A green and facile protocol of thermal treatment of graphene oxide (GO) with urea was adopted to synthesize nitrogen-doped graphene (NG-Urea-air) at a low temperature (350 °C) in the static air. The ...resulting sample exhibited outstanding catalytic performance to activate peroxymonosulfate (PMS) toward organic degradation. The NG-Urea-air induced 49.7- and 11.5-fold enhancement over GO and pristine reduced graphene oxide (rGO-air). Moreover, the influences of nitrogen precursors including organic chemicals (urea, cyanamide, and melamine) and inorganic salts (ammonium nitrate and ammonium chloride) were investigated, and urea was demonstrated to be the best precursor for synthesizing N-doped graphene with a relative high doping level (18.7 at.%). The classical radical quenching and advanced in situ electron paramagnetic resonance (EPR) technology revealed that the outstanding oxidative effectiveness of PMS/NG-Urea-air system was originated from the nonradical oxidation pathway, in which PMS was activated by the positively charged carbon domains next to nitrogen atoms and the phenol was oxidized simultaneously on the carbon network via rapid charge transfer. Meanwhile, singlet oxygen and radicals may also partially contribute to the complete phenol degradation. This study facilitates a fundamental investigation of heteroatom doping progress during thermal treatment and sheds light on the insights into carbocatalysis in environmental remediation.
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•Ethylene was utilized in HTL of municipal sewage sludge for the first time.•The use of ethylene atmosphere improved the stability of HTL biocrude.•The reduction temperature of red ...mud influenced the catalytic activities.•RRM500 catalyst promoted ring-opening reaction in biocrude.•RRM500-ethylene combination reduced nitrogen content of HTL oil.
In this study, ethylene and nitrogen(inert) reaction environments were applied into the hydrothermal liquefaction (HTL) process of municipal sewage sludge with red mud catalyst to evaluate the effects on biocrude and other byproducts. Red mud in three oxidation states was used: red mud calcined at 575 °C (CRM), reduced at 500 °C (RRM500), and 700 °C (RRM700). The RRM500 lowered the acidity by 14%; whereas, the RRM700 minimized the viscosity by 47% comparing to non-catalytic-inert biocrude samples. The ethylene ambience successfully maximized the biocrude yield by 41.6 wt% without any catalyst. The viscosity of the biocrudes produced under ethylene environment showed lower differences compared to nitrogen environment. The RRM500-ethylene reaction efficiently reduced the nitrogen content in the biocrude by 14%. These results suggested that the ethylene atmosphere has the potential for improved biocrude production during catalytic HTL treatment.
Museum contents are vulnerable to bad ambience conditions and human vandalization. Preserving the contents of museums is a duty towards humanity. In this paper, we develop an Internet of Things ...(IoT)-based system for museum monitoring and control. The developed system does not only autonomously set the museum ambience to levels that preserve the health of the artifacts and provide alarms upon intended or unintended vandalization attempts, but also allows for remote ambience control through authorized Internet-enabled devices. A key differentiating aspect of the proposed system is the use of always-on and power-hungry sensors for comprehensive and precise museum monitoring, while being powered by harvesting the Radio Frequency (RF) energy freely available within the museum. This contrasts with technologies proposed in the literature, which use RF energy harvesting to power simple IoT sensing devices. We use rectenna arrays that collect RF energy and convert it to electric power to prolong the lifetime of the sensor nodes. Another important feature of the proposed system is the use of deep learning to find daily trends in the collected environment data. Accordingly, the museum ambience is further optimized, and the system becomes more resilient to faults in the sensed data.
The COVID-19 pandemic has had significant consequences for Americans' daily lives. Many people are spending more time in their homes due to work from home arrangements, stay at home orders, and ...closures of businesses and public gathering spaces. In this study, we explored how one's attachment to their home may help to buffer their mental health during this stressful time. Data were collected from a three-wave, longitudinal sampling (n=289) surveyed at baseline, two, and four weeks after. We found a clear relationship between an individual's attachment to home and positive mental health. Across all three waves, home attachment was negatively associated with symptoms of depression, anxiety, and stress. Furthermore, participants' home attachment at baseline was predictive of subsequent mental health two weeks after, which suggests that one's relationship to their home was particularly important during the initial onset of the national response to the outbreak. Predictors of home attachment included conscientiousness, agreeableness, and restorative ambience. Over the course of the study, kinship ambience also emerged as a predictor of home attachment. In the midst of increased mental health concerns and limited resources due to COVID-19, the home may buffer some individuals from depressive and anxiety-related symptoms by functioning as a source of refuge, security, and stability.
•Study tests relationship between home attachment and mental health during pandemic.•Home attachment negatively associated with stress, anxiety, and depressive symptoms.•Attachment during the initial adjustment to COVID-19 was particularly important.•Home ambience of kinship became a stronger predictor of home attachment over time.
Pd-based constituents have been widely used for sensing H2 due to the incredible selectivity, however, the sensitivity and measuring range in anaerobic ambience are largely limited for these using ...electronic signals. The variations between Pd and coincided hydride would typically increase resistance upon absorbing H2, whereas the intrinsic α-β phase transition alters the regularity of response features. Surprisingly, an inverse response has been detected by alloying Ag into Pd lattice, and this negative trend could be resulting from a new mechanism based on the experimental investigation and first-principles calculations. It is the contribution of modified Pd/Ag ratio, which optimizes the electronic band structure and density of states (DOS), thus a trade-off between free electron concentration and coincided scattering strength, would tune the response trend and make a switch. Consequently, the resistance of films with proper Ag contents, would be decreased at low H2 concentrations (10 ppm-4 vt.%), and the detection range can be widened as the trend reverses to be positive at high concentrations. These, combined with the ultralow detection limit of 10 ppm, and proportional sensor response values from − 0.5% of 10 ppm H2 to − 3.8% of 4 vt.% at 1 atm, confirm the promising virtues of anaerobic ambience used Pd-based sensors configuring inverse response. Furthermore, our study elucidates that alloying proper elements into Pd to modify the electronic band structure and DOS on Fermi energy, may be an effective strategy for promoting H2 sensing features.
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•Anaerobic ambience used H2 sensors with ultralow detection limit and proportional response are fabricated successfully.•The response trend switch is driven by the balance between free electron concentration and coincided scattering strength.•Baseline drifts of Ag alloyed sensors are suppressed to improve the signal-to-noise ratio.•Experimental investigation and calculations are cooperated to connect the response variation with band structure.
A large amount of cold energy can be recovered while in use because of the large temperature difference between the cryogenic fluid and the ambience. This study designed and built a thermoelectric ...power generation system for cold energy. Taking liquid nitrogen as the cryogenic liquid, the thermoelectric characteristics of the system were studied experimentally. In addition, the influence of the heat transfer process of the cryogenic fluid on the thermoelectric characteristics was determined. The results revealed that in the liquid-phase and two-phase regions, the temperature difference between the hot and cold end increased in the gasification process. However, in the gas-phase region, it first decreased and then increased. The temperature difference between the hot and cold module ends was small, being only 7.2–28.1 °C. The poor heat transfer capacity at the hot end of the generator restricted the improvement of the temperature difference at the hot and cold ends. Nevertheless, the flow rate change had a relatively small impact on the open-circuit voltage. Although the thermoelectric conversion efficiency remains low, it is expected that the efficiency can be significantly improved by developing high-efficiency low-temperature thermoelectric materials and by improving the heat exchange performance of the hot end of the generator.
The present paper explores descriptions of natural landscapes excerpted from two travel books, namely,
, by Paul Theroux, and
, by Robert D. Kaplan. The paper aims at analyzing how certain linguistic ...choices in a given stretch of text conspire to construe the ambience of descriptive passages of natural landscapes in travel writing. This will be carried out by combining insights from Conceptual Metaphor Theory (CMT) and Frame Semantics (FS). I will be focusing on the ambience of the natural depictions, that is, the sense of the natural world evoked in the reader’s mind by the language of the text. This will be dealt with by examining the lexical choices made by both authors, paying special attention to the adjectives. The excerpts under investigation have been selected since the descriptive language in them evokes frames and conceptual domains, which, in turn, yield a series of metaphors. These metaphors summarize the tone of the travel books, that is, the authorial texture and, especially, the ideological stance of the authors. Paul Theroux displays a more empathetic approach to the surrounding nature and its people, whereas Robert D. Kaplan adopts a more distant, analytical stance.
Phosphorene, monolayer or few‐layer black phosphorus (BP), has recently triggered strong scientific interest for lithium/sodium ion batteries (LIBs/SIBs) applications. However, there are still ...challenges regarding large‐scale fabrication, poor air stability. Herein, we report the high‐yield synthesis of phosphorene with good crystallinity and tunable size distributions via liquid‐phase exfoliation of bulk BP in formamide. Afterwards, a densely packed phosphorene–graphene composite (PG‐SPS, a packing density of 0.6 g cm−3) is prepared by a simple and easily up‐scalable spark plasma sintering (SPS) process. When working as anode materials of LIBs, PG‐SPS exhibit much improved first‐cycle Coloumbic efficiency (60.2%) compared to phosphorene (11.5%) and loosely stacked phosphorene–graphene composite (34.3%), high specific capacity (1306.7 mAh g−1) and volumetric capacity (256.4 mAh cm−3), good rate capabilities (e.g., 415.0 mAh g−1 at 10 A g−1) as well as outstanding long‐term cycling life (91.9% retention after 800 cycles at 10 A g−1). Importantly, excellent air stability of PG‐SPS over the 60 days observation in maintaining its high Li storage properties can be achieved. On the contrary, 95.2% of BP in PG sample was oxidized after only 10 days exposure to ambience, leading to severe degradation of electrochemical properties.
A densely packed phosphorene–graphene composite is prepared by a simple and easily upscalable spark plasma sintering process, which exhibits much improved 1st‐cycle Coulombic efficiency, high volumetric capacity, good rate capabilities as well as an outstanding cycling life, especially robust air stability in maintaining its high Li storage properties.
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•The molecular-gated unidirectional actuator is driven by temperature and humidity.•This actuator protects customers from environmental stress as well as early warning.•LBL ...self-assembly realizes functionalization and engineering of protective devices.•The credible tolerance of actuators depend on the outstanding self-healing capacity.
More attention has paid to health events caused by the epidemic and harmful interferences where personal protective equipment (PPE) become of vital importance. Traditional protection can only provide limited defenses. Thus, comprehensive PPE tailored with more practical performances and more facile routines gets highly desirable. However, functional integrations and engineering implementations of such PPE remain challenging. Herein, a dual ambiences-driven molecular gating-based unidirectional actuator for multi-mode personal protection is designed. To fabricate this Janus actuating film, poly(3,4-ethylenedioxythiophene) and poly(N-isopropyl acrylamide) were deposited as a thermal-sensitive side while alginate, 2-hydroxypropyltrimethyl ammonium chloride chitosan, polyvinyl alcohol and poly-dopamine nanoparticles were overlaid onto the other for humidity response via layer-by-layer self-assembling. As a result, pleasurable humidity/temperarure management (55%/33 ℃ against adverse conditions), respiratory detection (responsive signal to exhaled air), oil repellent for anti-bacterial-adhesion (antibacterial rate > 92.2%), transparent visual-monitoring hazardous compounds (opaque to transparency: 0 ∼ 85.3%), electromagnetic shielding (>15 dB), credible-tolerance of damage (self-healing efficiency > 91.7%) were integrated into a single actuator (PROTECT actuator). Our PROTECT actuator could protect customers from environmental stress as well as early warning. This strategy opens a new era of novel custom-tailorable and easy-to-obtain protection devices, especially noncontact-perception systems and all-round defensive setups.
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