Nano Carbon Black-Based High Performance Wearable Pressure Sensors.

The reasonable design pattern of flexible pressure sensors with excellent performance and prominent features including high sensitivity and a relatively wide workable linear range has attracted significant attention owing to their potential application in the advanced wearable electronics and artificial intelligence fields. Herein, nano carbon black from kerosene soot, an atmospheric pollutant generated during the insufficient burning of hydrocarbon fuels, was utilized as the conductive material with a bottom interdigitated textile electrode screen printed using silver paste to construct a piezoresistive pressure sensor with prominent performance. Owing to the distinct loose porous structure, the lumpy surface roughness of the fabric electrodes, and the softness of polydimethylsiloxane, the piezoresistive pressure sensor exhibited superior detection performance, including high sensitivity (31.63 kPa-1 within the range of 0-2 kPa), a relatively large feasible range (0-15 kPa), a low detection limit (2.26 pa), and a rapid response time (15 ms). Thus, these sensors act as outstanding candidates for detecting the human physiological signal and large-scale limb movement, showing their broad range of application prospects in the advanced wearable electronics field.

Glyphosate and nutrients removal from simulated agricultural runoff in a pilot pyrrhotite constructed wetland.

Pyrrhotite is often considered as a gangue mineral, and discarded in mine wastes and tailings. Glyphosate and fertilizer, often excessively used in agriculture, flow into water bodies with agriculture runoff, and cause pollution of water bodies. In this study, the pyrrhotite was used as a substrate in a pilot constructed wetland (CW) to remove the glyphosate and nutrients from simulated agriculture runoff. In nearly one year, the pilot pyrrhotite constructed wetland (Pyrr-CW) removed 90.3 ±â€¯6.1% of glyphosate, 88.2 ±â€¯5.1 of total phosphorus (TP) and 60.40 ±â€¯5.60% of total nitrogen (TN) on average, much higher than the control CW. The abundances of sulfur-oxidizing bacteria, such as Sulfurifustis, Sulfuriferula and Thiobacillus, were much higher in the Pyrr-CW than those in the control CW. In the Pyrr-CW goethite was produced by pyrrhotite aerobic oxidation (PAO) and pyrrhotite autotrophic denitrification (PAD) continuously and spontaneously. Higher glyphosate and TP removals were resulted from adsorption on the goethite produced, and higher TN removal was attributed to the PAD. High glyphosate and nutrients removal could keep a long term until the pyrrhotite in the Pyrr-CW was used up. The phosphorus (P) sequestered in the Pyrr-CW existed mainly in organic P, (Fe + Al)P and (Ca + Mg)P, and their order was (Fe + Al)P > organic P > (Ca + Mg)P. No heavy metal ions released from the Pyrr-CW. With higher and lasting removal rate, and lower cost, the Pyrr-CW is a promising technology for simultaneous glyphosate and nutrients removal from agricultural runoff and wastewater.

Natural pyrite to enhance simultaneous long-term nitrogen and phosphorus removal in constructed wetland: Three years of pilot study.

The searches for suitable substrates with high capacity for phosphorus (P) removal and promoting denitrification for enhancing nitrogen (N) removal have been a key work in constructed wetlands (CWs) research in the past several decades. But few substrates enhancing simultaneous long-term N and P removal in CWs have been found before. In this study, two subsurface flow pilot-scale wetlands using natural pyrite and limestone as substrates were constructed. After 3 year of operation, we found that pyrite had no negative effects on growth of reeds, removals of chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N), but enhanced long-term total nitrogen (TN) and total phosphorus (TP) removals in constructed wetland. In the three years, the average TP and TN removals of pyrite constructed wetland (PCW) were 87.7 ± 14.2% with 0.25 ± 0.20 mg/L of average effluent TP and 69.4 ± 21.4% with 4.0 ± 3.2 mg/L of average effluent TN, respectively. The main P form in the PCW was (Fe + Al)-bound P. The mechanisms of the PCW with enhanced simultaneous long-term N and P removals were anaerobic and aerobic oxidations of pyrite. The main bacteria were Anaeromyxobacter (4.9%), Ramlibacter (4.8%), Defluviicoccus (4.2%), Azoarcus (3.7%), Geobacter (3.4%), and they were highly related to anaerobic and aerobic oxidation of pyrite in the PCW.

Morphology and Mechanical Properties of Polyimide Films: The Effects of UV Irradiation on Microscale Surface.

As an attractive dielectric material, polyimide has been widely used in the field of electronics, aerospace, and automobiles due to its useful mechanical properties and good chemical resistance. UV irradiation was considered to be the main factor related to the damage and failure of polyimide. Here the effects of UV irradiation on the surface morphology and microscale mechanical properties of polyimide films are characterized by atomic force microscopy (AFM). The surface roughness of the UV-irradiated samples developed and the mechanical properties degraded with the radiation dose increased. For comparison, uniaxial tensile test was performed to obtain the macroscale Young's modulus of polyimide film. The UV-irradiated damaging depth was simulated with finite element method (FEM).

Strain engineering on transmission carriers of monolayer phosphorene.

The effects of uniaxial strain on the structure, band gap and transmission carriers of monolayer phosphorene were investigated by first-principles calculations. The strain induced semiconductor-metal as well as direct-indirect transitions were studied in monolayer phosphorene. The position of CBM which belonged to indirect gap shifts along the direction of the applied strain. We have concluded the change rules of the carrier effective mass when plane strains are applied. In band structure, the sudden decrease of band gap or the new formation of CBM (VBM) causes the unexpected change in carrier effective mass. The effects of zigzag and armchair strain on the effective electron mass in phosphorene are different. The strain along zigzag direction has effects on the electrons effective mass along both zigzag and armchair direction. By contrast, armchair-direction strain seems to affect only on the free electron mass along zigzag direction. For the holes, the effective masses along zigzag direction are largely affected by plane strains while the effective mass along armchair direction exhibits independence in strain processing. The carrier density of monolayer phosphorene at 300 K is calculated about [Formula: see text] cm-2, which is greatly influenced by the temperature and strain. Strain engineering is an efficient method to improve the carrier density in phosphorene.

A cost-benefit analysis of landfill mining and material recycling in China.

Landfill mining is an environmentally-friendly technology that combines the concepts of material recycling and sustainable waste management, and it has received a great deal of worldwide attention because of its significant environmental and economic potential in material recycling, energy recovery, land reclamation and pollution prevention. This work applied a cost-benefit analysis model for assessing the economic feasibility, which is important for promoting landfill mining. The model includes eight indicators of costs and nine indicators of benefits. Four landfill mining scenarios were designed and analyzed based on field data. The economic feasibility of landfill mining was then evaluated by the indicator of net present value (NPV). According to our case study of a typical old landfill mining project in China (Yingchun landfill), rental of excavation and hauling equipment, waste processing and material transportation were the top three costs of landfill mining, accounting for 88.2% of the total cost, and the average cost per unit of stored waste was 12.7USDton(-1). The top three benefits of landfill mining were electricity generation by incineration, land reclamation and recycling soil-like materials. The NPV analysis of the four different scenarios indicated that the Yingchun landfill mining project could obtain a net positive benefit varying from 1.92 million USD to 16.63 million USD. However, the NPV was sensitive to the mode of land reuse, the availability of energy recovery facilities and the possibility of obtaining financial support by avoiding post-closure care.

[Limestone and pyrite-limestone constructed wetlands for treating river water].

Polluted river water was treated with limestone and pyrite-limestone subsurface horizontal constructed wetlands. The aims were to know the performance of two wetlands on removal of common pollutants, especially nitrogen and phosphorus, and analyze the actions of these minerals. The relationship between hydraulic retention time and purification performance of two constructed wetlands was studied. The optimal hydraulic retention time for pollutant removal was about 3 d, The average removal efficiency of COD, TN and TP were 51%, 70% and 95%, respectively. With same influent and hydraulic loading, the average removal efficiency of COD, NH4+ -N, TN and TP were 53.93%, 82.13%, 66%, 50.9%, and 51.66%, 77.43%, 72.06%, 97.35% for limestone and pyrite-limestone constructed wetlands, respectively. There were few differences between limestone and pyrite-limestone wetlands on COD removal, but the nitrogen and phosphorus removal of pyrite-limestone constructed wetland was higher than that of limestone constructed wetland. The phosphorus removal of pyrite-limestone wetland was more efficiency and stable, not affected by temperature.

A serotonin-sensitive sensor for investigation of taste cell-to-cell communication.

Taste receptor cells are the taste sensation elements for sour, salty, sweet, bitter and umami sensations. It was demonstrated that there are cell-to-cell communications between type II (sour) and type III (sweet, bitter and umami) taste cells. Serotonin (5-HT) is released from type III cells, which is the only type of taste cells that has synaptic process with sensory afferent fibers. Then, taste information is transmitted via fibers to the brain. During this process, 5-HT plays important roles in taste information transmission. In order to explore a sensor to detect 5-HT released from taste cell or taste cell networks, we develop a 5-HT sensitive sensor based on LAPS chip. This sensor performs with a detection limit of 3.3 × 10(-13)M and a sensitivity of 19.1 mV per concentration decade. Upon the stimuli of sour and mix (bitter, sweet and umami) tastants, 5-HT released from taste cells could be detected flexibly, benefit from the addressability of LAPS chip. The experimental results show that the local concentration of 5-HT is around several nM, which is consistent with those from other methods. In addition, immunofluorescent imaging technique is utilized to confirm the functional existence of both type II and III cells in a cluster of isolated taste cells. Different types of taste cells are labeled with corresponding specific antibody. This 5-HT sensitive LAPS chip provides a potential and promising way to detect 5-HT and to investigate the taste coding and information communication mechanisms.