the structure of the nonaaquayttrium (iii) bromate, [y(h2o)9](bro3)3, at low temperature (100 k) has been studied by means of single-crystal x-ray diffraction. crystallography shows a hexagonal unit cell, space group p63/mmc (no. 194) with z = 2, a = b = 11.7104(11) å, c = 6.6259(5) å and v = 786.90(12) å3 at 100 k. the hydrated trivalent yttrium(iii) ion forms a tricapped trigonal prism, in wh...

in this paper, design and construction of a tactile sensor for measuring contact-force is presented. mechanism of measuring contact-force in this tactile sensor is based on impedance changing of piezoelectric crystal and voltage of different points in circuit as a result of applying force on the crystal. by considering a specific point in the circuit and recording the changes of its voltage, ma...

background: similar to the thermoluminescence (tl) spectra, the optical parameters variations can also be used in tl crystals for dosimetry purposes. these optical parameters can include absorption, transmission and reflection coefficients. materials and methods: single crystals of kbr and kcl which have been used in this research were grown from laboratory grade extra pure precursor powders. c...

TiCl4, ammonia, inorganic salts as raw material, nanometer composite-crystal TiO2 powders were synthesized by two-step chemical method. Precursors were crystallized with different phase and stable composite-crystal TiO2 with anatase and rutile phase was prepared at low temperature. Quantitative control of crystal phase was realized. Remarkable factors includ...

calcium dichloride tetra urea was prepared by the reaction of calcium chloride with urea in aqueous solution. the crystals are monoclinic, a= 7.633, b= 12.45 1, c= 8.118 ?,? = 113.17, z = 4, space group p 2,/a. the crystal structure was determined by single crystal x-ray methods and refined to r= 0.041. the calcium atoms are coordinated to four oxygen atoms of urea and to two chloride ions. the...

This paper deals with the design and fabrication of a quartz-crystal resonator used in a thickness-monitor unit, measuring film thickness in a film-depositing system. A purpose-grown quartz crystal is cut to form the desired wafer. Two gold electrodes are deposited on both surfaces of the wafer to provide electrical contacts. The resonance frequency of the resonator, at room temperature, and th...

the structure of n,n'-bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine, c19h22n2o2, has been studied at low temperature (120k) by means of single-crystal x-ray diffraction. solving the structure shows an orthorhombic unit cell, with p212121 space group, z = 4, a = 6.1046 (4) å, b = 15.8349 (11)å, c = 17.2898 (12) å and v = 1671.3 (2) å3. there are two relatively strong hydrogen bonds (...

Recently, photonic crystals doped with liquid crystal (LC) material havegained much research interest. In this article new ternary one-dimensional photoniccrystal introduced and studied. The liquid crystal layer of 5CB and 5PCH is sandwichedby two dielectric layers. For the first time, we use four structures SiO2/UCF35/CaF2,SiO2/5CB/CaF2, NFK51/UCF35/NPSK53 and NFK51/5CB/NPSK53. The effect ofte...

Introduction:  In  this  study,  we  utilized  the  MCNP4C  Monte  Carlo  code  to  quantitatively  evaluate  the  influence of crystal size and material on intercrystal scatter and parallax effects.   Materials and Methods:  For each of the 5 selected crystals (BGO, LSO, LYSO, LuAP, GSO), transport of  511  keV  photons  originating  from  a  point  source  and  incident  on  the  central  cry...