Different Types Of Crystals Research Articles

DoubleTES detectors to investigate the CRESST low energy background: results from above-ground prototypes

In recent times, the sensitivity of low-mass direct dark matter searches has been limited by unknown low energy backgrounds close to the energy threshold of the experiments known as the low energy excess (LEE). The CRESST experiment utilises advanced cryogenic detectors constructed with different types of crystals equipped with Transition Edge Sensors (TESs) to measure signals of nuclear recoils induced by the scattering of dark matter particles in the detector. In CRESST, this low energy background manifests itself as a steeply rising population of events below 200 eV. A novel detector design named doubleTES using two identical TESs on the target crystal was studied to investigate the hypothesis that the events are sensor-related. We present the first results from two such modules, demonstrating their ability to differentiate between events originating from the crystal’s bulk and those occurring in the sensor or in its close proximity.

Two pressure-induced molecular superconductors with different types of crystal and electronic structures derived from an unsymmetrical tetrachalcogenafulvalene

Abstract We newly synthesized an organic donor molecule ETTM-STF (ethylenedithio(trimethylene)diselenadithiafulvalene), a molecular hybrid of HMTTF (hexamethylenetetrathiafulvalene) and BETS (bis(ethylenedithio)tetraselenafulvalene). Electrochemical oxidation of ETTM-STF provided two cation radical salts, (ETTM-STF)2Au(CN)2 and (ETTM-STF)2BF4. Crystal structure of the Au(CN)2 salt is characterized by a monolayer structure based on dimerized donor molecules. On the other hand, the BF4 salt shows a bilayer structure that is composed of two crystallographically independent conducting layers with different types of electronic structures. At ambient pressure, the Au(CN)2 salt is a Mott insulator and the BF4 salt undergoes a metal–nonmetal transition where the two types of conducting layers exhibit different behavior. Application of pressure suppressed the nonconducting behavior and induced a superconducting state in the Au(CN)2 salt (Tc = 3.4 K at 9.5 kbar) and in the BF4 salt (Tc = 6.8 K at 8 kbar).

Glows to Breakdown Characteristic of ZnO Crystal Growth Using Electric Current Heating Method

Zinc oxide (ZnO) crystals form are various applications could be created like in manufacturing ultraviolet laser and photodetectors. Zinc oxide (ZnO) crystals are synthesized by applying electric current on ZnO ceramic bar which are made using powder metallurgy method. By using Scanning Electron Microscope (SEM) and X-Ray Diffractometer (XRD) could be characterized of ZnO sintered bars easily. The different types of crystal are produced such as polygonal, broken stick, flowers, trunks and many more when applied the DC heating until the sample of ZnO will be glows and breaks apart. The loads or pressure and heating method to the sample of ZnO will be affected to the types of crystal growth. The optimum load is 3 metric tonne and will ease the ignition during DC heating due to less porosity of the samples.

Characterization of Different Types of Crystallization from Cocoa Butter by Using Terahertz Spectroscopy

Three different cocoa butter polymorphs have been determined by X-ray diffraction (XRD) and terahertz spectroscopy in the range of 0–11 THz. Specific procedures to produce different types of crystallization were detailed. The results from XRD analysis showed that the three polymorphic forms of cocoa butter were α, β′ (III), and β (V) forms. Terahertz spectroscopy showed different features according to different types of crystallization forms. An observable sharp peak at 6.80 THz can be detected from β (V) type and original samples, whilst α type presented the broad peak at this frequency, respectively. Peaks at 4.25 THz and 5.21 THz were detected in β type (V) form, whilst no noticeable peaks were observed from other samples at those frequencies. This study innovatively showed a great potential to apply terahertz spectroscopy to control the tempering during chocolate manufacturing.

A user-friendly plug-and-play cyclic olefin copolymer-based microfluidic chip for room-temperature, fixed-target serial crystallography.

Over the past two decades, serial X-ray crystallography has enabled the structure determination of a wide range of proteins. With the advent of X-ray free-electron lasers (XFELs), ever-smaller crystals have yielded high-resolution diffraction and structure determination. A crucial need to continue advancement is the efficient delivery of fragile and micrometre-sized crystals to the X-ray beam intersection. This paper presents an improved design of an all-polymer microfluidic `chip' for room-temperature fixed-target serial crystallography that can be tailored to broadly meet the needs of users at either synchrotron or XFEL light sources. The chips are designed to be customized around different types of crystals and offer users a friendly, quick, convenient, ultra-low-cost and robust sample-delivery platform. Compared with the previous iteration of the chip [Gilbile et al. (2021), Lab Chip, 21, 4831-4845], the new design eliminates cleanroom fabrication. It has a larger imaging area to volume, while maintaining crystal hydration stability for both in situ crystallization or direct crystal slurry loading. Crystals of two model proteins, lysozyme and thaumatin, were used to validate the effectiveness of the design at both synchrotron (lysozyme and thaumatin) and XFEL (lysozyme only) facilities, yielding complete data sets with resolutions of 1.42, 1.48 and 1.70 Å, respectively. Overall, the improved chip design, ease of fabrication and high modifiability create a powerful, all-around sample-delivery tool that structural biologists can quickly adopt, especially in cases of limited sample volume and small, fragile crystals.

Reductive C-O Cleavage of Ethereal Solvents and 18-Crown-6 in Ln(NR2)3/KC8 Reactions (R = SiMe3).

The high reactivity accessible from the reduction of the tris(amide) complexes Ln(NR2)3 (R = SiMe3) with potassium graphite in the presence of a variety of ethers is demonstrated by crystal structures of six different types of products of C-O bond cleavage reactions with Ln = Y, Ho, Er, and Lu. Specifically, 1,2-dimethoxyethane (DME) can be cleaved in Ln(NR2)3/KC8 reactions as shown by three different types of crystals: [K (crypt)][(R2N)3Y(OCH2CH2OCH3)], 1-Y, [(R2N)2Y(μ-OCH2CH2OCH3-κO,κO')]2, 2-Y, and [K2(18-c-6)3]{[(R2N)3Lu]2[(μ-OCH2CH2O)]}, 3-Lu (18-c-6 = 18-crown-6; crypt = 2.2.2-cryptand). THF can be ring opened by the Y(NR2)3/KC8 reaction system, as shown by crystals of the butoxide, [K(crypt)][(R2N)3Y(OCH2CH2CH2CH3)], 4-Y. The cyclic ether, oxetane, OC3H6, ring opens in Ln(NR2)3/KC8 reactions to form crystals of the propoxide, [K(18-c-6)(OC3H6)][(R2N)3Ln(OCH2CH2CH3)], 5-Ln, for Ln = Ho and Er. In Et2O, the Y(NR2)3/KC8 reactions do not attack the solvent, but C-O cleavage of 18-c-6 is observed to form {[(R2N)2]Y[μ-η1:η1-O2(C10H20O4)K]}2, 6-Y. These Ln(NR2)3/KC8 C-O cleavage reactions are typically accompanied by C-H bond activation reactions, which form cyclometalates such as [K(crypt)]{(R2N)2Ln[N(SiMe3)(SiMe2CH2)-κC,κN]}, 7-Ln (Ln = Y, Ho, Er), and [K(18-c-6)]{(R2N)2Y[N(SiMe3)(SiMe2CH2)-κC,κN]}, 8-Y, which are common decomposition products of Ln(NR2)3 reactions. In addition, in this study, the hydride complex, [K(18-c-6)][(R2N)3YH], 9-Y, was isolated. NMR analysis indicates that the yttrium reactions form mixtures that consistently contain the yttrium cyclometalates 7-Y and 8-Y as major components. These results show the diversity of available reaction pathways for the Ln(NR2)3/KC8 system and highlight the inherent difficulties in isolating Ln(II) complexes containing the [Ln(NR2)3]1- anion.

Korelasi antara jenis pakan komersial dengan jenis kristal pada kasus kucing flutd (feline lower urinary tract disease) di rumah sakit hewan dinas peternakan Jawa Timur

Feline lower urinary tract disease (FLUTD) is a term used to describe various causes of lower urinary tract disorders in cats which include idiopathic, urolithiasis, urinary tract infections, anatomical and neurological disorders. Use of commercial feed is one of the causes of Flutd formation. This study was to determine the correlation between commercial feed types and crystal types in the case of FLUTD cats at the Animal Hospital of East Java Province. The sample is primary data obtained directly by collection of fresh urine and through interviews with animal owners. As many as 30 fresh urine samples were sedimented and then observed under a microscope. The results of observations of urine sedimentation with a microscope showed that 16 cats had crystals in their urine. The highest percentage of struvite crystals was 12 cats (40%). Meanwhile, in 14 cats (46.7%) no crystals were found in the urine. It is known that the sensitivity of the urine sedimentation test is 64% and the specificity is 97%. There are different types of crystals in commercial feed with the same brand. the same brand of commercial feed can produce different types of crystals. This is due to many other factors that trigger the formation of crystallization. The urine sedimentation test is very accurate to detect cases of FLUTD and crystals in the urine

Dual-energy computed tomography in crystalline arthritis: knowns and unknowns.

To give an overview of what can reasonably be considered as known about dual-energy computed tomography (DECT) in crystal-related arthropathies, and what still needs to be explored. Recent studies suggest an overall superiority of DECT over ultrasound in gout in terms of sensitivity (89 vs. 84%) and specificity (91 vs. 84%), except in early disease. Additional studies are needed to optimize DECT postprocessing settings in order to improve the specificity of the technique and eliminate all artifacts. Evidence has been controversial concerning DECT's ability to detect monosodium urate (MSU) crystal deposits on vessel walls, or whether or not MSU-coded plaques are artifacts. DECT can be used to monitor MSU crystal depletion during urate-lowering treatment; MSU crystal volume is associated with cardiovascular risk and disease activity. There are some reports on calcium-containing crystal deposition diseases (calcium pyrophosphate and basic calcium phosphate) demonstrating that DECT can characterize and discriminate between the different types of crystals. Our knowledge about the use of DECT in crystal-related arthropathies continues to expand. Some unknowns have been clarified but there's still lots to learn, particularly concerning gout management and the potential use of DECT in calcium-containing crystal-related arthropathies.

Effect of iron on the microstructure of basalt glass‐ceramics obtained by the petrurgic method

AbstractBasalt glasses may form glass‐ceramic materials upon a thermal treatment (TT) if the Fe2O3/FeO ratio is greater than 0.5. In this work, a Serra Geral Formation basalt was used to produce different glass‐ceramic materials by changing its chemical composition, removing Fe2O3 via magnetic separation and adding 20 wt% Fe2O3. Glass‐ceramics were prepared by melting at 1500°C, followed by a crystallization plateau at 950°C. This petrurgic TT yields dendritic structures upon surface crystallization. With the increase of the iron content, crystallization was more pronounced, as observed in thermal analysis results and optical/scanning electron microscopy. The microstructure analysis shows that these glass‐ceramics exhibit at least two different types of crystallization. On the surface, the predominant crystallization was dendritic, while in bulk, crystallization occurred in the form of randomly distributed submicrometric spheroid crystals.

BaAl2Si2O8 polymorphs and a novel reversible transition of BaAlF5 in supercooled oxyfluoride aluminosilicate liquids

Crystallization plays a critical role in realizing the functionalization of glass materials. However, it is imperative to understand the microscopic mechanism of both the formation and the phase transitions of nanocrystals during heat processes. Here, in the as-prepared SiO2-Al2O3-BaF2-Na2O glass, we studied the polymorphic phase transition of BaAl2Si2O8 during heating-cooling circles, and a novel reversible transformation is found by serendipity. Using differential scanning calorimetry (DSC), we observed an endothermic event around 1047 K during heating at 20 K/min to 1173 K, and an exotherm event at 1024 K during the subsequent cooling. Based on the X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM), the reversible process was attributed to the transition between two morphs of BaAlF5 nano-crystal. Na2O introduced in the studied glass system promotes the transformation between hexacelsian (Hexagonal) and celsian (Monoclinic). The results also show the formation of different types of crystals, such as, BaF2, Na5Al3F14 and BaAlF5 etc.

Isolation of Iranian Bacillus thuringiensis strains and characterization of lepidopteran-active cry genes

BackgroundInsecticidal crystal proteins (encoded by cry genes) produced by Bacillus thuringiensis (Bt) are fatal for insects of different orders such as Lepidoptera. The genes that encoded these crystal proteins can be detected on plasmids and chromosomal DNA and show different types in various strains. Therefore, the objective of this study was to determine molecular characteristics of Iranian Bt strains as well as their toxicity against Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae).ResultsThe collection sites included fields, gardens, and desert and semi-desert areas in 8 provinces of Iran. For crystal formation, each isolate was cultured in T3 medium. The results showed that the Bt isolates produced different types of crystals including spherical (73.33%), bipyramidal (53.33%), irregular (40%), cubical (33.33%), and elliptical (13.33%). Plasmid DNA extraction was performed and showed that most of the strains exhibited similar pattern in the number and the size of the plasmid bands to those of Bt kurstaki (Btk). Some specific primers were used for PCR amplification to distinguish different crystal genes including cry1 (A, C, and D) and cry2A (a and b). The primers related to cry1D and cry2Aa1 genes produced no amplicons. The results revealed that the most abundant gene was cry1-type. All strains analyzed for the cry2Ab2 gene presented unexpected bands. Electrophoretic profile of the protein crystals showed bands with different diversity in number, and size ranged from about 16 to 140 KDa. The bioassay result of some more toxic strains exhibited that the pathogenicity of 1019 was higher than the rest, even the reference strain, Btk. However, the toxicity of other strains was the same as Btk. According to the phylogenetic tree, 1019 was located in the same group with Bt subspecies coreanensis, Bt subspecies indiana and Bt subspecies tolworthi.ConclusionsThe investigated Iranian strains had the lepidopteran-active cry genes. The strains with the same toxicity to E. kuehniella had various cry genes, plasmid, and crystal protein profiles and vice versa. Therefore, characterization of cry genes of native strains could lead to access potent isolates as biocontrol agents against native insect pests.

English

Plants are widely used in traditional medicine, but could be detrimental to patients, due to the presence of some harmful substances such as calcium oxalate (CaOx) C2CaO4 crystals. The presence, morphology and distribution of CaOx crystals were investigated in 60 wild, herbal plant species from the Al Qussim Region, Saudi Arabia. This was done via light microscopy of transverse sections of stems and leaves using light microscopy. Different types of CaOx crystals were found in only 24 of the plant species studied, the rest had no CaOx crystals. The stems of 12 plant species under study contained different types of CaOx crystals, with crystal sand being the most common. In the leaves of four plant species, druses and solitary crystals were the most frequently found types. In addition, eight species had different types of crystals in their respective stems and leaves. Rumex vesicarius had the most crystals in both its stems and leaves from all investigated species, followed by Asphodelus tenuifolius. Key words: Ca-oxalate crystals, light microscope, plant leaves, stems, Al Qussim Region.

Comparative pharmacognostic study of leaves, stems, and roots of Urera baccifera (L.) Gaudich. ex Wedd.

The quality control of drugs is necessary to guaranty the safety and efficacy of natural products. In this sense, the present investigation is led to compare the pharmacognostic parameters and preliminary phytochemical composition of the leaves, stems and roots of Urera baccifera, a medicinal plant with gastroprotective, anti-inflammatory, analgesic, and antimicrobial activities. The morphological characteristics and physicochemical parameters were evaluated for three organs, according to well-established methods for vegetal drugs. In addition, phytochemical screening was made. In microscopical analysis, different types of crystals were observed in each organ. Also, the leaves showed the highest percentage of total ashes and soluble constituents. Water was the better extraction solvent. The micromorphological characteristics and physicochemical parameters were reported for the first time for this species. The hydroalcoholic extract of three organs showed the presence of lactones, triterpenes, flavonoids, amino acids, phenols and sugar reducing. Based on the results, the leaves are proposed for the development of future phyto drugs from U. baccifera, in contrast with the ethnomedical information, where the roots are used.

Pathological crystal imaging with single-shot computational polarized light microscopy.

Pathological crystal identification is routinely practiced in rheumatology for diagnosing arthritis disease such as gout, and relies on polarized light microscopy as the gold standard method used by medical professionals. Here, we present a single-shot computational polarized light microscopy method that reconstructs the transmittance, retardance and slow-axis orientation of a birefringent sample using a single image captured with a pixelated-polarizer camera. This method is fast, simple-to-operate and compatible with all the existing standard microscopes without extensive or costly modifications. We demonstrated the success of our method by imaging three different types of crystals found in synovial fluid and reconstructed the birefringence information of these samples using a single image, without being affected by the orientation of individual crystals within the sample field-of-view. We believe this technique will provide improved sensitivity, specificity and speed, all at low cost, for clinical diagnosis of crystals found in synovial fluid and other bodily fluids.

Cellulose nanocrystals in aqueous suspensions: rheology of lyotropic chiral liquid crystals

A thorough rheological study of the behavior of cellulose nanocrystals (CNC) in water was undertaken, focusing on the main characteristics of rod-like suspensions that allign under flow and can display liquid crystal behavior at rest, in at least a range of concentrations. The effect of adding a dispersing agent (gum arabic, GA) to the suspension was analyzed, and different surface treatments were also performed on the CNC using TEMPO, chloro(dodecyl)dimethylsilane and trimethoxysilyl propylmethacrylate, named as TCNC, DCNC and MCNC respectively. The CNC, TCNC and the suspensions prepared with added GA formed stable suspensions with a concentration range in which isotropic and anisotropic (self-organized) phases coexisted in equilibrium. On the other hand, the aqueous suspensions of the two silanized CNCs only displayed flow-induced ordering, with a similar type of rheological behavior to the other nanocrystal suspensions, although with obvious quantitative differences. These latter ones were not stable suspensions and precipitated after a few hours of rest. The rheological tests included steady shear, dynamic oscillations and start-up of steady shear that were performed for all the nanocrystals suspensions prepared at different concentrations. Differences observed were related to the crystals surface modifications or addition of the dispersing agent. A persistent periodic oscillation of the viscosity was measured in the start-up of steady shear tests and the periods of the oscillations were determined and related to the different types of crystals considered.

Active crystals on a sphere.

Two-dimensional crystals on curved manifolds exhibit nontrivial defect structures. Here we consider "active crystals" on a sphere, which are composed of self-propelled colloidal particles. Our work is based on a phase-field-crystal-type model that involves a density and a polarization field on the sphere. Depending on the strength of the self-propulsion, three different types of crystals are found: a static crystal, a self-spinning "vortex-vortex" crystal containing two vortical poles of the local velocity, and a self-translating "source-sink" crystal with a source pole where crystallization occurs and a sink pole where the active crystal melts. These different crystalline states as well as their defects are studied theoretically here and can in principle be confirmed in experiments.

Synthesis, structural characterization and catalytic potential of oxidovanadium(IV) and dioxidovanadium(V) complexes with thiazole-derived NNN-donor ligand

Reaction between the tridentate NNN donor ligand, (E)-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)benzo[d]thiazole (HL), and V2O5 in ethanol gave a new vanadium(V) complex, [VO2L] (1), while the similar reaction by using [VIVO(acac)2] as the metal source gave two different types of crystals related to compounds [VO2L] (1) and [VIVO(acac)L] (2). The molecular structures of the complexes were determined by single-crystal X-ray diffraction and spectroscopic characterization was carried out by means of FT-IR, UV–vis and NMR experiments as well as elemental analysis. The oxidovanadium(IV) and dioxidovanadium(V) species were used as catalyst precursors for olefin oxidation in the presence of hydrogen peroxide (H2O2) as an oxidant. Under similar experimental conditions, the presence of 1 resulted in higher oxidation conversion than 2.

3,4-Lutidinium salts with the diiodidoaurate(I) anion: structure of [(3,4-lut)2H]+·[AuI2]−and of two polymorphs of [(3,4-lut)2H+]2·[AuI2]−·I−

Reactions between potassium tetraiodidoaurate(III) and pyridine (py, C5H5N) or 3,4-lutidine (3,4-dimethylpyridine, 3,4-lut, C7H9N) were tested as possible sources of azaaromatic complexes of gold(III) iodide, but all identifiable products contained gold(I). The previously known structure dipyridinegold(I) diiodidoaurate(I), [Au(py)2]+·[AuI2]-, (3) [Adams et al. (1982). Z. Anorg. Allg. Chem. 485, 81-91], was redetermined at 100 K. The reactions with 3,4-lutidine gave three different types of crystal in small quantities. 3,4-Dimethylpyridine-3,4-dimethylpyridinium diiodidoaurate(I), [(3,4-lut)2H]+·[AuI2]-, (1), consists of an [AuI2]- anion on a general position and two [(3,4-lut)2H]+ cations across twofold axes. Bis(3,4-dimethylpyridine-3,4-dimethylpyridinium) diiodidoaurate(I) iodide, [(3,4-lut)2H+]2·[AuI2]-·I-, (2), crystallizes as two polymorphs, each forming pseudosymmetric inversion twins, in the space groups P21 and Pc (but resembling P21/m and P2/c), respectively. These are essentially identical layer structures differing only in their stacking patterns and thus might be regarded as polytypes.

Terahertz Non-Contact Monitoring of Cocoa Butter in Chocolate

Chocolate is widely enjoyed in many sweets and foods all over the world. In cocoa butter, fatty acids combine together and give cocoa butter 6 different types of crystals: γ, α, β’(III), β’(IV), β(V) and β(VI). In the industry, the β(V) form that is required, is metastable and gives chocolate its marketable properties. The β(VI) form is also stable but not desirable, because of fat bloom. The objective of this study is to characterize these polytypes by terahertz(THz) spectroscopy. THz spectroscopy is expected to be a new tool in food industry, as THz energy corresponds to collective molecular macro-vibrations. Two chocolates from different factories were inspected with optical microscope, X-ray diffraction (XRD) and THz spectroscopy. Optical microscope showed different surface aspects, XRD showed the same species in the two brands and THz spectroscopy showed different features. These differences may be due to fatty acids combination of chocolate.

Influence the Temperature on Optical Properties for (5PCH) Liquid Crystal

Liquid crystals are state of substance possesses characteristics between traditional liquid and crystallization. For instance, perhaps liquid crystal away similar to the crystals. There are different types of crystal in the liquid phase. In this study, used nematic liquid crystals type (5PCH) and wavelength (632.8nm) for find the temperature effect on optical properties. This study shows the direct proportionality between the temperature and the absorptance (A), reflectance (R) , absorption coefficient (a), and the extinction coefficient (k), from one side and the indirect proportionality between the temperature with the transmittance(T).