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1.
Bioresour Technol ; 304: 123064, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32115346

RESUMEN

In this study, a novel psychrotrophic lignocelluloses degrading microbial consortium LTF-27 was successfully obtained from cold perennial forest soil by successive enrichment culture under facultative anaerobic static conditions. The microbial consortium showed efficient degradation of rice straw, which cellulose, hemicelluloses and lignin lost 71.7%, 65.6% and 12.5% of its weigh, respectively, in 20 days at 15 °C. The predominant liquid products were acetic acid and butyric acid during degrading lignocellulose in anaerobic digestion (AD) process inoculated with the LTF-27. The consortium mainly composed of Parabacteroides, Alcaligenes, Lysinibacillus, Sphingobacterium, and Clostridium, along with some unclassified uncultured bacteria, indicating powerful synergistic interaction in AD process. A multi-species lignocellulolytic enzyme system working cooperatingly on lignocelluolse degradation was revealed by proteomics analysis of cellulose bound fraction of the crude extracellular enzyme, which provides key theoretical base for further exploration and application of LTF-27.


Asunto(s)
Consorcios Microbianos , Oryza , Bacterias , Celulosa , Lignina , Temperatura Ambiental
2.
Bioresour Technol ; 304: 123026, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32127244

RESUMEN

The potential of low-cost bioenergy recovery from peanut shell was limited for its complex cellulose structure. In order to enhance the total reducing sugar (TRS) yield for bio-H2 production, peanut shell with heat (HT, 50-100 °C) or freezing pretreatment (FT, -80 to 0 °C) under different duration (0.5-12 h) was investigated. For uncovering the enhancement mechanisms, morphological feature and crystalline structure were analyzed by scanning electron microscope (SEM) and X-ray powder diffraction (XRD). The optimal pretreatment of 50 °C for 12 h was obtained with TRS yield increased 73.6%, while the H2 yield of 1.25 ml/mg-TRS was peaked with pretreatment at -80 °C. The SEM and XRD further demonstrated that mechanisms of HT and FT were realized through different ways, which were cracking and collapsing in HT, and delamination and peeling in FT, respectively.


Asunto(s)
Arachis , Celulosa , Hidrólisis , Temperatura Ambiental , Difracción de Rayos X
3.
J Environ Manage ; 261: 110190, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148266

RESUMEN

Quality of soils of the arid zones with low organic matter can be improved through the application of natural amendments especially biochar from various available feedstocks. The objective of this study was to evaluate the impacts of corn residue and poultry manure and their biochars on soil organic carbon (SOC), hot-water soluble carbohydrates (HWSC), basal soil respiration (BSR),and structural stability determined by HEMC (high-energy moisture characteristic). A sandy loam soil in pots were thoroughly mixed with 1, 2 and 4% w/w of corn residues (CR) and poultry manure (PM) feedstock and their biochars prepared at 350 and 650 °C of slow pyrolysis. Maize seeds were planted in pots and grown until physiological maturity when soil characteristics were measured. Treatments considerably altered the means of studied soil quality indicators, and increased SOC (1.5-10 times) and HWSC (1-7 times), and HEMC indices: volume of drainable pores ratio (VDPR, 1.5- 3.5 times), and stability ratio (SR, 1-3 times). Increasing pyrolysis temperature, regardless of the type and rate of feedstock, significantly decreased the SOC, BSR and percent of water-stable aggregates, and consequently structural stability indices. Contribution of both PM feedstock and its biochars was less effective than the CR ones (particularly the biochar produced at higher pyrolysis temperature), due to elevated sodium adsorption ratio (SAR) associated with higher slaking, physico-chemical dispersion and lower aggregate and structural stability.


Asunto(s)
Carbono , Suelo , Animales , Carbón Orgánico , Pirólisis , Temperatura Ambiental
4.
J Environ Manage ; 261: 110228, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148298

RESUMEN

Temporal and spatial continuity of remote sensing data is flawed due to cloudiness, sensor malfunction or atmospheric pollution. Different methods have been presented to estimate missing values in remote sensing data. In this study, we evaluate the performance of a spatio-temporal gap filling algorithm developed by Weiss et al. (2014). This algorithm is interesting and worthy for further evaluation because it achieves high accuracy while maintaining the computational complexity considerably low. To conduct a comprehensive evaluation, we applied the algorithm to MODIS (Land Surface Temperature (LST) and evapotranspiration (ET)) and TRMM (precipitation) time series and investigate the effects of several factors including seasonality, variable type, gap size and surface characteristics through simulation scenarios. The performances were discussed using qualitative and quantitative assessments based on different simulation scenarios. A crucial finding of this study is a subtle structural deficiency of the algorithm. In particular, the algorithm outputs highly erroneous estimations when dealing with pixels with values mostly between zero and one. Such unexpected errors were observed in the seasonal assessment of land surface temperature estimations. In addition, according to the results of this study, the algorithm was sensitive to the variable type; however there was no correlation between the studied gap sizes and the error values. Among the three studied variables, LST and ET missing values were restored very accurately while estimations of precipitation missing values were more erroneous. The results also exhibit that in heterogeneous areas with complex topography, the errors of estimations were higher than homogeneous regions and areas with less complex topography. Based on the results, the algorithm should be used with caution in the discrete parameters like precipitation and area with abrupt variations. Furthermore, the design of the method may be refined for such datasets which include values with range between zero and one.


Asunto(s)
Algoritmos , Temperatura Ambiental
5.
J Environ Manage ; 261: 110232, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148302

RESUMEN

To protect fragile groundwater-dependent environments of arid zones, it is important to monitor soil moisture and groundwater evaporation. Hence, it is important to assess new methods to quantify these environmental variables. In this work, we propose a new method to determine groundwater evaporation rates by combining the actively heated fiber-optic (AHFO) method with vadose zone modeling, assuming that the evaporation front remains at the soil surface. In our study, the AHFO method yielded estimates of the soil moisture (θ) profile with a spatial resolution of ~6.5 mm and with an error of 0.026 m3 m-3. The numerical model resulted in a slightly different θ profile than that measured, where the largest differences occurred at the soil surface. Sensitivity and uncertainty analyses highlighted that a better precision is required when determining the soil hydraulic parameters. To improve the proposed method, the soil heat-vapor-water dynamics should be included and the assumption that the evaporation front remains at the soil surface must be relaxed. Additionally, if the AHFO calibration curve is enhanced, the errors of the estimated θ profile can be reduced and thus, successful estimation of the evaporation rates for a wider range of soil textures can be achieved. The spatial scales measured are an important advantage of the proposed method that should be further explored to improve the analysis presented here.


Asunto(s)
Agua Subterránea , Suelo , Calibración , Temperatura Ambiental , Agua
6.
Sheng Wu Gong Cheng Xue Bao ; 36(2): 276-286, 2020 Feb 25.
Artículo en Chino | MEDLINE | ID: mdl-32148000

RESUMEN

The aim of this study is to obtain bacterial perhydrolases with chlorination activity, expands the resources of perhydrolases, and lays a foundation for it's industrial applications. We constructed a metagenomic library using environmental DNA isolated from sludge samples of a paper mill of Tanghe county, and identified a per822 gene encoding a bacteria perhydrolase via activity-based functional screening. Then, we overexpressed Per822 heterologously in Escherichia coli, and characterized the recombinant enzyme after purification. Finally, we further investigated the ability of Per822 to produce peracetic acid (PAA). Sequence analysis revealed that per822 encoded a protein of 273 amino acids. The recombinant Per822 had the activity of peroxidase, esterase and halogenase respectively, and thus was regarded as a typical representative of multifunctional enzymes. The purified Per822 exhibited maximal chlorination activity (hyperhydrolysis) at 55 °C and pH 4.5 with monochlorodimedone as substrate, and the enzyme was stable in the pH range of 3.5-8.0 and below 70 °C. Also, the chlorination activity of this enzyme could be activated by Fe²âº. In addition, the enzyme displayed high ability to generate PAA using ethyl acetate as cosubstrate. The highly soluble expression, catalytic versatility and good PAA production capacity of Per822 make it a potential candidate in organic synthesis, wastewater treatment, disinfection and biomass pretreatment, etc.


Asunto(s)
Metagenoma , Secuencia de Aminoácidos , Clonación Molecular , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Temperatura Ambiental
7.
Waste Manag ; 105: 450-456, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-32135466

RESUMEN

The flue gas composition and the flue gas temperature at outlet of the economizer were tested, and the influence of flue gas recirculation (FGR) on the efficiency of the incinerator-waste heat boiler and NOx emission in a waste incineration power plant with a waste disposal capacity of 500 t/d was explored experimentally. The results indicate that the largest proportion of the total heat loss is the exhaust heat loss under different loads, and the next is the heat loss of slag. Within the test range, the efficiency of the incinerator-waste heat boiler increases from 80.26% to 80.42% as the ratio of the recirculating flue gas increases from 0 to 16.43%. The oxygen content in the flue gas and FGR have significant influence on NOx emissions. The NOx concentration at outlet of the economizer increases from 209.54 mg/m3 to 307.30 mg/m3, that is an increase of 46.65%, when the oxygen content at outlet of the economizer increases from 4.52% to 8.00%. Compared with the shutdown of FGR system, the NOx concentration at outlet of the economizer decreases from 209.54 mg/m3 to 126.15 mg/m3 when the FGR valve is fully opened. The results have important reference significance for the design of incinerator-waste heat boiler and the optimal operation of power plant.


Asunto(s)
Incineración , Eliminación de Residuos , Calor , Temperatura Ambiental
8.
Waste Manag ; 105: 457-466, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-32135467

RESUMEN

Biochar from agricultural biomasses and solid wastes represents a win-win solution for a rational waste management. Its sustainable usage requires the identification and standardization of biochar characteristics. The aim of this work was to identify the physical-chemical and spatial characteristics of biochars from pruning residues (PR), poultry litter (PL), and anaerobic cattle digestate (CD) at two pyrolysis temperatures (350 °C and 550 °C). The biochar characterization was carried out by applying emerging imaging techniques, 2D automated optical image analysis and hyperspectral enhanced dark-field microscopy (EDFM), and by SEM analysis. As predictable, the feedstock composition and the pyrolysis temperature strongly influence the physical structures of the biochar samples. Irrespective of charring temperature, PR biochar was mainly characterized by a broken and fragmented structure with an irregular and rough particle surface, completely different from the original PR wood cell. The EDFM imaging analysis evidenced the thermal degradation of PR vegetal products, composed primarily of hemicellulose, cellulose and lignin. On the contrary, small and regular particles with a smooth surface were produced by the PL pyrolysis, especially at 550 °C, due to the lower PL morphological homogeneity in comparison with the other biomasses. Finally, CD charring at both temperatures was characterized by changes in chemical composition, suggested by a lower pixel intensity. In conclusion, the emerging imaging techniques used in this study proved to be very effective in analyzing some properties of biochars, and can, therefore be considered as promising experimental strategies for detecting the feedstock and pyrolysis temperature of biochar.


Asunto(s)
Carbón Orgánico , Microscopía , Animales , Bovinos , Temperatura Ambiental , Madera
9.
Waste Manag ; 105: 560-565, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-32163835

RESUMEN

The paper examines the process of carbonization of waste from corncobs at carbonization temperatures within a range of 300-700 °C in a laboratory-scale reactor. These studies are important because of reductions in wood resources for the preparation of barbecue charcoal due to environmental protection laws and legislative processes in many countries aimed at the protection of forest resources. The results presented here include the physical and chemical properties of char as a function of carbonization temperatures as well as the characteristics of the heating rate of a fixed bed of corncobs and within a single corncob particle. The combustion characteristics of the char were determined using thermogravimetric analysis. The results show that the volatile matter yield of the char decreased, whereas the fixed carbon yield and higher heating value (HHV) increased, along with higher carbonization temperatures. TGA analysis shows that the ignition and burnout temperature of the char increased, with a simultaneous decrease in the value of the S index, along with increased carbonization temperatures. The results show that carbonization temperatures of 500 °C and above meet the standards for the production of barbecue charcoal.


Asunto(s)
Carbón Orgánico , Zea mays , Carbono , Temperatura Ambiental , Madera
10.
World J Microbiol Biotechnol ; 36(3): 51, 2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-32157408

RESUMEN

Culture-independent molecular-based approaches can be used to identify genes of interest from environmental sources that have desirable properties such as thermo activity. For this study, a putative thermo stable endoglucanase gene was identified from a mixed culture resulting from the inoculation of Brock-CMcellulose (1%) broth with mudspring water from Mt. Makiling, Laguna, Philippines that had been incubated at 90 °C. Genomic DNA was extracted from the cellulose-enriched mixed culture and endo1949 forward and reverse primers were used to amplify the endoglucanase gene, which was cloned into pCR-script plasmid vector. Blastn alignment of the sequenced insert revealed 99.69% similarity to the glycosyl hydrolase, sso1354 (CelA1; Q97YG7) from Saccharolobus solfataricus. The endoglucanase gene (GenBank accession number MK984682) was determined to be 1,021 nucleotide bases in length, corresponding to 333 amino acids with a molecular mass of ~ 37 kDa. The endoglucanase gene was inserted into a pET21 vector and transformed in E. coli BL21 for expression. Partially purified recombinant Mt. Makiling endoglucanase (MM-Engl) showed a specific activity of 187.61 U/mg and demonstrated heat stability up to 80 °C. The thermo-acid stable endoglucanase can be used in a supplementary hydrolysis step to further hydrolyze the lignocellulosic materials that were previously treated under high temperature-dilute acid conditions, thereby enhancing the release of more glucose sugars for bioethanol production.


Asunto(s)
Celulasa/genética , Celulasa/metabolismo , Celulosa/metabolismo , ADN , Genómica , Agua/metabolismo , Secuencia de Aminoácidos , Archaea/enzimología , Archaea/genética , Bacterias/enzimología , Bacterias/genética , Secuencia de Bases , Clonación Molecular , Estabilidad de Enzimas , Escherichia coli/genética , Concentración de Iones de Hidrógeno , Peso Molecular , Filipinas , Proteínas Recombinantes , Alineación de Secuencia , Sulfolobales/enzimología , Sulfolobales/genética , Temperatura Ambiental , Microbiología del Agua
11.
Acta Cir Bras ; 35(1): e202000101, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32159587

RESUMEN

Solid organ transplantation is a very complex process, in which the storage of the graft in a preservation solution is mandatory in order to extend ischemic times and contain further damage. The condition in which the organ is transplanted is critical for the outcome of the organ recipient. The recent emergence of generic versions of organ preservation solutions (solutions with the same composition and under the same legislation as the original versions, but with different brands) compelled us to study whether the standards are maintained when comparing the original and its generic counterpart. Along these lines, we discuss and comment on some aspects concerning this issue of general interest in the organ transplantation field.


Asunto(s)
Glutatión/química , Soluciones Preservantes de Órganos/química , Trasplante de Órganos/métodos , Calcio/análisis , Humanos , Soluciones Preservantes de Órganos/normas , Temperatura Ambiental , Factores de Tiempo
12.
Science ; 367(6484): 1301-1302, 2020 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-32193308
13.
Waste Manag ; 105: 566-574, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-32169812

RESUMEN

This work evaluates the potential of hydrothermal carbonization (HTC) to valorize the digestate derived from the anaerobic digestion of sewage sludge into useful materials for P and energy recovery. The hydrothermal treatment of digestate at 180-240 °C did not lead to high-rank hydrochars. On the other hand, inorganic P concentration did not change with the temperature, while as the carbonization temperature increased, the organic P retention yield in hydrochar became lower, increasing the total P in the process water obtained at the highest temperature, up to 25.3%. P recovery from acid leaching of the hydrochar obtained at 180 °C, via precipitation with CaO at pH up to 9, led to a brown solid precipitate with total P content close to 42 mg g-1, in the range of low grade phosphorus ores. Moreover, acid leaching reduced by 50% the ash content, yielding lignite-like upgraded hydrochars with higher heating values in the range of 20.5-23.1 MJ kg-1, fairly interesting as solid fuels. Anaerobic digestion of the process water enabled additional energy recovery in form of biogas (325 and 279 mL CH4 g-1 VS -at standard temperature and pressure; STP- from the process water resulting at 180 and 210 °C, respectively).


Asunto(s)
Carbono , Aguas del Alcantarillado , Biocombustibles , Fósforo , Temperatura Ambiental
14.
Water Res ; 174: 115634, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32113014

RESUMEN

Microplastics, as an emerging class of pollutants has become a global concern, and is receiving increasing attention. Interestingly, microplastics are always in their ageing process when they enter the real environment. Our study investigated the ageing properties of polystyrene (PS) plastics in air, pure water and seawater environments at 75 °C. A two-dimensional (2D) Fourier transform infrared (FTIR) correlation spectroscopy (COS) analysis was used to better understand the ageing mechanism of the PS plastics. Based on the 2D-COS analysis, different ageing mechanisms were identified under different ageing conditions, such as an ageing sequence of aged-PS particle functional groups in air: 1601(CC) > 1050(C-O)>1453(C-H)>1493(C-H)>1375(C-OH)>1666(CO). Among the functional group changes, O-functional groups (C-O, C-OH and CO) were introduced during the ageing process. Moreover, for pristine PS particles, hydrophobicity was a major factor for the interaction between the microplastics and organic pollutants. For aged-PS particles, their adsorption capacities were significantly enhanced as the degree of ageing increased. The ageing degree of PS was highly responsible for increasing of the specific surface area and the increase in oxygen-containing surface groups. Furthermore, there was a significant enhancement in the adsorption affinity for antibiotic contaminants than for polycyclic aromatic hydrocarbon contaminants. Aged PS particles had little adsorption of polycyclic aromatic hydrocarbons, because the presence of oxygen-containing surface groups on the aged PS plastics might allow the formation of hydrogen bonds with the surrounding water molecules. Overall, a 2D-COS analysis was an effective method for understanding the ageing process of microplastics under different environmental conditions at high temperature. These results also clearly demonstrated the characteristics and mechanisms of the interaction between aged-microplastics and organic pollutants, which could be useful for understanding the environmental behavior of co-existing pollutants.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Adsorción , Monitoreo del Ambiente , Plásticos , Temperatura Ambiental
15.
Bioresour Technol ; 304: 123017, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32087546

RESUMEN

In order to enhance the yield of high quality biodiesel form diseased swine fat, the ultrasound-assisted two-step catalyzed process was employed. First, three-dimensional ultrasound-assisted concentrated sulfuric acid pre-esterification experiment was carried out. Then, the transesterification reaction catalyzed by KOH was performed, and four parameters (catalyst concentration, reaction time, methanol/oil molar ratio and reaction temperature) were optimized using response surface methodology. The results showed that the optimal transesterification reaction conditions were catalyst concentration of 1.11 wt%, reaction temperature of 62.3 °C, methanol/oil molar ratio of 7.42:1, and reaction time of 116.14 min. The most significant factor affecting biodiesel purity was identified as catalyst concentration. Under the optimal conditions, the maximum biodiesel purity reached to 98% with the reaction time of 176.14 min, shortened by 63.3% compared with previous works. Furthermore, most of the biodiesel properties agreed the quality requirements established by Official Regulations of GB/25199-2017 of China.


Asunto(s)
Biocombustibles , Aceites Vegetales , Animales , Catálisis , China , Esterificación , Porcinos , Temperatura Ambiental
16.
Bioresour Technol ; 304: 122928, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32106020

RESUMEN

In order to explore changes in microbial enzyme activity and bacterial community, a 60-day composting experiment was conducted using cattle manure and straw under aeration rates of 0.45, 0.68, and 0.90 L min-1 kg-1 fresh weight. High aeration rate increased the cellulase, urease, alkaline and acid phosphatase activities, but decreased that of invertase and catalase. Cellulase, alkaline phosphatase and catalase were the main enzymes that affected the composting process. Microbial analysis showed that high aeration rate increased the uniformity of bacterial community in thermophilic phase, but decreased that in mature phase. Different aeration rate affected the bacterial community structure and further influenced the relationship between enzyme and functional bacteria. Regulating the temperature, moisture content and EC in specific phases to affect bacterial community succession could provide guidance for improving maturity of composting.


Asunto(s)
Celulasa , Compostaje , Animales , Bacterias , Bovinos , Estiércol , Suelo , Temperatura Ambiental
17.
Environ Monit Assess ; 192(3): 188, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-32076865

RESUMEN

This research investigated physical (temperature, salinity, and density) and chemical (dissolved oxygen, ammonium, nitrate, nitrite, phosphate, and silicate) properties of offshore seawater in the Red Sea northern Gulf of Aqaba; Jordanian Site were measured during 2013-2015 to assess the temporal and seasonal variation of the upper 400 m of the water column. The study also investigated seasonal variations, assessing the relationships of temperature with physical and chemical parameters. The average value of temperature for all data was 23.03 ± 1.58 °C. Temperature followed an expected seasonal cycle during 2013-2015, with well-mixed conditions in the upper 400 m of the water column during spring (Feb-Apr) and stratification during summer (Jul-Aug). There were no significant differences among years for temperature, but highly significant differences among months and depths. The average value of salinity (psu) for all data was 40.60 ± 0.10 with significant positive or negative differences among years, months, and depths. In general, dissolved oxygen, ammonium, nitrate, nitrite, and phosphate data showed positive or negative significant differences among months and depths with no significant annual variations. Silicate only showed significant differences among depths. Correlation tests between temperature and other parameters in the upper 25 m of the water column revealed significant inverse-relationships between temperature and all other parameters (other than salinity) that were attributed to the dominant thermal controls on seawater density, to the thermodynamic controls on oxygen solubility and to seasonal increases in light irradiance that allowed nutrient consumption by primary producers. In the intermediate water column (100-150 m), similar correlations were found as in the 0-25 m data, except for silicate. In the deeper waters (300-400 m), only salinity, density, and phosphate showed significant correlations with temperature, and indicated that the seasonal effects of primary production at depth were minimal. In general, the values of all parameters during the years 2013-2015 in the upper 400 m were comparable with previous studies (e.g., 1998-2003). In conclusion, this research manifested the strong correlation of temperature with some chemical parameters and presumed seasonal controls on primary production. Given the general lack of interannual variation, water quality in the northern Gulf of Aqaba appears relatively stable.


Asunto(s)
Monitoreo del Ambiente , Agua de Mar , Océano Índico , Salinidad , Estaciones del Año , Temperatura Ambiental
18.
J Environ Manage ; 261: 110112, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32001431

RESUMEN

The current energy demand and diminishing conventional fuels have forced researchers to find an alternative source of energy. Waste to energy is the current trend for converting waste materials (plastic waste) into valuable fuels. This article mainly discussed the detailed characterization of the pyrolytic products, their comparative analysis and the reaction mechanism at varying operating temperature. This article is a successor of part 1, which primarily focused on the characterization of different waste plastics, their TG analysis, the effect of reactor temperature on yield analysis in a batch reactor and their detailed degradation mechanism. Furthermore, the results presented in this article report the characterization of products at three processing temperatures of 450, 500 and 550 °C. The pyrolytic oils from all wastes excluding PS show a very low density ranging from 0.71 to 0.76 kg/m3, whereas PS pyrolytic density is reported between 0.86 and 0.88 kg/m3. The viscosity of oils increases with an increase in the processing temperature and is similar to the conventional fuels. The FTIR analysis of the products (oil & gases) obtained from HDPE, PP and mixed plastic waste (MIX) shows a large presence of alkanes and a higher presence of aromatics. PS analysis reported a large presence of aromatics (~75%). The GC-MS analysis of all pyrolytic oils from waste plastics, simulated wastes (virgin plastics) and distilled fraction of MIX pyrolysis oil is compared. The GC analysis of non-condensable gases at all processing temperature reports that MIX produce the maximum H2; HDPE, PS and MIX produces a high amounts of CH4 too. The formation of lower hydrocarbons (C5-C12) in pyrolysis oil shows a trend as MIX > PP > PS > HDPE, while for the heavier hydrocarbons (>C19) it is HDPE > PP > PS > MIX. The potential of the utilization of these products has been discussed in different sectors for future research.


Asunto(s)
Plásticos , Residuos , Hidrocarburos , Aceites , Temperatura Ambiental
19.
Ecol Lett ; 23(4): 701-710, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32052555

RESUMEN

Satellite data indicate significant advancement in alpine spring phenology over decades of climate warming, but corresponding field evidence is scarce. It is also unknown whether this advancement results from an earlier shift of phenological events, or enhancement of plant growth under unchanged phenological pattern. By analyzing a 35-year dataset of seasonal biomass dynamics of a Tibetan alpine grassland, we show that climate change promoted both earlier phenology and faster growth, without changing annual biomass production. Biomass production increased in spring due to a warming-induced earlier onset of plant growth, but decreased in autumn due mainly to increased water stress. Plants grew faster but the fast-growing period shortened during the mid-growing season. These findings provide the first in situ evidence of long-term changes in growth patterns in alpine grassland plant communities, and suggest that earlier phenology and faster growth will jointly contribute to plant growth in a warming climate.


Asunto(s)
Cambio Climático , Pradera , Biomasa , Ecosistema , Desarrollo de la Planta , Estaciones del Año , Temperatura Ambiental
20.
Phys Chem Chem Phys ; 22(6): 3734-3743, 2020 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-32010904

RESUMEN

The chaperonin system GroEL-GroES is present in all kingdoms of life and rescues proteins from improper folding and aggregation upon internal and external stress conditions, including high temperatures and pressures. Here, we set out to explore the thermo- and piezostability of GroEL, GroES and the GroEL-GroES complex in the presence of cosolvents, nucleotides and salts employing quantitative FTIR spectroscopy and small-angle X-ray scattering. Owing to its high biological relevance and lack of data, our focus was especially on the effect of pressure on the chaperonin system. The experimental results reveal that the GroEL-GroES complex is remarkably temperature stable with an unfolding temperature beyond 70 °C, which can still be slightly increased by compatible cosolutes like TMAO. Conversely, the pressure stability of GroEL and hence the GroEL-GroES complex is rather limited and much less than that of monomeric proteins. Whereas GroES is pressure stable up to ∼5 kbar, GroEl and the GroEl-GroES complex undergo minor structural changes already beyond 1 kbar, which can be attributed to a dissociation-induced conformational drift. Quite unexpectedly, no significant unfolding of GroEL is observed even up to 10 kbar, however, i.e., the subunits themselves are very pressure stable. As for the physiological relevance, the structural integrity of the chaperonin system is retained in a relatively narrow pressure range, from about 1 to 1000 bar, which is just the pressure range encountered by life on Earth.


Asunto(s)
Chaperonina 10/química , Chaperonina 60/química , Ambiente , Presión , Estabilidad Proteica , Temperatura Ambiental
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