Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds composed of multiple aromatic rings. PAHs are ubiquitous atmospheric pollutants which are well-recognized as carcinogenic, ...teratogenic and genotoxic compounds. PAHs are released from incomplete combustion or pyrolysis of materials containing carbon and hydrogen, such as coal, oil, wood and petroleum products. Understanding the characteristics of PAHs in atmosphere, source profiles and technologies available for controlling PAHs emission is essential to reduce the impacts of PAHs. This paper offers an overview on concentration and distribution of atmospheric PAHs, emission factors and distribution of PAHs in different sources, and available control technologies. Characteristics of atmospheric PAHs vary with meteorological conditions and emission sources, while characteristics of PAHs emission depend on burned material and combustion condition. Combination of some technologies may be necessary for effective removal of both low-ring and high-ring PAHs.
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•Characteristics of ambient PAHs depend on source and meteorological conditions.•Characteristics of PAHs emission vary with burned material and combustion condition.•Synergistic effects of PAHs and fine particles on human health should be addressed.•Studies on removal technologies and operating parameters should be strengthened.
The human body contains identity information that can be used for the person recognition (verification/recognition) problem. In this paper, we propose a person recognition method using the ...information extracted from body images. Our research is novel in the following three ways compared to previous studies. First, we use the images of human body for recognizing individuals. To overcome the limitations of previous studies on body-based person recognition that use only visible light images for recognition, we use human body images captured by two different kinds of camera, including a visible light camera and a thermal camera. The use of two different kinds of body image helps us to reduce the effects of noise, background, and variation in the appearance of a human body. Second, we apply a state-of-the art method, called convolutional neural network (CNN) among various available methods, for image features extraction in order to overcome the limitations of traditional hand-designed image feature extraction methods. Finally, with the extracted image features from body images, the recognition task is performed by measuring the distance between the input and enrolled samples. The experimental results show that the proposed method is efficient for enhancing recognition accuracy compared to systems that use only visible light or thermal images of the human body.
This study examines the impact of corporate governance on risk-taking in Vietnamese banks. Using data from 2007 to 2020 and employing the two-step generalized method of moments (GMM) technique, the ...study finds that certain aspects of corporate governance significantly influence bank stability efficiency. Specifically, the presence of female board members, independent directors, and larger board sizes are associated with improved stability efficiency, while the presence of foreign board members has a negative impact. These findings are consistent with agency theory, stewardship theory, and resource dependence theory. By employing the stochastic frontier approach, this research contributes to understanding how corporate governance characteristics can help mitigate risk-taking in emerging market contexts.
The nanocomposite of graphene oxide and silver nanoparticles has attracted great interest from scientists. In this work, silver@graphene oxide (Ag@GO) nanocomposite was synthesized
via
a biological ...reduction route using
Andrographis paniculata
extract as the reducing agent. The factors affecting the material preparation, comprising AgNO
3
volume, temperature, reaction time, and the amount of GO used, were investigated to select the appropriate conditions. As a result, silver nanoparticles were indicated to successfully form spherical-shaped particles with an average size of 31.93 ± 3.42 nm at 0.8 mL of the AgNO
3
, pH 10, and 90 °C for 30 min of the reaction time with a ratio of AgNO
3
: GO = 1 : 1, corresponding to the Ag@GO-1.6 sample. Moreover, Ag@GO-1.6 showed high antibacterial activity against both Gram-negative and Gram-positive bacteria. The composite also induced notable cytotoxicity against the cancerous KB cells while barely affecting the normal HEK-293 ones. Besides, Ag@GO-1.6 showed great sensing ability for H
2
O
2
with a relatively low limit of detection (2.65 μL) along with a wide detection range of 0-15 μM. Therefore, those results confirmed the potential applications of bio-synthesized Ag@GO in the medical and environmental fields.
The nanocomposite of graphene oxide and silver nanoparticles with uniform particle distribution was successfully green synthesized for bioactive assessment and hydrogen peroxoide electro-sensing application.
The greatest challenges towards the worldwide success of battery-powered electric vehicles revolve around the safety and energy density of the battery. Single-ion conducting polymer electrolytes ...address both challenges by replacing the flammable and unstable liquid electrolytes and enabling dendrite-free cycling of high-energy lithium metal anodes. To date, however, their commercial use has been hindered by insufficient ionic conductivities at ambient temperature (commonly not exceeding 10 −6 S cm −1 ) and the limited electrochemical stability towards oxidation, in particular when incorporating ether-type building blocks, limiting their application to rather low-voltage cathode materials like LiFePO 4 . Here, we introduce ether-free, nanostructured multi-block copolymers as single-ion conducting electrolytes, providing high thermal stability and self-extinguishing properties and, if plasticized with ethylene carbonate, ionic conductivities exceeding 10 −3 S cm −1 above 30 °C, i.e. , approaching that of state-of-the-art liquid electrolytes. Moreover, these single-ion conducting ionomers present highly reversible lithium cycling for more than 1000 h and, as a result of their excellent electrochemical stability, highly stable cycling of LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathodes. To the best of our knowledge, this is the first polymer electrolyte that presents such remarkable ionic conductivity and outstanding electrochemical stability towards both reduction and oxidation, thus, paving the way for advanced high-energy lithium metal batteries. Remarkably, the realization of well-defined continuous ionic domains appears to be the key to efficient charge transport through the electrolyte bulk and across the electrode/electrolyte interface, highlighting the importance of the self-assembling nanostructure. The latter is achieved by carefully (i) designing the copolymer structure, i.e. , introducing alternating ionic blocks with a very regular distribution of weakly coordinating anions along the polymer chain and rigid blocks, which are completely immiscible with ethylene carbonate, and (ii) choosing the processing solvent, taking into account its interaction with the different copolymer blocks.
Hospital effluents represent an important source for the release of antibiotics and antibiotic resistant bacteria into the environment. This study aims to determine concentrations of various ...antibiotics in wastewater before and after wastewater treatment in a rural hospital (60 km from the center of Hanoi) and in an urban hospital (in the center of Hanoi) in Vietnam, and it aims to explore the relationship between antibiotic concentrations in wastewater before wastewater treatment and quantities of antibiotics used in the rural hospital, over a period of one year in 2013. Water samples were collected using continuous sampling for 24 h in the last week of every month. The data on quantities of antibiotics delivered to all inpatient wards were collected from the Pharmacy department in the rural hospital. Solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry were used for chemical analysis. Significant concentrations of antibiotics were present in the wastewater both before and after wastewater treatment of both the rural and the urban hospital. Ciprofloxacin was detected at the highest concentrations in the rural hospital's wastewater (before treatment: mean = 42.8 µg/L; after treatment: mean = 21.5 µg/L). Metronidazole was detected at the highest concentrations in the urban hospital's wastewater (before treatment: mean = 36.5 µg/L; after treatment: mean = 14.8 µg/L). A significant correlation between antibiotic concentrations in wastewater before treatment and quantities of antibiotics used in the rural hospital was found for ciprofloxacin (r = 0.78; p = 0.01) and metronidazole (r = 0.99; p < 0.001).
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•An electrically conductive composite ink compounded of Ti3C2Tx, CNTs, and WPU.•EMI shielding films and sheet heaters were blade-printed by the composite ink.•The EMI shielding film ...exhibited a high EMI SE of 70 dB with a thickness of 200 µm.•The sheet heater showed an excellent Joule heating performance.
Wearable and flexible electronic devices have attracted much attention in recent decades due to their novel functionalities which can be applied in diverse fields such as identification of emergency, health monitoring, safety, and protection. For these devices to work precisely, they need a protective layer to prevent electromagnetic interference (EMI) and harsh environment. Therefore, developing multifunctional materials that can shield EMI and have thermal management functions has become essential. Herein, we propose a multifunctional conductive composite ink that can be applied to fabricate EMI shielding and sheet heater applications. The composite ink, which is eco-friendly, is a mixture of carbon nanotubes (CNTs) and heat-treated Ti3C2Tx MXene in waterborne polyurethane (WPU) matrix. Using the doctor blade printing method, we fabricated composite films with large size, high electrical conductivity, and good mechanical flexibility. The composite films with a thickness from 20 to 200 µm provided a remarkable EMI shielding performance from 20 dB to 70 dB in overall X-band and Ka-band. The excellent Joule heating performance and heat dissipation of the composite films were also demonstrated through practical sheet heaters and thermal interface materials (TIM). We believe that our composite ink could be a practical approach to delivering superior EMI shielding and thermal management performance in printed wearable electronics applications.
Notch signaling plays an important role in development and cell fate determination, and it is deregulated in human hematologic malignancies and solid tumors. This review includes a brief introduction ...of the relevant pathophysiology of Notch signaling pathway and primarily focuses on the clinical development of promising agents that either obstruct Notch receptor cleavages such as γ-secretase inhibitors (GSIs) or interfere with the Notch ligand-receptor interaction by monoclonal antibodies (mAbs). Antitumor activity by GSIs and mAbs administered as single agent in early phases of clinical trials has been observed in advanced or metastatic thyroid cancer, non-small cell lung cancer, intracranial tumors, sarcoma or desmoid tumors, colorectal cancer with neuroendocrine features, melanoma and ovarian cancer. A number of mechanism-based adverse events particularly gastrointestinal toxicities emerged and mitigation strategies are developed after testing multiple GSIs and Notch targeting mAbs. We also discuss pharmacodynamic biomarkers in conjunction with methods of assessment of the molecular target inhibition validation. Biomarkers of efficacy or benefit may be of importance for a successful development of this class of drugs.
•A rigorous SMR model with a multiscale reactor, wall and furnace was developed.•The temperature, pressure, heat flux and mole fraction agree well with a reference.•A combined method using an SMR ...dynamic model and ANN was suggested for industries.•The developed approach predicts the output with 98.91% accuracy in a few seconds.•The method can be used for the design and online optimization of H2 production.
The steam methane reformer (SMR) has become more attractive owing to the increasing importance of hydrogen production using natural gas. This study developed a rigorous dynamic model for an SMR including sub-models for a multiscale reactor, wall, and furnace. The developed SMR model was validated within a small error (lower than 4%) using the reference data such as temperature, pressure, mole fraction, and average heat flux. The results predicted by changing the catalyst parameters and operation conditions confirmed the reliability of the model. Therefore, the developed model was used to generate the SMR performance data using a deterministic and stochastic simulation with four main operating variables: the inlet flow rate, temperature, S/C ratio of the reactor side, and the inlet flow rate of the furnace side. To reduce the data dimensionality, the resultant dataset was analyzed using the principle components based on a singular value decomposition method. Artificial neural network (ANN) trained through 81 datasets was applied for the feed-forward back propagation of a neural network to map the relationship between the operating variables and predicted outputs. And the ANN relation predicted the outputs (temperature, velocity, pressure, and mole fraction of components) with higher than 98.91% accuracy. Furthermore, the computational time was significantly reduced from 1200 s (dynamic simulation) to 2 s (ANN). The developed methodology can be applied not only for the online operation and optimization of a reformer with high accuracy but also for the design of a hydrogen production system at low computational cost.
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