VOC

Emissions from the transportation sector are rapidly changing worldwide; however, the interplay of such emission changes in the face of climate change are not as well understood. This two-part study examines the impact of projected emissions from the U.S. transportation sector (Part I) on ambient air quality in the face of climate change (Part II). In Part I of this study, we describe the methodology and results of a novel Technology Driver Model (see graphical abstract) that includes 1) transportation emission projections (including on-road vehicles, non-road engines, aircraft, rail, and ship) derived from a dynamic technology model that accounts for various technology and policy options under an IPCC emission scenario, and 2) the configuration/evaluation of a dynamically downscaled Weather Research and Forecasting/Community Multiscale Air Quality modeling system...

Honeydew is considered a cornerstone of the interactions between aphids and their natural enemies. Bacteria activity occurring in aphid honeydew typically results in the release of volatile organic compounds (VOCs) that are used by the natural enemies of aphids to locate their prey. Because atmospheric carbon dioxide (CO₂) concentration directly impacts the physiology of plants, we raise the hypothesis that elevated CO₂ concentrations impact the quantity of honeydew produced by aphids, as well as the diversity and quantity of honeydew VOCs, leading to cascade effects on the foraging behavior of aphids' natural enemies...

To synergize both steric and electronic factors in designing the dyes for dye-sensitized solar cells (DSSCs), a series of cis-configured unsymmetrical squaraine dyes P11-15 with suitably functionalized alkyl groups and electron withdrawing group containing squaric acid unit were synthesized, respectively. These dyes capture the importance of (i) the effect and position of branched alkyl groups, (ii) mono- and di-anchoring groups containing dyes and (iii) further appending alkyl groups through the cyanoester vinyl unit on the central squaric acid units of D-A-D based cis-configured squaraine dyes...

Most plant-based emissions of volatile organic compounds (VOCs) are considered mainly temperature dependent. However, certain oxygenated VOCs (OVOCs) have high water solubility; thus, also stomatal conductance could regulate their emissions from shoots. Due to their water solubility and sources in stem and roots, it has also been suggested that their emissions could be affected by transport in xylem sap. Yet, further understanding on the role of transport has been lacking until present. We used shoot-scale long-term dynamic flux data from Scots pines (Pinus sylvestris) to analyse the effects of transpiration and transport in xylem sap flow on emissions of three water soluble OVOC: methanol, acetone and acetaldehyde...

Notwithstanding its mitosporic nature, an improbable morpho-transformation state i. e., sclerotial development (SD), is vaguely known in Aspergillus oryzae . Nevertheless an intriguing phenomenon governing mold's development and stress response, the effects of exogenous factors engendering SD, especially the volatile organic compounds (VOCs) mediated interactions (VMI) pervasive in microbial niches have largely remained unexplored. Herein, we examined the effects of intra-species VMI on SD in A. oryzae RIB 40, followed by comprehensive analyses of associated growth rates, pH alterations, biochemical phenotypes, and exometabolomes...

Minimizing the strain induced undesirable effects is one of the major efforts to be made for flexible electronics. This work reports a highly sensitive flexible gas sensor with ultra-low strain response, which is potentially suitable for wearable electronics applications. The gas sensing material is a free-standing and flexible thin film made of graphene/ethyl cellulose (EC) nanocomposite, which is then integrated with flexible substrate of polyethylene terephthalate. The sensor exhibits relative resistance change within 0...

In this study, interactions between the superalkali species Li3F2 and four volatile organic compounds (VOCs), methanol, ethanol, formaldehyde, and acetaldehyde, are assessed using the CBS-QB3 composite model. Adiabatic ionization energy (AIE), adiabatic electron affinity (AEA), binding energy (BE), charge transfer (∆q), and highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO-LUMO) gaps have been computed. Stronger interactions are observed between Li3F2 and the aldehydes than alcohols...

All inorganic double metal perovskite materials have recently drawn much attention due to their three dimensionality (3D) and non-toxic nature to replace lead based perovskite material. Among all those double perovskite materials, theoretical works have demonstrated that Cs2AgBiBr6 shows high stability and possesses suitable bandgap for solar cell application. However, the film-forming ability of Cs2AgBiBr6 is found to be the utmost challenge hindering its development in thin film solar cell device. In this work, high quality Cs2AgBiBr6 film with ultra-smooth morphology, micro-sized grains, and high crystallinity is realized via anti-solvent dropping technology and post-annealing process under high temperature...

Gasoline vehicles are a major source of anthropogenic secondary organic aerosols (SOAs). However, current models based on known precursors fail to explain the substantial SOAs from vehicle emissions due to the inadequate understanding of the formation mechanism. To provide more information on this issue, the formation of SOAs from ozonolysis of four light-duty gasoline vehicle exhaust systems was investigated with a vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS). Remarkable SOAs formation was observed and the SOAs were primarily aliphatic alkenes...

Biogenic volatile organic compounds (BVOCs) are released to the atmosphere from vegetation. BVOCs aid in maintaining ecosystem sustainability via a series of functions, however, VOCs can alter tropospheric photochemistry and negatively affect biological organisms at high concentrations. Due to their critical role in ecosystem and environmental sustainability, BVOCs receive particular attention by global change biologists. To understand how plant VOC emissions affect stress responses within a dose-response context, dose responses should be evaluated...

Alkyl nitrates (RONO2) are important reservoirs of atmospheric nitrogen, regulating nitrogen cycling and ozone (O3) formation. In this study, we found that propane and n-butane were significantly lower at the offshore site (WSI) in Hong Kong (p<0.05), whereas C3-C4 RONO2 were comparable to the suburban site (TC) (p>0.05). Stronger oxidative capacity at WSI led to more efficient RONO2 formation. Relative incremental reactivity (RIR) was for the first time used to evaluate RONO2-precursors relationships...

Bacterially produced volatile organic compounds (VOCs) can modify growth patterns of eukaryotic hosts and competing/cohabiting microbes. These compounds have been implicated in skin disorders and attraction of biting pests. Current methods to detect and characterize VOCs from microbial cultures can be laborious and low-throughput, making it difficult to understand the behavior of microbial populations. In this work we present an efficient method employing gas chromatography/mass spectrometry with autosampling to characterize VOC profiles from solid-phase bacterial cultures...

A microwave-heated adsorbent-reactor system has been used for the continuous cleaning of air streams containing n-hexane at low concentrations. Both a single catalytic bed (PtY zeolite) and a double (adsorptive DAY zeolite + catalytic PtY zeolite) fixed-bed reactor configurations were studied. The zeolites were selectively heated by short periodic microwave pulses that caused the desorption of n-hexane and its subsequent catalytic combustion. The double bed configuration was attractive because it allowed nearly the same performance with only half of the catalyst load...

We report three n-type polymeric electron acceptors (PFPDI-TT, PFPDI-T and PFPDI-Se) based on the fused perylene diimide (FPDI) and thieno[3,2-b]thiophene, thiophene or selenophene units for all-polymer solar cells (all-PSCs). These FPDI-based polymer acceptors exhibit the strong absorption between 350 nm and 650 nm with the wide optical badgaps of 1.86~1.91 eV, showing good absorption compensation with the narrow bangap polymer donor. The lowest unoccupied molecular orbital (LUMO) energy levels were located at around -4...

This proceedings report presents the outcomes from an international Expert Meeting to establish a consensus on the recommended technical and operational requirements for air quality within modern assisted reproduction technology (ART) laboratories. Topics considered included design and construction of the facility, as well as its heating, ventilation and air conditioning system; control of particulates, micro-organisms (bacteria, fungi and viruses) and volatile organic compounds (VOCs) within critical areas; safe cleaning practices; operational practices to optimize air quality while minimizing physicochemical risks to gametes and embryos (temperature control versus air flow); and appropriate infection-control practices that minimize exposure to VOC...

This work investigated the effect of Zn excess on growth, metal accumulation and photosynthetic changes in Tetradenia riparia, in relation to possible variations in the composition of the plant volatilome. Experiments were carried out in hydroponics exposing plants to a range of Zn concentrations. Zinc excess negatively affected plant growth in a dose-dependent manner. The metal was accumulated proportionally to its concentration in the medium and preferentially allocated to roots. All the photosynthetic parameters and the concentration of some photosynthetic pigments were negatively affected by Zn, whereas the level of leaf total soluble sugars remained unchanged...

Explicit structural inference is one key point to improve the accuracy of scene parsing. Meanwhile, adversarial training method is able to reinforce spatial contiguity in output segmentations. To take both advantages of the structural learning and adversarial training simultaneously, we propose a novel deep learning network architecture called Structural Inference Embedded Adversarial Networks (SIEANs) for pixel-wise scene labeling. The generator of our SIEANs, a novel designed scene parsing network, makes full use of convolutional neural networks and long short-term memory networks to learn the global contextual information of objects in four different directions from RGB-(D) images, which is able to describe the (three-dimensional) spatial distributions of objects in a more comprehensive and accurate way...

The analysis of volatile organic compounds (VOCs) allows non-invasive investigations of diseases. Animal studies are conducted as a model to perform research of VOCs and their relation to diseases. In large animal models ruminants were often used as experimental animal. The effect of their physiological eructation on VOC exhalation has not been examined yet and is the objective of this study.&#13; Methods: Continuous breath profiles of 2 young cattle, 4 adult goats and 4 adult sheep were measured through a mask, covering mouth and nose, in real-time (200 ms) by means of PTR-TOF-MS...

We present the fabrication, characterization, and testing of an electrochemical Volatile Organic Compound (VOC) sensor operating in gaseous condition at room temperature. It is designed to be microfabricated to prove the sensing principle based on Cyclic Voltammetry (CVs). It is composed of a Working Electrode (WE), a Counter Electrode (CE), a Reference Electrode (RE) and a Nafion solid-state electrolyte. Nafion is a polymer that conducts protons (H+ ) generated from redox reactions from the WE to the CE. The sensor needs to be activated prior to exposure to gases, which consists of hydrating the Nafion layer to enable its ion conduction properties...

Light-duty gasoline vehicles have drawn public attention in China due to their significant primary emissions of particulate matter and volatile organic compounds (VOCs). However, little information on secondary aerosol formation from exhaust for Chinese vehicles and fuel conditions is available. In this study, chamber experiments were conducted to quantify the potential of secondary aerosol formation from the exhaust of a port fuel injection gasoline engine. The engine and fuel used are common in the Chinese market, and the fuel satisfies the China V gasoline fuel standard...