Abstract: The present application describes a sensor apparatus based on chemically functionalized graphene as the sensing materials. The sensing materials is modified from graphene oxide with unique chemical process to form a group of graphene derivatives, e.g. butylamine, hexylamine, decylamine, dodecylamine, benzylamine etc., to detect volatile and non-volatile compounds, e.g. toluene, ethylacetate, ethanol, acetone, hexane etc. with high sensitivity. Pattern recognition algorithms and methods, e.g. PCA, are coupled with the sensors for detecting and quantifying specific chemical compounds. Methods of using the sensor apparatus in applications such as diagnosis of disease and food quality control are disclosed.

Abstract: A spiral-orifice ceramic filter for metal casting, including spiral channels and two drain openings, where the spiral channels are distributed in a ceramic substrate in a staggered manner. By adoption of the spiral channel structure, molten metal may rotate to generate a centrifugal force while flowing forwards so as to promote separation of inclusions. The spiral-orifice ceramic filter for metal casting includes the following components: 90-95 wt % of MgO, 4-8 wt % of SiO2 and 2-4 wt % of ZrO2. Therefore, the spiral-orifice ceramic filter for metal casting has high strength under normal temperature and optional thermal impact resistance under high temperature, and may tolerate the impact of molten metal at 1700° C. or higher without break. The ceramic substrate and the spiral channel are superficially coated with one layer of functional oxide prepared from CaO.2Al2O3, CaO.6Al2O3, Al2O3, TiO2, or Re2O3.

Abstract: A spiral-orifice ceramic filter for metal casting, including spiral channels and two drain openings, where the spiral channels are distributed in a ceramic substrate in a staggered manner. By adoption of the spiral channel structure, molten metal may rotate to generate a centrifugal force while flowing forwards so as to promote separation of inclusions. The spiral-orifice ceramic filter for metal casting includes the following components: 90-95 wt % of MgO, 4-8 wt % of SiO2 and 2-4 wt % of ZrO2. Therefore, the spiral-orifice ceramic filter for metal casting has high strength under normal temperature and optional thermal impact resistance under high temperature, and may tolerate the impact of molten metal at 1700° C. or higher without break. The ceramic substrate and the spiral channel are superficially coated with one layer of functional oxide prepared from CaO.2Al2O3, CaO.6Al2O3, Al2O3, TiO2, or Re2O3.