies, astrophysics, Earth environment, life sciences, and material sciences are discussed. Commercial communication, materials processing, and Earth observation missions are addressed. Technology development, space operations, scenarios of operational capability, mission requirements, and benefits analysis results for space-produced gallium arsenide crystals, direct broadcasting satellite systems, and a high inclination space station are covered.
The First United States Microgravity Laboratory
NASA Technical Reports Server (NTRS)
Powers, C. Blake (Editor); Shea, Charlotte; Mcmahan, Tracy; Accardi, Denise; Mikatarian, Jeff
1991-01-01
The United States Microgravity Laboratory (USML-1) is one part of a science and technology program that will open NASA's next great era of discovery and establish the United States' leadership in space. A key component in the preparation for this new age of exploration, the USML-1 will fly in orbit for extended periods, providing greater opportunities for research in materials science, fluid dynamics, biotechnology, and combustion science. The major components of the USML-1 are the Crystal Growth Furnace, the Surface Tension Driven Convection Experiment (STDCE) Apparatus, and the Drop Physics Module. Other components of USML-1 include Astroculture, Generic Bioprocessing Apparatus, Extended Duration Orbiter Medical Project, Protein Crystal Growth, Space Acceleration Measurement System, Solid Surface Combustion Experiment, Zeolite Crystal Growth and Spacelab Glovebox provided by the European Space Agency.
NASA Astrophysics Data System (ADS)
Boopathi, K.; Babu, S. Moorthy; Ramasamy, P.
2018-04-01
Tetrabromo (piperazinium) zincate, a new metal-organic crystal has been synthesized and its single crystal grown by slow evaporation method. The grown crystal has characterized by structural, spectral, thermal, linear and nonlinear optical properties. Single crystal X-ray diffractions study reveals that grown crystal belongs to orthorhombic crystal system with space group P212121. The presence of functional groups is identified by FT-IR spectral analysis. Thermal stability of the crystal was ascertained by TG-DTA measurement. The second order harmonic generation efficiency was measured using Kurtz and Perry technique and it was found to be 1.5 times that of KDP.
Hosaka, Toshiaki; Okazaki, Masateru; Kimura-Someya, Tomomi; Ishizuka-Katsura, Yoshiko; Ito, Kaori; Yokoyama, Shigeyuki; Dodo, Kosuke; Sodeoka, Mikiko; Shirouzu, Mikako
2017-09-01
Voltage-dependent anion channel 1 (VDAC1), which is located in the outer mitochondrial membrane, plays important roles in various cellular processes. For example, oligomerization of VDAC1 is involved in the release of cytochrome c to the cytoplasm, leading to apoptosis. However, it is unknown how VDAC1 oligomerization occurs in the membrane. In the present study, we determined high-resolution crystal structures of oligomeric human VDAC1 (hVDAC1) prepared by using an Escherichia coli cell-free protein synthesis system, which avoided the need for denaturation and refolding of the protein. Broad-range screening using a bicelle crystallization method produced crystals in space groups C222 and P22 1 2 1 , which diffracted to a resolution of 3.10 and 3.15 Å, respectively. Each crystal contained two hVDAC1 protomers in the asymmetric unit. Dimer within the asymmetrical unit of the crystal in space group C222 were oriented parallel, whereas those of the crystal in space group P22 1 2 1 were oriented anti-parallel. From a model of the crystal in space group C222, which we constructed by using crystal symmetry operators, a heptameric structure with eight patterns of interaction between protomers, including hydrophobic interactions with β-strands, hydrophilic interactions with loop regions, and protein-lipid interactions, was observed. It is possible that by having multiple patterns of interaction, VDAC1 can form homo- or hetero-oligomers not only with other VDAC1 protomers but also with other proteins such as VDAC2, VDAC3 and apoptosis-regulating proteins in the Bcl-2 family. © 2017 The Protein Society.
Lab-on-a-Chip Based Protein Crystallization
NASA Technical Reports Server (NTRS)
vanderWoerd, Mark J.; Brasseur, Michael M.; Spearing, Scott F.; Whitaker, Ann F. (Technical Monitor)
2001-01-01
We are developing a novel technique with which we will grow protein crystals in very small volumes, utilizing chip-based, microfluidic ("LabChip") technology. This development, which is a collaborative effort between NASA's Marshall Space Flight Center and Caliper Technologies Corporation, promises a breakthrough in the field of protein crystal growth. Our initial results obtained from two model proteins, Lysozyme and Thaumatin, show that it is feasible to dispense and adequately mix protein and precipitant solutions on a nano-liter scale. The mixtures have shown crystal growth in volumes in the range of 10 nanoliters to 5 microliters. In addition, large diffraction quality crystals were obtained by this method. X-ray data from these crystals were shown to be of excellent quality. Our future efforts will include the further development of protein crystal growth with LabChip(trademark) technology for more complex systems. We will initially address the batch growth method, followed by the vapor diffusion method and the liquid-liquid diffusion method. The culmination of these chip developments is to lead to an on orbit protein crystallization facility on the International Space Station. Structural biologists will be invited to utilize the on orbit Iterative Biological Crystallization facility to grow high quality macromolecular crystals in microgravity.
Laser Development for Gravitational-Wave Interferometry in Space
NASA Technical Reports Server (NTRS)
Numata, Kenji; Camp, Jordan
2012-01-01
We are reporting on our development work on laser (master oscillator) and optical amplifier systems for gravitational-wave interferometry in space. Our system is based on the mature, wave-guided optics technologies, which have advantages over bulk, crystal-based, free-space optics. We are investing in a new type of compact, low-noise master oscillator, called the planar-waveguide external cavity diode laser. We made measurements, including those of noise, and performed space-qualification tests.
NASA Technical Reports Server (NTRS)
2003-01-01
In order to rapidly and efficiently grow crystals, tools were needed to automatically identify and analyze the growing process of protein crystals. To meet this need, Diversified Scientific, Inc. (DSI), with the support of a Small Business Innovation Research (SBIR) contract from NASA s Marshall Space Flight Center, developed CrystalScore(trademark), the first automated image acquisition, analysis, and archiving system designed specifically for the macromolecular crystal growing community. It offers automated hardware control, image and data archiving, image processing, a searchable database, and surface plotting of experimental data. CrystalScore is currently being used by numerous pharmaceutical companies and academic and nonprofit research centers. DSI, located in Birmingham, Alabama, was awarded the patent Method for acquiring, storing, and analyzing crystal images on March 4, 2003. Another DSI product made possible by Marshall SBIR funding is VaporPro(trademark), a unique, comprehensive system that allows for the automated control of vapor diffusion for crystallization experiments.
Wołoszyn, Łukasz; Ilczyszyn, Maria M
2018-03-15
Two new crystalline salts: β-alaninium trifluoromethanesulfonate (β-AlaOTf) and bis(β-alanine) trifluoromethanesulfonate (β-2AlaOTf) were obtained. The former one contains diprotonated β-alanine dimer, the latter one monoprotonated β-alanine dimer. Both compounds were studied by single crystal XRD, vibrational (IR and Raman) spectroscopy and calorimetric method. The quantum-mechanical calculations (DFT/B3LYP/6-311++G(2d,2p)) for the diprotonated dimer were carried out. The β-AlaOTf salt crystallizes in the P1¯ space group of triclinic system (Z=2), the β-2AlaOTf in the P2 1 /m space group of monoclinic system (Z=2). The vibrational data for the studied compounds are discussed in relation to their crystal structure, and provide insight into the character of hydrogen bonds and β-alanine protonation. The studied crystals do not exhibit phase transitions in the solid state. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Chandran, Senthilkumar; Paulraj, Rajesh; Ramasamy, P.
2017-05-01
Semi-organic lithium hydrogen oxalate monohydrate non-linear optical single crystals have been grown by slow evaporation solution growth technique at 35 °C. Single crystal X-ray diffraction study showed that the grown crystal belongs to the triclinic system with space group P1. The mechanical strength decreases with increasing load. The piezoelectric coefficient is found to be 1.41 pC/N. The nonlinear optical property was measured using Kurtz Perry powder technique and SHG efficiency was almost equal to that of KDP.
Growth of single crystals of mercuric iodide (HgI/sub 2/) in spacelab III
DOE Office of Scientific and Technical Information (OSTI.GOV)
Van Den Berg, L.; Schnepple, W.F.
1981-01-01
Continued development of a system designed to grow crystals by physical vapor transport in the environment of Spacelab III will be described, with special emphasis on simulation of expected space conditions, adjustment of crystal growth parameters, and on board observation and control of the experiment by crew members and ground personnel. A critical factor in the use of mercuric iodide for semiconductor detectors of x-rays and gamma-rays is the crystalline quality of the material. The twofold purpose of the Spacelab III experiment is therefore to grow single crystals with superior electronic properties as an indirect result of the greatly reducedmore » gravity field during the growth, and to obtain data which will lead to improved understanding of the vapor transport mechanism. The experiments planned to evaluate the space crystals, including gamma-ray diffractometry and measurements of stoichiometry, lattice dimensions, mechanical strength, luminescense, and detector performance are discussed.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Khan, Abdul Hamid; Chu, Fuliang; Feng, Youjun
2008-08-01
Crystallization of recombinant IgG-binding protein expressed in Escherichia coli using the hanging-drop vapour-diffusion method is described. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 38.98, b = 43.94, c = 78.17 Å. Streptococcus suis, an important zoonotic pathogen, expresses immunoglobulin G-binding protein, which is thought to be helpful to the organism in eluding the host defence system. Recombinant IgG-binding protein expressed in Escherichia coli has been crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 38.98, b = 43.94, c =more » 78.17 Å and one molecule in the asymmetric unit. Diffraction data were collected to 2.60 Å resolution.« less
Theoretical study of production of unique glasses in space
NASA Technical Reports Server (NTRS)
Larsen, D. C.
1974-01-01
Analytical functional relationships describing homogeneous nucleation and crystallization in various supercooled liquids were developed. The time and temperature dependent relationships of nucleation and crystallization (intrinsic properties) are being used to relate glass forming tendency to extrinsic parameters such as cooling rate through computer simulation. Single oxide systems are being studied initially to aid in developing workable kinetic models and to indicate the primary materials parameters affecting glass formation. The theory and analytical expressions developed for simple systems is then extended to complex oxide systems. A thorough understanding of nucleation and crystallization kinetics of glass forming systems provides a priori knowledge of the ability of a given system to form a glass.
Space-Time Crystals of Trapped Ions
2012-10-15
Spontaneous symmetry breaking can lead to the formation of time crystals, as well as spatial crystals. Here we propose a space- time crystal of...fields with fractional fluxes. The persistent rotation of trapped ions produces the temporal order, leading to the formation of a space- time crystal . We
NASA Technical Reports Server (NTRS)
Hu, Z. W.; Thomas, B. R.; Chernov, A. A.
2001-01-01
Double-axis multiple-crystal X-ray topography, rocking-curve measurements and triple-axis reciprocal-space mapping have been combined to characterize protein crystals using a laboratory source. Crystals of lysozyme and lysozyme crystals doped with acetylated lysozyme impurities were examined. It was shown that the incorporation of acetylated lysozyme into crystals of lysozyme induces mosaic domains that are responsible for the broadening and/or splitting of rocking curves and diffraction-space maps along the direction normal to the reciprocal-lattice vector, while the overall elastic lattice strain of the impurity-doped crystals does not appear to be appreciable in high angular resolution reciprocal-space maps. Multiple-crystal monochromatic X-ray topography, which is highly sensitive to lattice distortions, was used to reveal the spatial distribution of mosaic domains in crystals which correlates with the diffraction features in reciprocal space. Discussions of the influence of acetylated lysozyme on crystal perfection are given in terms of our observations.
Hu, Z W; Thomas, B R; Chernov, A A
2001-06-01
Double-axis multiple-crystal X-ray topography, rocking-curve measurements and triple-axis reciprocal-space mapping have been combined to characterize protein crystals using a laboratory source. Crystals of lysozyme and lysozyme crystals doped with acetylated lysozyme impurities were examined. It was shown that the incorporation of acetylated lysozyme into crystals of lysozyme induces mosaic domains that are responsible for the broadening and/or splitting of rocking curves and diffraction-space maps along the direction normal to the reciprocal-lattice vector, while the overall elastic lattice strain of the impurity-doped crystals does not appear to be appreciable in high angular resolution reciprocal-space maps. Multiple-crystal monochromatic X-ray topography, which is highly sensitive to lattice distortions, was used to reveal the spatial distribution of mosaic domains in crystals which correlates with the diffraction features in reciprocal space. Discussions of the influence of acetylated lysozyme on crystal perfection are given in terms of our observations.
Rekha, P; Peramaiyan, G; NizamMohideen, M; Kumar, R Mohan; Kanagadurai, R
2015-03-15
A novel organic single crystal of Piperazinium (bis) p-toluenesulfonate (PPTS) was grown by a slow evaporation solution growth technique. The structure of the grown crystal was determined using single crystal X-ray diffraction analysis. The PPTS crystal belongs to the triclinic crystal system with space group of P1¯. The presence of functional groups was confirmed by FTIR spectral analysis. The optical transmittance range and cut-off wavelength were identified by UV-vis-NIR spectral studies. The luminescent properties of PPTS crystal were investigated. The thermal behavior of PPTS crystal was studied by TG-DT analyses. Copyright © 2014 Elsevier B.V. All rights reserved.
Crystallization and preliminary X-ray analysis of gene product 44 from bacteriophage Mu
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kondou, Youhei; Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Toyama; Kitazawa, Daisuke
2005-01-01
Bacteriophage Mu baseplate protein gene product 44 was crystallized. The crystal belongs to space group R3, with unit-cell parameters a = b = 126.6, c = 64.2 Å. Bacteriophage Mu baseplate protein gene product 44 (gp44) is an essential protein required for the assembly of viable phages. To investigate the roles of gp44 in baseplate assembly and infection, gp44 was crystallized at pH 6.0 in the presence of 20% 2-methyl-2,4-pentanediol. The crystals belong to space group R3, with unit-cell parameters a = b = 127.47, c = 63.97 Å. The crystals diffract X-rays to at least 2.1 Å resolution andmore » are stable in the X-ray beam and are therefore appropriate for structure determination. Native data have been collected to 2.1 Å resolution using a DIP6040 image-plate system at beamline BL44XU at the SPring-8 facility in Japan.« less
NASA Technical Reports Server (NTRS)
Williams, R. J.
1986-01-01
The Space Shuttle and the planned Space Station will permit experimentation under conditions of reduced gravitational acceleration offering experimental petrologists the opportunity to study crystal growth, element distribution, and phase chemistry. In particular the confounding effects of macro and micro scale buoyancy-induced convection and crystal settling or floatation can be greatly reduced over those observed in experiments in the terrestrial laboratory. Also, for experiments in which detailed replication of the environment is important, the access to reduced gravity will permit a more complete simulation of processes that may have occurred on asteroids or in free space. A technique that was developed to control, measure, and manipulate oxygen fugacites with small quantities of gas which are recirculated over the sample is described. This system should be adaptable to reduced gravity space experiments requiring redox control. Experiments done conventionally and those done using this technique yield identical results done in a 1-g field.
NASA Technical Reports Server (NTRS)
Oliver, Michael J.
2015-01-01
The National Aeronautics and Space Administration conducted a full scale ice crystal icing turbofan engine test in the NASA Glenn Research Centers Propulsion Systems Laboratory (PSL) Facility in February 2013. Honeywell Engines supplied the test article, an obsolete, unmodified Lycoming ALF502-R5 turbofan engine serial number LF01 that experienced an un-commanded loss of thrust event while operating at certain high altitude ice crystal icing conditions. These known conditions were duplicated in the PSL for this testing.
Lv, C L; Liu, Q B; Cai, C Y; Huang, J; Zhou, G W; Wang, Y G
2015-01-01
In the transmission electron microscopy, a revised real space (RRS) method has been confirmed to be a more accurate dynamical electron diffraction simulation method for low-energy electron diffraction than the conventional multislice method (CMS). However, the RRS method can be only used to calculate the dynamical electron diffraction of orthogonal crystal system. In this work, the expression of the RRS method for non-orthogonal crystal system is derived. By taking Na2 Ti3 O7 and Si as examples, the correctness of the derived RRS formula for non-orthogonal crystal system is confirmed by testing the coincidence of numerical results of both sides of Schrödinger equation; moreover, the difference between the RRS method and the CMS for non-orthogonal crystal system is compared at the accelerating voltage range from 40 to 10 kV. Our results show that the CMS method is almost the same as the RRS method for the accelerating voltage above 40 kV. However, when the accelerating voltage is further lowered to 20 kV or below, the CMS method introduces significant errors, not only for the higher-order Laue zone diffractions, but also for zero-order Laue zone. These indicate that the RRS method for non-orthogonal crystal system is necessary to be used for more accurate dynamical simulation when the accelerating voltage is low. Furthermore, the reason for the increase of differences between those diffraction patterns calculated by the RRS method and the CMS method with the decrease of the accelerating voltage is discussed. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.
Single crystals of metal solid solutions
NASA Technical Reports Server (NTRS)
Miller, J. F.; Austin, A. E.; Richard, N.; Griesenauer, N. M.; Moak, D. P.; Mehrabian, M. R.; Gelles, S. H.
1974-01-01
The following definitions were sought in the research on single crystals of metal solid solutions: (1) the influence of convection and/or gravity present during crystallization on the substructure of a metal solid solution; (2) the influence of a magnetic field applied during crystallization on the substructure of a metal solid solution; and (3) requirements for a space flight experiment to verify the results. Growth conditions for the selected silver-zinc alloy system are described, along with pertinent technical and experimental details of the project.
NASA Astrophysics Data System (ADS)
Apreyan, R. A.; Fleck, M.; Atanesyan, A. K.; Sukiasyan, R. P.; Petrosyan, A. M.
2015-12-01
L-Nitroargininium picrate has been obtained from an aqueous solution containing equimolar quantities of L-nitroarginine and picric acid by slow evaporation. Single crystal was grown by evaporation method. Crystal structure was determined at room temperature. The salt crystallizes in monoclinic crystal system (space group P21). Vibrational spectra and thermal properties were studied. Second harmonic generation efficiency measured by powder method is found to be four times higher than in L-nitroarginine, which in turn is ten times more efficient than KDP (KH2PO4).
Single crystal growth and characterization of pure and sodium-modified copper tartrate
NASA Astrophysics Data System (ADS)
Quasim, I.; Firdous, A.; Want, B.; Khosa, S. K.; Kotru, P. N.
2008-12-01
Single crystal growth of pure and modified copper tartrate crystals bearing composition (Cu) x(Na) yC 4H 4O 6· nH 2O (where x=1, 0.77, 0.65; y=0, 0.23, 0.35) is achieved using gel technique. The optimum conditions required for the growth of these crystals are worked out. The morphological development of these crystals is studied using optical and scanning electron microscopy. The dominant habit faces of the grown copper tartrate crystals are (0 0 1) and (1 1 1). Calculation of the cell parameters using CRYSFIRE software suggests that the pure copper tartrate crystal belongs to orthorhombic system with space group P2 1/c whereas the modified copper tartrate falls under tetragonal system with the space group P4 2/nbc. The external morphological development is shown to remain unaffected in the modified copper tartrate. The stoichiometric composition of the crystals is established by EDAX analysis, CH analysis, FTIR spectroscopy and thermoanalytical techniques. Thermal analysis of the grown crystals suggests that pure copper tartrate is thermally stable up to 42.84 °C whereas the modified copper tartrate crystals are stable only up to 33.11 and 25.11 °C. Calculation of the percentage weight loss from the thermogram supplemented by EDAX/CH analysis and FTIR spectroscopy suggest that the chemical formula of pure copper tartrate crystal is CuC 4H 4O 6·3H 2O whereas the chemical formula for the modified copper tartrate crystals is (Cu) 0.77(Na) 0.23C 4H 4O 6·3H 2O and (Cu) 0.65(Na) 0.35 C 4H 4O 6·H 2O.
Protein crystallization aboard the Space Shuttle and the Mir space station
NASA Technical Reports Server (NTRS)
Delbaere, Louis T. J.; Vandonselaar, Margaret; Prasad, Lata; Quail, J. W.; Birnbaum, George I.; Delucas, Lawrence J.; Moore, Karen; Bugg, Charles E.
1993-01-01
Two different protein crystallizations, namely ,the free Fab fragment of the Je142 monoclonal antibody and the complex of Fab fragment/HPr with antigen, were performed aboard the Discovery Space Shuttle flights and the Mir space station, respectively. Medium sized crystals of the Je142 Fab fragment were obtained. The Je142 Fab fragment/Hpr complex produced two medium-sized crystals after two months aboard the Mir space station. Microgravity was found to eliminate the tendency of these crystals to form clusters.
Space-time crystals of trapped ions.
Li, Tongcang; Gong, Zhe-Xuan; Yin, Zhang-Qi; Quan, H T; Yin, Xiaobo; Zhang, Peng; Duan, L-M; Zhang, Xiang
2012-10-19
Spontaneous symmetry breaking can lead to the formation of time crystals, as well as spatial crystals. Here we propose a space-time crystal of trapped ions and a method to realize it experimentally by confining ions in a ring-shaped trapping potential with a static magnetic field. The ions spontaneously form a spatial ring crystal due to Coulomb repulsion. This ion crystal can rotate persistently at the lowest quantum energy state in magnetic fields with fractional fluxes. The persistent rotation of trapped ions produces the temporal order, leading to the formation of a space-time crystal. We show that these space-time crystals are robust for direct experimental observation. We also study the effects of finite temperatures on the persistent rotation. The proposed space-time crystals of trapped ions provide a new dimension for exploring many-body physics and emerging properties of matter.
Contamination and Radiation Effects on Nonlinear Crystals for Space Laser Systems
NASA Technical Reports Server (NTRS)
Abdeldayem, Hossain A.; Dowdye, Edward; Jamison, Tracee; Canham, John; Jaeger, Todd
2005-01-01
Space Lasers are vital tools for NASA s space missions and military applications. Although, lasers are highly reliable on the ground, several past space laser missions proved to be short-lived and unreliable. In this communication, we are shedding more light on the contamination and radiation issues, which are the most common causes for optical damages and laser failures in space. At first, we will present results based on the study of liquids and subsequently correlate these results to the particulates of the laser system environment. We present a model explaining how the laser beam traps contaminants against the optical surfaces and cause optical damages and the role of gravity in the process. We also report the results of the second harmonic generation efficiency for nonlinear optical crystals irradiated with high-energy beams of protons. In addition, we are proposing to employ the technique of adsorption to minimize the presence of adsorbing molecules present in the laser compartment.
Optical analysis of crystal growth
NASA Technical Reports Server (NTRS)
Workman, Gary L.; Passeur, Andrea; Harper, Sabrina
1994-01-01
Processing and data reduction of holographic images from Spacelab presents some interesting challenges in determining the effects of microgravity on crystal growth processes. Evaluation of several processing techniques, including the Computerized Holographic Image Processing System and the image processing software ITEX150, will provide fundamental information for holographic analysis of the space flight data.
Study of single crystals of metal solid solutions
NASA Technical Reports Server (NTRS)
Doty, J. P.; Reising, J. A.
1973-01-01
The growth of single crystals of relatively high melting point metals such as silver, copper, gold, and their alloys was investigated. The purpose was to develop background information necessary to support a space flight experiment and to generate ground based data for comparison. The ground based data, when compared to the data from space grown crystals, are intended to identify any effects which zero-gravity might have on the basic process of single crystal growth of these metals. The ultimate purposes of the complete investigation are to: (1) determine specific metals and alloys to be investigated; (2) grow single metal crystals in a terrestrial laboratory; (3) determine crystal characteristics, properties, and growth parameters that will be effected by zero-gravity; (4) evaluate terrestrially grown crystals; (5) grow single metal crystals in a space laboratory such as Skylab; (6) evaluate the space grown crystals; (7) compare for zero-gravity effects of crystal characteristics, properties, and parameters; and (8) make a recommendation as to production of these crystals as a routine space manufacturing proceses.
Containerless protein crystal growth method
NASA Technical Reports Server (NTRS)
Rhim, Won-Kyu; Chung, Sang K.
1991-01-01
A method of growing protein crystals from levitated drops is introduced and unique features of containerless approach in 1-g and micro-G laboratories are discussed. Electrostatic multidrop levitation system which is capable of simultaneous four drop levitation is described. A method of controlling protein saturation level in a programmed way is introduced and discussed. Finally, some of the unique features of containerless approach of protein crystal growth in space are discussed and summarized.
NASA Astrophysics Data System (ADS)
Zhang, Min; Liang, Zuozhong; Wu, Fei; Chen, Jian-Feng; Xue, Chunyu; Zhao, Hong
2017-06-01
We selected the crystal structures of ibuprofen with seven common space groups (Cc, P21/c, P212121, P21, Pbca, Pna21, and Pbcn), which was generated from ibuprofen molecule by molecular simulation. The predicted crystal structures of ibuprofen with space group P21/c has the lowest total energy and the largest density, which is nearly indistinguishable with experimental result. In addition, the XRD patterns for predicted crystal structure are highly consistent with recrystallization from solvent of ibuprofen. That indicates that the simulation can accurately predict the crystal structure of ibuprofen from the molecule. Furthermore, based on this crystal structure, we predicted the crystal habit in vacuum using the attachment energy (AE) method and considered solvent effects in a systematic way using the modified attachment energy (MAE) model. The simulation can accurately construct a complete process from molecule to crystal structure to morphology prediction. Experimentally, we observed crystal morphologies in four different polarity solvents compounds (ethanol, acetonitrile, ethyl acetate, and toluene). We found that the aspect ratio decreases of crystal habits in this ibuprofen system were found to vary with increasing solvent relative polarity. Besides, the modified crystal morphologies are in good agreement with the observed experimental morphologies. Finally, this work may guide computer-aided design of the desirable crystal morphology.
Vapor Crystal Growth System (VCGS) Team in the SL POCC During the STS-42 IML-1 Mission
NASA Technical Reports Server (NTRS)
1992-01-01
The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Vapor Crystal Growth System (VCGS) team in SL POCC), during STS-42, IML-1 mission.
Thermo-mechanical design and testing of a microbalance for space applications
NASA Astrophysics Data System (ADS)
Scaccabarozzi, Diego; Saggin, Bortolino; Tarabini, Marco; Palomba, Ernesto; Longobardo, Andrea; Zampetti, Emiliano
2014-12-01
This work focuses on the thermo-mechanical design of the microbalance used for the VISTA (Volatile In Situ Thermogravimetry Analyzer) sensor. VISTA has been designed to operate in situ in different space environments (asteroids, Mars, icy satellites). In this paper we focus on its application on Mars, where the expected environmental conditions are the most challenging for the thermo-mechanical design. The microbalance holding system has been designed to ensure piezoelectric crystal integrity against the high vibration levels during launch and landing and to cope with the unavoidable thermo-elastic differential displacements due to CTE and temperature differences between the microbalance elements. The crystal holding system, based on three symmetrical titanium supports, provides also the electrical connections needed for crystal actuation, microbalance heating and temperature measurement on the electrode area. On the microbalance crystal surfaces the electrodes, a micro film heater (optimized to perform thermo-gravimetric analysis up to 400 °C) and a resistive thermometer are deposited through a vacuum sputtering process. A mockup of the system has been manufactured and tested at the expected vibration levels and the thermal control effectiveness has been verified in thermo-vacuum environment.
The International Microgravity Laboratory, a Spacelab for materials and life sciences
NASA Technical Reports Server (NTRS)
Snyder, Robert S.
1992-01-01
The material science experiments performed on the International Microgravity Laboratory (IML-1), which is used to perform investigations which require the low gravity environment of space, are discussed. These experiments, the principal investigator, and associated organization are listed. Whether the experiment was a new development or was carried on an earlier space mission, such as the third Spacelab (SL-3) or the Shuttle Middeck, is also noted. The two major disciplines of materials science represented on IML-1 were the growth of crystals from the melt, solution, or vapor and the study of fluids (liquids and gases) in a reduced gravity environment. The various facilities on board IML-1 and their related experiments are described. The facilities include the Fluids Experiment System (FES) Vapor Crystal Growth System (VCGS) Organic Crystal Growth Facility (OCGF), Cryostat (CRY), and the Critical Point Facility (CPF).
Tachistoscopic exposure and masking of real three-dimensional scenes
Pothier, Stephen; Philbeck, John; Chichka, David; Gajewski, Daniel A.
2010-01-01
Although there are many well-known forms of visual cues specifying absolute and relative distance, little is known about how visual space perception develops at small temporal scales. How much time does the visual system require to extract the information in the various absolute and relative distance cues? In this article, we describe a system that may be used to address this issue by presenting brief exposures of real, three-dimensional scenes, followed by a masking stimulus. The system is composed of an electronic shutter (a liquid crystal smart window) for exposing the stimulus scene, and a liquid crystal projector coupled with an electromechanical shutter for presenting the masking stimulus. This system can be used in both full- and reduced-cue viewing conditions, under monocular and binocular viewing, and at distances limited only by the testing space. We describe a configuration that may be used for studying the microgenesis of visual space perception in the context of visually directed walking. PMID:19182129
Structural Variation of LaMnO3+δ by Oxygen Nonstoichiometry
NASA Astrophysics Data System (ADS)
Niwa, Eiki; Maeda, Hiroki; Hashimoto, Takuya; Mizusaki, Junichiro
2013-07-01
The relationship between oxygen content and crystal structure of LaMnO3+δ, which is mother phase of cathode material for solid oxide fuel cells, has been investigated by X-ray diffraction, thermogravimetry and iodometric titration. It was confirmed that LaMnO3+δ with different oxygen content can be prepared by controlling sintering temperature in static air. Crystal system of LaMnO3.17±0.02 and LaMnO3.13±0.01 at room temperature was rhombohedral with space group of Rbar {3}c, whereas crystal structure of LaMnO3.08±0.01 was orthorhombic whose space group was proposed to be Pmna (No. 53). With increase of oxygen content in LaMnO3+δ, molar volume decreased and higher crystal symmetry was obtained.
DNA-mediated nanoparticle crystallization into Wulff polyhedra
NASA Astrophysics Data System (ADS)
Auyeung, Evelyn; Li, Ting I. N. G.; Senesi, Andrew J.; Schmucker, Abrin L.; Pals, Bridget C.; de La Cruz, Monica Olvera; Mirkin, Chad A.
2014-01-01
Crystallization is a fundamental and ubiquitous process much studied over the centuries. But although the crystallization of atoms is fairly well understood, it remains challenging to predict reliably the outcome of molecular crystallization processes that are complicated by various molecular interactions and solvent involvement. This difficulty also applies to nanoparticles: high-quality three-dimensional crystals are mostly produced using drying and sedimentation techniques that are often impossible to rationalize and control to give a desired crystal symmetry, lattice spacing and habit (crystal shape). In principle, DNA-mediated assembly of nanoparticles offers an ideal opportunity for studying nanoparticle crystallization: a well-defined set of rules have been developed to target desired lattice symmetries and lattice constants, and the occurrence of features such as grain boundaries and twinning in DNA superlattices and traditional crystals comprised of molecular or atomic building blocks suggests that similar principles govern their crystallization. But the presence of charged biomolecules, interparticle spacings of tens of nanometres, and the realization so far of only polycrystalline DNA-interconnected nanoparticle superlattices, all suggest that DNA-guided crystallization may differ from traditional crystal growth. Here we show that very slow cooling, over several days, of solutions of complementary-DNA-modified nanoparticles through the melting temperature of the system gives the thermodynamic product with a specific and uniform crystal habit. We find that our nanoparticle assemblies have the Wulff equilibrium crystal structure that is predicted from theoretical considerations and molecular dynamics simulations, thus establishing that DNA hybridization can direct nanoparticle assembly along a pathway that mimics atomic crystallization.
Ingestible Thermometer Pill Aids Athletes in Beating the Heat
NASA Technical Reports Server (NTRS)
2006-01-01
Developed by Goddard Space Flight Center and the Johns Hopkins University Applied Physics Laboratory to monitor the core body temperature of astronauts during space flight, the ingestible "thermometer pill" has a silicone-coated exterior, with a microbattery, a quartz crystal temperature sensor, a space-aged telemetry system, and microminiaturized circuitry on the interior.
Reduced Iron Sulfide Systems for Removal of Heavy Metal Ions from Groundwater
2009-07-01
be gleaned from higher magnification of these samples. Each set of lattice fringes represents a single crystal of mackinawite (Ohfuji and Ricard...diffractograms, the diffraction peaks are broad and weak, indicating a poor degree of crystallization or a small crystallite size. For the non-magnetic...the lattice spacings of synthetic mackinawite in this study are shorter. The 3-day aging in this study resulted in a higher degree of crystallization
Bandyopadhyay, Rebanta; Selbo, Jon; Amidon, Gregory E; Hawley, Michael
2005-11-01
This study investigates the effects of crystal lattice deformation on the powder X-ray diffraction (PXRD) patterns of compressed polycrystalline specimen (compacts/tablets) made from molecular, crystalline powders. The displacement of molecules and the corresponding adjustment of interplanar distances (d-spacings) between diffracting planes of PNU-288034 and PNU-177553, which have crystal habits with a high aspect ratio favoring preferred orientation during tableting, are demonstrated by shifts in the diffracted peak positions. The direction of shift in diffracted peak positions suggests a reduction of interplanar d-spacing in the crystals of PNU-288034 and PNU-177553 following compaction. There is also a general reduction of peak intensities following compression at the different compressive loads. The lattice strain representing the reduction in d-spacing is proportional to the original d-spacing of the uncompressed sample suggesting that, as with systems that obey a simple Hooke's law relationship, the further apart the planes of atoms/molecules within the lattice are, the easier it is for them to approach each other under compressive stresses. For a third model compound comprising more equant-shaped crystals of PNU-141659, the shift in diffracted peak positions are consistent with an expansion of lattice spacing after compression. This apparent anomaly is supported by the PXRD studies of the bulk powder consisting of fractured crystals where also, the shift in peak position suggests expansion of the lattice planes. Thus the crystals of PNU-141659 may be fracturing under the compressive loads used to produce the compacts. Additional studies are underway to relate the PXRD observations with the bulk tableting properties of these model compounds.
NASA Astrophysics Data System (ADS)
Onoda, Masashige; Tamura, Asato
2017-02-01
The crystal structures, electronic properties, and spin dynamics of CuxV4O11 with 1.2 ≤ x < 2, classified as the partially Cu-extracted phase for the composite crystal system, are explored through measurements of x-ray four-circle diffraction, electrochemistry, electrical resistivity, thermoelectric power, magnetization, and electron paramagnetic resonance. This system has superlattice structures mainly ascribed to the partial ordering of Cu ions. Cu1.78V4O11 is triclinic with space group Pbar{1} and the double supercell of the V4O11 substructure of the composite crystal. The significantly Cu-extracted crystal Cu1.40V4O11 has a quadruple supercell with space group P1. The electron transport for V ions is nonmetallic owing to the polaronic nature and/or phonon softening and to the random potential of Cu ions. The Curie-Weiss-type paramagnetism basically originates from the Cu2+ chain coordinated octahedrally, and the EPR relaxation at low temperatures is understood through the exchange mechanism for the dipole-dipole and anisotropic exchange interactions. The near absence of paramagnetic behaviors of V4+ ions might be due to the spin-singlet ladder model or alternating-exchange chain model depending on the superlattice structure and valence distribution. The electrochemical performance of Li rechargeable batteries using this superlattice system is about 300 A h kg-1 at voltages above 2 V.
NASA Technical Reports Server (NTRS)
2001-01-01
Dr. Alexander Chernov, of the Universities Space Research Association (USRA) and based at Marshall Space Flight Center, is investigating why protein crystals grown in space are, in about 20 percent of cases, better-ordered than those grown on the ground. They are testing the idea that the amount of impurities trapped by space-grown crystals may be different than the amount trapped by crystals grown on Earth because convection is negligible in microgravity. The concentrations or impurities in many space-grown crystals turned out to be several times lower than that in the terrestrial ones, sometimes below the detection limit. The ground-based experiment also showed that the amount of impurities per unit volume of the crystals was usually higher than the amount per unit volume of the solution. This means that a growing crystal actually purifies the solution in its immediate vicinity. Here, an impurity depletion zone is created around apoferritin crystals grown in gel, imitating microgravity conditions.
Observation of a discrete time crystal.
Zhang, J; Hess, P W; Kyprianidis, A; Becker, P; Lee, A; Smith, J; Pagano, G; Potirniche, I-D; Potter, A C; Vishwanath, A; Yao, N Y; Monroe, C
2017-03-08
Spontaneous symmetry breaking is a fundamental concept in many areas of physics, including cosmology, particle physics and condensed matter. An example is the breaking of spatial translational symmetry, which underlies the formation of crystals and the phase transition from liquid to solid. Using the analogy of crystals in space, the breaking of translational symmetry in time and the emergence of a 'time crystal' was recently proposed, but was later shown to be forbidden in thermal equilibrium. However, non-equilibrium Floquet systems, which are subject to a periodic drive, can exhibit persistent time correlations at an emergent subharmonic frequency. This new phase of matter has been dubbed a 'discrete time crystal'. Here we present the experimental observation of a discrete time crystal, in an interacting spin chain of trapped atomic ions. We apply a periodic Hamiltonian to the system under many-body localization conditions, and observe a subharmonic temporal response that is robust to external perturbations. The observation of such a time crystal opens the door to the study of systems with long-range spatio-temporal correlations and novel phases of matter that emerge under intrinsically non-equilibrium conditions.
NASA Astrophysics Data System (ADS)
Doyle, Derek
The space industry has predominantly relied on high gain reflector dish antenna apertures for performing communications, but is constantly investing in phase array antenna concepts to provide increased signal flexibility at reduced system costs in terms of finances and system resources. The problem with traditional phased arrays remains the significantly greater program cost and complexity added to the satellite by integrating arrays of antenna elements with dedicated amplifier and phase shifters to perform adaptive beam forming. Liquid Crystal Reflectarrays (LiCRas) offer some of the electrical beam forming capability of a phased array system with the component and design complexity in lines with a traditional reflector antenna aperture but without the risks associated with mechanical steering systems. The final solution is believed to be a hybrid approach that performs in between the boundaries set by the two current disparate approaches. Practical reflectarrays have been developed since the 90's as a means to control reflection of incident radiation off a flat structure that is electrically curved based on radiating elements and their reflection characteristics with tailored element phase delay. In the last decade several methods have been proposed to enable tunable reflectarrays where the electrical shape of the reflector can be steered by controlling the resonating properties of the elements on the reflector using a DC bias. These approaches range from complex fast switching MEMS and ferroelectric devices, to more robust but slower chemical changes. The aim of this work is to investigate the feasibility of a molecular transition approach in the form of liquid crystals which change permittivity based on the electrical field they are subjected to. In this work, particular attention will be paid to the impact of space environment on liquid crystal reflectarray materials and reflector architectures. Of particular interest are the effects on performance induced by the temperature extremes of space and the electromagnetic particle environment. These two items tend to drive much of the research and development for various space technologies and based on these physical influences, assertions can be made toward the space worthiness of such a material approach and can layout future R&D; needs to make certain LC RF devices feasible for space use. Moreover, in this work the performance metrics of such a technology will be addressed along with methods of construction from a space perspective where specific design considerations must be made based on the extreme environment that a typical space asset must endure.
1998-01-05
The Interferometer Protein Crystal Growth (IPCG) experiment was designed to measure details of how protein molecules move through a fluid. It was flown on the STS-86 mission for use aboard Russian Space Station Mir in 1998. It studied aspects of how crystals grow - and what conditions lead to the best crystals, details that remain a mystery. IPCG produces interference patterns by spilitting then recombining laser light. This let scientists see how fluid densities - and molecular diffusion - change around a crystal as it grows in microgravity. The heart of the IPCG apparatus is the interferometer cell comprising the optical bench, microscope, other optics, and video camera. IPCG experiment cells are made of optical glass and silvered on one side to serve as a mirror in the interferometer system that visuzlizes crystals and conditions around them as they grow inside the cell. This diagram shows the optical layout. The principal investigator was Dr. Alexander McPherson of University of California, Irvine. Co-investigators are William Witherow and Dr. Marc Pusey of NASA's Marshall Space Flight Center (MSFC).
1998-01-05
The Interferometer Protein Crystal Growth (IPCG) experiment was designed to measure details of how protein molecules move through a fluid. It was flown on the STS-86 mission for use aboard Russian Space Station Mir in 1998. It studied aspects of how crystals grow - and what conditions lead to the best crystals, details that remain a mystery. IPCG produces interference patterns by spilitting then recombining laser light. This let scientists see how fluid densities - and molecular diffusion - change around a crystal as it grows in microgravity. The heart of the IPCG apparatus is the interferometer cell comprising the optical bench, microscope, other optics, and video camera. IPCG experiment cells are made of optical glass and silvered on one side to serve as a mirror in the interferometer system that visuzlizes crystals and conditions around them as they grow inside the cell. This view shows interferograms produced in ground tests. The principal investigator was Dr. Alexander McPherson of University of California, Irvine. Co-investigators are William Witherow and Dr. Marc Pusey of NASA's Marshall Space Flight Center (MSFC).
1998-01-05
The Interferometer Protein Crystal Growth (IPCG) experiment was designed to measure details of how protein molecules move through a fluid. It was flown on the STS-86 mission for use aboard Russian Space Station Mir in 1998. It studied aspects of how crystals grow - and what conditions lead to the best crystals, details that remain a mystery. IPCG produces interference patterns by spilitting then recombining laser light. This let scientists see how fluid densities - and molecular diffusion - change around a crystal as it grows in microgravity. The heart of the IPCG apparatus is the interferometer cell comprising the optical bench, microscope, other optics, and video camera. IPCG experiment cells are made of optical glass and silvered on one side to serve as a mirror in the interferometer system that visuzlizes crystals and conditions around them as they grow inside the cell. This diagram shows the growth cells. The principal investigator was Dr. Alexander McPherson of University of California, Irvine. Co-investigators are William Witherow and Dr. Marc Pusey of NASA's Marshall Space Flight Center (MSFC).
1998-01-05
The Interferometer Protein Crystal Growth (IPCG) experiment was designed to measure details of how protein molecules move through a fluid. It was flown on the STS-86 mission for use aboard Russian Space Station Mir in 1998. It studied aspects of how crystals grow - and what conditions lead to the best crystals, details that remain a mystery. IPCG produces interference patterns by spilitting then recombining laser light. This let scientists see how fluid densities - and molecular diffusion - change around a crystal as it grows in microgravity. The heart of the IPCG apparatus is the interferometer cell comprising the optical bench, microscope, other optics, and video camera. IPCG experiment cells are made of optical glass and silvered on one side to serve as a mirror in the interferometer system that visuzlizes crystals and conditions around them as they grow inside the cell. This view shows a large growth cell. The principal investigator was Dr. Alexander McPherson of University of California, Irvine. Co-investigators are William Witherow and Dr. Marc Pusey of NASA's Marshall Space Flight Center (MSFC).
2000-11-03
On the Space Shuttle Orbiter Atlantis' middeck, Astronaut Joseph R. Tarner, mission specialist, works at an area amidst several lockers which support the Protein Crystal Growth (PCG) experiment during the STS-66 mission. This particular section is called the Crystal Observation System, housed in the Thermal Enclosure System (COS/TES). Together with the Vapor Diffusion Apparatus (VDA), housed in Single Locker Thermal Enclosure (SLTES), the COS/TES represents the continuing research into the structure of proteins and other macromolecules such as viruses.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sugimoto, Keisuke; Matsufuzi, Kazuki; Ohnuma, Hiroaki
2006-02-01
PheB, an extradiol-cleaving catecholic dioxygenase, was crystallized by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The crystal belongs to the orthorhombic system, space group P2{sub 1}2{sub 1}2{sub 1}, and diffracts to 2.3 Å resolution. Class II extradiol-cleaving catecholic dioxygenase, a key enzyme of aromatic compound degradation in bacteria, cleaves the aromatic ring of catechol by adding two O atoms. PheB is one of the class II extradiol-cleaving catecholic dioxygenases and shows a high substrate specificity for catechol derivatives, which have one aromatic ring. In order to reveal the mechanism of the substrate specificity of PheB, PheB hasmore » been crystallized by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The space group of the obtained crystal was P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 65.5, b = 119.2, c = 158.7 Å. The crystal diffracted to 2.3 Å resolution.« less
Dynamically controlled crystal growth system
NASA Technical Reports Server (NTRS)
Bray, Terry L. (Inventor); Kim, Larry J. (Inventor); Harrington, Michael (Inventor); DeLucas, Lawrence J. (Inventor)
2002-01-01
Crystal growth can be initiated and controlled by dynamically controlled vapor diffusion or temperature change. In one aspect, the present invention uses a precisely controlled vapor diffusion approach to monitor and control protein crystal growth. The system utilizes a humidity sensor and various interfaces under computer control to effect virtually any evaporation rate from a number of different growth solutions simultaneously by means of an evaporative gas flow. A static laser light scattering sensor can be used to detect aggregation events and trigger a change in the evaporation rate for a growth solution. A control/follower configuration can be used to actively monitor one chamber and accurately control replicate chambers relative to the control chamber. In a second aspect, the invention exploits the varying solubility of proteins versus temperature to control the growth of protein crystals. This system contains miniature thermoelectric devices under microcomputer control that change temperature as needed to grow crystals of a given protein. Complex temperature ramps are possible using this approach. A static laser light scattering probe also can be used in this system as a non-invasive probe for detection of aggregation events. The automated dynamic control system provides systematic and predictable responses with regard to crystal size. These systems can be used for microgravity crystallization projects, for example in a space shuttle, and for crystallization work under terrestial conditions. The present invention is particularly useful for macromolecular crystallization, e.g. for proteins, polypeptides, nucleic acids, viruses and virus particles.
Crystal-free Formation of Non-Oxide Optical Fiber
NASA Technical Reports Server (NTRS)
Nabors, Sammy A.
2015-01-01
Researchers at NASA Marshall Space Flight Center have devised a method for the creation of crystal-free nonoxide optical fiber preforms. Non-oxide fiber optics are extensively used in infrared transmitting applications such as communication systems, chemical sensors, and laser fiber guides for cutting, welding and medical surgery. However, some of these glasses are very susceptible to crystallization. Even small crystals can lead to light scatter and a high attenuation coefficient, limiting their usefulness. NASA has developed a new method of non-oxide fiber formation that uses axial magnetic fields to suppress crystallization. The resulting non-oxide fibers are crystal free and have lower signal attenuation rates than silica based optical fibers.
Development of improved amorphous materials for laser systems
NASA Technical Reports Server (NTRS)
Neilson, G. F.; Weinberg, M. C.
1974-01-01
Crystallization calculations were performed in order to determine the possibility of forming a particular type of laser glass with the avoidance of devitrification in an outer space laboratory. It was demonstrated that under the homogenuous nucleating conditions obtainable in a zero gravity laboratory this laser glass may be easily quenched to a virtually crystal-free product. Experimental evidence is provided that use of this material as a host in a neodymium glass laser would result in more than a 10 percent increase in efficiency when compared to laser glass rods of a similar composition currently commercially available. Differential thermal analysis, thermal gradient oven, X-ray diffraction, and liquidus determination experiments were carried out to determine the basics of the crystallization behavior of the glass, and small-angle X-ray scattering and splat-cooling experiments were performed in order to provide additional evidence for the feasibility of producing this laser glass material, crystal free, in an outer space environment.
Critical coupling using the hexagonal boron nitride crystals in the mid-infrared range
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Jipeng; Wang, Hengliang; Wen, Shuangchun
2016-05-28
We theoretically demonstrate the perfect absorption phenomena in the hexagonal boron nitride (hBN) crystals in the mid-infrared wavelength ranges by means of critical coupling with a one-dimensional photonic crystal spaced by the air. Different from the polymer absorbing layer composed by a metal-dielectric composite film, the hyperbolic dispersion characteristics of hBN can meet the condition of critical coupling and achieve the total absorption in the mid-infrared wavelength ranges. However, the critical coupling phenomenon can only appear in the hBN crystals with the type II dispersion. Moreover, we discuss the influence of the thickness of hBN, the incident angle, and themore » thickness and permittivity of the space dielectric on the total absorption. Ultimately, the conditions for absorption enhancement and the optimization methods of perfect absorption are proposed, and the design rules for a totally absorbing system under the different conditions are achieved.« less
Johnson, Steven; Roversi, Pietro; Espina, Marianela; Deane, Janet E.; Birket, Susan; Picking, William D.; Blocker, Ariel; Picking, Wendy L.; Lea, Susan M.
2006-01-01
IpaD, the putative needle-tip protein of the Shigella flexneri type III secretion system, has been overexpressed and purified. Crystals were grown of the native protein in space group P212121, with unit-cell parameters a = 55.9, b = 100.7, c = 112.0 Å, and data were collected to 2.9 Å resolution. Analysis of the native Patterson map revealed a peak at 50% of the origin on the Harker section v = 0.5, suggesting twofold non-crystallographic symmetry parallel to the b crystallographic axis. As attempts to derivatize or grow selenomethionine-labelled protein crystals failed, in-drop proteolysis was used to produce new crystal forms. A trace amount of subtilisin Carlsberg was added to IpaD before sparse-matrix screening, resulting in the production of several new crystal forms. This approach produced SeMet-labelled crystals and diffraction data were collected to 3.2 Å resolution. The SeMet crystals belong to space group C2, with unit-cell parameters a = 139.4, b = 45.0, c = 99.5 Å, β = 107.9°. An anomalous difference Patterson map revealed peaks on the Harker section v = 0, while the self-rotation function indicates the presence of a twofold noncrystallographic symmetry axis, which is consistent with two molecules per asymmetric unit. PMID:16946465
Johnson, Steven; Roversi, Pietro; Espina, Marianela; Deane, Janet E; Birket, Susan; Picking, William D; Blocker, Ariel; Picking, Wendy L; Lea, Susan M
2006-09-01
IpaD, the putative needle-tip protein of the Shigella flexneri type III secretion system, has been overexpressed and purified. Crystals were grown of the native protein in space group P2(1)2(1)2(1), with unit-cell parameters a = 55.9, b = 100.7, c = 112.0 A, and data were collected to 2.9 A resolution. Analysis of the native Patterson map revealed a peak at 50% of the origin on the Harker section v = 0.5, suggesting twofold non-crystallographic symmetry parallel to the b crystallographic axis. As attempts to derivatize or grow selenomethionine-labelled protein crystals failed, in-drop proteolysis was used to produce new crystal forms. A trace amount of subtilisin Carlsberg was added to IpaD before sparse-matrix screening, resulting in the production of several new crystal forms. This approach produced SeMet-labelled crystals and diffraction data were collected to 3.2 A resolution. The SeMet crystals belong to space group C2, with unit-cell parameters a = 139.4, b = 45.0, c = 99.5 A, beta = 107.9 degrees . An anomalous difference Patterson map revealed peaks on the Harker section v = 0, while the self-rotation function indicates the presence of a twofold noncrystallographic symmetry axis, which is consistent with two molecules per asymmetric unit.
NASA Astrophysics Data System (ADS)
Mahadevan, M.; Arivanandhan, M.; Elangovan, K.; Anandan, P.; Ramachandran, K.
2017-07-01
Good quality single crystals of sodium acid phthalate (NaAP) were grown by slow evaporation technique. Single crystal X-ray diffraction study of the grown crystal reveals that the crystal belongs to orthorhombic system with space group B2ab. Fourier transform infrared spectrum confirms the presence of the functional groups of the grown material. Inductively coupled plasma emission spectroscopy analysis is used to confirm the presence of Na element in the sample. Thermal analysis of the NaAP crystal shows that the crystal is stable up to 140°C. Optical transmittance of the grown crystal was recorded in the wavelength range from 200 and 800 nm using UV-Vis-NIR spectrophotometer. The second harmonic generation of NaAP was analysed using Kurtz powder technique.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ashikawa, Yuji; Uchimura, Hiromasa; Fujimoto, Zui
2007-06-01
The NAD(P)H:ferredoxin oxidoreductase in carbazole 1,9a-dioxygenase from Janthinobacterium sp. J3 was crystallized and diffraction data were collected to 2.60 Å resolution. Carbazole 1,9a-dioxygenase (CARDO), which consists of an oxygenase component (CARDO-O) and the electron-transport components ferredoxin (CARDO-F) and ferredoxin reductase (CARDO-R), catalyzes dihydroxylation at the C1 and C9a positions of carbazole. CARDO-R was crystallized at 277 K using the hanging-drop vapour-diffusion method with the precipitant PEG 8000. Two crystal types (types I and II) were obtained. The type I crystal diffracted to a maximum resolution of 2.80 Å and belonged to space group P4{sub 2}2{sub 1}2, with unit-cell parameters amore » = b = 158.7, c = 81.4 Å. The type II crystal was obtained in drops from which type I crystals had been removed; it diffracted to 2.60 Å resolution and belonged to the same space group, with unit-cell parameters a = b = 161.8, c = 79.5 Å.« less
NASA Astrophysics Data System (ADS)
Shruthi, C.; Ravindrachary, V.; Guruswamy, B.; Lokanath, N. K.; Kumara, Karthik; Goveas, Janet
2018-05-01
Needle shaped brown coloured single crystal of the title compound was grown by slow evaporation technique using methanol as solvent. The grown crystal was characterized using FT-IR, Single crystal XRD, UV-visible and NLO studies. Crystal structure was confirmed by FT-IR study and the functional groups were identified. XRD study reveals that the crystal belongs to orthorhombic crystal system with pnaa space group and the corresponding cell parameters were calculated. UV-visible spectrum shows that the crystal is transparent in the entire visible region and absorption takes place in the UV-range. NLO efficiency of the crystal obtained 0.66 times that of urea was determined by SHG test. The intermolecular interaction and percentage contribution of each individual atom in the crystal lattice was quantized using Hirshfeld surface and 2D finger print analysis.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Yuntao, E-mail: caswyt@hotmail.com; Ren, Guohao, E-mail: rgh@mail.sic.ac.cn; Ding, Dongzhou
2012-10-15
The calcite phase of LuBO{sub 3} and ScBO{sub 3} polycrystalline powders were synthesized by solid state reaction method, and the Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce (x=0.2, 0.5, 0.7) single crystals were grown by the Czochralski method. A large composition deviation between the initial polycrystalline powders and final single crystal was confirmed by electron probe micro-analysis. Raman spectroscopy revealed that moderate lattice disorder was induced by scandium substitution. However, based on the single crystal X-ray study, we finally concluded that the crystal structure of lutetium scandium orthoborate still crystallized in the rhombohedral system belonging to R3{sup -}c. Furthermore, the relationship between themore » energies of the five 5d levels of Ce{sup 3+} and the crystalline environment was revealed. The total redshift, total crystal field splitting, and centroid shift of Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce{sup 3+} were calculated based on their VUV excitation spectra. The variations trend of these observed spectroscopic parameters was in accordance with the predicted ones. - Graphical abstract: The crystal structure of Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce is rhombohedral system with R3{sup -}c space group. The relationship between the energies of the five Ce{sup 3+} 5d levels and the crystalline environment is established. Highlights: Black-Right-Pointing-Pointer Moderate lattice disorder is induced by scandium doping. Black-Right-Pointing-Pointer The crystal structure of Lu{sub 1-x}Sc{sub x}BO{sub 3}:Ce is rhombohedral system with R3{sup -}c space group. Black-Right-Pointing-Pointer Relationship between energies of Ce{sup 3+} 5d levels and crystalline environment is established. Black-Right-Pointing-Pointer The spectroscopic parameters are experimentally and theoretically calculated.« less
NASA Technical Reports Server (NTRS)
1983-01-01
The history of NASA's materials processing in space activities is reviewed. Market projections, support requirements, orbital operations issues, cost estimates and candidate systems (orbiter sortie flight, orbiter serviced free flyer, space station, space station serviced free flyer) for the space production of semiconductor crystals are examined. Mission requirements are identified for materials processing, communications missions, bioprocessing, and for transferring aviation maintenance training technology to spacecraft.
NASA Astrophysics Data System (ADS)
Ezeorah, Julius Chigozie; Ossai, Valentine; Obasi, Lawrence Nnamdi; Elzagheid, Mohamed I.; Rhyman, Lydia; Lutter, Michael; Jurkschat, Klaus; Dege, Necmi; Ramasami, Ponnadurai
2018-01-01
The Schiff base 3-{(E)-[(2-hydroxyphenyl)imino]methyl}benzene-1,2-diol was synthesized by the condensation of 2,3-dihydroxybenzaldehyde and 2-aminophenol in water at room temperature. The crystal was grown using two solvents (dry methanol and 60% methanol). The compound was characterized using elemental microanalysis, IR, NMR, UV spectroscopies and single-crystal X-ray diffraction crystallography. The X-ray structure reveals that the Schiff base crystallizes as a methanol solvate in dry methanol with triclinic crystal system, space group P-1 and Z = 2 in the unit cell and as a non-methanol solvate in 60% methanol with triclinic crystal system, space group P-1 and Z = 4 in the unit cell. The compound showed absorption bands at 272, 389, 473 and 602 nm in DMSO. These bands were assigned as π → π ∗, n → π∗ and n-σ∗ transitions. The 473 and 602 nm bands in DMSO reveal that the compound exists in tautomeric forms. The presence of N-H, C-O and Cdbnd N stretching vibrations in the IR spectrum indicates that the compound is zwitterionic in the solid state. This study was supplemented using density functional theory method.
2001-01-24
Dr. Alexander Chernov, of the Universities Space Research Association (USRA) and based at Marshall Space Flight Center, is investigating why protein crystals grown in space are, in about 20 percent of cases, better-ordered than those grown on the ground. They are testing the idea that the amount of impurities trapped by space-grown crystals may be different than the amount trapped by crystals grown on Earth because convection is negligible in microgravity. The concentrations or impurities in many space-grown crystals turned out to be several times lower than that in the terrestrial ones, sometimes below the detection limit. The ground-based experiment also showed that the amount of impurities per unit volume of the crystals was usually higher than the amount per unit volume of the solution. This means that a growing crystal actually purifies the solution in its immediate vicinity. Here, an impurity depletion zone is created around apoferritin crystals grown in gel, imitating microgravity conditions.
Economic analysis of crystal growth in space
NASA Technical Reports Server (NTRS)
Ulrich, D. R.; Chung, A. M.; Yan, C. S.; Mccreight, L. R.
1972-01-01
Many advanced electronic technologies and devices for the 1980's are based on sophisticated compound single crystals, i.e. ceramic oxides and compound semiconductors. Space processing of these electronic crystals with maximum perfection, purity, and size is suggested. No ecomonic or technical justification was found for the growth of silicon single crystals for solid state electronic devices in space.
The study of single crystals for space processing and the effect of zero gravity
NASA Technical Reports Server (NTRS)
Lal, R. B.
1975-01-01
A study was undertaken to analyze different growth techniques affected by a space environment. Literature on crystal growth from melt, vapor phase and float zone was reviewed and the physical phenomena important for crystal growth in zero-gravity environment was analyzed. Recommendations for potential areas of crystal growth feasible for space missions are presented and a bibliography of articles in the area of crystal growth in general is listed.
A High Power Frequency Doubled Fiber Laser
NASA Technical Reports Server (NTRS)
Thompson, Robert J.; Tu, Meirong; Aveline, Dave; Lundblad, Nathan; Maleki, Lute
2003-01-01
This viewgraph presentation reports on the development of a high power 780 nm laser suitable for space applications of laser cooling. A possible solution is to use frequency doubling of high power 1560 nm telecom lasers. The presentation shows a diagram of the frequency conversion, and a graph of the second harmonic generation in one crystal, and the use of the cascading crystals. Graphs show the second harmonic power as a function of distance between crystals, second harmonic power vs. pump power, tunability of laser systems.
Mine, Shouhei; Nakamura, Tsutomu; Hirata, Kunio; Ishikawa, Kazuhiko; Hagihara, Yoshihisa; Uegaki, Koichi
2006-01-01
The crystallization and preliminary X-ray diffraction analysis of a catalytic domain of chitinase (PF1233 gene) from the hyperthermophilic archaeon Pyrococcus furiosus is reported. The recombinant protein, prepared using an Escherichia coli expression system, was crystallized by the hanging-drop vapour-diffusion method. An X-ray diffraction data set was collected at the undulator beamline BL44XU at SPring-8 to a resolution of 1.50 Å. The crystals belong to space group P212121, with unit-cell parameters a = 90.0, b = 92.8, c = 107.2 Å. PMID:16880559
NASA Astrophysics Data System (ADS)
Shruthi, C.; Ravindrachary, V.; Guruswamy, B.; Lokanath, N. K.; Kumara, Karthik; Goveas, Janet
2018-05-01
Needle shaped single crystal of the title compound was grown by slow evaporation solution growth technique using ethanol as solvent. The grown single crystal was characterized using FT-IR, Single crystal XRD and Thermal analysis. The FT-IR spectrum confirms the molecular structure and identifies the different functional groups present in the compound. Single crystal XRD study reveals that the crystallized compound belongs to the monoclinic crystal system with P21/c space group and the corresponding cell parameters were identified. The thermal stability of the material was determined using both TGA and DTA analysis. The intermolecular interaction of each individual atom in the crystal lattice was estimated using Hirshfeld surface and finger print analysis.
Integrated double-clad photonic crystal fiber amplifier
NASA Astrophysics Data System (ADS)
Liu, Jun; Gu, Yanran; Chen, Zilun
2017-10-01
This paper studies and fabricates an integrated double-clad photonic crystal fiber amplifier, which overcomes the shortcomings of space application and makes full use of excellent property of double-clad photonic crystal fiber. In the experiment, the (6 + 1) × 1 end-pump coupler with DC-PCF is fabricated. The six pump fibers are fabricated with 105 / 125μm (NA = 0.22) multi-mode fiber. The signal fiber is made of ordinary single-mode fiber SMF-28. Then we spliced the tapered fiber bundle to photonic crystal fiber. At last, we produce double-clad photonic crystal fiber with an end-cap that are able to withstand high average power and protect the system. We have fabricated an integrated Yb-double-clad photonic crystal fiber amplifier.
Interface demarcation in GaAs by current pulsing
NASA Technical Reports Server (NTRS)
Matthiesen, D. H.; Kafalas, J. A.; Duchene, G. A.; Bellows, A. H.
1990-01-01
GTE Laboratories is currently conducting a program to investigate the effect of convection in the melt on the properties of bulk grown gallium arsenide (GaAs). In addition to extensive ground based experimentation, a Get Away Special growth system has been developed to grow two GaAs crystals aboard the Space Shuttle, each with a one inch diameter. In order to perform a complete segregation analysis of the crystals grown in space, it is necessary to measure the interface shape and growth rate as well as the spatial distribution of the selenium dopant. The techniques for interface demarcation in selenium doped GaAs by current pulsing have been developed at GTE Laboratories and successful interface demarcation has been achieved for current pulses ranging from 20 to 90 amps, in both single crystal and polycrystalline regions.
Crystal growth of artificial snow
NASA Technical Reports Server (NTRS)
Kimura, S.; Oka, A.; Taki, M.; Kuwano, R.; Ono, H.; Nagura, R.; Narimatsu, Y.; Tanii, J.; Kamimiytat, Y.
1984-01-01
Snow crystals were grown onboard the space shuttle during STS-7 and STS-8 to facilitate the investigation of crystal growth under conditions of weightlessness. The experimental design and hardware are described. Space-grown snow crystals were polyhedrons looking like spheres, which were unlike snow crystals produced in experiments on Earth.
Quantum Information Science Research and Technical Assessment Project
2010-08-01
parameter space. This system incorporates heaters, deposition monitors, temperature sensors , and adjustable substrate holders and masks under high...thickness monitor; G = glass surfaces for transmission measurements; PD = photodiode; TC = thermocouple temperature sensors . Substrate Preparation...crystal due to the mass of material deposited on the crystal. By adjusting the distance of the sensor relative to the source and employing the ~1/R2
Physical phenomena related to crystal growth in the space environment
NASA Technical Reports Server (NTRS)
Chu, T. L.
1973-01-01
The mechanism of crystal growth which may be affected by the space environment was studied. Conclusions as to the relative technical and scientific advantages of crystal growth in space over earth bound growth, without regard to economic advantage, were deduced. It was concluded that the crucibleless technique will most directly demonstrate the unique effects of the greatly reduced gravity in the space environment. Several experiments, including crucibleless crystal growth using solar energy and determination of diffusion coefficients of common dopants in liquid silicon were recommended.
NASA Astrophysics Data System (ADS)
Kırca, Başak Koşar; Çakmak, Şükriye; Kütük, Halil; Odabaşoğlu, Mustafa; Büyükgüngör, Orhan
2018-01-01
This study treats about two successfully synthesized secondary amide compounds 3-Acetoxy-2-methyl-N-(phenyl)benzamide, I and 3-Acetoxy-2-methyl-N-(4-methylphenyl)benzamide, II. Compounds were characterized by FTIR, 1H NMR, 13C NMR and X-ray single crystal diffraction analysis techniques. Single crystal X-ray diffraction analyses show that while I crystallized in the orthorhombic system with space group Pbca, II crystallized in the triclinic system with space group P-1 and the asymmetric unit of II consists of two crystallographically independent molecules. Lattice constants are a = 7.9713 (3) Å, b = 9.5059 (3) Å, c = 37.1762 (2) Å, Z = 8 for I and a = 7.5579 (8) Å, b = 8.8601 (8) Å, c = 23.363 (3) Å, α = 97.011 (9) °, β = 96.932 (9)°, γ = 90.051 (8)°, Z = 4 for II. Crystallographic studies also show that the supramolecular structures were stabilized by intramolecular, intermolecular hydrogen bonds and Csbnd H … π interactions for both compounds. Characteristic amide bonds were observed in IR and NMR spectra.
NASA Astrophysics Data System (ADS)
Verma, Madhu; Gupta, Rashmi; Singh, Harjinder; Bamzai, K. K.
2018-04-01
The growth of cadmium doped magnesium hydrogen phosphate was successfully carried out by using room temperature solution technique i.e., gel encapsulation technique. Grown crystals were confirmed by single crystal X-ray diffraction (XRD). The structure of the grown crystal belongs to orthorhombic crystal system and crystallizes in centrosymmetric space group. Kinetics of the decomposition of the grown crystals were studied by non-isothermal analysis. Thermo gravimetric / differential thermo analytical (TG/DTA) studies revealed that the grown crystal is stable upto 119 °C. The various steps involved in the thermal decomposition of the material have been analysed using Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova equations for evaluating various kinetic parameters. The optical studies shows that the grown crystals possess wide transmittance in the visible region and significant optical band gap of 5.5ev with cut off wavelength of 260 nm.
2004-04-15
Comparison of Germanium Telluride (GeTe) Crystals grown on Earth (left) and in space (right) during the Skylab SL-3 mission. These crystals were grown using a vapor transport crystal growth method in the Multipurpose Electric Furnace System (MEFS). Crystals grown on earth are needles and platelettes with distorted surfaces and hollow growth habits. The length of the ground-based needle is approximately 2 mm and the average lenth of the platelets is 1 mm. The dull appearance of the Skylab crystals resulted from condensation of the transport agent during the long cooling period dictated by the Skylab furnace. In a dedicated process, this would be prevented by removing the ampoule from the furnace and quenching the vapor source.
Glycine glycinium picrate—Reinvestigation of the structure and vibrational spectra
NASA Astrophysics Data System (ADS)
Ghazaryan, V. V.; Fleck, M.; Petrosyan, A. M.
2011-01-01
The crystal of diglycine picrate (glycine glycinum picrate) has been obtained from an aqueous solution containing stoichiometric quantities of the components. The species crystallizes in the monoclinic system (space group P2 1/ c). The crystal structure was determined with high accuracy, IR and Raman spectra are discussed and compared with previous results, and the molecular structure is presented. It was shown that crystals of diglycine picrate obtained from the solution containing equimolar quantities may contain picric acid as impurity, which is the reason for the previously reported observation of second harmonic generation in this centrosymmetric crystal. With this example we want to point out the risk of misinterpretation of SHG signals in general.
NASA Astrophysics Data System (ADS)
Marchewka, M. K.; Pietraszko, A.
2008-02-01
The piperazinium bis(4-hydroxybenzenesulphonate) crystallizes from water solution at room temperature in P2 1/ c space group of monoclinic system. The crystals are built up of doubly protonated piperazinium cations and ionized 4-hydroxybenzenesulphonate anions that interact through weak hydrogen bonds of O-H⋯O and N-H⋯O type. Mutual orientation of anions is determined by non-conventional hydrogen bonds of C-H⋯π type. Room temperature powder FT IR and FT Raman measurements were carried out. The vibrational spectra are in full agreement with the structure obtained from X-ray crystallography. The big single crystals of the title salt can be grown.
Astronaut Joseph R. Tanner works with PCG experiment on middeck
1994-11-14
On the Space Shuttle Atlantis' mid-deck, astronaut Joseph R. Tanner, mission specialist, works at area amidst several lockers onboard the Shuttle which support the Protein Crystal Growth (PCG) experiment. This particular section is called the Crystal Observation System, housed in the Thermal Enclosure System (COS/TES). Together with the Vapor Diffusion Apparatus (VDA), housed in a Single Locker Thermal Enclosure (SLTES) which is out of frame, the Cos/TES represents the continuing research into the structures of proteins and other macromolecules such as viruses.
Porter, Joanne L.; Carr, Paul D.; Collyer, Charles A.; Ollis, David L.
2014-01-01
Dienelactone hydrolase (DLH) is a monomeric protein with a simple α/β-hydrolase fold structure. It readily crystallizes in space group P212121 from either a phosphate or ammonium sulfate precipitation buffer. Here, the structure of DLH at 1.85 Å resolution crystallized in space group C2 with two molecules in the asymmetric unit is reported. When crystallized in space group P212121 DLH has either phosphates or sulfates bound to the protein in crucial locations, one of which is located in the active site, preventing substrate/inhibitor binding. Another is located on the surface of the enzyme coordinated by side chains from two different molecules. Crystallization in space group C2 from a sodium citrate buffer results in new crystallographic protein–protein interfaces. The protein backbone is highly similar, but new crystal contacts cause changes in side-chain orientations and in loop positioning. In regions not involved in crystal contacts, there is little change in backbone or side-chain configuration. The flexibility of surface loops and the adaptability of side chains are important factors enabling DLH to adapt and form different crystal lattices. PMID:25005082
Quartz-like Crystals Found in Planetary Disks
NASA Technical Reports Server (NTRS)
2008-01-01
NASA's Spitzer Space Telescope has, for the first time, detected tiny quartz-like crystals sprinkled in young planetary systems. The crystals, which are types of silica minerals called cristobalite and tridymite, can be seen close-up in the black-and-white insets (cristobalite is on the left, and tridymite on the right). The main picture is an artist's concept of a young star and its swirling disk of planet-forming materials. Cristobalite and tridymite are thought to be two of many planet ingredients. On Earth, they are normally found as tiny crystals in volcanic lava flows and meteorites from space. These minerals are both related to quartz. For example, if you were to heat the familiar quartz crystals often sold as mystical tokens, the quartz would transform into cristobalite and tridymite. Because cristobalite and tridymite require rapid heating and cooling to form, astronomers say they were most likely generated by shock waves traveling through the planetary disks. The insets are Scanning Electron Microscope pictures courtesy of George Rossman of the California Institute of Technology, Pasadena, Calif.Barnes, Cindy L; Snell, Edward H; Kundrot, Craig E
2002-05-01
This paper reports results from the first biological crystal-growth experiment on the International Space Station (ISS). Crystals of thaumatin were grown using liquid-liquid diffusion in Tygon tubing transported in the Enhanced Gaseous Nitrogen Dewar (EGN). Different volume ratios and concentrations of protein and precipitant were used to test different adaptations of the vapor-diffusion crystallization recipe to the liquid-liquid diffusion method. The EGN warmed up from 77 to 273 K in about 4 d, about the same time it took to warm from 273 to 293 K. The temperature within the EGN was 293-297 K for the majority of the experiment. Air gaps that blocked liquid-liquid diffusion formed in the tubes. Nonetheless, crystals were grown. Synchrotron diffraction data collected from the best space-grown crystal extended to 1.28 A, comparable to previous studies of space-grown thaumatin crystals. The resolution of the best ground-control crystal was only 1.47 A. It is not clear if the difference in diffraction limit arises from factors other than crystal size. Improvements in temperature control and the elimination of air gaps are needed, but the results show that the EGN on the ISS can be used to produce space-grown crystals that diffract to high resolution.
NASA Technical Reports Server (NTRS)
Kundrot, Craig; Barnes, Cindy L.; Snell, Edward H.; Stinson, Thomas N. (Technical Monitor)
2002-01-01
This paper reports results from the first biological crystal growth experiment on the International Space Station (ISS). Crystals of thaumatin were grown using liquid-liquid diffusion in Tygon tubing transported in the Enhanced Gaseous Nitrogen Dewar (EGN). Different Volume ratios and concentrations of protein and precipitant were used to test different adaptations of the vapor diffusion crystallization recipe to the liquid-liquid diffusion method. The EGN warmed up from -196 C to 0 C in about four days, about the same time it took to warm from 0 C to 20 C. The temperature within the EGN was 20 - 24 C for the majority of the experiment. Air gaps that blocked liquid-liquid diffusion formed in the tubes. Nonetheless, crystals were grown. Synchrotron diffraction data collected from the best space grown crystal extended to 1.28 Angstroms, comparable to previous studies of space-grown thaumatin crystals. The resolution of the best ground control crystal was only 1.47 Angstroms. It is not clear if the difference in diffraction limit is due to factors other than crystal size. Improvements in temperature control and the elimination of air gaps are needed, but the results show that EGN on the ISS can be used to produce space grown crystals that diffract to high resolution.
Crystallization of Chicken Egg White Lysozyme from Assorted Sulfate Salts
NASA Technical Reports Server (NTRS)
Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.
1998-01-01
Chicken egg white lysozyme has been found to crystallize from ammonium, sodium, potassium, rubidium, magnesium, and manganese sulfates at acidic and basic pH, with protein concentrations from 60 to 190 mg/ml. Four different crystal morphologies have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed, Crystals grown at 15 C were generally tetragonal, with space group P43212. Crystallization at 20 C typically resulted in the formation of orthorhombic crystals, space group P21212 1. The tetragonal much less than orthorhombic morphology transition appeared to be a function of both the temperature and protein concentration, occurring between 15 and 20 C and between 100 and 125 mg/ml protein concentration. Crystallization from 0.8 -1.2M magnesium sulfate at pH 7.6 - 8.0 gave a hexagonal (trigonal) crystal form, space group P3121, which diffracted to 2.8 A. Ammonium sulfate was also found to result in a monoclinic form, space group C2. Small twinned monoclinic crystals of approx. 0.2 mm on edge were grown by dialysis followed by seeded sitting drop crystallization.
Research experiences on materials science in space aboard Salyut and Mir
NASA Technical Reports Server (NTRS)
Regel, Liya L.
1992-01-01
From 1980 through 1991 approximately 500 materials processing experiments were performed aboard the space stations Salyut 6, Salyut 7 and Mir. This includes work on catalysts, polymers, metals and alloys, optical materials, superconductors, electronic crystals, thin film semiconductors, super ionic crystals, ceramics, and protein crystals. Often the resulting materials were surprisingly superior to those prepared on earth. The Soviets were the first to fabricate a laser (CdS) from a crystal grown in space, the first to grow a heterostructure in space, the first super ionic crystal in space, the first crystals of CdTe and its alloys, the first zeolite crystals, the first protein crystals, the first chromium disilicide glass, etc. The results were used to optimize terrestrial materials processing operations in Soviet industry. The characteristics of these three space stations are reviewed, along with the advantages of a space station for materials research, and the problems encountered by the materials scientists who used them. For example, the stations and the materials processing equipment were designed without significant input from the scientific community that would be using them. It is pointed out that successful results have been achieved also by materials processing at high gravity in large centrifuges. This research is also continuing around the world, including at Clarkson University. It is recommended that experiments be conducted in centrifuges in space, in order to investigate the acceleration regime between earth's gravity and the microgravity achieved in orbiting space stations. One cannot expect to understand the influence of gravity on materials processing from only two data points, earth's gravity and microgravity. One must also understand the influence of fluctuations in acceleration on board space stations, the so-called 'g-jitter.' This paper is presented in outline and graphical form.
NASA Technical Reports Server (NTRS)
1987-01-01
Potential applications of robots for cost effective commercial microelectronic processes in space were studied and the associated robotic requirements were defined. Potential space application areas include advanced materials processing, bulk crystal growth, and epitaxial thin film growth and related processes. All possible automation of these processes was considered, along with energy and environmental requirements. Aspects of robot capabilities considered include system intelligence, ROM requirements, kinematic and dynamic specifications, sensor design and configuration, flexibility and maintainability. Support elements discussed included facilities, logistics, ground support, launch and recovery, and management systems.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liang, Ming-Li; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002; Marsh, Matthew
Two new vanadium tellurites, VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2), have been synthesized successfully with the use of hydrothermal reactions. The crystal structures of the two compounds were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the polar space group Pca2{sub 1} (No. 29) while compound 2 crystallizes in the centrosymmetric space group C2/c (No. 15). The topography of compound 1 reveals a two-dimensional, layered structure comprised of VO{sub 6} octahedral chains and TeO{sub 3}(OH) zig-zag chains. Compound 2, on the contrary, features a three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic framework withmore » Ba{sup 2+} ions filled into the 10-member ring helical tunnels. The [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic network is the first 3D vanadium tellurite framework to be discovered in the alkaline-earth vanadium tellurite system. Powder second harmonic generation (SHG) measurements indicate that compound 1 shows a weak SHG response of about 0.3×KDP (KH{sub 2}PO{sub 4}) under 1064 nm laser radiation. Infrared spectroscopy, elemental analysis, thermal analysis, and dipole moment calculations have also been carried out. - Graphical abstract: VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} (No. 29) while Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) crystallizes in the centrosymmetric space group C2/c (No. 15). - Highlights: • VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) have been synthesized successfully with the use of hydrothermal reactions. • VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} and displays a weak SHG response. • VTeO{sub 4}(OH) (1) represents only the fourth SHG-active material found in vanadium tellurite systems. • Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) exhibits a novel three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic framework.« less
NASA Astrophysics Data System (ADS)
Toramaru, A.; Yamauchi, S.
2012-04-01
Characteristic structures such as rhythmic layering, cress cumulate, cross bedding, perpendicular feldspar rock etc, are commonly observed in layered intrusion or shallow magmatic intrusions. These structures result from complex processes including thermal and compositional diffusions, crystallization, crystal settling, convection and interaction among three phases (crystals, bubble, melt). In order to understand how the differentiation proceeds in solidifying magma bodies from each characteristic structure together with chemical signatures, it is necessary to evaluate the relative importance among these elemental processes on structures. As an attempt to evaluate the effect of advection on a diffusion-related structure, we carried out an analog experiment of Liesegang system using lead-iodide (PbI2) crystallization in agar media which have been normally used to prohibit convection. In the ordinary Liesegang band formation experiments including only diffusion and crystallization kinetics without any advection and convection, the precipitation bands develop with regular spacing following a geometric progression due to two-component diffusion and reaction with supersaturation. This type of banding structure has been advocated as the same type of cyclic layering or vesicle layering (a sort of rhythmic layering) in dykes or sills. In order to see the effect of one-directional advection on Liesegang band, we apply the electric field (5 V to 25 V for a distance 15 cm) along the concentration gradient in agar media, thereby counteracting flows of lead anion Pb2+ and iodide ion I- are driven at constant velocities. The flows of anions and ions are equivalent to the permeable flows in porous media of crystal mush. The resultant precipitation structures exhibit very curious banding structure in which band spacings do not change with distance, are nearly constant and quite narrow, depending on the voltage, unlike those in ordinary Liesegang bands in which band spacings increase with distance following geometric progression. Further interestingly each band consists of a lot of very tiny irregular-shaped crystal aggregates. From experimental results and scaling arguments, with regard to the effect of one directional permeable flow on band spacing of cyclic layering, we propose a hypothesis of constant Peclet number that Peclet number (ratio of flow velocity to diffusive velocity) is nearly unity. By applying the hypothesis to natural examples, we can estimate a value of permeable flow velocity of interstitial melts in differentiating magma bodies from values of a band spacing and diffusivity data.
Crystal structure, spectral, thermal and dielectric studies of a new zinc benzoate single crystal
NASA Astrophysics Data System (ADS)
Bijini, B. R.; Prasanna, S.; Deepa, M.; Nair, C. M. K.; Rajendra Babu, K.
2012-11-01
Single crystals of zinc benzoate with a novel structure were grown in gel media. Sodium metasilicate of gel density 1.04 g/cc at pH 6 was employed to yield transparent single crystals. The crystal structure of the compound was ascertained by single crystal X-ray diffractometry. It was noted that the crystal belongs to monoclinic system with space group P21/c with unit cell parameters a = 10.669(1) Å, b = 12.995(5) Å, c = 19.119(3) Å, and β = 94.926(3)°. The crystal was seen to possess a linear polymeric structure along b-axis; with no presence of coordinated or lattice water. CHN analysis established the stoichiometric composition of the crystal. The existence of functional groups present in the single crystal system was confirmed by FT-IR studies. The thermal characteristic of the sample was analysed by TGA-DTA techniques, and the sample was found to be thermally stable up to 280 °C. The kinetic and thermodynamic parameters were also determined. UV-Vis spectroscopy corroborated the transparency of the crystal and revealed the optical band gap to be 4 eV. Dielectric studies showed decrease in the dielectric constant of the sample with increase in frequency.
NASA Technical Reports Server (NTRS)
Roberts, G. O.; Fowlis, W. W.; Miller, T. L.
1984-01-01
Numerical methods are used to design a spherical baroclinic flow model experiment of the large scale atmosphere flow for Spacelab. The dielectric simulation of radial gravity is only dominant in a low gravity environment. Computer codes are developed to study the processes at work in crystal growing systems which are also candidates for space flight. Crystalline materials rarely achieve their potential properties because of imperfections and component concentration variations. Thermosolutal convection in the liquid melt can be the cause of these imperfections. Such convection is suppressed in a low gravity environment. Two and three dimensional finite difference codes are being used for this work. Nonuniform meshes and implicit iterative methods are used. The iterative method for steady solutions is based on time stepping but has the options of different time steps for velocity and temperature and of a time step varying smoothly with position according to specified powers of the mesh spacings. This allows for more rapid convergence. The code being developed for the crystal growth studies allows for growth of the crystal as the solid-liquid interface. The moving interface is followed using finite differences; shape variations are permitted. For convenience in applying finite differences in the solid and liquid, a time dependent coordinate transformation is used to make this interface a coordinate surface.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pathuri, Puja; Nguyen, Emily Tam; Luecke, Hartmut, E-mail: hudel@uci.edu
2006-11-01
α-11 giardin from the intestinal protozoan parasite, G. lamblia has been cloned, expressed, purified and crystallized under two different conditions and in two different space groups. Crystals from the first condition diffracted to 1.1 Å and belong to a primitive orthorhombic space group and crystals obtained in the second condition diffracted to 2.93 Å and belong to a primitive monoclinic space group. α-11 Giardin, a protein from the annexin superfamily, is a 35.0 kDa protein from the intestinal protozoan parasite Giardia lamblia which triggers a form of diarrhea called giardiasis. Here, the cloning, expression, purification and the crystallization of α-11more » giardin under two different conditions and in two different space groups is reported. Crystals from the first condition diffracted to 1.1 Å and belong to a primitive orthorhombic space group, while crystals from the second condition, which included calcium in the crystallization solution, diffracted to 2.93 Å and belong to a primitive monoclinic space group. Determination of the detailed atomic structure of α-11 giardin will provide a better insight into its biological function and might establish whether this class of proteins is a potential drug target against giardiasis.« less
Operation of a New COTS Crystal Oscillator - CXOMHT over a Wide Temperature Range
NASA Technical Reports Server (NTRS)
Patterson, Richard; Hammoud, Ahmad
2011-01-01
Crystal oscillators are extensively used in electronic circuits to provide timing or clocking signals in data acquisition, communications links, and control systems, to name a few. They are affordable, small in size, and reliable. Because of the inherent characteristics of the crystal, the oscillator usually exhibits extreme accuracy in its output frequency within the intrinsic crystal stability. Stability of the frequency could be affected under varying load levels or other operational conditions. Temperature is one of those important factors that influence the frequency stability of an oscillator; as it does to the functionality of other electronic components. Electronics designed for use in NASA deep space and planetary exploration missions are expected to be exposed to extreme temperatures and thermal cycling over a wide range. Thus, it is important to design and develop circuits that are able to operate efficiently and reliably under in these harsh temperature environments. Most of the commercial-off-the-shelf (COTS) devices are very limited in terms of their specified operational temperature while very few custom-made commercial and military-grade parts have the ability to operate in a slightly wider range of temperature than those of the COTS parts. These parts are usually designed for operation under one temperature extreme, i.e. hot or cold, and do not address the wide swing in the operational temperature, which is typical of the space environment. For safe and successful space missions, electronic systems must therefore be designed not only to withstand the extreme temperature exposure but also to operate efficiently and reliably. This report presents the results obtained on the evaluation of a new COTS crystal oscillator under extreme temperatures.
NASA Astrophysics Data System (ADS)
Cheng, Xiao; Li, Feng; Han, Shenghua; Zhang, Yufei; Jiao, Chuanjun; Wei, Jinbei; Ye, Kaiqi; Wang, Yue; Zhang, Hongyu
2015-03-01
A series of unsymmetrical 1,3-diaryl-β-diketones 1-6 displaying molecular conformation-dependent fluorescence quantum yields have been synthesized. Crystals with planar molecular conformation such as 1, 2, 3 and 4 are highly fluorescent (φf: 39-53%), and the one holding slightly twisted conformation (5) is moderately luminescent (φf = 17%), while crystal 6 possessing heavily bent structure is completely nonluminous (φf ~ 0). The distinct fluorescence efficiencies are ascribed to their different molecular conformations, since all the crystals hold the same crystal system, space group and crystal packing structures. Additionally, the fluorescent crystals 1-5 display low threshold amplified spontaneous emission (ASE) with small full widths at half-maximum (FWHM: 3-7 nm), indicating their potential as candidates for organic crystal lasing devices.
Boggon, T J; Helliwell, J R; Judge, R A; Olczak, A; Siddons, D P; Snell, E H; Stojanoff, V
2000-07-01
A comprehensive study of microgravity and ground-grown chicken egg-white lysozyme crystals is presented using synchrotron X-ray reciprocal-space mapping, topography techniques and diffraction resolution. Microgravity crystals displayed reduced intrinsic mosaicities on average, but no differences in terms of strain over their ground-grown counterparts. Topographic analysis revealed that in the microgravity case the majority of the crystal was contributing to the peak of the reflection at the appropriate Bragg angle. In the ground-control case only a small volume of the crystal contributed to the intensity at the diffraction peak. The techniques prove to be highly complementary, with the reciprocal-space mapping providing a quantitative measure of the crystal mosaicity and strain (or variation in lattice spacing) and the topography providing a qualitative overall assessment of the crystal in terms of its X-ray diffraction properties. Structural data collection was also carried out at the synchrotron.
NASA Technical Reports Server (NTRS)
Boggon, T. J.; Helliwell, J. R.; Judge, Russell A.; Siddons, D. P.; Snell, Edward H.; Stojanoff, V.
2000-01-01
A comprehensive study of microgravity and ground grown chicken egg white lysozyme crystals is presented using synchrotron X-ray reciprocal space mapping, topography techniques and diffraction resolution. Microgravity crystals displayed, on average, reduced intrinsic mosaicities but no differences in terms of stress over their earth grown counterparts. Topographic analysis revealed that in the microgravity case the majority of the crystal was contributing to the peak of the reflection at the appropriate Bragg angle. In the earth case at the diffraction peak only a small volume of the crystal contributed to the intensity. The techniques prove to be highly complementary with the reciprocal space mapping providing a quantitative measure of the crystal mosaicity and stress (or variation in lattice spacing) and topography providing a qualitative overall assessment of the crystal in terms of its X-ray diffraction properties. Structural data collection was also carried out both at the synchrotron and in the laboratory.
Protein-crystal growth experiment (planned)
NASA Technical Reports Server (NTRS)
Fujita, S.; Asano, K.; Hashitani, T.; Kitakohji, T.; Nemoto, H.; Kitamura, S.
1988-01-01
To evaluate the effectiveness of a microgravity environment on protein crystal growth, a system was developed using 5 cubic feet Get Away Special payload canister. In the experiment, protein (myoglobin) will be simultaneously crystallized from an aqueous solution in 16 crystallization units using three types of crystallization methods, i.e., batch, vapor diffusion, and free interface diffusion. Each unit has two compartments: one for the protein solution and the other for the ammonium sulfate solution. Compartments are separated by thick acrylic or thin stainless steel plates. Crystallization will be started by sliding out the plates, then will be periodically recorded up to 120 hours by a still camera. The temperature will be passively controlled by a phase transition thermal storage component and recorded in IC memory throughout the experiment. Microgravity environment can then be evaluated for protein crystal growth by comparing crystallization in space with that on Earth.
The nature of geometric frustration in the Kob-Andersen mixture
NASA Astrophysics Data System (ADS)
Crowther, Peter; Turci, Francesco; Royall, C. Patrick
2015-07-01
Geometric frustration is an approach to the glass transition based upon the consideration of locally favoured structures (LFS), which are geometric motifs which minimise the local free energy. Geometric frustration proposes that a transition to a crystalline state is frustrated because these LFS do not tile space. However, this concept is based on icosahedra which are not always the LFS for a given system. The LFS of the popular Kob-Andersen (KA) model glassformer are the bicapped square antiprism, which does tile space. Such a LFS-crystal is indeed realised in the Al2Cu structure, which is predicted to be a low energy state for the KA model with a 2:1 composition. We, therefore, hypothesise that upon changing the composition in the KA model towards 2:1, geometric frustration may be progressively relieved, leading to larger and larger domains of LFS which would ultimately correspond to the Al2Cu crystal. Remarkably, rather than an increase, upon changing composition we find a small decrease in the LFS population, and the system remains impervious to nucleation of LFS crystals. We suggest that this may be related to the composition of the LFS, as only a limited subset is compatible with the crystal. We further demonstrate that the Al2Cu crystal will grow from a seed in the KA model with 2:1 composition and identify the melting temperature to be 0.447(2).
Kozyrev, A; Mitrofanov, I; Owens, A; Quarati, F; Benkhoff, J; Bakhtin, B; Fedosov, F; Golovin, D; Litvak, M; Malakhov, A; Mokrousov, M; Nuzhdin, I; Sanin, A; Tretyakov, V; Vostrukhin, A; Timoshenko, G; Shvetsov, V; Granja, C; Slavicek, T; Pospisil, S
2016-08-01
The recent availability of large volume cerium bromide crystals raises the possibility of substantially improving gamma-ray spectrometer limiting flux sensitivities over current systems based on the lanthanum tri-halides, e.g., lanthanum bromide and lanthanum chloride, especially for remote sensing, low-level counting applications or any type of measurement characterized by poor signal to noise ratios. The Russian Space Research Institute has developed and manufactured a highly sensitive gamma-ray spectrometer for remote sensing observations of the planet Mercury from the Mercury Polar Orbiter (MPO), which forms part of ESA's BepiColombo mission. The Flight Model (FM) gamma-ray spectrometer is based on a 3-in. single crystal of LaBr3(Ce(3+)) produced in a separate crystal development programme specifically for this mission. During the spectrometers development, manufacturing, and qualification phases, large crystals of CeBr3 became available in a subsequent phase of the same crystal development programme. Consequently, the Flight Spare Model (FSM) gamma-ray spectrometer was retrofitted with a 3-in. CeBr3 crystal and qualified for space. Except for the crystals, the two systems are essentially identical. In this paper, we report on a comparative assessment of the two systems, in terms of their respective spectral properties, as well as their suitability for use in planetary mission with respect to radiation tolerance and their propensity for activation. We also contrast their performance with a Ge detector representative of that flown on MESSENGER and show that: (a) both LaBr3(Ce(3+)) and CeBr3 provide superior detection systems over HPGe in the context of minimally resourced spacecraft and (b) CeBr3 is a more attractive system than LaBr3(Ce(3+)) in terms of sensitivities at lower gamma fluxes. Based on the tests, the FM has now been replaced by the FSM on the BepiColombo spacecraft. Thus, CeBr3 now forms the central gamma-ray detection element on the MPO spacecraft.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kozyrev, A., E-mail: kozyrev@mx.iki.rssi.ru; Mitrofanov, I.; Bakhtin, B.
The recent availability of large volume cerium bromide crystals raises the possibility of substantially improving gamma-ray spectrometer limiting flux sensitivities over current systems based on the lanthanum tri-halides, e.g., lanthanum bromide and lanthanum chloride, especially for remote sensing, low-level counting applications or any type of measurement characterized by poor signal to noise ratios. The Russian Space Research Institute has developed and manufactured a highly sensitive gamma-ray spectrometer for remote sensing observations of the planet Mercury from the Mercury Polar Orbiter (MPO), which forms part of ESA’s BepiColombo mission. The Flight Model (FM) gamma-ray spectrometer is based on a 3-in. singlemore » crystal of LaBr{sub 3}(Ce{sup 3+}) produced in a separate crystal development programme specifically for this mission. During the spectrometers development, manufacturing, and qualification phases, large crystals of CeBr{sub 3} became available in a subsequent phase of the same crystal development programme. Consequently, the Flight Spare Model (FSM) gamma-ray spectrometer was retrofitted with a 3-in. CeBr{sub 3} crystal and qualified for space. Except for the crystals, the two systems are essentially identical. In this paper, we report on a comparative assessment of the two systems, in terms of their respective spectral properties, as well as their suitability for use in planetary mission with respect to radiation tolerance and their propensity for activation. We also contrast their performance with a Ge detector representative of that flown on MESSENGER and show that: (a) both LaBr{sub 3}(Ce{sup 3+}) and CeBr{sub 3} provide superior detection systems over HPGe in the context of minimally resourced spacecraft and (b) CeBr{sub 3} is a more attractive system than LaBr{sub 3}(Ce{sup 3+}) in terms of sensitivities at lower gamma fluxes. Based on the tests, the FM has now been replaced by the FSM on the BepiColombo spacecraft. Thus, CeBr{sub 3} now forms the central gamma-ray detection element on the MPO spacecraft.« less
NASA Astrophysics Data System (ADS)
Yu, Tian; Gao, Peng; Wu, Tao; Tyson, Trevor; Lalancette, Roger
2013-03-01
Crystal structure, electric polarization and heat capacity measurements on the hexagonal multiferroic RMnO3 reveal that small R ion (Lu and lower cation size) systems are ferroelectric and possess the same space-group as YMnO3. Combined local and long range structural measurements were conducted by XAFS, PDF and single crystal and powder XRD methods. The influence of the Mn-O and R-O distribution on the electric polarization is discussed. Point charge estimates of the electrical polarization are given for comparison with the YMnO3 system. This work is supported by DOE Grant DE-FG02-07ER46402.
1998-01-05
The Interferometer Protein Crstal Growth (IPCG) experiment was designed to measure details of how protein molecules move through a fluid. It was flown on the STS-86 mission for use aboard Russin Space Station Mir in 1998. It studied aspects of how crystals grow - and what conditions lead to the best crystals, details that remain a mystery. IPCG produces interference patterns by splitting then recombining laser light. This let scientists see how fluid densities - and molecular diffusion - change around a crystal as it grows in microgravity. The heart of the IPCG apparatus is the interferometer cell comprising the optical bench, microscope, other optics, and video camera. IPCG experiment cells are made of optical glass and silvered on one side to serve as a mirror in the interferometer system that visualizes crystals and conditions around them as they grow inside the cell. This view shows the complete apparatus. The principal investigator was Dr. Alexander McPherson of the University of California, Irvin. Co-investigators are William Witherow and Dr. Marc Pusey of NASA's Marshall Space Flight Center
Plastic deformation treated as material flow through adjustable crystal lattice
NASA Astrophysics Data System (ADS)
Minakowski, P.; Hron, J.; Kratochvíl, J.; Kružík, M.; Málek, J.
2014-08-01
Looking at severe plastic deformation experiments, it seems that crystalline materials at yield behave as a special kind of anisotropic, highly viscous fluids flowing through an adjustable crystal lattice space. High viscosity provides a possibility to describe the flow as a quasi-static process, where inertial and other body forces can be neglected. The flow through the lattice space is restricted to preferred crystallographic planes and directions causing anisotropy. In the deformation process the lattice is strained and rotated. The proposed model is based on the rate form of the decomposition rule: the velocity gradient consists of the lattice velocity gradient and the sum of the velocity gradients corresponding to the slip rates of individual slip systems. The proposed crystal plasticity model allowing for large deformations is treated as the flow-adjusted boundary value problem. As a test example we analyze a plastic flow of an single crystal compressed in a channel die. We propose three step algorithm of finite element discretization for a numerical solution in the Arbitrary Lagrangian Eulerian (ALE) configuration.
Growth and structure of a new photonic crystal: Chlorine substituted chalcone
NASA Astrophysics Data System (ADS)
Sarveshwara, H. P.; Raghavendra, S.; A, Jayarama; Menezes, Anthoni Praveen; Dharmaprakash, S. M.
2015-06-01
A new organic photonic material 3-(2, 4-dichlorophenyl)-1-(2,5-dimethylthiophen-3-yl)propan-1-one(DMTP) has been synthesized and crystallised in acetone solution. The functional groups present in the new material were identified by FTIR spectroscopy. The material is optically transparent in the wavelength range of 400-1100 nm. The crystal structure of DMTP was determined by single crystal X-ray diffraction. The title compound crystallizes in monoclinic system with a centrosymmetric space group P21/c. The Z-scan study revealed that the optical limiting property exhibited by the DMTP molecule is based on the reverse saturable absorption phenomena.
NASA Astrophysics Data System (ADS)
Sangeeta, S.; Ahmad, K.; Noorussabah, N.; Bharti, S.; Mishra, M. K.; Sharma, S. R.; Choudhary, M.
2017-12-01
Two new Schiff bases 2-((E)-(4-bromo-2-chlorophenylimino)methyl)-4-bromophenol(HL1) and1-((E)-(4-bromo-2-chlorophenylimino)methyl)naphthalene-2-ol (HL2) and their new nickel (II) complexes [Ni(L1)2]·DMF(1) and [Ni(L2)2] (2) have been synthesized and characterized by various physico- chemical and spectroscopic methods. The solid-state structures of synthesized compounds were determined by single crystal X-ray crystallography, which revealed square planar geometry around Ni (II) ion. Infrared spectra, UV-Vis, thermal analysis and magnetic susceptibility measurements agreed with the observed crystal structures. The ligand (HL1) crystallized in the Orthorhombic system of the space group Pbca,a = 7.5485(4)Å, b = 11.5514(5) Å, c = 30.1370(14)Å, α = 90°, β = 90°, γ = 90°and Z = 8. Complex[Ni(L1)2]·DMF(1) crystallized in the Triclinic system of the space group P-1, a = 8.9954(3) Å, b = 9.4593(4) Å, c = 13.2657(5) Å, α = 101.478°, β = 99.595°, γ = 117.651°and Z = 2, whereas complex [Ni(L2)2]·(2) crystallized in the Monoclinic system of the space group P21/c, a = 9.301(9)Å, b = 12.149(8)Å, c = 13.792(10)Å, α = 90°, β = 106.35(4).°, γ = 90°and Z = 2. The Schiff bases (HL1and HL2) behaved as monobasic bidentate ligands possessing N and O donor atoms. The SOD activities of HL1 and its Ni (II) complex[Ni(L1)2]·DMF(1) have been measured using xanthine-xanthine oxidase as a source of superoxide radical and NBT assay as O2- scavenger. In vitro antimicrobial activities of the Ni(II) complexes (1) and (2)against Bacillus cereus and Staphylococcus aureus as Gram + ve and Salmonella typhi, Klebsiella pneumonia and Escherichia coli as Gram-ve species have been investigated comparing with the Schiff base ligands (HL1and HL2).
Protein crystal growth in space
NASA Technical Reports Server (NTRS)
Bugg, C. E.; Clifford, D. W.
1987-01-01
The advantages of protein crystallization in space, and the applications of protein crystallography to drug design, protein engineering, and the design of synthetic vaccines are examined. The steps involved in using protein crystallography to determine the three-dimensional structure of a protein are discussed. The growth chamber design and the hand-held apparatus developed for protein crystal growth by vapor diffusion techniques (hanging-drop method) are described; the experimental data from the four Shuttle missions are utilized to develop hardware for protein crystal growth in space and to evaluate the effects of gravity on protein crystal growth.
NASA Astrophysics Data System (ADS)
Zakharov, B. A.; Ghazaryan, V. V.; Boldyreva, E. V.; Petrosyan, A. M.
2015-11-01
Two crystalline salts have been obtained from the system L-serine - picric acid - H2O: L-serinium picrate monohydrate (I) and tris(L-serine) bis(L-serinium) dipicrate trihydrate (II). The salt (I) crystallizes in monoclinic system (space group P21, Z = 4). Asymmetric unit of (I) contains two formula units. Carboxyl groups of both L-serinium cations form hydrogen bonds with picrate anions with O···O distances: 2.595 (6) Å and 2.638 (5) Å. The salt (II) crystallizes in orthorhombic system (space group P212121, Z = 4). Asymmetric unit of (II) contains one formula unit. Carboxyl groups of both L-serinium cations form short O-H···O hydrogen bonds with two of three zwitterionic moieties, forming two dimeric (L-serine L-serinium) cations with O···O distances: 2.485 (3) Å and 2.487 (3) Å. The infrared and Raman spectra of obtained salts are recorded and discussed.
Experiences with Lab-on-a-chip Technology in Support of NASA Supported Research
NASA Technical Reports Server (NTRS)
Monaco, Lisa
2003-01-01
Under the auspices of the Microgravity Sciences and Application Department at Marshall Space Flight Center, we have custom designed and fabricated a lab-on-a-chip (LOC) device, along with Caliper Technologies, for macromolecular crystal growth. The chip has been designed to deliver specified proportions of up-to five various constituents to one of two growth wells (on-chip) for crystal growth. To date, we have grown crystals of thaumatin, glucose isomerase and appoferitin on the chip. The LOC approach offered many advantages that rendered it highly suitable for space based hardware to perform crystal growth on the International Space Station. The same hardware that was utilized for the crystal growth investigations, has also been used by researchers at Glenn Research Center to investigate aspects of microfluidic phenomenon associated with two-phase flow. Additionally, our LOCAD (Lab-on-a-chip Application Development) team has lent its support to Johnson Space Center s Modular Assay for Solar System Exploration project. At present, the LOCAD team is working on the design and build of a unique lab-on-a-chip breadboard control unit whose function is not commercially available. The breadboard can be used as a test bed for the development of chip size labs for environmental monitoring, crew health monitoring assays, extended flight pharmacological preparations, and many more areas. This unique control unit will be configured for local use and/or remote operation, via the Internet, by other NASA centers. The lab-on-a-chip control unit is being developed with the primary goal of meeting Agency level strategic goals.
Multiple Weyl points and the sign change of their topological charges in woodpile photonic crystals
NASA Astrophysics Data System (ADS)
Chang, Ming-Li; Xiao, Meng; Chen, Wen-Jie; Chan, C. T.
2017-03-01
We show that Weyl points with topological charges 1 and 2 can be found in very simple chiral woodpile photonic crystals and the distribution of the charges can be changed by changing the material parameters without altering space-group symmetry. The underlying physics can be understood through a tight-binding model. Gapless surface states and their backscattering immune properties also are demonstrated in these systems. Obtaining Weyl points in these easily fabricated woodpile photonic crystals will facilitate the realization of Weyl point physics in optical and IR frequencies.
Horsham, Matt; Saxby, Harriet; Blake, James; Isaacs, Neil W.; Mitchell, Tim J.; Riboldi-Tunnicliffe, Alan
2010-01-01
The enzyme transketolase from the lactic acid bacterium Lactobacillus salivarius (subsp. salivarius UCC118) has been recombinantly expressed and purified using an Escherichia coli expression system. Purified transketolase from L. salivarius has been crystallized using the vapour-diffusion technique. The crystals belonged to the trigonal space group P3221, with unit-cell parameters a = b = 75.43, c = 184.11 Å, and showed diffraction to 2.3 Å resolution. PMID:20693662
Protein Crystals Grown in Space
NASA Technical Reports Server (NTRS)
2000-01-01
A collage of protein and virus crystals, many of which were grown on the U.S. Space Shuttle or Russian Space Station, Mir. The crystals include the proteins canavalin; mouse monoclonal antibody; a sweet protein, thaumatin; and a fungal protease. Viruses are represented here by crystals of turnip yellow mosaic virus and satellite tobacco mosaic virus. The crystals are photographed under polarized light (thus causing the colors) and range in size from a few hundred microns in edge length up to more than a millimeter. All the crystals are grown from aqueous solutions and are useful for X-ray diffraction analysis. Credit: Dr. Alex McPherson, University of California, Irvine.
Growth of zeolite crystals in the microgravity environment of space
NASA Technical Reports Server (NTRS)
Sacco, A., Jr.; Sand, L. B.; Collette, D.; Dieselman, K.; Crowley, J.; Feitelberg, A.
1986-01-01
Zeolites are hydrated, crystalline aluminosilicates with alkali and alkaling earth metals substituted into cation vacancies. Typically zeolite crystals are 3 to 8 microns. Larger cyrstals are desirable. Large zeolite crystals were produced (100 to 200 microns); however, they have taken restrictively long times to grow. It was proposed if the rate of nucleation or in some other way the number of nuclei can be lowered, fewer, larger crystals will be formed. The microgravity environment of space may provide an ideal condition to achieve rapid growth of large zeolite crystals. The objective of the project is to establish if large zeolite crystals can be formed rapidly in space.
Resolution of holograms produced by the fluid experiment system and the holography ground system
NASA Technical Reports Server (NTRS)
Brooks, Howard L.
1987-01-01
The Fluid Experiment System (FES) was developed to study low temperature crystal growth of triglycine sulfate from solution in a low gravity environment onboard Spacelab. The first flight of FES was in 1985. FES uses an optical system to take holograms of the growing crystal to be analyzed after the mission in the Holography Ground System (HGS) located in the Test Laboratory at Marshall Space Flight Center. Microscopic observation of the images formed by the reconstructed holograms is critical to determining crystal growth rate and particle velocity. FES and HGS were designed for a resolution of better than 20 micrometers, but initial observation of the flight holograms show a limit of 80 micrometers. The resolution of the FES holograms is investigated, as well as the role of beam intensity ratio and exposure time on the resolution of HGS produced holograms.
STS-66 Space Shuttle mission report
NASA Technical Reports Server (NTRS)
Fricke, Robert W., Jr.
1995-01-01
The primary objective of this flight was to accomplish complementary science objectives by operating the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3) and the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite (CRISTA-SPAS). The secondary objectives of this flight were to perform the operations of the Shuttle Solar Backscatter Ultraviolet/A (SSBUV/A) payload, the Experiment of the Sun Complementing the Atlas Payload and Education-II (ESCAPE-II) payload, the Physiological and Anatomical Rodent Experiment/National Institutes of Health Rodents (PARE/NIH-R) payload, the Protein Crystal Growth-Thermal Enclosure System (PCG-TES) payload, the Protein Crystal Growth-Single Locker Thermal Enclosure System (PCG-STES), the Space Tissue/National Institutes of Health Cells STL/N -A payload, the Space Acceleration Measurement Systems (SAMS) Experiment, and Heat Pipe Performance Experiment (HPPE) payload. The 11-day plus 2 contingency day STS-66 mission was flown as planned, with no contingency days used for weather avoidance or Orbiter contingency operations. Appendix A lists the sources of data from which this report was prepared, and Appendix B defines all acronyms and abbreviations used in the report.
STS-66 Space Shuttle mission report
NASA Astrophysics Data System (ADS)
Fricke, Robert W., Jr.
1995-02-01
The primary objective of this flight was to accomplish complementary science objectives by operating the Atmospheric Laboratory for Applications and Science-3 (ATLAS-3) and the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite (CRISTA-SPAS). The secondary objectives of this flight were to perform the operations of the Shuttle Solar Backscatter Ultraviolet/A (SSBUV/A) payload, the Experiment of the Sun Complementing the Atlas Payload and Education-II (ESCAPE-II) payload, the Physiological and Anatomical Rodent Experiment/National Institutes of Health Rodents (PARE/NIH-R) payload, the Protein Crystal Growth-Thermal Enclosure System (PCG-TES) payload, the Protein Crystal Growth-Single Locker Thermal Enclosure System (PCG-STES), the Space Tissue/National Institutes of Health Cells STL/N -A payload, the Space Acceleration Measurement Systems (SAMS) Experiment, and Heat Pipe Performance Experiment (HPPE) payload. The 11-day plus 2 contingency day STS-66 mission was flown as planned, with no contingency days used for weather avoidance or Orbiter contingency operations. Appendix A lists the sources of data from which this report was prepared, and Appendix B defines all acronyms and abbreviations used in the report.
Solution Growth and Characterization of Single Crystals on Earth and in Microgravity
NASA Technical Reports Server (NTRS)
Aggarwal, M. D.; Currie, J. R.; Penn, B. G.; Batra, A. K.; Lal, R. B.
2007-01-01
Crystal growth has been of interest to physicists and engineers for a long time because of their unique properties. Single crystals are utilized in such diverse applications as pharmaceuticals, computers, infrared detectors, frequency measurements, piezoelectric devices, a variety of high-technology devices, and sensors. Solution crystal growth is one of the important techniques to grow a variety of crystals when the material decomposes at the melting point and a suitable solvent is available to make a saturated solution at a desired temperature. In this Technical Memorandum (TM) an attempt is made to give the fundamentals of growing crystals from solution including improved designs of various crystallizers. Since the same solution crystal growth technique could not be used in microgravity, the authors proposed a new cooled-sting technique to grow crystals in space. The authors experience from conducting two Space Shuttle solution crystal growth experiments are also detailed in this TM and the complexity of solution growth experiments to grow crystals in space are also discussed. These happen to be some of the early experiments performed in space, and various lessons learned are described. A brief discussion of protein crystal growth that shares basic principles of the solution growth technique is given, along with some flight hardware information for growth in microgravity.
Growth and Characteristics of Bulk Single Crystals Grown from Solution on Earth and in Microgravity
NASA Technical Reports Server (NTRS)
Aggarwal, M. D.; Batra, A. K.; Lal, R. B.; Penn, Benjamin G.; Frazier, Donald O.
2011-01-01
The growth of crystals has been of interest to physicists and engineers for a long time because of their unique properties. Single crystals are utilized in such diverse applications as pharmaceuticals, computers, infrared detectors, frequency measurements, piezoelectric devices, a variety of high technology devices and sensors. Solution crystal growth is one of the important techniques to grow a variety of crystals when the material decomposes at the melting point and a suitable solvent is available to make a saturated solution at a desired temperature. In this chapter an attempt is made to give some fundamentals of growing crystals from solution including improved designs of various crystallizers. Since the same solution crystal growth technique could not be used in microgravity, authors had proposed a new cooled sting technique to grow crystals in space. Authors? experiences of conducting two space shuttle experiments relating to solution crystal growth are also detailed in this work. The complexity of these solution growth experiments to grow crystals in space are discussed. These happen to be some of the early experiments performed in space, and various lessons learned are described. A brief discussion of protein crystal growth that also shares basic principles of solution growth technique is given along with some flight hardware information for its growth in microgravity.
NASA Technical Reports Server (NTRS)
Palosz, Witold
1998-01-01
Presence of different, non-constituent gases may be a critical factor in crystal growth systems. In Physical Vapor Transport processes the cras(es) can be used intentionally (to prevent excessively high, unstable growth conditions), or can evolve unintentionally during the course of the process (which may lead to undesired reduction in the -rowth rate). In melt growth, particularly under low gravity conditions (reduced hydrostatic pressure) the gas present in the system may contribute to formation of voids in the growing crystals and even to a separation of the crystal and the liquid phase [1]. On the other hand, some amount of gas may facilitate 'contactless' crystal growth particularly under reduced gravity conditions [2 - 6]. Different non-constituent gases may be present in growth ampoules, and their amount and composition may change during the crystallization process. Some gases can appear even in empty ampoules sealed originally under high vacuum: they may diffuse in from the outside, and/or desorb from the ampoule walls. Residual gases can also be generated by the source materials: even very high purity commercial elements and compounds may contain trace amounts of impurities, particularly oxides. The oxides may have low volatilities themselves but their reaction with other species, particularly carbon and hydrogen, may produce volatile compounds like water or carbon oxides. The non-constituent gases, either added initially to the system or evolved during the material processing, may diffuse out of the ampoule during the course of the experiment. Gases present outside (e.g. as a protective atmosphere or thermal conductor) may diffuse into the ampoule. In either case the growth conditions and the quality of the crystals may be affected. The problem is of a particular importance in sealed systems where the amount of the gases cannot be directly controlled. Therefore a reasonable knowledge and understanding of the origin, composition, magnitude, and change with time of gases present in sealed ampoules may be important for a meaningful control and interpretation of crystal growth processes. This problem is of a particular importance for processing of electronic materials in space because (i) safety considerations require using sealed systems only, and (ii) high cost of crystal growth experiments in microgravity calls for a throughout, accurate description of the processing conditions necessary for a meaningful, efficient, and conclusive interpretation of the space results. In this paper we present the results of our extensive studies on gases in closed crystal growth systems which include: (a) Degassing properties of fused silica; (b) Generation of inert gases by source materials (CdTe, ZnTe, CdZnTe, ZnSe, PbTe, PbSe, PbSeTe); (c) Diffusive cas losses from silica glass ampoules.
Astronaut Curtis Brown works with SAMS on Shuttle Atlantis middeck
1994-11-14
STS066-14-021 (3-14 Nov 1994) --- On the Space Shuttle Atlantis' mid-deck, astronaut Curtis L. Brown, Jr., pilot, works with the Space Acceleration Measurement System (SAMS), which is making its eleventh Shuttle flight. This system supports the Protein Crystal Growth (PCG) experiments onboard by collecting and recording data characterizing the microgravity environment in the Shuttle mid-deck. Brown joined four other NASA astronauts and a European Space Agency (ESA) astronaut for 11-days aboard Atlantis in support of the Atmospheric Laboratory for Applications and Science (ATLAS-3) mission.
NASA Astrophysics Data System (ADS)
Yang, Yuting; Xu, Yun Fei; Xu, Tao; Wang, Hai-Xiao; Jiang, Jian-Hua; Hu, Xiao; Hang, Zhi Hong
2018-05-01
We demonstrate experimentally that a photonic crystal made of Al2O3 cylinders exhibits topological time-reversal symmetric electromagnetic propagation, similar to the quantum spin Hall effect in electronic systems. A pseudospin degree of freedom in the electromagnetic system representing different states of orbital angular momentum arises due to a deformation of the photonic crystal from the ideal honeycomb lattice. It serves as the photonic analogue to the electronic Kramers pair. We visualized qualitatively and measured quantitatively that microwaves of a specific pseudospin propagate only in one direction along the interface between a topological photonic crystal and a trivial one. As only a conventional dielectric material is used and only local real-space manipulations are required, our scheme can be extended to visible light to inspire many future applications in the field of photonics and beyond.
Tunable Optical Filters for Space Exploration
NASA Technical Reports Server (NTRS)
Crandall, Charles; Clark, Natalie; Davis, Patricia P.
2007-01-01
Spectrally tunable liquid crystal filters provide numerous advantages and several challenges in space applications. We discuss the tradeoffs in design elements for tunable liquid crystal birefringent filters with special consideration required for space exploration applications. In this paper we present a summary of our development of tunable filters for NASA space exploration. In particular we discuss the application of tunable liquid crystals in guidance navigation and control in space exploration programs. We present a summary of design considerations for improving speed, field of view, transmission of liquid crystal tunable filters for space exploration. In conclusion, the current state of the art of several NASA LaRC assembled filters is presented and their performance compared to the predicted spectra using our PolarTools modeling software.
Biomineral nanoparticles are space-filling
NASA Astrophysics Data System (ADS)
Yang, Li; Killian, Christopher E.; Kunz, Martin; Tamura, Nobumichi; Gilbert, P. U. P. A.
2011-02-01
Sea urchin biominerals have been shown to form from aggregating nanoparticles of amorphous calcium carbonate (ACC), which then crystallize into macroscopic single crystals of calcite. Here we measure the surface areas of these biominerals and find them to be comparable to those of space-filling macroscopic geologic calcite crystals. These biominerals differ from synthetic mesocrystals, which are invariably porous. We propose that space-filling ACC is the structural precursor for echinoderm biominerals.Sea urchin biominerals have been shown to form from aggregating nanoparticles of amorphous calcium carbonate (ACC), which then crystallize into macroscopic single crystals of calcite. Here we measure the surface areas of these biominerals and find them to be comparable to those of space-filling macroscopic geologic calcite crystals. These biominerals differ from synthetic mesocrystals, which are invariably porous. We propose that space-filling ACC is the structural precursor for echinoderm biominerals. This article was submitted as part of a Themed Issue on Crystallization and Formation Mechanisms of Nanostructures. Other papers on this topic can be found in issue 11 of vol. 2 (2010). This issue can be found from the Nanoscale homepage [http://www.rsc.org/nanoscale
Ishak, Siti Nor Hasmah; Aris, Sayangku Nor Ariati Mohamad; Halim, Khairul Bariyyah Abd; Ali, Mohd Shukuri Mohamad; Leow, Thean Chor; Kamarudin, Nor Hafizah Ahmad; Masomian, Malihe; Rahman, Raja Noor Zaliha Raja Abd
2017-09-25
Less sedimentation and convection in a microgravity environment has become a well-suited condition for growing high quality protein crystals. Thermostable T1 lipase derived from bacterium Geobacillus zalihae has been crystallized using the counter diffusion method under space and earth conditions. Preliminary study using YASARA molecular modeling structure program for both structures showed differences in number of hydrogen bond, ionic interaction, and conformation. The space-grown crystal structure contains more hydrogen bonds as compared with the earth-grown crystal structure. A molecular dynamics simulation study was used to provide insight on the fluctuations and conformational changes of both T1 lipase structures. The analysis of root mean square deviation (RMSD), radius of gyration, and root mean square fluctuation (RMSF) showed that space-grown structure is more stable than the earth-grown structure. Space-structure also showed more hydrogen bonds and ion interactions compared to the earth-grown structure. Further analysis also revealed that the space-grown structure has long-lived interactions, hence it is considered as the more stable structure. This study provides the conformational dynamics of T1 lipase crystal structure grown in space and earth condition.
NASA Astrophysics Data System (ADS)
Kagoshima, Yasushi; Miyagawa, Takamasa; Kagawa, Saki; Takeda, Shingo; Takano, Hidekazu
2017-08-01
The intensity distribution in phase space of an X-ray synchrotron radiation beamline was measured using a pinhole camera method, in order to verify astigmatism compensation by a Fresnel zone plate focusing optical system. The beamline is equipped with a silicon double crystal monochromator. The beam size and divergence at an arbitrary distance were estimated. It was found that the virtual source point was largely different between the vertical and horizontal directions, which is probably caused by thermal distortion of the monochromator crystal. The result is consistent with our astigmatism compensation by inclining a Fresnel zone plate.
Solar energy concentrator system for crystal growth and zone refining in space
NASA Technical Reports Server (NTRS)
Mcdermit, J. H.
1975-01-01
The technological feasibility of using solar concentrators for crystal growth and zone refining in space has been performed. Previous studies of space-deployed solar concentrators were reviewed for their applicability to materials processing and a new state-of-the-art concentrator-receiver radiation analysis was developed. The radiation analysis is in the form of a general purpose computer program. It was concluded from this effort that the technology for fabricating, orbiting and deploying large solar concentrators has been developed. It was also concluded that the technological feasibility of space processing materials in the focal region of a solar concentrator depends primarily on two factors: (1) the ability of a solar concentrator to provide sufficient thermal energy for the process and (2) the ability of a solar concentrator to provide a thermal environment that is conductive to the processes of interest. The analysis indicate that solar concentrators can satisfactorily provide both of these factors.
Electrochemical deposition of silver crystals aboard Skylab 4
NASA Technical Reports Server (NTRS)
Grodzka, P. G.; Facemire, B. R.; Johnston, M. H.; Gates, D. W.
1976-01-01
Silver crystals were grown aboard Skylab 4 by an electro-chemical reaction and subsequently returned to earth for comparison with crystals grown at 1- and 5-g. Both the Skylab and earth-grown crystals show a variety of structures. Certain tendencies in structure dependency on gravity level, however, can be discerned. In addition, downward growing dendrite streamers; upward growing chunky crystal streamers; growth along an air/liquid interface; and ribbon, film, and fiber crystal habits were observed in experiments conducted on the ground with solutions of varying concentrations. It was also observed that the crystal structures of space and ground electro-deposited silver crystals were very similar to the structures of germanium selenide and germanium telluride crystals grown in space and on the ground by a vapor transport technique. Consideration of the data leads to the conclusions that: (1) the rate of electrochemical displacement of silver ions from a 5 percent aqueous solution by copper is predominantly diffussion controlled in space and kinetically controlled in 1- and higher-g because of augmentation of mass transport by convection; (2) downward and upward crystal streamers are the result of gravity-driven convection, the flow patterns of which can be delineated. Lateral growths along an air/liquid interface are the result of surface-tension-driven convection, the pattern of which also can be delineated; (3) electrolysis in space or low-g environments can produce either dendritic crystals with more perfect microcrystalline structures or massive, single crystals with fewer defects than those grown on ground or at higher g-levels. Ribbons or films of space-grown silicon crystals would find a ready market for electronic substrate and photocell applications. Space-grown dendritic, metal crystals present the possibility of unique catalysts. Large perfect crystals of various materials are desired for a number of electronic and optical applications; and (4) vapor transport growth of germanium selenide and germanium telluride is affected by convection mechanisms similar to the mechanisms hypothesized for the electrochemical deposition of silver crystals. Evidence and considerations leading to the preceding summaries and conclusions are presented. The implications of the findings and conclusions for technological applications are discussed, and recommendations for further experiments are presented.
Crystallization of human estrogenic 17β-hydroxysteroid dehydrogenase under microgravity
NASA Astrophysics Data System (ADS)
Zhu, Dao-Wei; Zhou, Ming; Mao, Ying; Labrie, Fernand; Lin, Sheng-Xiang
1995-11-01
Human 17β-hydroxysteroid dehydrogenase has been crystallized on the ground in the complex form with NADP + and a complete data set of the crystal was primarily collected at 2.9 Å [D.-W. Zhu, X. Lee, R. Breton, D. Ghosh, W. Pangborn, W.L. Duax and S.-X. Lin, J. Mol. Biol. 234 (1993) 242]. To eliminate multiseeding, formation of multicrystals and to obtain higher quality crystals, we carried out the crystallization aboard the Russian MIR space station and crystals were recovered in January, 1994. Crystals of the enzyme were formed in 9 of the total 12 sitting drops in the space mission, in the presence of NADP + or estradiol. This is a first attempt of crystallization of a membrane-associated protein under microgravity in the presence of a detergent. The space experiments showed better results in nucleation number, crystal size and morphology than the ground ones, obtaining crystals diffracting to resolutions between 2.5-2.7 Å. The too early ground mixing has limited a more important improvement of the crystallization.
NASA Technical Reports Server (NTRS)
Park, Yeonjoon (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)
2009-01-01
A method provides X-ray diffraction (XRD) data suitable for integral detection of a twin defect in a strained or lattice-matched epitaxial material made from components having crystal structures having symme try belonging to different space groups. The material is mounted in a n X-ray diffraction (XRD) system. In one embodiment, the XRD system's goniometer angle Omega is set equal to (Theta(sub B)-Beta) where The ta(sub B) is a Bragg angle for a designated crystal plane of the allo y that is disposed at a non-perpendicular orientation with respect to the {111) crystal plane, and Beta is the angle between the designate d crystal plane and a { 111 } crystal plane of one of the epitaxial components. The XRD system's detector angle is set equal to (Theta(su b B)+Beta). The material can be rotated through an angle of azimuthal rotation Phi about the axis aligned with the material. Using the det ector, the intensity of the X-ray diffraction is recorded at least at the angle at which the twin defect occurs.
Observation of a discrete time crystal
NASA Astrophysics Data System (ADS)
Zhang, J.; Hess, P. W.; Kyprianidis, A.; Becker, P.; Lee, A.; Smith, J.; Pagano, G.; Potirniche, I.-D.; Potter, A. C.; Vishwanath, A.; Yao, N. Y.; Monroe, C.
2017-03-01
Spontaneous symmetry breaking is a fundamental concept in many areas of physics, including cosmology, particle physics and condensed matter. An example is the breaking of spatial translational symmetry, which underlies the formation of crystals and the phase transition from liquid to solid. Using the analogy of crystals in space, the breaking of translational symmetry in time and the emergence of a ‘time crystal’ was recently proposed, but was later shown to be forbidden in thermal equilibrium. However, non-equilibrium Floquet systems, which are subject to a periodic drive, can exhibit persistent time correlations at an emergent subharmonic frequency. This new phase of matter has been dubbed a ‘discrete time crystal’. Here we present the experimental observation of a discrete time crystal, in an interacting spin chain of trapped atomic ions. We apply a periodic Hamiltonian to the system under many-body localization conditions, and observe a subharmonic temporal response that is robust to external perturbations. The observation of such a time crystal opens the door to the study of systems with long-range spatio-temporal correlations and novel phases of matter that emerge under intrinsically non-equilibrium conditions.
Rathee, Vikram; Krishnaswamy, Rema; Pal, Antara; Raghunathan, V. A.; Impéror-Clerc, Marianne; Pansu, Brigitte; Sood, A. K.
2013-01-01
We demonstrate a unique shear-induced crystallization phenomenon above the equilibrium freezing temperature in weakly swollen isotropic and lamellar mesophases with bilayers formed in a cationic-anionic mixed surfactant system. Synchrotron rheological X-ray diffraction study reveals the crystallization transition to be reversible under shear (i.e., on stopping the shear, the nonequilibrium crystalline phase melts back to the equilibrium mesophase). This is different from the shear-driven crystallization below , which is irreversible. Rheological optical observations show that the growth of the crystalline phase occurs through a preordering of the phase to an phase induced by shear flow, before the nucleation of the phase. Shear diagram of the phase constructed in the parameter space of shear rate vs. temperature exhibits and transitions above the equilibrium crystallization temperature , in addition to the irreversible shear-driven nucleation of in the phase below . In addition to revealing a unique class of nonequilibrium phase transition, the present study urges a unique approach toward understanding shear-induced phenomena in concentrated mesophases of mixed amphiphilic systems. PMID:23986497
First results from the PROTEIN experiment on board the International Space Station
NASA Astrophysics Data System (ADS)
Decanniere, Klaas; Potthast, Lothar; Pletser, Vladimir; Maes, Dominique; Otalora, Fermin; Gavira, Jose A.; Pati, Luis David; Lautenschlager, Peter; Bosch, Robert
On March 15 2009 Space Shuttle Discovery was launched, carrying the Process Unit of the Protein Crystallization Diagnostics Facility (PCDF) to the International Space Station. It contained the PROTEIN experiment, aiming at the in-situ observation of nucleation and crystal growth behaviour of proteins. After installation in the European Drawer Rack (EDR) and connection to the PCDF Electronics Unit, experiment runs were performed continuously for 4 months. It was the first time that protein crystallization experiments could be modified on-orbit in near real-time, based on data received on ground. The data included pseudo-dark field microscope images, interferograms, and Dynamic Light Scattering data. The Process Unit with space grown crystals was returned to ground on July 31 2009. Results for the model protein glucose isomerase (Glucy) from Streptomyces rubiginosus crystallized with ammonium sulfate will be reported concerning nucleation and the growth from Protein and Impurities Depletion Zones (PDZs). In addition, results of x-ray analyses for space-grown crystals will be given.
NASA Technical Reports Server (NTRS)
Ma, Nancy
2003-01-01
Alloyed semiconductor crystals, such as germanium-silicon (GeSi) and various II-VI alloyed crystals, are extremely important for optoelectronic devices. Currently, high-quality crystals of GeSi and of II-VI alloys can be grown by epitaxial processes, but the time required to grow a certain amount of single crystal is roughly 1,000 times longer than the time required for Bridgman growth from a melt. Recent rapid advances in optoelectronics have led to a great demand for more and larger crystals with fewer dislocations and other microdefects and with more uniform and controllable compositions. Currently, alloyed crystals grown by bulk methods have unacceptable levels of segregation in the composition of the crystal. Alloyed crystals are being grown by the Bridgman process in space in order to develop successful bulk-growth methods, with the hope that the technology will be equally successful on earth. Unfortunately some crystals grown in space still have unacceptable segregation, for example, due to residual accelerations. The application of a weak magnetic field during crystal growth in space may eliminate the undesirable segregation. Understanding and improving the bulk growth of alloyed semiconductors in microgravity is critically important. The purpose of this grant to to develop models of the unsteady species transport during the bulk growth of alloyed semiconductor crystals in the presence of a magnetic field in microgravity. The research supports experiments being conducted in the High Magnetic Field Solidification Facility at Marshall Space Flight Center (MSFC) and future experiments on the International Space Station.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Darone, Gregory M.; Hmiel, Benjamin; Zhang, Jiliang
Fifteen ternary rare-earth metal gallium silicides have been synthesized using molten Ga as a molten flux. They have been structurally characterized by single-crystal and powder X-ray diffraction to form with three different structures—the early to mid-late rare-earth metals RE=La–Nd, Sm, Gd–Ho, Yb and Y form compounds with empirical formulae RE(Ga xSi 1–x)₂ (0.38≤x≤0.63), which crystallize with the tetragonal α-ThSi₂ structure type (space group I4₁/amd, No. 141; Pearson symbol tI12). The compounds of the late rare-earth crystallize with the orthorhombic α-GdSi₂ structure type (space group Imma, No. 74; Pearson symbol oI12), with refined empirical formula REGa xSi 2–x–y (RE=Ho, Er, Tm;more » 0.33≤x≤0.40, 0.10≤y≤0.18). LuGa₀.₃₂₍₁₎Si₁.₄₃₍₁₎ crystallizes with the orthorhombic YbMn₀.₁₇Si₁.₈₃ structure type (space group Cmcm, No. 63; Pearson symbol oC24). Structural trends are reviewed and analyzed; the magnetic susceptibilities of the grown single-crystals are presented. - Graphical abstract: This article details the exploration of the RE–Ga–Si ternary system with the aim to systematically investigate the structural “boundaries” between the α-ThSi₂ and α-GdSi₂-type structures, and studies of the magnetic properties of the newly synthesized single-crystalline materials. Highlights: • Light rare-earth gallium silicides crystallize in α-ThSi₂ structure type. • Heavy rare-earth gallium silicides crystallize in α-GdSi₂ structure type. • LuGaSi crystallizes in a defect variant of the YbMn₀.₁₇Si₁.₈₃ structure type.« less
Crystal growth of device quality GaAs in space
NASA Technical Reports Server (NTRS)
Gatos, Harry C.; Lagowski, Jacek
1989-01-01
The program on Crystal Growth of Device Quality GaAs in Space was initiated in 1977. The initial stage covering 1977 to 1984 was devoted strictly to ground-based research. By 1985 the program had evolved into its next logical stage aimed at space growth experiments; however, since the Challenger disaster, the program has been maintained as a ground-based program awaiting activation of experimentation in space. The overall prgram has produced some 80 original scientific publications on GaAs crystal growth, crystal characterization, and new approaches to space processing. Publication completed in the last three years are listed. Their key results are outlined and discussed in the twelve publications included as part of the report.
Optical system for the Protein Crystallisation Diagnostics Facility (PCDF) on board the ISS
NASA Astrophysics Data System (ADS)
Joannes, Luc; Dupont, Olivier; Dewandel, Jean-Luc; Ligot, Renaud; Algrain, Hervé
2004-06-01
The Protein Crystallisation Diagnostic Facility (PCDF) is a multi-user facility to study the protein crystallisation under the conditions of micro-gravity onboard the International Space Station (ISS) Columbus facility. Large size protein crystals will growth under reduced gravity in thermally controlled reactors. A combination of diagnostic tools like video system, microscope, interferometer, and light scattering device shall help to understand the growth phenomena. Common methods of protein crystallisation shall be performed in PCDF: Dialysis where the protein solution and the salt solution are separated by a semi-permeable membrane. Extended Length Dialysis Batch where the saturation to get crystals is achieved by changing the concentration of the protein in the sample liquid. The overall ESA project is leaded by EADS Space Transportation, Friedrichshafen, Germany. Lambda-X is responsible for the Optical System (OS), with Verhaert Design and Development as sub-contractor for the mechanical design. The OS includes different compact parts: Original illumination systems based on LEDs of difference colours; Quantitative Mach-Zehnder interferometers to measure the concentration distribution around crystals; Imaging assemblies to visualize the protein volume with different field of views. The paper concentrates on the description of each part, and in particular on the imaging assembly which allow switching from one field of view to another by passive elements only.
NASA Astrophysics Data System (ADS)
Ansari, M. H.; Attarzadeh, M. A.; Nouh, M.; Karami, M. Amin
2018-01-01
In this paper, a physical platform is proposed to change the properties of phononic crystals in space and time in order to achieve nonreciprocal wave transmission. The utilization of magnetoelastic materials in elastic phononic systems is studied. Material properties of magnetoelastic materials change significantly with an external magnetic field. This property is used to design systems with a desired wave propagation pattern. The properties of the magnetoelastic medium are changed in a traveling wave pattern, which changes in both space and time. A phononic crystal with such a modulation exhibits one-way wave propagation behavior. An extended transfer matrix method (TMM) is developed to model a system with time varying properties. The stop band and the pass band of a reciprocal and a nonreciprocal bar are found using this method. The TMM is used to find the transfer function of a magnetoelastic bar. The obtained results match those obtained via the theoretical Floquet-Bloch approach and numerical simulations. It is shown that the stop band in the transfer function of a system with temporal varying property for the forward wave propagation is different from the same in the backward wave propagation. The proposed configuration enables the physical realization of a class of smart structures that incorporates nonreciprocal wave propagation.
Automated protein crystal growth facility
NASA Astrophysics Data System (ADS)
Donald, Stacey
A customer for the protein crystal growth facility fills the specially designed chamber with the correct solutions, fills the syringes with their quenching solutions, and submits the data needed for the proper growth of their crystal. To make sure that the chambers and syringes are filled correctly, a NASA representative may assist the customer. The data needed is the approximate growth time, the growth temperature, and the desired crystal size, but this data can be changed anytime from the ground, if needed. The chambers are gathered and placed into numbered slots in special drawers. Then, data is entered into a computer for each of the chambers. Technicians map out when each chamber's growth should be activated so that all of the chambers have enough time to grow. All of this data is up-linked to the space station when the previous growth session is over. Anti-vibrational containers need to be constructed for the high forces encountered during the lift off and the landing of the space shuttle, and though our team has not designed these containers, we do not feel that there is any reason why a suitable one could not be made. When the shuttle reaches the space station, an astronaut removes a drawer of quenched chambers from the growth facility and inserts a drawer of new chambers. All twelve of the drawers can be replaced in this fashion. The optical disks can also be removed this way. The old drawers are stored for the trip back to earth. Once inside the growth facility, a chamber is removed by the robot and placed in one of 144 active sites at a time previously picked by a technician. Growth begins when the chamber is inserted into an active site. Then, the sensing system starts to determine the size of the protein crystal. All during the crystal's growth, the customer can view the crystal and read all of the crystal's data, such as growth rate and crystal size. When the sensing system determines that the crystal has reached the predetermined size, the robot is told to pick up a syringe filled with the correct quenchant solution and inject it into the chamber to stop the crystal growth. The chamber is then removed from the active site and placed into its original storage slot.
Automated protein crystal growth facility
NASA Technical Reports Server (NTRS)
Donald, Stacey
1994-01-01
A customer for the protein crystal growth facility fills the specially designed chamber with the correct solutions, fills the syringes with their quenching solutions, and submits the data needed for the proper growth of their crystal. To make sure that the chambers and syringes are filled correctly, a NASA representative may assist the customer. The data needed is the approximate growth time, the growth temperature, and the desired crystal size, but this data can be changed anytime from the ground, if needed. The chambers are gathered and placed into numbered slots in special drawers. Then, data is entered into a computer for each of the chambers. Technicians map out when each chamber's growth should be activated so that all of the chambers have enough time to grow. All of this data is up-linked to the space station when the previous growth session is over. Anti-vibrational containers need to be constructed for the high forces encountered during the lift off and the landing of the space shuttle, and though our team has not designed these containers, we do not feel that there is any reason why a suitable one could not be made. When the shuttle reaches the space station, an astronaut removes a drawer of quenched chambers from the growth facility and inserts a drawer of new chambers. All twelve of the drawers can be replaced in this fashion. The optical disks can also be removed this way. The old drawers are stored for the trip back to earth. Once inside the growth facility, a chamber is removed by the robot and placed in one of 144 active sites at a time previously picked by a technician. Growth begins when the chamber is inserted into an active site. Then, the sensing system starts to determine the size of the protein crystal. All during the crystal's growth, the customer can view the crystal and read all of the crystal's data, such as growth rate and crystal size. When the sensing system determines that the crystal has reached the predetermined size, the robot is told to pick up a syringe filled with the correct quenchant solution and inject it into the chamber to stop the crystal growth. The chamber is then removed from the active site and placed into its original storage slot. Another chamber is then placed into the active site and the process is repeated in all of the active sites until all of the chambers have complted their growth. After ninety days (the scheduled time between shuttle visits), the crystal growth is completed, and the old drawers are replaced with new ones. Once the customer extracts the crystals, the chambers are retrieved for future customers.
Material Problems for High-Temperature, High-Power Space Energy-Conversion Systems.
1984-05-01
M. Takahashi, S. Nanamaku, and M. Kimura , "The growth of ferroelectric single crystal Sr 2 Mb2 0 7 by means of F.Z. technique," J. of Crystal Growth...Holsbeke, "Preparation and characterization of high purity vanadium by EBFZM," J. of Less Common Metals, Vol. 39, 7-16 (1975). 18. S. Takai and H. Kimura ... uranium system from room temperature to 900 0C. The composition of maximum hardness increased from 40 atomic percent (a/o) zirconium at room ’ 69
The control of float zone interfaces by the use of selected boundary conditions
NASA Technical Reports Server (NTRS)
Foster, L. M.; Mcintosh, J.
1983-01-01
The main goal of the float zone crystal growth project of NASA's Materials Processing in Space Program is to thoroughly understand the molten zone/freezing crystal system and all the mechanisms that govern this system. The surface boundary conditions required to give flat float zone solid melt interfaces were studied and computed. The results provide float zone furnace designers with better methods for controlling solid melt interface shapes and for computing thermal profiles and gradients. Documentation and a user's guide were provided for the computer software.
NASA Astrophysics Data System (ADS)
Fathima, K. Saiadali; Vasumathi, M.; Anitha, K.
2016-05-01
The novel organic material C20H21ClN2O was synthesized by One-Pot synthesis method and the single crystals were grown by slow evaporation solution growth technique. The crystal structure was elucidated by subjecting the grown crystals to the single crystal x-ray diffraction analysis and was refined by full matrix least-squares method to R=0.039 for 2746 reflections. Crystal system of the grown crystal was found to be monoclinic with the space group P21/a and a=9.196(4) Å, b=13.449(4) Å, c=14.818(4) Å, β= 101.542(3)°, V=1795.6(11) Å3 and Z=4. In this crystal structure, cyclooctanone prefers to reside in a chair-boat conformation. The structure is stabilized by attractive molecular force such as CH/π interaction called hydrophobic interaction.
Jaimohan, S. M.; Naresh, M. D.; Arumugam, V.; Mandal, A. B.
2009-01-01
Birds often show efficient oxygen management in order to meet the special demands of their metabolism. However, the structural studies of avian haemoglobins (Hbs) are inadequate for complete understanding of the mechanism involved. Towards this end, purification, crystallization and preliminary X-ray diffraction studies have been carried out for parakeet Hb. Parakeet Hb was crystallized as the met form in low-salt buffered conditions after extracting haemoglobin from crude blood by microcentrifugation and purifying the sample by column chromatography. Good-quality crystals were grown from 10% PEG 3350 and a crystal diffracted to about 2.8 Å resolution. Preliminary diffraction data showed that the Hb crystal belonged to the monoclinic system (space group C2), with unit-cell parameters a = 110.68, b = 64.27, c = 56.40 Å, β = 109.35°. Matthews volume analysis indicated that the crystals contained a half-tetramer in the asymmetric unit. PMID:19851014
Jaimohan, S M; Naresh, M D; Arumugam, V; Mandal, A B
2009-10-01
Birds often show efficient oxygen management in order to meet the special demands of their metabolism. However, the structural studies of avian haemoglobins (Hbs) are inadequate for complete understanding of the mechanism involved. Towards this end, purification, crystallization and preliminary X-ray diffraction studies have been carried out for parakeet Hb. Parakeet Hb was crystallized as the met form in low-salt buffered conditions after extracting haemoglobin from crude blood by microcentrifugation and purifying the sample by column chromatography. Good-quality crystals were grown from 10% PEG 3350 and a crystal diffracted to about 2.8 A resolution. Preliminary diffraction data showed that the Hb crystal belonged to the monoclinic system (space group C2), with unit-cell parameters a = 110.68, b = 64.27, c = 56.40 A, beta = 109.35 degrees . Matthews volume analysis indicated that the crystals contained a half-tetramer in the asymmetric unit.
Crystal structure and vibrational spectra of melaminium arsenate
NASA Astrophysics Data System (ADS)
Anbalagan, G.; Marchewka, M. K.; Pawlus, K.; Kanagathara, N.
2015-01-01
The crystals of the new melaminium arsenate (MAS) [C3H7N6+ṡH2AsO4-] were obtained by the slow evaporation of an aqueous solution at room temperature. Single crystal X-ray diffraction analysis reveals that the crystal belongs to triclinic system with centro symmetric space group P-1. The crystals are built up from single protonated melaminium residues and single dissociated arsenate H2AsO4- anions. The protonated melaminium ring is almost planar. A combination of ionic and donor-acceptor hydrogen-bond interactions linking together the melaminium and arsenate residues forms a three-dimensional network. Vibrational spectroscopic analysis is reported on the basis of FT-IR and FT-Raman spectra recorded at room temperature. Hydrogen bonded network present in the crystal gives notable vibrational effect. DSC has also been performed for the crystal shows no phase transition in the studied temperature range (113-293 K).
Sizing of colloidal particle and protein molecules in a hanging fluid drop
NASA Technical Reports Server (NTRS)
Ansari, Rafat R.; Suh, Kwang I.
1995-01-01
We report non-invasive particle size measurements of polystyrene latex colloidal particles and bovine serum albumin (BSA) protein molecules suspended in tiny hanging fluid drops of 30 micro-Liter volume using a newly designed fiber optic probe. The probe is based upon the principles of the technique of dynamic light scattering (DLS). The motivation for this work comes from growing protein crystals in outer space. Protein crystals have been grown previously in hanging drops in microgravity experiments on-board the space shuttle orbiter. However, obtaining quantitative information on nucleation and growth of the protein crystals in real time has always been a desired goal, but hitherto not achieved. Several protein researchers have shown interest in using DLS to monitor crystal growth process in a droplet, but elaborate instrumentation and optical alignment problems have made in-situ applications difficult. We demonstrate that such an experiment is now possible. Our system offers fast (5 seconds) determination of particle size, utilize safe levels of very low laser power (less than or equal to 0.2 mW), a small scattering volume (approximately 2 x 10(exp -5) cu mm) and high spatial coherence (Beta) values. This is a major step forward when compared to currently available DLS systems.
Crystalline structures of particles interacting through the harmonic-repulsive pair potential
NASA Astrophysics Data System (ADS)
Levashov, V. A.
2017-09-01
The behavior of identical particles interacting through the harmonic-repulsive pair potential has been studied in 3D using molecular dynamics simulations at a number of different densities. We found that at many densities, as the temperature of the systems decreases, the particles crystallize into complex structures whose formation has not been anticipated in previous studies on the harmonic-repulsive pair potential. In particular, at certain densities, crystallization into the structure I a 3 ¯ d (space group #230) with 16 particles in the unit cell occupying Wyckoff special positions (16b) was observed. This crystal structure has not been observed previously in experiments or in computer simulations of single component atomic or soft matter systems. At another density, we observed a liquid which is rather stable against crystallization. Yet, we observed crystallization of this liquid into the monoclinic C2/c (space group #15) structure with 32 particles in the unit cell occupying four different non-special Wyckoff (8f) sites. In this structure particles located at different Wyckoff sites have different energies. From the perspective of the local atomic environment, the organization of particles in this structure resembles the structure of some columnar quasicrystals. At a different value of the density, we did not observe crystallization at all despite rather long molecular dynamics runs. At two other densities, we observed the formation of the β S n distorted diamond structures instead of the expected diamond structure. Possibly, we also observed the formation of the R 3 ¯ c hexagonal lattice with 24 particles per unit cell occupying non-equivalent positions.
Grzywa, Maciej; Geßner, Christof; Denysenko, Dmytro; Bredenkötter, Björn; Gschwind, Fabienne; Fromm, Katharina M; Nitek, Wojciech; Klemm, Elias; Volkmer, Dirk
2013-05-21
The syntheses of H2-phbpz, [Cu2(phbpz)]·2DEF·MeOH (CFA-2) and [Ag2(phbpz)] (CFA-3) (H2-phbpz = 3,3',5,5'-tetraphenyl-1H,1'H-4,4'-bipyrazole) compounds and their crystal structures are described. The Cu(I) containing metal-organic framework CFA-2 crystallizes in the tetragonal crystal system, within space group I4(1)/a (no. 88) and the following unit cell parameters: a = 30.835(14), c = 29.306(7) Å, V = 27 865(19) Å(3). CFA-2 features a flexible 3-D three-connected two-fold interpenetrated porous structure constructed of triangular Cu(I) subunits. Upon exposure to different kinds of liquids (MeOH, EtOH, DMF, DEF) CFA-2 shows pronounced breathing effects. CFA-3 crystallizes in the monoclinic crystal system, within space group P2(1)/c (no. 14) and the following unit cell parameters: a = 16.3399(3), b = 32.7506(4), c = 16.2624(3) Å, β = 107.382(2)°, V = 8305.3(2) Å(3). In contrast to the former compound, CFA-3 features a layered 2-D three-connected structure constructed from triangular Ag(i) subunits. Both compounds are characterized by elemental and thermogravimetric analyses, single crystal structure analysis and X-ray powder diffraction, FTIR- and fluorescence spectroscopy. Preliminary results on oxygen activation in CFA-2 are presented and potential improvements in terms of framework robustness and catalytic efficiency are discussed.
NASA Technical Reports Server (NTRS)
McCubbin, F. M.
2017-01-01
Apatite [Ca5(PO4)3(F,Cl,OH)] is present in a wide range of planetary materials, and due to the presence of volatiles within its crystal structure (X-site), many recent studies have attempted to use apatite to constrain the volatile contents of planetary magmas and mantle sources [i.e., 1]. Experimental studies have investigated the apatite-melt partitioning behavior of F, Cl, and OH in basaltic systems [e.g., 2- 3], reporting that apatite-melt partitioning of volatiles is best described as exchange equilibria similar to Fe-Mg partitioning between olivine and silicate melt. However, exchange coefficients may vary as a function of temperature, pressure, melt composition, and/or oxygen fugacity. Furthermore, exchange coefficients may vary in portions of apatite compositional space where F, Cl, and OH do not mix ideally in apatite [3]. In these regions of ternary space, we anticipate that crystal chemistry could influence partitioning behavior. Consequently, we conducted experiments to investigate the effect of apatite crystal chemistry on apatite-melt partitioning of F, Cl, and OH.
NASA Astrophysics Data System (ADS)
Gong, Yun; Liu, Jinzhi; Tang, Wang; Hu, Changwen
2008-03-01
In the presence of N, N'-dimethyllformamide (DMF), two isostructural metal (II)-milrinone complexes formulated as M(C 12H 8N 3O) 2 (M = Co 1 and Ni 2) have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The two compounds crystallize in the tetragonal system, chiral space group P4 32 12. They exhibit similar two dimensional (2D) square grid-like framework, in which milrinone acts as a ditopic ligand with its terminal pyridine and intra-annular acylamide groups covalently bridging different metal centers. The intra-annular acylamide ligand shows a chelate-coordinated mode. Compounds 1 and 2 are stable under 200 °C. Compound 3 formulated as (C 12H 9N 3O) 4·H 2O was obtained in the presence of water, the water molecule in the structure leads to the racemization of compound 3 and it crystallizes in the monoclinic system, non-chiral space group P2 1/ c. Milrinone exhibits a keto-form in the three compounds and compounds 1- 3 exhibit different photoluminescence properties.
Silambarasan, A; Rajesh, P; Ramasamy, P
2015-01-05
The single crystal of guanidine carbonate doped nickel sulfate hexahydrate was grown from solution for ultraviolet filters. The single crystal XRD confirms that the grown single crystal belongs to the tetragonal system with the space group of P4₁2₁2. The crystallinity of the grown crystal was estimated by powder X-ray diffraction studies. The optical transmission and thermal stability of as-grown guanidine carbonate doped nickel sulfate single crystals have been studied. The optical transmission spectrum demonstrates the characteristics of ultraviolet filters. The TG/DTA studies confirm the thermal properties of grown crystals. Thermo-gravimetric analysis showed that the dehydration temperature of the guanidine carbonate doped nickel sulfate crystal is about 100 °C, which is much higher than that of pure nickel sulfate hexahydrate (NSH) crystals which is 72 °C. The growth behaviors and dislocation density were detected under the high resolution XRD and etching studies respectively. Copyright © 2014 Elsevier B.V. All rights reserved.
Pandi, P; Peramaiyan, G; Sudhahar, S; Chakkaravarthi, G; Mohan Kumar, R; Bhagavannarayana, G; Jayavel, R
2012-12-01
Picolinium maleate (PM), an organic material has been synthesised and single crystals were grown by slow evaporation technique. The structure of the grown crystal was elucidated by using single crystal X-ray diffraction analysis. PM crystal belongs to the monoclinic crystallographic system with space group P2(1)/c. The crystalline perfection of the grown crystals was analyzed by high-resolution X-ray diffraction rocking curve measurements. The presence of functional groups in PM was identified by FTIR and FT-NMR spectral analyses. Thermal behaviour and stability of picolinium maleate were studied by TGA/DTA analyses. UV-Vis spectral studies reveal that PM crystals are transparent in the wavelength region 327-1100 nm. The laser damage threshold value of PM crystal was found to be 4.3 GW/cm(2) using Nd:YAG laser. The Kurtz and Perry powder second harmonic generation technique confirms the nonlinear optical property of the grown crystal. Copyright © 2012 Elsevier B.V. All rights reserved.
Optical, mechanical and thermal behaviors of Nitrilotriacetic acid single crystal
NASA Astrophysics Data System (ADS)
Deepa, B.; Philominathan, P.
2017-11-01
An organic nonlinear single crystal of Nitrilotriacetic acid (NTAA) was grown for the first time by employing a simple slow evaporation technique. Single crystal X-ray diffraction (XRD) analysis reveals that the grown crystal belongs to the monoclinic system with noncentrosymmetric space group CC. Fourier transform infrared (FTIR) spectral study ascertains the presence of functional groups in NTAA. The molecular structure of the grown crystal was confirmed by Nuclear Magnetic Resonance (NMR) spectral analysis. The optical parameters such as transmittance, absorption coefficient and band gap were calculated from UV-Visible and fluorescence studies. Dielectric measurements were carried out for different frequency and temperature. The mechanical strength of the grown crystal was measured using Vickers microhardness test. The high thermal stability and the melting point of the grown crystal were also estimated using thermogravimetric (TGA) and differential thermal analyses (DTA). The confirmation of the grown crystals belonging to nonlinear optical crystals was performed by Kurtz-Perry technique and found as suitable candidate for optoelectronics applications.
NASA Technical Reports Server (NTRS)
Kundrot, Craig E.; Barnes, Cindy L.; Snell, Eddie H.; Achari, Aniruddha; Whitaker, Ann F. (Technical Monitor)
2001-01-01
We determined the room temperature 1.2 A structure of thaumatin using a crystal grown in the first protein crystallization experiment conducted aboard the International Space Station (ISS). The crystals were grown in the Enhanced Gaseous Nitrogen Dewar (EGN) developed by Alexander McPherson and co-workers. EGN transports frozen solutions contained in tygon tubing in a liquid nitrogen Dewar to ISS where the tubes then thaw. Batch, free interface diffusion (FID), or vapor diffusion crystallization occurs after thawing. EGN was flown to the ISS on STS-106 on September 8, 2000. This was a "risk mitigation" flight that tested EGN performance and the process of conducting experiments on ISS. We focused on how to map a hanging drop crystallization recipe to the EGN FID method. Thaumatin was chosen as the test system. Three series of crystallization recipes were set-up. Each series tested different volume ratios of protein-rich solution to precipitant-rich solution. The series differed from each other by fixing either the protein concentration or the amount of protein in the solutions. Upon return of the samples to Earth on October 24 by STS-92, bubbles that spanned the diameter of the tubing were observed in all tubes. Such bubbles interrupt liquid-liquid diffusion and force vapor diffusion equilibration to occur instead. Nonetheless, crystals grew in 9 of 30 tubes. Many large crystals were grown, the largest being 2.0 x 1.1 x 1.0 cubic mm. The largest crystal was used to collect data at room temperature on beamline 7-1 of the Stanford Synchrotron Radiation Source to a maximum resolution of 1.2 A. The structure was refined anisotropically using SHELX with a data to parameter ratio of 4.5 to give an R(sub factor) of 15.8% (R(sub free) = 18.2%) for ail reflections without generated hydrogens. This refinement is proceeding. Comparisons of this 1.2 A microgravity structure to previous reports of the thaumatin structure at 1.75 A and to ground control crystals will be presented.
Researcher Determining a Ruby Laser’s Effect on a Crystal
1965-05-21
National Aeronautics and Space Administration (NASA) Lewis Research Center researcher Americo Forestieri aims a ruby laser beam at a crystal to determine the effects of its radiation. Forestieri was a researcher in the Electric Component Experiment Section of the Space Power System Division. Lewis was in the midst of a long-term effort to develop methods of delivering electrical power to spacecraft using nuclear, solar, or electrochemical technologies. Ruby lasers contain a ruby crystal with mirrors on either side. The laser action is created when a high-intensity lamp shines around the ruby and excites the electrons in the ruby’s chromium atoms. After the excitation, the electrons emit their ruby-red light. The mirrors reflect some of this red light back and forth inside the ruby which causes other excited chromium atoms to produce additional red light. This continues until the light pulse reaches high power levels and consumes all of the energy stored in the crystal. Forestieri used optical absorption and electron paramagnetic resonance techniques to study the extent and manner in which the radiation interacted with the samples. He determined that individual bands were assigned to specific electronic transitions. He also studied the atomic changes in the ruby crystals after irradiation. He found that complex interactions depend on the crystal pretreatment, purity, and irradiation dose.
A study of crystal growth by solution technique. [triglycine sulfate single crystals
NASA Technical Reports Server (NTRS)
Lal, R. B.
1979-01-01
The advantages and mechanisms of crystal growth from solution are discussed as well as the effects of impurity adsorption on the kinetics of crystal growth. Uncertainities regarding crystal growth in a low gravity environment are examined. Single crystals of triglycine sulfate were grown using a low temperature solution technique. Small components were assembled and fabricated for future space flights. A space processing experiment proposal accepted by NASA for the Spacelab-3 mission is included.
Macromolecular crystallization in microgravity generated by a superconducting magnet.
Wakayama, N I; Yin, D C; Harata, K; Kiyoshi, T; Fujiwara, M; Tanimoto, Y
2006-09-01
About 30% of the protein crystals grown in space yield better X-ray diffraction data than the best crystals grown on the earth. The microgravity environments provided by the application of an upward magnetic force constitute excellent candidates for simulating the microgravity conditions in space. Here, we describe a method to control effective gravity and formation of protein crystals in various levels of effective gravity. Since 2002, the stable and long-time durable microgravity generated by a convenient type of superconducting magnet has been available for protein crystal growth. For the first time, protein crystals, orthorhombic lysozyme, were grown at microgravity on the earth, and it was proved that this microgravity improved the crystal quality effectively and reproducibly. The present method always accompanies a strong magnetic field, and the magnetic field itself seems to improve crystal quality. Microgravity is not always effective for improving crystal quality. When we applied this microgravity to the formation of cubic porcine insulin and tetragonal lysozyme crystals, we observed no dependence of effective gravity on crystal quality. Thus, this kind of test will be useful for selecting promising proteins prior to the space experiments. Finally, the microgravity generated by the magnet is compared with that in space, considering the cost, the quality of microgravity, experimental convenience, etc., and the future use of this microgravity for macromolecular crystal growth is discussed.
NASA Astrophysics Data System (ADS)
Serebryakov, Yu. A.; Prokhorov, I. A.; Vlasov, V. N.; Korobeynikova, E. N.; Zakharov, B. G.; Shul'pina, I. L.; Marchenko, M. P.; Fryazinov, I. V.
2007-06-01
Results of ground-based experiments on crystallization of gallium antimonide on the POLIZON facility carried out within the framework of space experiment preparation aboard FOTON satellite are submitted. Technical and technological opportunities of suppression of disturbing factors for improvement of quality of grown crystals in space are substantiated. Features of formation of concentration and structure inhomogeneities in GaSb:Si crystals grown under non-stationary and stationary convection conditions are investigated. Experimental data about structure and dopant distribution inhomogeneities are discussed taking into account results of numerical researches of GaSb:Si crystallization. Also earlier received results of modeling of GaSb:Te crystallization under close temperature conditions are used. Correlation between computational and experimental data is shown. The data on intensity of flows close to crystallization front are received at which non-stationary or stationary conditions of crystallization are realized. The forecast for space conditions is made. The influence of a rotating magnetic field on convection in melt for application in space experiment projected is investigated.
Recent progress in the NASA-Goddard Space Flight Center atomic hydrogen standards program
NASA Technical Reports Server (NTRS)
Reinhardt, V. S.
1981-01-01
At NASA Goddard Space Flight Center and through associated contractors, a broad spectrum of work is being carried out to develop improved hydrogen maser frequency standards for field use, improved experimental hydrogen maser frequency standards, and improved frequency and time distribution and measurement systems for hydrogen maser use. Recent progress in the following areas is reported: results on the Nr masers built by the Applied Physics Laboratory of Johns Hopkins University, the development of a low cost hydrogen maser at Goddard Space Flight Center, and work on a low noise phase comparison system and digitally phase locked crystal oscillator called the distribution and measurement system.
Crystallization and crystal manipulation of a steric chaperone in complex with its lipase substrate
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pauwels, Kris, E-mail: krpauwel@vub.ac.be; Loris, Remy; Vandenbussche, Guy
2005-08-01
Crystals of the lipase of B. glumae in complex with its specific foldase were obtained in two forms. Crystallization, crystal manipulation and preliminary X-ray diffraction analysis are described. Bacterial lipases that are secreted via the type II secretion pathway require a lipase-specific foldase in order to obtain their native and biologically active conformation in the periplasmic space. The lipase–foldase complex from Burkholderia glumae (319 and 333 residues, respectively) was crystallized in two crystal forms. One crystal form belongs to space group P3{sub 1}21 (P3{sub 2}21), with unit-cell parameters a = b = 122.3, c = 98.2 Å. A procedure ismore » presented which improved the diffraction of these crystals from ∼5 to 2.95 Å. For the second crystal form, which belonged to space group C2 with unit-cell parameters a = 183.0, b = 75.7, c = 116.6 Å, X-ray data were collected to 1.85 Å.« less
NASA Technical Reports Server (NTRS)
Herren, B.
1992-01-01
In collaboration with a medical researcher at the University of Alabama at Birmingham, NASA's Marshall Space Flight Center in Huntsville, Alabama, under the sponsorship of the Microgravity Science and Applications Division (MSAD) at NASA Headquarters, is continuing a series of space experiments in protein crystal growth which could lead to innovative new drugs as well as basic science data on protein molecular structures. From 1985 through 1992, Protein Crystal Growth (PCG) experiments will have been flown on the Space Shuttle a total of 14 times. The first four hand-held experiments were used to test hardware concepts; later flights incorporated these concepts for vapor diffusion protein crystal growth with temperature control. This article provides an overview of the PCG program: its evolution, objectives, and plans for future experiments on NASA's Space Shuttle and Space Station Freedom.
Application of X-ray topography to USSR and Russian space materials science
Shul’pina, I. L.; Prokhorov, I. A.; Serebryakov, Yu. A.; Bezbakh, I. Zh.
2016-01-01
The authors’ experience of the application of X-ray diffraction imaging in carrying out space technological experiments on semiconductor crystal growth for the former USSR and for Russia is reported, from the Apollo–Soyuz programme (1975) up to the present day. X-ray topography was applied to examine defects in crystals in order to obtain information on the crystallization conditions and also on their changes under the influence of factors of orbital flight in space vehicles. The data obtained have promoted a deeper understanding of the conditions and mechanisms of crystallization under both microgravity and terrestrial conditions, and have enabled the elaboration of terrestrial methods of highly perfect crystal growth. The use of X-ray topography in space materials science has enriched its methods in the field of digital image processing of growth striations and expanded its possibilities in investigating the inhomogeneity of crystals. PMID:27158506
Application of X-ray topography to USSR and Russian space materials science.
Shul'pina, I L; Prokhorov, I A; Serebryakov, Yu A; Bezbakh, I Zh
2016-05-01
The authors' experience of the application of X-ray diffraction imaging in carrying out space technological experiments on semiconductor crystal growth for the former USSR and for Russia is reported, from the Apollo-Soyuz programme (1975) up to the present day. X-ray topography was applied to examine defects in crystals in order to obtain information on the crystallization conditions and also on their changes under the influence of factors of orbital flight in space vehicles. The data obtained have promoted a deeper understanding of the conditions and mechanisms of crystallization under both microgravity and terrestrial conditions, and have enabled the elaboration of terrestrial methods of highly perfect crystal growth. The use of X-ray topography in space materials science has enriched its methods in the field of digital image processing of growth striations and expanded its possibilities in investigating the inhomogeneity of crystals.
NASA Technical Reports Server (NTRS)
Srinivas, R.; Hambright, G.; Ainsworth, M.; Fiske, M.; Schaefer, D.
1995-01-01
The Crystal Growth Furnace (CGF) is currently undergoing modifications and refurbishment and is currently undergoing modifications and refurbishment and is manifested to refly on the Second United States Microgravity Laboratory (USML-2) mission scheduled for launch in September 1995. The CGF was developed for the National Aeronautics and Space Administration (NASA) under the Microgravity Science and Applications Division (MSAD) programs at NASA Headquarters. The refurbishment and reflight program is being managed by the Marshall Space Flight Center (MSFC) in Huntsville, Alabama. Funding and program support for the CGF project is provided to MSFC by the office of Life and Microgravity Sciences and Applications at NASA Headquarters. This paper presents an overview of the CGF system configuration for the USML-2 mission, and provides a brief description of the planned on-orbit experiment operation.
Macromolecular crystal growing system
NASA Technical Reports Server (NTRS)
Snyder, Robert S. (Inventor); Herren, Blair J. (Inventor); Carter, Daniel C. (Inventor); Yost, Vaughn H. (Inventor); Bugg, Charles E. (Inventor); Delucas, Lawrence J. (Inventor); Suddath, Fred L. (Inventor)
1991-01-01
A macromolecular crystal growing system especially designed for growing crystals in the low gravity of space as well as the gravity of earth includes at least one tray assembly, a carrier assembly which receives the tray, and a refrigeration-incubation module in which the carrier assembly is received. The tray assembly includes a plurality of sealed chambers with a plastic syringe and a plug means for the double tip of the syringe provided therein. Ganging mechanisms operate the syringes and plugs simultaneously in a precise and smooth operation. Preferably, the tray assemblies are mounted on ball bearing slides for smooth operation in inserting and removing the tray assemblies into the carrier assembly. The plugging mechanism also includes a loading control mechanism. A mechanism for leaving a syringe unplugged is also provided.
Study of Fluid Experiment System (FES)/CAST/Holographic Ground System (HGS)
NASA Technical Reports Server (NTRS)
Workman, Gary L.; Cummings, Rick; Jones, Brian
1992-01-01
The use of holographic and schlieren optical techniques for studying the concentration gradients in solidification processes has been used by several investigators over the years. The HGS facility at MSFC has been primary resource in researching this capability. Consequently, scientific personnel have been able to utilize these techniques in both ground based research and in space experiments. An important event in the scientific utilization of the HGS facilities was the TGS Crystal Growth and the casting and solidification technology (CAST) experiments that were flown on the International Microgravity Laboratory (IML) mission in March of this year. The preparation and processing of these space observations are the primary experiments reported in this work. This project provides some ground-based studies to optimize on the holographic techniques used to acquire information about the crystal growth processes flown on IML. Since the ground-based studies will be compared with the space-based experimental results, it is necessary to conduct sufficient ground based studies to best determine how the experiment worked in space. The current capabilities in computer based systems for image processing and numerical computation have certainly assisted in those efforts. As anticipated, this study has certainly shown that these advanced computing capabilities are helpful in the data analysis of such experiments.
Crystallization dynamics on curved surfaces
NASA Astrophysics Data System (ADS)
García, Nicolás A.; Register, Richard A.; Vega, Daniel A.; Gómez, Leopoldo R.
2013-07-01
We study the evolution from a liquid to a crystal phase in two-dimensional curved space. At early times, while crystal seeds grow preferentially in regions of low curvature, the lattice frustration produced in regions with high curvature is rapidly relaxed through isolated defects. Further relaxation involves a mechanism of crystal growth and defect annihilation where regions with high curvature act as sinks for the diffusion of domain walls. The pinning of grain boundaries at regions of low curvature leads to the formation of a metastable structure of defects, characterized by asymptotically slow dynamics of ordering and activation energies dictated by the largest curvatures of the system. These glassylike ordering dynamics may completely inhibit the appearance of the ground-state structures.
Mahadevan, M; Ramachandran, K; Anandan, P; Arivanandhan, M; Bhagavannarayana, G; Hayakawa, Y
2014-12-10
Single crystals of l-arginine 4-nitrophenolate 4-nitrophenol dihydrate (LAPP) have been grown successfully from the solution of l-arginine and 4-nitrophenol. Slow evaporation of solvent technique was adopted to grow the bulk single crystals. Single crystal X-ray diffraction analysis confirms the grown crystal has monoclinic crystal system with space group of P21. Powder X-ray diffraction analysis shows the good crystalline nature. The crystalline perfection of the grown single crystals was analyzed by HRXRD by employing a multicrystal X-ray diffractometer. The functional groups were identified from proton NMR spectroscopic analysis. Linear and nonlinear optical properties were determined by UV-Vis spectrophotometer and Kurtz powder technique respectively. It is found that the grown crystal has no absorption in the green wavelength region and the SHG efficiency was found to be 2.66 times that of the standard KDP. The Thermal stability of the crystal was found by obtaining TG/DTA curve. The mechanical behavior of the grown crystal has been studied by Vicker's microhardness method. Copyright © 2014 Elsevier B.V. All rights reserved.
Liquid drop stability for protein crystal growth in microgravity
NASA Technical Reports Server (NTRS)
Owen, Robert B.; Broom, Beth H.; Snyder, Robert S.; Daniel, Ron
1987-01-01
It is possible to grow protein crystals for biomedical research in microgravity by deploying a protein-rich solution from a syringe, forming a drop in which crystallization can occur with the proper degree of supersaturation. Drop stability is critical to the success of this research, due to the large drop sizes which can be achieved in space. In order to determine the type of syringe tips most suitable to support these large drops, tests were performed during brief periods of weightlessness onboard the NASA KC-135 low-gravity simulation aircraft. The drops were analyzed using three simple models in which the samples were approximated by modified pendulum and spring systems. It was concluded that the higher frequency systems were the most stable, indicating that of the syringes utilized, a disk-shaped configuration provided the most stable environment of low-gravity protein crystal growth.
NASA Technical Reports Server (NTRS)
Steiner, Bruce; Dobbyn, Ronald C.; Black, David; Burdette, Harold; Kuriyama, Masao; Fripp, Archibald; Simchik, Richard
1991-01-01
Irregularities in three crystals grown in space and in four terrestrial crystals grown under otherwise comparable conditions have been observed in high resolution diffraction imaging. The images provide important new clues to the nature and origins of irregularities in each crystal. For two of the materials, mercuric iodide and lead tin telluride, more than one phase (an array of non-diffracting inclusions) was observed in terrestrial samples; but the formation of these multiple phases appears to have been suppressed in directly comparable crystals grown in microgravity. The terrestrial seed crystal of triglycine sulfate displayed an unexpected layered structure, which propagated during directly comparable space growth. Terrestrial Bridgman regrowth of gallium arsenide revealed a mesoscopic structure substantially different from that of the original Czochralski material. A directly comparable crystal is to be grown shortly in space.
The application and use of chemical space mapping to interpret crystallization screening results
Snell, Edward H.; Nagel, Ray M.; Wojtaszcyk, Ann; O’Neill, Hugh; Wolfley, Jennifer L.; Luft, Joseph R.
2008-01-01
Macromolecular crystallization screening is an empirical process. It often begins by setting up experiments with a number of chemically diverse cocktails designed to sample chemical space known to promote crystallization. Where a potential crystal is seen a refined screen is set up, optimizing around that condition. By using an incomplete factorial sampling of chemical space to formulate the cocktails and presenting the results graphically, it is possible to readily identify trends relevant to crystallization, coarsely sample the phase diagram and help guide the optimization process. In this paper, chemical space mapping is applied to both single macromolecules and to a diverse set of macromolecules in order to illustrate how visual information is more readily understood and assimilated than the same information presented textually. PMID:19018100
The application and use of chemical space mapping to interpret crystallization screening results.
Snell, Edward H; Nagel, Ray M; Wojtaszcyk, Ann; O'Neill, Hugh; Wolfley, Jennifer L; Luft, Joseph R
2008-12-01
Macromolecular crystallization screening is an empirical process. It often begins by setting up experiments with a number of chemically diverse cocktails designed to sample chemical space known to promote crystallization. Where a potential crystal is seen a refined screen is set up, optimizing around that condition. By using an incomplete factorial sampling of chemical space to formulate the cocktails and presenting the results graphically, it is possible to readily identify trends relevant to crystallization, coarsely sample the phase diagram and help guide the optimization process. In this paper, chemical space mapping is applied to both single macromolecules and to a diverse set of macromolecules in order to illustrate how visual information is more readily understood and assimilated than the same information presented textually.
Gosenca, Mirjam; Bešter-Rogač, Marija; Gašperlin, Mirjana
2013-09-27
Liquid crystalline systems with a lamellar structure have been extensively studied as dermal delivery systems. Ascorbyl palmitate (AP) is one of the most studied and used ascorbic acid derivatives and is employed as an antioxidant to prevent skin aging. The aim of this study was to develop and characterize skin-compliant dermal delivery systems with a liquid crystalline structure for AP. First, a pseudoternary phase diagram was constructed using Tween 80/lecithin/isopropyl myristate/water at a Tween 80/lecithin mass ratio of 1/1, and the region of lamellar liquid crystals was identified. Second, selected unloaded and AP-loaded lamellar liquid crystal systems were physicochemically characterized with polarizing optical microscopy, small-angle X-ray scattering, differential scanning calorimetry, and rheology techniques. The interlayer spacing and rheological parameters differ regarding quantitative composition, whereas the microstructure of the lamellar phase was affected by the AP incorporation, resulting either in additional micellar structures (at 25 and 32 °C) or being completely destroyed at higher temperature (37°C). After this, the study was oriented towards in vitro cytotoxicity evaluation of lamellar liquid crystal systems on a keratinocyte cell line. The results suggest that the lamellar liquid crystals that were developed could be used as a physiologically acceptable dermal delivery system. Copyright © 2013 Elsevier B.V. All rights reserved.
Protein-Precipitant-Specific Criteria for the Impact of Reduced Gravity on Crystal Perfection
NASA Technical Reports Server (NTRS)
Vekilov, Peter G.; Witherow, W. (Technical Monitor)
2003-01-01
The objective of this research is to provide quantitative criteria for the impact of reduced or enhanced convective transport on protein crystal perfection. Our earlier work strongly suggests that the magnitude of (lattice defect-inducing) fluctuations in the crystallization rate of proteins arise from the coupling of bulk transport and nonlinear interface kinetics. Hence, we surmised that, depending on the relative weight of bulk transport and interface kinetics in the control of the crystallization process on Earth, these fluctuations can either increase or decrease under reduced gravity conditions. The sign and magnitude of these changes depend on the specific protein-precipitant system. As a consequence, space environments can be either beneficial or detrimental for achieving structural perfection in protein crystals. The task objectives consist in systematic investigations of this hypothesis.
Comparative Analysis of Thaumatin Crystals Grown on Earth and in Microgravity. Experiment 23
NASA Technical Reports Server (NTRS)
Ng, Joseph D.; Lorber, Bernard; Giege, Richard; Koszelak, Stanley; Day, John; Greenwood, Aaron; McPherson, Alexander
1998-01-01
The protein thaumatin was studied as a model macromolecule for crystallization in microgravity environment experiments conducted on two U.S. Space Shuttle missions (second United States Microgravity Laboratory (USML-2) and Life and Microgravity Spacelab (LMS)). In this investigation we evaluated and compared the quality of space- and Earth-grown thaumatin crystals using x-ray diffraction analysis and characterized them according to crystal size, diffraction resolution limit, and mosaicity. Two different approaches for growing thaumatin crystals in the microgravity environment, dialysis and liquid-liquid diffusion, were employed as a joint experiment by our two investigative teams. Thaumatin crystals grown under a microgravity environment were generally larger in volume with fewer total crystals. They diffracted to significantly higher resolution and with improved diffraction properties as judged by relative Wilson plots. The mosaicity for space-grown crystals was significantly less than for those grown on Earth. Increasing concentrations of protein in the crystallization chambers under microgravity lead to larger crystals. The data presented here lend further support to the idea that protein crystals of improved quality can be obtained in a microgravity environment.
Video-Growing Salt Crystals Onboard the International Space Station (ISS)
NASA Technical Reports Server (NTRS)
2003-01-01
Saturday Morning Science, the science of opportunity series of applied experiments and demonstrations, performed aboard the International Space Station (ISS) by Expedition 6 astronaut Dr. Don Pettit, revealed some remarkable findings. Growing salt crystals in a bottle of water is a favorite science activity for kids. In space, Dr. Pettit grew salt crystals in stretched films of water so that the salt water only fed the crystals around the edges rather than from all sides, as happens in a glass of water. This video of his demonstration shows that surface tension plays a surprisingly dominant role in the crystal formation and convection is more active that one might expect.
Center for the development of commercial crystal growth in space
NASA Technical Reports Server (NTRS)
Wilcox, William R.
1989-01-01
The second year of operation of the Center for Commercial Crystal Growth in Space is described. This center is a consortium of businesses, universities and national laboratories. The primary goal of the Center's research is the development of commercial crystal growth in space. A secondary goal is to develop scientific understanding and technology which will improve commercial crystal growth on earth. In order to achieve these goals the Center's research is organized into teams by growth technique; melt growth, solution growth, and vapor growth. The melt growth team is working on solidification and characterization of bulk crystals of gallium arsenide and cadmium telluride. They used high resolution X-ray topography performed at the National Synchrotron Light Source at Brookhaven National Laboratory. Streak-like features were found in the diffraction images of semi-insulating undoped LEC GaAs. These were shown to be (110) antiphase boundaries, which have not been reported before but appear to be pervasive and responsible for features seen via less-sensitive characterization methods. The results on CdTe were not as definitive, but indicate that antiphase boundaries may also be responsible for the double peaks often seen in X-ray rocking curves of this material. A liquid encapsulated melt zone system for GaAs has been assembled and techniques for casting feed rods developed. It was found that scratching the inside of the quartz ampoules with silicon carbide abrasive minimized sticking of the GaAs to the quartz. Twelve floating zone experiments were done.
Synthesis and structural study of N-isopropenylbenzimidazolone
NASA Astrophysics Data System (ADS)
Mondieig, D.; Negrier, Ph.; Leger, J. M.; Lakhrissi, L.; El Assyry, A.; Lakhrissi, B.; Essassi, E. M.; Benali, B.; Boucetta, A.
2015-05-01
The synthesis and the crystal structure of the N-isopropenylbenzimidazolone (C10H10N2O) are presented. The synthesis was performed by Meth-Cohen method by reaction of o-phenylenediamine with ethyl acetoacetate in refluxed xylene. The single crystal structure was determined at room temperature by means of X-rays diffraction. The crystal system is monoclinic, with space group C2/c and eight molecules per unit cell. The unit cell dimensions are: a = 15.978(1) Å, b = 6.100(2) Å, c = 18.222(2) Å, β = 90.16(1)° and V = 1776.0(6) Å3.
International Space Station (ISS)
2002-07-05
Expedition Five flight engineer Peggy Whitson is shown installing the Solidification Using a Baffle in Sealed Ampoules (SUBSA) experiment in the Microgravity Science Glovebox (MSG) in the Destiny laboratory aboard the International Space Station (ISS). SUBSA examines the solidification of semiconductor crystals from a melted material. Semiconductor crystals are used for many products that touch our everyday lives. They are found in computer chips, integrated circuits, and a multitude of other electronic devices, such as sensors for medical imaging equipment and detectors of nuclear radiation. Materials scientists want to make better semiconductor crystals to be able to further reduce the size of high-tech devices. In the microgravity environment, convection and sedimentation are reduced, so fluids do not remove and deform. Thus, space laboratories provide an ideal environment of studying solidification from the melt. This investigation is expected to determine the mechanism causing fluid motion during production of semiconductors in space. It will provide insight into the role of the melt motion in production of semiconductor crystals, advancing our knowledge of the crystal growth process. This could lead to a reduction of defects in semiconductor crystals produced in space and on Earth.
Developments in the Implementation of Acoustic Droplet Ejection for Protein Crystallography.
Wu, Ping; Noland, Cameron; Ultsch, Mark; Edwards, Bonnie; Harris, David; Mayer, Robert; Harris, Seth F
2016-02-01
Acoustic droplet ejection (ADE) enables crystallization experiments at the low-nanoliter scale, resulting in rapid vapor diffusion equilibration dynamics and efficient reagent usage in the empirical discovery of structure-enabling protein crystallization conditions. We extend our validation of this technology applied to the diverse physicochemical property space of aqueous crystallization reagents where dynamic fluid analysis coupled to ADE aids in accurate and precise dispensations. Addition of crystallization seed stocks, chemical additives, or small-molecule ligands effectively modulates crystallization, and we here provide examples in optimization of crystal morphology and diffraction quality by the acoustic delivery of ultra-small volumes of these cofactors. Additional applications are discussed, including set up of in situ proteolysis and alternate geometries of crystallization that leverage the small scale afforded by acoustic delivery. Finally, we describe parameters of a system of automation in which the acoustic liquid handler is integrated with a robotic arm, plate centrifuge, peeler, sealer, and stacks, which allows unattended high-throughput crystallization experimentation. © 2015 Society for Laboratory Automation and Screening.
NASA Astrophysics Data System (ADS)
Menezes, Anthoni Praveen; Jayarama, A.; Ng, Seik Weng
2015-05-01
An efficient nonlinear optical material 2E-3-(4-bromophenyl)-1-(pyridin-3-yl) prop-2-en-1-one (BPP) was synthesized and single crystals were grown using slow evaporation solution growth technique at room temperature. Grown crystal had prismatic morphology and its structure was confirmed by various spectroscopic studies, elemental analysis, and single crystal X-ray diffraction (XRD) technique. The single crystal XRD of the crystal showed that BPP crystallizes in monoclinic system with noncentrosymmetric space group P21 and the cell parameters are a = 5.6428(7) Å, b = 3.8637(6) Å, c = 26.411(2) Å, β = 97.568(11) deg and v = 575.82(12) Å3. The UV-Visible spectrum reveals that the crystal is optically transparent and has high optical energy band gap of 3.1 eV. The powder second harmonic generation efficiency (SHG) of BPP is 6.8 times that of KDP. From thermal analysis it is found that the crystal melts at 139 °C and decomposes at 264 °C. High optical transparency down to blue region, higher powder SHG efficiency and better thermal stability than that of urea makes this chalcone derivative a promising candidate for SHG applications. Furthermore, effect of molecular planarity on SHG efficiency and role of pyridine ring adjacent to carbonyl group in forming noncentrosymmetric crystal systems of chalcone family is also discussed.
Kinetics of Nucleation and Crystal Growth in Glass Forming Melts in Microgravity
NASA Technical Reports Server (NTRS)
Day, Delbert E.; Ray, Chandra S.
1999-01-01
The following list summarizes the most important results that have been consistently reported for glass forming melts in microgravity: (1) Glass formation is enhanced for melts prepared in space; (2) Glasses prepared in microgravity are more chemically homogeneous and contain fewer and smaller chemically heterogeneous regions than identical glasses prepared on earth; (3) Heterogeneities that are deliberately introduced such as Pt particles are more uniformly distributed in a glass melted in space than in a glass melted on earth; (4) Glasses prepared in microgravity are more resistant to crystallization and have a higher mechanical strength and threshold energy for radiation damage; and (5) Glasses crystallized in space have a different microstructure, finer grains more uniformly distributed, than equivalent samples crystallized on earth. The preceding results are not only scientifically interesting, but they have considerable practical implications. These results suggest that the microgravity environment is advantageous for developing new and improved glasses and glass-ceramics that are difficult to prepare on earth. However, there is no suitable explanation at this time for why a glass melted in microgravity will be more chemically homogeneous and more resistant to crystallization than a glass melted on earth. A fundamental investigation of melt homogenization, nucleation, and crystal growth processes in glass forming melts in microgravity is important to understanding these consistently observed, but yet unexplained results. This is the objective of the present research. A lithium disilicate (Li2O.2SiO2) glass will be used for this investigation, since it is a well studied system, and the relevant thermodynamic and kinetic parameters for nucleation and crystal growth at 1-g are available. The results from this research are expected to improve our present understanding of the fundamental mechanism of nucleation and crystal growth in melts and liquids, and to lead improvements in glass processing technology on earth, with the potential for creating new high performance glasses and glass-ceramics.
Protein Crystal Quality Studies
NASA Technical Reports Server (NTRS)
1998-01-01
Eddie Snell (standing), Post-Doctoral Fellow the National Research Council (NRC),and Marc Pusey of Marshall Space Flight Center (MSFC) use a reciprocal space mapping diffractometer for marcromolecular crystal quality studies. The diffractometer is used in mapping the structure of marcromolecules such as proteins to determine their structure and thus understand how they function with other proteins in the body. This is one of several analytical tools used on proteins crystalized on Earth and in space experiments. Photo credit: NASA/Marshall Space Flight Center (MSFC)
Subbarao, Udumula; Rayaprol, Sudhindra; Dally, Rebecca; Graf, Michael J; Peter, Sebastian C
2016-01-19
The compounds RECuGa3 (RE = La-Nd, Sm-Gd) were synthesized by various techniques. Preliminary X-ray diffraction (XRD) analyses at room temperature suggested that the compounds crystallize in the tetragonal system with either the centrosymmetric space group I4/mmm (BaAl4 type) or the non-centrosymmetric space group I4mm (BaNiSn3 type). Detailed single-crystal XRD, neutron diffraction, and synchrotron XRD studies of selected compounds confirmed the non-centrosymmetric BaNiSn3 structure type at room temperature with space group I4mm. Temperature-dependent single-crystal XRD, powder XRD, and synchrotron beamline measurements showed a structural transition between centro- and non-centrosymmetry followed by a phase transition to the Rb5Hg19 type (space group I4/m) above 400 K and another transition to the Cu3Au structure type (space group Pm3̅m) above 700 K. Combined single-crystal and synchrotron powder XRD studies of PrCuGa3 at high temperatures revealed structural transitions at higher temperatures, highlighting the closeness of the BaNiSn3 structure to other structure types not known to the RECuGa3 family. The crystal structure of RECuGa3 is composed of eight capped hexagonal prism cages [RE4Cu4Ga12] occupying one rare-earth atom in each ring, which are shared through the edge of Cu and Ga atoms along the ab plane, resulting in a three-dimensional network. Resistivity and magnetization measurements demonstrated that all of these compounds undergo magnetic ordering at temperatures between 1.8 and 80 K, apart from the Pr and La compounds: the former remains paramagnetic down to 0.3 K, while superconductivity was observed in the La compound at T = 1 K. It is not clear whether this is intrinsic or due to filamentary Ga present in the sample. The divalent nature of Eu in EuCuGa3 was confirmed by magnetization measurements and X-ray absorption near edge spectroscopy and is further supported by the crystal structure analysis.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xie, Wei; Schimmel, Paul; Yang, Xiang-Lei, E-mail: xlyang@scripps.edu
2006-12-01
Crystallization and preliminary X-ray analysis of a native human tRNA synthetase whose allelic variants are associated with Charcot–Marie–Tooth Disease. Glycyl-tRNA synthetase (GlyRS) is one of a group of enzymes that catalyze the synthesis of aminoacyl-tRNAs for translation. Mutations of human and mouse GlyRSs are causally associated with Charcot–Marie–Tooth disease, the most common genetic disorder of the peripheral nervous system. As the first step towards a structure–function analysis of this disease, native human GlyRS was expressed, purified and crystallized. The crystal belonged to space group P4{sub 3}2{sub 1}2 or its enantiomorphic space group P4{sub 1}2{sub 1}2, with unit-cell parameters a =more » b = 91.74, c = 247.18 Å, and diffracted X-rays to 3.0 Å resolution. The asymmetric unit contained one GlyRS molecule and had a solvent content of 69%.« less
NASA Astrophysics Data System (ADS)
Sujatha, T.; Cyrac Peter, A.; Vimalan, M.; Merline Shyla, J.; Madhavan, J.
2010-08-01
An efficient, novel, semi-organic, nonlinear optical (NLO) material L-phenylalanine L-phenylalaninium dihydrogenphosphate (LPADHP), single crystal of dimension 11×5×2 mm 3, has been grown by the slow evaporation solution growth technique. Single crystal X-ray diffraction studies confirm that the grown crystal belongs to monoclinic system with the space group P2 1. The functional groups present in the crystal were confirmed by the Fourier transform infrared technique. Optical absorption spectrum shows that the material possesses very low absorption in the entire visible region. Thermal analysis confirmed that the crystal is thermally stable up to 161 °C. The frequency dependent dielectric properties of the grown crystal were studied for various temperatures. The second harmonic generation (SHG) efficiency of the grown crystal is 1.2 times greater than that of the potassium dihydrogenphosphate (KDP) single crystal. The laser induced surface damage threshold for the grown crystal was found to be 6.3 GW cm -2 with Nd:YAG laser assembly AC and DC conductivity and photoconductivity experiments are also carried out and the results are discussed.
NASA Astrophysics Data System (ADS)
Drozd, Marek; Daszkiewicz, Marek
2018-06-01
According to literature data the two crystals are known: guanidinium m-nitrobenzoate and guanidinium p-nitrobenzoate. Both compounds belong to noncetrosymmetric crystallographic systems are consider as second order generators in nonlinear optic (NLO). For each of these crystals the detailed crystallographic, theoretical calculations and vibrational studies were performed. It is interesting that nitrobenzoic acid create tree variety of compounds ((2) ortho-, (3) meta- and (4) para-) what any data for third member of guanidinium nitrobenzoate crystal were not known. The guanidinium o-nitrobenzoate hydrate crystal was synthesized first time. The performed X-ray crystallographic study shown that crystal belongs to space group without macroscopic symmetry center. Additionally, the vibrational spectra (intensities, frequencies and PED analysis) of investigated compound are presented. These results are compared with theoretical calculations for equilibrium geometry and vibrational properties. Furthermore, the results of the theoretical approach include HOMO and LUMO energies and first order hyperpolarizability were obtained, also. On the basis of these data the crystal was classified as second order generator. All obtained results are compared with previous literature data of guanidinium m-nitrobenzoate and guanidinium p-nitrobenzoate compounds. Surprisingly, each of examined crystal belongs to different crystallographic system and shows different vibrational properties.
STS-62 Space Shuttle mission report
NASA Technical Reports Server (NTRS)
Fricke, Robert W., Jr.
1994-01-01
The STS-62 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSHE) systems performance during the sixty-first flight of the Space Shuttle Program and sixteenth flight of the Orbiter vehicle Columbia (OV-102). In addition to the Orbiter, the flight vehicle consisted of an ET designated as ET-62; three SSME's which were designated as serial numbers 2031, 2109, and 2029 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-064. The RSRM's that were installed in each SRB were designated as 360L036A (lightweight) for the left SRB, and 36OWO36B (welterweight) for the right SRB. This STS-62 Space Shuttle Program Mission Report fulfills the Space Shuttle Program requirement as documented in NSTS 07700, Volume 8, Appendix E. That document requires that each major organizational element supporting the Program report the results of its hardware evaluation and mission performance plus identify all related in-flight anomalies. The primary objectives of the STS-62 mission were to perform the operations of the United States Microgravity Payload-2 (USMP-2) and the Office of Aeronautics and Space Technology-2 (OAST-2) payload. The secondary objectives of this flight were to perform the operations of the Dexterous End Effector (DEE), the Shuttle Solar Backscatter Ultraviolet/A (SSBUV/A), the Limited Duration Space Environment Candidate Material Exposure (LDCE), the Advanced Protein Crystal Growth (APCG), the Physiological Systems Experiments (PSE), the Commercial Protein Crystal Growth (CPCG), the Commercial Generic Bioprocessing Apparatus (CGBA), the Middeck Zero-Gravity Dynamics Experiment (MODE), the Bioreactor Demonstration System (BDS), the Air Force Maui Optical Site Calibration Test (AMOS), and the Auroral Photography Experiment (APE-B).
Very High Quality Crystals of Wide-Gap II-VI Semiconductors: What for?
2001-01-01
the reciprocal space mapping , by the etch pit density (EPD) measurements (to determine the density of dislocations) and by the measurement of the width...crystals. The EPD was in the range 5 x 1 + 104 cmn2 for Cdl.,ZnxTe crystals and about 104 cmz for ZnTe. The reciprocal space mapping of the crystals
Optical characteristics of novel bulk and nanoengineered laser host materials
NASA Astrophysics Data System (ADS)
Prasad, Narasimha S.; Sova, Stacey; Kelly, Lisa; Bevan, Talon; Arnold, Bradley; Cooper, Christopher; Choa, Fow-Sen; Singh, N. B.
2018-02-01
The hexagonal apatite single crystals have been investigated for their applications as laser host materials. Czochralksi and flux growth methods have been utilized to obtain single crystals. For low temperature processing (<100 0C), several techniques for crystal growth have been developed. The hexagonal apatite structure (space group P63/m) is characteristic of several compounds, some of which have extremely interesting and useful properties as laser hosts and bone materials. Calcium lanthanum silicate (Nd-doped) and lanthanum aluminate material systems were studied in detail. Nanoengineered calcium and lanthanum based silicates were synthesized by a solution method and their optical and morphological characteristics were compared with Czochralski grown bulk hydroxyapatite single crystals. Materials were evaluated by absorbance, fluorescence and Raman characteristics. Neodymium, iron and chromium doped crystals grown by a solution method showed weak but similar optical properties to that of Czochralski grown single crystals.
Allouchi, H; Céolin, R; Berthon, L; Tombret, F; Rietveld, I B
2014-07-01
The crystal structure of L-ornithinium α-ketoglutarate (C5H13N2O2, C5H5O5) has been solved by direct methods using single crystal X-ray diffraction data. It crystallizes in the monoclinic system, space group P21, unit cell parameters a=15.4326(3), b=5.2015(1), c=16.2067(3) Å and β=91.986(1)°, containing two independent pairs of molecular ions in the asymmetric unit. An extensive hydrogen-bond network and electrostatic charges due to proton transfer provide an important part of the cohesive energy of the crystal. The conformational versatility of L-ornithine and α-ketoglutaric acid is illustrated by the present results and crystal structures available from the Cambridge Structural Database. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
In-Situ Optical Determination of Thermomechanical Properties of ZnSe and ZnTe Crystals
NASA Technical Reports Server (NTRS)
Burger, A.; Ndap, J.-O.; Chattopadhyay, K.; Ma, X.; Silberman, E.; Feth, S.; Palosz, W.; Su, C.-H.
1999-01-01
At temperatures above 1/2 T(sub m), the generation and movement of dislocations may result due to the load created by the weight of the crystal itself The deformation may be expected to increase the line defect density and may result in generation of low angle grain boundaries, especially in the regions of the crystal attached to the ampule. It has often been suspected that elimination of this effect in space can improve crystallinity of crystals grown under microgravity conditions, however, a direct experimental proof of such relation is still missing. In this work we have designed and built a system of in-situ optical detection and measurement of the mechanical deformations of a crystal wafer under its own weight, and studied the deformation effects as a function of temperature. The results of the measurements for ZnSe and ZnTe crystal wafers will be presented.
The Pressure induced by salt crystallization in confinement.
Desarnaud, J; Bonn, D; Shahidzadeh, N
2016-08-05
Salt crystallization is a major cause of weathering of rocks, artworks and monuments. Damage can only occur if crystals continue to grow in confinement, i.e. within the pore space of these materials, thus generating mechanical stress. We report the direct measurement, at the microscale, of the force exerted by growing alkali halide salt crystals while visualizing their spontaneous nucleation and growth. The experiments reveal the crucial role of the wetting films between the growing crystal and the confining walls for the development of the pressure. Our results suggest that the measured force originates from repulsion between the similarly charged confining wall and the salt crystal separated by a ~1.5 nm liquid film. Indeed, if the walls are made hydrophobic, no film is observed and no repulsive forces are detected. We also show that the magnitude of the induced pressure is system specific explaining why different salts lead to different amounts of damage to porous materials.
Advanced optical technologies for space exploration
NASA Astrophysics Data System (ADS)
Clark, Natalie
2007-09-01
NASA Langley Research Center is involved in the development of photonic devices and systems for space exploration missions. Photonic technologies of particular interest are those that can be utilized for in-space communication, remote sensing, guidance navigation and control, lunar descent and landing, and rendezvous and docking. NASA Langley has recently established a class-100 clean-room which serves as a Photonics Fabrication Facility for development of prototype optoelectronic devices for aerospace applications. In this paper we discuss our design, fabrication, and testing of novel active pixels, deformable mirrors, and liquid crystal spatial light modulators. Successful implementation of these intelligent optical devices and systems in space, requires careful consideration of temperature and space radiation effects in inorganic and electronic materials. Applications including high bandwidth inertial reference units, lightweight, high precision star trackers for guidance, navigation, and control, deformable mirrors, wavefront sensing, and beam steering technologies are discussed. In addition, experimental results are presented which characterize their performance in space exploration systems
Advanced Optical Technologies for Space Exploration
NASA Technical Reports Server (NTRS)
Clark, Natalie
2007-01-01
NASA Langley Research Center is involved in the development of photonic devices and systems for space exploration missions. Photonic technologies of particular interest are those that can be utilized for in-space communication, remote sensing, guidance navigation and control, lunar descent and landing, and rendezvous and docking. NASA Langley has recently established a class-100 clean-room which serves as a Photonics Fabrication Facility for development of prototype optoelectronic devices for aerospace applications. In this paper we discuss our design, fabrication, and testing of novel active pixels, deformable mirrors, and liquid crystal spatial light modulators. Successful implementation of these intelligent optical devices and systems in space, requires careful consideration of temperature and space radiation effects in inorganic and electronic materials. Applications including high bandwidth inertial reference units, lightweight, high precision star trackers for guidance, navigation, and control, deformable mirrors, wavefront sensing, and beam steering technologies are discussed. In addition, experimental results are presented which characterize their performance in space exploration systems.
Trastoy, Beatriz; Lomino, Joseph V; Wang, Lai Xi; Sundberg, Eric J
2013-12-01
Endoglycosidase S (EndoS) is an enzyme secreted by Streptococcus pyogenes that specifically hydrolyzes the β-1,4-di-N-acetylchitobiose core glycan on immunoglobulin G (IgG) antibodies. One of the most common human pathogens and the cause of group A streptococcal infections, S. pyogenes secretes EndoS in order to evade the host immune system by rendering IgG effector mechanisms dysfunctional. On account of its specificity for IgG, EndoS has also been used extensively for chemoenzymatic synthesis of homogeneous IgG glycoprotein preparations and is being developed as a novel therapeutic for a wide range of autoimmune diseases. The structural basis of its enzymatic activity and substrate specificity, however, remains unknown. Here, the purification and crystallization of EndoS are reported. Using traditional hanging-drop and sitting-drop vapor-diffusion crystallization, crystals of EndoS were grown that diffracted to a maximum of 3.5 Å resolution but suffered from severe anisotropy, the data from which could only be reasonably processed to 7.5 Å resolution. When EndoS was crystallized by liquid-liquid diffusion, it was possible to grow crystals with a different space group to those obtained by vapor diffusion. Crystals of wild-type endoglycosidase and glycosynthase constructs of EndoS grown by liquid-liquid diffusion diffracted to 2.6 and 1.9 Å resolution, respectively, with a greatly diminished anisotropy. Despite extensive efforts, the failure to reproduce these liquid-liquid diffusion-grown crystals by vapor diffusion suggests that these crystallization methods each sample a distinct crystallization space.
Processing materials in space - The history and the future
NASA Technical Reports Server (NTRS)
Chassay, Roger; Carswell, Bill
1987-01-01
The development of materials processing in space, and some of the Soyuz, Apollo, Skylab, and Shuttle orbital materials experiments are reviewed. Consideration is given to protein crystal growth, electrophoresis, low-gravity isoelectric focusing, phase partitioning, a monodisperse latex reactor, semiconductor crystal growth, solution crystal growth, the triglycine sulfate experiment, vapor crystal growth experiments, the mercuric iodide experiment, electronic and electrooptical materials, organic thin films and crystalline solids, deep undercooling of metals and alloys, magnetic materials, immiscible materials, metal solidification research, reluctant glass-forming materials, and containerless glass formation. The space processing apparatuses and ground facilities, for materials processing are described. Future facilities for commercial research, development, and manufacturing in space are proposed.
1975-05-06
YAG system, to. be able to operate’in a ground launched satellite. ) Study was conducted to identify and eliminate all sources of laser degradation...further studies and the design of the space-hardened Laser Transmitter.I The study included such topics as general interferometer stability, internally...generated perturbances, external perturbations and their effects on the I’ laser stability. Further study covered the Laser Crystal parameters such as
Space Grown Insulin Crystals Provide New Data on Diabetes
NASA Technical Reports Server (NTRS)
1998-01-01
Diabetic patients may someday reduce their insulin injections and lead more normal lives because of new insights gained through innovative space research in which insulin crystals were grown on the Space Shuttle. Results from a 1994 insulin crystals growth experiment in space are leading to a new understanding of protein insulin. Lack of insulin is the cause of diabetes, a disease that accounts for one-seventh of the nation's health care costs. Champion Deivanaygam, a researcher at the Center for Macromolecular Crystallography at the University of Alabama in Birmingham, assists in this work. Photo credit: NASA/Marshall Space Flight Center (MSFC)
Study of ceramic products and processing techniques in space. [using computerized simulation
NASA Technical Reports Server (NTRS)
Markworth, A. J.; Oldfield, W.
1974-01-01
An analysis of the solidification kinetics of beta alumina in a zero-gravity environment was carried out, using computer-simulation techniques, in order to assess the feasibility of producing high-quality single crystals of this material in space. The two coupled transport processes included were movement of the solid-liquid interface and diffusion of sodium atoms in the melt. Results of the simulation indicate that appreciable crystal-growth rates can be attained in space. Considerations were also made of the advantages offered by high-quality single crystals of beta alumina for use as a solid electrolyte; these clearly indicate that space-grown materials are superior in many respects to analogous terrestrially-grown crystals. Likewise, economic considerations, based on the rapidly expanding technological applications for beta alumina and related fast ionic conductors, reveal that the many superior qualities of space-grown material justify the added expense and experimental detail associated with space processing.
Anderson localization and Mott insulator phase in the time domain
Sacha, Krzysztof
2015-01-01
Particles in space periodic potentials constitute standard models for investigation of crystalline phenomena in solid state physics. Time periodicity of periodically driven systems is a close analogue of space periodicity of solid state crystals. There is an intriguing question if solid state phenomena can be observed in the time domain. Here we show that wave-packets localized on resonant classical trajectories of periodically driven systems are ideal elements to realize Anderson localization or Mott insulator phase in the time domain. Uniform superpositions of the wave-packets form stationary states of a periodically driven particle. However, an additional perturbation that fluctuates in time results in disorder in time and Anderson localization effects emerge. Switching to many-particle systems we observe that depending on how strong particle interactions are, stationary states can be Bose-Einstein condensates or single Fock states where definite numbers of particles occupy the periodically evolving wave-packets. Our study shows that non-trivial crystal-like phenomena can be observed in the time domain. PMID:26074169
Ichida, Takao; Hosogai, Minoru; Yokoyama, Kouji; Ogawa, Takayoshi; Okusako, Kenji; Shougaki, Masachika; Masai, Hironao; Yamada, Eiji; Okuyama, Kazuo; Hatagawa, Masakatsu
2004-09-01
For physicians who monitor images during interventional radiology (VR), we have built and been using a system that employs a liquid crystal display (LCD) instead of the conventional cathode ray tube (CRT). The system incorporates a ceiling-suspension-type monitor (three-display monitor) with an LCD on each of the three displays for the head and abdominal regions and another ceiling-suspension-type monitor (5-display monitor) with an LCD on each display for the cardiac region. As these monitors are made to be thin and light in weight, they can be placed in a high position in the room, thereby saving space and allowing for more effective use of space in the X-ray room. The system has also improved the efficiency of operators in the IVR room. The three-display folding mechanism allows the displays to be viewed from multiple directions, thereby improving the environment so that the performance of IVR can be observed.
Modeling of PCG fluid dynamics: Salient results
NASA Technical Reports Server (NTRS)
Ramachandran, N.
1993-01-01
Materials processing in space-based laboratories has already yielded higher quality crystals during previous space flights, and opportunities for several fluids experiments are anticipated during the extended duration missions planned for the future. Crystal growth in space benefits not only from its reduced gravity environment but also from the absence of the hydrostatic pressure which assists certain crystal growth and refinement methods. Gravity-driven phenomena are thus reduced in strength, and a purely diffusive fluid's behavior can be attained. In addition, past materials science experiments have shown that microgravity can also help produce larger crystals. While gravity-related effects are definitely curtailed in space, they are nevertheless present to some degree due to the acceleration environment onboard the spacecraft. This residual acceleration level is comprised of quasi-steady, oscillatory, and transient components, and is caused by a variety of mechanisms. For example, gravity gradient forces produce low frequency disturbances, and the operation of machinery, control thrusters, solar panels, human activity, etc. contribute to higher frequency accelerations. These disturbances are collectively referred to as g-jitter, and they can be deleterious to certain experiments where the minimization of the acceleration level is important. Advanced vibration isolation techniques can be utilized to actively filter out some of the detrimental frequencies and help in obtaining optimum results. However, the successful application of this technology requires the detailed analysis of candidate fluids experiments to gauge their response to g-jitter and to determine their acceleration sensitivities. Several crystal growth experiments in the Protein Crystal Growth (PCG) area, besides others, are expected to be carried out on future shuttle flights and on Space Station Freedom. The need for vibration isolation systems or components for microgravity science experiments can be expected to grow as experiments and available hardware becomes more complex. This technology will also find increased application as the science community develops an awareness of their specific needs relative to the environment available in manned space missions. Vibration isolation research strives to develop a microgravity environment requirement that defines tolerance limits on the allowable g-level, and provides the required technology to achieve it. This effort will assist in establishing the tolerable acceleration levels for specific fluids experiments. The primary effort is directed towards modeling PCG and the approach undertaken for this investigation is outlined. The objectives of this research are: (1) to computationally determine vibration sensitivity of protein crystal growth experiments; (2) determine if these experiments can benefit from vibration isolation techniques; and (3) provide realistic requirements for vibration isolation technology.
NASA Astrophysics Data System (ADS)
Salian, Vinutha V.; Narayana, Badiadka; Sarojini, Balladka K.; Kumar, Madan S.; Nagananda, Govinahalli S.; Byrappa, Kullaiah; Kudva, Avinash K.
2017-03-01
In the present study, the spectroscopic characterization of a new series of substituted thiazole linked pyrazoline scaffolds 4a-l was performed. The formation of 4a-l from the intermediate 3-(4-chlorophenyl)-5-[4-(propan-2-yl)phenyl]-4,5-dihydro-1H-pyrazole-1-carbothioamide 2 and substituted 2-bromo-1-phenylethanone 3a-l was evidenced through the changes in FTIR, 1H NMR, 13C NMR, LCMS data. The X-ray diffraction studies revealed that compound 2 and 4g crystallized in monoclinic crystal system with P21/n space group. Compound 4j crystallized in triclinic system, P1¯ space group with Z = 4. The percentage of intermolecular contacts and distribution of electrostatic potential of molecular crystal structures was resolved by Hirshfeld surface analysis with 2D finger plots and electrostatic potential map. The newly synthesized derivatives were screened for their in vitro antioxidant and antimicrobial activity. The single crystal studies revealed that, for compounds 2, 4g and 4j the isopropyl phenyl ring is positioned at near right angle with the other rings. Due to the lack of planarity of bulkier group substituted to phenyl ring (ring B), all the synthesized molecules showed weak to moderate radical scavenging capacity owing to the destabilization of the radical formed during oxidation. Also, on performing molecular docking studies to explore the interactions of ligand with the target pyrimidine nucleoside hydrolase YbeK with bound ribose complex (PNH, PDB ID-3GHW), disclosed that active compounds emerged for in vitro studies also bound to PNH more efficiently. The compounds with polar group substitution interacted through hydrogen bonding while other molecules with non-covalent interactions.
A Compact X-Ray System for Support of High Throughput Crystallography
NASA Technical Reports Server (NTRS)
Ciszak, Ewa; Gubarev, Mikhail; Gibson, Walter M.; Joy, Marshall K.; Whitaker, Ann F. (Technical Monitor)
2001-01-01
Standard x-ray systems for crystallography rely on massive generators coupled with optics that guide X-ray beams onto the crystal sample. Optics for single-crystal diffractometry include total reflection mirrors, polycapillary optics or graded multilayer monochromators. The benefit of using polycapillary optic is that it can collect x-rays over tile greatest solid angle, and thus most efficiently, utilize the greatest portion of X-rays emitted from the Source, The x-ray generator has to have a small anode spot, and thus its size and power requirements can be substantially reduced We present the design and results from the first high flux x-ray system for crystallography that combine's a microfocus X-ray generator (40microns FWHM Spot size at a power of 45 W) and a collimating, polycapillary optic. Diffraction data collected from small test crystals with cell dimensions up to 160A (lysozyme and thaumatin) are of high quality. For example, diffraction data collected from a lysozyme crystal at RT yielded R=5.0% for data extending to 1.70A. We compare these results with measurements taken from standard crystallographic systems. Our current microfocus X-ray diffraction system is attractive for supporting crystal growth research in the standard crystallography laboratory as well as in remote, automated crystal growth laboratory. Its small volume, light-weight, and low power requirements are sufficient to have it installed in unique environments, i.e.. on-board International Space Station.
Fluid Flow and Solidification Under Combined Action of Magnetic Fields and Microgravity
NASA Technical Reports Server (NTRS)
Li, B. Q.; Shu, Y.; Li, K.; deGroh, H. C.
2002-01-01
Mathematical models, both 2-D and 3-D, are developed to represent g-jitter induced fluid flows and their effects on solidification under combined action of magnetic fields and microgravity. The numerical model development is based on the finite element solution of governing equations describing the transient g-jitter driven fluid flows, heat transfer and solutal transport during crystal growth with and without an applied magnetic field in space vehicles. To validate the model predictions, a ground-based g-jitter simulator is developed using the oscillating wall temperatures where timely oscillating fluid flows are measured using a laser PIV system. The measurements are compared well with numerical results obtained from the numerical models. Results show that a combined action derived from magnetic damping and microgravity can be an effective means to control the melt flow and solutal transport in space single crystal growth systems.
1992-01-28
The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Vapor Crystal Growth System (VCGS) team in SL POCC), during STS-42, IML-1 mission.
Protein Crystal Quality Studies
NASA Technical Reports Server (NTRS)
1998-01-01
Eddie Snell, Post-Doctoral Fellow the National Research Council (NRC) uses a reciprocal space mapping diffractometer for macromolecular crystal quality studies. The diffractometer is used in mapping the structure of macromolecules such as proteins to determine their structure and thus understand how they function with other proteins in the body. This is one of several analytical tools used on proteins crystallized on Earth and in space experiments. Photo credit: NASA/Marshall Space Flight Center (MSFC)
Biomineral nanoparticles are space-filling.
Yang, Li; Killian, Christopher E; Kunz, Martin; Tamura, Nobumichi; Gilbert, P U P A
2011-02-01
Sea urchin biominerals have been shown to form from aggregating nanoparticles of amorphous calcium carbonate (ACC), which then crystallize into macroscopic single crystals of calcite. Here we measure the surface areas of these biominerals and find them to be comparable to those of space-filling macroscopic geologic calcite crystals. These biominerals differ from synthetic mesocrystals, which are invariably porous. We propose that space-filling ACC is the structural precursor for echinoderm biominerals.
Large scale crystallization of protein pharmaceuticals in microgravity via temperature change
NASA Technical Reports Server (NTRS)
Long, Marianna M.
1992-01-01
The major objective of this research effort is the temperature driven growth of protein crystals in large batches in the microgravity environment of space. Pharmaceutical houses are developing protein products for patient care, for example, human insulin, human growth hormone, interferons, and tissue plasminogen activator or TPA, the clot buster for heart attack victims. Except for insulin, these are very high value products; they are extremely potent in small quantities and have a great value per gram of material. It is feasible that microgravity crystallization can be a cost recoverable, economically sound final processing step in their manufacture. Large scale protein crystal growth in microgravity has significant advantages from the basic science and the applied science standpoints. Crystal growth can proceed unhindered due to lack of surface effects. Dynamic control is possible and relatively easy. The method has the potential to yield large quantities of pure crystalline product. Crystallization is a time honored procedure for purifying organic materials and microgravity crystallization could be the final step to remove trace impurities from high value protein pharmaceuticals. In addition, microgravity grown crystals could be the final formulation for those medicines that need to be administered in a timed release fashion. Long lasting insulin, insulin lente, is such a product. Also crystalline protein pharmaceuticals are more stable for long-term storage. Temperature, as the initiation step, has certain advantages. Again, dynamic control of the crystallization process is possible and easy. A temperature step is non-invasive and is the most subtle way to control protein solubility and therefore crystallization. Seeding is not necessary. Changes in protein and precipitant concentrations and pH are not necessary. Finally, this method represents a new way to crystallize proteins in space that takes advantage of the unique microgravity environment. The results from two flights showed that the hardware performed perfectly, many crystals were produced, and they were much larger than their ground grown controls. Morphometric analysis was done on over 4,000 crystals to establish crystal size, size distribution, and relative size. Space grown crystals were remarkably larger than their earth grown counterparts and crystal size was a function of PCF volume. That size distribution for the space grown crystals was a function of PCF volume may indicate that ultimate size was a function of temperature gradient. Since the insulin protein concentration was very low, 0.4 mg/ml, the size distribution could also be following the total amount of protein in each of the PCF's. X-ray analysis showed that the bigger space grown insulin crystals diffracted to higher resolution than their ground grown controls. When the data were normalized for size, they still indicated that the space crystals were better than the ground crystals.
NASA Astrophysics Data System (ADS)
Sudhakar, K.; Nandhini, S.; Muniyappan, S.; Arumanayagam, T.; Vivek, P.; Murugakoothan, P.
2018-04-01
Ammonium sulfate hydrogen sulphamate (ASHS), an inorganic nonlinear optical crystal, was grown from the aqueous solution by slow evaporation solution growth technique. The single-crystal XRD confirms that the grown single crystal belongs to the orthorhombic system with the space group of Pna21. Powder XRD confirms the crystalline nature and the diffraction planes were indexed. Crystalline perfection of grown crystal was analysed by high-resolution X-ray diffraction rocking curve technique. UV-Vis-NIR studies revealed that ASHS crystal has optical transparency 65% and lower cut-off wavelength at 218 nm. The violet light emission of the crystal was identified by photoluminescence studies. The particle size-dependent second-harmonic generation efficiency for ASHS crystal was evaluated by Kurtz-Perry powder technique using Nd:YAG laser which established the existence of phase matching. Surface laser damage threshold value was evaluated using Nd:YAG laser. Optical homogeneity of the crystal was evaluated using modified channel spectrum method through birefringence study. Thermal analysis reveals that ASHS crystal is stable up to 213 °C. The mechanical behaviour of the ASHS crystal was analysed using Vickers microhardness study.
Black, Cameron; Lightfoot, Philip
2017-03-01
Vanadium fluorides with novel crystal-chemical features and interesting physical properties can be prepared by solvothermal synthetic routes. The title compound, guanidinium hexafluoridovanadate(III), has a cubic structure (space group Pa-3), exhibiting isolated regular VF 6 octahedral units, which are hydrogen bonded to protonated guanidinium moieties. Although the VF 6 octahedral units are not linked directly together, there are structural similarities between this crystal structure and those of the wider family of perovskite materials, in particular, hybrid perovskites based on extended ligands such as cyanide. In this context, the octahedral tilt system of the present compound is of interest and demonstrates that unusual tilt systems can be mediated via `molecular' linkers which allow only supramolecular rather than covalent interactions.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peng, Ying; Xu, Feng, E-mail: xuf@xtal.tsinghua.edu.cn; Bell, Stephen G.
Palustrisredoxin reductase (RPA3782, PuR), a flavin-dependent ferredoxin reductase, is an essential component of the Class I cytochrome P450 systems in Rhodopseudomonas palustris CGA009. Crystals of PuR that diffract to 2.2 Å resolution have been obtained. Palustrisredoxin reductase from Rhodopseudomonas palustris CGA009, a member of the oxygenase-coupled NADH-dependent ferredoxin reductase (ONFR) family, catalyzes electron transfer from NADH to ferredoxins. It is an essential component of the cytochrome P450 systems in R. palustris CGA009, a model organism with diverse metabolic pathways. Here, the crystallization of palustrisredoxin reductase is reported. The crystals belong to the trigonal space group P3{sub 2}21, with unit-cell parametersmore » a = 107.5, b = 107.5, c = 69.9 Å, and diffract to 2.2 Å resolution on a synchrotron source.« less
NASA Astrophysics Data System (ADS)
Yonemoto, Koichi; Yamamoto, Yuta; Okuyama, Keiichi; Ebina, Takeo
In the future, carbon fiber reinforced plastics (CFRPs) with high hydrogen gas barrier performance will find wide applications in all industrial hydrogen tanks that aim at weight reduction; the use of such materials will be preferred to the use of conventional metallic materials such as stainless steel or aluminum. The hydrogen gas barrier performance of CFRP will become an important issue with the introduction of hydrogen-fuel aircraft. It will also play an important role in realizing fully reusable space transportation system that will have high specific tensile CFRP structures. Such materials are also required for the manufacture of high-pressure hydrogen gas vessels for use in the fuel cell systems of automobiles. This paper introduces a new composite concept that can be used to realize CFRPs with high hydrogen gas barrier performance for applications in the cryogenic tanks of fully reusable space transportation system by the incorporation of a nonmetallic crystal layer, which is actually a dense and highly oriented clay crystal laminate. The preliminary test results show that the hydrogen gas barrier characteristics of this material after cryogenic heat shocks and cyclic loads are still better than those of other polymer materials by approximately two orders of magnitude.
Crystallization of chicken egg white lysozyme from assorted sulfate salts
NASA Astrophysics Data System (ADS)
Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.
1999-01-01
Chicken egg white lysozyme has been found to crystallize from ammonium, sodium, potassium, rubidium, magnesium, and manganese sulfates at acidic and basic pH, with protein concentrations from 60 to 190 mg/ml. Crystals have also been grown at 4°C in the absence of any other added salts using isoionic lysozyme which was titrated to pH 4.6 with dilute sulfuric acid. Four different crystal forms have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed. Crystals grown at 15°C were generally tetragonal, with space group P4 32 12. Crystallization at 20°C typically resulted in the formation of orthorhombic crystals, space group P2 12 12 1. The tetragonal ↔ orthorhombic transition appeared to be a function of both the temperature and protein concentration, occurring between 15 and 20°C and between 100 and 125 mg/ml protein concentration. Crystallization from 1.2 M magnesium sulfate at pH 7.8 gave a trigonal crystal, space group P3 12 1, a= b=87.4, c=73.7, γ=120°, which diffracted to 2.8 Å. Crystallization from ammonium sulfate at pH 4.6, generally at lower temperatures, was also found to result in a monoclinic form, space group C2, a=65.6, b=95.0, c=41.2, β=119.2°. A crystal of ˜0.2×0.2×0.5 mm grown from bulk solution diffracted to ˜3.5 Å.
Topological Valley Transport in Two-dimensional Honeycomb Photonic Crystals.
Yang, Yuting; Jiang, Hua; Hang, Zhi Hong
2018-01-25
Two-dimensional photonic crystals, in analogy to AB/BA stacking bilayer graphene in electronic system, are studied. Inequivalent valleys in the momentum space for photons can be manipulated by simply engineering diameters of cylinders in a honeycomb lattice. The inequivalent valleys in photonic crystal are selectively excited by a designed optical chiral source and bulk valley polarizations are visualized. Unidirectional valley interface states are proved to exist on a domain wall connecting two photonic crystals with different valley Chern numbers. With the similar optical vortex index, interface states can couple with bulk valley polarizations and thus valley filter and valley coupler can be designed. Our simple dielectric PC scheme can help to exploit the valley degree of freedom for future optical devices.
Two-Dimensional Photonic Crystals for Sensitive Microscale Chemical and Biochemical Sensing
Miller, Benjamin L.
2015-01-01
Photonic crystals – optical devices able to respond to changes in the refractive index of a small volume of space – are an emerging class of label-free chemical-and bio-sensors. This review focuses on one class of photonic crystal, in which light is confined to a patterned planar material layer of sub-wavelength thickness. These devices are small (on the order of tens to 100s of microns square), suitable for incorporation into lab-on-a-chip systems, and in theory can provide exceptional sensitivity. We introduce the defining characteristics and basic operation of two-dimensional photonic crystal sensors, describe variations of their basic design geometry, and summarize reported detection results from chemical and biological sensing experiments. PMID:25563402
Protein crystal growth results from the United States Microgravity Laboratory-1 mission
NASA Technical Reports Server (NTRS)
Delucas, Lawrence J.; Moore, K. M.; Vanderwoerd, M.; Bray, T. L.; Smith, C.; Carson, M.; Narayana, S. V. L.; Rosenblum, W. M.; Carter, D.; Clark, A. D, Jr.
1994-01-01
Protein crystal growth experiments have been performed by this laboratory on 18 Space Shuttle missions since April, 1985. In addition, a number of microgravity experiments also have been performed and reported by other investigators. These Space Shuttle missions have been used to grow crystals of a variety of proteins using vapor diffusion, liquid diffusion, and temperature-induced crystallization techniques. The United States Microgravity Laboratory - 1 mission (USML-1, June 25 - July 9, 1992) was a Spacelab mission dedicated to experiments involved in materials processing. New protein crystal growth hardware was developed to allow in orbit examination of initial crystal growth results, the knowledge from which was used on subsequent days to prepare new crystal growth experiments. In addition, new seeding hardware and techniques were tested as well as techniques that would prepare crystals for analysis by x-ray diffraction, a capability projected for the planned Space Station. Hardware that was specifically developed for the USML-1 mission will be discussed along with the experimental results from this mission.
NASA Astrophysics Data System (ADS)
Bharti, Sulakshna; Choudhary, Mukesh; Mohan, Bharti; Rawat, S. P.; Sharma, S. R.; Ahmad, Khursheed
2017-12-01
Three new copper (II) and nickel (II) complexes viz. [Cu(L)2](1a), [Cu(L)2](1b) and [Ni(L)2].DMF(2), where HL = 2-((E)-(2, 4-dibromophenylimino) methyl)-4-bromophenol, have been synthesized and characterized by using various physico-chemical and spectroscopic techniques. The crystal structures of Schiff base (HL) and their metal complexes (1a), (1b) and (2) were determined by single crystal X-ray diffraction. IR and UV-Vis spectra and magnetic susceptibility measurements agree with the observed crystal structures. The crystallographic and spectroscopic studies confirmed four coordinate environments around the metal (II) ions. The synthesized Schiff base ligand (HL) crystallizes in the orthorhombic system of the space group Pbca. Complex (1a) of HL was crystallized in the monoclinic system of the space group P21/c, a = 10.1712(9) Å, b = 10.9299(10) Å,c = 12.7684(11) Å,α = 90̊,β = 104.649(2)̊, γ = 90̊ and Z = 2 whereas complex (1b) and (2) crystallized in the triclinic system of the space group P-1, a = 11.499(5)Å, b = 11.598(5)Å, c = 12.211(5)Å, α = 98.860(5), β = 115.653(5),γ = 100.906(5) and Z = 2 for (1b), a = 9.080(6) Å, b = 9.545(8)Å, c = 9.545(8)Å, α = 101.43(4)º,β = 99.63(3)̊, γ = 117.71(2)º and Z = 1 for (2). The synthesized ligand (HL) was behaved as monobasic bidentate Schiff base ligand having N and O donor sites. The electron paramagnetic resonance spectra indicate a dx2-y2ground state (g|| > g⊥> 2.0023) for (1a) and (1b). Copper (II) complexes display X-band EPR spectra in 100% DMSO and 77 K, giving indicating dx2-y2ground state. Superoxide dismutase-like activities of HL and its complexes were investigated by nitrobluetetrazolium chloride-DMSO assay and IC50 values were evaluated. These complexes were also tested for their in vitro antimicrobial activities against two bacteria (E. coli and Salmonella typhi) and two fungi (Pencillium, Aspergillus sp.) comparing with the Schiff base. The antimicrobial results showed that the complexes were more biologically active compounds to the Schiff base (HL).
NASA Astrophysics Data System (ADS)
Sugahara, Mitsuaki; Sekino-Suzuki, Naoko; Ohno-Iwashita, Yoshiko; Miki, Kunio
1996-10-01
θ-Toxin (perfringolysin O), a cholesterol-binding, pore-forming cytolysin of Clostridium perfringens type A was crystallized by the vapor diffusion procedure using polyethyleneglycol 4000 and sodium chloride as precipitants in 2-(cyclohexylamino)ethanesulfonic acid (CHES) buffer at pH 9.5. The diffraction patterns of precession photographs indicated that the crystals belong to the orthorhombic system and the space group C222 1 with unit-cell dimensions of a = 47.7 Å, b = 182.0 Å and c = 175.8 Å. Assuming that the asymmetric unit contains one or two molecules (Mw 52 700), the Vm value is calculated as 3.6 or 1.8 Å 3/dalton, respectively. The crystals diffract X-rays to at least 3 Å resolution and are suitable for high resolution X-ray crystal structure determination.
Liquid nitrogen dewar for protein crystal growth
NASA Technical Reports Server (NTRS)
2001-01-01
Gaseous Nitrogen Dewar apparatus developed by Dr. Alex McPherson of the University of California, Irvine for use aboard Mir and the International Space Station allows large quantities of protein samples to be crystallized in orbit. The specimens are contained either in plastic tubing (heat-sealed at each end). Biological samples are prepared with a precipitating agent in either a batch or liquid-liquid diffusion configuration. The samples are then flash-frozen in liquid nitrogen before crystallization can start. On orbit, the Dewar is placed in a quiet area of the station and the nitrogen slowly boils off (it is taken up by the environmental control system), allowing the proteins to thaw to begin crystallization. The Dewar is returned to Earth after one to four months on orbit, depending on Shuttle flight opportunities. The tubes then are analyzed for crystal presence and quality
Crystal growth of device quality GaAs in space
NASA Technical Reports Server (NTRS)
Gatos, H. C.; Lagowski, J.
1983-01-01
GaAs device technology has recently reached a new phase of rapid advancement, made possible by the improvement of the quality of GaAs bulk crystals. At the same time, the transition to the next generation of GaAs integrated circuits and optoelectronic systems for commercial and government applications hinges on new quantum steps in three interrelated areas: crystal growth, device processing and device-related properties and phenomena. Special emphasis is placed on the establishment of quantitative relationships among crystal growth parameters-material properties-electronic properties and device applications. The overall program combines studies of crystal growth on novel approaches to engineering of semiconductor material (i.e., GaAs and related compounds); investigation and correlation of materials properties and electronic characteristics on a macro- and microscale; and investigation of electronic properties and phenomena controlling device applications and device performance.
Structural study of quasi-one-dimensional vanadium pyroxene LiVSi{sub 2}O{sub 6} single crystals
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ishii, Yuto; Matsushita, Yoshitaka; Oda, Migaku
Single crystals of quasi-one-dimensional vanadium pyroxene LiVSi{sub 2}O{sub 6} were synthesized and the crystal structures at 293 K and 113 K were studied using X-ray diffraction experiments. We found a structural phase transition from the room-temperature crystal structure with space group C2/c to a low-temperature structure with space group P2{sub 1}/c, resulting from a rotational displacement of SiO{sub 4} tetrahedra. The temperature dependence of magnetic susceptibility shows a broad maximum around 116 K, suggesting an opening of the Haldane gap expected for one-dimensional antiferromagnets with S=1. However, an antiferromagnetic long-range order was developed below 24 K, probably caused by amore » weak inter-chain magnetic coupling in the compound. - Graphical abstract: Low temperature crystal structure of LiVSi{sub 2}O{sub 6} and an orbital arrangement within the V-O zig-zag chain along the c-axis. - Highlights: • A low temperature structure of LiVSi{sub 2}O{sub 6} was determined by single crystal X-ray diffraction measurements. • The origin of the structural transition is a rotational displacement of SiO{sub 4} tetrahedra. • The uniform orbital overlap in the V-O zigzag chain makes the system a quasi one-dimensional antiferromagnet.« less
NASA Astrophysics Data System (ADS)
Karthigha, S.; Krishnamoorthi, C.
2018-03-01
An organic quinolinium derivative nonlinear optical (NLO) crystal, 1-ethyl-2-[2-(4-nitro-phenyl)-vinyl]-quinolinium iodide (PNQI) was synthesized and successfully grown by slow evaporation solution growth technique. Formation of a crystalline compound was confirmed by single crystal X-ray diffraction. The quinolinium compound PNQI crystallizes in the triclinic crystal system with a centrosymmetric space group of P-1 symmetry. The molecular structure of PNQI was confirmed by 1H NMR and 13C NMR spectral studies. The thermal properties of the crystal have been investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC) studies. The optical characteristics obtained from UV-Vis-NIR spectral data were described and the cut-off wavelength observed at 506 nm. The etching study was performed to analyse the growth features of PNQI single crystal. The third order NLO properties such as nonlinear refractive index (n2), nonlinear absorption coefficient (β) and nonlinear susceptibility (χ (3)) of the crystal were investigated using Z-scan technique at 632.8 nm of Hesbnd Ne laser.
NASA Astrophysics Data System (ADS)
Alexandar, A.; Lakshmanan, A.; Sakthy Priya, S.; Surendran, P.; Rameshkumar, P.
2017-09-01
Nonlinear optical single crystals of L-lysine p-nitrophenolate monohydrate (LLPNP) were grown in aqueous solution by the slow evaporation solution technique (SEST). The grown crystals were subjected to powder X-ray diffraction analysis, (PXRD) and it was found that the title compound was crystallized in the orthorhombic crystal system with noncentrosymmetric space group of P212121. The vibrational frequencies of various functional groups present in the crystal were analyzed using the FTIR spectrum with a wavenumber range between 450 cm-1 and 4000 cm-1. The microhardness analysis of the sample revealed that the crystal belongs to the soft material category. Piezoelectric analysis was performed to measure the value of the piezoelectric (d33) coefficient. Blue light emission of the material was confirmed using the photoluminescence spectrum. Thermal stability of the grown crystal was analyzed using a melting point apparatus and it was found that the LLPNP is stable upto 175∘C. Etching analysis was performed at various durations, in order to identify the surface properties of the LLPNP crystal.
NASA Technical Reports Server (NTRS)
Arakere, Nagaraj K.; Swanson, Gregory R.
2000-01-01
High Cycle Fatigue (HCF) induced failures in aircraft gas-turbine engines is a pervasive problem affecting a wide range of components and materials. HCF is currently the primary cause of component failures in gas turbine aircraft engines. Turbine blades in high performance aircraft and rocket engines are increasingly being made of single crystal nickel superalloys. Single-crystal Nickel-base superalloys were developed to provide superior creep, stress rupture, melt resistance and thermomechanical fatigue capabilities over polycrystalline alloys previously used in the production of turbine blades and vanes. Currently the most widely used single crystal turbine blade superalloys are PWA 1480/1493 and PWA 1484. These alloys play an important role in commercial, military and space propulsion systems. PWA1493, identical to PWA1480, but with tighter chemical constituent control, is used in the NASA SSME (Space Shuttle Main Engine) alternate turbopump, a liquid hydrogen fueled rocket engine. Objectives for this paper are motivated by the need for developing failure criteria and fatigue life evaluation procedures for high temperature single crystal components, using available fatigue data and finite element modeling of turbine blades. Using the FE (finite element) stress analysis results and the fatigue life relations developed, the effect of variation of primary and secondary crystal orientations on life is determined, at critical blade locations. The most advantageous crystal orientation for a given blade design is determined. Results presented demonstrates that control of secondary and primary crystallographic orientation has the potential to optimize blade design by increasing its resistance to fatigue crack growth without adding additional weight or cost.
NASA Astrophysics Data System (ADS)
Bondarenko, Yu. A.; Echin, A. B.; Surova, V. A.; Kolodyazhnyi, M. Yu.
2017-05-01
The effect of the conditions of directed crystallization (the temperature gradient and the crystallization rate) on the dendrite spacing, on the size of the particles of the hardening γ'-phase in the arms and arm spaces of the dendrites, on the volume fraction and size of the pores, on the size of the particles of the eutectic γ/γ'-phase, and on the features of dendritic segregation in a single-crystal castable refractory alloy is studied.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fathima, K. Saiadali; Vasumathi, M.; Anitha, K., E-mail: singlecrystalxrd@gmail.com
2016-05-23
The novel organic material C{sub 20}H{sub 21}ClN{sub 2}O was synthesized by One-Pot synthesis method and the single crystals were grown by slow evaporation solution growth technique. The crystal structure was elucidated by subjecting the grown crystals to the single crystal x-ray diffraction analysis and was refined by full matrix least-squares method to R=0.039 for 2746 reflections. Crystal system of the grown crystal was found to be monoclinic with the space group P2{sub 1}/a and a=9.196(4) Å, b=13.449(4) Å, c=14.818(4) Å, β= 101.542(3)°, V=1795.6(11) Å{sup 3} and Z=4. In this crystal structure, cyclooctanone prefers to reside in a chair-boat conformation. Themore » structure is stabilized by attractive molecular force such as CH/π interaction called hydrophobic interaction.« less
Zeolite crystal growth in space - What has been learned
NASA Technical Reports Server (NTRS)
Sacco, A., Jr.; Thompson, R. W.; Dixon, A. G.
1993-01-01
Three zeolite crystal growth experiments developed at WPI have been performed in space in last twelve months. One experiment, GAS-1, illustrated that to grow large, crystallographically uniform crystals in space, the precursor solutions should be mixed in microgravity. Another experiment evaluated the optimum mixing protocol for solutions that chemically interact ('gel') on contact. These results were utilized in setting the protocol for mixing nineteen zeolite solutions that were then processed and yielded zeolites A, X and mordenite. All solutions in which the nucleation event was influenced produced larger, more 'uniform' crystals than did identical solutions processed on earth.
Efficient modeling of photonic crystals with local Hermite polynomials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boucher, C. R.; Li, Zehao; Albrecht, J. D.
2014-04-21
Developing compact algorithms for accurate electrodynamic calculations with minimal computational cost is an active area of research given the increasing complexity in the design of electromagnetic composite structures such as photonic crystals, metamaterials, optical interconnects, and on-chip routing. We show that electric and magnetic (EM) fields can be calculated using scalar Hermite interpolation polynomials as the numerical basis functions without having to invoke edge-based vector finite elements to suppress spurious solutions or to satisfy boundary conditions. This approach offers several fundamental advantages as evidenced through band structure solutions for periodic systems and through waveguide analysis. Compared with reciprocal space (planemore » wave expansion) methods for periodic systems, advantages are shown in computational costs, the ability to capture spatial complexity in the dielectric distributions, the demonstration of numerical convergence with scaling, and variational eigenfunctions free of numerical artifacts that arise from mixed-order real space basis sets or the inherent aberrations from transforming reciprocal space solutions of finite expansions. The photonic band structure of a simple crystal is used as a benchmark comparison and the ability to capture the effects of spatially complex dielectric distributions is treated using a complex pattern with highly irregular features that would stress spatial transform limits. This general method is applicable to a broad class of physical systems, e.g., to semiconducting lasers which require simultaneous modeling of transitions in quantum wells or dots together with EM cavity calculations, to modeling plasmonic structures in the presence of EM field emissions, and to on-chip propagation within monolithic integrated circuits.« less
NASA Astrophysics Data System (ADS)
Moriguchi, Tetsuji; Tabuchi, Daichi; Yakeya, Daisuke; Tsuge, Akihiko; Jalli, Venkataprasad; Yoza, Kenji
2018-01-01
Two s-shaped fluorinated isomeric polyaromatic dibenzo[c,l]chrysene derivatives have been synthesized by a two step process using the Wittig, Heck and iodine promoted cyclization reactions. These cyclized compounds were characterized by 1H NMR and EI-MS. Further, absolute configurations of isomeric 4a and 4b were determined by X-ray diffraction analysis. Compound 4a crystallized under monoclinic system with space group P21/c and compound 4b crystallized under monoclinic system with space group Cc. They have good solubility in common organic solvents such as dichloromethane, chloroform and THF. Photophysical properties of 4a and 4b were evaluated by using UV-Visible and Fluorescence spectrophotometer. Compounds 4a and 4b showed strong absorption maximum wavelength at 317 nm. The emission spectra of 4a and 4b displayed sharp peaks in the visible region from 417 to 441 nm. The shape of the UV-Visible and Fluorescence spectra of 4a and 4b looks almost identical. But compound 4a exhibited better fluorescence intensity than compound 4b. This difference may be due to the difference in the configuration of compounds 4a and 4b.
NASA Astrophysics Data System (ADS)
Avery, Patrick; Zurek, Eva
2017-04-01
A new algorithm, RANDSPG, that can be used to generate trial crystal structures with specific space groups and compositions is described. The program has been designed for systems where the atoms are independent of one another, and it is therefore primarily suited towards inorganic systems. The structures that are generated adhere to user-defined constraints such as: the lattice shape and size, stoichiometry, set of space groups to be generated, and factors that influence the minimum interatomic separations. In addition, the user can optionally specify if the most general Wyckoff position is to be occupied or constrain select atoms to specific Wyckoff positions. Extensive testing indicates that the algorithm is efficient and reliable. The library is lightweight, portable, dependency-free and is published under a license recognized by the Open Source Initiative. A web interface for the algorithm is publicly accessible at http://xtalopt.openmolecules.net/randSpg/randSpg.html. RANDSPG has also been interfaced with the XTALOPT evolutionary algorithm for crystal structure prediction, and it is illustrated that the use of symmetric lattices in the first generation of randomly created individuals decreases the number of structures that need to be optimized to find the global energy minimum.
Procedure to prepare transparent silica gels
NASA Technical Reports Server (NTRS)
Barber, Patrick G. (Inventor); Simpson, Norman R. (Inventor)
1987-01-01
This invention relates to the production of silica gels and in particular to a process for the preparation of silica gels which can be used as a crystal growth medium that simulates the convectionless environment of space to produce structurally perfect crystals. Modern utilizations of substances in electronics, such as radio transmitters and high frequency microphones, often require single crystals with controlled purity and structural perfection. The near convectionless environment of silica gel suppresses nucleation, thereby reducing the competitive nature of crystal growth. This competition limits the size and perfection of the crystal; and it is obviously desirable to suppress nucleation until, ideally, only one crystal grows in a predetermined location. A silica gel is not a completely convectionless environment like outer space, but is the closest known environment to that of outer space that can be created on Earth.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Park, Hyun Ho; Tookes, Hansel Emory; Wu, Hao, E-mail: haowu@med.cornell.edu
2006-06-01
The D. melanogaster Drep-3 protein has been crystallized. Crystals were obtained at 293 K that diffracted to 2.8 Å resolution and belonged to space group P2{sub 1}2{sub 1}2{sub 1}. During apoptosis, DNA fragmentation is mainly mediated by the caspase-activated DFF40 nuclease. DFF40 exists as a heterodimeric complex with its inhibitor DFF45. Upon apoptosis induction, DFF45 is cleaved by caspases to allow DFF40 activation. Drep-3 is a recently identified regulator of the DFF40 system in Drosophila melanogaster. Here, Drep-3 was expressed with a C-terminal His tag in Escherichia coli and the protein was purified to homogeneity. Multi-angle light-scattering analysis showed thatmore » Drep-3 is a homotetramer in solution. Native and selenomethionine-substituted Drep-3 proteins were crystallized at 293 K and X-ray diffraction data were collected to 2.8 and 3.0 Å resolution, respectively. The crystals belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 56.9, b = 125.4, c = 168.7 Å. The asymmetric unit is estimated to contain one homotetramer.« less
Rapid crystallization and morphological adjustment of zeolite ZSM-5 in nonionic emulsions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang Ying, E-mail: yingzh1977@163.co; Jin Chao; Research Institute of Petroleum Processing, Beijing 100083
2011-01-15
Zeolite ZSM-5 was synthesized for the first time in a nonionic emulsion composed of polyoxyethylated alkylphenol, butanol, cyclohexane and tetraethylammonium hydroxide (TEAOH)-containing zeolite synthesis mixture. The crystallization kinetics in the emulsion was investigated and the ZSM-5 product was characterized in detail by XRD, SEM, FT-IR, TG, N{sub 2} adsorption and CHN analysis techniques. Compared with the conventionally hydrothermal synthesis with the same structure directing agent TEAOH, the emulsion system allows rapid crystallization of ZSM-5. The ZSM-5 product exhibits unusual agglomerated structure and possesses larger specific surface area. The FT-IR, TG results plus CHN analysis show the encapsulation of a tracemore » of emulsion components in the emulsion ZSM-5. Control experiments show the emulsion system exerts the crystallization induction and morphological adjustment effects mainly during the aging period. The effects are tentatively attributed to the confined space domains, surfactant-water interaction as well as surfactant-growing crystals interaction existing in the emulsion. -- Graphical abstract: The nonionic emulsion synthesis allows rapid crystallization and morphological adjustment of zeolite ZSM-5 compared with the conventional hydrothermal synthesis. Display Omitted« less
Space Grown Insulin Crystals Provide New Data on Diabetes
NASA Technical Reports Server (NTRS)
1998-01-01
Diabetic patients may someday reduce their insulin injections and lead more normal lives because of new insights gained through irnovative space research in which insulin crystals were grown on the Space Shuttle. Results from a 1994 insulin crystal growth experiment in space are leading to a new understanding of protein insulin. Lack of insulin is the cause of diabetes, a desease that accounts for one-seventh of the nation's health care costs. Dr. Marianna Long, associate director of the Center of Macromolecular Crystallography at the University of Alabama at Birmingham, is a co-investigator on the research. Photo credit: NASA/Marshall Space Flight Center (MSFC)
Crystal structure of hydrocortisone acetate, C23H32O6
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kaduk, James A.; Gindhart, Amy M.; Blanton, Thomas N.
The crystal structure of hydrocortisone acetate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Hydrocortisone acetate crystallizes in space groupP2 1(#4) witha= 8.85173(3) Å,b= 13.53859(3) Å,c= 8.86980(4) Å,β= 101.5438(3)°,V= 1041.455(6) Å 3, andZ= 2. Both hydroxyl groups form hydrogen bonds to the ketone oxygen atom on the steroid ring system, resulting in a three-dimensional hydrogen bond network. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.
Statistical foundations of liquid-crystal theory: II: Macroscopic balance laws.
Seguin, Brian; Fried, Eliot
2013-01-01
Working on a state space determined by considering a discrete system of rigid rods, we use nonequilibrium statistical mechanics to derive macroscopic balance laws for liquid crystals. A probability function that satisfies the Liouville equation serves as the starting point for deriving each macroscopic balance. The terms appearing in the derived balances are interpreted as expected values and explicit formulas for these terms are obtained. Among the list of derived balances appear two, the tensor moment of inertia balance and the mesofluctuation balance, that are not standard in previously proposed macroscopic theories for liquid crystals but which have precedents in other theories for structured media.
NASA Technical Reports Server (NTRS)
Casay, G. A.; Wilson, W. W.
1992-01-01
One type of hardware used to grow protein crystals in the microgravity environment aboard the U.S. Space Shuttle is a hanging drop vapor diffusion apparatus (HDVDA). In order to optimize crystal growth conditions, dynamic control of the HDVDA is desirable. A critical component in the dynamically controlled system is a detector for protein nucleation. We have constructed a laser scattering detector for the HDVDA capable of detecting the nucleation stage. The detector was successfully tested for several scatterers differing in size using dynamic light scattering techniques. In addition, the ability to detect protein nucleation using the HDVDA was demonstrated for lysozyme.
Update on the NASA Glenn PSL Ice Crystal Cloud Characterization (2016)
NASA Technical Reports Server (NTRS)
Van Zante, J.; Bencic, T.; Ratvasky, Thomas P.; Struk, Peter M.
2016-01-01
NASA Glenn's Propulsion Systems Laboratory (PSL) is an altitude engine research test facility capable of producing ice-crystal and supercooled liquid clouds. The cloud characterization parameter space is fairly large and complex, but the phase of the cloud seems primarily governed by wet bulb temperature. The presentation will discuss some of the issues uncovered through four cloud characterization efforts to date, as well as some of instrumentation that has been used to characterize cloud parameters including cloud uniformity, bulk total water content, median volumetric diameter and max-diameter, percent freeze-out, relative humidity, and an update on the NASA Glenn PSL Ice Crystal Cloud Characterization (2016).
Statistical foundations of liquid-crystal theory
Seguin, Brian; Fried, Eliot
2013-01-01
Working on a state space determined by considering a discrete system of rigid rods, we use nonequilibrium statistical mechanics to derive macroscopic balance laws for liquid crystals. A probability function that satisfies the Liouville equation serves as the starting point for deriving each macroscopic balance. The terms appearing in the derived balances are interpreted as expected values and explicit formulas for these terms are obtained. Among the list of derived balances appear two, the tensor moment of inertia balance and the mesofluctuation balance, that are not standard in previously proposed macroscopic theories for liquid crystals but which have precedents in other theories for structured media. PMID:23554513
NASA Astrophysics Data System (ADS)
Abosadiya, Hamza M.; Anouar, El Hassane; Abusaadiya, Salima M.; Hasbullah, Siti Aishah; Yamin, Bohari M.
2018-01-01
A simple efficient method for synthesis of some new 1,2,4-Triazole and Triazolidin derivatives namely, 5-(4-methoxyphenyl)-2-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (1a), (2-chlorophenyl)(3,3-dimethyl-1-phenyl-5-thioxo-1,2,4-triazolidin-4-yl)methanone (1b) and (2-iodophenyl)(3,3-dimethyl-1-phenyl-5-thioxo-1,2,4-triazolidin-4-yl)methanone (1c) have been synthesized in high yields from the reaction of carbonoyl isothiocyanate with phenyl hydrazine. The final products were characterized by FT-IR, 1H and 13C NMR spectroscopic techniques. X-ray crystallographic studies showed that 1a crystallized in triclinic crystal system with space group Pī, while both 1b and 1c crystallized in orthorhombic crystal system with space group Pna21. The asymmetric unit of 1a consists two crystallographically independent molecules, while only one molecule in asymmetric unit for both 1b and 1c compounds. All molecules possess Csbnd H ….S intramolecular hydrogen bonds which formed a pseudo-six-membered ring. Experimental results have been confirmed by the state-of-art density functional theory (DFT) in gas and solvent phase by using five different hybrid functionals B3LYP, B3P86, CAM-B3LYP, M06-2X and PBE0 combined with 6-311++G(d, p) basis set. The experimental data are relatively well produced, and relatively good correlations are obtained between the predicted and experimental data.
Phase diagram of a symmetric electron–hole bilayer system: a variational Monte Carlo study
NASA Astrophysics Data System (ADS)
Sharma, Rajesh O.; Saini, L. K.; Prasad Bahuguna, Bhagwati
2018-05-01
We study the phase diagram of a symmetric electron–hole bilayer system at absolute zero temperature and in zero magnetic field within the quantum Monte Carlo approach. In particular, we conduct variational Monte Carlo simulations for various phases, i.e. the paramagnetic fluid phase, the ferromagnetic fluid phase, the anti-ferromagnetic Wigner crystal phase, the ferromagnetic Wigner crystal phase and the excitonic phase, to estimate the ground-state energy at different values of in-layer density and inter-layer spacing. Slater–Jastrow style trial wave functions, with single-particle orbitals appropriate for different phases, are used to construct the phase diagram in the (r s , d) plane by finding the relative stability of trial wave functions. At very small layer separations, we find that the fluid phases are stable, with the paramagnetic fluid phase being particularly stable at and the ferromagnetic fluid phase being particularly stable at . As the layer spacing increases, we first find that there is a phase transition from the ferromagnetic fluid phase to the ferromagnetic Wigner crystal phase when d reaches 0.4 a.u. at r s = 20, and before there is a return to the ferromagnetic fluid phase when d approaches 1 a.u. However, for r s < 20 and a.u., the excitonic phase is found to be stable. We do not find that the anti-ferromagnetic Wigner crystal is stable over the considered range of r s and d. We also find that as r s increases, the critical layer separations for Wigner crystallization increase.
Protein crystal growth and the International Space Station
NASA Technical Reports Server (NTRS)
DeLucas, L. J.; Moore, K. M.; Long, M. M.
1999-01-01
Protein structural information plays a key role in understanding biological structure-function relationships and in the development of new pharmaceuticals for both chronic and infectious diseases. The Center for Macromolecular Crystallography (CMC) has devoted considerable effort studying the fundamental processes involved in macromolecular crystal growth both in a 1-g and microgravity environment. Results from experiments performed on more than 35 U.S. space shuttle flights have clearly indicated that microgravity can provide a beneficial environment for macromolecular crystal growth. This research has led to the development of a new generation of pharmaceuticals that are currently in preclinical or clinical trials for diseases such as cutaneous T-cell lymphoma, psoriasis, rheumatoid arthritis, AIDS, influenza, stroke and other cardiovascular complications. The International Space Station (ISS) provides an opportunity to have complete crystallographic capability on orbit, which was previously not possible with the space shuttle orbiter. As envisioned, the x-ray Crystallography Facility (XCF) will be a complete facility for growing protein crystals; selecting, harvesting, and mounting sample crystals for x-ray diffraction; cryo-freezing mounted crystals if necessary; performing x-ray diffraction studies; and downlinking the data for use by crystallographers on the ground. Other advantages of such a facility include crystal characterization so that iterations in the crystal growth conditions can be made, thereby optimizing the final crystals produced in a three month interval on the ISS.
NASA Technical Reports Server (NTRS)
Bugg, Charles E.
1993-01-01
Proteins account for 50% or more of the dry weight of most living systems and play a crucial role in virtually all biological processes. Since the specific functions of essentially all biological molecules are determined by their three-dimensional structures, it is obvious that a detailed understanding of the structural makeup of a protein is essential to any systematic research pertaining to it. At the present time, protein crystallography has no substitute, it is the only technique available for elucidating the atomic arrangements within complicated biological molecules. Most macromolecules are extremely difficult to crystallize, and many otherwise exciting and promising projects have terminated at the crystal growth stage. There is a pressing need to better understand protein crystal growth, and to develop new techniques that can be used to enhance the size and quality of protein crystals. There are several aspects of microgravity that might be exploited to enhance protein crystal growth. The major factor that might be expected to alter crystal growth processes in space is the elimination of density-driven convective flow. Another factor that can be readily controlled in the absence of gravity is the sedimentation of growing crystal in a gravitational field. Another potential advantage of microgravity for protein crystal growth is the option of doing containerless crystal growth. One can readily understand why the microgravity environment established by Earth-orbiting vehicles is perceived to offer unique opportunities for the protein crystallographer. The near term objectives of the Protein Crystal Growth in a Microgravity Environment (PCG/ME) project is to continue to improve the techniques, procedures, and hardware systems used to grow protein crystals in Earth orbit.
NASA Technical Reports Server (NTRS)
Steiner, B.; Dobbyn, R.; Black, D.; Burdette, H.; Kuriyama, M.; Spal, R.; Vandenberg, L.; Fripp, A.; Simchick, R.; Lal, R.
1991-01-01
Irregularities found in three crystals grown in space, in four crystals grown entirely on the ground were examined and compared. Irregularities were observed in mercuric iodide, lead tin telluride, triglycine sulfate, and gallium arsenide by high resolution synchrotron x radiation diffraction imaging. Radiation detectors made from mercuric iodide crystals grown in microgravity were reported to perform far better than conventional detectors grown from the same material under full gravity. Effort is now underway to reproduce these 'space' crystals, optimize their properties, and extend comparable superiority to other types of materials.
Single crystal growth by gel technique and characterization of lithium hydrogen tartrate
NASA Astrophysics Data System (ADS)
Ahmad, Nazir; Ahmad, M. M.; Kotru, P. N.
2015-02-01
Single crystal growth of lithium hydrogen tartrate by gel encapsulation technique is reported. Dependence of crystal count on gel density, gel pH, reactant concentration and temperature are studied and the optimum conditions for these crystals are worked out. The stoichiometric composition of the grown crystals is determined using EDAX/AES and CH analysis. The grown crystals are characterized by X-ray diffraction, FTIR and Uv-Visible spectroscopy. It is established that crystal falls under orthorhombic system and space group P222 with the cell parameters as: a=10.971 Å, b=13.125 Å and c=5.101 Å; α=90.5o, β=γ=90°. The morphology of the crystals as revealed by SEM is illustrated. Crystallite size, micro strain, dislocation density and distortion parameters are calculated from the powder XRD results of the crystal. UV-vis spectroscopy shows indirect allowed transition with an optical band gap of 4.83 eV. The crystals are also shown to have high transmittance in the entire visible region. Dependence of dielectric constant, dielectric loss and conductivity on frequency of the applied ac field is analyzed. The frequency-dependent real part of the complex ac conductivity is found to follow the universal dielectric response: σac (ω) ωs. The trend in the variation of frequency exponent with frequency corroborates the fact that correlated barrier hopping is the dominant charge-transport mechanism in the present system.
The study of crystals for space processing and the effect of o-gravity
NASA Technical Reports Server (NTRS)
Lal, R. B.
1977-01-01
The mechanism of crystal growth was studied by solution technique and how it was affected by space environment. Investigation was made as to how space processing methods are used to improve the promising candidate materials for different devices.
NASA Technical Reports Server (NTRS)
Achari, Aniruddha; Roeber, Dana F.; Barnes, Cindy L.; Kundrot, Craig E.; Stinson, Thomas N. (Technical Monitor)
2002-01-01
Protein Crystallization Apparatus in Microgravity (PCAM) trays have been used in Shuttle missions to crystallize proteins in a microgravity environment. The crystallization experiments are 'sitting drops' similar to that in Cryschem trays, but the reservoir solution is soaked in a wick. From early 2001, crystallization experiments are conducted on the International Space Station using mission durations of months rather than two weeks on previous shuttle missions. Experiments were set up in April 2001 on Flight 6A to characterize the time crystallization experiments will take to reach equilibrium in a microgravity environment using salts, polyethylene glycols and an organic solvent as precipitants. The experiments were set up to gather data for a series of days of activation with different droplet volumes and precipitants. The experimental set up on ISS and results of this study will be presented. These results will help future users of PCAM to choose precipitants to optimize crystallization conditions for their target macromolecules for a particular mission with known mission duration. Changes in crystal morphology and size between the ground and space grown crystals of a protein and a protein -DNA complex flown on the same mission will also be presented.
Terrestrial photovoltaic collector technology trends
NASA Technical Reports Server (NTRS)
Shimada, K.; Costogue, E.
1984-01-01
Following the path of space PV collector development in its early stages, terrestrial PV technologies based upon single-crystal silicon have matured rapidly. Currently, terrestrial PV cells with efficiencies approaching space cell efficiencies are being fabricated into modules at a fraction of the space PV module cost. New materials, including CuInSe2 and amorphous silicon, are being developed for lowering the cost, and multijunction materials for achieving higher efficiency. Large grid-interactive, tracking flat-plate power systems and concentrator PV systems totaling about 10 MW, are already in operation. Collector technology development both flat-plate and concentrator, will continue under an extensive government and private industry partnership.
Pothineni, Sudhir Babu; Venugopalan, Nagarajan; Ogata, Craig M.; Hilgart, Mark C.; Stepanov, Sergey; Sanishvili, Ruslan; Becker, Michael; Winter, Graeme; Sauter, Nicholas K.; Smith, Janet L.; Fischetti, Robert F.
2014-01-01
The calculation of single- and multi-crystal data collection strategies and a data processing pipeline have been tightly integrated into the macromolecular crystallographic data acquisition and beamline control software JBluIce. Both tasks employ wrapper scripts around existing crystallographic software. JBluIce executes scripts through a distributed resource management system to make efficient use of all available computing resources through parallel processing. The JBluIce single-crystal data collection strategy feature uses a choice of strategy programs to help users rank sample crystals and collect data. The strategy results can be conveniently exported to a data collection run. The JBluIce multi-crystal strategy feature calculates a collection strategy to optimize coverage of reciprocal space in cases where incomplete data are available from previous samples. The JBluIce data processing runs simultaneously with data collection using a choice of data reduction wrappers for integration and scaling of newly collected data, with an option for merging with pre-existing data. Data are processed separately if collected from multiple sites on a crystal or from multiple crystals, then scaled and merged. Results from all strategy and processing calculations are displayed in relevant tabs of JBluIce. PMID:25484844
Pothineni, Sudhir Babu; Venugopalan, Nagarajan; Ogata, Craig M.; ...
2014-11-18
The calculation of single- and multi-crystal data collection strategies and a data processing pipeline have been tightly integrated into the macromolecular crystallographic data acquisition and beamline control software JBluIce. Both tasks employ wrapper scripts around existing crystallographic software. JBluIce executes scripts through a distributed resource management system to make efficient use of all available computing resources through parallel processing. The JBluIce single-crystal data collection strategy feature uses a choice of strategy programs to help users rank sample crystals and collect data. The strategy results can be conveniently exported to a data collection run. The JBluIce multi-crystal strategy feature calculates amore » collection strategy to optimize coverage of reciprocal space in cases where incomplete data are available from previous samples. The JBluIce data processing runs simultaneously with data collection using a choice of data reduction wrappers for integration and scaling of newly collected data, with an option for merging with pre-existing data. Data are processed separately if collected from multiple sites on a crystal or from multiple crystals, then scaled and merged. Results from all strategy and processing calculations are displayed in relevant tabs of JBluIce.« less
The 1994 NASA/USRA/ADP Design Projects
NASA Technical Reports Server (NTRS)
Cruse, Thomas; Richardson, Joseph; Tryon, Robert
1994-01-01
The NASA/USRA/ADP Design Projects from Vanderbilt University, Department of Mechanical Engineering (1994) are enclosed in this final report. Design projects include: (1) Protein Crystal Growth, both facilities and methodology; (2) ACES Deployable Space Boom; (3) Hybrid Launch System designs for both manned and unmanned systems; (4) LH2 Fuel Tank design (SSTO); (5) SSTO design; and (6) Pressure Tank Feed System design.
Artificial Hip Simulator with Crystal Models
1966-06-21
Robert Johnson, top, sets the lubricant flow while Donald Buckley adjusts the bearing specimen on an artificial hip simulator at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The simulator was supplemented by large crystal lattice models to demonstrate the composition of different bearing alloys. This this image by NASA photographer Paul Riedel was used for the cover of the August 15, 1966 edition of McGraw-Hill Product Engineering. Johnson was chief of Lubrication Branch and Buckley head of the Space Environment Lubrication Section in the Fluid System Components Division. In 1962 they began studying the molecular structure of metals. Their friction and wear testing revealed that the optimal structure for metal bearings was a hexagonal crystal structure with proper molecular space. Bearing manufacturers traditionally preferred cubic structures over hexagonal arrangements. Buckley and Johnson found that even though the hexagonal structural was not as inherently strong as its cubic counterpart, it was less likely to cause a catastrophic failure. The Lewis researchers concentrated their efforts on cobalt-molybdenum and titanium alloys for high temperatures applications. The alloys had a number of possible uses, included prosthetics. The alloys were similar in composition to the commercial alloys used for prosthetics, but employed the longer lasting hexagonal structure.
NASA Technical Reports Server (NTRS)
Wingard, Charles Doug; Munafo, Paul M. (Technical Monitor)
2002-01-01
Protein crystals are grown in microgravity experiments inside the Space Shuttle during orbit. Such crystals are basically grown in a five-component system containing a salt, buffer, polymer, organic and water. During these experiments, a number of different polymeric containment materials must be compatible with up to hundreds of different PCG solutions in various concentrations for durations up to 180 days. When such compatibility experiments are performed at NASA/MSFC (Marshall Space Flight Center) simultaneously on containment material samples immersed in various solutions in vials, the samples are rather small out of necessity. DMA4 modulus was often used as the primary screening parameter for such small samples as a pass/fail criterion for incompatibility issues. In particular, the TA Instruments DMA 2980 film tension clamp was used to test rubber O-rings as small in I.D. as 0.091 in. by cutting through the cross-section at one place, then clamping the stretched linear cord stock at each end. The film tension clamp was also used to successfully test short length samples of medical/surgical grade tubing with an O.D. of 0.125 in.
NASA Astrophysics Data System (ADS)
Garcia, Humberto C.; Cunha, Ronaldo T.; Diniz, Renata; de Oliveira, Luiz Fernando C.
2012-02-01
In this study, the synthesis, spectroscopic properties (infrared and Raman) and crystal structures of two new compounds co-crystal and crystal named HASbpa (1) and [Co(bpa)(H2O)4]AS2ṡ4H2O (2) have been reported, where bpa is trans-1,2-bis(4-pyridyl)ethane, HAS is 4-aminosalicylic acid and AS- is aminosalicylate anion. The crystalline arrangement of the compound 1 exhibits a triclinic system with space group P1¯. The formation of a structure known as co-crystal, composed by building blocks in their neutral form; being the first work of this type involving the HAS and nitrogen ligand as bpa. For compound 2, a monoclinic system was observed with P21/c space group. The crystalline arrangement of the structure consisted of a covalent one-dimensional cationic [Co(bpa)(H2O)4]2+ chain, which interacts by hydrogen bonding, π-stacking and electrostatic interactions with aminosalicylate anions and water molecules that were trapped in the crystal. These interactions form supramolecular cavities denominated as pseudo honeycombs. For compound 1, the infrared spectrum revealed the presence of bands at 1643 and 1601 cm-1 assigned to the stretching mode of CO [ν(CO)] and CC/CN groups [ν(CC/CN)]. For the Raman spectrum, these same modes appear around 1644 and 1602 cm-1 related to HAS and bpa blocks, respectively. For compound 2, the largest displacement of the bands compared to free ligand suggested the formation of covalent bonds between bpa ligand and metallic site and loss of the proton in HAS molecule. In the infrared spectrum we can observe the presence of bands around 1635 and 1618 cm-1 attributed to the stretching ν(COO-) and ν(CC/CN), for the Raman spectrum these same modes appear around 1631 and 1619 cm-1 related to AS- and bpa ligand respectively.
Crystallization of Chicken Egg White Lysozyme from Assorted Sulfate Salts
NASA Technical Reports Server (NTRS)
Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.
1999-01-01
Chicken egg white lysozyme has been found to crystallize from ammonium, sodium, potassium, rubidium, magnesium, and manganese sulfates at acidic and basic pH, with protein concentrations from 60 to 190 mg/ml. Crystals have also been grown at 4 C in the absence of any other added salts using isoionic lysozyme which was titrated to pH 4.6 with dilute sulfuric acid. Four different crystal forms have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed. Crystals grown at 15 C were generally tetragonal, with space group P4(sub 3)2(sub 1)2. Crystallization at 20 C typically resulted in the formation of orthorhombic crystals, space group P2(sub 1)2(sub 1)2(sub 1). The tetragonal reversible reaction orthorhombic transition appeared to be a function of both the temperature and protein concentration, occurring between 15 and 20 C and between 100 and 125 mg/ml protein concentration. Crystallization from 1.2 M magnesium sulfate at pH 7.8 gave a trigonal crystal, space group P3(sub 1)2(sub 1), a = b = 87.4, c = 73.7, gamma = 120 deg, which diffracted to 2.8 A. Crystallization from ammonium sulfate at pH 4.6, generally at lower temperatures, was also found to result in a monoclinic form. space group C2, a = 65.6, b = 95.0, c = 41.2, beta = 119.2 deg. A crystal of approximately 0.2 x 0.2 x 0.5 mm grown from bulk solution diffracted to approximately 3.5 A.
NASA Technical Reports Server (NTRS)
1996-01-01
Teledyne Brown developed a computer-based interactive multimedia training system for use with the Crystal Growth Furnace in the U.S. Microgravity Laboratory-2 mission on the Space Shuttle. Teledyne Brown commercialized the system and customized it for PPG Industries Aircraft Products. The system challenges learners with role-playing scenarios and software-driven simulations engaging all the senses using text, video, animation, voice, sounds and music. The transfer of this technology to commercial industrial process training has resulted in significant improvements in effectiveness, standardization, and quality control, as well as cost reductions over the usual classroom and on-the- job training approaches.
Astronaut Peggy Whitson Installs SUBSA Experiment
NASA Technical Reports Server (NTRS)
2002-01-01
Expedition Five flight engineer Peggy Whitson is shown installing the Solidification Using a Baffle in Sealed Ampoules (SUBSA) experiment in the Microgravity Science Glovebox (MSG) in the Destiny laboratory aboard the International Space Station (ISS). SUBSA examines the solidification of semiconductor crystals from a melted material. Semiconductor crystals are used for many products that touch our everyday lives. They are found in computer chips, integrated circuits, and a multitude of other electronic devices, such as sensors for medical imaging equipment and detectors of nuclear radiation. Materials scientists want to make better semiconductor crystals to be able to further reduce the size of high-tech devices. In the microgravity environment, convection and sedimentation are reduced, so fluids do not remove and deform. Thus, space laboratories provide an ideal environment of studying solidification from the melt. This investigation is expected to determine the mechanism causing fluid motion during production of semiconductors in space. It will provide insight into the role of the melt motion in production of semiconductor crystals, advancing our knowledge of the crystal growth process. This could lead to a reduction of defects in semiconductor crystals produced in space and on Earth.
Fac-Re(bpy)(CO){sub 3}(COOMe): A model metallocarboxylate complex of rhenium with a bipyridyl ligand
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gibson, D.H.; Sleadd, B.A.; Vij, A.
1999-05-01
The title compound fac-(2,2{prime}-bipyridyl)(carbomethoxy)rhenium tricarbonyl, crystallizes in the monoclinic system, space group P2{sub 1}/c with the following crystal data: a = 8.37551(1), b = 6.6934(1), c = 26.2098(1) {angstrom}, V({angstrom}{sup 3}) = 1,535.93(3), Z = 4, and {beta} = 90.0971(2). The metal environment is slightly distorted octahedral with a chelating bipyridyl ligand and a facial arrangement of the carbon monoxide ligands.
NASA Technical Reports Server (NTRS)
Oliver, Michael J.
2014-01-01
The National Aeronautics and Space Administration (NASA) conducted a full scale ice crystal icing turbofan engine test using an obsolete Allied Signal ALF502-R5 engine in the Propulsion Systems Laboratory (PSL) at NASA Glenn Research Center. The test article used was the exact engine that experienced a loss of power event after the ingestion of ice crystals while operating at high altitude during a 1997 Honeywell flight test campaign investigating the turbofan engine ice crystal icing phenomena. The test plan included test points conducted at the known flight test campaign field event pressure altitude and at various pressure altitudes ranging from low to high throughout the engine operating envelope. The test article experienced a loss of power event at each of the altitudes tested. For each pressure altitude test point conducted the ambient static temperature was predicted using a NASA engine icing risk computer model for the given ambient static pressure while maintaining the engine speed.
Direct observation of interface instability during crystal growth
NASA Technical Reports Server (NTRS)
Tiller, W. A.; Feigelson, R. S.; Elwell, D.
1982-01-01
The general aim of this investigation was to study interface stability and solute segregation phenomena during crystallization of a model system. Emphasis was to be placed on direct observational studies partly because this offered the possibility at a later stage of performing related experiments under substantially convection-free conditions in the space shuttle. The major achievements described in this report are: (1) the development of a new model system for fundamental studies of crystal growth from the melt and the measurement of a range of material parameters necessary for comparison of experiment with theory. (2) The introduction of a new method of measuring segregation coefficient using absorption of a laser beam by the liquid phase. (3) The comparison of segregation in crystals grown by gradient freezing and by pulling from the melt. (4) The introduction into the theory of solute segregation of an interface field term and comparison with experiment. (5) The introduction of the interface field term into the theories of constitutional supercooling and morphological stability and assessment of its importance.
Crystal Growth Team in the Spacelab Payload Operations Control Center (SL POCC) During the STS-42
NASA Technical Reports Server (NTRS)
1992-01-01
The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Crystal Growth team in the SL POCC during STS-42, IML-1 mission.
Organic Crystal Growth Facility (OCGF) and Radiation Monitoring Container Device (RMCD) Groups in
NASA Technical Reports Server (NTRS)
1992-01-01
The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured are activities of the Organic Crystal Growth Facility (OCGF) and Radiation Monitoring Container Device (RMCD) groups in the SL POCC during the IML-1 mission.
NASA Astrophysics Data System (ADS)
Arivuselvi, R.; Babu, P. Ramesh
2018-03-01
Borates family crystals were plays vital role in the field of non linear optics (NLO) due to needs of wide range of applications. In this report, NLO crystals (potassium penta borate tetra hydrate (KB5H8O12) are grown by slow evaporation method at room temperature (28° C) and studied their physical properties. The harvested single crystals are transparent with the dimension of 12 × 10 × 6 mm3 and colourless. X-ray diffraction of single crystals reveals that the grown crystal belongs to orthorhombic system with non-centrosymmetric space group Pba2. All the absorbed functional groups are present in the order of inorganic compounds expect 1688 cm-1 because of water (Osbnd H sbnd O blending) molecule present in the pristine. Crystals show transparent in the entire visible region with 5.9 eV optical band gap and also it shows excellence in both second and third order nonlinear optical properties. Crystals can withstand upto 154 °C without any phase changes which is observed using thermal (TGA/DTA) analysis.
NASA Astrophysics Data System (ADS)
Renugadevi, R.; Kesavasamy, R.
2015-09-01
The growth of organic nonlinear optical (NLO) crystal 2-amino-5-chloropyridinium trichloroacetate (2A5CPTCA) has been synthesized and single crystals have been grown from methanol solvent by slow evaporation technique. The grown crystals were subjected to various characterization analyses in order to find out the suitability for device fabrication. Single crystal X-ray diffraction analysis reveals that 2A5CPTCA crystallizes in monoclinic system with the space group Cc. The grown crystal was further characterized by Fourier transform infrared spectral analysis to find out the functional groups. The nuclear magnetic resonance spectroscopy is a research technique that exploits the magnetic properties of certain atomic nuclei. The optical transparency window in the visible and near-IR (200--1100 nm) regions was found to be good for NLO applications. Thermogravimetric analysis and differential thermal analysis were used to study its thermal properties. The powder second harmonic generation efficiency measurement with Nd:YAG laser (1064 nm) radiation shows that the highest value when compared with the standard potassium dihydrogen phosphate crystal.
NASA Technical Reports Server (NTRS)
Begley, David L. (Editor); Seery, Bernard D. (Editor)
1991-01-01
The present volume on free-space laser communication technologies discusses system analysis, performance, and applications, pointing, acquisition, and tracking in beam control, laboratory demonstration systems, and transmitter and critical component technologies. Attention is given to a space station laser communication transceiver, meeting intersatellite links mission requirements by an adequate optical terminal design, an optical approach to proximity-operations communications for Space Station Freedom, and optical space-to-ground link availability assessment and diversity requirements. Topics addressed include nonmechanical steering of laser beams by multiple aperture antennas, a free-space simulator for laser transmission, heterodyne acquisition and tracking in a free-space diode laser link, and laser terminal attitude determination via autonomous star tracking. Also discussed are stability considerations in relay lens design for optical communications, liquid crystals for lasercom applications, and narrowband optical interference filters.
Crystal growth, characterization and theoretical studies of 4-aminopyridinium picrate
NASA Astrophysics Data System (ADS)
Aditya Prasad, A.; Muthu, K.; Rajasekar, M.; Meenatchi, V.; Meenakshisundaram, S. P.
2015-01-01
Single crystals of 4-aminopyridinium picrate (APP) were grown by slow evaporation of a mixed solvent system methanol-acetone (1:1, v/v) containing equimolar quantities of 4-aminopyridine and picric acid. Structure is elucidated by single crystal XRD analysis and the crystal belongs to monoclinic system with four molecules in the unit cell (space group P21/c) and the cell parameter values are, a = 8.513 Å (±0.015), b = 11.33 Å (±0.02), c = 14.33 Å (±0.03) and β = 104.15° (±0.019), V = 1340 A3 (±6) with refined R factors R1 = 0.0053 and wR2 = 0.0126. The electron density mapping is interpreted to find coordinates for each atom in the crystallized molecules. The various functional groups present in the molecule are confirmed by FT-IR analysis. UV-visible spectral analysis was used to determine the band gap energy of 4-aminopyridinium picrate. Powder X-ray diffraction pattern reveals the crystallinity of the as-grown crystal and it closely resembles the simulated XRD from the single crystal XRD analysis. Scanning electron microscopy reveals the surface morphology of the grown crystal. Optimized geometry is derived by Hartree-Fock theory calculations and the first-order molecular hyperpolarizability (β), theoretically calculated bond length, bond angles and excited state energy from theoretical UV-vis spectrum were estimated.
Pandi, P; Peramaiyan, G; Kumar, M Krishna; Kumar, R Mohan; Jayavel, R
2012-03-01
Synthesis and growth of a novel organic nonlinear optical (NLO) crystal of 4-aminopyridinium maleate (4APM) in larger size by the slow evaporation solution growth technique are reported. Single crystal and powder X-ray diffraction analyses reveal that 4APM crystallizes in monoclinic system with space group P2(1) with cell parameters a=8.140(4)Å, b=5.457(5)Å, c=10.926(10)Å and volume=481.4(7)Å(3). The grown crystal has been characterized by Fourier transform infrared and UV-visible spectral analyses. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) have been carried out to study its thermal properties. Dielectric measurements have been carried out to study the distribution of charges within the crystal. The mechanical strength of the crystal has been studied by using Vickers' microhardness test. The etching studies have been carried out on the grown crystal. The Kurtz and Perry powder SHG technique confirms the NLO property of the grown crystal and the SHG efficiency of 4APM was found to be 4.8 times greater than that of KDP crystal. Copyright © 2011 Elsevier B.V. All rights reserved.
Sadhasivam, S; Rajesh, Narayana Perumal
2014-09-15
Organic single crystal of 2-hydroxy biphenyl (2-HB) was grown by top seeded melt growth method. Scanning electron microscopy studies has been carried out on the surface of the grown crystals to investigate the nature of growth and defects. The crystalline perfection and lattice parameters of 2-HB has been determined by single crystal XRD analysis and it belongs to orthorhombic crystal system with space group Fdd2. The functional groups and molecular associations were confirmed by FT-IR. The optical characteristics such as cut-off and transmittance were carried out using UV-Vis-NIR spectra. Absence of absorption in the region between 320 and 1100 nm makes the grown crystal desirable to optical applications. Thermal stability of grown crystals was characterized by thermogravimetric (TGA), differential thermal analysis (DTA) and differential scanning calorimetric (DSC) analyses. Broadband dielectric studies reveals that dielectric constant of grown crystal is low. The resistivity of grown crystal was studied by impedance analysis. The second harmonic generation intensity of 3.8 mJ was studied. The grown crystal belongs to soft material studied by hardness test. Copyright © 2014 Elsevier B.V. All rights reserved.
Krishnan, P; Gayathri, K; Bhagavannarayana, G; Gunasekaran, S; Anbalagan, G
2013-02-01
Monohydrate piperazine hydrogen phosphate (MPHP), a semi organic nonlinear optical material has been synthesized and single crystals were grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction study on grown crystal reveals that they belong to monoclinic crystal system with space group P2(1)/c; (a=6.39Å; b=12.22Å; c=11.16Å; β=97.14°; V=864Å(3)). The structural perfection of the grown crystal was analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. FTIR spectrum confirms the presence of the functional groups in synthesized material. UV-Vis spectrum indicates that the crystal is transparent in the entire visible region with a lower cut off wavelength of 387 nm. The variation of dielectric properties of the grown crystal with respect to frequency has been investigated at different temperatures. Thermal analysis carried out on the MPHP crystal shows that the crystal is stable up to 135°C. Relative powder second harmonic generation efficiency tested by Kurtz-Perry powder technique, which was about 0.638 times that of Potassium dihydrogen phosphate. Copyright © 2012 Elsevier B.V. All rights reserved.
Commander Bowersox Tends to Zeolite Crystal Samples Aboard Space Station
NASA Technical Reports Server (NTRS)
2003-01-01
Expedition Six Commander Ken Bowersox spins Zeolite Crystal Growth sample tubes to eliminate bubbles that could affect crystal formation in preparation of a 15 day experiment aboard the International Space Station (ISS). Zeolites are hard as rock, yet are able to absorb liquids and gases like a sponge. By using the ISS microgravity environment to grow better, larger crystals, NASA and its commercial partners hope to improve petroleum manufacturing and other processes.
Decades of Data: Extracting Trends from Microgravity Crystallization History
NASA Technical Reports Server (NTRS)
Judge, Russell A.; Snell, Edward H.; Kephart, Richard; vanderWoerd, Mark; Curreri, Peter A. (Technical Monitor)
2002-01-01
The reduced acceleration environment of an orbiting spacecraft has been posited as an ideal environment for biological crystal growth since buoyancy driven convection and sedimentation are greatly reduced. Since the first sounding rocket flight in 1981 many crystallization experiments have flown with some showing improvement and others not. To further explore macromolecule crystal improvement in microgravity we have accumulated data from published reports and reports submitted by individual investigators to NASA, forming a database called BIOSEArCH (Biological Space Experiment Archive of Crystallization History). To date it contains information from 63 missions including, the Space Shuttle program, unmanned satellites, the Russian Space Station MIR and sounding rocket experiments, containing reports for more than 736 macromolecule experiments. While it is not at this point in time a comprehensive record of all flight crystallization experimental results, there is however sufficient information for emerging trends to be identified. These trends will be highlighted.
Towards true 3D textural analysis; using your crystal mush wisely.
NASA Astrophysics Data System (ADS)
Jerram, D. A.; Morgan, D. J.; Pankhurst, M. J.
2014-12-01
The crystal cargo that is found in volcanic and plutonic rocks contains a wealth of information about magmatic mush processes, crystallisation history, crystal entrainment and recycling. Phenocryst populations predominantly record episodes of growth/nucleation and bulk geochemical changes within an evolving crystal-melt body. Ante- and xeno-crysts provide useful clues to the nature of mush interaction with wall rock and with principal magma(s). Furthermore, crystal evolutions (core to rim) record pathways through pressure, temperature and compositional space. These can often illustrate complex recycling within systems, describing the plumbing architecture. Understanding this architecture underpins our knowledge of how igneous systems can interact with the crust, grow, freeze, re-mobilise and prime for eruption. Initially, 2D studies produced corrected 3D crystal size distributions to help provide information about nucleation and residence times. It immediately became clear that crystal shape is an important factor in determining the confidence placed upon 3D reconstructions of 2D data. Additionally studies utilised serial sections of medium- to coarse-grain-size populations which allowed 3D reconstruction using modelling software to be improved, since size and shape etc. can be directly constrained. Finally the advent of textural studies using X-ray tomography has revolutionised the way in which we can inspect the crystal cargo in mushy systems, allowing us to image in great detail crystal packing arrangements, 3D CSDs, shapes and orientations etc. The latest most innovative studies use X-ray micro-computed tomography to rapidly characterise chemical populations within the crystal cargo, adding a further dimension to this approach, and implies the ability to untangle magmatic chemical components to better understand their individual and combined evolution. In this contribution key examples of the different types of textural analysis techniques in 2D and 3D, including texture movie animations, are used from both plutonic and volcanic systems to highlight the roll of this approach towards a goal of true 3D textural analysis.
NASA Astrophysics Data System (ADS)
Long, Marianna M.; Bishop, John Bradford; Delucas, Lawrence J.; Nagabhushan, Tattanhalli L.; Reichert, Paul; Smith, G. David
1997-01-01
The Protein Crystal Growth Facility (PCF) is space-flight hardware that accommodates large scale protein crystal growth experiments using temperature change as the inductive step. Recent modifications include specialized instrumentation for monitoring crystal nucleation with laser light scattering. This paper reviews results from its first seven flights on the Space Shuttle, the last with laser light scattering instrumentation in place. The PCF's objective is twofold: (1) the production of high quality protein crystals for x-ray analysis and subsequent structure-based drug design and (2) preparation of a large quantity of relatively contaminant free crystals for use as time-release protein pharmaceuticals. The first three Shuttle flights with bovine insulin constituted the PCF's proof of concept, demonstrating that the space-grown crystals were larger and diffracted to higher resolution than their earth-grown counterparts. The later four PCF missions were used to grow recombinant human insulin crystals for x-ray analysis and continue productions trials aimed at the development of a processing facility for crystalline recombinant a-interferon.
Phase diagrams and crystal growth
NASA Astrophysics Data System (ADS)
Venkrbec, Jan
1980-04-01
Phase diagrams are briefly treated as generalized property-composition relationships, with respect to crystal technology optimization. The treatment is based on mutual interaction of three systems related to semiconductors: (a) the semiconducting material systems, (b0 the data bank, (c) the system of crystallization methods. A model is proposed enabling optimatization on the path from application requirements to the desired material. Further, several examples of the selection as to the composition of LED and laser diode material are given. Some of molten-solution-zone methods are being successfully introduced for this purpose. Common features of these methods, the application of phase diagrams, and their pecularities compared with other crystallization methods are illustrated by schematic diagrams and by examples. LPE methods, particularly the steady-state LPE methods such as Woodall's ISM and Nishizawa's TDM-CVP, and the CAM-S (Crystallization Method Providing Composition Autocontrol in Situ) have been chosen as examples. Another approach of exploiting phase diagrams for optimal material selection and for determination of growth condition before experimentation through a simple calculation is presented on InP-GaP solid solutions. Ternary phase diagrams are visualized in space through calculation and constructions based on the corresponding thermodynamic models and anaglyphs. These make it easy to observe and qualitatively analyze the crystallization of every composition. Phase diagrams can be also used as a powerful tool for the deduction of new crystallization methods. Eutectic crystallization is an example of such an approach where a modified molten-solution-zone method can give a sandwich structure with an abrupt concentration change. The concentration of a component can range from 0 to 100% in the different solid phases.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nakamura, Tsutomu; Ishikawa, Kazuhiko; Hagihara, Yoshihisa
The expression, purification and preliminary X-ray diffraction studies of a chitin-binding domain of the chitinase from P. furiosus are reported. The crystallization and preliminary X-ray diffraction analysis of the chitin-binding domain of chitinase from a hyperthermophilic archaeon, Pyrococcus furiosus, are reported. The recombinant protein was prepared using an Escherichia coli overexpression system and was crystallized by the hanging-drop vapour-diffusion method. An X-ray diffraction data set was collected to 1.70 Å resolution. The crystal belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2. The unit-cell parameters were determined to be a = b = 48.8, c = 85.0 Å.
Crystallization and preliminary crystallographic analysis of human common-type acylphosphatase
Yeung, Rachel C. Y.; Lam, Sonia Y.; Wong, Kam-Bo
2006-01-01
Human acylphosphatase, an 11 kDa enzyme that catalyzes the hydrolysis of carboxyl phosphate bonds, has been studied extensively as a model system for amyloid-fibril formation. However, the structure is still not known of any isoform of human acylphosphatase. Here, the crystallization and preliminary X-ray diffraction data analysis of human common-type acylphosphatase are reported. Crystals of human common-type acylphosphatase have been grown by the sitting-drop vapour-diffusion method at 289 K using polyethylene glycol 4000 as precipitant. Diffraction data were collected to 1.45 Å resolution at 100 K. The crystals belong to space group P212121, with unit-cell parameters a = 42.58, b = 47.23, c = 57.26 Å. PMID:16511269
NASA Astrophysics Data System (ADS)
Sharma, Raj Pal; Saini, Anju; Kumar, Santosh; Kumar, Jitendra; Sathishkumar, Ranganathan; Venugopalan, Paloth
2017-01-01
A new anionic copper(II) complex, (MeImH)2 [Cu(pfbz)4] (1) where, MeImH = 2-methylimidazolium and pfbz = pentafluorobenzoate has been isolated by reacting copper(II) sulfate pentahydrate, pentafluorobenzoic acid and 2-methylimidazole in ethanol: water mixture in 1:2:2 molar ratio. This complex 1 has been characterized by elemental analysis, thermogravimetric analysis, spectroscopic techniques (UV-Vis, FT-IR) and conductance measurements. The complex salt crystallizes in monoclinic crystal system with space group C2/c. Single crystal X-ray structure determination revealed the presence of discrete ions: [Cu(pfbz)4]2- anion and two 2-methylimidazolium cation (C4H7N2)+. The crystal lattice is stabilized by strong hydrogen bonding and F⋯F interactions between cationic-anionic and the anionic-anionic moieties respectively, besides π-π interactions.
Exploring the zone of anisotropy and broken symmetries in DNA-mediated nanoparticle crystallization.
O'Brien, Matthew N; Girard, Martin; Lin, Hai-Xin; Millan, Jaime A; Olvera de la Cruz, Monica; Lee, Byeongdu; Mirkin, Chad A
2016-09-20
In this work, we present a joint experimental and molecular dynamics simulations effort to understand and map the crystallization behavior of polyhedral nanoparticles assembled via the interaction of DNA surface ligands. In these systems, we systematically investigated the interplay between the effects of particle core (via the particle symmetry and particle size) and ligands (via the ligand length) on crystallization behavior. This investigation revealed rich phase diagrams, previously unobserved phase transitions in polyhedral crystallization behavior, and an unexpected symmetry breaking in the ligand distribution on a particle surface. To understand these results, we introduce the concept of a zone of anisotropy, or the portion of the phase space where the anisotropy of the particle is preserved in the crystallization behavior. Through comparison of the zone of anisotropy for each particle we develop a foundational roadmap to guide future investigations.
3D coherent X-ray diffractive imaging of an Individual colloidal crystal grain
NASA Astrophysics Data System (ADS)
Shabalin, A.; Meijer, J.-M.; Sprung, M.; Petukhov, A. V.; Vartanyants, I. A.
Self-assembled colloidal crystals represent an important model system to study nucleation phenomena and solid-solid phase transitions. They are attractive for applications in photonics and sensorics. We present results of a coherent x-ray diffractive imaging experiment performed on a single colloidal crystal grain. The full three-dimensional (3D) reciprocal space map measured by an azimuthal rotational scan contained several orders of Bragg reflections together with the coherent interference signal between them. Applying the iterative phase retrieval approach, the 3D structure of the crystal grain was reconstructed and positions of individual colloidal particles were resolved. We identified an exact stacking sequence of hexagonal close-packed layers including planar and linear defects. Our results open up a breakthrough in applications of coherent x-ray diffraction for visualization of the inner 3D structure of different mesoscopic materials, such as photonic crystals. Present address: University of California - San Diego, USA.
Crystal structure, thermal and optical properties of Benzimidazole benzimidazolium picrate crystal
NASA Astrophysics Data System (ADS)
Jagadesan, A.; Peramaiyan, G.; Srinivasan, T.; Kumar, R. Mohan; Arjunan, S.
2016-02-01
A new organic framework of benzimidazole with picric acid has been synthesized. A single crystal with a size of 38×10×4 mm3 was grown by a slow evaporation solution growth technique. X-ray diffraction study revealed that the BZP crystal belongs to triclinic system with space group P-1. High resolution X-ray diffraction study shows the absence of grain boundaries without any defects. The thermal stability and specific heat capacity of BZP were investigated by TG/DT and TG/DSC analyses. From the UV-vis-NIR spectral study, optical transmission window and band gap of BZP were found out. The nonlinear refractive index (n2) and third order susceptibility Re(χ(3)) values of BZP crystal are estimated to be 1.73×10-7 cm2/W and 1.26×10-5 esu, respectively using a Z-scan technique.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nguyen, Phoung-Hieu T.; Kemei, Moureen C.; Tan, Malinda S.
2016-10-15
Li{sub 4}MgOsO{sub 6} was synthesized by two different solid-state reaction procedures. The crystal structures were determined by X-ray powder diffraction technique and it was revealed that Li{sub 4}MgOsO{sub 6} crystallizes in two different crystal symmetries in ordered rock salt structure type, namely monoclinic C2/m and orthorhombic Fddd. The unit cell constants for the monoclinic system are a=5.1074(4) Å, b=8.8182(4) Å, c=5.0902(2) Å, and β=109.845(4)° and those of the orthorhombic structure are a=5.8485(1) Å, b=8.3821(1) Å, and c=17.6212(3) Å. In both systems, Os{sup 6+} ions reside exclusively in a specific crystallographic position while Li{sup +} and Mg{sup 2+} ions exhibit mixmore » occupancy. The temperature dependent magnetic susceptibility data for both S=1 osmate systems do not support the occurrence of any magnetic transition down to 2 K. The Curie–Weiss fit to the paramagnetic regime of the magnetic susceptibility data reveal highly negative θ value (−114.81 K and −121.87 K for C2/m and for Fddd systems, respectively), which are indicative of predominant antiferromagnetic (AFM) interactions in both systems. The experimental effective magnetic moment (μ{sub eff}) value for the monoclinic phase is 2.13 μB and that of the orthorhombic system is 2.34 μB. Due to the rather strong AFM interactions and lack of magnetic transition down to 2 K, both of these novel osmates are placed in the class of highly frustrated magnets. Low temperature magnetic susceptibility (below 2 K) and dynamic magnetic properties studies (μsr studies) are in order to better understand the magnetic ground states of these two polymorphs of Li{sub 4}MgOsO{sub 6}. - Graphical abstract: The structural transformation between two modifications of highly frustrated Li{sub 4}MgOsO{sub 6}. - Highlights: • Li4MgOsO{sub 6} was synthesized in two different crystal systems. • The monoclinic variant crystallizes in C2/m space group, while the orthorhombic version forms in Fddd space group. • The Os{sup 6+} ions are fully ordered while Li{sup +} and Mg{sup 2+} are mixed occupied. • These systems are the first Os{sup 6+} compounds in ordered NaCl structure type. • Both compounds exhibit high degree of geometric magnetic frustration.« less
NASA Astrophysics Data System (ADS)
Various papers on photovoltaics are presented. The general topics considered include: amorphous materials and cells; amorphous silicon-based solar cells and modules; amorphous silicon-based materials and processes; amorphous materials characterization; amorphous silicon; high-efficiency single crystal solar cells; multijunction and heterojunction cells; high-efficiency III-V cells; modeling and characterization of high-efficiency cells; LIPS flight experience; space mission requirements and technology; advanced space solar cell technology; space environmental effects and modeling; space solar cell and array technology; terrestrial systems and array technology; terrestrial utility and stand-alone applications and testing; terrestrial concentrator and storage technology; terrestrial stand-alone systems applications; terrestrial systems test and evaluation; terrestrial flatplate and concentrator technology; use of polycrystalline materials; polycrystalline II-VI compound solar cells; analysis of and fabrication procedures for compound solar cells.
Characterization of the Vectron PX-570 Crystal Oscillator for Use in Harsh Environments
NASA Technical Reports Server (NTRS)
Li, Jacob; Patterson, Richard L.; Hammoud, Ahmad
2012-01-01
Computing hardware, data-acquisition systems, communications systems, and many electronic control systems require well-controlled timing signals for proper and accurate operation. These signals are, in most cases, provided by circuits that employ crystal oscillators due to availability, cost, ease of operation, and accuracy. In some cases, the electronic systems are expected to survive and operate under harsh conditions that include exposure to extreme temperatures. These applications exist in terrestrial systems as well as in aerospace products. Well-logging, geothermal systems, and industrial process control are examples of ground-based applications, while distributed jet engine control in aircraft, space-based observatories (such as the James Webb Space Telescope), satellites, and lunar and planetary landers are typical environments where electronics are exposed to harsh operating conditions. To ensure these devices produce reliable results, the digital heartbeat from the oscillator must deliver a stable signal that is not affected by external temperature or other conditions. One such solution is a recently introduced commercial-off-the-shelf (COTS) oscillator, the PX-570 series from Vectron International. The oscillator was designed for high-temperature applications and as proof, the crystal oscillator was subjected to a wide suite of tests to determine its ruggedness for operation in harsh environments. The tests performed by Vectron included electrical characterization under wide range of temperature, accelerated life test/aging, shock and vibration, internal moisture analysis, ESD threshold, and latch-up testing. The parametric evaluation was performed on the oscillator's frequency, output signal rise and fall times, duty cycle, and supply current over the temperature range of -125 C to +230 C. The evaluations also determined the effects of thermal cycling and the oscillator's re-start capability at extreme hot and cold temperatures. These thermal cycling and restart tests were performed at the NASA Glenn Research Center. Overall, the crystal oscillator performed well and demonstrated very good frequency stability. This paper will discuss the test procedures and present details of the performance results.
Proceedings of the Workshop on an Electromagnetic Positioning System in Space
NASA Technical Reports Server (NTRS)
Oran, W. A. (Editor)
1978-01-01
A workshop was convened to help determine if sufficient justification existed to proceed with the design of an electromagnetic (EM) positioning device for use in space. Those in attendance included experts in crystal growth, nucleation phenomena, containerless processing techniques, properties of materials, metallurgical techniques, and glass technology. Specific areas mentioned included the study of metallic glasses and investigations of the properties of high temperature materials.
Procedures for analysis of debris relative to Space Shuttle systems
NASA Technical Reports Server (NTRS)
Kim, Hae Soo; Cummings, Virginia J.
1993-01-01
Debris samples collected from various Space Shuttle systems have been submitted to the Microchemical Analysis Branch. This investigation was initiated to develop optimal techniques for the analysis of debris. Optical microscopy provides information about the morphology and size of crystallites, particle sizes, amorphous phases, glass phases, and poorly crystallized materials. Scanning electron microscopy with energy dispersive spectrometry is utilized for information on surface morphology and qualitative elemental content of debris. Analytical electron microscopy with wavelength dispersive spectrometry provides information on the quantitative elemental content of debris.
Phatak, R; Gupta, S K; Krishnan, K; Sali, S K; Godbole, S V; Das, A
2014-02-28
Double perovskite type compounds of the formula BaA'LaTeO6 (A' = Na, K, Rb) were synthesized by solid state route and their crystal structures were determined by Rietveld analysis using powder X-ray diffraction and neutron diffraction data. Na compound crystallizes in the monoclinic system with P2₁/n space group whereas, K and Rb compounds crystallize in Fm3m space group. All the three compounds show rock salt type ordering at B site. Crystal structure analysis shows that La ion occupies A site in Na compound whereas, it occupies B site in K and Rb compounds according to the general formula of AA'BB'O6 for a double perovskite type compound. Effect of this crystallographic site swapping of the La ion was also observed in the photoluminescence study by doping Eu(3+) in La(3+) site. The large decrease in the intensity of the electric dipole ((5)D0-(7)F2) transition in the Rb compound compared to the Na compound indicates that Eu(3+) ion resides in the centrosymmetric octahedral environment in the Rb compound.
President Gerald Ford holds crystal manufactured in space during Skylab 4
NASA Technical Reports Server (NTRS)
1974-01-01
President Gerald R. Ford, center, holds encased crystal manufactured in space during Skylab 4. Dr. James C. Fletcher, left, NASA Administrator, explains the article to the Chief Executive as Dr. Harold Johnson of M.I.T. looks on. The indium-antimonide crystal was formed in Earth orbit on January 6, 1974, by the Skylab 4 astronauts.
Emergence of topological semimetals in gap closing in semiconductors without inversion symmetry.
Murakami, Shuichi; Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi
2017-05-01
A band gap for electronic states in crystals governs various properties of solids, such as transport, optical, and magnetic properties. Its estimation and control have been an important issue in solid-state physics. The band gap can be controlled externally by various parameters, such as pressure, atomic compositions, and external field. Sometimes, the gap even collapses by tuning some parameter. In the field of topological insulators, this closing of the gap at a time-reversal invariant momentum indicates a band inversion, that is, it leads to a topological phase transition from a normal insulator to a topological insulator. We show, through an exhaustive study on possible space groups, that the gap closing in inversion-asymmetric crystals is universal, in the sense that the gap closing always leads either to a Weyl semimetal or to a nodal-line semimetal. We consider three-dimensional spinful systems with time-reversal symmetry. The space group of the system and the wave vector at the gap closing uniquely determine which possibility occurs and where the gap-closing points or lines lie in the wave vector space after the closing of the gap. In particular, we show that an insulator-to-insulator transition never happens, which is in sharp contrast to inversion-symmetric systems.
NASA Astrophysics Data System (ADS)
Troć, R.; Gajek, Z.; Pikul, A.; Misiorek, H.; Colineau, E.; Wastin, F.
2013-07-01
The transport properties described previously [Troć , Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.85.224434 85, 224434 (2012)] as well as the magnetic and thermal properties presented in this paper, observed for single-crystalline UCu2Si2, are discussed by assuming a dual (localized-itinerant) scenario. The electronic states of the localized 5f electrons in UCu2Si2 are constructed using the effective Hamiltonian known for ionic systems, allowing us to treat the Coulomb, spin-orbital, and crystal-field interactions on equal footing. The space of parameters has been restricted in the initial steps with the aid of the angular overlap model approximation. The final crystal-field parameters, obtained from the refined steps of calculations, are relatively large (in absolute values), which we attribute to the hybridization characteristic of the metallic systems on the verge of localization. The proposed crystal-field model reproduces correctly with satisfactory accuracy the magnetic and thermal properties of UCu2Si2 in agreement also with the transport properties reported previously. Considerable crystal-field splitting of the ground multiplet of 2760 K is responsible for a large anisotropy in the magnetic behavior, observed in the whole temperature range explored.
Doubled heterogeneous crystal nucleation in sediments of hard sphere binary-mass mixtures
NASA Astrophysics Data System (ADS)
Löwen, Hartmut; Allahyarov, Elshad
2011-10-01
Crystallization during the sedimentation process of a binary colloidal hard spheres mixture is explored by Brownian dynamics computer simulations. The two species are different in buoyant mass but have the same interaction diameter. Starting from a completely mixed system in a finite container, gravity is suddenly turned on, and the crystallization process in the sample is monitored. If the Peclet numbers of the two species are both not too large, crystalline layers are formed at the bottom of the cell. The composition of lighter particles in the sedimented crystal is non-monotonic in the altitude: it is first increasing, then decreasing, and then increasing again. If one Peclet number is large and the other is small, we observe the occurrence of a doubled heterogeneous crystal nucleation process. First, crystalline layers are formed at the bottom container wall which are separated from an amorphous sediment. At the amorphous-fluid interface, a secondary crystal nucleation of layers is identified. This doubled heterogeneous nucleation can be verified in real-space experiments on colloidal mixtures.
NASA Astrophysics Data System (ADS)
Divya, R.; Nair, Lekshmi P.; Bijini, B. R.; Nair, C. M. K.; Babu, K. Rajendra
2018-05-01
Good quality prismatic crystals of industrially applicable corrosion inhibiting barium complex of 1,3,5-triazinane-2,4,6-trione have been grown by conventional gel method. The crystal structure, packing, and nature of bonds are revealed in the single crystal X-ray diffraction analysis. The crystal has a three-dimensional polymeric structure having a triclinic crystal system with the space group P-1. The powder X-ray diffraction analysis confirms its crystalline nature. The functional groups present in the crystal are identified by Fourier transform infrared spectroscopy. Elemental analysis confirms the stoichiometry of the elements present in the complex. Thermogravimetric analysis and differential thermal analysis reveal its good thermal stability. The optical properties like band gap, refractive index and extinction coefficient are evaluated from the UV-visible spectral analysis. The singular property of the material, corrosion inhibition efficiency achieved by the adsorption of the sample molecules is determined by the weight loss method.
Structural and spectroscopic investigation of glycinium oxalurate
NASA Astrophysics Data System (ADS)
Kavitha, T.; Pasupathi, G.; Marchewka, M. K.; Anbalagan, G.; Kanagathara, N.
2017-09-01
Glycinium oxalurate (GO) single crystals has been synthesized and grown by the slow solvent evaporation method at room temperature. Single crystal X-ray diffraction study confirms that GO crystal crystallizes in the monoclinic system with centrosymmetric space group P121/c1. The grown crystals are built up from single protonated glycinium residues and single dissociated oxalurate anions. A combination of ionic and donor-acceptor hydrogen-bond interactions linking together the glycine and oxaluric acid residues forms a three-dimensional network. Hydrogen bonded network present in the crystal gives notable vibrational effect. The molecular geometry, vibrational frequencies and intensity of the vibrational bands have been interpreted with the aid of structure optimization based on HF and density functional theory B3LYP methods with 6-311++G(d,p) basis set. Frontier molecular orbital energies and other related electronic properties are calculated. The natural bonding orbital (NBO) charges have been calculated and interpreted. The molecular electrostatic potential map has been constructed and discussed in detail.
JAXA protein crystallization in space: ongoing improvements for growing high-quality crystals
Takahashi, Sachiko; Ohta, Kazunori; Furubayashi, Naoki; Yan, Bin; Koga, Misako; Wada, Yoshio; Yamada, Mitsugu; Inaka, Koji; Tanaka, Hiroaki; Miyoshi, Hiroshi; Kobayashi, Tomoyuki; Kamigaichi, Shigeki
2013-01-01
The Japan Aerospace Exploration Agency (JAXA) started a high-quality protein crystal growth project, now called JAXA PCG, on the International Space Station (ISS) in 2002. Using the counter-diffusion technique, 14 sessions of experiments have been performed as of 2012 with 580 proteins crystallized in total. Over the course of these experiments, a user-friendly interface framework for high accessibility has been constructed and crystallization techniques improved; devices to maximize the use of the microgravity environment have been designed, resulting in some high-resolution crystal growth. If crystallization conditions were carefully fixed in ground-based experiments, high-quality protein crystals grew in microgravity in many experiments on the ISS, especially when a highly homogeneous protein sample and a viscous crystallization solution were employed. In this article, the current status of JAXA PCG is discussed, and a rational approach to high-quality protein crystal growth in microgravity based on numerical analyses is explained. PMID:24121350
Salt-induced aggregation of lysozyme: Implications for crystal growth
NASA Technical Reports Server (NTRS)
Wilson, Lori J.
1994-01-01
Crystallization of proteins is a prerequisite for structural analysis by x-ray crystallography. While improvements in protein crystals have been obtained in microgravity onboard the U.S. Space Shuttle, attempts to improve the crystal growth process both on the ground and in space have been limited by our lack of understanding of the mechanisms involved. Almost all proteins are crystallized with the aid of a precipitating agent. Many of the common precipitating agents are inorganic salts. An understanding of the role of salts on the aggregation of protein monomers is the key to the elucidation of the mechanisms involved in protein crystallization. In order for crystallization to occur individual molecules must self-associate into aggregates. Detection and characterization of aggregates in supersaturated protein solutions is the first step in understanding salt-induced crystallization.
Molecule diagram from space-grown crystals
NASA Technical Reports Server (NTRS)
2004-01-01
Researchers' at Hauptman-Woodward Medical Research Institute, in Buffalo, N.Y. have analyzed the molecular structures of insulin crystals grown during Space Shuttle experiments and are unlocking the mystery of how insulin works.
Vergara, Alessandro; Corvino, Ermanno; Sorrentino, Giosué; Piccolo, Chiara; Tortora, Alessandra; Carotenuto, Luigi; Mazzarella, Lelio; Zagari, Adriana
2002-10-01
Single chains of the collagen model polypeptide with sequence (Pro-Pro-Gly)(10), hereafter referred to as (PPG)(10), aggregate to form rod-shaped triple helices. Crystals of (PPG)(10) were grown in the Advanced Protein Crystallization Facility (APCF) both onboard the International Space Station (ISS) and on Earth. The experiments allow the direct comparison of four different crystallization environments for the first time: solution in microgravity ((g), agarose gel in (g, solution on earth, and gel on earth. Both on board and on ground, the crystal growth was monitored by a CCD video camera. The image analysis provided information on the spatial distribution of the crystals, their movement and their growth rate. The analysis of the distribution of crystals reveals that the crystallization process occurs as it does in batch conditions. Slow motions have been observed onboard the ISS. Different to Space-Shuttle experiment, the crystals onboard the ISS moved coherently and followed parallel trajectories. Growth rate and induction time are very similar both in gel and in solution, suggesting that the crystal growth rate is controlled by the kinetics at the interface under the used experimental conditions. These results provide the first data in the crystallogenesis of (PPG)(10), which is a representative member of non-globular, rod-like proteins.
Effect of Crystal Orientation on Analysis of Single-Crystal, Nickel-Based Turbine Blade Superalloys
NASA Technical Reports Server (NTRS)
Swanson, G. R.; Arakere, N. K.
2000-01-01
High-cycle fatigue-induced failures in turbine and turbopump blades is a pervasive problem. Single-crystal nickel turbine blades are used because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities. Single-crystal materials have highly orthotropic properties making the position of the crystal lattice relative to the part geometry a significant and complicating factor. A fatigue failure criterion based on the maximum shear stress amplitude on the 24 octahedral and 6 cube slip systems is presented for single-crystal nickel superalloys (FCC crystal). This criterion greatly reduces the scatter in uniaxial fatigue data for PWA 1493 at 1,200 F in air. Additionally, single-crystal turbine blades used in the Space Shuttle main engine high pressure fuel turbopump/alternate turbopump are modeled using a three-dimensional finite element (FE) model. This model accounts for material orthotrophy and crystal orientation. Fatigue life of the blade tip is computed using FE stress results and the failure criterion that was developed. Stress analysis results in the blade attachment region are also presented. Results demonstrate that control of crystallographic orientation has the potential to significantly increase a component's resistance to fatigue crack growth without adding additional weight or cost.
NASA Astrophysics Data System (ADS)
Dileep, M. S.; Suresh Kumar, H. M.
2018-04-01
A potentially useful nonlinear optical semi-organic single crystal of strontium L-ascorbate hexahydrate (SLAH) was grown by solution growth slow evaporation technique at room temperature. The grown crystal is semi transparent, yellowish in color with monoclinic crystal system having space group P21 and is stable up to 198 °C. Further, SLAH crystals were irradiated with gamma rays produced by 60Co with different doses of 10 KGy, 30 KGy and 50 KGy at room temperature and then studied the effect of gamma-rays on dielectric properties, optical absorption, microhardness and SHG efficiency. The absorption study reveals that the absorbance of the grown crystal is appeared to be low throughout the visible region with a lower cutoff wavelength of 277 nm and these parameters are not affected upon gamma irradiation. The luminescence intensity of the crystal is also not affected by the irradiation. There is noticeable changes were observed in dielectric properties and hardness of the materials for different doses of gamma irradiation. The second harmonic generation (SHG) efficiency of the grown crystal is 0.54 times that of the KDP crystal and is decreased moderately by increasing the dosage of gamma irradiation.
NASA Technical Reports Server (NTRS)
Heizer, Barbara L.
1992-01-01
The Crystals by Vapor Transport Experiment (CVTE) and Space Experiments Facility (SEF) are materials processing facilities designed and built for use on the Space Shuttle mid deck. The CVTE was built as a commercial facility owned by the Boeing Company. The SEF was built under contract to the UAH Center for Commercial Development of Space (CCDS). Both facilities include up to three furnaces capable of reaching 850 C minimum, stand-alone electronics and software, and independent cooling control. In addition, the CVTE includes a dedicated stowage locker for cameras, a laptop computer, and other ancillary equipment. Both systems are designed to fly in a Middeck Accommodations Rack (MAR), though the SEF is currently being integrated into a Spacehab rack. The CVTE hardware includes two transparent furnaces capable of achieving temperatures in the 850 to 870 C range. The transparent feature allows scientists/astronauts to directly observe and affect crystal growth both on the ground and in space. Cameras mounted to the rack provide photodocumentation of the crystal growth. The basic design of the furnace allows for modification to accommodate techniques other than vapor crystal growth. Early in the CVTE program, the decision was made to assign a principal scientist to develop the experiment plan, affect the hardware/software design, run the ground and flight research effort, and interface with the scientific community. The principal scientist is responsible to the program manager and is a critical member of the engineering development team. As a result of this decision, the hardware/experiment requirements were established in such a way as to balance the engineering and science demands on the equipment. Program schedules for hardware development, experiment definition and material selection, flight operations development and crew training, both ground support and astronauts, were all planned and carried out with the understanding that the success of the program science was as important as the hardware functionality. How the CVTE payload was designed and what it is capable of, the philosophy of including the scientists in design and operations decisions, and the lessons learned during the integration process are descussed.
Photonic crystal devices formed by a charged-particle beam
Lin, Shawn-Yu; Koops, Hans W. P.
2000-01-01
A photonic crystal device and method. The photonic crystal device comprises a substrate with at least one photonic crystal formed thereon by a charged-particle beam deposition method. Each photonic crystal comprises a plurality of spaced elements having a composition different from the substrate, and may further include one or more impurity elements substituted for spaced elements. Embodiments of the present invention may be provided as electromagnetic wave filters, polarizers, resonators, sources, mirrors, beam directors and antennas for use at wavelengths in the range from about 0.2 to 200 microns or longer. Additionally, photonic crystal devices may be provided with one or more electromagnetic waveguides adjacent to a photonic crystal for forming integrated electromagnetic circuits for use at optical, infrared, or millimeter-wave frequencies.
Structure cristalline de NaLiYb/sub 2/F/sub 8/: composes isotypes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dib, A.; Gorius, M.F.; Aleonard, S.
1986-11-15
NaLiYb/sub 2/F/sub 8/ crystallizes in the monoclinic system, space group C2/c, with a = 10.3516(9), b = 8.2069(9), c = 6,9674(7) A, ..beta.. = 90/sup 0/, Z = 4. The crystal structure has been solved from single crystal diffractometer measurements (AgK..cap alpha.. radiation) using Patterson and Fourier syntheses and refined by a least-squares method. The final R value is 0.021 for 1756 independent observed reflections. Two YbF/sub 8/ polyhedra share one of their edges to form Yb/sub 2/F/sub 14/ groups which are three-dimensionally linked and create cavities in which Na and Li are located. Yb/sub 2/F/sub 14/ groups share twomore » of their edges with these of one NaF/sub 7/ (or NaF/sub 9/ polyhedron to form Y/sub 2/NaF/sub 20/ blocks. As well, the structure may be described by the packing of planes formed by these two-dimensionally linked blocks. The description of this structure is compared with that ascribed to NaLiY/sub 2/F/sub 8/, which has been described in the monoclinic system, space group P2/sub 1//m, with a' = (a + b)/2, b' = c,c' = (b - a)/2, Z = 2. It is shown that positions of the atoms confer pseudoorthorhombic symmetry on the cell. Lattice parameters of isotypic compounds are given in the pseudoorthorhombic lattice and they are compared with those recently published with the structure described in the monoclinic system, space group P2/sub 1//m.« less
NASA Astrophysics Data System (ADS)
Yannouleas, Constantine; Landman, Uzi
2017-10-01
A constructive theoretical platform for the description of quantum space-time crystals uncovers for N interacting and ring-confined rotating particles the existence of low-lying states with proper space-time crystal behavior. The construction of the corresponding many-body trial wave functions proceeds first via symmetry breaking at the mean-field level followed by symmetry restoration using projection techniques. The ensuing correlated many-body wave functions are stationary states and preserve the rotational symmetries, and at the same time they reflect the point-group symmetries of the mean-field crystals. This behavior results in the emergence of sequences of select magic angular momenta Lm. For angular-momenta away from the magic values, the trial functions vanish. Symmetry breaking beyond the mean-field level can be induced by superpositions of such good-Lm many-body stationary states. We show that superposing a pair of adjacent magic angular momenta states leads to formation of special broken-symmetry states exhibiting quantum space-time-crystal behavior. In particular, the corresponding particle densities rotate around the ring, showing undamped and nondispersed periodic crystalline evolution in both space and time. The experimental synthesis of such quantum space-time-crystal wave packets is predicted to be favored in the vicinity of ground-state energy crossings of the Aharonov-Bohm-type spectra accessed via an externally applied, natural or synthetic, magnetic field. These results are illustrated here for Coulomb-repelling fermionic ions and for a lump of contact-interaction attracting bosons.
Quantum time crystal by decoherence: Proposal with an incommensurate charge density wave ring
NASA Astrophysics Data System (ADS)
Nakatsugawa, K.; Fujii, T.; Tanda, S.
2017-09-01
We show that time translation symmetry of a ring system with a macroscopic quantum ground state is broken by decoherence. In particular, we consider a ring-shaped incommensurate charge density wave (ICDW ring) threaded by a fluctuating magnetic flux: the Caldeira-Leggett model is used to model the fluctuating flux as a bath of harmonic oscillators. We show that the charge density expectation value of a quantized ICDW ring coupled to its environment oscillates periodically. The Hamiltonians considered in this model are time independent unlike "Floquet time crystals" considered recently. Our model forms a metastable quantum time crystal with a finite length in space and in time.
Overexpression, purification, crystallization and preliminary X-ray studies of Vibrio cholerae EpsG
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jens, Jason; Raghunathan, Kannan; Vago, Frank
2010-01-12
EpsG is the major pseudopilin protein of the Vibrio cholerae type II secretion system. An expression plasmid that encodes an N-terminally truncated form of EpsG with a C-terminal noncleavable His tag was constructed. Recombinant EpsG was expressed in Escherichia coli; the truncated protein was purified and crystallized by hanging-drop vapor diffusion against a reservoir containing 6 mM zinc sulfate, 60 mM MES pH 6.5, 15% PEG MME 550. The crystals diffracted X-rays to a resolution of 2.26 {angstrom} and belonged to space group P2{sub 1}, with unit-cell parameters a = 88.61, b = 70.02, c = 131.54 {angstrom}.
Chirp and temperature effects in parametric down conversion from crystals pumped at 800 nm
NASA Astrophysics Data System (ADS)
Sánchez-Lozano, X.; Wiechers, C.; Lucio, J. L.
2018-04-01
We consider spontaneous parametric down conversion from aperiodic poled crystals pumped at 800 nm. Our analyses account the effect of internal and external parameters, where, in the former, we include the crystal chirp and length, while in the latter temperature, also the pump chirp and other beam properties. The typical distribution produced is a pop-tab like structure in frequency-momentum space, and our results show that this system is a versatile light source, appropriated to manipulate the frequency and transverse momentum properties of the light produced. We briefly comment on the potential usefulness of the types of telecom wavelength light produced, in particular for quantum information applications.
STS-30 MS Cleave uses camcorder to record FEA-2 crystal growth
1989-05-08
STS030-10-002 (8 May 1989) --- STS-30 Mission Specialist Mary L. Cleave operates 8mm video camcorder at Fluids Experiment Apparatus 2 (FEA-2) (SK73-000102) unit located in aft middeck locker onboard Atlantis, Orbiter Vehicle (OV) 103. Two 8mm video camcorders are positioned above FEA-2 unit to record experiment titled "Floating Zone Crystal Growth and Purification". Rockwell International (RI) through its Space Transportation Systems Division, Downey, California, is engaged in a joint endeavor agreement (JEA) with NASA's Office of Commercial Programs in the field for floating zone crystal growth research. Utah State University Aggies decal appears on aft bulkhead above FEA-2 unit.
Growth, structural, spectroscopic and optical characterization of barium doped calcium tartrate
NASA Astrophysics Data System (ADS)
Verma, Seema; Raina, Bindu; Gupta, Vandana; Bamzai, K. K.
2018-05-01
Barium doped calcium tartrates synthesized by controlled diffusion using silica gel technique at ambient temperature was characterized by single crystal X-ray diffraction which establishes monoclinic crystal system with volume of the unit cell 923.97(10) Ǻ3 and the space group being P21. UV - Vis characterization gives various linear optical constants like absorption, transmittance, reflectance, band gap, extinction coefficient, urbach energy, complex dielectric constant, optical and electrical conductivity. These constants are considered to be essential in characterizing materials that are used in various applications like fabrication of optoelectronic devices. FTIR spectrum establishes the presence of various bands of functional groups expected from metal tartrate with water of crystallization.
2000-05-01
A collage of protein and virus crystals, many of which were grown on the U.S. Space Shuttle or Russian Space Station, Mir. The crystals include the proteins canavalin; mouse monoclonal antibody; a sweet protein, thaumatin; and a fungal protease. Viruses are represented here by crystals of turnip yellow mosaic virus and satellite tobacco mosaic virus. The crystals are photographed under polarized light (thus causing the colors) and range in size from a few hundred microns in edge length up to more than a millimeter. All the crystals are grown from aqueous solutions and are useful for X-ray diffraction analysis. Credit: Dr. Alex McPherson, University of California, Irvine.
Pyragas, K; Lange, F; Letz, T; Parisi, J; Kittel, A
2001-01-01
We suggest a quantitatively correct procedure for reducing the spatial degrees of freedom of the space-dependent rate equations of a multimode laser that describe the dynamics of the population inversion of the active medium and the mode intensities of the standing waves in the laser cavity. The key idea of that reduction is to take advantage of the small value of the parameter that defines the ratio between the population inversion decay rate and the cavity decay rate. We generalize the reduction procedure for the case of an intracavity frequency doubled laser. Frequency conversion performed by an optically nonlinear crystal placed inside the laser cavity may cause a pronounced instability in the laser performance, leading to chaotic oscillations of the output intensity. Based on the reduced equations, we analyze the dynamical properties of the system as well as the problem of stabilizing the steady state. The numerical analysis is performed considering the specific system of a Nd:YAG (neodymium-doped yttrium aluminum garnet) laser with an intracavity KTP (potassium titanyl phosphate) crystal.
Phase diagram of a symmetric electron-hole bilayer system: a variational Monte Carlo study.
Sharma, Rajesh O; Saini, L K; Bahuguna, Bhagwati Prasad
2018-05-10
We study the phase diagram of a symmetric electron-hole bilayer system at absolute zero temperature and in zero magnetic field within the quantum Monte Carlo approach. In particular, we conduct variational Monte Carlo simulations for various phases, i.e. the paramagnetic fluid phase, the ferromagnetic fluid phase, the anti-ferromagnetic Wigner crystal phase, the ferromagnetic Wigner crystal phase and the excitonic phase, to estimate the ground-state energy at different values of in-layer density and inter-layer spacing. Slater-Jastrow style trial wave functions, with single-particle orbitals appropriate for different phases, are used to construct the phase diagram in the (r s , d) plane by finding the relative stability of trial wave functions. At very small layer separations, we find that the fluid phases are stable, with the paramagnetic fluid phase being particularly stable at [Formula: see text] and the ferromagnetic fluid phase being particularly stable at [Formula: see text]. As the layer spacing increases, we first find that there is a phase transition from the ferromagnetic fluid phase to the ferromagnetic Wigner crystal phase when d reaches 0.4 a.u. at r s = 20, and before there is a return to the ferromagnetic fluid phase when d approaches 1 a.u. However, for r s < 20 and [Formula: see text] a.u., the excitonic phase is found to be stable. We do not find that the anti-ferromagnetic Wigner crystal is stable over the considered range of r s and d. We also find that as r s increases, the critical layer separations for Wigner crystallization increase.
NASA Astrophysics Data System (ADS)
Shruthi, C.; Ravindrachary, V.; Prasad, D. Jagadeesh; Guruswamy, B.; Hegde, Shreedatta
2017-05-01
A novel organic nonlinear optical (NLO) material (2E)-1-(2-Bromo-4,5-Dimethoxyphenyl)-3-(3-Bromo-4-Fluorophenyl)Prop-2-en-1-one has been synthesized using Claisen-Schmidth condensation method. The chemical structure of the compound was confirmed by recording its FT-IR spectrum and the functional groups were identified. Single crystals were grown by slow evaporation method and the single crystal XRD study reveals that the compound crystallizes in the monoclinic crystal system with a space group -P 2yn. The observed cell parameters are a = 9.346(5) A°, b = 12.953(7) A°, c = 14.355(8) A°, α = 90°, β = 108.379°(9), γ = 90°. UV-Visible study shows that the compound is transparent in the entire visible region and the absorption takes place in the UV range. The Non linear optical efficiency of the crystal was estimated and it is found to be 0.5 times that of standard KDP crystal.
NASA Astrophysics Data System (ADS)
Senthil, S.; Madhavan, J.
2015-02-01
In the present paper, attempts were made to grow good quality metaNitroaniline (mNA) and N-3-Nitrophenyl (3-NAA) single crystals. The lattice parameter values from the Powder X-ray diffraction pattern confirms that mNA belongs to orthorhombic crystal system with the unit cell parameter values of a = 6.501 Å, b = 19.330 Å and c = 5.082 Å with space group Pbc21. Similarly the powder XRD data indicates that 3-NAA crystal retained its monoclinic structure with lattice parameter values a = 9.762 Å, b =13.287 Å, c =13.226 Å, and β = 102.99°. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by Fourier Transform infrared spectroscopy technique. The SHG efficiency of mNA and 3NAA was determined by Kurtz and Perry powder technique. The Optical absorption study confirms the suitability of the crystals for device applications. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester.
NASA Astrophysics Data System (ADS)
Saravanan, M.; Abraham Rajasekar, S.
2016-04-01
The crystals (benzaldehyde 4-nitro phenyl hydrazone (BPH)) appropriate for NLO appliance were grown by the slow cooling method. The solubility and metastable zone width measurement of BPH specimen was studied. The material crystallizes in the monoclinic crystal system with noncentrosymmetric space group of Cc. The optical precision in the whole visible region was found to be excellent for non-linear optical claim. Excellence of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of BPH sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The dielectric studies were executed at varied temperatures and frequencies to investigate the electrical properties. Photoconductivity measurement enumerates consummate of inducing dipoles due to strong incident radiation and also divulge the nonlinear behaviour of the material. The third order nonlinear optical properties of BPH crystals were deliberate by Z-scan method.
1989-07-01
defects in crsytals. An experiment that flew on Space- lab 1 by Littke and John showed that space grown protein crystals are considerably 1. Bugg...shipyard welding situations without sigmutficant dmae in the system itself. This Mak was q esord by the Naval Sea Systms amard, xqw t of the Navy, Urer...a modified part E. The inspection station inspects a defined percentage of parts. Of those inspected, a defined percentage is defective . Of those
Microgravity: New opportunities to facilitate biotechnology development
NASA Astrophysics Data System (ADS)
Johnson, Terry; Todd, Paul; Stodieck, Louis S.
1996-03-01
New opportunities exist to use the microgravity environment to facilitate biotechnology development. BioServe Space Technologies Center for the Commercial Development of Space offers access to microgravity environments for companies who wish to perform research or develop products in three specific life-science fields: Biomedical and Pharmaceutical Research, Biotechnology and Bioprocessing Research, and Agricultural and Environmental Research. Examples of each include physiological testing of new pharmaceutical countermeasures against symptoms that are exaggerated in space flight, crystallization and testing of novel, precompetitive biopharmaceutical substances in a convection-free environment, and closed life-support system product development.
NASA Astrophysics Data System (ADS)
Feng, Zhicun; Zhang, Hang; Xu, Kangzhen; Song, Jirong; Zhao, Fengqi
2018-04-01
Six different energetic silver complexes of 2-(dinitromethylene)-1,3-diazacyclopentane (DNDZ), Ag(DNDZ) (1), [Ag2(H2O)(DNDZ)]n (2), Ag(NH3)DNDZ (3), Ag(CH3NH2)(DNDZ) (4), Ag(C2H5NH2)(DNDZ) (5) and Ag(C3H7NH2)(DNDZ) (6), were first synthesized and structurally characterized. Complexes 2, 3, 5 and 6 were characterized by the single crystal X-ray diffraction analysis. Complexes 2, 5 and 6 crystallize in the monoclinic crystal system with space group P21/n containing four molecules per unit cell, but the crystal of complex 3 is triclinic with space group P-1 containing two molecules in each unit cell. Complexes 2 and 3 possess Ag⋯Ag interaction and corresponding central symmetric structure, but complexes 5 and 6 do not. Thermal behaviors of complexes 1-6 were determined and analyzed. The order of thermal stability for the six complexes is 4 > 3 >1 > 2 >5 > 6. Impact sensitivities for complexes 1-6 are >12 J, > 4 J, > 13 J, > 16 J, > 8 J and >7 J respectively, which corresponds well to the results of thermal stability for the six complexes except for complex 2. Moreover, natural bond orbital (NBO) analysis was used to investigate the bonding and hybridization of complex 3.
NASA Technical Reports Server (NTRS)
Nielsen, Kjeld Flemming; Lind, M. David
1992-01-01
Experiment A0139A on the Long Duration Exposure Facility (LDEF) carried four large containers into orbit five years with crystal growth solutions for lead sulfide, calcium carbonate, and TTF-TCNQ. Although temperature data was lost, the experimental program had been working since the valves in all containers had been opened. All four experiments produced crystals of varying quality. The calcium carbonate crystals had the best appearance. The TTF-TCNQ crystals were packed together near the valve openings of the container. When taken apart, the single crystals showed some unusual morphological properties. X ray investigations as well as conductivity measurements on long duration space grown TTF-TCNQ crystals will be presented. Comparisons will be made with our previous space solution growth experiments. The TTF-TCNQ crystals are no longer of the highest interest, so this activity has been terminated in favor of calcium carbonate and calcium phosphate crystallizations.
NASA Astrophysics Data System (ADS)
Tian, Huiping; Shen, Guansheng; Liu, Weijia; Ji, Yuefeng
2013-07-01
An integrated model of photonic crystal (PC) demultiplexer that can be used to combine dense wavelength-division multiplexing (DWDM) and coarse wavelength-division multiplexing (CWDM) systems is first proposed. By applying the PC demultiplexer, dense channel spacing 0.8 nm and coarse channel spacing 20 nm are obtained at the same time. The transmission can be improved to nearly 90%, and the crosstalk can be decreased to less than -18 dB by enlarging the width of the bus waveguide. The total size of the device is 21×42 μm2. Four channels on one side of the demultiplexer can achieve DWDM in the wavelength range between 1575 and 1578 nm, and the other four channels on the other side can achieve CWDM in the wavelength range between 1490 and 1565 nm, respectively. The demonstrated demultiplexer can be applied in the future CWDM and DWDM system, and the architecture costs can be significantly reduced.
Crystallization of Chicken Egg-White Lysozyme from Ammonium Sulfate
NASA Technical Reports Server (NTRS)
Forsythe, Elizabeth L.; Snell, Edward H.; Pusey, Marc L.
1997-01-01
Chicken egg-white lysozyme was crystallized from ammonium sulfate over the pH range 4.0-7.8, with protein concentrations from 100 to 150 mg/ml. Crystals were obtained by vapor-diffusion or batch-crystallization methods. The protein crystallized in two morphologies with an apparent morphology dependence on temperature and protein concentration. In general, tetragonal crystals could be grown by lowering the protein concentration or temperature. Increasing the temperature or protein concentration resulted in the growth of orthorhombic crystals. Representative crystals of each morphology were selected for X-ray analysis. The tetragonal crystals belonged to the P4(sub 3)2(sub 1)2 space group with crystals grown at ph 4.4 having unit-cell dimensions of a = b = 78.7 1, c=38.6 A and diffracting to beyond 2.0 A. The orthorhombic crystals, grown at pH 4.8, were of space group P2(sub 1)2(sub 1)2 and had unit-cell dimensions of a = 30.51, b = 56.51 and c = 73.62 A.
NASA Astrophysics Data System (ADS)
Hachuła, Barbara; Jabłońska-Czapla, Magdalena; Flakus, Henryk T.; Nowak, Maria; Kusz, Joachim
2015-01-01
In the present work, the experimental and theoretical study of the nature of the inter-hydrogen bond interactions in two different carboxylic acids, 3-methylcinnamic acid (3MCA) and 4-phenylbutyric acid (4PBA), were reported. The polarized IR spectra of 3MCA and 4PBA crystals were recorded at the frequency ranges of the νOsbnd H and νOsbnd D bands. The spectral properties of 3MCA and 4PBA interpreted with the aid of the calculations based on the "strong-coupling" model. The differences in the spectral properties of the two different dimeric systems in the crystals provide a valuable information about the existence of a direct relationship between the crystal spectral properties in IR and the electronic structure of the molecular systems. In 3MCA crystals strong vibrational exciton interactions favor a "tail-to-head" (TH)-type Davydov coupling widespread via the π-electrons, whereas in 4PBA crystals a weak "through-space" (SS) exciton coupling is responsible for a "side-to-side"-type coupling. The relative contribution of each individual exciton coupling mechanism in IR spectra generation strongly depends on temperature and molecular electronic structure. The H/D isotopic recognition effect, depending on a non-random distribution of protons and deuterons in the crystal hydrogen bridges, was also analyzed.
Hachuła, Barbara; Jabłońska-Czapla, Magdalena; Flakus, Henryk T; Nowak, Maria; Kusz, Joachim
2015-01-05
In the present work, the experimental and theoretical study of the nature of the inter-hydrogen bond interactions in two different carboxylic acids, 3-methylcinnamic acid (3MCA) and 4-phenylbutyric acid (4PBA), were reported. The polarized IR spectra of 3MCA and 4PBA crystals were recorded at the frequency ranges of the νO-H and νO-D bands. The spectral properties of 3MCA and 4PBA interpreted with the aid of the calculations based on the "strong-coupling" model. The differences in the spectral properties of the two different dimeric systems in the crystals provide a valuable information about the existence of a direct relationship between the crystal spectral properties in IR and the electronic structure of the molecular systems. In 3MCA crystals strong vibrational exciton interactions favor a "tail-to-head" (TH)-type Davydov coupling widespread via the π-electrons, whereas in 4PBA crystals a weak "through-space" (SS) exciton coupling is responsible for a "side-to-side"-type coupling. The relative contribution of each individual exciton coupling mechanism in IR spectra generation strongly depends on temperature and molecular electronic structure. The H/D isotopic recognition effect, depending on a non-random distribution of protons and deuterons in the crystal hydrogen bridges, was also analyzed. Copyright © 2014 Elsevier B.V. All rights reserved.
Hempler, Daniela; Schmidt, Martin U; van de Streek, Jacco
2017-08-01
More than 600 molecular crystal structures with correct, incorrect and uncertain space-group symmetry were energy-minimized with dispersion-corrected density functional theory (DFT-D, PBE-D3). For the purpose of determining the correct space-group symmetry the required tolerance on the atomic coordinates of all non-H atoms is established to be 0.2 Å. For 98.5% of 200 molecular crystal structures published with missed symmetry, the correct space group is identified; there are no false positives. Very small, very symmetrical molecules can end up in artificially high space groups upon energy minimization, although this is easily detected through visual inspection. If the space group of a crystal structure determined from powder diffraction data is ambiguous, energy minimization with DFT-D provides a fast and reliable method to select the correct space group.
The statistical kinematical theory of X-ray diffraction as applied to reciprocal-space mapping
Nesterets; Punegov
2000-11-01
The statistical kinematical X-ray diffraction theory is developed to describe reciprocal-space maps (RSMs) from deformed crystals with defects of the structure. The general solutions for coherent and diffuse components of the scattered intensity in reciprocal space are derived. As an example, the explicit expressions for intensity distributions in the case of spherical defects and of a mosaic crystal were obtained. The theory takes into account the instrumental function of the triple-crystal diffractometer and can therefore be used for experimental data analysis.
Qin, Chao; Wang, Xin-Long; Wang, En-Bo; Su, Zhong-Min
2005-10-03
The complexes of formulas Ln(pydc)(Hpydc) (Ln = Sm (1), Eu (2), Gd (3); H2pydc = pyridine-2,5-dicarboxylic acid) and Ln(pydc)(bc)(H2O) (Ln = Sm (4), Gd (5); Hbc = benzenecarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TG analysis, and single-crystal X-ray diffraction. Compounds 1-3 are isomorphous and crystallize in the orthorhombic system, space group Pbcn. Their final three-dimensional racemic frameworks can be considered as being constructed by helix-linked scalelike sheets. Compounds 4 and 5 are isostructural and crystallize in the monoclinic system, space group P2(1)/c. pydc ligands bridge dinuclear lanthanide centers to form the three-dimensional frameworks featuring hexagonal channels along the a-axis that are occupied by one-end-coordinated bc ligands. From the topological point of view, the five three-dimensional nets are binodal with six- and three-connected nodes, the former of which exhibit a rutile-related (4.6(2))(2)(4(2).6(9).8(4)) topology that is unprecedented within coordination frames, and the latter two species display a distorted rutile (4.6(2))(2)(4(2).6(10).8(3)) topology. Furthermore, the luminescent properties of 2 were studied.
NASA Technical Reports Server (NTRS)
1977-01-01
Solar cells and optical configurations for the SSPS were examined. In this task, three specific solar cell materials were examined: single crystal silicon, single crystal gallium arsenide, and polycrystalline cadmium sulfide. The comparison of the three different cells on the basis of a subsystem parametric cost per kW of SSPS-generated power at the terrestrial utility interface showed that gallium arsenide was the most promising solar cell material at high concentration ratios. The most promising solar cell material with no concentration, was dependent upon the particular combination of parameters representing cost, mass and performance that were chosen to represent each cell in this deterministic comparative analysis. The potential for mass production, based on the projections of the present state-of-the-art would tend to favor cadmium sulfide in lieu of single crystal silicon or gallium arsenide solar cells.
Hong, Seung Kon; Kim, Kook Han; Kim, Eunice EunKyeong
2010-01-01
Malonyl-CoA:acyl-carrier protein transacylase (MCAT), encoded by the fabd gene, is a key enzyme in type II fatty-acid biosynthesis. It is responsible for transferring the malonyl group from malonyl-CoA to the holo acyl-carrier protein (ACP). Since the type II system differs from the type I system that mammals use, it has received enormous attention as a possible antibiotic target. In particular, only a single isoform of MCAT has been reported and a continuous coupled enzyme assay has been developed. MCAT from Staphylococcus aureus was overexpressed in Escherichia coli and the protein was purified and crystallized. Diffraction data were collected to 1.2 A resolution. The crystals belonged to space group P2(1), with unit-cell parameters a = 41.608, b = 86.717, c = 43.163 A, alpha = gamma = 90, beta = 106.330 degrees . The asymmetric unit contains one SaMCAT molecule.
Application of single crystal superalloys for Earth-to-orbit propulsion systems
NASA Technical Reports Server (NTRS)
Dreshfield, R. L.; Parr, R. A.
1987-01-01
Single crystal superalloys were first identified as potentially useful engineering materials for aircraft gas turbine engines in the mid-1960's. Although they were not introduced into service as turbine blades in commercial aircraft engines until the early 1980's, they have subsequently accumulated tens of millions of flight hours in revenue producing service. The space shuttle main engine (SSME) and potential advanced earth-to-orbit propulsion systems impose severe conditions on turbopump turbine blades which for some potential failure modes are more severe than in aircraft gas turbines. Research activities which are directed at evaluating the potential for single crystal superalloys for application as turbopump turbine blades in the SSME and advanced rocket engines are discussed. The mechanical properties of these alloys are summarized and the effects of hydrogen are noted. The use of high gradient directional solidification and hot isostatic pressing to improve fatigue properties is also addressed.
Spinless hourglass nodal-line semimetals
NASA Astrophysics Data System (ADS)
Takahashi, Ryo; Hirayama, Motoaki; Murakami, Shuichi
2017-10-01
Nodal-line semimetals, one of the topological semimetals, have degeneracy along nodal lines where the band gap is closed. In many cases, the nodal lines appear accidentally, and in such cases it is impossible to determine whether the nodal lines appear or not, only from the crystal symmetry and the electron filling. In this paper, for spinless systems, we show that in specific space groups at 4 N +2 fillings (8 N +4 fillings including the spin degree of freedom), presence of the nodal lines is required regardless of the details of the systems. Here, the spinless systems refer to crystals where the spin-orbit coupling is negligible and the spin degree of freedom can be omitted because of the SU(2) spin degeneracy. In this case the shape of the band structure around these nodal lines is like an hourglass, and we call this a spinless hourglass nodal-line semimetal. We construct a model Hamiltonian as an example and we show that it is always in the spinless hourglass nodal-line semimetal phase even when the model parameters are changed without changing the symmetries of the system. We also establish a list of all the centrosymmetric space groups, under which spinless systems always have hourglass nodal lines, and illustrate where the nodal lines are located. We propose that Al3FeSi2 , whose space-group symmetry is Pbcn (No. 60), is one of the nodal-line semimetals arising from this mechanism.
2001-01-24
Gaseous Nitrogen Dewar apparatus developed by Dr. Alex McPherson of the University of California, Irvine for use aboard Mir and the International Space Station allows large quantities of protein samples to be crystallized in orbit. The specimens are contained either in plastic tubing (heat-sealed at each end). Biological samples are prepared with a precipitating agent in either a batch or liquid-liquid diffusion configuration. The samples are then flash-frozen in liquid nitrogen before crystallization can start. On orbit, the Dewar is placed in a quiet area of the station and the nitrogen slowly boils off (it is taken up by the environmental control system), allowing the proteins to thaw to begin crystallization. The Dewar is returned to Earth after one to four months on orbit, depending on Shuttle flight opportunities. The tubes then are analyzed for crystal presence and quality
Crystallization and preliminary X-ray analysis of gene product 44 from bacteriophage Mu
Kondou, Youhei; Kitazawa, Daisuke; Takeda, Shigeki; Yamashita, Eiki; Mizuguchi, Mineyuki; Kawano, Keiichi; Tsukihara, Tomitake
2005-01-01
Bacteriophage Mu baseplate protein gene product 44 (gp44) is an essential protein required for the assembly of viable phages. To investigate the roles of gp44 in baseplate assembly and infection, gp44 was crystallized at pH 6.0 in the presence of 20% 2-methyl-2,4-pentanediol. The crystals belong to space group R3, with unit-cell parameters a = b = 127.47, c = 63.97 Å. The crystals diffract X-rays to at least 2.1 Å resolution and are stable in the X-ray beam and are therefore appropriate for structure determination. Native data have been collected to 2.1 Å resolution using a DIP6040 image-plate system at beamline BL44XU at the SPring-8 facility in Japan. PMID:16508104
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abosadiya, Hamza M.; Hasbullah, Siti Aishah; Yamin, Bohari M.
2015-09-25
C-4-acetamidophenylcalix[4]pyrogallolarene was synthesized by an acid catalyzed condensation reaction of pyrogallol with 4-acetamidobenzaldehyde. The compound was characterized by IR, {sup 1}H and {sup 13}C NMR spectroscopy. Single crystal X-ray analysis revealed that the molecule crystallized in a triclinic system with space group Pī and the unit cell dimensions a= 12.2948(16) Å, b= 13.4423(17) Å, c= 13.5906(18) Å, α =107.549(4)°, β =102.034(4)°, γ =90.535(4)°, Z= 1 and V= 2088.2(5) Å{sup 3}. The macrocyclic calix adopts a chair (C{sub 2h}) conformation and the molecule is associated with eight DMSO molecules of crystallization. Antioxidant test by DPPH method showed that the compound exhibitsmore » good antioxidant activity of about 72%.« less
New crystal forms of Diocleinae lectins in the presence of different dimannosides
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moreno, Frederico Bruno Mendes Batista; Bezerra, Gustavo Arruda; Oliveira, Taianá Maia de
2006-11-01
The crystallization and preliminary X-ray data of Canavalia gladiata lectin (CGL) and C. maritima lectin (CML) complexed with Man(α1-2)Man(α1)OMe, Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe in two crystal forms [the complexes with Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe crystallized in space group P3{sub 2} and those with Man(α1-2)Man(α1)OMe crystallized in space group I222], which differed from those of the native proteins (P2{sub 1}2{sub 1}2 for CML and C222 for CGL), are reported. Studying the interactions between lectins and sugars is important in order to explain the differences observed in the biological activities presented by the highly similar proteins of the Diocleinae subtribe. Here, the crystallization andmore » preliminary X-ray data of Canavalia gladiata lectin (CGL) and C. maritima lectin (CML) complexed with Man(α1-2)Man(α1)OMe, Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe in two crystal forms [the complexes with Man(α1-3)Man(α1)OMe and Man(α1-4)Man(α1)OMe crystallized in space group P3{sub 2} and those with Man(α1-2)Man(α1)OMe crystallized in space group I222], which differed from those of the native proteins (P2{sub 1}2{sub 1}2 for CML and C222 for CGL), are reported. The crystal complexes of ConA-like lectins with Man(α1-4)Man(α1)OMe are reported here for the first time.« less
Cao, Wudi; Wang, Yanting; Saielli, Giacomo
2018-01-11
We simulate the heating process of ionic liquids [C n Mim][NO 3 ] (n = 4, 6, 8, 10, 12), abbreviated as C n , by means of molecular dynamics (MD) simulation starting from a manually constructed triclinic crystal structure composed of polar layers containing anions and cationic head groups and nonpolar regions in between containing cationic alkyl side chains. During the heating process starting from 200 K, each system undergoes first a solid-solid phase transition at a lower temperature, and then a melting phase transition at a higher temperature to an isotropic liquid state (C 4 , C 6 , and C 8 ) or to a liquid crystal state (C 10 and C 12 ). After the solid-solid phase transition, all systems keep the triclinic space symmetry, but have a different set of lattice constants. C 4 has a more significant structural change in the nonpolar regions which narrows the layer spacing, while the layer spacings of other systems change little, which can be qualitatively understood by considering that the contribution of the effective van der Waals interaction in the nonpolar regions (abbreviated as EF1) to free energy becomes stronger with increasing side-chain length, and at the same time the contribution of the effective electrostatic interaction in the polar layers (abbreviated as EF2) to free energy remains almost the same. The melting phase transitions of all systems except C 6 are found to be a two-step process with an intermediate metastable state appeared during the melting from the crystal state to the liquid or liquid crystal state. Because the contribution of EF2 to the free energy is larger than EF1, the metastable state of C 4 has the feature of having higher ordered polar layers and lower ordered side-chain orientation. By contrast, C 8 -C 12 have the feature of having lower ordered polar layers and higher ordered side-chain orientation, because for these systems, the contribution of EF2 to the free energy is smaller than EF1. No metastable state is found for C 6 because the free-energy contribution of EF1 is balanced with EF2.
NASA Astrophysics Data System (ADS)
Alfi, Nafiseh; Khorasani-Motlagh, Mozhgan; Rezvani, Ali Reza; Noroozifar, Meissam; Molčanov, Krešimir
2017-06-01
A heteroleptic europium coordination compound formulated as [Eu(phen)2(OH2)2(Cl)2](Cl)(H2O) (phen = 1,10-phenanthroline), has been synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffractometer. Crystal structure analysis reveals the complex is crystallized in orthorhombic system with Pca21 space group. Electronic absorption and various emission methods for investigation of the binding system of europium(III) complex to Fish Salmon deoxyribonucleic acid (FS-DNA) and Bovamin Serum Albumin (BSA) have been explored. Furthermore, the binding constants, binding sites and the corresponding thermodynamic parameters of the interaction system based on the van't Hoff equation for FS-DNA and BSA were calculated. The thermodynamic parameters reflect the exothermic nature of emission process (ΔH°<0 and ΔS°<0). The experimental results seem to indicate that the [Eu(phen)2(OH2)2(Cl)2](Cl)(H2O) bound to FS-DNA by non-intercalative mode which the groove binding is preferable mode. Also, the complex exhibits a brilliant antimicrobial activity in vitro against standard bacterial strains.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Troffer-Charlier, Nathalie; Cura, Vincent; Hassenboehler, Pierre
2007-04-01
Isolated modules of mouse coactivator-associated arginine methyltransferase 1 encompassing the protein arginine N-methyltransferase catalytic domain have been overexpressed, purified and crystallized. X-ray diffraction data have been collected and have enabled determination of the structures by multiple isomorphous replacement using anomalous scattering. Coactivator-associated arginine methyltransferase 1 (CARM1) plays a crucial role in gene expression as a coactivator of several nuclear hormone receptors and also of non-nuclear receptor systems. Its recruitment by the transcriptional machinery induces protein methylation, leading to chromatin remodelling and gene activation. CARM1{sub 28–507} and two structural states of CARM1{sub 140–480} were expressed, purified and crystallized. Crystals of CARM1{submore » 28–507} belong to space group P6{sub 2}22, with unit-cell parameters a = b = 136.0, c = 125.3 Å; they diffract to beyond 2.5 Å resolution using synchrotron radiation and contain one monomer in the asymmetric unit. The structure of CARM1{sub 28–507} was solved by multiple isomorphous replacement and anomalous scattering methods. Crystals of apo CARM1{sub 140–480} belong to space group I222, with unit-cell parameters a = 74.6, b = 99.0, c = 207.4 Å; they diffract to beyond 2.7 Å resolution and contain two monomers in the asymmetric unit. Crystals of CARM1{sub 140–480} in complex with S-adenosyl-l-homocysteine belong to space P2{sub 1}2{sub 1}2, with unit-cell parameters a = 74.6, b = 98.65, c = 206.08 Å; they diffract to beyond 2.6 Å resolution and contain four monomers in the asymmetric unit. The structures of apo and holo CARM1{sub 140–480} were solved by molecular-replacement techniques from the structure of CARM1{sub 28–507}.« less
Suguna, S; Anbuselvi, D; Jayaraman, D; Nagaraja, K S; Jeyaraj, B
2014-11-11
Piperazine-1,4-diium bis 2,4,6-trinitrophenolate is one of the useful organic materials with nonlinear optical (NLO) and pharmaceutical applications. The material was grown by slow evaporation solution growth method at room temperature. The crystal system and lattice parameters were identified by single crystal XRD analysis. The grown material crystallizes in monoclinic system with P21/n space group. The main functional groups NH2, NO2, CN, CC, and phenolic 'O' atom were identified using FTIR analysis. The protons and carbons of grown crystal with various chemical environments were studied by 1H and 13C NMR spectroscopy to confirm the molecular structure. The optical properties of the crystal were studied by UV-vis-NIR spectroscopy and the transmission 100% range starts from 532 nm onwards. The optical band gap was measured as 2.63 eV from the plot of (αhν)2 versus hν. The thermal stability was detected at 304.1°C using TG-DTA analysis. The dielectric studies of the sample were carried out at different temperatures in the frequency range from 50 Hz to 5 MHz to establish the dielectric nature of the crystal. Photoconductivity measurements were carried out on the grown crystal. The Second Harmonic Generation (SHG) of the crystal was tested to confirm the nonlinear optical property. Copyright © 2014 Elsevier B.V. All rights reserved.
MSFC (TES) Thermal Enclosure System
NASA Technical Reports Server (NTRS)
1993-01-01
The Thermal Enclosure System (TES) provides thermal control for protein crystal growth experiments. The TES, housed in two middeck lockers on board the Space Shuttle, contains four Vapor Diffusion Apparatus (VDA) trays. Each can act as either a refrigerator or an incubator and its temperature can be controlled to within one-tenth degree C. The first flight of the TES was during USMP-2 (STS-62).
Decades of Data: Extracting Trends from Microgravity Crystallization History
NASA Technical Reports Server (NTRS)
Judge, R. A.; Snell, E. H.; Kephart, R.; vanderWoerd, M.
2004-01-01
The reduced acceleration environment of an orbiting spacecraft has been proposed as an ideal environment for biological crystal growth as the first sounding rocket flight in 1981 many crystallization experiments have flown with some showing improvement and others not. To further explore macromolecule crystal improvement in microgravity we have accumulated data from published reports and reports submitted by 63 missions including the Space Shuttle program, unmanned satellites, the Russian Space Station MIR and sounding rocket experiments. While it is not at this point in time a comprehensive record of all flight crystallization experimental results, there is however sufficient information for emerging trends to be identified. In this study the effects of the acceleration environment, the techniques of crystallization, sample molecular weight and the response of individual macromolecules to microgravity crystallization will be investigated.
Seo, Kyung Hye; Supangat; Kim, Hye Lim; Park, Young Shik; Jeon, Che Ok; Lee, Kon Ho
2008-02-01
6-Pyruvoyltetrahydropterin synthase from E. coli (ePTPS) has been crystallized using the hanging-drop vapour-diffusion method. Hexagonal- and rectangular-shaped crystals were obtained. Diffraction data were collected from the hexagonal and rectangular crystals to 3.0 and 2.3 A resolution, respectively. The hexagonal plate-shaped crystals belonged to space group P321, with unit-cell parameters a = b = 112.59, c = 68.82 A , and contained two molecules in the asymmetric unit. The rectangular crystals belonged to space group I222, with unit-cell parameters a = 112.76, b = 117.66, c = 153.57 A , and contained six molecules in the asymmetric unit. The structure of ePTPS in both crystal forms has been determined by molecular replacement.
Seo, Kyung Hye; Supangat; Kim, Hye Lim; Park, Young Shik; Jeon, Che Ok; Lee, Kon Ho
2008-01-01
6-Pyruvoyltetrahydropterin synthase from E. coli (ePTPS) has been crystallized using the hanging-drop vapour-diffusion method. Hexagonal- and rectangular-shaped crystals were obtained. Diffraction data were collected from the hexagonal and rectangular crystals to 3.0 and 2.3 Å resolution, respectively. The hexagonal plate-shaped crystals belonged to space group P321, with unit-cell parameters a = b = 112.59, c = 68.82 Å, and contained two molecules in the asymmetric unit. The rectangular crystals belonged to space group I222, with unit-cell parameters a = 112.76, b = 117.66, c = 153.57 Å, and contained six molecules in the asymmetric unit. The structure of ePTPS in both crystal forms has been determined by molecular replacement. PMID:18271114
The crystalline revolution :ISO's finding opens a new research field, "astro-mineralogy"
NASA Astrophysics Data System (ADS)
2000-02-01
Silicate minerals were known to be a main component of dust in space, but detecting them in a crystallised state has been a surprise. It allows the identification of precise silicates in astronomical objects, which will open "a totally new field in astronomy: astro-mineralogy. This is the crystalline revolution", said the author, Dutch astronomer Rens Waters of Amsterdam university. "It's really fantastic, this possibility of identifying the silicates. Before ISO everybody thought that all silicates in space were amorphous, without a well-ordered internal structure; that means you cannot differentiate among the many different silicates existing. Now we can try to identify them and track their presence in different regions. A whole new research field is starting", said Rens Waters, who brought to the press conference samples of several terrestrial crystalline silicates: olivine and pyroxene, the most common silicates on Earth. Crystals give key clues about the physical conditions and evolutionary history of crystal-bearing objects. The precise mechanisms for crystal-making are now being researched now very actively in the laboratories, although some working-hypotheses are already being used. For instance, crystals can be made by heating the material to temperatures above 1 300 degrees Centigrade and then cooling it down slowly. Those found so far by ISO are at -170 degrees Centigrade, both in stellar envelopes and in protoplanetary discs. In the case of the old stars -red giant stars, where crystals are found to account for as much as 20% of all the surrounding dust, astronomers think that that the high temperatures near the star triggered the crystallisation of the silicates. In the protoplanetary discs some experts postulate that electric shocks - like lightning flashes - heated the dust, which cooled afterwards. "The crystals detected by ISO in these discs have a size of about a thousandth of a millimetre. They collide with each other, forming bigger and bigger bodies. Models predict that in about ten to one hundred million years they will make planets", Waters says. "In fact, crystalline silicates are very common in our own Solar System. You also have them in the comet Hale Bopp!". The reason why crystalline silicates had not been detected before in stars has to do with their low temperatures. Cold material emits mostly infrared light, which means an infrared space telescope like ESA's ISO was needed. The two high-resolution spectrometers on-board the satellite, able to detect the 'chemical fingerprint' of the crystals, did the rest. Astronomers are sure about the discovery because those chemical fingerprints, the spectra, can be compared in laboratories with spectra from crystalline silicates found on Earth. This method has demonstrated the crystalline structure and has even already allowed the identification of some of the crystals, such as forsterite and enstatite. However, crystalline silicates are a large family and their chemical signatures can be very similar; to enlarge the list of precise crystals more work will be needed, say experts in space chemistry. That is just one of the open questions requiring lab work. There's at least another one: crystalline silicates are found around old stars, in protoplanetary disks and in our own Solar System, but not in the space among the stars; astronomers can't explain it yet. "Crystalline silicates are synthesised around the stars; then that dust goes into the interstellar space, and enriches the raw material out of which more stars and planets will form. So you would expect crystals also to be in the interstellar medium! Crystals will certainly make us learn a lot...", says Waters. "This finding shows that ISO is really unveiling the chemistry of the Universe", says ESA astronomer Alberto Salama, chairman of the workshop about ISO results in spectroscopy held this week at ESA's Villafranca station in Madrid where the results were presented to the scientific community. "This is becoming more and more a 'hot field' of research. Initially we intended to organise a modest workshop, but we have had 150 astronomers coming from all over Europe!".
Cryogenic Behavior of the High Temperature Crystal Oscillator PX-570
NASA Technical Reports Server (NTRS)
Patterson, Richard; Hammoud, Ahmad; Scherer, Steven
2011-01-01
Microprocessors, data-acquisition systems, and electronic controllers usually require timing signals for proper and accurate operation. These signals are, in most cases, provided by circuits that utilize crystal oscillators due to availability, cost, ease of operation, and accuracy. Stability of these oscillators, i.e. crystal characteristics, is usually governed, amongst other things, by the ambient temperature. Operation of these devices under extreme temperatures requires, therefore, the implementation of some temperature-compensation mechanism either through the manufacturing process of the oscillator part or in the design of the circuit to maintain stability as well as accuracy. NASA future missions into deep space and planetary exploration necessitate operation of electronic instruments and systems in environments where extreme temperatures along with wide-range thermal swings are countered. Most of the commercial devices are very limited in terms of their specified operational temperature while very few custom-made and military-grade parts have the ability to operate in a slightly wider range of temperature. Thus, it is becomes mandatory to design and develop circuits that are capable of operation efficiently and reliably under the space harsh conditions. This report presents the results obtained on the evaluation of a new (COTS) commercial-off-the-shelf crystal oscillator under extreme temperatures. The device selected for evaluation comprised of a 10 MHz, PX-570-series crystal oscillator. This type of device was recently introduced by Vectron International and is designed as high temperature oscillator [1]. These parts are fabricated using proprietary manufacturing processes designed specifically for high temperature and harsh environment applications [1]. The oscillators have a wide continuous operating temperature range; making them ideal for use in military and aerospace industry, industrial process control, geophysical fields, avionics, and engine control. They exhibit low jitter and phase noise, consume little power, and are suited for high shock and vibration applications. The unique package design of these crystal oscillators offers a small ceramic package footprint, as well as providing both through-hole mounting and surface mount options.
Nirosha, M; Kalainathan, S; Sarveswari, S; Vijayakumar, V
2014-04-05
A single crystal of 3-acetyl-2-methyl-4-phenylquinolin-1-ium chloride has grown by slow evaporation solution growth technique using ethanol as solvent. The structural, thermal, optical and mechanical property has studied for the grown crystal. Single crystal XRD revealed that the crystal belongs to monoclinic system with space group P21/c. The presences of Functional groups in the crystallized material have confirmed using the FTIR vibrational spectrum. The optical absorbance spectrum recorded from 190 to 1100nm shows the cut-off wavelength occurs at 371nm. The material shows its transparency in the entire region of the visible spectrum. The photoluminescence spectrum shows the ultraviolet and blue emission in the crystal. Thermogravimetric and differential thermal analysis reveal the thermal stability of the grown crystal. Etching study shows the grown mechanism and surface features of the crystal. Vickers microhardness studies have carried out on the (01-1) plane to understand the mechanical properties of the grown crystal. The hardness of the title compound increases on increasing the load. The Meyer's index number (n), and the stiffness constants for different loads has calculated and reported. Copyright © 2013 Elsevier B.V. All rights reserved.
Disordered crystals from first principles I: Quantifying the configuration space
NASA Astrophysics Data System (ADS)
Kühne, Thomas D.; Prodan, Emil
2018-04-01
This work represents the first chapter of a project on the foundations of first-principle calculations of the electron transport in crystals at finite temperatures. We are interested in the range of temperatures, where most electronic components operate, that is, room temperature and above. The aim is a predictive first-principle formalism that combines ab-initio molecular dynamics and a finite-temperature Kubo-formula for homogeneous thermodynamic phases. The input for this formula is the ergodic dynamical system (Ω , G , dP) defining the thermodynamic crystalline phase, where Ω is the configuration space for the atomic degrees of freedom, G is the space group acting on Ω and dP is the ergodic Gibbs measure relative to the G-action. The present work develops an algorithmic method for quantifying (Ω , G , dP) from first principles. Using the silicon crystal as a working example, we find the Gibbs measure to be extremely well characterized by a multivariate normal distribution, which can be quantified using a small number of parameters. The latter are computed at various temperatures and communicated in the form of a table. Using this table, one can generate large and accurate thermally-disordered atomic configurations to serve, for example, as input for subsequent simulations of the electronic degrees of freedom.
G-Jitter Effects in Protein Crystal Growth - A Numerical Study
NASA Technical Reports Server (NTRS)
Ramachandran, N.; Baugher, C. R.
1995-01-01
The impact of spacecraft acceleration environment on Protein Crystal Growth (PCG) is studied. A brief overview of the Space Shuttle acceleration environment is provided followed by a simple scaling procedure used to obtain estimates of the flow and concentration field characteristics in PCG. A detailed two-dimensional numerical model is then used to simulate the PCG system response to different disturbance scenarios; viz. residual g effects, impulse type disturbances and oscillatory inputs. The results show that PCG is susceptible to g-jitter and is a good candidate for vibration isolation.
Tris(acetonitrile)chloropalladium tetrafluoroborate synthesis, application and structural analysis
NASA Astrophysics Data System (ADS)
Dybała, Izabela; Demchuk, Oleg M.
2016-10-01
Results of the single crystal X-ray diffraction analysis of tris(acetonitrile)chloropalladium tetrafluoroborate [PdCl(CH3CN)3]BF4 are presented in details. It was found that the title compound crystallises in the monoclinic system, in the space group C2/c. The role of charge-assisted C-HṡṡṡF-B interactions in crystal architecture was investigated. Due to its untypical properties the prepared [PdCl(CH3CN)3]BF4 has proved to be an excellent palladium source in the synthesis of phosphine-palladium complexes.
Mapping of spin wave propagation in a one-dimensional magnonic crystal
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ordóñez-Romero, César L., E-mail: cloro@fisica.unam.mx; Lazcano-Ortiz, Zorayda; Aguilar-Huerta, Melisa
2016-07-28
The formation and evolution of spin wave band gaps in the transmission spectrum of a magnonic crystal have been studied. A time and space resolved magneto inductive probing system has been used to map the spin wave propagation and evolution in a geometrically structured yttrium iron garnet film. Experiments have been carried out using (1) a chemically etched magnonic crystal supporting the propagation of magnetostatic surface spin waves, (2) a short microwave pulsed excitation of the spin waves, and (3) direct spin wave detection using a movable magneto inductive probe connected to a synchronized fast oscilloscope. The results show thatmore » the periodic structure not only modifies the spectra of the transmitted spin waves but also influences the distribution of the spin wave energy inside the magnonic crystal as a function of the position and the transmitted frequency. These results comprise an experimental confirmation of Bloch′s theorem in a spin wave system and demonstrate good agreement with theoretical observations in analogue phononic and photonic systems. Theoretical prediction of the structured transmission spectra is achieved using a simple model based on microwave transmission lines theory. Here, a spin wave system illustrates in detail the evolution of a much more general physical concept: the band gap.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ferralis, N.; Diehl, R.D.; Pussi, K.
2004-12-15
Potassium adsorption on graphite has been a model system for the understanding of the interaction of alkali metals with surfaces. The geometries of the (2x2) structure of potassium on both single-crystal graphite (SCG) and highly oriented pyrolytic graphite (HOPG) were investigated for various preparation conditions for graphite temperatures between 55 and 140 K. In all cases, the geometry was found to consist of K atoms in the hollow sites on top of the surface. The K-graphite average perpendicular spacing is 2.79{+-}0.03 A , corresponding to an average C-K distance of 3.13{+-}0.03 A , and the spacing between graphite planes ismore » consistent with the bulk spacing of 3.35 A. No evidence was observed for a sublayer of potassium. The results of dynamical LEED studies for the clean SCG and HOPG surfaces indicate that the surface structures of both are consistent with the truncated bulk structure of graphite.« less
NASA Astrophysics Data System (ADS)
Shakila, K.; Kalainathan, S.
2015-01-01
In this paper, we report the successful growth of complex compound of zinc iodide with thiocarbamide by slow evaporation method. The single crystal XRD study reveals that the crystal belongs to monoclinic system with centrosymmetric space group and powder XRD analysis shows that the perfect crystalline nature of the crystal. The presence of functional group and element were confirmed from FT-IR and EDAX analysis. Optical absorbance of the grown crystal was studied by UV-Vis spectrophotometer. The optical constants were calculated from the optical absorbance data such as refractive index (n), extinction coefficient (K) and reflectance (R). The optical band gap (Eg) of thiocarbamide zinc iodide crystal is 4.22 eV. The magnetic properties of grown crystal have been determined by Vibrating Sample Magnetometry (VSM). Room temperature magnetization revealed a ferromagnetic behaviour for the grown crystal. The antibacterial and antifungal activities of the title compound were performed by well diffusion method and MIC method against the standard bacteria like Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and against fungus like Aspergillus niger, Rhizopus sps and Penicillium sps. Thermal behaviour of the crystal has been investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA).
NASA Astrophysics Data System (ADS)
Saravanan, M.
2016-08-01
The crystals (dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol [DMAPNP] suitable for NLO applications were grown by the slow cooling method. The solubility and metastable zone width measurement of DMAPNP specimen was studied. The material crystallizes in the orthorhombic crystal system with noncentrosymmetric space group of P212121. The ocular precision in the intact visible region was found to be good for non-linear optical claim. Quality of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of DMAPNP sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The third order nonlinear optical properties of DMAPNP crystals were premeditated by Z-scan method. Birefringence and optical homogeneity of the crystal were evaluated using modified channel spectrum method. The half wave voltage of the grown crystal deliberate from the elector optic experimentation. Photoconductivity measurement specified consummate of inducing dipoles owing to brawny incident radiation and also disclose the nonlinear activities of the grown specimen.
NASA Astrophysics Data System (ADS)
Theras, J. Elberin Mary; Kalaivani, D.; Jayaraman, D.; Joseph, V.
2015-10-01
L-threonine phthalate (LTP) single crystal has been grown using a solution growth technique at room temperature. Single crystal X-ray diffraction analysis reveals that LTP crystallizes in monoclinic crystal system with space group C2/c. The optical absorption studies show that the crystal is transparent in the entire visible region with a cut-off wavelength 309 nm. The optical band gap is found to be 4.05 eV. The functional groups of the synthesized compound have been identified by FTIR spectral analysis. The functional groups present in the material were also confirmed by FT-RAMAN spectroscopy. Surface morphology and the presence of various elements were studied by SEM-EDAX analysis. The thermal stability of LTP single crystal has been analyzed by TGA/DTA studies. The thermodynamic parameters such as activation energy, entropy, enthalpy and Gibbs free energy were determined for the grown material using TG data and Coats-Redfern relation. Since the grown crystal is centrosymmetric, Z-Scan studies were carried out for analyzing the third order nonlinear optical property. The nonlinear absorption coefficient, nonlinear refractive index and susceptibility have been measured using Z-Scan technique.
NASA Astrophysics Data System (ADS)
Choi, Byung Sang
Compared to overwhelming technical data available in other advanced technologies, knowledge about particle technology, especially in particle synthesis from a solution, is still poor due to the lack of available equipment to study crystallization phenomena in a crystallizer. Recent technical advances in particle size measurement such as Coulter counter and laser light scattering have made in/ex situ study of some of particle synthesis, i.e., growth, attrition, and aggregation, possible with simple systems. Even with these advancements in measurement technology, to grasp fully the crystallization phenomena requires further theoretical and technical advances in understanding such particle synthesis mechanisms. Therefore, it is the motive of this work to establish the general processing parameters and to produce rigorous experimental data with reliable performance and characterization that rigorously account for the crystallization phenomena of nucleation, growth, aggregation, and breakage including their variations with time and space in a controlled continuous mixed-suspension mixed-product removal (CMSMPR) crystallizer. This dissertation reports the results and achievements in the following areas: (1) experimental programs to support the development and validation of the phenomenological models and generation of laboratory data for the purpose of testing, refining, and validating the crystallization process, (2) development of laboratory well-mixed crystallizer system and experimental protocols to generate crystal size distribution (CSD) data, (3) the effects of feed solution concentration, crystallization temperature, feed flow rate, and mixing speed, as well as different types of mixers resulting in the evolution of CSDs with time from a concentrated brine solution, (4) with statistically designed experiments the effects of processing variables on the resultant particle structure and CSD at steady state were quantified and related to each of those operating conditions by studying the detailed crystallization processes, such as nucleation, growth, and breakage, as well as agglomeration. The purification of CaCl2 solution involving the crystallization of NaCl from the solution mixture of CaCl2, KCl, and NaCl as shipped from Dow Chemical, Ludington, in a CMSMPR crystallizer was studied as our model system because of its nucleation and crystal growth tendencies with less agglomeration. This project also generated a significant body of experimental data that are available at URL that is http://www.che.utah.edu/˜ring/CrystallizationWeb.
1999-04-21
University of Alabama engineer Stacey Giles briefs NASA astronaut Dr. Bornie Dunbar about the design and capabilities of the X-ray Crystallography Facility under development at the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, AL, April 21, 1999. The X-ray Crystallography Facility is designed to speed the collection of protein structure information from crystals grown aboard the International Space Station. By measuring and mapping the protein crystal structure in space, researchers will avoid exposing the delicate crystals to the rigors of space travel and make important research data available to scientists much faster. The X-ray Crystallography facility is being designed and developed by the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, a NASA Commercial Space Center.
1999-04-21
University of Alabama engineer Lance Weiss briefs NASA astronaut Dr. Bornie Dunbar about the design and capabilities of the X-ray Crystallography Facility under development at the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, AL, April 21, 1999. The X-ray Crystallography Facility is designed to speed the collection of protein structure information from crystals grown aboard the International Space Station. By measuring and mapping the protein crystal structure in space, researchers will avoid exposing the delicate crystals to the rigors of space travel and make important research data available to scientists much faster. The X-ray Crystallography facility is being designed and developed by the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, a NASA Commercial Space Center.
Gavrilenko, Konstantin S; Cador, Olivier; Bernot, Kevin; Rosa, Patrick; Sessoli, Roberta; Golhen, Stéphane; Pavlishchuk, Vitaly V; Ouahab, Lahcène
2008-01-01
Homo- and heterometallic 1D coordination polymers of transition metals (Co II, Mn II, Zn II) have been synthesized by an in-situ ligand generation route. Carboxylato-based complexes [Co(PhCOO)2]n (1 a, 1 b), [Co(p-MePhCOO)2]n (2), [ZnMn(PhCOO)4]n (3), and [CoZn(PhCOO)4]n (4) (PhCOOH=benzoic acid, p-MePhCOOH=p-methylbenzoic acid) have been characterized by chemical analysis, single-crystal X-ray diffraction, and magnetization measurements. The new complexes 2 and 3 crystallize in orthorhombic space groups Pnab and Pcab respectively. Their crystal structures consist of zigzag chains, with alternating M(II) centers in octahedral and tetrahedral positions, which are similar to those of 1 a and 1 b. Compound 4 crystallizes in monoclinic space group P2 1/c and comprises zigzag chains of M II ions in a tetrahedral coordination environment. Magnetic investigations reveal the existence of antiferromagnetic interactions between magnetic centers in the heterometallic complexes 3 and 4, while ferromagnetic interactions operate in homometallic compounds (1 a, 1 b, and 2). Compound 1 b orders ferromagnetically at TC=3.7 K whereas 1 a does not show any magnetic ordering down to 330 mK and displays typical single-chain magnet (SCM) behavior with slowing down of magnetization relaxation below 0.6 K. Single-crystal measurements reveal that the system is easily magnetized in the chain direction for 1 a whereas the chain direction coincides with the hard magnetic axis in 1 b. Despite important similarities, small differences in the molecular and crystal structures of these two compounds lead to this dramatic change in properties.
NASA Technical Reports Server (NTRS)
1992-01-01
An ingestible mini-thermometer capable of measuring and relaying internal body temperatures is marketed by Human Technologies, Inc. The CorTemp system, developed by Goddard Space Flight Center and Applied Physics Lab, incorporates space technologies, among them telemetry and microminiaturized circuit, sensor and battery technologies. The capsule is ingested and continually monitors temperature with a vibrating quartz crystal sensor, which telemeters signals to a recorder, where data is displayed and stored. The system is very accurate, and because it does not require wires, allows patients to be monitored in everyday situations. The industrial variant (CSC-100) has wide utility in commercial applications.
The 2002 NASA Faculty Fellowship Program Research Reports
NASA Technical Reports Server (NTRS)
Bland, J. (Compiler)
2003-01-01
Contents include the following: System Identification of X-33. Neural Network Advanced Ceramic Technology for Space Applications at NASA MSFC. Developing a MATLAB-Based Tool for Visualization and Transformation. Subsurface Stress Fields in Single Crystal (Anisotropic). Contacts Our Space Future: A Challenge to the Conceptual Artist Concept Art for Presentation and Education. Identification and Characterization of Extremophile Microorganisms. Significant to Astrobiology. Mathematical Investigation of Gamma Ray and Neutron. Absorption Grid Patterns for Homeland Defense-Related Fourier Imaging Systems. The Potential of Microwave Radiation for Processing Martian Soil. Fuzzy Logic Trajectory Design and Guidance for Terminal Area.
Survey view of EXPRESS Rack 4 in the JPM during Expedition 22
2009-12-30
iss022e015852 (12/30/2009) --- The image shows a front view of EXpedite the PRocessing of Experiments to Space Station EXPRESS Rack 4 (Rack 4,JPM/1F5) in the Japanese Experiment Module (JEM) Japanese Pressurized Module (JPM). Equipment visible in the EXPRESS Rack includes the Biotechnology Specimen Temperature Controller (BSTC) and the Gas Supply Module (GSM) support hardware for the CBOSS (Cellular Biotechnology Operations Support Systems) investigations, and the Device for the Study of Critical Liquids and Crystallization (DECLIC). Also visible is the Space Acceleration Measurement System (SAMS) II.
Lee, Sangwoo; Leighton, Chris; Bates, Frank S.
2014-11-05
Frank–Kasper phases are tetrahedrally packed structures occurring in numerous materials, from elements to intermetallics to self-assembled soft materials. They exhibit complex manifolds of Wigner–Seitz cells with many-faceted polyhedra, forming an important bridge between the simple close-packed periodic and quasiperiodic crystals. The recent discovery of the Frank–Kasper σ-phase in diblock and tetrablock polymers stimulated the experiments reported here on a poly(isoprene- b-lactide) diblock copolymer melt. Thus, analysis of small-angle X-ray scattering and mechanical spectroscopy exposes an undiscovered competition between the tendency to form self-assembled particles with spherical symmetry, and the necessity to fill space at uniform density within the framework imposedmore » by the lattice. We thus deduce surprising analogies between the symmetry breaking at the body-centered cubic phase to σ-phase transition in diblock copolymers, mediated by exchange of mass, and the symmetry breaking in certain metals and alloys (such as the elements Mn and U), mediated by exchange of charge. Similar connections are made between the role of sphericity in real space for polymer systems, and the role of sphericity in reciprocal space for metallic systems such as intermetallic compounds and alloys. These findings establish new links between disparate materials classes, provide opportunities to improve the understanding of complex crystallization by building on synergies between hard and soft matter, and, perhaps most significantly, challenge the view that the symmetry breaking required to form reduced symmetry structures (possibly even quasiperiodic crystals) requires particles with multiple predetermined shapes and/or sizes.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Sangwoo; Leighton, Chris; Bates, Frank S.
Frank–Kasper phases are tetrahedrally packed structures occurring in numerous materials, from elements to intermetallics to self-assembled soft materials. They exhibit complex manifolds of Wigner–Seitz cells with many-faceted polyhedra, forming an important bridge between the simple close-packed periodic and quasiperiodic crystals. The recent discovery of the Frank–Kasper σ-phase in diblock and tetrablock polymers stimulated the experiments reported here on a poly(isoprene- b-lactide) diblock copolymer melt. Thus, analysis of small-angle X-ray scattering and mechanical spectroscopy exposes an undiscovered competition between the tendency to form self-assembled particles with spherical symmetry, and the necessity to fill space at uniform density within the framework imposedmore » by the lattice. We thus deduce surprising analogies between the symmetry breaking at the body-centered cubic phase to σ-phase transition in diblock copolymers, mediated by exchange of mass, and the symmetry breaking in certain metals and alloys (such as the elements Mn and U), mediated by exchange of charge. Similar connections are made between the role of sphericity in real space for polymer systems, and the role of sphericity in reciprocal space for metallic systems such as intermetallic compounds and alloys. These findings establish new links between disparate materials classes, provide opportunities to improve the understanding of complex crystallization by building on synergies between hard and soft matter, and, perhaps most significantly, challenge the view that the symmetry breaking required to form reduced symmetry structures (possibly even quasiperiodic crystals) requires particles with multiple predetermined shapes and/or sizes.« less
Paul, A.; Mishra, A.; Surolia, A.; Vijayan, M.
2013-01-01
The last enzyme in the arginine-biosynthesis pathway, argininosuccinate lyase, from Mycobacterium tuberculosis has been cloned, expressed, purified and crystallized, and preliminary X-ray studies have been carried out on the crystals. The His-tagged tetrameric enzyme with a subunit molecular weight of 50.9 kDa crystallized with two tetramers in the asymmetric unit of the orthorhombic unit cell, space group P212121. Molecular-replacement calculations and self-rotation calculations confirmed the space group and the tetrameric nature of the molecule. PMID:24316845
Deane, Janet E.; Cordes, Frank S.; Roversi, Pietro; Johnson, Steven; Kenjale, Roma; Picking, William D.; Picking, Wendy L.; Lea, Susan M.; Blocker, Ariel
2006-01-01
A monodisperse truncation mutant of MxiH, the subunit of the needle from the Shigella flexneri type III secretion system (TTSS), has been overexpressed and purified. Crystals were grown of native and selenomethionine-labelled MxiHCΔ5 and diffraction data were collected to 1.9 Å resolution. The crystals belong to space group C2, with unit-cell parameters a = 183.4, b = 28.1, c = 27.8 Å, β = 96.5°. An anomalous difference Patterson map calculated with the data from the SeMet-labelled crystals revealed a single peak on the Harker section v = 0. Inspection of a uranyl derivative also revealed one peak in the isomorphous difference Patterson map on the Harker section v = 0. Analysis of the self-rotation function indicates the presence of a twofold non-crystallographic symmetry axis approximately along a. The calculated Matthews coefficient is 1.9 Å3 Da−1 for two molecules per asymmetric unit, corresponding to a solvent content of 33%. PMID:16511329
Deane, Janet E; Cordes, Frank S; Roversi, Pietro; Johnson, Steven; Kenjale, Roma; Picking, William D; Picking, Wendy L; Lea, Susan M; Blocker, Ariel
2006-03-01
A monodisperse truncation mutant of MxiH, the subunit of the needle from the Shigella flexneri type III secretion system (TTSS), has been overexpressed and purified. Crystals were grown of native and selenomethionine-labelled MxiH(CDelta5) and diffraction data were collected to 1.9 A resolution. The crystals belong to space group C2, with unit-cell parameters a = 183.4, b = 28.1, c = 27.8 A, beta = 96.5 degrees. An anomalous difference Patterson map calculated with the data from the SeMet-labelled crystals revealed a single peak on the Harker section v = 0. Inspection of a uranyl derivative also revealed one peak in the isomorphous difference Patterson map on the Harker section v = 0. Analysis of the self-rotation function indicates the presence of a twofold non-crystallographic symmetry axis approximately along a. The calculated Matthews coefficient is 1.9 A3 Da(-1) for two molecules per asymmetric unit, corresponding to a solvent content of 33%.
Electrohydrodynamic Flows in Electrochemical Systems
NASA Technical Reports Server (NTRS)
Saville, D. A.
2005-01-01
Recent studies have established a new class of assembly processes with colloidal suspensions. Particles are driven together to form large crystalline structures in both dc and ac fields. The current work centers on this new class of flows in ac fields. In the research carried out under the current award, it was established that: (i) Small colloidal particles crystallize near an electrode due to electrohydrodynamic flows induced by an sinusoidally varying applied potential. (ii) These flows originate due to disturbances in the electrode polarization layer arising from the presence of the particles. Inasmuch as the charge and the field strength both scale on the applied field, the flows are proportional to the square of the applied voltage. (iii) Suspensions of two different sorts of particles can be crystallized and will form well-ordered binary crystals. (iv) At high frequencies the EHD flows die out. Thus, with a homogeneous system the particles become widely spaced due to dipolar repulsion. With a binary suspension, however, the particles may become attractive due to dipolar attraction arising from differences in electrokinetic dipoles. Consequently binary crystals form at both high and low frequencies.
The growth of materials processing in space - A history of government support for new technology
NASA Technical Reports Server (NTRS)
Mckannan, E. C.
1983-01-01
Development of a given technology for national defense and large systems developments when the task is too large or risky for entrepreneurs, yet is clearly in the best interest of the nation are discussed. Advanced research to identify areas of interest was completed. Examples of commercial opportunities are the McDonnell-Douglas Corporation purification process for pharmaceutical products and the Microgravity Research Associates process for growing gallium arsenide crystals in space.
Materials processing in space: Future technology trends
NASA Technical Reports Server (NTRS)
Barter, N. J.
1980-01-01
NASA's materials processing in space- (MPS) program involves both ground and space-based research and looks to frequent and cost effective access to the space environment for necessary progress. The first generation payloads for research are under active design and development. They will be hosted by the Space Shuttle/Spacelab on Earth orbital flights in the early 1980's. hese missions will focus on the acquisition of materials behavior research data, the potential enhancement of Earth based technology, and the implementation of space based processing for specialized, high value materials. Some materials to be studied in these payloads may provide future breakthroughs for stronger alloys, ultrapure glasses, superior electronic components, and new or better chemicals. An operational 25 kW power system is expected to be operational to support sustained, systematic space processing activity beyond shuttle capability for second generation payload systems for SPACELAB and free flyer missions to study solidification and crystal growth and to process metal/alloys, glasses/ceramics, and chemicals and biologicals.
van 't Hag, Leonie; Gras, Sally L; Conn, Charlotte E; Drummond, Calum J
2017-05-22
Ordered amphiphile self-assembly materials with a tunable three-dimensional (3D) nanostructure are of fundamental interest, and crucial for progressing several biological and biomedical applications, including in meso membrane protein crystallization, as drug and medical contrast agent delivery vehicles, and as biosensors and biofuel cells. In binary systems consisting of an amphiphile and a solvent, the ability to tune the 3D cubic phase nanostructure, lipid bilayer properties and the lipid mesophase is limited. A move beyond the binary compositional space is therefore required for efficient engineering of the required material properties. In this critical review, the phase transitions upon encapsulation of more than 130 amphiphilic and soluble additives into the bicontinuous lipidic cubic phase under excess hydration are summarized. The data are interpreted using geometric considerations, interfacial curvature, electrostatic interactions, partition coefficients and miscibility of the alkyl chains. The obtained lyotropic liquid crystal engineering design rules can be used to enhance the formulation of self-assembly materials and provides a large library of these materials for use in biomedical applications (242 references).
Sanjeewa, Liurukara D.; Garlea, Vasile O.; McGuire, Michael A.; ...
2016-06-06
The descloizite-type compound, SrMn(VO 4)(OH), was synthesized as large single crystals (1-2mm) using a high-temperature high-pressure hydrothermal technique. X-ray single crystal structure analysis reveals that the material crystallizes in the acentric orthorhombic space group of P2 12 12 1 (no. 19), Z = 4. The structure exhibits a one-dimensional feature, with [MnO 4] chains propagating along the a-axis which are interconnected by VO 4 tetrahedra. Raman and infrared spectra were obtained to identify the fundamental vanadate and hydroxide vibrational modes. Magnetization data reveal a broad maximum at approximately 80 K, arising from one-dimensional magnetic correlations with intrachain exchange constant ofmore » J/k B = 9.97(3) K between nearest Mn neighbors and a canted antiferromagnetic behavior below T N = 30 K. Single crystal neutron diffraction at 4 K yielded a magnetic structure solution in the lower symmetry of the magnetic space group P2 1 with two unique chains displaying antiferromagnetically ordered Mn moments oriented nearly perpendicular to the chain axis. Lastly, the presence of the Dzyaloshinskii Moriya antisymmetric exchange interaction leads to a slight canting of the spins and gives rise to a weak ferromagnetic component along the chain direction.« less
STS-72 Space Shuttle Mission Report
NASA Technical Reports Server (NTRS)
Fricke, Robert W., Jr.
1996-01-01
The STS-72 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the seventy-fourth flight of the Space Shuttle Program, the forty-ninth flight since the return-to-flight, and the tenth flight of the Orbiter Endeavour (OV-105). In addition to the Orbiter, the flight vehicle consisted of an ET that was designated ET-75; three Block I SSME's that were designated as serial numbers 2028, 2039, and 2036 in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-077. The RSRM's, designated RSRM-52, were installed in each SRB and the individual RSRM's were designated as 36OW052A for the left SRB, and 36OW052B for the right SRB. Appendix A lists the sources of data, both formal and informal, that were used to prepare this report. The primary objectives of this flight were to retrieve the Japanese Space Flyer Unit (JSFU) and deploy and retrieve the Office of Aeronautics and Space Technology-Flyer (OAST-Flyer). Secondary objectives were to perform the operations of the Shuttle Solar Backscatter Ultraviolet (SSBUV/A) experiment, Shuttle Laser Altimeter (SLA)/get-Away Special (GAS) payload, Physiological and Anatomical Rodent Experiment/National Institutes of Health-Cells (STL/NIH-C) experiment, Protein Crystal Growth-Single Locker Thermal Enclosure System (PCG-STES) experiment, Commercial Protein Crystal Growth (CPCG) payload and perform two extravehicular activities (EVA's) to demonstrate International Space Station Alpha (ISSA) assembly techniques). Appendix B provides the definition of acronyms and abbreviations used throughout the report. All times during the flight are given in Greenwich mean time (GMT) and mission elapsed time (MET).
Protein Crystal Recombinant Human Insulin
NASA Technical Reports Server (NTRS)
1994-01-01
The comparison of protein crystal, Recombiant Human Insulin; space-grown (left) and earth-grown (right). On STS-60, Spacehab II indicated that space-grown crystals are larger and of greater optical clarity than their earth-grown counterparts. Recombiant Human Insulin facilitates the incorporation of glucose into cells. In diabetics, there is either a decrease in or complete lack of insulin, thereby leading to several harmful complications. Principal Investigator is Larry DeLucas.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Raghunathan, Kannan; Vago, Frank S.; Ball, Terry
2010-01-12
EpsH is a minor pseudopilin protein of the Vibrio cholerae type II secretion system. A truncated form of EpsH with a C-terminal noncleavable His tag was constructed and expressed in Escherichia coli, purified and crystallized by sitting-drop vapor diffusion. A complete data set was collected to 1.71 {angstrom} resolution. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 53.39, b = 71.11, c = 84.64 {angstrom}. There were two protein molecules in the asymmetric unit, which gave a Matthews coefficient V{sub M} of 2.1 {angstrom}{sup 3} Da{sup -1}, corresponding to 41.5% solvent content.
Overexpression, purification, crystallization and preliminary X-ray studies of Vibrio cholerae EpsG
Jens, Jason; Raghunathan, Kannan; Vago, Frank; Arvidson, Dennis
2009-01-01
EpsG is the major pseudopilin protein of the Vibrio cholerae type II secretion system. An expression plasmid that encodes an N-terminally truncated form of EpsG with a C-terminal noncleavable His tag was constructed. Recombinant EpsG was expressed in Escherichia coli; the truncated protein was purified and crystallized by hanging-drop vapor diffusion against a reservoir containing 6 mM zinc sulfate, 60 mM MES pH 6.5, 15% PEG MME 550. The crystals diffracted X-rays to a resolution of 2.26 Å and belonged to space group P21, with unit-cell parameters a = 88.61, b = 70.02, c = 131.54 Å. PMID:19478449
Crystal growth in a low gravity environment
NASA Technical Reports Server (NTRS)
Carruthers, J. R.
1977-01-01
Crystal growth in microgravity possesses several distinct technological advantages over earth-bound processes; containerless handling and reduction of density gradient driven as well as sedimentation flows. Experiments performed in space to date have been basically reproductions of processes currently used on earth and the results have clarified our understanding of crystal growth dynamics. In addition, both unresolved problems and areas requiring further study on earth have been identified. Future work in space processing of materials must address these areas of study as soon as possible if the full potential of a space environment to develop new techniques and materials is to be realized.
1997-09-08
United States Microgravity Payload-4 (USMP-4) experiments are prepared to be flown on Space Shuttle mission STS-87 in the Space Station Processing Facility at Kennedy Space Center (KSC). This horizontal tube is known as MEPHISTO, the French acronym for a cooperative American-French investigation of the fundamentals of crystal growth. This experiment, designed for the study of solidification (or freezing) during the growth cycle of liquid materials used for semiconductor crystals, aims to aid in the development of techniques for growing higher quality crystals on Earth. All STS-87 experiments are scheduled for launch on Nov. 19 from KSC
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meining, Winfried, E-mail: wim@csb.ki.se; Scheuring, Johannes; Fischer, Markus
2006-06-01
SecA ATPase from E. faecalis has been cloned, overexpressed, purified and crystallized. Crystals belong to space group C2 and diffract to 2.4 Å resolution. The gene coding for SecA from Enterococcus faecalis was cloned and overexpressed in Escherichia coli. In this protein, the lysine at position 6 was replaced by an asparagine in order to reduce sensitivity towards proteases. The modified protein was purified and crystallized. Crystals diffracting to 2.4 Å resolution were obtained using the vapour-diffusion technique. The crystals belong to the monoclinic space group C2, with unit-cell parameters a = 203.4, b = 49.8, c = 100.8 Å,more » α = γ = 90.0, β = 119.1°. A selenomethionine derivative was prepared and is currently being tested in crystallization trials.« less
Fabrication of a 20.5-inch-diameter segmented silicon annular optic prototype for the ROMA program
NASA Astrophysics Data System (ADS)
Hassell, Frank R.; Groark, Frank M.
1995-10-01
Recent advancements in single crystal silicon material science and fabrication capabilities and very low absorption (VLA) multi-layer dielectric coating technology have led to the development of uncooled, large aperture, high power mirrors for high energy laser (HEL) systems. Based on this success, a segmented single-crystal silicon substrate concept has been selected as the baseline fabrication approach for uncooled 1.2 meter diameter resonator annular optics for the Alpha space based high energy laser. The objective of this Resonator Optics Materials Assessment (ROMA) task was to demonstrate all of the key fabrication processes required to fabricate the full sized annular optics for the Alpha space based high energy laser. This paper documents the fabrication of a half-scale annular optic prototype (AOP) of the Alpha laser rear cone.
Large charged drop levitation against gravity
NASA Technical Reports Server (NTRS)
Rhim, Won-Kyu; Chung, Sang Kun; Hyson, Michael T.; Trinh, Eugene H.; Elleman, Daniel D.
1987-01-01
A hybrid electrostatic-acoustic levitator that can levitate and manipulate a large liquid drop in one gravity is presented. To the authors' knowledge, this is the first time such large drops (up to 4 mm in diameter in the case of water) have been levitated against 1-gravity. This makes possible, for the first time, many new experiments both in space and in ground-based laboratories, such as 1)supercooling and superheating, 2) containerless crystal growth from various salt solutions or melts, 3) drop dynamics of oscillating or rotating liquid drops, 4) drop evaporation and Rayleigh bursting, and 5) containerless material processing in space. The digital control system, liquid drop launch process, principles of electrode design, and design of a multipurpose room temperature levitation chamber are described. Preliminary results that demonstrate drop oscillation and rotation, and crystal growth from supersaturated salt solutions are presented.
Prakash, M; Geetha, D; Lydia Caroline, M
2013-04-15
Single crystals of L-phenylalanine-benzoic acid (LPBA) were successfully grown from aqueous solution by solvent evaporation technique. Purity of the crystals was increased by the method of recrystallization. The XRD analysis confirms that the crystal belongs to the monoclinic system with noncentrosymmetric space group P21. The chemical structure of compound was established by FT-NMR technique. The presence of functional groups was estimated qualitatively by Fourier transform infrared analysis (FT-IR). Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 254 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 6.91 eV. Thermal behavior has been studied with TGA/DTA analyses. The existence of second harmonic generation (SHG) efficiency was found to be 0.56 times the value of KDP. The dielectric behavior of the sample was also studied for the first time. Copyright © 2013 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Arshad, Suhana; Pillai, Renjith Raveendran; Zainuri, Dian Alwani; Khalib, Nuridayanti Che; Razak, Ibrahim Abdul; Armaković, Stevan; Armaković, Sanja J.
2017-09-01
In the present study, single crystals of E)-3-(3,5-dichlorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one, were prepared and structurally characterized by single crystal X-ray diffraction analysis. The molecular structure crystallized in monoclinic crystal system with P21/c space group. Sensitivity of the title molecule towards electrophilic attacks has been examined by calculations of average localized ionization energies (ALIE) and their mapping to electron density surface. Further determination of atoms that could be important reactive centres has been performed by calculations of Fukui functions. Sensitivity of title molecule towards autoxidation and hydrolysis mechanisms has been assessed by calculations of bond dissociation energies and radial distribution functions (RDF), respectively. Also, in order to explore possible binding mode of the title compound towards Dihydrofolate reductase enzyme, we have utilized in silico molecular docking to explore possible binding modes of the title compound with the DHFR enzyme.
NASA Technical Reports Server (NTRS)
Grodzka, P. G.; Pond, J. E.; Spradley, J. W.; Johnson, M. H.
1976-01-01
The Dendrite Remelting Rocket Experiment was performed aboard a Black Brant VC Sounding Rocket during a period which gravity levels of approximately 0.00001 g prevailed. The experiment consisted of cooling an aqueous ammonium chloride solution in a manner such that crystallization of ammonium chloride crystals proceeded throughout a three minute period of zero-g. The crystallization process during flight was recorded on 35 mm panatomic-x film. A number of ground crystallizations were similarly recorded for comparison purposes. The convective and thermal conditions in aqueous and metallic liquid systems were assessed under conditions of the flight experiment to help establish the relevance of the rocket experiment to metals casting phenomena. The results indicate that aqueous or metallic convective velocities in the Dendrite Remelting Rocket Experiment cell are of insignificant magnitudes at the 0.0001 to 0.00001 g levels of the experiment. The crystallization phenomena observed in the Rocket Experiment, therefore, may be indicative of how metals will solidify in low-g.
NASA Astrophysics Data System (ADS)
Nagapandiselvi, P.; Baby, C.; Gopalakrishnan, R.
2015-09-01
A new semiorganic compound namely, 2-carboxy pyridinium dihydrogen phosphate (2CPDP) was synthesised and grown as single crystals by slow evaporation solution growth technique. Single crystal XRD showed that 2CPDP belongs to monoclinic crystal system with space group P21/n. The molecular structure was further confirmed by modern spectroscopic techniques like FT-NMR (1H, 13C &31P), FT-IR, UV-Vis-NIR and Fluorescence. The UV-Vis-NIR analysis revealed suitability of the crystal for nonlinear optical applications. The photo active nature of the material is established from fluorescence studies. TG-DSC analysis showed that 2CPDP was thermally stable up to 170 °C. The dependence of dielectric properties on frequency and temperature were also studied. Nonlinear optical absorption determined from open aperture Z-Scan analysis by employing picosecond Nd-YAG laser, revealed that 2CPDP can serve as a promising candidate for optical limiting applications.
NASA Astrophysics Data System (ADS)
Whittington, A. G.; Sehlke, A.; Speck, A. K.
2017-12-01
Dust that coalesces to form planetary systems originates around dying stars, before passing into the interstellar medium (ISM). Historically, observations of broad smooth features in the 10-µm region suggested that dust in circumstellar regions, and in the ISM, was mostly amorphous rather than crystalline. With improved space telescope capabilities, crystalline silicates were discovered in the circumstellar regions around both young and old stars, although they remain undetected in the ISM. Despite intensive study the precise conditions that lead to the formation of crystalline silicates are still unknown, and their absence in the ISM remains problematic. Here we show that recalescence (spontaneous reheating) of rapidly crystallizing dust can explain the formation and apparent disappearance of crystalline silicates in space. We have documented recalescence in rapidly crystallizing Mg-rich silicate melts, with local heating at the crystallization front exceeding 160˚C in some cases. In circumstellar dust shells, amorphous grains with similar compositions condense at temperatures near their glass transition, and if they crystallize, they will recalesce. The higher temperature (T) of newly crystallized dust allows crystalline spectral features to be seen, because flux emitted depends on T4. After cooling to ambient temperature, crystalline spectral features in the ISM are concealed by volumetrically dominant amorphous dust. Our results explain the existence of crystalline silicate pre-solar grains, which are older than the solar system, and have implications for radiative transfer modeling and hydrodynamics of dusty environments, which are sensitive to small variations in optical properties. Our observations of mm-scale temperature differences up to 100˚C in cooling lava suggest that thermal imaging of basaltic lava flows needs to be conducted with mm-scale spatial resolution (see figure; crucible is 5mm diameter). Temperatures recorded with low spatial resolution, which average cooler melt and hotter crystals in a single pixel, will systematically overestimate the temperature of the liquid phase. Only the surface of a lava flow is likely to cool quickly enough for recalescence to occur, but this is precisely the part of the lava that is monitored by thermal imaging.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brüx, Christian; Niefind, Karsten; Ben-David, Alon
2005-12-01
The crystallization and preliminary X-ray analysis of a β-d-xylosidase from G. stearothermophilus T-6, a family 43 glycoside hydrolase, is described. Native and catalytic inactive mutants of the enzymes were crystallized in two different space groups, orthorhombic P2{sub 1}2{sub 1}2 and tetragonal P4{sub 1}2{sub 1}2 (or the enantiomorphic space group P4{sub 3}2{sub 1}2), using a sensitive cryoprotocol. The latter crystal form diffracted X-rays to a resolution of 2.2 Å. β-d-Xylosidases (EC 3.2.1.37) are hemicellulases that cleave single xylose units from the nonreducing end of xylooligomers. In this study, the crystallization and preliminary X-ray analysis of a β-d-xylosidase from Geobacillus stearothermophilus T-6more » (XynB3), a family 43 glycoside hydrolase, is described. XynB3 is a 535-amino-acid protein with a calculated molecular weight of 61 891 Da. Purified recombinant native and catalytic inactive mutant proteins were crystallized and cocrystallized with xylobiose in two different space groups, P2{sub 1}2{sub 1}2 (unit-cell parameters a = 98.32, b = 99.36, c = 258.64 Å) and P4{sub 1}2{sub 1}2 (or the enantiomorphic space group P4{sub 3}2{sub 1}2; unit-cell parameters a = b = 140.15, c = 233.11 Å), depending on the detergent. Transferring crystals to cryoconditions required a very careful protocol. Orthorhombic crystals diffract to 2.5 Å and tetragonal crystals to 2.2 Å.« less
Polymer Light-Emitting Diode (PLED) Process Development
2003-12-01
conclusions and recommendations for Phase II of the Flexible Display Program. 15. SUBJECT TERMS LIGHT EMITTING DIODES LIQUID CRYSTAL DISPLAY SYSTEMS...space for Phase I and II confined by backplane complexity and substrate form...12 Figure 6. Semi automated I-V curve measurement setup consisting of Keithley power supply, computer and
NASA Astrophysics Data System (ADS)
Priyadharshini, A.; Kalainathan, S.
2018-04-01
2-(4-fluorobenzylidene) malononitrile (FBM), an organic third order nonlinear (TONLO) single crystal with the dimensions of 32 × 7 × 11 mm3, has been successfully grown in acetone solution by slow evaporation technique at 35 °C. The crystal system (triclinic), space group (P-1) and crystalline purity of the titular crystal were measured by single crystal and powder X-ray diffraction, respectively. The molecular weight and the multiple functional groups of the FBM material were confirmed through the mass and FT-IR spectral analysis. UV-Vis-NIR spectral study enroles that the FBM crystal exhibits excellent transparency (83%) in the entire visible and near infra-red region with a wide bandgap 2.90 eV. The low dielectric constant (εr) value of FBM crystal is appreciable for microelectronics industry applications. Thermal stability and melting point (130.09 °C) were ascertained by TGA-DSC analysis. The laser-induced surface damage threshold (LDT) value of FBM specimen is found to be 2.14 GW/cm2, it is fairly good compared to other reported NLO crystals. The third - order nonlinear optical character of the FBM crystal was confirmed through the typical single beam Z-scan technique. All these finding authorized that the organic crystal of FBM is favorably suitable for NLO applications.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dhanalakshmi, B.; Ponnusamy, S., E-mail: suruponnus@gmail.com; Muthamizhchelvan, C.
2015-10-15
Highlights: • EDA4NPH crystal possesses negative nonlinear refractive index. • The crystal exhibits high third-order NLO susceptibility. • Wide transparency of the crystal makes it suitable for NLO applications. • Dielectric studies substantiate the suitability for electro-optic applications. • The crystal possesses suitable mechanical strength for device fabrication. - Abstract: Bulk crystals of the charge-transfer complex, ethylenediamine-4-nitrophenolate monohydrate, were grown by slow solvent evaporation method from aqueous solution at room temperature. The X-ray diffraction measurements showed that the crystal belongs to centrosymmetric space group C2/c of monoclinic system. The functional groups in the complex were identified using FTIR, FTRaman andmore » FTNMR analyses. The Z-scan measurements revealed the negative nonlinear refractive index of the crystal. The nonlinear absorption coefficient and third order nonlinear optical susceptibility calculated from the measurements were −3.5823 × 10{sup −3} cm/W and 2.3762 × 10{sup −6} esu respectively. The crystal was shown to be highly transparent above 366 nm by UV–vis spectroscopy and a yellow fluorescence was observed from PL spectrum. The TG–DTA and DSC analyses showed that the crystal is thermally stable up to 117.4 °C. The crystals were characterized by dielectric, etching and microhardness studies.« less
The Effects of Gravity on the Crystallization Behavior of Heavy Metal Fluoride Glasses
NASA Technical Reports Server (NTRS)
Tucker, Dennis S.; Smith, Guy A.
2004-01-01
Heavy metal fluoride glasses are used in such applications as fiber lasers and laser amplifiers. ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) is one of the more commonly used heavy metal fluoride glasses. ZBLAN is an infrared transmitter and has a theoretical attenuation coefficient of 0.002 db/km. However, due to impurities and small crystallites this attenuation coefficient has not been achieved to date. ZBLAN is a fragile glass which can lead to rapid crystallization, if the glass is not cooled rapidly to below the glass transition temperature or if the glass is reheated near the crystallization temperature for any period of time. Studies carried on at Marshall Space Flight Center and the University of Alabama in Huntsville since 1993 have shown that heating ZBLAN glass at the crystallization temperature in reduced gravity results in a suppression of crystallization when compared to ZBLAN processed in unit gravity. These studies utilized NASA's KC-135 aircraft and the Conquest sounding rocket. In the first series of experiments, short lengths of ZBLAN fiber were heated to the crystallization temperature in reduced gravity on board the KC- 135 and the Conquest sounding rocket and compared with fibers heated in unit gravity. The fibers processed in reduced gravity showed no evidence of crystallization when studied with x-ray diffraction and scanning electron microscopy. However, the fibers processed in unit gravity were completely crystallized. Subsequent experiments included heating small pieces of ZBLAN glass at the crystallization temperature while viewing with a video camera to follow the crystallization phenomenon. In this experiment crystallization was observed in reduced gravity, however, it was suppressed when compared to heating in unit gravity. In the most recent experiment on board the KC-135, rapid thermal analysis of ZBLAN was performed. A mechanism to explain the observations has been proposed. This mechanism is based on shear thinning whereby, the glass undergoes a reduction in viscosity in the 10(exp 5) - 10(exp 7) poise range, allowing more rapid diffusion and thus crystallization. It is proposed that this mechanism is suppressed in reduced gravity. An experiment is presently being conducted to test this theory. With increased knowledge of ZBLAN behavior in reduced gravity, three low earth orbit tiber drawing facilities have been designed. One would be suitable for use on the International Space Station, another while aboard the Space Shuttle and the third system is a fully automated facility which would operate independently of the ISS or Shuttle in a free float mode. The primary benefits of free floating a facility in LEO includes a higher quality of microgravity and reduced safety concerns since it is not in a manned environment.
NASA Astrophysics Data System (ADS)
Shanmugavadivu, T.; Dhandapani, M.; Naveen, S.; Lokanath, N. K.
2017-09-01
An organic NLO active material N,N‧-diphenylguanidinium picrate: diacetone solvate (C13H14N3+. C6H2N3O7-. 2C3H6O) (DPGPD) was synthesized and single crystals were grown by slow evaporation-solution growth technique at room temperature. DPGPD crystallizes in monoclinic crystal system with noncentrosymmetric space group, Cc confirmed by single crystal X-ray diffraction analysis. The presence of various functional groups was identified from FT-IR spectral analysis and the proton transfer during the formation of compound was confirmed by NMR spectroscopic techniques. The thermal stability was investigated by TG/DTA analyses. Optical transmittance was measured by UV-Vis-NIR spectroscopy and band gap energy was calculated. Photoluminescence spectrum was used to explore its applicability towards laser diodes. Dielectric property of the material was ascertained at different temperatures and it is found that the grown crystal has higher dielectric constant in low frequencies. Photoconductivity study revealed that DPGPD exhibits positive photoconductivity. SHG property was found to be 0.6 times higher than that of KDP.
NASA Technical Reports Server (NTRS)
Patterson, Richard L.; Hammoud, Ahmad
2011-01-01
Data acquisition and control systems depend on timing signals for proper operation and required accuracy. These clocked signals are typically provided by some form of an oscillator set to produce a repetitive, defined signal at a given frequency. Crystal oscillators are commonly used because they are less expensive, smaller, and more reliable than other types of oscillators. Because of the inherent characteristics of the crystal, the oscillators exhibit excellent frequency stability within the specified range of operational temperature. In some cases, however, some compensation techniques are adopted to further improve the thermal stability of a crystal oscillator. Very limited data exist on the performance and reliability of commercial-off-the-shelf (COTS) crystal oscillators at temperatures beyond the manufacturer's specified operating temperature range. This information is very crucial if any of these parts were to be used in circuits designed for use in space exploration missions where extreme temperature swings and thermal cycling are encountered. This report presents the results of the work obtained on the operation of Silicon Laboratories crystal oscillator, type Si530, under specified and extreme ambient temperatures.
2012-01-01
2002. [2] Max Blosser. Fundamental Modeling and Thermal Performance Issues for Metal- lic Thermal Protection System Concept. Journal of Spacecraft and...Directorate (AFRL/RX, Metallic Thermal Protection System Program, Universal Technology Corporation/AFRL Grant, ProgramManagers: Todd Warren and Reji John...retired Space Shuttle program were built with a Thermal Protection System (TPS) to withstand heating during atmo- spheric reentry. The partially
A comparative study of the influence of buoyancy driven fluid flow on GaAs crystal growth
NASA Technical Reports Server (NTRS)
Kafalas, J. A.; Bellows, A. H.
1988-01-01
A systematic investigation of the effect of gravity driven fluid flow on GaAs crystal growth was performed. It includes GaAs crystal growth in the microgravity environment aboard the Space Shuttle. The program involves a controlled comparative study of crystal growth under a variety of earth based conditions with variable orientation and applied magnetic field in addition to the microgravity growth. Earth based growth will be performed under stabilizing as well as destabilizing temperature gradients. The boules grown in space and on earth will be fully characterized to correlate the degree of convection with the distribution of impurities. Both macro- and micro-segregation will be determined. The space growth experiment will be flown in a self-contained payload container through NASA's Get Away Special program.
Reduce Fluid Experiment System: Flight data from the IML-1 Mission
NASA Technical Reports Server (NTRS)
Workman, Gary L.; Harper, Sabrina
1995-01-01
Processing and data reduction of holographic images from the International Microgravity Laboratory 1 (IML-1) presents some interesting challenges in determining the effects of microgravity on crystal growth processes. Use of several processing techniques, including the Computerized Holographic Image Processing System and the Software Development Package (SDP-151) will provide fundamental information for holographic and schlieren analysis of the space flight data.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Molitor, Christian; Mauracher, Stephan Gerhard; Rompel, Annette, E-mail: annette.rompel@univie.ac.at
2015-05-22
Latent and active aurone synthase purified from petals of C. grandiflora (cgAUS1) were crystallized. The crystal quality of recombinantly expressed latent cgAUS1 was significantly improved by co-crystallization with the polyoxotungstate Na{sub 6}[TeW{sub 6}O{sub 24}] within the liquid–liquid phase-separation zone. Aurone synthase (AUS), a member of a novel group of plant polyphenol oxidases (PPOs), catalyzes the oxidative conversion of chalcones to aurones. Two active cgAUS1 (41.6 kDa) forms that differed in the level of phosphorylation or sulfation as well as the latent precursor form (58.9 kDa) were purified from the petals of Coreopsis grandiflora. The differing active cgAUS1 forms and themore » latent cgAUS1 as well as recombinantly expressed latent cgAUS1 were crystallized, resulting in six different crystal forms. The active forms crystallized in space groups P2{sub 1}2{sub 1}2{sub 1} and P12{sub 1}1 and diffracted to ∼1.65 Å resolution. Co-crystallization of active cgAUS1 with 1,4-resorcinol led to crystals belonging to space group P3{sub 1}21. The crystals of latent cgAUS1 belonged to space group P12{sub 1}1 and diffracted to 2.50 Å resolution. Co-crystallization of recombinantly expressed pro-AUS with the hexatungstotellurate(VI) salt Na{sub 6}[TeW{sub 6}O{sub 24}] within the liquid–liquid phase separation zone significantly improved the quality of the crystals compared with crystals obtained without hexatungstotellurate(VI)« less
Carbonate-based zeolitic imidazolate framework for highly selective CO2 capture.
Basnayake, Sajani A; Su, Jie; Zou, Xiadong; Balkus, Kenneth J
2015-02-16
In this study, we report the formation of a new crystal structure, ZIF-CO3-1, which results from the reaction of Zn(2+), 2-methylimidazole, and carbonate. ZIF-CO3-1 can be synthesized solvothermally in N,N-dimethylformamide (DMF)/water (H2O) or by utilizing of CO2 gas at various temperatures in DMF/H2O or H2O. This reaction selectively consumes CO2 because CO2 is incorporated in the ZIF as carbonate. CO2 can be quantitatively released by acidifying the ZIF. Powder X-ray diffraction, single-crystal X-ray diffraction, FTIR spectroscopy, scanning electron microscopy, elemental analysis, and thermogravimetric analysis were used to characterize the ZIF structure. ZIF-CO3-1 (chemical formula C9H10N4O3Zn2), crystallizes in the orthorhombic crystal system with noncentrosymmetric space group Pba2.
High Resolution Displays Using NCAP Liquid Crystals
NASA Astrophysics Data System (ADS)
Macknick, A. Brian; Jones, Phil; White, Larry
1989-07-01
Nematic curvilinear aligned phase (NCAP) liquid crystals have been found useful for high information content video displays. NCAP materials are liquid crystals which have been encapsulated in a polymer matrix and which have a light transmission which is variable with applied electric fields. Because NCAP materials do not require polarizers, their on-state transmission is substantially better than twisted nematic cells. All dimensional tolerances are locked in during the encapsulation process and hence there are no critical sealing or spacing issues. By controlling the polymer/liquid crystal morphology, switching speeds of NCAP materials have been significantly improved over twisted nematic systems. Recent work has combined active matrix addressing with NCAP materials. Active matrices, such as thin film transistors, have given displays of high resolution. The paper will discuss the advantages of NCAP materials specifically designed for operation at video rates on transistor arrays; applications for both backlit and projection displays will be discussed.
Synthesis, crystal structure and electronic structure of the binary phase Rh2Cd5
NASA Astrophysics Data System (ADS)
Koley, Biplab; Chatterjee, S.; Jana, Partha P.
2017-02-01
A new phase in the Rh-Cd binary system - Rh2Cd5 has been identified and characterized by single crystal X-ray diffraction and Energy dispersive X-ray analysis. The stoichiometric compound Rh2Cd5 crystallizes with a unit cell containing 14 atoms, in the orthorhombic space group Pbam (55). The crystal structure of Rh2Cd5 can be described as a defect form of the In3Pd5 structure with ordered vacancies, formed of two 2D atomic layers with the stacking sequence: ABAB. The A type layers consist of (3.6.3.6)-Kagomé nets of Cd atoms while the B type layers consist of (35) (37)- nets of both Cd and Rh atoms. The stability of this line phase is investigated by first principle electronic structure calculations on the model of ordered Rh2Cd5.
X-ray Crystallography Facility
NASA Technical Reports Server (NTRS)
1999-01-01
University of Alabama engineer Lance Weiss briefs NASA astronaut Dr. Bornie Dunbar about the design and capabilities of the X-ray Crystallography Facility under development at the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, AL, April 21, 1999. The X-ray Crystallography Facility is designed to speed the collection of protein structure information from crystals grown aboard the International Space Station. By measuring and mapping the protein crystal structure in space, researchers will avoid exposing the delicate crystals to the rigors of space travel and make important research data available to scientists much faster. The X-ray Crystallography facility is being designed and developed by the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, a NASA Commercial Space Center.
X-ray Crystallography Facility
NASA Technical Reports Server (NTRS)
1999-01-01
University of Alabama engineer Stacey Giles briefs NASA astronaut Dr. Bornie Dunbar about the design and capabilities of the X-ray Crystallography Facility under development at the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, AL, April 21, 1999. The X-ray Crystallography Facility is designed to speed the collection of protein structure information from crystals grown aboard the International Space Station. By measuring and mapping the protein crystal structure in space, researchers will avoid exposing the delicate crystals to the rigors of space travel and make important research data available to scientists much faster. The X-ray Crystallography facility is being designed and developed by the Center for Macromolecular Crystallography of the University of Alabama at Birmingham, a NASA Commercial Space Center.
Survey Analysis of Materials Processing Experiments Aboard STS-47: Spacelab J
NASA Technical Reports Server (NTRS)
Sharpe, R. J.; Wright, M. D.
2009-01-01
This Technical Memorandum (TM) is a survey outline of materials processing experiments aboard Space Shuttle Mission STS-47: Spacelab J, a joint venture between NASA and the National Space Development Agency of Japan. The mission explored materials processing experiments including electronics and crystal growth materials, metals and alloys, glasses and ceramics, and fluids. Experiments covered include Growth of Silicone Spherical Crystals and Surface Oxidation, Growth Experiment of Narrow Band-Gap Semiconductor Lead-Tin-Tellurium Crystals in Space, Study on Solidification of Immiscible Alloys, Fabrication of Very-Low-Density, High-Stiffness Carbon Fiber/Aluminum Hybridized Composites, High Temperature Behavior of Glass, and Study of Bubble Behavior. The TM underscores the historical significance of these experiments in the context of materials processing in space.
Advanced protein crystal growth programmatic sensitivity study
NASA Technical Reports Server (NTRS)
1992-01-01
The purpose of this study is to define the costs of various APCG (Advanced Protein Crystal Growth) program options and to determine the parameters which, if changed, impact the costs and goals of the programs and to what extent. This was accomplished by developing and evaluating several alternate programmatic scenarios for the microgravity Advanced Protein Crystal Growth program transitioning from the present shuttle activity to the man tended Space Station to the permanently manned Space Station. These scenarios include selected variations in such sensitivity parameters as development and operational costs, schedules, technology issues, and crystal growth methods. This final report provides information that will aid in planning the Advanced Protein Crystal Growth Program.
NASA Technical Reports Server (NTRS)
Casale, Elena; He, Xiao-Min; Snyder, Robert S.; Carter, Daniel C.; Wenisch, Elisabeth; Jungbauer, Alois; Tauer, Christa; Ruker, Florian; Righetti, Pier Giorgio
1990-01-01
A monoclonal IgG antibody directed against gp 41 from the human immunodeficiency virus (HIV-1) has been crystallized in both intact and Fab forms. Crystals of the intact antibody grow as tetragonal-like prisms too small for conventional X-ray analysis. However, the Fab portion of the antibody produces suitable platelike crystals which belong to the space group P2(1)2(1)2(1) with unit cell constants of a = 66.5 A, b = 74.3 A, and c = 105.3 A. There is one molecule of Fab in the asymmetric unit. The Fab crystals show diffraction to d-spacings less than 3.0 A.
Advantages of thin silicon solar cells for use in space
NASA Technical Reports Server (NTRS)
Denman, O. S.
1978-01-01
A system definition study on the Solar Power Satellite System showed that a thin, 50 micrometers, silicon solar cell has significant advantages. The advantages include a significantly lower performance degradation in a radiation environment and high power-to-mass ratios. The advantages of such cells for an employment in space is further investigated. Basic questions concerning the operation of solar cells are considered along with aspects of radiation induced performance degradation. The question arose in this connection how thin a silicon solar cell had to be to achieve resistance to radiation degradation and still have good initial performance. It was found that single-crystal silicon solar cells could be as thin as 50 micrometers and still develop high conversion efficiencies. It is concluded that the use of 50 micrometer silicon solar cells in space-based photovoltaic power systems would be advantageous.
1998-06-16
Eddie Snell (standing), Post-Doctoral Fellow the National Research Council (NRC),and Marc Pusey of Marshall Space Flight Center (MSFC) use a reciprocal space mapping diffractometer for marcromolecular crystal quality studies. The diffractometer is used in mapping the structure of marcromolecules such as proteins to determine their structure and thus understand how they function with other proteins in the body. This is one of several analytical tools used on proteins crystalized on Earth and in space experiments. Photo credit: NASA/Marshall Space Flight Center (MSFC)
SKYLAB (SL)-3 - EXPERIMENT HARDWARE
1973-11-08
S74-19677 (April 1974) --- This crystal of Germanium Selenide (GeSe) was grown under weightless conditions in an electric furnace aboard the Skylab space station. Experiment M556, Vapor Growth of IV-VI Compounds, was conducted as a comparative test of GeSe crystals grown on Earth and those grown in a weightless environment. Skylab postflight results indicate that crystals grown in a zero-gravity situation demonstrate greater growth and better composite structure than those grown in ground-bases laboratories. The GeSe crystal shown here is 20 millimeters long, the largest crystal ever grown on Earth or in space. Principal Investigator for Experiment M556 is Dr. Harry Wiedemaier, Rensselaer Polytechnic Institute, Troy, New York. (See NASA photograph S74-19676 for an example of an Earth-grown Germanium Selenide crystal.) Photo credit: NASA
NASA Technical Reports Server (NTRS)
Carlson, Frederick
1990-01-01
The objective of this theoretical research effort was to improve the understanding of the growth of Pb(x)Sn(1-x)Te and especially how crystal quality could be improved utilizing the microgravity environment of space. All theoretical growths are done using the vertical Bridgman method. It is believed that improved single crystal yields can be achieved by systematically identifying and studying system parameters both theoretically and experimentally. A computational model was developed to study and eventually optimize the growth process. The model is primarily concerned with the prediction of the thermal field, although mass transfer in the melt and the state of stress in the crystal were of considerable interest. The evolution is presented of the computer simulation and some of the important results obtained. Diffusion controlled growth was first studied since it represented a relatively simple, but nontheless realistic situation. In fact, results from this analysis prompted a study of the triple junction region where the melt, crystal, and ampoule wall meet. Since microgravity applications were sought because of the low level of fluid movement, the effect of gravitational field strength on the thermal and concentration field was also of interest. A study of the strength of coriolis acceleration on the growth process during space flight was deemed necessary since it would surely produce asymmetries in the flow field if strong enough. Finally, thermosolutal convection in a steady microgravity field for thermally stable conditions and both stable and unstable solutal conditions was simulated.
Dopant Segregation in Earth- and Space-Grown InP Crystals
NASA Astrophysics Data System (ADS)
Danilewsky, Andreas Nikolaus; Okamoto, Yusuke; Benz, Klaus Werner; Nishinaga, Tatau
1992-07-01
Macro- and microsegregation of sulphur in InP crystals grown from In solution by the travelling heater method under microgravity and normal gravity are analyzed using spatially resolved photoluminescence. Whereas the macrosegregation in earth- as well as space-grown crystals is explained by conventional steady-state models based on the theory of Burton, Prim and Slichter (BPS), the microsegregation can only be understood in terms of the non-steady-state step exchange model.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Yuntao; Chakoumakos, Bryan C.; Shi, Hongliang
A self-activated Cs 4YbI 6 single crystal was grown by the vertical Bridgman method. Crystal structure refinements verified the phase purity and the trigonal crystal system with a space group of more » $$\\bar{R}$$3 c. By using differential scanning calorimetry, the melting and crystallization points were determined to be 550 and 510 °C, respectively. Luminescence and scintillation properties were systematically studied. Upon ultraviolet light (360 nm) excitation, the Cs 4YbI 6 crystal exhibits bluish-green emission centered at 450 and 480 nm due to spin-allowed and spin-forbidden transitions of Yb 2+ activators. The lifetimes of the corresponding emission bands at room temperature are tens and hundreds of nanoseconds, respectively. X-ray excited radioluminescence spectrum is dominated by the spin-forbidden transition of Yb 2+ at 480 nm. The absolute light yield is 2700 ± 200 photons/MeV with a principal scintillation decay time of 33 ns. In conclusion, the physical explanation for the low light yield observed is proposed from experimental and theoretical insights.« less
Wu, Yuntao; Chakoumakos, Bryan C.; Shi, Hongliang; ...
2018-05-14
A self-activated Cs 4YbI 6 single crystal was grown by the vertical Bridgman method. Crystal structure refinements verified the phase purity and the trigonal crystal system with a space group of more » $$\\bar{R}$$3 c. By using differential scanning calorimetry, the melting and crystallization points were determined to be 550 and 510 °C, respectively. Luminescence and scintillation properties were systematically studied. Upon ultraviolet light (360 nm) excitation, the Cs 4YbI 6 crystal exhibits bluish-green emission centered at 450 and 480 nm due to spin-allowed and spin-forbidden transitions of Yb 2+ activators. The lifetimes of the corresponding emission bands at room temperature are tens and hundreds of nanoseconds, respectively. X-ray excited radioluminescence spectrum is dominated by the spin-forbidden transition of Yb 2+ at 480 nm. The absolute light yield is 2700 ± 200 photons/MeV with a principal scintillation decay time of 33 ns. In conclusion, the physical explanation for the low light yield observed is proposed from experimental and theoretical insights.« less
About Small Streams and Shiny Rocks: Macromolecular Crystal Growth in Microfluidics
NASA Technical Reports Server (NTRS)
vanderWoerd, Mark; Ferree, Darren; Spearing, Scott; Monaco, Lisa; Molho, Josh; Spaid, Michael; Brasseur, Mike; Curreri, Peter A. (Technical Monitor)
2002-01-01
We are developing a novel technique with which we have grown diffraction quality protein crystals in very small volumes, utilizing chip-based, microfluidic ("LabChip") technology. With this technology volumes smaller than achievable with any laboratory pipette can be dispensed with high accuracy. We have performed a feasibility study in which we crystallized several proteins with the aid of a LabChip device. The protein crystals are of excellent quality as shown by X-ray diffraction. The advantages of this new technology include improved accuracy of dispensing for small volumes, complete mixing of solution constituents without bubble formation, highly repeatable recipe and growth condition replication, and easy automation of the method. We have designed a first LabChip device specifically for protein crystallization in batch mode and can reliably dispense and mix from a range of solution constituents. We are currently testing this design. Upon completion additional crystallization techniques, such as vapor diffusion and liquid-liquid diffusion will be accommodated. Macromolecular crystallization using microfluidic technology is envisioned as a fully automated system, which will use the 'tele-science' concept of remote operation and will be developed into a research facility aboard the International Space Station.
Growth and spectral properties of Tm:BaY2F8 crystals with different Tm3+ concentration
NASA Astrophysics Data System (ADS)
Liu, Wang; Li, Chun; Xu, Jialin; Zhou, Yao; Xie, Huishuang; Gao, Meiling; Yin, Ru; Zheng, Dongyang; Lin, Hai; Liu, Jinghe; Zeng, Fanming
2016-01-01
Tm3+:BaY2F8 (Tm:BYF) laser crystals with different doping concentrations were successfully grown by Czochralski method. The optimal growth parameters obtained are as follows: the pulling rate is 0.5 mm/h; the rotation speed is 5 rpm; the cooling rate is 10°C/h. Phase composition, absorption spectra, and fluorescence properties of crystals were studied by XRD and spectral methods. XRD analysis indicates that the crystal belongs to monoclinic system with the C2/ m space group. The lattice parameters were calculated and the anisotropy of the crystals was studied, confirming that the a axis is the best growth direction. The absorption peaks around 790 nm became larger with increase of Tm3+ concentration. The cross section of 15% Tm:BYF crystal around 791 nm is 9.47 × 10-21 cm2. The 10% Tm:BYF crystal has the strongest emission peak around 1879.6 nm with the FWHM of 79 nm and the emission cross-section of 2.13 × 10-21 cm2, which is favorable for the 1.88 μm laser output.
NASA's approach to the commercial use of space
NASA Technical Reports Server (NTRS)
Gillam, I. T., IV
1984-01-01
NASA planning activities in the area of commercial development of space resources are reviewed. Examples of specific types of commercial space ventures are given, according to three different categories: new commercial high-technology ventures; new commercial application of existing space technology, and commercial ventures resulting from the transfer of existing space programs to the private sector. Basic objectives for reducing technical, financial and institutional risks for commercial space operations are considered. Attention is given to the cooperative working environment encouraged by Joint Endeavor Agreements (JEAs) and Technical Exchange Agreements (TEAs) between industrial organizations in the development of space systems. Benefits of the commercial development of space resources include the production of purer pharmaceuticals for the treatment of cancers, kidney diseases, and diabetes; and the development of ultra-pure semiconductor crystals for use in next generation electronic equipment.
A study of crystal growth by solution technique
NASA Technical Reports Server (NTRS)
Lal, R. B.
1981-01-01
The mechanism of crystal growth by solution technique was studied. A low temperature solution crystal growth setup was developed. Crystals of triglycine sulfate (TGS) were grown using this arrangement. Some additional tasks were performed toward fabrication of experiments for future space flight.
Holographic data storage crystals for the LDEF
NASA Technical Reports Server (NTRS)
Callen, W. Russell; Gaylord, Thomas K.
1993-01-01
Crystals of lithium niobate were passively exposed to the space environment of the Long Duration Exposure Facility (LDEF). Three of the four crystals contained volume holograms. Although the crystals suffered the surface damage characteristic of that suffered by other components on the Georgia Tech tray, the crystals remained suitable for the formation of volume holograms.
NASA Technical Reports Server (NTRS)
Mckannan, E. C.
1983-01-01
Development of a given technology for national defense and large systems developments when the task is too large or risky for entrepreneurs, yet is clearly in the best interest of the nation are discussed. Advanced research to identify areas of interest was completed. Examples of commercial opportunities are the McDonnell-Douglas Corporation purification process for pharmaceutical products and the Microgravity Research Associates process for growing gallium arsenide crystals in space.
Akter, Mahfuza; Inoue, Chika; Komori, Hirofumi; Matsuda, Nana; Sakurai, Takeshi; Kataoka, Kunishige; Higuchi, Yoshiki; Shibata, Naoki
2016-10-01
Multicopper oxidases oxidize various phenolic and nonphenolic compounds by using molecular oxygen as an electron acceptor to produce water. A multicopper oxidase protein, CueO, from Escherichia coli is involved in copper homeostasis in the bacterial cell. Although X-ray crystallographic studies have been conducted, the reduction mechanism of oxygen and the proton-transfer pathway remain unclear owing to the difficulty in identifying H atoms from X-ray diffraction data alone. To elucidate the reaction mechanism using neutron crystallography, a preparation system for obtaining large, high-quality single crystals of deuterated CueO was developed. Tiny crystals were obtained from the deuterated CueO initially prepared from the original construct. The X-ray crystal structure of the deuterated CueO showed that the protein contained an incompletely truncated signal sequence at the N-terminus, which resulted in the heterogeneity of the protein sample for crystallization. Here, a new CueO expression system that had an HRV3C cleavage site just after the signal sequence was constructed. Deuterated CueO from the new construct was expressed in cells cultured in deuterated algae-extract medium and the signal sequence was completely eliminated by HRV3C protease. The deuteration level of the purified protein was estimated by MALDI-TOF mass spectrometry to be at least 83.2% compared with nondeuterated protein. Nondeuterated CueO crystallized in space group P2 1 , with unit-cell parameters a = 49.51, b = 88.79, c = 53.95 Å, β = 94.24°, and deuterated CueO crystallized in space group P2 1 2 1 2 1 , with unit-cell parameters a = 49.91, b = 106.92, c = 262.89 Å. The crystallographic parameters for the crystals of the new construct were different from those previously reported for nondeuterated crystals. The nondeuterated and deuterated CueO from the new construct had similar UV-Vis spectra, enzymatic activities and overall structure and geometry of the ligands of the Cu atoms in the active site to those of previously reported CueO structures. These results indicate that the CueO protein prepared using the new construct is suitable for further neutron diffraction studies.
NASA Technical Reports Server (NTRS)
Becia, Piotr; Wiegel, Michaela E. K.
2004-01-01
A research carried out under Award Number NAG8-1487 was aimed at to the design, conduct and analysis of experiments directed at the identification and control of gravitational effects on crystal growth, segregation and defect formation in the Sillenite system: bismuth silicate (Bi(12)SiO(20)). Correlation analyses was conducted in order to establish the influence of gravity related defects introduced during crystal growth on critical, application specific properties. Achievement of the states objective was conducted during the period from Feb. 01, 1998 to Dec. 31, 2003 with the following anticipated milestones: 1. Establishment of capabilities for (a) reproducible Czochralski and Bridgman-type growth of BSO single crystals and (b) for comprehensive analysis of crystalline and chemical defects as well as for selective property characterization of grown crystals (year 1). 2. Design and execution of critical space growth experiment(s) based on analyses of prefatory space results (experiments aimed at establishing the viability of planned approaches and procedures) and on unresolved issues related to growth, segregation and defect formation associated with conventional growth in Bridgman geometries. Comparative analysis of growth under conventional and under mu-g conditions; identification of gravity related defect formation during conventional Bridgman growth and formulation of approaches for their control (years 2 and 3). Development of charge confinement system which permits growth interface demarcation (in a mu-g environment) as well as minimization of confinement related stress and contamination during growth; design of complementary mu-g growth experiments aimed at quantitative mu-g growth and segregation analyses (year 4). 3. Conduct of quantitative mu-g growth experiments directed at: (a) identification and control of gravity related crystalline and chemical defect formation during single crystal growth of Bi(12)SiO(20) and at (b) defect engineering -the development of approaches to the controlled generation during crystal growth of specified point defects in homogeneous distribution (year 5). The proposed research places focus on a class of materials which have outstanding electrical and optical properties but have so far failed to reach their potential, primarily because of our inability to control adequately their stoichiometry and crystal defect formation as well as confinement related contamination and lattice stress.
STS-67 Space Shuttle mission report
NASA Technical Reports Server (NTRS)
Fricke, Robert W., Jr.
1995-01-01
The STS-67 Space Shuttle Program Mission Report provides the results of the orbiter vehicle performance evaluation during this sixty-eighth flight of the Shuttle Program, the forty-third flight since the return to flight, and the eighth flight of the Orbiter vehicle Endeavour (OV-105). In addition, the report summarizes the payload activities and the performance of the External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle Main Engines (SSME). The serial numbers of the other elements of the flight vehicle were ET-69 for the ET; 2012, 2033, and 2031 for SSME's 1, 2, and 3, respectively; and Bl-071 for the SRB's. The left-hand RSRM was designated 360W043A, and the right-hand RSRM was designated 360L043B. The primary objective of this flight was to successfully perform the operations of the ultraviolet astronomy (ASTRO-2) payload. Secondary objectives of this flight were to complete the operations of the Protein Crystal Growth - Thermal Enclosure System (PCG-TES), the Protein Crystal Growth - Single Locker Thermal Enclosure System (PCG-STES), the Commercial Materials Dispersion Apparatus ITA Experiments (CMIX), the Shuttle Amateur Radio Experiment-2 (SAREX-2), the Middeck Active Control Experiment (MACE), and two Get-Away Special (GAS) payloads.
First-principles study on structure stabilities of α-S and Na-S battery systems
NASA Astrophysics Data System (ADS)
Momida, Hiroyoshi; Oguchi, Tamio
2014-03-01
To understand microscopic mechanisms of charge and discharge reactions in Na-S batteries, there has been increasing needs to study fundamental atomic and electronic structures of elemental S as well as that of Na-S phases. The most stable form of S is known to be an orthorhombic α-S crystal at ambient temperature and pressure, and α-S consists of puckered S8 rings which crystallize in space group Fddd . In this study, the crystal structure of α-S is examined by using first-principles calculations with and without the van der Waals interaction corrections of Grimme's method, and results clearly show that the van der Waals interactions between the S8 rings have crucial roles on cohesion of α-S. We also study structure stabilities of Na2S, NaS, NaS2, and Na2S5 phases with reported crystal structures. Using calculated total energies of the crystal structure models, we estimate discharge voltages assuming discharge reactions from 2Na+ xS -->Na2Sx, and discharge reactions in Na/S battery systems are discussed by comparing with experimental results. This work was partially supported by Elements Strategy Initiative for Catalysts and Batteries (ESICB) of Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan.
Dual demodulation interferometer with two-wave mixing in GaAs photorefractive crystal
NASA Astrophysics Data System (ADS)
Zhenzhen, Zhang; Zhongqing, Jia; Guangrong, Ji; Qiwu, Wang
2018-07-01
A dual demodulation interferometer with two-wave mixing (TWM) in the GaAs photorefractive crystal (PRC) is proposed and experimentally demonstrated. The GaAs PRC has tiny temperature change under high voltage thus not requiring thermoelectric cooler (TEC) to stabilize the temperature, and adaptive to low frequency fluctuation below 200 Hz. The system is an unbalanced TWM interferometer, which could demodulate the phase change both space variation and wavelength shift induced by strain. Two demodulation modes' formulas are provided in theory respectively. Experimental results have been tested and compared with theoretical analysis, demonstrating that it is a practical and flexible system for detection of mechanical vibration or structure health monitoring (SHM) in engineering by selecting different demodulation mode.
Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber.
Schmidt, Oliver A; Euser, Tijmen G; Russell, Philip St J
2013-12-02
We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems.
Chemical Vapor Deposition Of Silicon Carbide
NASA Technical Reports Server (NTRS)
Powell, J. Anthony; Larkin, David J.; Matus, Lawrence G.; Petit, Jeremy B.
1993-01-01
Large single-crystal SiC boules from which wafers of large area cut now being produced commerically. Availability of wafers opens door for development of SiC semiconductor devices. Recently developed chemical vapor deposition (CVD) process produces thin single-crystal SiC films on SiC wafers. Essential step in sequence of steps used to fabricate semiconductor devices. Further development required for specific devices. Some potential high-temperature applications include sensors and control electronics for advanced turbine engines and automobile engines, power electronics for electromechanical actuators for advanced aircraft and for space power systems, and equipment used in drilling of deep wells. High-frequency applications include communication systems, high-speed computers, and microwave power transistors. High-radiation applications include sensors and controls for nuclear reactors.
Deep Space Detection of Oriented Ice Crystals
NASA Astrophysics Data System (ADS)
Marshak, A.; Varnai, T.; Kostinski, A. B.
2017-12-01
The deep space climate observatory (DSCOVR) spacecraft resides at the first Lagrangian point about one million miles from Earth. A polychromatic imaging camera onboard delivers nearly hourly observations of the entire sun-lit face of the Earth. Many images contain unexpected bright flashes of light over both ocean and land. We constructed a yearlong time series of flash latitudes, scattering angles and oxygen absorption to demonstrate conclusively that the flashes over land are specular reflections off tiny ice crystals floating in the air nearly horizontally. Such deep space detection of tropospheric ice can be used to constrain the likelihood of oriented crystals and their contribution to Earth albedo.
Project Explorer takes its second step: GAS-608 in engineering development
NASA Technical Reports Server (NTRS)
Kitchens, Philip H.
1988-01-01
An a continuation of its Project Explorer series, the Alabama Space and Rocket Center is sponsoring the development of two additional Get Away Special payloads. Details are given of GAS-608, including descriptions of its six experiments in organic crystal growth, roach eggs, yeast, radish seeds, bacterial morphology, and silicon crystals. A brief summary is also presented of GAS-105 and the Space Camp program for stimulating student first hand participation in space flight studies. GAS-608 will carry six student experiments, which will involve biology, crystal growth, and biochemistry in addition to a centralized package for electronics and power supply.
Resonance-enhanced optical forces between coupled photonic crystal slabs.
Liu, Victor; Povinelli, Michelle; Fan, Shanhui
2009-11-23
The behaviors of lateral and normal optical forces between coupled photonic crystal slabs are analyzed. We show that the optical force is periodic with displacement, resulting in stable and unstable equilibrium positions. Moreover, the forces are strongly enhanced by guided resonances of the coupled slabs. Such enhancement is particularly prominent near dark states of the system, and the enhancement effect is strongly dependent on the types of guided resonances involved. These structures lead to enhancement of light-induced pressure over larger areas, in a configuration that is directly accessible to externally incident, free-space optical beams.
NASA Astrophysics Data System (ADS)
Arnold, Thorsten; Siegmund, Marc; Pankratov, Oleg
2011-08-01
We apply exact-exchange spin-density functional theory in the Krieger-Li-Iafrate approximation to interacting electrons in quantum rings of different widths. The rings are threaded by a magnetic flux that induces a persistent current. A weak space and spin symmetry breaking potential is introduced to allow for localized solutions. As the electron-electron interaction strength described by the dimensionless parameter rS is increased, we observe—at a fixed spin magnetic moment—the subsequent transition of both spin sub-systems from the Fermi liquid to the Wigner crystal state. A dramatic signature of Wigner crystallization is that the persistent current drops sharply with increasing rS. We observe simultaneously the emergence of pronounced oscillations in the spin-resolved densities and in the electron localization functions indicating a spatial electron localization showing ferrimagnetic order after both spin sub-systems have undergone the Wigner crystallization. The critical rSc at the transition point is substantially smaller than in a fully spin-polarized system and decreases further with decreasing ring width. Relaxing the constraint of a fixed spin magnetic moment, we find that on increasing rS the stable phase changes from an unpolarized Fermi liquid to an antiferromagnetic Wigner crystal and finally to a fully polarized Fermi liquid.
Arnold, Thorsten; Siegmund, Marc; Pankratov, Oleg
2011-08-24
We apply exact-exchange spin-density functional theory in the Krieger-Li-Iafrate approximation to interacting electrons in quantum rings of different widths. The rings are threaded by a magnetic flux that induces a persistent current. A weak space and spin symmetry breaking potential is introduced to allow for localized solutions. As the electron-electron interaction strength described by the dimensionless parameter r(S) is increased, we observe-at a fixed spin magnetic moment-the subsequent transition of both spin sub-systems from the Fermi liquid to the Wigner crystal state. A dramatic signature of Wigner crystallization is that the persistent current drops sharply with increasing r(S). We observe simultaneously the emergence of pronounced oscillations in the spin-resolved densities and in the electron localization functions indicating a spatial electron localization showing ferrimagnetic order after both spin sub-systems have undergone the Wigner crystallization. The critical r(S)(c) at the transition point is substantially smaller than in a fully spin-polarized system and decreases further with decreasing ring width. Relaxing the constraint of a fixed spin magnetic moment, we find that on increasing r(S) the stable phase changes from an unpolarized Fermi liquid to an antiferromagnetic Wigner crystal and finally to a fully polarized Fermi liquid. © 2011 IOP Publishing Ltd
Fretting Stresses in Single Crystal Superalloy Turbine Blade Attachments
NASA Technical Reports Server (NTRS)
Arakere, Nagaraj K.; Swanson, Gregory
2000-01-01
Single crystal nickel base superalloy turbine blades are being utilized in rocket engine turbopumps and turbine engines because of their superior creep, stress rupture, melt resistance and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the most widely used single crystal nickel base turbine blade superalloys are PWA 1480/1493 and PWA 1484. These alloys play an important role in commercial, military and space propulsion systems. High Cycle Fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Blade attachment regions are prone to fretting fatigue failures. Single crystal nickel base superalloy turbine blades are especially prone to fretting damage because the subsurface shear stresses induced by fretting action at the attachment regions can result in crystallographic initiation and crack growth along octahedral planes. Furthermore, crystallographic crack growth on octahedral planes under fretting induced mixed mode loading can be an order of magnitude faster than under pure mode I loading. This paper presents contact stress evaluation in the attachment region for single crystal turbine blades used in the NASA alternate Advanced High Pressure Fuel Turbo Pump (HPFTP/AT) for the Space Shuttle Main Engine (SSME). Single crystal materials have highly orthotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. Blades and the attachment region are modeled using a large-scale 3D finite element (FE) model capable of accounting for contact friction, material orthotrophy, and variation in primary and secondary crystal orientation. Contact stress analysis in the blade attachment regions is presented as a function of coefficient of friction and primary and secondary crystal orientation, Stress results are used to discuss fretting fatigue failure analysis of SSME blades. Attachment stresses are seen to reach peak values at locations where fretting cracks have been observed. Fretting stresses at the attachment region are seen to vary significantly as a function of crystal orientation. Attempts to adapt techniques used for estimating fatigue life in the airfoil region, for life calculations in the attachment region, are presented. An effective model for predicting crystallographic crack initiation under mixed mode loading is required for life prediction under fretting action.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Galeša, Katja; Brzin, Jože; Sabotič, Jerica
2006-01-01
Clitocypin is a cysteine protease inhibitor from the mushroom Clitocybe nebularis. The protein has been purified from natural sources and crystallized in a variety of non-isomorphous forms belonging to monoclinic and triclinic space groups. Clitocypin is a cysteine protease inhibitor from the mushroom Clitocybe nebularis. The protein has been purified from natural sources and crystallized in a variety of non-isomorphous forms belonging to monoclinic and triclinic space groups. A diffraction data set to 1.55 Å resolution was obtained from a crystal belonging to space group P2, with unit-cell parameters a = 38.326, b = 33.597, c = 55.568 Å, βmore » = 104°. An inability to achieve isomorphism forced the use of MAD and SAD phasing methods. Phasing is in progress.« less
Macromolecular Crystallization in Microfluidics for the International Space Station
NASA Technical Reports Server (NTRS)
Monaco, Lisa A.; Spearing, Scott
2003-01-01
At NASA's Marshall Space Flight Center, the Iterative Biological Crystallization (IBC) project has begun development on scientific hardware for macromolecular crystallization on the International Space Station (ISS). Currently ISS crystallization research is limited to solution recipes that were prepared on the ground prior to launch. The proposed hardware will conduct solution mixing and dispensing on board the ISS, be fully automated, and have imaging functions via remote commanding from the ground. Utilizing microfluidic technology, IBC will allow for on orbit iterations. The microfluidics LabChip(R) devices that have been developed, along with Caliper Technologies, will greatly benefit researchers by allowing for precise fluid handling of nano/pico liter sized volumes. IBC will maximize the amount of science return by utilizing the microfluidic approach and be a valuable tool to structural biologists investigating medically relevant projects.
Senda, Miki; Hatta, Takashi; Kimbara, Kazuhide; Senda, Toshiya
2010-01-01
A thermostable manganese(II)-dependent 2,3-dihydroxybiphenyl-1,2-dioxygenase derived from Bacillus sp. JF8 was crystallized. The initial screening for crystallization was performed by the sitting-drop vapour-diffusion method using a crystallization robot, resulting in the growth of two crystal forms. The first crystal belonged to space group P1, with unit-cell parameters a = 62.7, b = 71.4, c = 93.6 Å, α = 71.2, β = 81.0, γ = 64.0°, and diffracted to 1.3 Å resolution. The second crystal belonged to space group I222, with unit-cell parameters a = 74.2, b = 90.8, c = 104.3 Å, and diffracted to 1.3 Å resolution. Molecular-replacement trials using homoprotocatechuate 2,3-dioxygenase from Arthrobacter globiformis (28% amino-acid sequence identity) as a search model provided a satisfactory solution for both crystal forms. PMID:20208161
Free Energy Calculations of Crystalline Hard Sphere Complexes Using Density Functional Theory
Gunawardana, K. G.S.H.; Song, Xueyu
2014-12-22
Recently developed fundamental measure density functional theory (FMT) is used to study binary hard sphere (HS) complexes in crystalline phases. By comparing the excess free energy, pressure and phase diagram, we show that the fundamental measure functional yields good agreements to the available simulation results of AB, AB 2 and AB 13 crystals. Additionally, we use this functional to study the HS models of five binary crystals, Cu 5Zr(C15 b), Cu 51Zr 14(β), Cu 10Zr 7(φ), CuZr(B2) and CuZr 2 (C11 b), which are observed in the Cu-Zr system. The FMT functional gives well behaved minimum for most of themore » hard sphere crystal complexes in the two dimensional Gaussian space, namely a crystalline phase. However, the current version of FMT functional (white Bear) fails to give a stable minimum for the structure Cu 10Zr 7(φ). We argue that the observed solid phases for the HS models of the Cu-Zr system are true thermodynamic stable phases and can be used as a reference system in perturbation calculations.« less
Shakila, K; Kalainathan, S
2015-01-25
In this paper, we report the successful growth of complex compound of zinc iodide with thiocarbamide by slow evaporation method. The single crystal XRD study reveals that the crystal belongs to monoclinic system with centrosymmetric space group and powder XRD analysis shows that the perfect crystalline nature of the crystal. The presence of functional group and element were confirmed from FT-IR and EDAX analysis. Optical absorbance of the grown crystal was studied by UV-Vis spectrophotometer. The optical constants were calculated from the optical absorbance data such as refractive index (n), extinction coefficient (K) and reflectance (R). The optical band gap (Eg) of thiocarbamide zinc iodide crystal is 4.22 eV. The magnetic properties of grown crystal have been determined by Vibrating Sample Magnetometry (VSM). Room temperature magnetization revealed a ferromagnetic behaviour for the grown crystal. The antibacterial and antifungal activities of the title compound were performed by well diffusion method and MIC method against the standard bacteria like Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and against fungus like Aspergillus niger, Rhizopus sps and Penicillium sps. Thermal behaviour of the crystal has been investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Copyright © 2014. Published by Elsevier B.V.
Growth and characterization of Melaminium bis (trichloroacetate) dihydrate
NASA Astrophysics Data System (ADS)
Kanagathara, N.; Renganathan, N. G.; Marchewka, M. K.; Sivakumar, N.; Gayathri, K.; Krishnan, P.; Gunasekaran, S.; Anbalagan, G.
2013-01-01
Single crystals of melaminium bis (trichloroacetate) dihydrate have been grown successfully by slow evaporation solution growth technique at room temperature. Single crystal X-ray diffraction analysis reveals that the compound crystallizes in monoclinic system with non -centrosymmetric space group C2 with lattice parameters a = 17.70 Å, b = 8.44 Å, c = 6.09 Å, α = 90°, β = 100.24°, γ = 90° and V = 900 (Å)3. The UV-Vis transmittance spectrum shows that the crystal has a good optical transmittance in the entire visible region with lower cutoff wavelength of 351 nm. The vibrational frequencies of various functional groups present in the crystal have been derived from FI-IR, FT-Raman and Confocal Raman analyses. The chemical structure of the compound was established by 1H and 13C NMR spectrum. TGA-DTA analysis reveals that the materials have good thermal stability and the melting point of the crystal is found to be 195 °C. The dielectric response of the crystals was studied in the frequency range 50 Hz to 5 MHz at different temperatures and the results are discussed. Etching studies show the growth pattern of the crystals. The second harmonic generation efficiency was measured in comparison with KDP by employing powder Kurtz method.
Thermophotovoltaic power conversion systems: Current performance and future potential
Celanovic, Ivan; Bermel, Peter; Soljacic, Marin
2011-01-01
Thermophotovoltaic (TPV) systems offer a unique, solid-state approach to converting heat into electricity based on thermal radiation. TPV is particularly suitable for certain classes of power generation applications that are not well served by standard engines, such as long, remote missions where repairs are difficult, and portable generation where space and weight are at a premium. While standard thermophotovoltaics are limited in their conversion efficiency, photonic crystals can improve performance by an order of magnitude for a number of systems. While there are many potential applications, two exemplary systems are discussed: TPV μreactors for portable power generation in a mm-scalemore » form factor, and solar TPV for long-term off-grid power generation from sunlight. In both cases, photonic crystals can enable potential performance exceeding that of many other well-known technologies, such as single-junction photovoltaics.« less
Development of a tunable filter for coronal polarimetry
NASA Astrophysics Data System (ADS)
Tomczyk, S.; Mathew, S. K.; Gallagher, D.
2016-07-01
Measuring magnetic fields in the solar corona is crucial to understanding and predicting the Sun's generation of space weather that affects communications, GPS systems, space flight, and power transmission. The Coronal Solar Magnetism Observatory Large Coronagraph (COSMO LC) is a proposed 1.5 m aperture coronagraph designed to synoptically observe magnetic fields and plasma properties in the large-scale corona to improve our understanding of solar processes that cause space weather. The LC will observe coronal emission lines over the wavelength range from 500 to 1100 nm with a field of view of 1° and a spatial resolution of 2 arcsec. A spectral resolution greater than 8000 over the wavelength range is needed to resolve the polarization signatures of magnetic fields in the emission line profiles. The aperture and field of view of the LC set an étendue requirement of 1.39 m2 deg2 for the postfocus instrumentation. We find that a tunable wide-field birefringent filter using Lithium Niobate crystals can meet the étendue and spectral resolution requirements for the LC spectrometer. We have tested a number of commercially available crystals and verify that crystals of the required size and birefringence uniformity are available. We also evaluate electro-optical tuning of a Lithium Niobate birefringent filter by the application of high voltage. This tunable filter represents a key enabling technology for the COSMO LC.
Solidification of eutectic system alloys in space (M-19)
NASA Technical Reports Server (NTRS)
Ohno, Atsumi
1993-01-01
It is well known that in the liquid state eutectic alloys are theoretically homogeneous under 1 g conditions. However, the homogeneous solidified structure of this alloy is not obtained because thermal convection and non-equilibrium solidification occur. The present investigators have clarified the solidification mechanisms of the eutectic system alloys under 1 g conditions by using the in situ observation method; in particular, the primary crystals of the eutectic system alloys never nucleated in the liquid, but instead did so on the mold wall, and the crystals separated from the mold wall by fluid motion caused by thermal convection. They also found that the equiaxed eutectic grains (eutectic cells) are formed on the primary crystals. In this case, the leading phase of the eutectic must agree with the phase of the primary crystals. In space, no thermal convection occurs so that primary crystals should not move from the mold wall and should not appear inside the solidified structure. Therefore no equiaxed eutectic grains will be formed under microgravity conditions. Past space experiments concerning eutectic alloys were classified into two types of experiments: one with respect to the solidification mechanisms of the eutectic alloys and the other to the unidirectional solidification of this alloy. The former type of experiment has the problem that the solidified structures between microgravity and 1 g conditions show little difference. This is why the flight samples were prepared by the ordinary cast techniques on Earth. Therefore it is impossible to ascertain whether or not the nucleation and growth of primary crystals in the melt occur and if primary crystals influence the formation of the equiaxed eutectic grains. In this experiment, hypo- and hyper-eutectic aluminum copper alloys which are near eutectic point are used. The chemical compositions of the samples are Al-32.4mass%Cu (Hypo-eutectic) and Al-33.5mass%Cu (hyper-eutectic). Long rods for the samples are cast by the Ohno Continuous Casting Process and they show the unidirectionally solidified structure. Each flight and ground sample was made of these same rods. The dimensions of all samples are 4.5 mm in diameter and 23.5 mm in length. Each sample is put in a graphite capsule and then vacuum sealed in a double silica ampoule. Then the ampoule is put in the tantalum cartridge and sealed by electron beam welding. For onbard experiments, a Continuous Heating Furnance (CHF) will be used for melting and solidifying samples under microgravity conditions. Six flight samples will be used. Four samples are hypo-eutectic and two are hyper-eutectic alloys. The surface of the two hypo-eutectic alloy samples are covered with aluminum oxide film to prevent Marangoni convection expected under microgravity conditions. Each sample will be heated to 700 C and held at that temperature for 5 min. After that the samples will be allowed to cool to 500 C in the furnace and they will be taken out of the furnace for He gas cooling. The heating and cooling diagrams for the flight experiments are shown. After collecting the flight samples, the solidified structures of the samples will be examined and the mechanisms of eutectic solidification under microgravity conditions will be determined. It is likely that successful flight experiment results will lead to production of high quality eutectic alloys and eutectic composite materials in space.
Zaluzhnyy, I A; Kurta, R P; Menushenkov, A P; Ostrovskii, B I; Vartanyants, I A
2016-09-01
An x-ray scattering approach to determine the two-dimensional (2D) pair distribution function (PDF) in partially ordered 2D systems is proposed. We derive relations between the structure factor and PDF that enable quantitative studies of positional and bond-orientational (BO) order in real space. We apply this approach in the x-ray study of a liquid crystal (LC) film undergoing the smectic-A-hexatic-B phase transition, to analyze the interplay between the positional and BO order during the temperature evolution of the LC film. We analyze the positional correlation length in different directions in real space.
NASA Astrophysics Data System (ADS)
Karadeniz, Şeyma; Ataol, Cigdem Yuksektepe; Şahin, Onur; İdil, Önder; Bati, Hümeyra
2018-06-01
A new aroylhydrazoneoxime, N'-((2Z, 3E)-3-(hydroxyimino)butan-2-ylidene)-2-phenylacetohydrazide ligand (LH2) and its Ni(II) and Co(II) complexes, have been synthesized and characterized by elemental and thermal analyses, IR and UV-vis spectroscopy, magnetic moment and X-ray diffraction. The antimicrobial activities of these compounds were tested by using minimal inhibitory concentration method (MIC). The ligand-containing aroylhydrazone and oxime groups and its Ni complex crystallize in the triclinic system and P 1 - space group, while its Co complex crystallizes in the monoclinic system and the C 2/c space group. X-ray results show that the ligand in the keto form is transformed into enolic form when it forms coordination. From elemental analysis data, the stoichiometry of Co(II) complex was found to be 1:2 (metal/ligand), but 1:1 for Ni(II). IR spectra indicate that the ligand acts as monoanionic NNO- tridentate and coordination takes place form through the oxime nitrogen, imine nitrogen, and enolate oxygen atoms.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aoki, Ken-ichi; Tanaka, Nobutada, E-mail: ntanaka@pharm.showa-u.ac.jp; Ishikura, Shuhei
Pig heart carbonyl reductase has been crystallized in the presence of NADPH. Diffraction data have been collected using synchrotron radiation. Pig heart carbonyl reductase (PHCR), which belongs to the short-chain dehydrogenase/reductase (SDR) family, has been crystallized by the hanging-drop vapour-diffusion method. Two crystal forms (I and II) have been obtained in the presence of NADPH. Form I crystals belong to the tetragonal space group P4{sub 2}, with unit-cell parameters a = b = 109.61, c = 94.31 Å, and diffract to 1.5 Å resolution. Form II crystals belong to the tetragonal space group P4{sub 1}2{sub 1}2, with unit-cell parameters amore » = b = 120.10, c = 147.00 Å, and diffract to 2.2 Å resolution. Both crystal forms are suitable for X-ray structure analysis at high resolution.« less
Piezoelectric and Semiconducting Ribbon for Flexible Energy Harvesting
2012-06-08
ES) 10. SPONSOR/MONITOR’S ACRONYM(S) Space and Naval Warfare Systems Command SPA WAR 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION...rubbers could yield breakthroughs in implantable or wearable energy harvesting systems . Being electromechanically coupled, piezoelectric crystals...ctuator d33 (pm/V) PZT PVDF Quartz Bone PZT > 80% Conversion Efficiency 3333 dk VdE 2233 Energy 250 25 2.5
NASA Astrophysics Data System (ADS)
Skachkov, Dmitry; van Schilfgaarde, Mark; Lambrecht, Walter
The full-potential linearized muffin-tin orbital method allows for a real space representation of the GW or quasi-particle self-consistent (QS)GW self-energy ΣR , L ; R' + T , L'. This can be used to construct the self-energy matrix for a point defect system in a large supercell from that of the perfect crystal in the primitive cell and the self-energy of the defect site and its near neighborhood, obtained self-consistently in a smaller supercell. At the interface between both regions we can average the two types of ΣR , L ; R' + T , L' matrix blocks. The result relies on the limited range of the self-energy matrix in real space. It means that we can calculate the quasiparticle energy levels of the defect system at essentially the cost of a DFT calculation and a few QSGW calculations for relatively small systems. The approach presently focuses on quasiparticle energy levels of band structures of the defect system rather than total energies. We will present test results for AsGa\\ in GaAs, ZnGe in ZnGeN2, NO, VO, VZn, and NO - VZn in ZnO. Supported by the US-DOE-BES under Grant No. DE-SC0008933.
NASA Technical Reports Server (NTRS)
2004-01-01
To the crystallographer, this may not be a diamond but it is just as priceless. A Lysozyme crystal grown in orbit looks great under a microscope, but the real test is X-ray crystallography. The colors are caused by polarizing filters. Proteins can form crystals generated by rows and columns of molecules that form up like soldiers on a parade ground. Shining X-rays through a crystal will produce a pattern of dots that can be decoded to reveal the arrangement of the atoms in the molecules making up the crystal. Like the troops in formation, uniformity and order are everything in X-ray crystallography. X-rays have much shorter wavelengths than visible light, so the best looking crystals under the microscope won't necessarily pass muster under the X-rays. In order to have crystals to use for X-ray diffraction studies, crystals need to be fairly large and well ordered. Scientists also need lots of crystals since exposure to air, the process of X-raying them, and other factors destroy them. Growing protein crystals in space has yielded striking results. Lysozyme's structure is well known and it has become a standard in many crystallization studies on Earth and in space.
Space, our next frontier; Proceedings of the conference, Dallas, TX, June 7, 8, 1984
DOE Office of Scientific and Technical Information (OSTI.GOV)
Musgrave, G.
1985-01-01
The present conference on space development encompasses space commercialization, legislative, legal, and insurance-related factors in current space programs, political aspects of space militarization and governmental control, the military future uses of space and their consequences, command and control issues arising in space, economic influences on space policy, and recent developments in space solar power generation concepts. Attention is given to public opinion surveys concerning the scientific, military, and economic uses of space, the Leasecraft orbital industrial infrastructure concept, capitalism and democracy in space development, the current status of space law on commercialization topics, the nature of Ballistic Missile Defense, themore » Soviet Space threat, the High Frontier concept for space defense, lunar solar power systems, solar power satellites, and the utilization of lunar resources for the reduction of lunar base construction costs. Such specific technical issues as microgravity crystal growth and directional solidification, electrophoresis operations for pharmaceuticals, and technical barriers to commercial access to space, are also noted.« less
Unusual structural phase transition in [N(C2H5)4][N(CH3)4][ZnBr4
NASA Astrophysics Data System (ADS)
Krawczyk, Monika K.; Ingram, Adam; Cach, Ryszard; Czapla, Zbigniew; Czupiński, Olaf; Dacko, Sławomir; Staniorowski, Piotr
2018-04-01
The new hybrid organic-inorganic crystal [N(C2H5)4][N(CH3)4][ZnBr4] was grown and its physical properties and structural phase transition are presented. On the basis of thermal analysis (DSC (differential scanning calorimetry), DTA (differential thermal analysis), DTG), X-ray structural, dilatometric and dielectric studies as well as optical observation, the reversible first-order phase transition at 490/488 K on heating and cooling run, respectively, has been found. An appearance of domain structure of ferroelastic type gives evidence for an untypical lowering of crystal symmetry during the phase transition. At room temperature, the satisfying crystal structure solution was found in the tetragonal system, in the P?21m space group.