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Background Humans can recognize the physical properties of objects by touching them, even when vision is unavailable. Tactile perception is important for humans in interacting with the environment. The triangular ridged textures are usually added to surface to improve the grip reliability of products, but the sharp edge of triangular ridge induces sharp and uncomfortable feeling. Materials and methods To study the effect of the edge shape of triangular ridged texture on brain activity, functional magnetic resonance imaging technique was used to obtain the blood oxygen level-dependent (BOLD) signal of subjects during the touching of textured surfaces. Samples with sharp, round, and flat shape ridged textures were chosen as the tactile stimulus. Results The contralateral postcentral gyrus, the precentral gyrus, the inferior parietal lobule, and the supramarginal gyrus, corresponding with the functional regions of the primary somatosensory cortex (SI), the secondary somatosensory cortex (SII), and the primary motor cortex (MI) were related to the perception of three shape ridged textures. The main brain activation located in the postcentral gyrus and the SI. The tactile information of three shape ridged textures was received by Brodmann area (BA) 3 of the SI, and then inputted to BA 2 of the SI, the further tactile discrimination of shape of ridged textures was involved in BA40 of the SII. The intensity, the areas, and the percent signal change (PSC) of brain activation that were evoked by different shape ridged textures were related to the geometric structures of the ridged textures. The more complex the geometric structures of texture are, the larger the intensity, the area, and the PSC in brain activation are. The negative BOLD responses of the ipsilateral sensory cortex that were evoked by the flat ridged texture indicated the ipsilateral neuronal inhibition within the sensory systems. The bilateral precuneus, the superior parietal gyrus, and the inferior parietal gyrus, corresponding with the functional areas of the SII (BA40) and the SSA(BA7), were involved in the tactile discriminate of the differences in shapes of ridged textures. The differences in brain activation were related to the differences in geometric structures of the ridged texture. The larger the differences in geometric structure of texture are, the larger the differences in brain activation are. This study revealed the activated location of brain related to the tactile stimulation of different edge shape of ridged textures and the relationship between the geometric structures of ridged texture and brain activities. This research contributes to optimize surface tactile characteristics on products, especially effective surface textures design for good grip.

The emission characteristics of particulate matters from a full-scale biomass-fired power plant equipped with bag filters were investigated. Results show that particle size distribution at the inlet of bag filter from the combustion of blended feedstocks is bimodal, while that of dry bark feedstocks is essentially unimodal with negligible emission of coarse particles with diameter in the range of 1.0–10 μm. The combustion of blended fuels generates higher yields of submicro particles than that of dry bark feedstocks. Elemental analysis shows that submicro particles in all cases mainly consist of potassium, chlorine, and sulfur. Higher chlorine but lower sulfur contents are observed in submicro particles from blended fuels compared with that from dry bark feedstocks. The vibrating operation of grate furnace reduces submicro particles emission as well as the sulfur content in all particles. Ion chromatography results show that sulfate ion and chloridion are the two most abundant water-soluble anions in particulate matters, while water-soluble cations are richest in potassium with considerable content of calcium, magnesium, sodium and ammonia. The contribution of organic and element carbon in particulate matters is in the range of 1–3%, indicating high combustion efficiencies and low organic and element carbon emissions of biomass-fired grate furnaces.

Soot formed during high temperature pyrolysis or incomplete combustion, has strong effects on human health and the environment, as well as radiation heat transfer during combustion. Most studies on soot formation are focused on gas combustion, while the studies of soot formation during solid fuel combustion are rarely reported. In this study, the formation and properties of soot particles from coal pyrolysis are investigated in a drop tube furnace at 1000–1300 °C. The soot morphology, number size distribution, ignition characteristics, gas composition and soot-ash composition were characterized with transmission electron microscopy, scanning mobility particle sizer, thermogravimetric analyzer, gas chromatography, and energy disperse spectroscopy. The effect of coal rank on soot formation and yield is mainly discussed. The results show that with the increase of pyrolysis temperature, the soot yield increases. The soot yields show no dependent relationship with the coal ranks. Among the five kinds of coal tested (anthracite, lean coal, bituminous coal, lignite, and high sodium coal), bituminous coal has a much higher soot yield (>7.5%) than that of other coals (0.5–2%). The oxidation reactivity of soot particles from high sodium coal pyrolysis is much higher than that from other coals, because of the high contents of alkali and alkaline earth metals in soot particles.

Objective To investigate postoperative functional connectivity alterations across impaired cognitive domains and their causal relationships with systemic inflammation. Background Postoperative cognitive dysfunction commonly occurs after cardiac surgery, and both systemic and neuroinflammation may trigger its development. Whether functional connectivity alterations underlying deficits in specific cognitive domains after cardiac surgery are affected by inflammation remain unclear. Methods Seventeen patients, who underwent cardiac valve replacement, completed a neuropsychological test battery and brain MRI scan before surgery and on days 7 and 30 after surgery compared to age-matched healthy controls. Blood samples were taken for TNF-α and IL-6 measurements. Seed-to-voxel FC of the left dorsolateral prefrontal cortex (DLPFC) was examined. Bivariate correlation and linear regression models were used to determine the relationships among cognitive function, FC alterations and cytokines. Results Executive function was significantly impaired after cardiac surgery. At day 7 follow-up, the surgical patients, compared to the controls, demonstrated significantly decreased DLPFC functional connectivity with the superior parietal lobe and attenuated negative connectivity in the default mode network, including the angular gyrus and posterior cingulate cortex. The left DLPFC enhanced the connectivity in the right DLPFC and posterior cingulate cortex, all of which were related to the increased TNF-α and decreased executive function up to day 7 after cardiac surgery. Conclusions The decreased functional connectivity of executive control network and its anticorrelation with the default mode network may contribute to executive function deficits following cardiac surgery. Systemic inflammation may trigger these transient FC changes and executive function impairments.

To understand the effects of biomass origin and temperature on the characteristics of soot formation from biomass, fast pyrolysis of wheat straw and sawdust was performed in an entrained flow react...

The sulfation process during biomass combustion and cofiring, by converting KCl into K2SO4, can affect particulate matter (PM) formation, ash deposition, and corrosion in a furnace. In this study, the effects of temperature, SO2 concentration, O2 concentration, and oxy-combustion atmosphere on the sulfation and PM formation were investigated in an entrained flow reactor. Results show that the particle size distribution (PSD) of PM10 from biomass combustion is bimodal and that PM10 is dominated by PM1.0 consisting of KCl and K2SO4. Enhanced sulfation by SO2 addition generally increases the particle size of PM1.0 and the K2SO4 content in PM1.0, but its effect on PM1.0–10 is marginal. The effect of sulfation on PM1.0 formation strongly depends on the temperature: at high temperature (e.g., 1300 °C), sulfation is not favorable, thereby having negligible influence on PM1.0 formation; while at moderate temperature (e.g., 1100 °C), sulfation is significantly promoted, resulting in a larger size and higher yield ...

Soot particles from biomass incomplete combustion, as a major source of particulate matter, arouse significant concerns due to its harmful impacts on environment and human health. In this paper, the effects of pyrolysis temperature, volatile residence time and water-leaching of biomass on soot formation during biomass pyrolysis were studied in a lab-scale furnace. The physicochemical characteristics of soot particles were comprehensively analyzed. Results show that soot is formed by the secondary reactions of volatiles from biomass thermal-cracking requiring a certain high temperature and long volatile residence time. With a short volatile residence time of 0.2 s, no soot is formed at 900–1200 °C. When the residence time increases to 2 s, soot is significantly formed at >1000 °C, when onion-like shell/core structures is observed. With pyrolysis temperature increasing, the soot particle size decreases and becomes uniform, the carbon content in soot increases, and the ordered structure of carbonization is enhanced, which leads to the degradation of soot oxidation reactivity. The water-leaching pretreatment for biomass leads to the increases of soot yield, particle size, and carbon content, as well as the KCl absence in soot and significantly lowered oxidation reactivity of soot. This indicates strong catalysis of potassium on soot production and consumption. Both gas and tar analyses support soot formation mechanism: (1) H2 yield increases due to formation of soot, but C2H2 yield reaches peak at 1000–1100 °C; (2) tar is dominated by PAHs, which molecules grow with the increase of temperature and residence time.

The desulfurized flue gas from coal-fired power plants is discharged with pollutants and a lot of heat and water vapor into the environment. To synchronously reduce the pollutant emission and recover the heat and water, a novel technology was proposed and applied in a coal-fired power plant after experimental and pilot studies. The technology, referred to as phase transition agglomeration system (PTAS), was developed based on condensational growth and subsequently enhanced removal of particles and droplets under supersaturated conditions. Unlike existing research, the supersaturation here is produced by cooling the desulfurized flue gas through an appropriate approach, which is more feasible for industrial application. Meanwhile, heat and water are recovered. Field measurements were conducted to study its performance. Particle removal efficiencies of the full-scale PTAS were 53.05% and 71.11% at 90% and 75% loads, respectively, and the emission concentrations were reduced to below 5 mg/m3. SO3 removal efficiency was nearly 20% at the initial concentration of ~2.9 mg/m3. >87% of the heat released by the flue gas and over 83% of the condensate were recovered. The recovered heat was utilized directly to heat the feed water of boiler, and the recovered water could be used to replenish the desulfurization slurry after alkali treatment. The heat and water recovery rates were up to 3.59 MW and 4.32 t/h, respectively, which improved the economics of the power plant. The good performance of PTAS in particle and SO3 removal, together with heat and water recovery, was demonstrated in this full-scale study, and worthwhile data and experiences were provided for the development of such technologies for further treatment of coal-fired flue gases.

The utilization of biomass energy is attracting worldwide attention due to the worsening energy crisis and the concerns on carbon dioxide emission. However, the rapidly development of biomass-fired power plants generate enormous amount of slag and ash. At present, the main treatment method of biomass slag and ash is landfill, which not only requires high cost, but also causes a series of environmental issues. Aiming at this problem, the slag and fly ash from four biomass power plants were sampled and characterized. The major/trace element composition and leaching characteristics of slag and fly ash are analyzed, and the effect of volatile mineral in these solid residues on furnace efficiency is also evaluated. The results indicate that for biomass-fired grate furnaces, in the generated solid residues, the slag accounts 60 ~ 70% while the fly ash accounts for 30 ~ 40%. The volatile elements in slag are much lower than those in fly ash, and the unburned carbon content of fly ash is generally lower than that of slag. Due to the enrichment of volatile minerals in fly ash, instead of 815 °C, 550 °C is suggested to measure the unburned carbon content in fly ash. When the measuring temperature of unburned carbon decreases from 815 °C to 550 °C, the measured energy loss from the incomplete combustion of solid fuels decreases by one third, which affords a more reasonable evaluation on combustion efficiency. The contents of cadmium and lead in certain fly ash samples exceed the standard, however, all fly ash samples have a high leaching rate of potassium but low leaching rates of copper, zinc, cadmium, lead, chromium and arsenic. It indicates that the fly ash from biomass-fired grate furnace is suitable for producing potassium fertilizer by leaching instead of direct soil fertilization or landfill. The leaching rate of most minerals in slag is much lower than that in fly ash and the contents of heavy metals are far below the prescribed upper limit in standard, which indicates that the slag from biomass-fired grate boiler is more suitable for direct use in soil improvement due to the low contents of hazardous elements.

Low-temperature pyrolysis is one of the most promising methods for lignite upgrading and staged utilization, however, its effect on particulate matter emissions from the combustion of upgrad lignite has not been reported before. In this paper, Xilin Gol lignite was pyrolyzed in a fixed-bed reactor at 250–550 °C, the produced semi-char was characterized, and then burned in a drop tube furnace at 1300 °C. Particulate matter emissions from lignite semi-char combustion are collected and measured passing through a 13- stage impactor. Results show that the particulate matter emissions of lignite combustion can be significantly affected through the change of fuel properties by low- temperature pyrolysis upgrading. In the studied pyrolysis temperature range, the most drastic devolatilization, fragmentation, porous structure development, and removal of reactive functional group occur at about 350 °C, when the produced semi-char has the highest combustion reactivity. With the increase of pyrolysis temperature, both emissions of particulate matter

Advanced carbon material production via pyrolysis is an economical process for the recycling-utilization of waste plastics. The purpose of this study is to demonstrate the characteristics and formation mechanism of nano-scale soot particles from waste plastic pyrolysis at high temperatures. Waste rigid polyurethane (PU) was adopted to decompose in an entrained flow reactor at 1000, 1100, 1200, and 1300 °C. The yield, morphology, elemental composition, chemical and crystal structure, and reactivity of soot particles, and the yield and composition of gas products were measured and characterized. Results show that with the temperature increasing from 1000 to 1200 °C, the soot yield increases from 12.2 to 26.5 wt%, while with the temperature increasing to 1300 °C, the change on soot yield is slight. The morphology analysis by scanning transmission electron microscopy indicates that the inception of soot particles starts at 1100 °C, when the onion layered structure of spherical particles (20–50 nm) is observed. With increased temperature, the soot particle size becomes smaller and more uniform. Fourier transform infrared analysis and X-ray diffraction characterization present more C=C functional groups and better graphite structures at higher temperatures, agreeing with the increased carbon content in soot. The oxidation reactivity of soot particles generally increased with the increase of pyrolysis temperature. NaCl is observed in soot particles when the pyrolysis temperature is higher than 1100 °C, as an efficient catalyst, significantly enhances the ignition and burnout of soot particles. The soot formation pathway during plastic pyrolysis is finally proposed based on the measurement of representative gases.

Soot is an important toxic pollutant generated during high-temperature incineration of solid waste (i.e., biomass and plastic waste) under air-lean conditions, and has a great impact on flame radiation. The main objective of this work is to study the synergistic effect of biomass and polyurethane co-pyrolysis on soot formation at high temperatures (1100–1250 °C). The effects of temperature, biomass species, and co-pyrolysis ratio on the yield, morphology, composition and reactivity of soot particles are studied. Results show that under controlled co-pyrolysis conditions, the measured soot yield from co-pyrolysis of biomass and polyurethane is lower than the theoretical value by weight average, while the particle size distribution tends to concentrate on a smaller diameter range. The degree of synergistic effect increases with the increasing biomass ratio (0–50 wt%) and decreasing pyrolysis temperature. Wood in co-pyrolysis presents a stronger synergistic effect on soot yields than straw co-pyrolysis does. Degree of synergistic effect on soot oxidation reactivity depends much on the biomass addition ratio but less on pyrolysis temperature. At 10 wt% straw addition ratio, co-pyrolysis exerts a negative synergistic effect on soot oxidation reactivity, while the synergistic effect turns significantly positive when the straw addition ratio increases to 50 wt%.