33 research outputs found
Ammonothermal Synthesis and Crystal Growth of the Chainâtype Oxonitridosilicate Ca1+xY1âxSiN3âxOx (x > 0)
The oxonitridosilicate Ca1+xY1âxSiN3âxOx (x > 0) was synthesized in customâbuilt highâtemperature autoclaves starting from CaH2, intermetallic YSi and NaN3 using supercritical ammonia as solvent at a maximum pressure of 140 MPa and temperature of 1070 K. In situ formed NaNH2 acts as ammonobasic mineralizer and increases the solubility of the other starting materials. Air and moisture sensitive rodâshaped single crystals of the title compound with length of up to 200 ÎŒm were obtained. The crystal structure was solved and refined by singleâcrystal Xâray diffraction. The results are supported by powder Xâray diffraction, energy dispersive Xâray spectroscopy and lattice energy (MAPLE) calculations. Ca1+xY1âxSiN3âxOx (x > 0) is isostructural to Ca2PN3 and Eu2SiN3 and crystallizes in the orthorhombic space group Cmce (no. 64) with a = 5.331(2), b = 10.341(4), c = 11.248(4) Ă
and Z = 8 (R1 = 0.0257, wR2 = 0.0447) and contains infinite zweier single chains running along [100] which are built up from corner sharing Si(N,O)4 tetrahedra
Crystalline Nitridophosphates by Ammonothermal Synthesis
Nitridophosphates are a wellâstudied class of compounds with high structural diversity. However, their synthesis is quite challenging, particularly due to the limited thermal stability of starting materials like P3N5. Typically, it requires even highâpressure techniques (e.g. multianvil) in most cases. Herein, we establish the ammonothermal method as a versatile synthetic tool to access nitridophosphates with different degrees of condensation. αâLi10P4N10, ÎČâLi10P4N10, Li18P6N16, Ca2PN3, SrP8N14, and LiPN2 were synthesized in supercritical NH3 at temperatures and pressures up to 1070â
K and 200â
MPa employing ammonobasic conditions. The products were analyzed by powder Xâray diffraction, energy dispersive Xâray spectroscopy, and FTIR spectroscopy. Moreover, we established red phosphorus as a starting material for nitridophosphate synthesis instead of commonly used and not readily available precursors, such as P3N5. This opens a promising preparative access to the emerging compound class of nitridophosphates
Sr3P3N7: Complementary Approach by Ammonothermal and HighâPressure Syntheses
Nitridophosphates exhibit an intriguing structural diversity with different structural motifs, for example, chains, layers or frameworks. In this contribution the novel nitridophosphate Sr3P3N7 with unprecedented dreier double chains is presented. Crystalline powders were synthesized using the ammonothermal method, while single crystals were obtained by a highâpressure multianvil technique. The crystal structure of Sr3P3N7 was solved and refined from singleâcrystal Xâray diffraction and confirmed by powder Xâray methods. Sr3P3N7 crystallizes in monoclinic space group P 2/c . Energyâdispersive Xâray and Fourierâtransformed infrared spectroscopy were conducted to confirm the chemical composition, as well as the absence of NHx functionality. The optical band gap was estimated to be 4.4â
eV using diffuse reflectance UV/Vis spectroscopy. Upon doping with Eu2+, Sr3P3N7 shows a broad deepâred to infrared emission (λem=681â
nm, fwhmâ3402â
cmâ1) with an internal quantum efficiency of 42â%
Ammonothermal Synthesis of Ba2PO3N â An Oxonitridophosphate with NonâCondensed PO3N Tetrahedra
The orthoâoxonitridophosphate Ba2PO3N was synthesized under ammonobasic conditions (T = 1070 K, p = 120 MPa) in customâbuilt highâtemperature autoclaves, starting from red phosphorus, BaO, NaN3 and KOH. Thus, single crystals of up to several hundred ”m were obtained, which were used for singleâcrystal Xâray diffraction. Ba2PO3N [Pnma (no. 62), a = 7.596(2), b = 5.796(1), c = 10.212(3) Ă
, Z = 4] crystallizes in the ÎČâK2SO4 structure type with nonâcondensed [PO3N]4â ions and is isotypic to its lighter homologues EA2PO3N (EA = Ca, Sr). Powder Xâray diffraction, energy dispersive Xâray and Fourier Transformed Infrared spectroscopy corroborate the crystal structure. The optical band gap was determined by means of diffuse reflectance UV/Vis spectroscopy to be 4.3 eV. Eu2+ doped samples show green luminescence (λem = 534 nm, fwhm = 85 nm/2961 cmâ1) when irradiated with UV light (λexc = 420 nm). However, Ba2PO3N:Eu2+ shows strong thermal quenching, even at room temperature
The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe
Journal of Applied Oral Science
p.566-571OBJECTIVES: The aim of this study was to evaluate the influence of the contact of two lipsticks, one with common fixer and one with ultra fixer, on the color of a composite resin immediately, 30 min and 24 h after photoactivation.
MATERIAL AND METHODS: Ninety specimens were prepared with a composite resin, Filtek-Z350. Specimens were polished and divided into 9 groups (n=10) according to time elapsed after photoactivation (A- immediately; B- 30 min; C- 24 h) and the contact with lipstick (UF- lipstick with ultra fixer; F- lipstick with common fixer). The control group was represented by specimens that did not have any contact with lipstick (C- without lipstick). Color measurements of the specimens were carried out using a spectrophotometer (Easyshade - CIE L* a* b* system). For UF and F groups, the baseline color of the specimens was measured immediately before pigmentation and the lipsticks were applied dry after 1 hour. The excess lipstick was removed with absorbent paper and final color checking was performed, including the control group. Differences between the final and baseline color measurements were calculated and data were analyzed statistically by the Kruskal-Wallis test at 5%.
RESULTS: The means between the differences of color values were: AUF: 16.0; AF: 12.4; AC: 1.07; BUF: 9.51; BF: 8.3; BC: 0.91; CUF: 17.7; CF: 12.41; CC: 0.82.
CONCLUSION: Groups where lipstick was applied showed greater staining than the control group at the three evaluation times. The lipstick with ultra fixer stained more than the lipstick with common fixer. Time elapsed between photoactivation and contact with lipstick had a similar influence on the groups that received lipstick application
First Reported Use of the Faxitron LOCalizer (TM) Radiofrequency Identification (RFID) System in Europe - Feasibility Trial, Surgical Guide and Review for Non-palpable Breast Lesions
Background/Aim: The problem of adequately marking any given lesion within a breast surgical site is commonly solved by introducing a titanium clip. However, clip dislocation and/or stereotactic hook-wire dislocation are common problems. An ideal solution would be a clip that can be easily found without the use of stereotactic intervention. This work reviews the available data on radiofrequency identification devices (RFID) in breast surgery, reports initial experience data in Europe and discusses surgical pitfalls, advantages and disadvantages. Patients and Methods: This study represents a single center, consecutively recruited, initiation trial with subsequent surgeon questionnaire for the first institution in Europe to report Faxitron LOCalizer (TM) chip data. Four patients with non-palpable tumors were marked with the system and were correlated via mammography, pre- and intra-operative ultrasound and pathology. Data were then compared to available literature and a literature review was added. Results: The four patients marked with this RFID system, displayed a 100% success location rate at a 0% complication rate. Surgeons evaluated the new system as being safe to use and only slightly more difficult to place compared to a standard clip. A significant improvement in ultrasound localization and intraoperative localization was also reported for the LOCalizer (TM) system when compared to a standard titanium clip. Conclusion: This trial added a small number of consecutively recruited patients to an existing number of available data, resulting in a total of 121 evaluated and reviewed Faxitron LOCalizer (TM) marked nonpalpable in-breast lesions worldwide