A comparison between the mode of sction of organic matter and synthetic polymers in stabilizing soil crumbs

1956 ◽  
Vol 47 (3) ◽  
pp. 350-353 ◽  
Author(s):  
W. W. Emerson
Keyword(s):  
Organic Matter ◽  
Polyvinyl Alcohol ◽  
Natural Soil ◽  
Amino Groups ◽  
Ionic Polymer ◽  
Phosphate Ions ◽  
Before And After ◽  
The Stability ◽  
Method Of Extraction ◽  
Neutral Sodium

Synthetic soil crumbs stabilized by the addition of small quantities of a polymer, and natural soil crumbs from old grassland, have been extracted with neutral sodium pyrophosphate and alkali and the strengths of the crumbs compared before and after extraction, using the sodium saturation technique. Three polymers were used: polyvinyl alcohol (a non-ionic polymer), sodium alginate, and a vinyl acetate-maleic anhydride co-polymer (Vama), the latter both carboxylated polymers. Pyrophosphate was able to displace the carboxylated polymers from the synthetic crumbs, but not the stabilizing fraction of the organic matter from the grassland crumbs. 0·5N-NaOH produced a much greater reduction on the strength of the alginate treated crumbs compared with Vama crumbs, which is attributed to the weaker hydrogen bonds formed by the former. Prolonged leaching with alkali removed a considerable part of the stabilizing organic matter in the grassland crumbs. Neither method of extraction affected the stability of the polyvinyl alcohol crumbs.It is concluded that the grassland crumbs are stabilized by the formation of inter-lamellar complexes with the clay in the crumbs, and probably that the substance forming the complexes is a polymer and contains amino-groups.Evidence is also given that phosphate ions and the carboxylated polymers are attached in the same manner to the edges of the clay crystals.

scholarly journals Chemical Binding of Chitosan and Chitosan Nanoparticles onto Oxidized Cellulose

2015 ◽  
Vol 10 (2) ◽  
pp. 155892501501000 ◽  
Author(s):  
Olivera Sauperl ◽  
Mirjana Kostic ◽  
Jovana Milanovic ◽  
Lidija Fras Zemljic
Keyword(s):  
Chitosan Nanoparticles ◽  
Gravimetric Method ◽  
Fiber Surface ◽  
Oxidized Cellulose ◽  
Amino Groups ◽  
Before And After ◽  
The Difference ◽  
The Stability ◽  
Aldehyde Groups ◽  
The Masses

The aim of this study was to analyze binding of chitosan and chitosan nanoparticles onto cellulose via oxidized cellulose. The ability of chitosan and chitosan nanoparticles to be adsorbed onto surfaces was determined by the use of the XPS spectroscopy which provided information about chemical composition of the fiber surface. On the other hand, the gravimetric method was also used by which the amount of chitosan and chitosan nanoparticles bounded onto surface was calculated based on the difference in masses before and after functionalization. The most important was to study the influence of aldehyde groups on the stability of chitosan binding onto cellulose. Thus, desorption of chitosan/chitosan nanoparticles from the fiber surfaces was evaluated by the presence of total nitrogen (TN) in desorption bath as well as by polyelectrolyte titrations. Together with these two methods, desorption was evaluated also by gravimetric method, where the extent of desorption was evaluated on the basis of the differences in the masses of fibers before and after desorption. It is concluded that the chitosan and chitosan nanoparticles are more efficiently bounded onto oxidized cellulose in comparison with the non-oxidized (reference) ones. Despite the binding of the positively-charged amino groups with the negative groups of cellulose and consequently smaller amount of available/residual protonated amino groups that are responsible for bioactivity, such functionalized fibers are still specifically antimicrobial.

scholarly journals Influence of electrolytes and hydroxypropylsulfonation on paste stability of cassava starch/polyvinyl alcohol blend sizes for warp sizing

2020 ◽  
Vol 15 ◽  
pp. 155892501990066
Author(s):  
Wei Li ◽  
Lanjuan Wu ◽  
Zhengqiao Zhang ◽  
Yuhao Lu
Keyword(s):  
Polyvinyl Alcohol ◽  
Aqueous Medium ◽  
Sulfonic Acid ◽  
Cassava Starch ◽  
Degree Of Polymerization ◽  
Lower Degree ◽  
Weight Percentage ◽  
Separation Rate ◽  
Before And After ◽  
The Stability

The aim of this research was to ascertain the influences of electrolytes and hydroxypropylsulfonation on paste stabilities of cassava starch/polyvinyl alcohol blend sizes. The hydroxypropylsulfonated cassava starch was prepared via hydroxypropylsulfonation of hydrolyzed cassava starch with 3-chloro-2-hydroxypropyl sulfonic acid sodium in an aqueous medium. The stability was evaluated by measuring the initial demixing time. Before and after the addition of the electrolytes such as NaH2PO4, Na2SO4, and NaCl, the initial demixing time was 24, 20, 18, and 15 min for hydroxypropylsulfonated cassava starch/PVA1799 paste and 21, 17, 15, and 14 min for hydrolyzed cassava starch/PVA1799 one. This showed that the electrolytes accelerated the separation rates of hydroxypropylsulfonated cassava starch/polyvinyl alcohol blend pastes and hydrolyzed cassava starch/polyvinyl alcohol ones, thereby reducing the stability, and the acceleration followed the order: NaH2PO4 > Na2SO4 > NaCl. Increasing the concentration of electrolyte accelerated the separation rate and lowered the stability. The hydroxypropylsulfonation was able to reduce the separation rate and enhance paste stability. When the weight percentage of starch was fixed, with the rise in the degree of substitution from 0.011 to 0.029, the initial demixing time gradually increased, indicating the gradual decreases in the separation rates, thereby promoting the enhancement in the stability. Moreover, PVA0588 was lower than PVA1799 and PVA1788 in affecting the separation rate, which implied that polyvinyl alcohol with a lower degree of polymerization favored to promote the stability.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Sorbitol enhances the physicochemical stability of B12 vitamers

2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot
Keyword(s):  
Ascorbic Acid ◽  
Uv Light ◽  
Heat Exposure ◽  
Water Soluble ◽  
Uv Exposure ◽  
Physicochemical Stability ◽  
Before And After ◽  
The Stability

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

scholarly journals The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 779
Author(s):  
Václav Voltr ◽  
Ladislav Menšík ◽  
Lukáš Hlisnikovský ◽  
Martin Hruška ◽  
Eduard Pokorný ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Texture ◽  
Management Practices ◽  
Soil Depth ◽  
Operating Conditions ◽  
Hot Water ◽  
Natural Soil ◽  
Soil Productivity ◽  
Linear Regression Models

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security.

scholarly journals Investigation of Hydrothermally Stressed Silicone Rubber/Silica Micro and Nanocomposite for the Coating High Voltage Insulation Applications

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3567
Author(s):  
Faiza Faiza ◽  
Abraiz Khattak ◽  
Safi Ullah Butt ◽  
Kashif Imran ◽  
Abasin Ulasyar ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Structural Changes ◽  
Polymer Chains ◽  
Hydrothermal Conditions ◽  
Silica Filler ◽  
Before And After ◽  
Aging Conditions ◽  
The Stability ◽  
Micro Silica ◽  
Applied Stresses

Silicone rubber is a promising insulating material that has been performing well for different insulating and dielectric applications. However, in outdoor applications, environmental stresses cause structural and surface degradations that diminish its insulating properties. This effect of degradation can be reduced with the addition of a suitable filler to the polymer chains. For the investigation of structural changes and hydrophobicity four different systems were fabricated, including neat silicone rubber, a micro composite (with 15% micro-silica filler), and nanocomposites (with 2.5% and 5% nanosilica filler) by subjecting them to various hydrothermal conditions. In general, remarkable results were obtained by the addition of fillers. However, nanocomposites showed the best resistance against the applied stresses. In comparison to neat silicone rubber, the stability of the structure and hydrophobic behavior was better for micro-silica, which was further enhanced in the case of nanocomposites. The inclusion of 5% nanosilica showed the best results before and after applying aging conditions.

Environmental relevance of adsorption of doxycycline, enrofloxacin, and sulfamethoxypyridazine before and after the removal of organic matter from soils

2021 ◽  
Vol 287 ◽  
pp. 112354
Author(s):  
C. Alvarez-Esmorís ◽  
M. Conde-Cid ◽  
M.J. Fernández-Sanjurjo ◽  
A. Núñez-Delgado ◽  
E. Álvarez-Rodríguez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Before And After ◽  
Environmental Relevance

Influence of Salts and Natural Organic Matter on the Stability of Bacteriophage MS2

Langmuir ◽  
2010 ◽  
Vol 26 (2) ◽  
pp. 1035-1042 ◽  
Author(s):  
Steven E. Mylon ◽  
Claudia I. Rinciog ◽  
Nathan Schmidt ◽  
Leonardo Gutierrez ◽  
Gerard C. L. Wong ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Bacteriophage Ms2 ◽  
The Stability

Study on Mechanism of Removing the Organic Matter in Heavy Oil Sewage by the Electric Flocculation Method

2012 ◽  
Vol 535-537 ◽  
pp. 2201-2208
Author(s):  
Yong Wang ◽  
Jie Nian Jie ◽  
Zhi Yong Li ◽  
Li Guo Wang ◽  
Jiang Wu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Heavy Oil ◽  
Tin Dioxide ◽  
Electrochemical Treatment ◽  
Oily Wastewater ◽  
Treatment Technology ◽  
Before And After ◽  
Treatment Technologies ◽  
Oily Wastewater Treatment

Oily sewage is one of the wastes produced in the oil industry production process and its quantity has been increasing year by year, which influences the environment and human health severely. Electric flocculation method is one of the wide application electrochemical treatment technologies for the oily wastewater treatment at home and abroad, which has higher efficiency than other technologies at the aspect of the organic pollutants degradation. A simulative experiment device dealing with heavy oil sewage by the electric flocculation method has been designed in this paper. The mechanism of the electric flocculation method in removing organic matter of the heavy oil sewage by analyzing the change of the composition and content of the organic matter in water samples before and after the process of the electric flocculation has been studied. Research results show: the carbon/tin dioxide electrode is better than the carbon/ ruthenium dioxide electrode in removing organic matter; most alkanes matters in the oily wastewater have been removed in the dispersing oil form by the electric flocculation; as the current density increases, the types and quantity of the response organic matter can be improved while types of the new synthetic organics increase. At the same time, this paper provides a theory support in specific optimization of the electricity flocculation flotation in oily wastewater treatment technology and process.

scholarly journals Stability of Fe-oxide nanoparticles coated with natural organic matter under relevant environmental conditions

2014 ◽  
Vol 70 (12) ◽  
pp. 2040-2046 ◽  
Author(s):  
L. Chekli ◽  
S. Phuntsho ◽  
L. D. Tijing ◽  
J. L. Zhou ◽  
J.-H. Kim ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Environmental Conditions ◽  
Divalent Cations ◽  
Oxide Nanoparticles ◽  
Fe Oxide ◽  
Coated Nanoparticles ◽  
Aggregation Behaviour ◽  
Physico Chemical ◽  
The Stability

Manufactured nanoparticles (MNPs) are increasingly released into the environment and thus research on their fate and behaviour in complex environmental samples is urgently needed. The fate of MNPs in the aquatic environment will mainly depend on the physico-chemical characteristics of the medium. The presence and concentration of natural organic matter (NOM) will play a significant role on the stability of MNPs by either decreasing or exacerbating the aggregation phenomenon. In this study, we firstly investigated the effect of NOM concentration on the aggregation behaviour of manufactured Fe-oxide nanoparticles. Then, the stability of the coated nanoparticles was assessed under relevant environmental conditions. Flow field-flow fractionation, an emerging method which is gaining popularity in the field of nanotechnology, has been employed and results have been compared to another size-measurement technique to provide increased confidence in the outcomes. Results showed enhanced stability when the nanoparticles are coated with NOM, which was due to electrosteric stabilisation. However, the presence of divalent cations, even at low concentration (i.e. less than 1 mM) was found to induce aggregation of NOM-coated nanoparticles via bridging mechanisms between NOM and Ca2+.

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