Air Phthalate Emitted from Flooring Building Material by the Micro-Chamber Method: Two-Stage Emission Evaluation and Comparison

The phthalate and semi-volatile organic compounds (SVOCs) are modern chemical substances and extensively existing in the indoor environment. The European Commission stipulated the “European Unified Test Criteria”, since 2011, for the declared specifications of building products (CEN/TS 16516), based on the “lowest concentrations of interest (LCI)”, the index pollutants, test method, and emission standard of “phthalate” and “SVOC” were specified in detail. The purpose of this study is to use six common indoor floor construction products in Taiwan (regenerated pseudoplastic rubber flooring, healthy pseudoplastic imitation wood floor, regenerated pseudoplastic rubber flooring, PVC floor tile/floor, plastic click floor, composite floor covered with carpet) to detect the changes in the concentration of phthalate emitted to the air. The ISO 16000-25 Indoor air—Part 25: Determination of the emission of semi-volatile organic compounds by building products—micro-chamber method is used to build a DS-BMEMC (glass micro-chamber: volume 630 mL), the SVOC, including phthalate, is collected in two stages, in the stable conditions of temperature 25 °C, relative humidity 50% and air change rate 2 times/h, the Stage 1 emission detection experiment (24 h) is performed, and then the Stage 2 heating-up desorption emission detection experiment (40 min air sampling) is performed, the temperature rises to 200–220 °C, the phthalate and SVOC adsorbed on the glass micro-chamber is desorbed at a high temperature to catch the air substances, the air is caught by Tenax®—TA and Florisil® adsorption tube, and then the GC/MS and LC/MSMS analysis methods are used for qualitative and emission concentration analyses of SVOC of two-stage emission, respectively. The findings show that the floor construction materials emit nine phthalate SVOCs: DEHP, DINP, DNOP, DIDP, BBP, DBP, DIBP, DEP, and DMP, the two-stage emission concentrations are different, Stage 1 (normal temperature) emission concentration of six floor construction materials is 0.01–1.2% of Stage 2 (high temperature) emission concentration, meaning the phthalate SVOC of floor construction materials is unlikely to be volatilized or emitted at normal temperature. An interesting finding is that only S3 was detected DINP 72.6 (μg/m3) in stage 1. Others were detected DINP in stage 2. This might be because S3 has carpet on the surface. This implies that floor material with carpet may have an emission of DINP at normal temperature. The result of this study refers to the limited value evaluation of EU structural material standard emission TSVOC ≤ 0.1 ug/m3, the floor building material emissions are much higher than the evaluation criteria, increasing the health risk of users. The detection method and baseline can be used as the standard for controlling the emission of phthalate SVOC of Taiwan’s green building material labeling system in the future.

A new way to test the WIMP dark matter models

In this paper, we investigate the possibility of testing the weakly interacting massive particle (WIMP) dark matter (DM) models by applying the simplest phenomenological model which introduces an interaction term between dark energy (DE) and WIMP DM, i.e., Q = 3γDMHρDM. In general, the coupling strength γDE is close to 0 as the interaction between DE and WIMP DM is very weak, thus the effect of γDE on the evolution of Y associated with DM energy density can be safely neglected. Meanwhile, our numerical calculation also indicates that xf ≈ 20 is associated with DM freeze-out temperature, which is the same as the vanishing interaction scenario. As for DM relic density, it will be magnified by $$ \frac{2-3{\upgamma}_{\mathrm{DM}}}{2}{\left[2\pi {g}_{\ast }{m}_{\mathrm{DM}}^3/\left(45{s}_0{x}_f^3\right)\right]}^{\gamma_{\mathrm{DM}}} $$ 2 − 3 γ DM 2 2 π g ∗ m DM 3 / 45 s 0 x f 3 γ DM times, which provides a new way to test WIMP DM models. As an example, we analyze the case in which WIMP DM is a scalar DM. (SGL+SNe+Hz) and (CMB+BAO+SNe) cosmological observations will give γDM = $$ {0.134}_{-0.069}^{+0.17} $$ 0.134 − 0.069 + 0.17 and γDM = −0.0008 ± 0.0016, respectively. After further considering the constraints from DM direct detection experiment, DM indirect detection experiment, and DM relic density, we find that the allowed parameter space of the scalar DM model will be completely excluded for the former cosmological observations, while it will increase for the latter ones. Those two cosmological observations lead to an almost paradoxical conclusion. Therefore, one could expect more stringent constraints on the WMIP DM models, with the accumulation of more accurate cosmological observations in the near future.

Low limit of detection of the AlGaN/GaN-based sensor by the Kelvin connection detection technique

The AlGaN/GaN-based sensor is a promising POCT (point-of-care-testing) device featuring miniaturization, low cost, and high sensitivity. BNP is an effective protein biomarker for the early diagnosis of HF (heart failure). In this work, a novel AlGaN/GaN device with the Kelvin connection structure and the corresponding detection technique was proposed. This technique can effectively suppress the background noise and improve the SNR (signal-to-noise ratio). A BNP detection experiment was carried out to verify the effectiveness of this technique. It is shown that compared with that of the traditional detection method, the LOD (limit of detection) was improved from 0.47 ng/mL to 1.29 pg/mL. The BNP detection experiment was also carried out with a traditional electrochemical Au-electrode sensor with the same surface functionalization steps. The AlGaN/GaN sensor showed a better LOD than the Au-electrode sensor. Moreover, the influence of AlGaN/GaN sensor package on background noise was investigated with the mechanism of the noise source revealed. Finally, based on the optimized package, the optimal SNR quiescent operating point of the AlGaN/GaN sensor was determined. By biasing the sensor at the optimal quiescent operating point and immobilizing the magnetic beads with anti-BNP on the gate of the AlGaN/GaN sensor, the LOD for BNP detection was further improved to 0.097 pg/mL.

Gap Traversing Motion via a Hexapod Tracked Mobile Robot Based on Gap Width Detection

The authors developed a hexapod tracked mobile robot: a tracked mobile robot which is equipped with six legs attached to the robot’s body. In a transportation task, this robot can traverse a wide gap by supporting track driving with four front and rear legs while holding the target object with its two middle legs. To realize autonomous actions with this robot, we developed a two-dimensional distance measurement system using an infrared sensor. This system is very simple, with the sensor attached to a servomotor, such that it does not require high computing power for measurement. In addition, the system can be equipped at a lower cost than laser range finders and depth cameras. This paper describes the selection of the gap traversing mode according to gap width detected by the system. In this study, we conducted a gap width detection experiment and an autonomous gap traversing experiment using the hexapod tracked mobile robot with the proposed system. The obtained results confirm the effectiveness of the proposed system and autonomous traversing, which corresponds with the gap width detection.

Identifying molecules as biosignatures with assembly theory and mass spectrometry

The search for alien life is hard because we do not know what signatures are unique to life. We show why complex molecules found in high abundance are universal biosignatures and demonstrate the first intrinsic experimentally tractable measure of molecular complexity, called the molecular assembly index (MA). To do this we calculate the complexity of several million molecules and validate that their complexity can be experimentally determined by mass spectrometry. This approach allows us to identify molecular biosignatures from a set of diverse samples from around the world, outer space, and the laboratory, demonstrating it is possible to build a life detection experiment based on MA that could be deployed to extraterrestrial locations, and used as a complexity scale to quantify constraints needed to direct prebiotically plausible processes in the laboratory. Such an approach is vital for finding life elsewhere in the universe or creating de-novo life in the lab.

Implications of the XENON1T excess on the dark matter interpretation

The dark matter interpretation for a recent observation of excessive electron recoil events at the XENON1T detector seems challenging because its velocity is not large enough to give rise to recoiling electrons of $$ \mathcal{O}\left(\mathrm{keV}\right) $$ O keV . Fast-moving or boosted dark matter scenarios are receiving attention as a remedy for this issue, rendering the dark matter interpretation a possibility to explain the anomaly. We investigate various scenarios where such dark matter of spin 0 and 1/2 interacts with electrons via an exchange of vector, axial-vector, pseudo-scalar, or scalar mediators. We find parameter values not only to reproduce the excess but to be consistent with existing bounds. Our study suggests that the scales of mass and coupling parameters preferred by the excess can be mostly affected by the type of mediator, and that significantly boosted dark matter can explain the excess depending on the mediator type and its mass choice. The method proposed in this work is general, and hence readily applicable to the interpretation of observed data in the dark matter direct detection experiment.