Integration of Stalk Destruction Methods for the Glyphosate Herbicide-Resistant Cotton

The increase in geographical areas used for cultivation of transgenic glyphosate herbicide-resistant cotton has hindered the stalk destruction, compromised the phytosanitary break implementation and consequently increased the population of insect pests and cotton plant pathogens. This study evaluated the efficiency of the combining mechanical and chemical methods in the destruction of transgenic cotton stalk resistant to the glyphosate herbicide. Two experiments were carried out in 2015 and 2016 in Primavera do Leste,-Mato Grosso, Brazil and Luís Eduardo Magalhães, Bahia, Brazil, respectively. The study evaluated different mechanical destruction equipment in combination with the chemical methods. In each environment, a randomized block experiment with four replications was employed. The results of the experiments indicated that the mechanical destruction increased the control efficiency by at least 10% when compared to chemical destruction of the cotton stalk. Chemical destruction with herbicides combined with mechanical destruction methods does not increase the control efficiency of cotton stalks destruction. Furthermore, the application of hormonal herbicides following the mechanical shredding of cotton stalks does not increase the control efficiency of glyphosate-resistant cotton stalk.

Antarctic ozone recovery

Since 1976, and more so since 1985, the Antarctic ozone level has suffered considerable depletion (termed as Antarctic ozone hole), attributed to the destructive effects of CFC compounds leaking into the atmosphere from man-made gadgets. The 12-month running means of South Pole Dobson ozone (monthly means, upto 1999 end only) were subjected to spectral analysis, which showed considerable, significant amplitudes for QBO (Quasi-biennial, 2-3 years) and QTO (Quasi-triennial, 3-4 years) oscillations, with a total range of 20-30 DU. When subtracted from the original values, a fairly smooth variation was seen, with a decrease from ~260 DU in 1986 to ~230 DU in 1996 (~12% decrease in 12-month running means), and an almost steady level thereafter. Thus, the net ozone variation at South Pole consists of two parts, (i) a long-term monotonically downward trend upto 1996 and a steady level thereafter and (ii) a superposed QBO-QTO oscillation. The chemical destruction effect is not likely to disappear soon, and may even increase if greenhouse effects, major volcanic eruptions or enhanced stratospheric cooling intervene. If the long-term level (i) remains steady, an extrapolation of the QBO-QTO patterns indicates that the ozone level is due for an increase from about 1999 end to about 2001 beginning. The purpose of the present analysis is to point out that, if such an increase of 20-30 DU occurs, it should not be misinterpreted as due to a decrease in chemical destruction, which scientists are eagerly awaiting due to the indication of a reduction in the halogen load in recent years due to adherence to the Montreal Protocol. After one or two years (in 2002), the extrapolated QBO-QTO oscillation may bring down the ozone level back again to the 1999 end level, and the apparent recovery may turn out to be a false signal.

Chemical and enzymatic destruction of chondroitin sulfate from Arctic skate

Due to its biocompatibility with human and animal tissues, low toxicity, and biodegradability, chondroitin sulfate (CS) is of great interest for medicine. Since CS is used as a pharmaceutical preparation, its molecular weight and solubility determine the possibilities of its use. This work presents the results of studying the chemical and enzymatic destruction of CS macromolecules and its effect on the molecular weight, solubility and crystallinity degree of the polysaccharide. CS was obtained from the cartilaginous tissue of the Arctic skate ( Amblyraja hyperborea ). At the stage of cartilage tissue fermentolysis, the enzymes pancreatin, hepatopancreatin and protosubtil were used. The obtained CS samples were identified by IR spectroscopy. Enzymatic destruction of glycosidic bonds in cholesterol macromolecules was carried out with a 1 % solution of the enzyme hepatopancreatin, chemical destruction with hydrogen peroxide and hydrochloric acid. The CS content in the samples was determined by the Dische method. The chemical composition of CS samples was evaluated by standard methods. The average molecular weight (MW) was determined using high performance liquid chromatography and the nephelometric method. The crystallinity degree (CD) was determined by graphical processing of diffraction patterns obtained by X-ray phase analysis of CS samples. It was found that under the action of hepatopancreatin and hydrogen peroxide, deep destruction of chondroitin sulfate occurs, to the formation of low molecular weight and oligomeric fragments. Under conditions of acid destruction in 0.5 N HCl for 20 min the MW of chondroitin sulfate is reduced by 10 % compared to the initial one. Acid destruction causes a significant decrease in the CD of the CS samples. For CS samples not degraded in acid, the solubility in distilled water increases with decreasing MW and CD. The solubility of CS after acid destruction in the range of pH = 5-9 units is 99.0 ± 0.5 %. This high solubility is most likely explained by the significant content of the amorphous phase in the samples.

Chemical recycling of polyethyleneterephthalate as a method for obtaining effective modifiers of polymer materials

The article provides a brief overview of the research carried out at the Department of Chemical Technology of Polymers of SPSIT in the field of chemical destruction of household waste of polyethyleneterephthalate from 2008 to the present. It has been shown that the use of PET glycolysis and aminolysis methods makes it possible to obtain useful products that can be used both as independent binders (unsaturated polyester resins) and as effective modifiers that increase the physical, mechanical and operational properties of already well-proven polymer materials. In some cases, modification of the compositions with PET chemical recycling products leads to an increase in the characteristics of polymer materials by up to 5 times.

The Technology of Precision-selective Electrostatic Separation of Mixed Secondary Polymers

This technology of precision-selective electrostatic separation of mixed secondary polymers with pre-activation of their surfaces with surfactants for chemical destruction of surface polymer is described. A prototype of the process of precision selective separation of mixed polymer materials in the electrostatic field has been developed. Optimum operating modes of the process of activation of polymer surfaces with surfactant solutions as a preliminary stage of separation of mixed polymers in the electrostatic field are determined. An experimental prototype of a process line has been created for selective electrostatic separation chemically activated narrow-fractional mixed crushed polymer waste.

Change in the Structure of Asphaltene Macromolecules of the Krapivinskoye Oil Field During Biological Oxidation

Using physico-chemical methods of research (elemental analysis, infrared spectroscopy, selective chemical destruction of sulfide and ester bonds, chromatomass spectrometry) the influence of biodegradation processes on the composition and structure of asphaltenes of light oil at the Krapivinskoye deposit was studied. The results of comparative characteristics of initial asphaltenes and asphaltenes after biodestruction are presented. Attention is paid to studying their structural parameters and composition of fragments bound in asphaltene molecules through ester and sulfide bridges. It has been shown that microbial oxidation of asphaltenes of light oil by aboriginal soil microflora (laboratory experiment) occurs through a series of catalytic processes with formation of intermediate products of transformation – alcohols, aldehydes, ketones and fatty acids. It has been established that “grey and ether-bound” fragments in asphaltene molecules of biodegradable oil differ from “bound” compounds in the structure of the original asphaltenes with the qualitative composition of saturated and aromatic hydrocarbons and heteroatomic components

Regional characteristics of atmospheric sulfate formation in East Antarctica imprinted on 17O-excess signature

<p><sup>17</sup>O-excess (<em>Δ</em><sup>17</sup>O = <em>δ</em><sup>17</sup>O − 0.52 × <em>δ</em><sup>18</sup>O) of sulfate trapped in Antarctic ice cores has been proposed as a potential tool for assessing past oxidant chemistry, while insufficient understanding of atmospheric sulfate formation around Antarctica hampers its interpretation. To probe influences of regional specific chemistry, we compared year-round observations of <em>Δ</em><sup>17</sup>O of non-sea-salt sulfate in aerosols (<em>Δ</em><sup>17</sup>O(SO<sub>4</sub><sup>2−</sup>)<sub>nss</sub>) at Dome C and Dumont d’Urville, inland and coastal sites in East Antarctica, throughout the year 2011. Although <em>Δ</em><sup>17</sup>O(SO<sub>4</sub><sup>2–</sup>)<sub>nss</sub> at both sites showed consistent seasonality with summer minima (~1.0 ‰) and winter maxima (~2.5 ‰) owing to sunlight-driven changes in the relative importance of O<sub>3</sub>-oxidation to OH- and H<sub>2</sub>O<sub>2</sub>-oxidation, significant inter-site differences were observed in austral spring–summer and autumn. The co-occurrence of higher <em>Δ</em><sup>17</sup>O(SO<sub>4</sub><sup>2–</sup>)<sub>nss</sub> at inland (2.0 ± 0.1 ‰) than the coastal site (1.2 ± 0.1 ‰) and chemical destruction of methanesulfonate (MS<sup>–</sup>) in aerosols at inland during spring–summer (October to December), combined with the first estimated <em>Δ</em><sup>17</sup>O(MS<sup>–</sup>) of ~16 ‰, implies that MS<sup>–</sup> destruction produces sulfate with high <em>Δ</em><sup>17</sup>O(SO<sub>4</sub><sup>2–</sup>)<sub>nss</sub> of ~12 ‰. If contributing to the known post-depositional decrease of MS<sup>–</sup> in snow, this process should also cause a significant post-depositional increase in <em>Δ</em><sup>17</sup>O(SO<sub>4</sub><sup>2–</sup>)<sub>nss</sub> over 1 ‰, that can reconcile the discrepancy between <em>Δ</em><sup>17</sup>O(SO<sub>4</sub><sup>2–</sup>)<sub>nss</sub> in the atmosphere and ice.</p>

CHEMICAL CORROSION PROCESSES OCCURRING IN THE MATERIAL OF LARGE-BLOCK POROUS CERAMICS

Large-block porous ceramics, which enter the market of building materials, have a number of undeniable qualities: low thermal conductivity, low density, high aesthetic qualities. According to its design features, this material is a modern prototype of hollow bricks used in construction since the nineteenth century. Field studies of the work of enclosing structures using hollow bricks have shown that in many cases, the bricks laid in the enclosing structures of buildings 60-80 years ago were significantly destroyed. In this case, the destruction mechanism does not depend on the polythermal load on the material. The hypothesis that the destruction is associated with the chemical destruction of the material was investigated using the developed method for determining the chemical resistance of the material of wall ceramics. The conducted studies confirmed the hypothesis. Studies of the chemical resistance of the material of large-block porous ceramics should be taken into account in the production technology of ceramics.

Prospects of the nasal spray in first aid tools for acute poisoning

The purpose of this review is to substantiate approaches for improving first aid in acute poisoning. Early administration of medical agents to the victims is advisable, but in injectable dosage form is problematic. An alternative is a nasal spray – dosage form that is suitable for systemic administration of pharmaceutical substances with small molecular weight (up to 1000 Da) and moderate hydrophilicity (log Poctanol/water ≥ 0), and a single dose of which can be contained in volume of up to 0, 3 ml. These criteria are met by the number of pharmaceutical substances used for the treatment of acute poisoning with substances that can form foci of mass destruction. This defines the perspective of nasal sprays as a medical device that allows to speed up, simplify and make it safer to use drugs when providing first aid in the centers of mass chemical destruction.

The NASA Atmospheric Tomography Mission: A Global-Scale Survey of Composition, Reactivity, and Transport in the Remote Atmosphere

<p>     The last seventy years have witnessed a marked acceleration of the impact of human activity impacting the planet due to the combination of rapid population growth, increased consumption of resources, and technological development. Nearly the entire human population occupies an astonishingly small percentage of the Earth’s surface, yet the imprint of human activity is being recorded in global climate and is perturbing the chemistry and composition of the most remote stretches of the atmosphere. These remote regions are exceptionally important for global air quality and climate (accounting on average for 75% of global CH<sub>4</sub> removal, 59% of chemical production of O<sub>3</sub>, and 68% of chemical destruction of O<sub>3</sub>), yet the paucity of observations over the remote oceans have limited our understanding of these fundamental processes and their sensitivity to increased human perturbation.</p><p>     The NASA Atmospheric Tomography Mission (ATom) was designed to address these gaps in our understanding of chemical composition, reactivity, and transport through a combination of extensive measurements and photochemical modeling, and to provide much needed observational data from the remote regions of the atmosphere to provide rigorous tests that will lead to improvements in our global chemistry-climate models and to validate remote sensing retrievals. From 2016-2018, ATom utilized the fully instrumented NASA DC-8 research aircraft to collect an unprecedented suite of measurements of trace gases, aerosols, and key radical species from the remote troposphere and lower stratosphere.  Four complete pole-to-pole global circuits (one in each season) were conducted by performing near-continuous vertical profiles between 0.2 – 14 km altitude along meridional transects of the Pacific and Atlantic Ocean Basins. The data provided by this project have already led to several significant new findings, with many more on the horizon as research teams continue to uncover the full value of this dataset. In this talk, we will provide an overview of the ATom mission and discuss some of the major outcomes and new findings that have resulted from this project to date.</p>