Amounts Of AgI Research Articles

Ionic conductivity in nanoporous composites SiO 2/AgI

In this work, porous silicate glasses were mixed with an ionic conductor AgI to obtain SiO 2/AgI composites. The porous glasses were either commercial Vycor glass (VPG) from Corning or synthesised from phase separated SiO 2–B 2O 3–Na 2O glasses. Depending upon the elaboration process, glasses with different pore sizes were obtained (4, 20 and 40 nm). Composites comprising different amounts of AgI were prepared by heating above the melting point of AgI. SEM characterisation of the obtained composites indicated that heat treatment induced an increase in the pore sizes. The conductivity of the composites was measured by impedance spectroscopy. The maximum conductivity, twice as large as that of pure AgI, was obtained for the 50AgI/50VPG composite, i.e. that comprising the glasses with the smallest pores.

A Facile Preparation ofN,N-Disilylbenzylamines from Benzylic Chlorides Using AgI/LiN(SiMe3)2System

Abstract The reaction of benzylic chlorides with lithium N,N-bis(trimethylsilyl)amide in the presence of AgI gives the corresponding N,N-disilylbenzylamines in good to excellent yields. The amounts of AgI used are highly dependent on the substrates.

Determination of frost hardiness of Eucalyptus using the electrical conductivity of diffusate in conjunction with a freezing chamber

An electrical conductivity method for determining frost hardiness of tissue discs punched from Eucalyptus leaves is described. Samples were exposed to convective heat loss in an air-filled chamber. Rates of cooling and desired frost temperatures were electronically controlled and maintained. Supercooling of tissue was effectively eliminated by addition of small amounts of AgI and water. Conductivity of diffusate was measured as a means of quantifying tissue damage following frost. Relative conductivity was determined with reference to subsequent measurements following heating the discs to 70 °C which resulted in maximum conductivity. Exposure of leaf discs to temperatures below the lethal temperature for these species (<−10 °C) resulted in similar maximum conductivity readings. The technique is evaluated to assess its potential to distinguish small differences in frost hardiness caused by genotype and environment. For both E. delegatensis and E. nitens there was no significant difference in frost hardiness expressed in terms of mean lethal temperature when comparing leaf discs with frosting whole seedlings.

High-pressure phase diagram of silver mercury iodide (Ag2HgI4).

Differential scanning calorimetry has been used to study the phase diagram of ${\mathrm{Ag}}_{2}$${\mathrm{HgI}}_{4}$ in the range up to 1 GPa and from 278 to 440 K. Stoichiometric samples were prepared by a solid-state reaction which gives pure ${\mathrm{Ag}}_{2}$${\mathrm{HgI}}_{4}$, while previous high-pressure studies have been on samples prepared by precipitation, a technique where the presence of minor amounts of AgI as impurity hardly can be avoided. The phase diagram is characterized by two triple points: 0.477 GPa, 328.5 K and 0.74 GPa, 400.5 K. At ambient temperature a transition between the ordered phases occurs at 0.62 GPa when the pressure is increased but at 0.47 GPa when the pressure is decreased. In both cases the transition enthalpy is strongly temperature dependent, indicating that there is either a triple point or a critical point near 270 K. The temperature of the order-disorder transition between the \ensuremath{\beta} and \ensuremath{\alpha} phases increases from 325 K at normal pressure to a maximum of 334 K at 0.42 GPa. The enthalpy of the \ensuremath{\beta}\ensuremath{\rightleftarrows}\ensuremath{\alpha} transition is 8.5 kJ/mol at normal pressure and 6.2 kJ/mol in the range 0.0001\char21{}0.477 GPa. The enthalpy of the \ensuremath{\gamma}\ensuremath{\rightleftarrows}\ensuremath{\alpha} order-disorder transition increases from 1.3 kJ/mol at 0.477 GPa to 6.8 kJ/mol at 0.74 GPa. Perhaps the most remarkable features of this phase diagram concern the transition of the disordered \ensuremath{\alpha} phase to other disordered high-temperature phases. At normal pressure the transition enthalpy is 11.5 KJ/mol at 425 K. The transition temperature has a maximum of 428 K at about 0.045 GPa. At higher pressures the transition changes its character, and it is clearly second order from, say, 0.16 GPa to a singularity point (minimum) at 0.474 GPa and 382 K. Beyond this point the transition enthalpy increases linearly from zero up to 11.9 kJ/mol at 0.74 GPa.

Numerical Simulation of Ice-Phase Convective Cloud Seeding

Abstract A two-dimensional time-dependent cloud model which covers a region 19.2 km × 19.2 km in the x and z directions with 200 m grid intervals, has been used to simulate silver iodide (AgI) seeding effects on strong convective clouds. The model is a set of conservation equations for momentum, energy and mass (air and water contents). One extra conservation equation is applied to trace the seeding agent which advects and diffuses along the flow field and interacts with the supercooled cloud fields. Contact and deposition nucleation are simulated. Only inertial impact and Brownian collection are considered as possible mechanisms for contact nucleation. Most of the AgI particles work as deposition or sorption nuclei in this study. Three different soundings are tested. Most of the effort is used in testing sounding H1, from Miles City, Montana, 29 July 1975. Seeding at a different place (see H1/P1), at a different time (case H1/T1), and with different amounts of AgI (cases H1/M1 and H1/M2) are simulated. T...