Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 50
Filter
1.
Chemosphere ; 351: 141251, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38253084

ABSTRACT

This study presents the catalytic pyrolysis of microalgae, Chlorella vulgaris (C. vulgaris), using pure CH4 and H2-rich gas evolved from CH4 decomposition on three different HZSM-5 catalysts loaded with Zn, Ga, and Pt, aimed specifically at producing high-value mono-aromatics such as benzene, toluene, ethylbenzene, and xylene (BTEX). In comparison with that for the typical inert N2 environment, a pure CH4 environment increased the bio-oil yield from 32.4 wt% to 37.4 wt% probably due to hydrogen and methyl radical insertion in the bio-oil components. Furthermore, the addition of bimetals further increased bio-oil yield. For example, ZnPtHZ led to a bio-oil yield of 47.7 wt% in pure CH4. ZnGaHZ resulted in the maximum BTEX yield (6.68 wt%), which could be explained by CH4 activation, co-aromatization, and hydrodeoxygenation. The BTEX yield could be further increased to 7.62 wt% when pyrolysis was conducted in H2-rich gas evolved from CH4 decomposition over ZnGaHZ, as rates of aromatization and hydrodeoxygenation were relatively high under this condition. This study experimentally validated that the combination of ZnGaHZ and CH4 decomposition synergistically increases BTEX production using C. vulgaris.


Subject(s)
Chlorella vulgaris , Microalgae , Plant Oils , Polyphenols , Hot Temperature , Pyrolysis , Toluene , Benzene , Xylenes , Catalysis , Zinc , Biofuels
2.
Gait Posture ; 107: 212-217, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37863672

ABSTRACT

BACKGROUND: Gait assessment has been used in a wide range of clinical applications, and gait velocity is also a leading predictor of disease and physical functional aspects in older adults. RESEARCH QUESTION: The study aim to examine the changes in IMU-based gait parameters according to age in healthy adults aged 50 and older, to analyze differences between aging patients. METHODS: A total of 296 healthy adults (65.32 ± 6.74 yrs; 83.10 % female) were recruited. Gait assessment was performed using an IMU sensor-based gait analysis system, and 3D motion information of hip and knee joints was obtained using magnetic sensors. The basic characteristics of the study sample were stratified by age category, and the baseline characteristics between the groups were compared using analysis of variance (ANOVA). Pearson's correlation analysis was used to analyze the relationship between age as the dependent variable and several measures of gait parameters and joint angles as independent variables. RESULTS: The results of this study found that there were significant differences in gait velocity and both terminal double support in the three groups according to age, and statistically significant differences in the three groups in hip joint angle and knee joints angle. In addition, it was found that the gait velocity and knee/hip joint angle changed with age, and the gait velocity and knee/hip joint angle were also different in the elderly and adult groups. CONCLUSIONS: We found changes in gait parameters and joint angles according to age in healthy adults and older adults and confirmed the difference in gait velocity and joint angles between adults and older adults.


Subject(s)
Gait Analysis , Gait , Aged , Humans , Female , Middle Aged , Male , Cross-Sectional Studies , Biomechanical Phenomena , Knee Joint
3.
J Hazard Mater ; 451: 131101, 2023 06 05.
Article in English | MEDLINE | ID: mdl-36878030

ABSTRACT

Phytoremediation of metals from water (WM) and nutrient (NM) media exposed to waste metal cutting fluid (WMCF) along with temperature (T) and humidity (H) stress was tested using Azolla imbricata (Roxb.) Nakai. In the absence of WMCF, biomass was higher in NM than in WM during all tests. Surprisingly, opposite results were noted in the presence of WMCF, with growth failing at exposure to > 0.1% and > 0.5% in NM and WM, respectively. Further, correlation analysis of the growth data following WM exposure revealed that biomass was affected positively by T and negatively by H and metal accumulation. Simultaneously, metal accumulation was affected negatively by T and positively by H. The average accumulations of Al, Cd, Cr, Fe, Pb, and Zn across all T/H tests were 540, 282, 71, 1645, 2494 and 1110 mg·kg-1, respectively. The observed bioconcentration factor indicated that A. imbricata acts as a hyperaccumulator or accumulator of Zn (>10) and as either accumulator (>1) or excluder (<1) of the other metals. Overall, the phytoremediation performance of A. imbricata in multi-metal-contaminated WMCF was high in WM under all environmental conditions. Therefore, the use of WM is an economically feasible approach for the removal of metals from WMCF.


Subject(s)
Metals, Heavy , Soil Pollutants , Metals, Heavy/analysis , Biodegradation, Environmental , Humidity , Temperature , Water/analysis , Soil Pollutants/analysis
4.
Chemosphere ; 287(Pt 2): 132224, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34826918

ABSTRACT

Food waste, a renewable resource, was converted to H2-rich gas via a catalytic steam gasification process. The effects of basic oxides (MgO, CaO, and SrO) with 10 wt% Ni/Al2O3 on the gasification properties of food waste were investigated using a U-shaped gasifier. All catalysts prepared by the precipitation method were analyzed by X-ray diffraction, H2-temperature-programmed reduction, NH3-temperature-programmed desorption, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The Ni/Al2O3 catalyst was reduced incompletely, and low nickel concentrations were detected on the surface of the alumina. The basic oxides minimized the number of acid sites and suppressed the formation of nickel-aluminate (NiAlxOy) phase in catalyst. In addition, the basic oxides shifted nickel-aluminate reduction reaction to lower temperatures. It resulted in enhancing nickel concentration on the catalyst surface and increasing gas yield and hydrogen selectivity. The low gas yield of the Ni/Al2O3 catalyst was attributed to the low nickel concentration on the surface. The maximum gas yield (66.0 wt%) and hydrogen selectivity (63.8 vol%) of the 10 wt% SrO- 10 wt% Ni/Al2O3 catalyst correlated with the highly dispersed nickel on the surface and low acidity. Furthermore, coke deposition during steam gasification varied with the surface acidity of the catalysts and less coke was formed on 10 wt% SrO- 10 wt% Ni/Al2O3 due to efficient tar cracking. This study showed that the steam gasification efficiency of the Ni/Al2O3 catalyst could be improved significantly by the addition of SrO.


Subject(s)
Refuse Disposal , Steam , Biomass , Food , Hydrogen , Magnesium Oxide , Oxides
5.
ACS Omega ; 6(44): 29703-29712, 2021 Nov 09.
Article in English | MEDLINE | ID: mdl-34778642

ABSTRACT

Direct interspecies electron transfer (DIET) is a breakthrough that can surpass the limitations of anaerobic digestion. Conductive materials and polarized bioelectrodes are known to induce DIET for methane production but are still challenging to apply at a field scale. Herein, compared to polarized bioelectrodes, electrostatic fields that promote DIET were investigated in an anaerobic reactor with conductive materials. As a conductive material, activated carbon enriched its surface with electroactive microorganisms to induce DIET (cDIET). cDIET improved the methane yield to 254.6 mL/g CODr, compared to the control. However, polarized bioelectrodes induced electrode-mediated DIET and biological DIET (bDIET), in addition to cDIET, improving the methane yield to 310.7 mL/g CODr. Electrostatic fields selectively promoted bDIET and cDIET for further methane production compared to the polarized bioelectrodes. As the contribution of DIET increased, the methane yield increased, and the substrate residue decreased, resulting in a significant improvement in methane production.

6.
Sensors (Basel) ; 21(22)2021 Nov 19.
Article in English | MEDLINE | ID: mdl-34833761

ABSTRACT

Gait disturbance is a common sequela of stroke. Conventional gait analysis has limitations in simultaneously assessing multiple joints. Therefore, we investigated the gait characteristics in stroke patients using hip-knee cyclograms, which have the advantage of simultaneously visualizing the gait kinematics of multiple joints. Stroke patients (n = 47) were categorized into two groups according to stroke severity, and healthy controls (n = 32) were recruited. An inertial measurement unit sensor-based gait analysis system, which requires placing seven sensors on the dorsum of both feet, the shafts of both tibias, the middle of both femurs, and the lower abdomen, was used for the gait analysis. Then, the hip-knee cyclogram parameters (range of motion, perimeter, and area) were obtained from the collected data. The coefficient of variance of the cyclogram parameters was obtained to evaluate gait variability. The cyclogram parameters differed between the stroke patients and healthy controls, and differences according to stroke severity were also observed. The gait variability parameters mainly differed in patients with more severe stroke, and specific visualized gait patterns of stroke patients were obtained through cyclograms. In conclusion, the hip-knee cyclograms, which show inter-joint coordination and visualized gait cycle in stroke patients, are clinically significant.


Subject(s)
Hemiplegia , Stroke , Biomechanical Phenomena , Gait , Humans , Knee , Knee Joint
7.
Sensors (Basel) ; 21(15)2021 Jul 24.
Article in English | MEDLINE | ID: mdl-34372258

ABSTRACT

Exercise intensity of exoskeleton-assisted walking in patients with spinal cord injury (SCI) has been reported as moderate. However, the cardiorespiratory responses to long-term exoskeleton-assisted walking have not been sufficiently investigated. We investigated the cardiorespiratory responses to 10 weeks of exoskeleton-assisted walking training in patients with SCI. Chronic nonambulatory patients with SCI were recruited from an outpatient clinic. Walking training with an exoskeleton was conducted three times per week for 10 weeks. Oxygen consumption and heart rate (HR) were measured during a 6-min walking test at pre-, mid-, and post-training. Exercise intensity was determined according to the metabolic equivalent of tasks (METs) for SCI and HR relative to the HR reserve (%HRR). Walking efficiency was calculated as oxygen consumption divided by walking speed. The exercise intensity according to the METs (both peak and average) corresponded to moderate physical activity and did not change after training. The %HRR demonstrated a moderate (peak %HRR) and light (average %HRR) exercise intensity level, and the average %HRR significantly decreased at post-training compared with mid-training (31.6 ± 8.9% to 24.3 ± 7.3%, p = 0.013). Walking efficiency progressively improved after training. Walking with an exoskeleton for 10 weeks may affect the cardiorespiratory system in chronic patients with SCI.


Subject(s)
Exoskeleton Device , Spinal Cord Injuries , Gait , Humans , Oxygen Consumption , Walking
8.
Chemosphere ; 280: 130671, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34162076

ABSTRACT

The disposal of food waste (FW) is a major cause of environmental contamination. This study reports an environmentally friendly FW disposal method in the form of catalytic steam gasification using various types of Ni-loaded chars (untreated char, steam-treated char, and ZnCl2-treated char). The results were also compared with the gasification results from the Ni catalysts supported on commercial α-alumina (Ni/α-Al2O3). The Ni/steam-treated char showed the maximum hydrogen generation (0.471 mol/(g feedstock•g cat)) because of the high reducibility, high nickel dispersion, large amount of inherent K and Ca, and moderate surface area. The overall gas and H2 yield were observed in the following order: Ni/steam-treated char > Ni/ZnCl2 treated char > Ni/untreated char > Ni/α-Al2O3. Brunauer-Emmett-Teller analysis of various catalysts showed that the treated chars have a mesoporous structure, and the X-ray diffraction, X-ray fluorescence spectroscopy, scanning electron microscopy - energy dispersive spectroscopy showed that the presence of silica in the chars providing the stable support for the Ni loading and prevented coke formation. The chars obtained from biomass pretreatment could be a potential solution for preventing coke formation at high temperatures, thereby increasing the gas yield and enhancing hydrogen generation.


Subject(s)
Oryza , Refuse Disposal , Biomass , Catalysis , Charcoal , Food , Hydrogen/metabolism , Steam
9.
Medicine (Baltimore) ; 100(21): e25823, 2021 May 28.
Article in English | MEDLINE | ID: mdl-34032696

ABSTRACT

ABSTRACT: Sexual dysfunction is a common problem after cerebral infarction; however, little is known about sexual arousal in poststroke patients. Thus, this study aimed to investigate brain activation in response to visual sexual stimuli in patients with right middle cerebral artery (MCA) territory infarction using functional magnetic resonance imaging (fMRI). Using fMRI in 20 participants (11 right MCA infarction patients and 9 age-matched healthy controls), we assessed brain activation elicited by visual sexual stimuli (erotic images) and visual nonsexual stimuli (landscape images). In right MCA infarction patients, the left dorsolateral prefrontal cortex and the left frontal subgyral area were more strongly activated by visual sexual stimuli than by nonvisual sexual stimuli. Brain areas that were more activated by visual sexual stimuli in right MCA infarction patients than in controls included the right parahippocampal gyrus and the bilateral frontal subgyral area. These fMRI results suggest that brain activation patterns in response to visual sexual stimuli might be influenced by right MCA infarction. Further research is needed to explore the association between sexual dysfunction and brain activation in poststroke patients.


Subject(s)
Brain/physiopathology , Infarction, Middle Cerebral Artery/complications , Sexual Behavior/physiology , Sexual Dysfunction, Physiological/physiopathology , Visual Perception/physiology , Adult , Aged , Brain/blood supply , Brain/diagnostic imaging , Brain Mapping , Case-Control Studies , Erotica , Humans , Infarction, Middle Cerebral Artery/physiopathology , Magnetic Resonance Imaging , Male , Middle Aged , Photic Stimulation/methods , Sexual Dysfunction, Physiological/etiology
10.
Environ Pollut ; 289: 117311, 2021 Nov 15.
Article in English | MEDLINE | ID: mdl-34015691

ABSTRACT

Studies in the literature concern the toxicity of nanoparticles either in a Petri dish or in agar media-based tests. Therefore, for environmental relevance, individual and binary mixtures of metal oxide nanoparticles (M-NPs) cadmium oxide (CdO-NP) and copper oxide (CuO-NP) were tested in this study for their effect on Vigna radiata in soil with and without the addition of sawdust. Seed germination was 67% in 100 mg CuO-NP in soil without sawdust. Seeds failed to germinate in 100 mg CdO +100 mg CuO-NPs in soil without the addition of sawdust and germination was 83% at the same concentration in soil with sawdust. In sawdust added to soil, when compared with control (soil without M-NPs), the maximum reduction in shoot (82%) and root (80%) length and wet (61%) and dry (54%) weight of plant was recorded in CdO-NP treated soil. Similarly, compared with control (soil without sawdust and M-NPs), the percent reduction in shoot (61%) and root (70%) length and wet (44%) and dry (48%) weight was highest in CdO-NP treated soil not supplemented with sawdust. In a binary mixture test (CdO-NP + CuO-NP), the addition of sawdust promoted the above plant growth parameters compared with individual CdO-NP and CuO-NP tests. Cadmium (511 mg kg-1 for individual and 303 mg kg-1 for binary mixture tests) and Cu (953 mg kg-1 for individual and 2954 mg kg-1 for binary mixture tests) accumulation was higher in plants grown in soil without sawdust. The beneficial effect of sawdust addition was observed in seed germination, plant growth, and metal accumulation. With or without sawdust, the binary mixture of CdO and CuO was antagonistic. These results indicate that sawdust can prevent M-NP-induced toxicity and reduce metal accumulation in plant tissues.


Subject(s)
Metal Nanoparticles , Nanoparticles , Vigna , Cadmium/toxicity , Copper/toxicity , Metal Nanoparticles/toxicity , Oxides , Seeds
11.
Chemosphere ; 279: 130521, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33866093

ABSTRACT

Biochar was produced by the pyrolysis of Kraft lignin at 600 °C followed by modification with CO2 at 700 and 800 °C and impregnation with FeOx. The physicochemical properties and arsenic (V) adsorption performance of biochar were evaluated. The characteristics of the lignin biochar before and after CO2 modification and FeOx impregnation were analyzed using the following methods: proximate and ultimate analysis, specific surface area (Brunauer-Emmett-Teller (BET) surface area), porosity, scanning electron microscopy and energy dispersive spectroscopy mapping, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. The specific surface area and porosity of biochar were improved significantly after CO2 modification. However, impregnation of FeOx in CO2-modified biochar showed a 50%-60% decrease of BET surface area and porosity due to pore blocking of FeOx. The batch adsorption of arsenic (V) showed that FeOx-LC-800 (FeOx impregnation lignin char modified with CO2 at 800 °C) had the highest adsorption efficiency among the biochars tested because of its highest Fe-O intensity and large surface area. The Langmuir adsorption model was suitable for the curve fitting arsenic (V) adsorption. The theoretical equilibrium adsorption amount (qe) was calculated to be 6.8 mg/g using a pseudo-second-order kinetic model.


Subject(s)
Arsenic , Water Pollutants, Chemical , Adsorption , Carbon Dioxide , Charcoal , Kinetics , Lignin , Water
12.
World J Clin Cases ; 9(5): 1237-1246, 2021 Feb 16.
Article in English | MEDLINE | ID: mdl-33644190

ABSTRACT

BACKGROUND: Isolated musculocutaneous nerve injury is a rare condition. Herein, we report the first case of bilateral musculocutaneous neuropathy after vigorous stretching of both upper extremities with normal results of sensory nerve action potential. Clinicians should be aware of this rare condition that can appear bilaterally. In addition, the interpretation of the aberrant electrodiagnostic study results of this case was discussed. CASE SUMMARY: A 29-year-old male complaining of bilateral forearm tingling and upper extremity weakness visited the outpatient clinic. The symptoms began 6 mo prior, and he visited another hospital before visiting our department. The diagnosis was not made even after cervical spine magnetic resonance imaging, electrodiagnostic study, brain magnetic resonance imaging, and arteriography were conducted. The patient performed unique exercises that stretched the pectoralis minor and coracobrachialis muscles. On the follow-up electrodiagnostic study, abnormal spontaneous activities in the bilateral biceps and brachialis muscles were observed. The patient was diagnosed with bilateral musculocutaneous neuropathy. Steroid pulse therapy was administered for approximately 6 wk. After treatment, his muscle strength returned to the predisease condition. CONCLUSION: Clinicians should be aware of this condition, have adequate understanding of anatomy, and advise to correct inappropriate exercises.

13.
Chemosphere ; 271: 129595, 2021 May.
Article in English | MEDLINE | ID: mdl-33460892

ABSTRACT

Nitrogen-doped magnetic mesoporous hollow carbon (NMMHC) was prepared to realize effective adsorption of phenol from wastewater. The chemical and physical properties of NMMHC were analyzed, and the effects of adsorption time, initial pH, and phenol concentration on the adsorption capacity of NMMHC were studied. Adsorption kinetics and isotherm models were used to explain the adsorption properties. The results showed that the specific surface area, type of nitrogen group, and nitrogen content of NMMHC are related to the carbonization temperature. Chemical interaction was demonstrated to be present in the process of adsorption, which was characterized as monolayer adsorption. In addition, the adsorption mechanism was studied by attenuated total internal reflectance Fourier transform infrared spectroscopy and analysis of non-covalent interactions. This study found that non-covalent interactions between NMMHC and phenol molecules are van der Waals interactions, and nitrogen-containing groups increase the phenol adsorption capacity by enhancing such interactions. The π-π interactions between the nitrogen groups and phenol molecules also enhanced the adsorption energy.


Subject(s)
Nitrogen , Water Pollutants, Chemical , Adsorption , Carbon , Kinetics , Magnetic Phenomena , Phenol , Phenols , Spectroscopy, Fourier Transform Infrared , Wastewater
14.
Sci Rep ; 11(1): 1789, 2021 01 19.
Article in English | MEDLINE | ID: mdl-33469057

ABSTRACT

Inter-joint coordination and gait variability in knee osteoarthritis (KOA) has not been well investigated. Hip-knee cyclograms can visualize the relationship between the hip and knee joint simultaneously. The aim of this study was to elucidate differences in inter-joint coordination and gait variability with respect to KOA severity using hip-knee cyclograms. Fifty participants with KOA (early KOA, n = 20; advanced KOA, n = 30) and 26 participants (≥ 50 years) without KOA were recruited. We analyzed inter-joint coordination by hip-knee cyclogram parameters including range of motion (RoM), center of mass (CoM), perimeter, and area. Gait variability was assessed by the coefficient of variance (CV) of hip-knee cyclogram parameters. Knee RoM was significantly reduced and total perimeter tended to be decreased with KOA progression. KOA patients (both early and advanced) had reduced stance phase perimeter, swing phase area, and total area than controls. Reduced knee CoM and swing phase perimeter were observed only in advanced KOA. Both KOA groups had a greater CV for CoM, knee RoM, perimeter (stance phase, swing phase and total) and swing phase area than the controls. Increased CV of hip RoM was only observed in advanced KOA. These results demonstrate that hip-knee cyclograms can provide insights into KOA patient gait.


Subject(s)
Gait , Hip/physiopathology , Knee/physiopathology , Osteoarthritis, Knee/physiopathology , Aged , Female , Humans , Male , Middle Aged , Severity of Illness Index
15.
Chemosphere ; 264(Pt 1): 128444, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33010630

ABSTRACT

In this study, the concentration of foliar dust and 23 elemental concentrations in foliar dust and foliar tissues were studied using long rows of grand tamarind trees grown in two major roads in Coimbatore, India. Twenty-four sampling sites were chosen and categorized as urban (n = 5), suburban (n = 14), and rural (n = 5) areas based on the local population. In the case of foliar dust concentration, a significant difference was noted between the sites of urban (range between 3.06 and 6.68 µ/cm2) and suburban areas (range between 0.56 and 5.75 µ/cm2) but not for rural areas (range between 0.40 and 0.47 µ/cm2). When comparing the urban, suburban, and rural, either significantly or insignificantly, 17 elements (Al, Ba, Bi, Ca, Cd, Co, Cu, Fe, Ga, In, K, Mg, Mn, Ni, Sr, and Zn) in urban and five elements (Ag, B, Cr, Na, and Pb) in suburban were higher. However, in the case of elements in tamarind laves, almost all elements except Na and K were higher in the urban area. Furthermore, the study results suggest that the elements in both foliage dust and in tamarind leaves are not evenly distributed between the sites of urban, suburban, and rural areas. This uneven distribution might be due to the construction being performed on a stretch of a four-lane highway during sampling, heavy transportation in three small junctions of suburban sites, and a rail over-bridge construction in one suburban site. However, comprehensive studies are needed to confirm this conclusion.


Subject(s)
Metals, Heavy , Tamarindus , Dust/analysis , Environmental Monitoring , India , Metals, Heavy/analysis , Plant Leaves/chemistry
16.
J Hazard Mater ; 403: 123934, 2021 Feb 05.
Article in English | MEDLINE | ID: mdl-33264983

ABSTRACT

Five different Ru-Mn/zeolites were used to investigate their catalytic efficiencies for removing toluene (100 ppm) with ozone (1000 ppm) at room temperature. In general, most of metal oxide catalysts for removal of organic compounds need higher temperature than the ambient temperature, but Mn-based catalysts shows activity for prevalent organic pollutants even at room temperature with ozone. For the removal of toluene at room temperature without further heating, bimetallic Ru added Mn catalysts were applied in combination with different zeolite supports. The catalytic activity of the Ru-Mn catalysts strongly depended on the zeolite, of which the characteristics such as acidity and adsorption degree of toluene are dependent on the ratio of SiO2/Al2O3. Among the five Ru-Mn catalysts used, Ru-Mn/HY (SiO2/Al2O3 ratio: 80) and Ru-Mn/ZSM-5 (SiO2/Al2O3 ratio: 80) had higher toluene and ozone removal efficiencies. The toluene removal efficiency of Ru-Mn/zeolites was proportional to the pore volume and surface area. In terms of ozone degradation, Ru-Mn/HY(80) and Ru-Mn/HZSM-5(80) had the highest removal efficiencies. Overall, the catalytic ozone oxidation of toluene using Ru-Mn/zeolites seemed to be affected by a combination of the acidic properties of zeolites, Mn3+/Mn4+ ratio, and concentration ratio of oxygen vacancies to oxygen lattices on the catalyst surface.

17.
Environ Res ; 191: 110149, 2020 12.
Article in English | MEDLINE | ID: mdl-32882239

ABSTRACT

In this study, red mud (RM), a highly alkaline waste generated from alumina production industries, was used as a catalytic material for both fast copyrolysis of organosolv lignin (OL) and polypropylene (PP) and toluene removal under ozone at room temperature. The RM was pretreated with HCl to investigate the effect of alkalinity. In the catalytic fast copyrolysis of the OL and PP, the acid-treated RM (HRM) produced more aromatics, phenolics, and light olefins (C3 to C5) but less oxygenates and heavy olefins (C6 to C46) than the RM. The difference in pyrolytic performance between the RM and HRM was likely attributed to the concentrated Fe2O3 species in the HRM catalyst. In addition, more efficient toluene removal was observed over MnOx/HRM than over MnOx/RM owing to the large Brunauer-Emmett-Teller surface area, high amounts of Al and Fe, and optimal Mn3+/Mn4+ ratio. This study demonstrates that the RM, an industrial waste, can be reused as an effective catalytic material for not only biofuel production but also pollutant removal.


Subject(s)
Ozone , Catalysis , Industrial Waste , Lignin , Toluene
18.
Australas Emerg Care ; 23(4): 272-280, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32646835

ABSTRACT

BACKGROUND: This study is aimed to identify the muscles that need to be trained for high-quality cardiopulmonary resuscitation by evaluating the muscles that are fatigued during chest compression in both kneeling and standing positions. METHODS: In this randomized crossover trial, 37 participants performed continuous chest compressions on a manikin for 5min, alternating between kneeling and standing positions. The median frequency values of 16 muscles were determined from surface electromyography recordings. RESULTS: The median frequency values of the arm muscles (flexor carpi radialis, extensor carpi radialis, biceps brachii, triceps brachii) in both positions were significantly lower during the last 30s than during the first 30s, demonstrating muscle fatigue over time. The cervical erector spinae in the kneeling position and the external oblique abdominis in the standing position were also fatigued over time. In the deltoideus, quadriceps femoris, and biceps femoris muscles, the difference in median frequency between the last 30s and the first 30s was significantly different between the two positions, and muscles were more fatigued in the standing position than in the kneeling position. CONCLUSIONS: Understanding patterns of muscle fatigue and training of these muscles would assist healthcare providers in performing high-quality chest compressions. ClinicalTrials.gov number: NCT02088879.


Subject(s)
Cardiopulmonary Resuscitation/methods , Muscles/physiology , Physical Fitness/physiology , Adult , Cross-Over Studies , Electromyography/instrumentation , Electromyography/methods , Female , Humans , Male , Manikins , Republic of Korea
19.
J Hazard Mater ; 397: 122581, 2020 10 05.
Article in English | MEDLINE | ID: mdl-32417605

ABSTRACT

This study focused on the simultaneous removal of NO and SO2 from an industrial flue gas stream. To evaluate the removal efficiency of NO and SO2 using O3 and NH3, the consumption of two reactants (O3 and NH3) in line with the conversion of NO and SO2 was quantified experimentally. In addition, NO and SO2 were converted to valuable fertilizers, NH4NO3 and (NH4)2SO4. To identify a principle strategy to enhance the generation of fertilizer, Fourier transform infrared spectroscopy was used to examine the reaction mechanisms for the formation of NH4NO3 and (NH4)2SO4. Acceleration of SO2 oxidation could be achieved effectively by adding NO to a gas mixture of SO2, NH3, and O3. The formation of HNO3 might be enhanced by the simultaneous feeding of NO and SO2. Particle generation was also 10 times higher for NH3/(NO + SO2) than for NH3/NO and for NH3/SO2, which is a prominent feature of this study. Moreover, the introduction of steam had a positive influence on particle generation. This method offers dual applications for NO and SO2 removal from a flue gas stream and direct fertilizer generation.

20.
Environ Res ; 184: 109311, 2020 05.
Article in English | MEDLINE | ID: mdl-32145550

ABSTRACT

Catalytic co-pyrolysis (CCP) of spent coffee ground (SCG) and cellulose over HZSM-5 and HY was characterized thermogravimetrically, and a catalytic pyrolysis of two samples was conducted using a tandem micro reactor that directly connected with gas chromatography-mass spectrometry. To access the more fundamental investigations on CCP, the effects of the zeolite pore structure, reaction temperature, in-situ/ex-situ reaction mode, catalyst to feedstock ratio, and the SCG and cellulose mixing ratio were experimentally evaluated. The temperature showing the highest thermal degradation rate of cellulose with SCG slightly delayed due to the interactions during the thermolysis of two samples. HZSM-5 in reference to HY produced more aromatic hydrocarbons from CCP. With respect to the reaction temperature, the formation of aromatic hydrocarbons increased with the pyrolytic temperature. Moreover, the in-situ/ex-situ reaction mode, catalyst/feedstock, and cellulose/SCG ratio were optimized to improve the aromatic hydrocarbon yield.


Subject(s)
Biofuels , Cellulose , Pyrolysis , Catalysis , Coffee , Hot Temperature
SELECTION OF CITATIONS
SEARCH DETAIL
...