• Journal of the Korean Chemical Society
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• v.18 no.2
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• pp.126-131
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• 1974

Trioctylamine-and tricaprylylmethylammonium chloride-tungstate salts have been prepared by solvent extraction from the sodium tungstate solution of various acidities(pH = 2, 4, 6). The molecular weights of the amine-tungstate salts thus obtained could be cryoscopically measured in benzene by means of a home-built Wheatstone bridge utilizing thermistor with sensitivity of 1/$4000^{\circ}C$. The cryoscopic data along with the results of chemical analysis and infrared spectra of the salts indicate that the amine-tungstates prepared at pH = 2 and 4 are all metatungstate whereas the salt obtained at pH = 6 is an unknown form quite different from the expected paratungstate.R = 0.14. By hydrogen bonding a guanidyl nitrogen of a sulfaguanidine molecule is linked to the sulfonyl oxygens of the other molecules indirectly through two different water molecules. The role of water molecule is both a .
nor and an acceptor in hydrogen-bonding formation and these hydrogen bonds are tetrahedrally o？ented. The hydrogen-bonding networks form infinite molecular layers parallel to (001) plane.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.578-583
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• 2017

This paper presents a 3D touch pad technology that uses force touch sensors as a next-generation method for mobile applications. 3D touch technology requires detecting the location and pressure of touches simultaneously, as well as multi-touch function. We used metal foil strain gauges for the touch recognition sensor and detected the weak touch signals using Wheatstone bridge circuit at each strain gauge sensor. We also developed a touch recognition system that amplifies touch signals, converts them to digital data through a microprocessor, and displays the data on a screen. In software, we designed a touch recognition algorithm with C code, which is capable of recognizing two-point touch and differentiating touch pressures. We carried out a successful experiment to display two touch signals on a screen with different forces and locations.