Journal articles on the topic 'Crystals'
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1
Zhang, Fei Hu, Shao Long Guo, Yong Zhang, and Dian Rong Luan. "Research on the Material Removal Mechanism in Deliquescent Polishing of KDP Crystals." Key Engineering Materials 416 (September 2009): 487–91. http://dx.doi.org/10.4028/www.scientific.net/kem.416.487.
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A new ultraprecision machining technology for KDP crystals, deliquescent polishing technology for KDP crystals, is presented. On the basis of analyzing the definitions of deliquescence, the dissolution experiment of KDP crystal’s surface was conducted. Through the experiment, the material removal mechanism in deliquescent polishing of KDP crystals is proposed, and the deliquescent polishing device for KDP crystals is described. Based on the material removal mechanism in deliquescent polishing of KDP crystals, the deliquescent polishing experiment of KDP crystal was carried out, the experimental result has verified the validity, feasibility and effectiveness of the material removal mechanism.
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Sathishkumar, G., M. Lenin, T. Gubendiran, B. Sathiyamoorthy, S. Nithiyanantham, and P. Ramasamy. "Structural, electrical and optical studies on organic NLO single crystal of N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA)." Vietnam Journal of Chemistry 61, no. 6 (December 2023): 778–87. http://dx.doi.org/10.1002/vjch.202300129.
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AbstractThe 2‐methyl‐4‐nitroaniline (NA) was converted into the raw material N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA), and the solubility of BNA in various organic solvents was calculated gravimetrically. BNA's solubility and crystal structure make it an excellent solvent for the low‐temperature solution growth method used to create single crystals of BNA with orthorhombic structure studied through single crystal analysis. Methanol was used to harvest the 3×10 mm3 BNA single crystals, which are big, translucent yellow crystals. BNA, the subject compound, the exothermic and endothermic nature was characterised by TG analyses, differential scanning calorimeter (DSC), functional studies by infrared (IR) spectra, NMR spectral and optical transmission studies. An Nd:YAG laser (1064 nm) was used to observe the second harmonic generation (SHG) of grown crystal leads about 3 times more than KDP crystal. Possible polarization for various temperatures, the crystal's dielectric properties was measured as a function of frequency. Larger surface morphology with high optical to wave conversion efficiency and the results were reviewed. Responding to electric field to leads to liquid crystal display and THz purposes.
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Nelson, J. "Growth-deviation model to understand the perceived variety of falling snow." Atmospheric Chemistry and Physics Discussions 8, no. 2 (March 4, 2008): 4407–37. http://dx.doi.org/10.5194/acpd-8-4407-2008.
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Abstract. What is the source of snow-crystal variety? This question is answered using a model of snow-crystal growth in a cloud. In the model, crystals start under various initial cloud-crystal conditions, and then encounter growth perturbations from random air-temperature deviations along simple crystal trajectories. To obtain distributions of these deviations, I analyzed recent high-resolution measurements of cloud updrafts and temperatures. The trajectories and distributions are used to estimate the number of possible snow crystal shapes, to a given viewing resolution, from a range of initial conditions. The logarithm of this number, defined here as the perceived shape variety or "diversity", is dominated not by the range of conditions, but rather by the air-temperature deviations along a trajectory. This qualitative result is independent of the viewing resolution. Thus, temperature deviations are the main source of crystal diversity. When plotted against the crystal's initial temperature (here –11 to –19°C), the curve is mitten-shaped, with a main peak at –15.4°C and a smaller, sharper peak near –14.4°C. The mitten shape arises from temperature trends in the crystal's terminal fallspeed and prism-face growth rate. Specifically, the two diversity peaks are due to maxima in growth-rate sensitivity to temperature near –15.4 and –14.0°C. Applying the results to all snow crystals ever formed, then, to 1-μm resolution, all crystals that began near –15°C would appear unique, but some that began near –11°C would not.
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McPherson, Alexander. "pH and Redox Induced Color Changes in Protein Crystals Suffused with Dyes." Crystals 9, no. 3 (March 1, 2019): 126. http://dx.doi.org/10.3390/cryst9030126.
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Protein crystals, otherwise usually colorless, can be stained a variety of hues by saturating them with dyes, by diffusion from the mother liquor or co-crystallization. The colors assumed by dyes are a function of chemical factors, particularly pH and redox potential. Protein crystals saturated with a pH sensitive dye, initially at one pH, can be exposed to the mother liquor at a second pH and the crystal will change color over time as H3O+ ions diffuse through the crystal. This allows diffusion rates of H3O+ through the crystal to be measured. Diffusion fronts are often clearly delineated. Similar experiments can be carried out with redox sensitive dyes by adding reductants, such as ascorbic acid or dithionite, or oxidants such as H2O2, to the crystal’s mother liquor. Presented here are a number of experiments using pH or redox sensitive dye-saturated protein crystals, and some experiments using double dye, sequential redox–pH changes.
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Gunter, Mickey E., and F. Donald Bloss. "The spindle stage: A powerful optical tool." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 52–53. http://dx.doi.org/10.1017/s0424820100102341.
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A single, reasonably homogeneous, nonopaque 30-to-300 μm crystal, mounted on a spindle stage and studied by immersion methods under a polarizing microscope, yields optical data frequently sufficient to identify and characterize a substance unequivocally. The data obtainable include (1) the orientation of the crystal's principal vibration axes and (2) its principal refractive indices, to within 0.0002 if desired, for light vibrating along these principal vibration axes. Spindle stages tend to be simple and relatively inexpensive, some costing less than $50. They permit rotation of the crystal about a single axis which is parallel to the microscope stage. This spindle or S-axis is thus perpendicular to the M-axis, namely the microscope stage's axis of rotation.A spindle stage excels when studying anisotropic crystals. It orients uniaxial crystals within minutes and biaxial crystals almost as quickly so that their principal refractive indices - ɛ and ω (uniaxial); α, β and γ (biaxial) - can be determined without significant error from crystal misorientation.
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Senthamizhan, A., K. Sambathkumar, S. Nithiyanantham, and A. A. Alagiriswamy. "Electrical, Optical, Structural Properties with Some Physico-Mechanical of Pure and La3+ Doped L-Alanine Acetate Single Crystals." Sensor Letters 18, no. 12 (December 1, 2020): 894–99. http://dx.doi.org/10.1166/sl.2020.4307.
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Slow evaporation was used to successfully generate single crystals of pure and La3+ doped L-alanine acetate from aqueous solution. The structural, vibrational, chemical analysis carried out through XRD, UV, FTIR with FTRaman Analysis. The Nd: YAG laser was used to confirm and estimate the sample’s Second Harmonic Generation (SHG). The growing crystal’s laser damage threshold was also discovered. Thermogravimetic (TG) and Differential theromogravimetric (DTA) studies were used to measure the thermal stability of the formed crystal. The generated LAlA crystals were also subjected to dielectric and photoconductivity tests. The dopant has boosted the efficiency of the L-alanine acetate crystal, according to nonlinear optical studies.
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Zhong, Z., M. Hasnah, A. Broadbent, E. Dooryhee, and M. Lucas. "Phase-space matching between bent Laue and flat Bragg crystals." Journal of Synchrotron Radiation 26, no. 6 (October 23, 2019): 1917–23. http://dx.doi.org/10.1107/s1600577519010774.
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Through phase-space analysis of Dumond diagrams for a flat Bragg crystal, a single bent Laue crystal and a monochromator consisting of double-bent Laue crystals, this work shows that it is possible to match the flat Bragg crystal to both the single-crystal and double-crystal Laue monochromators. The matched system has the advantage that the phase space of the bent crystal's output beam is much larger than that of the flat crystal, making the combined system stable. Here it is suggested that such a matched system can be used at synchrotron facilities to realize X-ray dark-field imaging, analyzer-based imaging and diffraction-enhanced imaging at beamlines using double-Laue monochromators.
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Polino, M., H. S. Rho, M. P. Pina, R. Mallada, A. L. Carvalho, M. J. Romão, Isabel Coelhoso, J. G. E. Gardeniers, J. G. Crespo, and Carla A. M. Portugal. "Protein Crystallization in a Microfluidic Contactor with Nafion®117 Membranes." Membranes 11, no. 8 (July 21, 2021): 549. http://dx.doi.org/10.3390/membranes11080549.
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Protein crystallization still remains mostly an empirical science, as the production of crystals with the required quality for X-ray analysis is dependent on the intensive screening of the best protein crystallization and crystal’s derivatization conditions. Herein, this demanding step was addressed by the development of a high-throughput and low-budget microfluidic platform consisting of an ion exchange membrane (117 Nafion® membrane) sandwiched between a channel layer (stripping phase compartment) and a wells layer (feed phase compartment) forming 75 independent micro-contactors. This microfluidic device allows for a simultaneous and independent screening of multiple protein crystallization and crystal derivatization conditions, using Hen Egg White Lysozyme (HEWL) as the model protein and Hg2+ as the derivatizing agent. This microdevice offers well-regulated crystallization and subsequent crystal derivatization processes based on the controlled transport of water and ions provided by the 117 Nafion® membrane. Diffusion coefficients of water and the derivatizing agent (Hg2+) were evaluated, showing the positive influence of the protein drop volume on the number of crystals and crystal size. This microfluidic system allowed for crystals with good structural stability and high X-ray diffraction quality and, thus, it is regarded as an efficient tool that may contribute to the enhancement of the proteins’ crystals structural resolution.
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Matko, Vojko, and Miro Milanovič. "Detection Principles of Temperature Compensated Oscillators with Reactance Influence on Piezoelectric Resonator." Sensors 20, no. 3 (February 1, 2020): 802. http://dx.doi.org/10.3390/s20030802.
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This review presents various ways of detection of different physical quantities based on the frequency change of oscillators using piezoelectric crystals. These are influenced by the reactance changes modifying their electrical characteristics. Reactance in series, in parallel, or a combination of reactances can impact the electrical crystal substitute model by influencing its resonant oscillation frequency. In this way, various physical quantities near resonance can be detected with great sensitivity through a small change of capacitance or inductance. A piezoelectric crystal impedance circle and the mode of frequency changing around the resonant frequency change are shown. This review also presents the influence of reactance on the piezoelectric crystal, the way in which the capacitance lost among the crystal’s electrodes is compensated, and how the mode of oscillators’ output frequency is converted to lower frequency range (1–100 kHz). Finally, the review also explains the temperature–frequency compensation of the crystals’ characteristics in oscillators that use temperature–frequency pair of crystals and the procedure of the compensation of crystals own temperature characteristics based on the method switching between the active and reference reactance. For the latter, the experimental results of the oscillator’s output frequency stability (fout = ±0.002 ppm) at dynamical change of environment temperature (0–50 °C) are shown.
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Shtukenberg, Alexander, and Bart Kahr. "Twisted crystals." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C229. http://dx.doi.org/10.1107/s2053273314097708.
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Modern reviews on crystal growth and defects in crystals overlook the fact that a significant portion of materials can spontaneously grow as single crystals with twisted and bent morphologies and curved crystal lattices. Twisted crystals can be found among all types of materials (molecular crystals, salts, minerals, high polymers, metals, and elements) crystallizing in any point and space group from all types of growth media (vapor, solution, gel, glass, melt, and solid state). Their size spans over more than six orders of magnitude ranging from nm where 3D character is equivocal, to cm or dm (some of the biggest natural crystals). Here are illustrated most important features of twisted crystals as well as an analysis of mechanisms that are responsible for this mysterious phenomenon [1]. In general, formation of a twisted crystal is a complex phenomenon involving with certain requirements for dissymmetry, isomorphism, and crystal chemistry. Also critical are processes at the crystal-medium interface as well as the elasticity and plasticity of the crystalline medium. As such, twisting is strongly controlled by morphology and symmetry of the growth face. It frequently requires impurities, sometimes in extremely low concentrations. The intensity of deformation is inversely proportional to the crystal size. The phenomenon is more common when the driving force for crystallization and the temperature are high. Several mechanisms have been proposed to explain the formation of unusual curved morphologies: axial dislocation in whiskers (Eshelby twist); surface stress in polymer lamellae; surface charge and spontaneous polarization in nanoribbons; inhomogeneous fields forming around a growing crystal; and internal stress created by an inhomogeneous impurity distribution. However, most of the mechanisms proposed are insufficiently developed and need further verification and elaboration. The work was supported by the US National Science Foundation and New York University.
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Qin, L. C. "HREM of electron-irradiated silicas." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 1102–3. http://dx.doi.org/10.1017/s0424820100151349.
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Silica (SiO2) crystals exist in various polymorphs which have different densities and different crystal structures, such as quartz, tridymite, and cristobalite, though all of these have in common the network structure which is formed by corner-sharing of SiO4 tetranedra. All these structures are sensitive to electron irradiation. Amorphization occurs when they are irradiated by energetic electrons.In the present study three polymorphs of silica crystals, α-quartz, α-tridymite and α-cristobalite crystals2 were used as starting materials. Electron irradiation experiments were carried out in situ in the electron microscope. The structural changes of the specimens were monitored using high-resolution electron microscopy (HREM).The amorphization of α-quartz crystals was found to progress through two morphologies: (a) nucleation and growth of amorphous nuclei with a sharp boundary with the crystalline matrix (figure 1); and (b) crystallinity lost gradually and more uniformly. Figure 2 shows a series of HREM images showing the amorphization of a tridymite crystal.
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Wang, Zhifeng, Yuquan Gan, Qianqian Du, Shuhong Li, Yunlong Liu, and Wenjun Wang. "Morphology-Dependent Optoelectronic Properties of Pentacene Nanoribbon and Nanosheet Crystallite." Materials 16, no. 2 (January 6, 2023): 557. http://dx.doi.org/10.3390/ma16020557.
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Organic, single crystals have emerged as unique optoelectrical materials due to their highly ordered structure and low defects. In this work, pentacene nanoribbons and nanosheets were selectively fabricated by controlling their growth temperature. The results show that their photoluminescence (PL) activity and electrical properties were strongly dependent on their geometrical morphology and molecular stacking mode such as the degree of π-orbital overlap and intermolecular interaction. The pentacene nanoribbon crystal exhibited a higher PL intensity compared with the nanosheet configuration; conversely, its electrical conductivity was poor. The low-temperature PL measurement indicated that there are stronger π–π stacking interactions in the nanosheet crystal than in the nanoribbon crystal, leading to exciton quenching and higher conductivity. Our study demonstrated that a unique optoelectronic property of organic crystals can be obtained by controlling the crystal’s morphology, which offers potential guidance for the future design and development of organic crystal optoelectronics.
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Arnott, H. J., M. A. Webb, and L. E. Lopez. "An SEM study of raphide crystal initials in the leaves of vitis (grape)." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 984–85. http://dx.doi.org/10.1017/s0424820100141299.
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Many papers have been published on the structure of calcium oxalate crystals in plants, however, few deal with the early development of crystals. Large numbers of idioblastic calcium oxalate crystal cells are found in the leaves of Vitis mustangensis, V. labrusca and V. vulpina. A crystal idioblast, or raphide cell, will produce 150-300 needle-like calcium oxalate crystals within a central vacuole. Each raphide crystal is autonomous, having been produced in a separate membrane-defined crystal chamber; the idioblast''s crystal complement is collectively embedded in a water soluble glycoprotein matrix which fills the vacuole. The crystals are twins, each having a pointed and a bidentate end (Fig 1); when mature they are about 0.5-1.2 μn in diameter and 30-70 μm in length. Crystal bundles, i.e., crystals and their matrix, can be isolated from leaves using 100% ETOH. If the bundles are treated with H2O the matrix surrounding the crystals rapidly disperses.
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Deng, Chun Lin, Ying Jun Wang, Yao Wu, Xin Long Wang, Xiao Feng Chen, Hua De Zheng, Ji Yong Chen, and Xing Dong Zhang. "Apatite Formation on Porous HA/TCP in Animals’ Serums In Vitro." Key Engineering Materials 330-332 (February 2007): 955–58. http://dx.doi.org/10.4028/www.scientific.net/kem.330-332.955.
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Porous HA/TCP bioceramics were immersed in pure dog serum to observe apatite formation. Deposited crystals were examined using SEM. Results showed that beamed sheet-like crystals formed on the surface of ceramics granules, and after postponement immersion time, crystals extended and became bigger. EDS and IR results suggested formed crystals were defect-calcium type carbonated hydroxyapatite. HRTEM photograph suggested formation process of new-formed crystals from non-crystal to crystal in serum. Directional organisms acted maybe as a template in process of crystals formation, so new crystals developed along certain direction.
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Wang, Haoyu, Jianhui Xiong, Man Li, Jufeng Geng, Shangke Pan, and Jianguo Pan. "Crystal Growth, Luminescence and Scintillation Characterizations of Cs2KLaCl6:Ce and Cs2KCeCl6." Crystals 11, no. 6 (June 8, 2021): 653. http://dx.doi.org/10.3390/cryst11060653.
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Elpasolite halides scintillation crystals have been proven to be very important materials for X-ray and γ-ray detector applications. The crystals of Cs2KLaCl6:4% Ce (CKLC) and Cs2KCeCl6 (CKCC) belong to novel scintillation of the Chloro-elpasolite crystal family. In this paper, the crystal growth of CKLC and CKCC crystals using the vertical Bridgman techniques were reported. The PXRD patterns showing both crystals have a cubic crystal structure. Both crystals have similar photoluminescence excitation and emission spectra, the fluorescence decay time of CKLC and CKCC crystals were about 49.7 and 33.8 ns. The energy resolution under the excitation of 662 keV γ-rays from a 137Cs source were found to be 6.6% and 5.2% (FWHM), respectively. The scintillation decay times of CKLC crystal were τ1 = 127 ns (33%) and τ2 = 1617 ns (67%), while that of CKCC crystal were τ1 = 2.86 ns (5%) and τ2 = 81 ns (95%).
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Yonenaga, Ichiro, Utako Onose, and Koji Sumino. "Mechanical properties of GaAs crystals." Journal of Materials Research 2, no. 2 (April 1987): 252–61. http://dx.doi.org/10.1557/jmr.1987.0252.
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Mechanical properties of GaAs crystals grown by the liquid encapsulated Czochralski technique and the boat technique are investigated by means of compression tests. Stressstrain characteristics of a GaAs crystal in the temperature range 400°–500°C are very similar to those of a Si crystal in the temperature range 800°–900°C. This seems to reflect the fact that the dislocation mobility in a GaAs crystal in the former temperature range is comparable to that in a Si crystal in the latter temperature range. Dislocations in GaAs crystals are found to be easily immobilized at an intermediate temperature due to gettering of impurities and/or impurity-point defect complexes. In comparison to a Si crystal, the surface of a GaAs crystal seems to involve irregularities that act easily as effective generation centers for dislocations. Thus the magnitude of the yield stress of an aged GaAs crystal is controlled by the surface condition and is not influenced by the density of dislocations involved in the crystal. The socalled steady state of deformation is realized in a GaAs crystal in the deformation stage after the lower yield point as in Si and Ge crystals. Dislocation distributions in a deformed GaAs crystal observed by transmission electron microscopy is very similar to those in deformed Si and Ge crystals.
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Tian, Ruifeng, Mingyan Pan, Lu Zhang, and Hongji Qi. "Crystal growth and spectral properties of (Yb0.15Lu0.85xY0.85-0.85x)3Al5O12 single crystals." Chinese Optics Letters 20, no. 12 (2022): 121601. http://dx.doi.org/10.3788/col202220.121601.
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Fisher, John G., Su-Hyeon Sim, Trung Thành Ðoàn, Eugenie Uwiragiye, Jungwi Mok, and Junseong Lee. "Comparison of (K0.5Na0.5)NbO3 Single Crystals Grown by Seed-Free and Seeded Solid-State Single Crystal Growth." Materials 16, no. 10 (May 10, 2023): 3638. http://dx.doi.org/10.3390/ma16103638.
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(K0.5Na0.5)NbO3-based piezoelectric ceramics are of interest as a lead-free replacement for Pb(Zr,Ti)O3. In recent years, single crystals of (K0.5Na0.5)NbO3 with improved properties have been grown by the seed-free solid-state crystal growth method, in which the base composition is doped with a specific amount of donor dopant, inducing a few grains to grow abnormally large and form single crystals. Our laboratory experienced difficulty obtaining repeatable single crystal growth using this method. To try and overcome this problem, single crystals of 0.985(K0.5Na0.5)NbO3-0.015Ba1.05Nb0.77O3 and 0.985(K0.5Na0.5)NbO3-0.015Ba(Cu0.13Nb0.66)O3 were grown both by seed-free solid-state crystal growth and by seeded solid-state crystal growth using [001] and [110]-oriented KTaO3 seed crystals. X-ray diffraction was carried out on the bulk samples to confirm that single-crystal growth had taken place. Scanning electron microscopy was used to study sample microstructure. Chemical analysis was carried out using electron-probe microanalysis. The single crystal growth behaviour is explained using the mixed control mechanism of grain growth. Single crystals of (K0.5Na0.5)NbO3 could be grown by both seed-free and seeded solid-state crystal growth. Use of Ba(Cu0.13Nb0.66)O3 allowed a significant reduction in porosity in the single crystals. For both compositions, single crystal growth on [001]-oriented KTaO3 seed crystals was more extensive than previously reported in the literature. Large (~8 mm) and relatively dense (<8% porosity) single crystals of 0.985(K0.5Na0.5)NbO3-0.015Ba(Cu0.13Nb0.66)O3 can be grown using a [001]-oriented KTaO3 seed crystal. However, the problem of repeatable single crystal growth remains.
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Bulutoglu, Pelin Su, Conor Parks, Nandkishor K. Nere, Shailendra Bordawekar, and Doraiswami Ramkrishna. "Exploring New Crystal Structures of Glycine via Electric Field-Induced Structural Transformations with Molecular Dynamics Simulations." Processes 7, no. 5 (May 8, 2019): 268. http://dx.doi.org/10.3390/pr7050268.
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Being able to control polymorphism of a crystal is of great importance to many industries, including the pharmaceutical industry, since the crystal’s structure determines significant physical properties of a material. While there are many conventional methods used to control the final crystal structure that comes out of a crystallization unit, these methods fail to go beyond a few known structures that are kinetically accessible. Recent studies have shown that externally applied fields have the potential to effectively control polymorphism and to extend the set of observable polymorphs that are not accessible through conventional methods. This computational study focuses on the application of high-intensity dc electric fields (e-fields) to induce solid-state transformation of glycine crystals to obtain new polymorphs that have not been observed via experiments. Through molecular dynamics simulations of solid-state α -, β -, and γ -glycine crystals, it has been shown that the new polymorphs sustain their structures within 125 ns after the electric field has been turned off. It was also demonstrated that strength and direction of the electric field and the initial structure of the crystal are parameters that affect the resulting polymorph. Our results showed that application of high-intensity dc electric fields on solid-state crystals can be an effective crystal structure control method for the exploration of new crystal structures of known materials and to extend the range of physical properties a material can have.
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Baba, Seiki, and Takashi Kumasaka. "A new protein crystal mounting method using humid air and glue coating." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1146. http://dx.doi.org/10.1107/s2053273314088536.
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Cryopreservation of protein crystals are a useful to reduce radiation damage for synchrotron experiments, the cryoloop mounting method using cryoprotectant agents is the widely used. However, Protein crystals are fragile, and they have often trouble to find a condition suitable for cryo-cooling. X-ray diffraction experiments at room temperature can evaluate the quality of the protein crystal and perform structural analysis without being affected shrink of the crystal by cryo-cooled and addition cryoprotectant agents. And, conventional humidity controlled method is possible to improve resolution of limited protein crystals [1]. However, protein crystals of these diffraction experiments cannot apply same mounting method. We developed a new crystal mounting method, the humid air and glue-coating (HAG) mounting method, which involves a combination of controlled adjustable humid air and water-soluble polymer glue for crystal coating [2]. By coating with the water-soluble polymer glue, most crystals exposed to the controlled humid air were stable at room temperature and could be cryocooled under optimized humidity without additional cryoprotectant agents. For example, the crystals of the bacterial hydrolase RsbQ was mechanically very fragile and sensitive to environmental changes. Thus, RsbQ crystal cannot apply cryoloop mount with cryoprotectant agents. By using the HAG method, we were able to obtain 1.4 Å data and solve its structure. For another example, membrane protein crystal was improved resolution to optimize humidity. The crystals by using HAG method reproducibly showed crystal lattice transformation in response to a change in humidity, thus using this method a series of isomorphic crystals can be prepared. We introduce HAG method, and demonstrate its success with various protein crystals.
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Furukawa, Yoshinori. "Ice Crystals." Crystals 9, no. 10 (October 19, 2019): 540. http://dx.doi.org/10.3390/cryst9100540.
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The special issue on “Ice Crystals” includes seven contributed papers, which give the wide varieties of topics related to ice crystals. They focus on the interface structure of ice, the physical properties of hydrate crystals and the freezing properties of water controlled by antifreeze proteins. The present issue can be considered as a status report reviewing the research that has been made recently on ice crystals. These papers provide research information about the recent development of ice crystal research to readers.
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Yu, Youjia, Qiaoyan Jiang, Hua Wan, Rong Li, Yang Sun, Zhiwei Zhang, Zhengsheng Mao, Yue Cao, and Feng Chen. "In Situ Identification of Unknown Crystals in Acute Kidney Injury Using Raman Spectroscopy." Nanomaterials 12, no. 14 (July 13, 2022): 2395. http://dx.doi.org/10.3390/nano12142395.
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Raman spectroscopy is a well-established and powerful tool for in situ biomolecular evaluation. Type 2 crystal nephropathies are characterized by the deposition of crystalline materials in the tubular lumen, resulting in rapid onset of acute kidney injury without specific symptoms. Timely crystal identification is essential for its diagnosis, mechanism exploration and therapy, but remains challenging. This study aims to develop a Raman spectroscopy-based method to assist pathological diagnosis of type 2 crystal nephropathies. Unknown crystals in renal tissue slides from a victim suffered extensive burn injury were detected by Raman spectroscopy, and the inclusion of crystals was determined by comparing Raman data with established database. Multiple crystals were scanned to verify the reproducibility of crystal in situ. Raman data of 20 random crystals were obtained, and the distribution and uniformity of substances in crystals were investigated by Raman imaging. A mouse model was established to mimic the crystal nephropathy to verify the availability of Raman spectroscopy in frozen biopsy. All crystals on the human slides were identified to be calcium oxalate dihydrate, and the distribution and content of calcium oxalate dihydrate on a single crystal were uneven. Raman spectroscopy was further validated to be available in identification of calcium oxalate dihydrate crystals in the biopsy specimens. Here, a Raman spectroscopy-based method for in situ identification of unknown crystals in both paraffin-embedded tissues and biopsy specimens was established, providing an effective and promising method to analyze unknown crystals in tissues and assist the precise pathological diagnosis in both clinical and forensic medicine.
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Cuttitta, Christina M., Daniel L. Ericson, Alexander Scalia, Christian G. Roessler, Ella Teplitsky, Karan Joshi, Olven Campos, et al. "Acoustic transfer of protein crystals from agarose pedestals to micromeshes for high-throughput screening." Acta Crystallographica Section D Biological Crystallography 71, no. 1 (January 1, 2015): 94–103. http://dx.doi.org/10.1107/s1399004714013728.
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Acoustic droplet ejection (ADE) is an emerging technology with broad applications in serial crystallography such as growing, improving and manipulating protein crystals. One application of this technology is to gently transfer crystals onto MiTeGen micromeshes with minimal solvent. Once mounted on a micromesh, each crystal can be combined with different chemicals such as crystal-improving additives or a fragment library. Acoustic crystal mounting is fast (2.33 transfers s−1) and all transfers occur in a sealed environment that is in vapor equilibrium with the mother liquor. Here, a system is presented to retain crystals near the ejection point and away from the inaccessible dead volume at the bottom of the well by placing the crystals on a concave agarose pedestal (CAP) with the same chemical composition as the crystal mother liquor. The bowl-shaped CAP is impenetrable to crystals. Consequently, gravity will gently move the crystals into the optimal location for acoustic ejection. It is demonstrated that an agarose pedestal of this type is compatible with most commercially available crystallization conditions and that protein crystals are readily transferred from the agarose pedestal onto micromeshes with no loss in diffraction quality. It is also shown that crystals can be grown directly on CAPs, which avoids the need to transfer the crystals from the hanging drop to a CAP. This technology has been used to combine thermolysin and lysozyme crystals with an assortment of anomalously scattering heavy atoms. The results point towards a fast nanolitre method for crystal mounting and high-throughput screening.
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Vaidya, Rajiv, Mehul Dave, and Kaushik R. Patel. "Electrical Properties of WSe2-X Single Crystals Grown By Direct Vapour Transport Technique." YMER Digital 21, no. 02 (February 17, 2022): 440–47. http://dx.doi.org/10.37896/ymer21.02/44.
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The single crystals of WSe2-x were grown by direct vapour transport technique. The grown crystals possess hexagonal crystal structure. The resistivities of the as grown crystals were measured using van der Pauw method. The Hall parameters of the grown crystals were determined at room temperature from Hall effect measurements. Electrical resistivity measurements were performed on this crystal in the temperature range 303–423 K. The crystals werefound to exhibit semiconducting nature in this range. The activation energy and anisotropy measurements were carried out for this crystal. The value of resistivity is increases with increasing selenium content. The results obtained are discussed in detail.
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Knepp, T. N., T. L. Renkens, and P. B. Shepson. "Measurement of acidic ions and their qualitative effects on snow crystal morphology and the quasi-liquid layer." Atmospheric Chemistry and Physics Discussions 9, no. 1 (January 9, 2009): 735–66. http://dx.doi.org/10.5194/acpd-9-735-2009.
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Abstract. A chamber was constructed within which snow crystals were grown on a string at various temperatures, relative humidities, and acetic acid gas phase mole fraction. The temperature, relative humidity, and acid mole fraction were measured for the first time at the point of crystal growth. Snow crystal morphological transition temperature shifts were recorded as a function of acid mole fraction, and interpreted according to the calculated acid concentration in the crystal's quasi-liquid layer, which increased in thickness as a function of acid mole fraction, thereby affecting the crystal's morphology according to the hypothesis of Kuroda and Lacmann. Deficiencies in the understanding of the quasi-liquid layer and its role in determining snow crystal morphology are briefly discussed.
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Alemu, Dessale, Idris Shafi, and Tizazu Abza. "Synthesis, growth and characterization of magnesium chloride doped L-alanine cadmium chloride single crystal: For nonlinear optical application." East African Journal of Biophysical and Computational Sciences 3, no. 2 (October 24, 2022): 61–67. http://dx.doi.org/10.4314/eajbcs.v3i2.6s.
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The aim of this research was to synthesize and characterize pure and magnesium chloride (MgCl2) doped L–alanine cadmium chloride (LACC) single crystals. Pure and MgCl2 doped LACC single crystals were synthesized by solution method with slow evaporation solution growth technique at room temperature. The single crystal X-ray diffraction studies of pure, 1 and 2 mol% MgCl2 doped LACC single crystals revealed monoclinic crystal structure with C2 space group. The optical properties of pure and MgCl2 doped LACC single crystals investigated by UV–VIS/NIR spectrometer confirmed that the crystals were transparent in the wavelength range of 230-1100 nm. The optical band gap energy of pure and doped LACC single crystals were found to have the same value of 5.4 eV. The energy-dispersive X-ray analysis indicated the incorporation of magnesium and chlorine atoms in LACC single crystal. The second harmonic generation efficiency of 1 and 2 mol% MgCl2 doped LACC crystals were analyzed by Kurtz-Perry powder technique and found to be 1.75 and 2 times greater than that of the standard potassium dihydrogen phosphate crystal, respectively.
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Wang, Xu Ping, Ji Yang Wang, and Bing Liu. "Growth and Properties of Cubic Potassium Tantalate Niobate Crystals." Advanced Materials Research 306-307 (August 2011): 352–57. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.352.
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Cubic KTa1-xNbxO3single crystals with difference compositions have been grown by Czochralski technique in KTaO3- KNbO3solid solution system. Growth habit, morphological feature, and other properties of two different composition KTN crystals, KTa0.65Nb0.35O3, and KTa0.63Nb0.37O3are investigated in this work. The X-ray diffraction (XRD) experimental results show that all crystals belong to cubic phase at room temperature, lattice parameterais 3.993 and 3.994Å corresponded to the composition of x (Nb) =0.35, 0.37, respectively. HXRD and AFM measurement results show all KTN crystals are in high integrity and good quality. The transmittance spectra of KTN crystals show that the cut off wavelength of KTN crystals decreased with the Nb increasing in the crystal. The dielectric-temperature measurement results shows KTN crystal have optimal performance on Kerr effect at the Currie temperature of the crystal. All the results show that the KTN crystals we grown are in good quality and have a broad application prospects
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Yeo, Im Gyu, Tae Woo Lee, Jong Hwi Park, Woo Sung Yang, Heui Bum Ryu, Mi Seon Park, Il Soo Kim, et al. "Effect of the Seed Polarity for High Quality 4H-SiC Crystal Grown on 6H-SiC Seed by PVT Method." Materials Science Forum 679-680 (March 2011): 44–47. http://dx.doi.org/10.4028/www.scientific.net/msf.679-680.44.
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The single crystal ingots by using a sublimation technique were grown on 6H-SiC dual-seed crystals with opposite face polarities and then SiC crystal wafers sliced from the SiC ingot were systematically investigated to find out the polarity dependence of the crystal quality. The growth rate of the SiC crystal grown in this study was about 0.2mm/hr. N-type 2’’ SiC crystals exhibiting the 4H- and 6H-SiC polytype were successfully fabricated on C-face and Si-face, respectively. The incorporation of nitrogen donors in the SiC crystals grown on the C-face seed crystal was exhibited to be higher than in SiC crystals grown on a Si-face crystal. When the SiC crystal ingot proceeded to grow, the SiC crystal region grown on the C-face seed crystal was enlarged compared to the SiC crystal region on the Si-face seed crystal.
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Mahendra, K., and N. K. Udayashankar. "A study on structural, optical, thermal and electrical properties of the amaranth dye-doped KHOOD single crystal." International Journal of Modern Physics B 34, no. 04 (December 30, 2019): 2050002. http://dx.doi.org/10.1142/s0217979220500022.
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Influence of amaranth dye on the potassium hydrogen oxalate oxalic acid dihydrate (KHOOD) single crystal is investigated. The structural studies were carried out to understand the crystal behavior after dye incorporation. Optical studies were performed to investigate the photon absorption of the crystal with or without the presence of dye molecule. The absorption of pure crystals were also compared with that of amaranth dye-doped crystals and the bandgap was estimated. The surface morphology and the presence of dye molecules are investigated using scanning electron microscope (SEM) and EDX analysis. The elemental mapping was carried out to understand the distribution of elements in the crystal surface. The thermal behavior of the crystal was studied and compared with that of KHOOD and dye-doped KHOOD crystals in detail. The emission properties of the crystals were studied and compared crystal. Field-dependent [Formula: see text]–[Formula: see text] studies were performed to study the conductivity of the crystals and results were discussed in detail.
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Shinners, Tracy C., and Jalpa P. Tewari. "Diversity in crystal production by some bird's nest fungi (Nidulariaceae) in culture." Canadian Journal of Chemistry 75, no. 6 (June 1, 1997): 850–56. http://dx.doi.org/10.1139/v97-103.
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Hyphae of many species of bird's nest fungi (Nidulariaceae) were examined for the presence of crystals. Scanning electron microscopy revealed crystals typical of calcium oxalate associated with hyphae. Crystal depositions included complete hyphal encrustation, organized druses, randomly arranged groups, single crystals, and relatively "clean" hyphae. The majority of crystals could be morphologically classified as styloid, raphide, or bipyramidal type. Energy-dispersive X-ray microanalyses confirmed that all crystal types were rich in calcium, and X-ray diffraction identified both the dihydrate (weddellite) and monohydrate (whewellite) forms of calcium oxalate. Morphological variation of crystals was species and medium specific, with generally more crystals being produced on relatively calcium-rich V8 juice agar than on PDA. No association was found between crystal types and geographic and habitat distribution of species. Keywords: wood rotting fungus, decomposition, calcium oxalate.
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Uwiragiye, Eugenie, Thuy Linh Pham, Jong-Sook Lee, Byoung-Wan Lee, Jae-Hyeon Ko, and John G. Fisher. "0.98(K0.5Na0.5)NbO3–0.02(Bi0.5Na0.5)(Zr0.85Sn0.15)O3 Single Crystals Grown by the Seed-Free Solid-State Crystal Growth Method and Their Characterization." Ceramics 7, no. 3 (June 21, 2024): 840–57. http://dx.doi.org/10.3390/ceramics7030055.
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(K0.5Na0.5)NbO3-based single crystals are of interest as high-performance lead-free piezoelectric materials, but conventional crystal growth methods have some disadvantages such as the requirement for expensive Pt crucibles and difficulty in controlling the composition of the crystals. Recently, (K0.5Na0.5)NbO3-based single crystals have been grown by the seed-free solid-state crystal growth method, which can avoid these problems. In the present work, 0.98(K0.5Na0.5)NbO3–0.02(Bi0.5Na0.5)(Zr0.85Sn0.15)O3 single crystals were grown by the seed-free solid-state crystal growth method. Sintering aids of 0.15 mol% Li2CO3 and 0.15 mol% Bi2O3 were added to promote single crystal growth. Pellets were sintered at 1150 °C for 15–50 h. Single crystals started to appear from 20 h. The single crystals grown for 50 h were studied in detail. Single crystal microstructure was studied by scanning electron microscopy of the as-grown surface and cross-section of the sample and revealed porosity in the crystals. Electron probe microanalysis indicated a slight reduction in K and Na content of a single crystal as compared to the nominal composition. X-ray diffraction shows that the single crystals contain mixed orthorhombic and tetragonal phases at room temperature. Raman scattering and impedance spectroscopy at different temperatures observed rhombohedral–orthorhombic, orthorhombic–tetragonal and tetragonal–cubic phase transitions. Polarization–electric field (P–E) hysteresis loops show that the single crystal is a normal ferroelectric material with a remanent polarization (Pr) of 18.5 μC/cm2 and a coercive electrical field (Ec) of 10.7 kV/cm. A single crystal presents d33 = 362 pC/N as measured by a d33 meter. Such a single crystal with a large d33 and high Curie temperature (~370 °C) can be a promising candidate for piezoelectric devices.
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Tsuge, Hiroshi, Shinya Sato, Masakazu Katsuno, Tatsuo Fujimoto, and Wataru Ohashi. "Growth of High Quality 4H-SiC Crystals in Controlled Temperature Distributions of Seed Crystals." Materials Science Forum 717-720 (May 2012): 13–16. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.13.
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Large diameter 4H-SiC single crystal wafers with higher quality are required to improve the yields of devices fabricated onto the SiC wafers. For crystal growths with higher quality, it is important to prepare seed crystals with lower defect densities. In particular, the edge part of the seed has to be prepared with considerable care because the crystallinity of the enlarged part of grown crystals depends much upon the surface condition of the seed crystal during radial expansion growth. We found that growth with fewer defect and micropipe densities, specifically at the periphery of the crystal, is possible by utilizing in-situ etching process for the seed crystal surface. We have also performed intense numerical calculations of the temperature distribution around the seed surface, and discussed growth conditions which cause the in-situ etching effective to improvement of the crystallinity in enlarged crystals.
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Tang, Min, and Yi-Liang Li. "A Complex Assemblage of Crystal Habits of Pyrite in the Volcanic Hot Springs from Kamchatka, Russia: Implications for the Mineral Signature of Life on Mars." Crystals 10, no. 6 (June 23, 2020): 535. http://dx.doi.org/10.3390/cryst10060535.
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In this study, the crystal habits of pyrite in the volcanic hot springs from Kamchatka, Russia were surveyed using scanning electron microscopy. Pyrite crystals occur either as single euhedral crystals or aggregates with a wide range of crystal sizes and morphological features. Single euhedral crystals, with their sizes ranging from ~200 nm to ~40 µm, exhibit combinations of cubic {100}, octahedral {111}, and pyritohedral {210} and {310} forms. Heterogeneous geochemical microenvironments and the bacterial activities in the long-lived hot springs have mediated the development and good preservation of the complex pyrite crystal habits: irregular, spherulitic, cubic, or octahedral crystals congregating with clay minerals, and nanocrystals attaching to the surface of larger pyrite crystals and other minerals. Spherulitic pyrite crystals are commonly covered by organic matter-rich thin films. The coexistence of various sizes and morphological features of those pyrite crystals indicates the results of secular interactions between the continuous supply of energy and nutritional elements by the hot springs and the microbial communities. We suggest that, instead of a single mineral with unique crystal habits, the continuous deposition of the same mineral with a complex set of crystal habits results from the ever-changing physicochemical conditions with contributions from microbial mediation.
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Mandel, N. "Crystal-membrane interaction in kidney stone disease." Journal of the American Society of Nephrology 5, no. 5 (November 1994): S37. http://dx.doi.org/10.1681/asn.v55s37.
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Urolithiasis is a multifaceted process that initiates with the formation of microcrystals in the urine and terminates with the formation of mature renal calculi. The attachment of crystals by the urothelium is a major event in the successful formation of the mature stone. The papillary tip is the primary site for crystal attachment and stone maturation, and the attachment process appears to be mediated by specific molecular interactions between molecular structures on the surfaces of stone crystals and molecular arrays on the surfaces of cell membranes. Animal models have demonstrated the interaction between cells and crystals, and they have suggested a correlation between cellular damage and crystal interaction, especially when crystals bind to and then break free from the tubular epithelium. Cell culture studies on inner medullary late collecting duct (IMCD) cells have demonstrated that calcium oxalate monohydrate, hydroxyapatite, and uric acid crystals bind to IMCD cells in primary culture. The attachment of these crystals to IMCD cells was crystal structure dependent, saturable, and competitively inhibitable if more than one crystal type was present at the same time. The crystals preferentially attach to cells that have lost partial or complete intercellular junctional integrity. These crystal-attaching cells appear to have altered membrane composition and/or structure. Recent studies on red blood cells and IMCD cells that have been enriched with cholesterol and selected phospholipids suggest that crystal-membrane phospholipid interactions play a major role in crystal attachment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Lieske, J. C., R. Leonard, and F. G. Toback. "Adhesion of calcium oxalate monohydrate crystals to renal epithelial cells is inhibited by specific anions." American Journal of Physiology-Renal Physiology 268, no. 4 (April 1, 1995): F604—F612. http://dx.doi.org/10.1152/ajprenal.1995.268.4.f604.
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Adhesion of urinary crystals to the apical surface of renal tubular cells could be a critical step in the formation of kidney stones. The interaction between renal epithelial cells (BSC-1 line) and the most common crystal in kidney stones, calcium oxalate monohydrate (COM), was studied in a tissue culture model system. COM crystals bound to the cell surface within seconds in a concentration-dependent manner to a far greater extent than did brushite, another calcium-containing crystal found in urine. Adhesion of COM crystals to cells was blocked by the polyanion, heparin. Other glycosaminoglycans including chondroitin sulfate A or B, heparan sulfate, and hyaluronic acid, but not chondroitin sulfate C, prevented binding of COM crystals. Two nonsulfated polyanions, polyglutamic acid and polyaspartic acid, also blocked adherence of COM crystals. Three molecules found in urine, nephrocalcin, uropontin, and citrate, each inhibited binding of COM crystals, whereas Tamm-Horsfall glycoprotein (THP) did not. Prior exposure of crystals but not cells to inhibitory molecules blocked adhesion, suggesting that these agents exert their effect at the crystal surface. Inhibition of crystal binding followed a linear Langmuir adsorption isotherm for each inhibitor identified, suggesting that these molecules bind to a single class of sites on the crystal that are important for adhesion to the cell surface. Inhibition of crystal adhesion by heparin was rapidly overcome by the polycation protamine, suggesting that the glycosaminoglycan regulates cell-crystal interactions in a potentially reversible manner.(ABSTRACT TRUNCATED AT 250 WORDS)
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Adnan, Siti Zubaidah, and Noor Asma Fazli Abdul Samad. "Effects of Nucleation and Crystal Growth Rates on Crystal Size Distribution for Seeded Batch Potash Alum Crystallization Process." ASEAN Journal of Chemical Engineering 22, no. 2 (December 29, 2022): 258. http://dx.doi.org/10.22146/ajche.74121.
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The driving force of the cooling crystallization process is supersaturation, where the supersaturation level during the crystallization process is crucial to grow the crystal sufficiently. Nucleation and crystal growth rates are two concurrent phenomena occurring during crystallization. Both are supersaturation functions that determine the growth of seed crystals and the formation of fine crystals. Trade-offs between nucleation and crystal growth are essential for achieving the large size of seed crystals with the minimum number of fine crystals. Thus, the objective of this study is to analyze the effects of nucleation and crystal growth rates on final product quality, which is crystal size distribution (CSD). Modeling of the crystallization process using a potash alum case study is highlighted and simulated using Matlab software. Then, the effects of nucleation rate, crystal growth rate, and both nucleation and crystal growth rates on CSD are evaluated using local sensitivity analysis based on the one-factor-at-a-time (OFAT) method. Based on simulation results for all strategies, a low combined rate delivers the best performance of the final CSD compared to others. Its primary peak has a mean crystal size of 455 µm with 0.0078 m3/m volume distribution. This means that the grown seed crystals are large with high volume distribution compared to the nominal strategy, which is at the mean crystal size of 415 µm and 0.00434 m3/m. Meanwhile, the secondary peak has the mean crystal size of 65 µm, 0.00028 m3/m in volume distribution. This corroborates the least number of fine crystals at the considerably small size compared to nominal’s (0.00151 m3/m, 35 µm). Overall, the low nucleation and crystal growth rates strategy provides useful insights into designing temperature profiles during the linear cooling crystallization process, whereby achievable supersaturation levels in obtaining large crystals with fewer crystal fines are provided via simulation.
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Cao, Hui-Ling, Li-Hua Sun, Jian Li, Lin Tang, Hui-Meng Lu, Yun-Zhu Guo, Jin He, et al. "A quality comparison of protein crystals grown under containerless conditions generated by diamagnetic levitation, silicone oil and agarose gel." Acta Crystallographica Section D Biological Crystallography 69, no. 10 (September 20, 2013): 1901–10. http://dx.doi.org/10.1107/s0907444913016296.
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High-quality crystals are key to obtaining accurate three-dimensional structures of proteins using X-ray diffraction techniques. However, obtaining such protein crystals is often a challenge. Several containerless crystallization techniques have been reported to have the ability to improve crystal quality, but it is unknown which is the most favourable way to grow high-quality protein crystals. In this paper, a quality comparison of protein crystals which were grown under three containerless conditions provided by diamagnetic levitation, silicone oil and agarose gel was conducted. A control experiment on a vessel wall was also simultaneously carried out. Seven different proteins were crystallized under the four conditions, and the crystal quality was assessed in terms of the resolution limit, the mosaicity and theRmerge. It was found that the crystals grown under the three containerless conditions demonstrated better morphology than those of the control. X-ray diffraction data indicated that the quality of the crystals grown under the three containerless conditions was better than that of the control. Of the three containerless crystallization techniques, the diamagnetic levitation technique exhibited the best performance in enhancing crystal quality. This paper is to our knowledge the first report of improvement of crystal quality using a diamagnetic levitation technique. Crystals obtained from agarose gel demonstrated the second best improvement in crystal quality. The study indicated that the diamagnetic levitation technique is indeed a favourable method for growing high-quality protein crystals, and its utilization is thus potentially useful in practical efforts to obtain well diffracting protein crystals.
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Miura, Hiromi, Taku Sakai, H. Nogawa, Xu Yue Yang, Yoshimi Watanabe, and Seiji Miura. "Orientation Dependence of Ductility of Mg Single Crystals at Elevated Temperature." Materials Science Forum 488-489 (July 2005): 193–96. http://dx.doi.org/10.4028/www.scientific.net/msf.488-489.193.
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Orientation-controlled Mg single crystals were tensile tested at temperatures between 473 K and 673 K at a strain rate of 4.2 x 10-4 s-1 in vacuum. Though all the single crystals showed high ductility compared with that of polycrystals, the ductility of the single crystals strongly depended on the crystal orientation. The [27 -1 -26 1] single crystal showed 0.57 fracture strain, while the [3 8 -11 -1] single crystal showed superplastic behavior of ductility over 1.8 strain. The observed strong orientation dependence of ductility seemed to be caused by orientation dependence of ease occurrence of dynamic recrystallization (DRX) in the single crystals during high-temperature deformation. The orientation dependence of ductility of Mg single crystals will be discussed in detail concerning crystallographical orientations of the single crystals, occurrence of DRX and fracture.
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Yin, Libin, Sheng Wang, Kainan Xiong, Xiaoniu Tu, Jiayue Xu, Yanqing Zheng, and Erwei Shi. "Bridgman Growth of New Nonlinear Optical Crystal (La1 − xSmx)3Ga5.5Nb0.5O14 for Quasi-Parametric Chirped Pulse Amplification." Crystals 9, no. 11 (November 9, 2019): 587. http://dx.doi.org/10.3390/cryst9110587.
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Samarium-doped La3Nb0.5Ga5.5O14 (Sm:LGN) crystals were grown along a (100)-orientation by the Bridgman method for quasi-parametric chirped pulse amplification (QPCPA) applications. The structure of La1-xSxmGN (x = 0.1, 0.2) crystals was the same as that of La3Nb0.5Ga5.5O14 (LGN) crystals. The effective segregation coefficient of Sm3+ in the La0.9Sm0.1GN crystal was 0.140. The full width at half maximum (FWHM) of La1-xSxmGN (x = 0.1,0.2) crystals was lower than 50″, which indicated the high quality of the crystals. The density of the La0.9Sm0.1GN crystal was 5.968 g/cm3 and that of the La0.8Sm0.2GNcrystal was 5.988 g/cm3. The transmittance of the crystals at 532nm and 800nm was all above 73%. The absorption spectra indicated that the crystals had strong absorption peaks at wavelengths of 1544 and 1595 nm. The thermal properties of La1-xSxmGN (x = 0.1, 0.2) crystals were similar to those of the LGN crystals. The laser damage thresholds of La0.9Sm0.1GN and La0.8Sm0.2GN crystals were, respectively, 188.30 and 54.84 TW/cm2 (@800 nm,35 fs).
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Guidi, Vincenzo, Valerio Bellucci, Riccardo Camattari, and Ilaria Neri. "Proposal for a Laue lens with quasi-mosaic crystalline tiles." Journal of Applied Crystallography 44, no. 6 (October 4, 2011): 1255–58. http://dx.doi.org/10.1107/s0021889811035709.
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Quasi-mosaicity is an effect of secondary bending within a crystal driven by crystalline anisotropy. This effect can be used to fabricate a series of curved crystals for the realization of a Laue lens. It is highlighted that crystals bent by the quasi-mosaic effect allow very high resolution focusing with respect to mosaic crystals. Under the same conditions for energy passband, crystal size and flux of incident photons, a Laue lens based on quasi-mosaic crystals would increase the signal-to-noise ratio by about an order of magnitude compared to the same lens with mosaic crystals. Moreover, no mosaic defocusing occurs for quasi-mosaic crystals.
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Sun, Zhenjie. "Application of third-order nonlinear optical materials in complex crystalline chemical reactions of borates." Nonlinear Engineering 11, no. 1 (January 1, 2022): 609–14. http://dx.doi.org/10.1515/nleng-2022-0234.
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Abstract In order to explore the application of third-order nonlinear optical (NLO) materials in complex borate crystalline chemical reactions, the laser light source with limited wavelength range can be extended to ultraviolet (UV) and deep UV region by using NLO crystal materials and frequency conversion technology, which has become a hot research direction of deep UV light source. The experimental results show that the UV cutoff edge of the grown KLi(HC3N3O3)·2H2O crystal is 237 nm. The refractive index of the crystal was measured by prism coupling technique, and the Sellmeier equation of the refractive index of the crystal was fitted. The chemical bond of the crystal is a fundamental means to understand the relationship between structure and properties. With the emergence of a large number of hybrid functional crystals, the composition and structure of crystals become more complex, and the chemical bond theory has also been greatly developed, and then the chemical bond theory of meta crystals or complex crystals has emerged. Once proposed, the theory has been widely used, such as analyzing the eligibility of luminescent crystals, NLO crystals and high-temperature superconductor crystals. NLO materials are the dominant field of China in the world. Crystals with good nonlinear behavior have more complex crystal structures, due to the theory of amorphous structure, the exploration of this aspect is particularly difficult. For the first time, the influence of the composition of rare earth-doped bismuth borate glass on the crystal precipitation and glass microstructure of NLO materials was systematically studied, which laid a theoretical foundation for further development and understanding of new bismuth borate optical systems.
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Wang, Xu, and Yongmin Zhou. "Research on Single Crystal Preparation via Dynamic Liquid Phase Method." Crystals 13, no. 7 (July 24, 2023): 1150. http://dx.doi.org/10.3390/cryst13071150.
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Traditional liquid phase methods for growing single crystals are static growth methods, which include seed crystal sedimentation growth and seed crystal clamping growth using seed crystal holders. Single crystals grown via seed crystal sedimentation often have a flat and elongated shape, and the region in contact with the bottom of the container is restricted during growth, resulting in significant defects. Similarly, the seed crystal clamping growth method cannot avoid contact with external objects, leading to abnormal growth at the contact points and along the direction of the seed crystal holder, also resulting in certain defects. Both of these growth methods require processes, such as cutting and grinding, to remove defects, resulting in resource waste. To address the shortcomings of the static liquid phase single-crystal preparation mentioned above, this study successfully designed a dynamic liquid phase method for single crystal growth, which achieved the successful suspension of seed crystals in the mother solution and the growth of high-quality, large-sized single crystals, avoiding contact with the walls and the bottom of the container during the crystal growth process. Based on the dynamic liquid phase single crystal growth apparatus mentioned above, stable and dynamic liquid phase preparation was successfully achieved, ranging from seed crystals with a diameter of approximately 5 mm to single crystals with a diameter of approximately 20 mm, by controlling the cooling rate and adjusting the solution flow rate.
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Teidearu, Tenno. "Crystal Shops and Shopping for Crystals in Estonia: Materiality and Experience as Sources of Value." Numen 70, no. 5-6 (September 4, 2023): 514–41. http://dx.doi.org/10.1163/15685276-20231704.
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Abstract This article concentrates on crystal shops and shopping for crystals in Estonia. Consumption and commerce are inherent parts of New Spirituality. Crystals became the most salient commodities in esoteric shops during the 2010s, most of the shops having become “crystal shops” in Estonia. The aim of this article is to analyze the meaning-making potential of the materiality of crystals in shopping, and the material and sensuous aspects of crystal shops. From the perspective of material culture and consumption studies, this case study proposes that crystals are valuable in shopping primarily because of their materiality as a source of meaning and experience. In choosing crystals, people follow their material form and material qualities instead of a textual description of their supportive effects. Crystal shops are generally described as therapeutic places, however as an “experiencescape” they are strictly sensuous and material places.
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Masařík, Vladimír, Pavel Novák, Arlette Zikánová, Jan Kornatowski, Jaroslav Maixner, and Milan Kočiřík. "Sorption and Transport of Species in Silicalite Study of Binary Systems Containing Iodine." Collection of Czechoslovak Chemical Communications 63, no. 3 (1998): 321–37. http://dx.doi.org/10.1135/cccc19980321.
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Sorption of iodine from both the vapour phase and iodine solutions in organic solvents on large Silicalite-1 crystals was investigated. The single component sorption of iodine and sorption from binary mixtures under co-diffusion conditions led to a uniform colouring of the crystals. Under counter-diffusion conditions with crystals saturated initially with vapour of a selected solvent, the sorption kinetics of iodine was 2 or 3 orders of magnitude slower as compared with the corresponding co-diffusion experiment. Colouring of crystals was always, at least in its initial stage, non-uniform with visualized pyramids at crystal basal planes. This finding together with the nature of outer and inner crystal morphology suggests that our Silicalite-1 crystals are 90°-intergrowths which have only pore mouth openings of sinusoidal channels in the crystal surface. The process of crystal colouring under counter-diffusion conditions seems to proceed via diffusion along the boundaries of crystal sections.
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Munuswamy, E., V. Krishnan, and S. Amerjothy. "Occurrence, type and location of calcium oxalate crystals in selected medicinal plants." Journal of Applied and Advanced Research 1, no. 4 (January 23, 2017): 21. http://dx.doi.org/10.21839/jaar.2016.v1i4.44.
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Crystals in selected medical plants growing naturally in Place palayam reserve forest, Thiruvallur District were studied with Polarised light microscope. Four types of crystals were observed: druses, prismatics, raphide and rosettes crystal. Druses more in cortical parenchyma and ground parenchyma cells in the stem & petiole region. In contrast prismatic, raphide and rosettes present in cortical, ground, axial and phloem parenchyma in the roots and stems. The Preliminary results show the presence of four types of calcium oxalate crystals in the stems, Petiole & roots of 10 Species: Achyranthes aspera, Aerva lanata, Atalantia monophylla, Bridelia Crenulata presence of Druses crystal, Plumeria rubra, Adhatoda zeylanica presence of prismatic crystal, Asparagus racemosus, Monochoria vaginalis presence of raphide crystal and Carica papaya and Carissa spinarum presence of rosette type of crystal. These observations indicate that there is relationship between the distribution of calcium oxalate crystals and the medicinal parts of the plant and supports the view that the presence of calcium oxalate crystals may relate to the adulterants.
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Kannan, Rajesh, G. Narayanasamy, S. Subramanian, and P. Selvarajan. "Spectroscopic, thermal, second order and third order NLO studies of N, N’ -dimethyl urea crystal." Journal of Applied and Advanced Research 1, no. 1 (January 23, 2018): 1. http://dx.doi.org/10.21839/jaar.2018.v1i1.124.
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Nonlinear optical (NLO) crystals are classified into organic, inorganic and semi organic crystals and these crystals are used in the fields of optical communication, optical computing, frequency doubling, optical data processing and opto electronics. In this work an organic NLO crystal namely DMU crystal was prepared. Slow evaporation technique was adopted to grow the single crystals of DMU after the growth period of 35 days. The harvested crystals have been subjected to various characterization techniques like XRD, FTIR, FT-Raman, TG/DTA, SHG, EDAX, impedance, optical and Z-scan studies. From the studies, is observed that DMU crystal has orthorhombic structure and it has the melting point at 105 oC and has the decomposition point at 275 oC. The relative SHG efficiency of DMU crystal was found to be more than one and third order NLO parameters were evaluated. The optical band gap of DMU crystal was found to be 5.008 eV.The results from various studies were analyzed.
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Kannan, Rajesh, G. Narayanasamy, S. Subramanian, and P. Selvarajan. "Spectroscopic, thermal, second order and third order NLO studies of N, N’ -dimethyl urea crystal." Journal of Applied and Advanced Research 3, no. 1 (January 23, 2018): 1. http://dx.doi.org/10.21839/jaar.2018.v3i1.124.
Full textAbstract:
Nonlinear optical (NLO) crystals are classified into organic, inorganic and semi organic crystals and these crystals are used in the fields of optical communication, optical computing, frequency doubling, optical data processing and opto electronics. In this work an organic NLO crystal namely DMU crystal was prepared. Slow evaporation technique was adopted to grow the single crystals of DMU after the growth period of 35 days. The harvested crystals have been subjected to various characterization techniques like XRD, FTIR, FT-Raman, TG/DTA, SHG, EDAX, impedance, optical and Z-scan studies. From the studies, is observed that DMU crystal has orthorhombic structure and it has the melting point at 105 oC and has the decomposition point at 275 oC. The relative SHG efficiency of DMU crystal was found to be more than one and third order NLO parameters were evaluated. The optical band gap of DMU crystal was found to be 5.008 eV.The results from various studies were analyzed.
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Li, Yang, Zhenshi Li, Baoan Liu, Xun Sun, Mingxia Xu, Lisong Zhang, Xian Zhao, and Guodong Lei. "Hybrid Density Functional Theory Calculations for the Crystal Structure and Electronic Properties of Al3+ Doped KDP Crystals." Crystals 14, no. 5 (April 27, 2024): 410. http://dx.doi.org/10.3390/cryst14050410.
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Intentionally adding select ions such as Al3+ could be helpful in controlling the crystal habit of KDP crystal for high yield of optics. The study of how Al3+ ions affect crystal quality can provide a basis for selecting an appropriate doping level without negatively affecting the optical properties of crystals. Here, the influence of Al3+ ions on the crystal structure and properties of KDP crystals have been investigated by using first-principles calculations. Theoretical calculations show that Al3+ ions mainly replace K sites in KDP crystals and could complex with intrinsic VH− point defects to form AlK2+ + 2VH− cluster defects. The linear absorption spectra indicate that the presence of Al3+ ions has minimal impact on the linear absorption of KDP crystals, aligning well with the experimental findings. And Al3+ ions could cause a slight shortening of the band gap of KDP crystals. However, these ions could bring significant deformations of O-H bonds. As the concentration of Al3+ ions increase, more O-H bonds linking to PO4 groups are distorted in KDP crystals. As a result, the structural instability could be fast enhanced with increasing the defect concentration. Therefore, high concentrations of Al3+ ions could cause the instability of the crystal structure, which finally affects the laser-induced damage resistance of the KDP crystals. This manuscript contributes to a more comprehensive understanding of the physical mechanisms by which different impurity ions affect the optical properties of KDP crystals.
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Kostman, Todd A., Nathan M. Tarlyn, and Vincent R. Franceschi. "Research note:Autoradiography utilising labelled ascorbic acid reveals biochemical and morphological details in diverse calcium oxalate crystal-forming species." Functional Plant Biology 34, no. 4 (2007): 339. http://dx.doi.org/10.1071/fp06275.
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Many plant species accumulate calcium oxalate crystals in specialised cells called crystal idioblasts. In one species of crystal-forming plants (Pistia stratiotes L.; forming raphide crystals), it has been shown that ascorbic acid is the primary precursor of oxalic acid. The question remains if this is true of other calcium oxalate crystal-forming plants. One way of answering the above question is by examining ascorbic acid as the oxalic acid precursor in diverse species with a variety of crystal types. In this study we tested ascorbic acid as the primary precursor of oxalic acid in four different species, each forming one of the four, thus far, unexamined crystal types: water hyacinth, styloid (and raphide); tomato, crystal sand; winged-bean, prismatic; water lily, astrosclereids with surface prismatic crystals. Pulse–chase feeding of 1-[14C]-ascorbic acid followed by resin embedding, microautoradiography and light microscopy were employed to examine incorporation of label into calcium oxalate crystals. For the species and crystal types studied, ascorbic acid is the primary precursor of oxalic acid and further, oxalic acid is added to crystals in patterns that correlate with the age and type of crystal involved.
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Hidayathullah, A. M., R. S. Samuel, V. Chithambaram, R. Raja, and S. Janarthanan. "Investigations on the synthesis and growth and structural, spectral, optical, mechanical and thermal properties of non-linear optical single crystals of Bis-L-Seriniumoxalate Dihydrate (BLSOD)." Journal of Ovonic Research 19, no. 1 (January 2023): 43–52. http://dx.doi.org/10.15251/jor.2023.191.43.
Full textAbstract:
From the raw materials L-Serine and oxalic acid, the product Bis-LSeriniumoxalatedehydrate(BLSOD) was created. By using a slow evaporation process, the individual BLSOD crystals were produced from aqueous solution. According to single crystal X-ray Diffraction investigations, the structure of the produced crystal is monoclinic. The existence of different functional groups and the chemical environment present in the synthesised material were qualitatively determined through the use of Fourier Transform Infra-Red (FTIR) and proton nuclear magnetic resonance (H1NMR) spectrum studies. The crystal's transparency in the visible and near-infra-red areas was confirmed by UV-Visible-Near infrared and photoluminescence spectrum tests, which also looked at the material's viability for device construction. To determine the crystal's machinability, the mechanical properties of the material were carefully examined using Vicker's hardness research. Thermal investigations such as Thermo gravimetric (TGA) and Differential thermal analysis (DTA) have shown the thermal stability of BLSOD and the phases of weight losses. As a function of frequency and temperature, the dielectric constant and dielectric loss of grown crystals were determined. The Kurtz-Perry powder test was used to check both the second harmonic generation (SHG) and then the NLO property of the material.