The reliability of radiocarbon dates of different carbon fractions in the Australian tropical savannas: A case study from Sanamere Lagoon, northeast Australia

Author(s):  
Maria Rivera-Araya ◽  
Michael Bird ◽  
Cassandra Rowe ◽  
Sean Ulm ◽  
Vladimir Levchenko

<p>The selection and pre-treatment of a reliable organic fraction from which to acquire radiocarbon dates is fundamental to obtain accurate chronologies. Sampling from tropical lakes is particularly challenging given the adverse preservation conditions and diagenesis in these environments. Our research is the first to examine and quantify the differences between the radiocarbon date results from different carbon fractions and pretreatments from the same depths from a tropical lake sediment core (1.72 m long) located in north Australia to assess which one(s) are more reliable. Six different organic fractions (bulk organics, pollen concentrate, cellulose, stable polycyclic aromatic carbon (SPAC), charcoal >250 um and charcoal >63 um), for a total of 27 radiocarbon dates, were compared in six different depths along the core. Acid-base-acid (ABA), modified ABA (30 % hydrogen peroxide + ABA), 2chlorOx (a novel cellulose pre-treatment method) and hydrogen pyrolysis (hypy) were used to pre-treat the correspondent organic fractions. The oldest date is 31,295 calibrated years before present (cal yr BP) and the youngest is 2,048 cal yr BP, spanning 29,247 years. The smallest offset between the minimum and the maximum age in a given depth was found to be 975 years (between SPAC and charcoal >63 um) and the largest 16,527 years (between pollen concentrate and SPAC). The SPAC fractions pre-treated with hypy consistently yielded older ages compared to all other fraction in most cases, while bulk organics yielded consistently younger ones. The magnitude and consistency of the offsets and the physical and chemical properties of the tested organic fractions suggest that SPAC is the most reliable fraction to date in tropical lake sediments and that hypy successfully removes contamination sourced from exogenous carbon.</p>

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 660
Author(s):  
Qingqing Liu ◽  
Di Gao ◽  
Wei Xu

According to the old surface coating process of European and American furniture, the surface of modified poplar is first differentiated pre-treatment, and then the bottom color modification and material color modification are respectively applied to the modified poplar after the surface differentiation treatment. The visual physical quantity and physical and chemical properties were measured and compared with mahogany, which is commonly used in old furniture in Europe and America to explore the effect of colorants and coloring steps, as well as different surface pretreatments on the coloring effect. Finally, it is concluded that continuous coloring operations can narrow the difference in brightness and red color value in the coloring layer of modified poplar and mahogany. Continuous coloring operations increase the difference between the yellow-green color values of modified poplar and mahogany. Therefore, the coloring difference between modified poplar and mahogany was affected by the colorant and coloring steps. Through color accumulation, the gap between the two in the target color coloring effect can be reduced, thereby reducing the difference between the coloring effect of modified poplar and mahogany.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan José Martínez-Nicolás ◽  
Pilar Legua ◽  
Dámaris Núñez-Gómez ◽  
Rafael Martínez-Font ◽  
Francisca Hernández ◽  
...  

AbstractFor the maintenance of the economic activity of the ports, it is necessary to dredge the marine sediments in order to guarantee their depth. These sediments, considered by European legislation as residues, present relevant limitations of use and generate environmental and economic problems concerning their final disposal. In this context, the present work aims to identify the phytoremediated dredged sediments potential as an alternative to the traditional substrate (peat) in horticultural growing through two-years controlled strawberry cultivation. The growing media mixes used were: (1) 100% peat (Pt) as a control substrate; (2) 100% dredged remediated sediment (DRS); (3) 50% each (Pt-DRS). The dredged sediment, plant drainage and strawberry plant parts (leaves, stems, roots, and fruits) were analyzed to mineral elements, heavy metal contents, and pesticide residues (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and specific fumigants) during the experimental period. Only seven (Mn, Fe, Zn, Mo, Al, Mn and Ni) of the twenty-two metals and two (nitrates and fluorene) of the six hundred-thirteen pesticides analyzed were detected in the strawberry fruits. In all the cases, values detected were under the Spanish and European legal limit. The suitability of strawberry fruits for fresh and/or processed consumption with no risk was confirmed. Based on the results, can be affirmed that the dredged remediated sediment can be used as a culture substrate, alone or mixed with other substrates. Additional researches should be carried out to confirm the sediment characteristics and compare with other substrates to improve the physical and chemical properties.


Author(s):  
Meysam Madadi ◽  
Yuanyuan Tu ◽  
Aqleem Abbas

Lignocellulosic materials among the alternative energy resources are the most desirable resources that can be employed to produce cellulosic ethanol, but this materials due to physical and chemical structure arranges strong native recalcitrance and results in low yield of ethanol. Then, a proper pre-treatment method is required to overcome this challenge. Until now, different pre-treatment technologies have been established to enhance lignocellulosic digestibility. This paper widely describes the structure of lignocellulosic biomass and effective parameters in pre-treatment of lignocelluloses, such as cellulose crystallinity, accessible surface area, and protection by lignin and hemicellulose. In addition, an overview about the most important pre-treatment processes include physical, chemical, and biological are provided. Finally, we described about the inhibitors enzymes which produced from sugar degradation during pre-treatment process and the ways to control this inhibitors.Int. J. Appl. Sci. Biotechnol. Vol 5(1): 1-11


Soil Research ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 807
Author(s):  
Lea Piscitelli ◽  
Anna Daniela Malerba ◽  
Giuseppe Natale Mezzapesa ◽  
Stefano Dumontet ◽  
Donato Mondelli ◽  
...  

Polycyclic aromatic hydrocarbons (PAHs) are a large group of compounds composed of two or more aromatic rings. They are extremely toxic pollutants largely produced by anthropogenic activities and characterised by high persistence in the environment. Soils contaminated by PAHs could be depolluted by bioremediation techniques, an effective in-situ procedure which provides the addition of exogenous substrates able to sustain and enhance the autochthonous soil microflora and the allochthon microbial inoculum. Our research aims to study the effects of biochar, produced by slow pyrolysis of olive pomace, as a bio-stimulant of soil microflora or support for the colonisation of the allochthon Trichoderma harzianum, on degradation of pyrene used here as model molecule for the PAH family. Biochar is considered an excellent soil conditioner because of its positive effect on soil physical and chemical properties and its positive interaction with soil microorganisms. Autochthonous microbial growth, T. harzianum growth and microbial pyrene-degradation activity were surveyed in soil samples spiked with 50 ppm of pyrene and incubated for up to 28 days. Pyrene concentration was reduced by ~70% in 28 days in both bioaugmentation and biostimulation tests. Olive mill pomace biochar did not interfere with pyrene bioavailability and did not affect microbial pyrene-degrading activity. The T. harzianum did not display a distinctive ability in degrading pyrene and partially inhibited the endogenous soil microflora.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1951
Author(s):  
YuLing Yang ◽  
Ke Lin ◽  
Li Yang

Photodynamic therapy (PDT) is a promising anticancer noninvasive method and has great potential for clinical applications. Unfortunately, PDT still has many limitations, such as metastatic tumor at unknown sites, inadequate light delivery and a lack of sufficient oxygen. Recent studies have demonstrated that photodynamic therapy in combination with other therapies can enhance anticancer effects. The development of new nanomaterials provides a platform for the codelivery of two or more therapeutic drugs, which is a promising cancer treatment method. The use of multifunctional nanocarriers for the codelivery of two or more drugs can improve physical and chemical properties, increase tumor site aggregation, and enhance the antitumor effect through synergistic actions, which is worthy of further study. This review focuses on the latest research progress on the synergistic enhancement of PDT by simultaneous multidrug administration using codelivery nanocarriers. We introduce the design of codelivery nanocarriers and discuss the mechanism of PDT combined with other antitumor methods. The combination of PDT and chemotherapy, gene therapy, immunotherapy, photothermal therapy, hyperthermia, radiotherapy, sonodynamic therapy and even multidrug therapy are discussed to provide a comprehensive understanding.


Author(s):  
Ivan Milovanovic ◽  
Maria Hayes

In recent years, demand for consumption of marine foods, and especially fish, has substantially increased worldwide. The majority of collagen available is sourced from mammalian-derived products. Although fish derived gelatine is a viable alternative to mammalian sourced gelatine, there are some challenges related to the use of fish gelatine including odour, colour, gelling and film forming properties as well as consistency in gelatine amino acid composition. Chemicals used for pre-treatment, as well as extraction conditions such as temperature and time, can influence the length of polypeptide chains that result and the functional properties of the gelatine. Compared to mammalian sources, gelatines derived from fish show notable differences in physical and chemical properties, and great care should be paid to optimization of the production process in order to obtain a product with the best properties for intended applications. The focus of this review is to explore the feasibility of producing gelatine sourced from marine processing by-products using different pre-treatment and extraction strategies with the aim of improving the techno-functional properties of the final product and improving the clean-label status of gelatines. The bioactivities of gelatine hydrolysates are also discussed.


2017 ◽  
Vol 751 ◽  
pp. 773-778
Author(s):  
Napatsawan Saengarunthong ◽  
Parinya Khongthong ◽  
Gasidit Panomsuwan ◽  
Tomonaga Ueno ◽  
Nagahiro Saito ◽  
...  

Carbon nanoparticles (CNPs) were successfully synthesized from the mixture of used motor oil and benzene via a solution plasma process (SPP). The synthesis was achieved within a single step at room temperature and atmospheric pressure. The effects of mixing ratio between used motor oil and benzene on the physical and chemical properties of CNPs were investigated by means of field-emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Raman spectroscopy. The results revealed that there were no significant changes in morphological feature and chemical functional groups on CNPs at different mixing ratios. The CNPs exhibited the aggregates of fine particles with the diameter of about 20–30 nm. The crystallinity of CNPs was found to be slightly increase when synthesized under the presence of used motor oil, possibly due to the effect of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in used motor oil. We expect that the conversion of used motor oil into CNPs by SPP could be another attractive way to add the value to used motor oil prior to disposing.


2021 ◽  
Vol 22 (1) ◽  
pp. 399
Author(s):  
Yale Yue ◽  
Xiao Zhao

Photothermal therapy (PTT) mediated by nanomaterial has become an attractive tumor treatment method due to its obvious advantages. Among various nanomaterials, melanin-like nanoparticles with nature biocompatibility and photothermal conversion properties have attracted more and more attention. Melanin is a natural biological macromolecule widely distributed in the body and displays many fascinating physicochemical properties such as excellent biocompatibility and prominent photothermal conversion ability. Due to the similar properties, Melanin-like nanoparticles have been extensively studied and become promising candidates for clinical application. In this review, we give a comprehensive introduction to the recent advancements of melanin-like nanoparticles in the field of photothermal therapy in the past decade. In this review, the synthesis pathway, internal mechanism and basic physical and chemical properties of melanin-like nanomaterials are systematically classified and evaluated. It also summarizes the application of melanin-like nanoparticles in bioimaging and tumor photothermal therapy (PTT)in detail and discussed the challenges they faced in clinical translation rationally. Overall, melanin-like nanoparticles still have significant room for development in the field of biomedicine and are expected to applied in clinical PTT in the future.


Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 804 ◽  
Author(s):  
Ruixiang Li ◽  
Tian Li ◽  
Qixing Zhou

A high-efficiency method to deal with pollutants must be found because environmental problems are becoming more serious. Photocatalytic oxidation technology as the environmentally-friendly treatment method can completely oxidate organic pollutants into pollution-free small-molecule inorganic substances without causing secondary pollution. As a widely used photocatalyst, titanium dioxide (TiO2) can greatly improve the degradation efficiency of pollutants, but several problems are noted in its practical application. TiO2 modified by different materials has received extensive attention in the field of photocatalysis because of its excellent physical and chemical properties compared with pure TiO2. In this review, we discuss the use of different materials for TiO2 modification, highlighting recent developments in the synthesis and application of TiO2 composites using different materials. Materials discussed in the article can be divided into nonmetallic and metallic. Mechanisms of how to improve catalytic performance of TiO2 after modification are discussed, and the future development of modified TiO2 is prospected.


2013 ◽  
Vol 699 ◽  
pp. 470-475
Author(s):  
Qiu Ru Wang ◽  
Ji Chuan Huo ◽  
Yong Lin Lei ◽  
Wei Ai

With excellent physical and chemical properties, aluminum phosphate is a great potential high temperature protective coating of fiber. In this paper, a kind of aluminum phosphate low in acidity was prepared from aluminum isopropoxide (AIP) and diammonium phosphate ((NH4)2HPO4) by hydrothermal and liquid-phase reaction methods respectively. The performance of aluminum phosphate prepared by the two methods was comparatively evaluated using FTIR, XRD, TG techniques. As a protective coating, aluminum phosphate was applied to the pre-treatment of high silica reinforced fiber cloth. After added 1% MgO, The SEM images indicated that aluminum phosphate prepared by hydrothermal method could cover the surface of the fiber more uniformly. The mechanical testing results showed that tensile strength of the obtained coated material was improved at high temperature.


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