Wet Etching Method for Electroless Ni-P Plating of Bi-Te Thermoelectric Element.

In this study, a method for electroless Ni-P plating with excellent adhesion via chemical wet etching to fabricate Bi-Te thermoelectric modules is proposed. The electroless Ni-P plating formed through the proposed method showed excellent adherence without peeling, even under heat treatment of 200 °C for 24 h. Wet etching and electroless Ni-P plating was performed on a Bi-Te thermoelectric module, which showed the excellent bond strength of approximately 10 MPa. The surface roughness of the Bi-Te thermoelectric element was increased significantly by the wet etching process, which secured the adherence of the Ni-P plating by anchoring to this induced surface roughness.

Measurements of major VOCs released into the closed cabin environment of different automobiles under various engine and ventilation scenarios.

Volatile organic compounds (VOCs) in automobile cabins were measured quantitatively to describe their emission characteristics in relation to various idling scenarios using three used automobiles (compact, intermediate sedan, and large sedan) under three different idling conditions ([1] cold engine off and ventilation off, [2] exterior air ventilation with idling warm engine, and [3] internal air recirculation with idling warm engine). The ambient air outside the vehicle was also analyzed as a reference. A total of 24 VOCs (with six functional groups) were selected as target compounds. Accordingly, the concentration of 24 VOC quantified as key target compounds averaged 4.58 ± 3.62 ppb (range: 0.05 (isobutyl alcohol) âˆ¼ 38.2 ppb (formaldehyde)). Moreover, if their concentrations are compared between different automobile operational modes: the 'idling engine' levels (5.24 ± 4.07) was 1.3-5 times higher than the 'engine off' levels (4.09 ± 3.23) across all 3 automobile classes. In summary, automobile in-cabin VOC emissions are highly contingent on changes in engine and ventilation modes.

Characteristics of chlorofluorocarbons (CFCs) emitted from a municipal waste treatment facility.

The emission concentrations of several chlorofluorocarbons (CFCs) were measured from a municipal waste treatment facility (located in Seoul, Republic of Korea) to investigate the emission characteristics of CFCs in the urban environment. To this end, a total of five CFCs (CFC-10, CFC-11, CFC-20, CFC-30, and CFC-113) were analyzed by the thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method. The results of this study indicate that the formation of CFC-11 (8.21 ± 1.68 ppb in spring) and CFC-20 (3.92 ± 3.93 ppb in spring) proceeded very actively within the facility. Moreover, CFC-113 was also found in relatively high concentrations (3.34 ± 1.31 ppb in spring) in the treatment facility. Unlike other CFCs, CFC-10 was observed mainly at ambient (and reference) locations and one point inside the treatment facility. In conclusion, emissions of some important CFCs are a prominent process, as they were measured either frequently or abundantly both in winter and spring. It is further indicated that certain CFCs (like CFC-11 and CFC-30) are subject to highly significant seasonal variations.