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Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is ...

Inha University

Black phosphorus (BP) materials have attracted considerable attention owing to their ultra-sensitive humidity sensing characteristics because of the natural absorption of water (HO) molecules on the BP surface caused by the specific 2D layer-crystalline structure. On the other hand, the BP-based humidity sensor is less repeatable due to the instability of BP with water molecules and the stability of the sensor is reduced. In this study, this limitation of the BP-based humidity sensor was overcome by preparing a BP/graphene hybrid as a novel humidity sensing nanostructure. The BP/graphene interface improved the stability of the humidity sensor after a few weeks with a linear response within the relative humidity (RH) range of 15-70%. The sensor's response/recovery speed of the humidity sensor was extremely fast within few seconds. The response (S) of the humidity sensor based on the BP/graphene hybrid is 43.4% at RH = 70%. The estimated response and recovery time of the sensor is only 9 and 30 seconds at RH = 70% at room temperature. The experimental investigation reveals that the BP/graphene hybrid not only improves the reversibility and hysteresis factors but also enhances the stability of the humidity sensor.

Black P/graphene hybrid: A fast response humidity sensor with good reversibility and stability.

Acetaldehyde removal tests were performed to compare the catalytic activity of the Kraft lignin char (KC), KOH-treated Kraft lignin char (KKC), and activated carbon (AC) along with their impregnation with Mn in a plasma reactor. The gasification characteristics (syngas content, and H/CO ratio) of yellow poplar were investigated using nickel catalysts supported on KC, KKC, AC, and γ-AlO in a U-type quartz reactor. KKC and Mn/KKC improved significantly the surface area and contents of O and N functional groups over the raw char. In particular, Mn/KKC showed the highest acetaldehyde-removal efficiency. The catalytic activity of Ni-impregnated KC, KKC, AC, and γ-AlO decreased in the order of Ni/KKC > Ni/AC > Ni/KC > Ni/γ-AlO for the gas yield and Ni/γ-AlO >Ni/KC > Ni/AC >Ni/KKC for the oil yield, respectively. The Ni/KKC provides a more conducive environment for gasification, resulting in larger amounts of syngas (H and CO) in the product gases. Moreover, Ni impregnated with char may be the most inexpensive and effective solution for achieving maximum tar reduction and syngas generation.

Acetaldehyde removal and increased H/CO gas yield from biomass gasification over metal-loaded Kraft lignin char catalyst.

Particulate matter (PM) from cooking is considered one of the most harmful indoor air pollutants causing numerous adverse health effects, and it is essential to comprehend the characteristics of the particles generated from cooking to prevent these problems. In this study, we investigated PM from the pan-frying of salmon using number concentration and developed emission rates as a function of time for ultrafine particles (UFPs < 100 nm) and accumulation mode particles (AMPs 0.1-1 μm). The newly defined emission rates vary significantly with time and are very different from the conventionally determined rates that do not consider the variation of particle concentration with time. The emission rate of UFPs decreased over time after a sharp rise, whereas that of AMPs continued to increase, resulting in a change in the proportions of UFPs and AMPs in the total PM from 93 to 7% to 72 and 28%, respectively. Particle-particle interactions such as coagulation and coalescence were observed between primary particles via high resolution transmission electron microscopy (HR-TEM), which is a plausible reason for the decreasing emission rate of UFPs with time. The emission rate as a function of time can serve as a tool to estimate PM from cooking, as well as to monitor the change trends through phenomena such as agglomeration.

Ki-Joon Jeon

Department of Environmental Engineering

Inha University

Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles

Ki-Joon Jeon

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Environmental Engineering

Inha University

Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles

Department of Environmental Engineering