scholarly journals Formulation and Study of an Environmentally Friendly Microemulsion-Based Drilling Fluid (O/W) with Pine Oil

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7981
Author(s):  
Roxana P. F. de Sousa ◽  
Glauco S. Braga ◽  
Raphael R. da Silva ◽  
Giovanna L. R. Leal ◽  
Júlio C. O. Freitas ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Chemical Properties ◽  
Tween 80 ◽  
High Water ◽  
High Water Content ◽  
Fluid Loss ◽  
Pine Oil ◽  
Wide Range ◽  
Solids Content ◽  
Biodegradable Surfactant

This work has developed and evaluated a microemulsion-based drilling fluid formulation with characteristics to be applied in oil wells. The microemulsion was formulated with a solution of water/glycerol, pine oil, and Tween 80, a nonionic and biodegradable surfactant. The physical and chemical properties of the drilling fluid obtained in this work were investigated through rheology and filtration analysis, solids content, aging, lubricity, toxicity, and thermal degradation. A non-toxic microemulsion-based drilling fluid oil-in-water (O/W) with high lubricity (0.07638) and thermal stability was obtained with suitable viscosity, gel strength and low fluid loss (4.0 mL), low solids content (6%), stability in a wide range of salinity conditions, and the possibility of high water content (above 85% in mass fraction). The fluid presented a pseudoplastic behavior, and statistically significant Herschel–Bulkley parameters were obtained.

scholarly journals Interactions among temperature, moisture, and oxygen concentrations in controlling decomposition rates in a boreal forest soil

2017 ◽  
Vol 14 (3) ◽  
pp. 703-710 ◽  
Author(s):  
Carlos A. Sierra ◽  
Saadatullah Malghani ◽  
Henry W. Loescher
Keyword(s):  
Boreal Forest ◽  
High Temperatures ◽  
High Water ◽  
High Water Content ◽  
Organic Soils ◽  
Soil Core ◽  
Decomposition Rates ◽  
Environmental Controls ◽  
Wide Range ◽  
Oxygen Concentrations

Abstract. Determining environmental controls on soil organic matter decomposition is of importance for developing models that predict the effects of environmental change on global soil carbon stocks. There is uncertainty about the environmental controls on decomposition rates at temperature and moisture extremes, particularly at high water content levels and high temperatures. It is uncertain whether observed declines in decomposition rates at high temperatures are due to declines in the heat capacity of extracellular enzymes as predicted by thermodynamic theory, or due to simultaneous declines in soil moisture. It is also uncertain whether oxygen limits decomposition rates at high water contents. Here we present the results of a full factorial experiment using organic soils from a boreal forest incubated at high temperatures (25 and 35 °C), a wide range of water-filled pore space (WFPS; 15, 30, 60, 90 %), and contrasting oxygen concentrations (1 and 20 %). We found support for the hypothesis that decomposition rates are high at high temperatures, provided that enough moisture and oxygen are available for decomposition. Furthermore, we found that decomposition rates are mostly limited by oxygen concentrations at high moisture levels; even at 90 % WFPS, decomposition proceeded at high rates in the presence of oxygen. Our results suggest an important degree of interaction among temperature, moisture, and oxygen in determining decomposition rates at the soil core scale.

Nanofibrillation of TEMPO-oxidized bleached hardwood kraft cellulose at high solids content

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1077-1088 ◽  
Author(s):  
Kaarina Kekäläinen ◽  
Henrikki Liimatainen ◽  
Floriane Biale ◽  
Jouko Niinimäki
Keyword(s):  
Charge Density ◽  
Amorphous Material ◽  
Cellulose Nanofibrils ◽  
High Water ◽  
Crystalline Cellulose ◽  
High Water Content ◽  
High Solids ◽  
Bleached Kraft Pulp ◽  
Solids Content ◽  
A Charge

AbstractCellulose nanofibrils (NF) are usually produced by disintegration processes at low solids content (<5%). However, the high water content reduces the capacity of production, increases the transportation costs of NF suspensions and narrows the possible applications of NF. The goal of the present study was to test a grinding technique based on oscillatory ball milling. Bleached kraft pulp cellulose was nanofibrillated at high solids contents (≥50%), which was obtained from 2,2,6,6-tetramethylpiperidine-1-oxyl radical-oxidized pulp. The grinding method was only successful when the charge density was at least 0.5 mmol g-1. NFs and cellulose nanocrystals were identified at a charge density of 1.1 mmol g-1and a solids content of 50%. The size reduction of the formed particles was observed by means of flow fractionation and imaging and viscosity measurements after increasing the charge density from 0.3 to 1.1 mmol g-1. A solids content increment and a charge density decrement resulted in particles with low aspect ratio rather than in nanofibrils. Wide angle X-ray diffraction measurements showed the transformation of crystalline cellulose into amorphous material in the case of grounding at 93% solids content.

scholarly journals Designing robust chitosan-based hydrogels for stem cell nesting under oxidative stress

Bioimpacts ◽  
2021 ◽  
Author(s):  
Zahra Olfat Noubari ◽  
Asal Golchin ◽  
Marziyeh Fathi ◽  
Ailar Nakhlband
Keyword(s):  
Oxidative Stress ◽  
Tissue Engineering ◽  
Stem Cells ◽  
Porous Structure ◽  
High Water ◽  
High Water Content ◽  
Dapi Staining ◽  
Antioxidant Genes ◽  
Wide Range ◽  
The Impact

Introduction: Hydrogels are unique candidates for a wide range of biomedical applications including drug delivery and tissue engineering. The present investigation was designed to consider the impact of chitosan-based hydrogels as a scaffold on the proliferation of human bone marrow mesenchymal stem cells (hBM-MSCs) besides neutralization of oxidative stress in hBM-MSCs. Methods: Chitosan (CS) and CS-gelatin hydrogels were fabricated through ionic crosslinking using β-glycerophosphate. The hBM-MSCs were cultured on the prepared matrices and their proliferation was evaluated using DAPI staining and MTT assay. Furthermore, the effect of hydrogels on oxidative stress was assessed by measuring the expression of NQO1, Nrf2, and HO-1 genes using real-time PCR. Results: The developed hydrogels indicated a porous structure with high water content. The toxicity studies showed that the prepared hydrogels have a high biocompatibility/cytocompatibility. The expression of intracellular antioxidant genes was studied to ensure that stress is not imposed by the scaffold on the nested cells. The results showed that Nrf2 as a super transcription factor of antioxidant genes and its downstream antioxidant gene, NQO1 were downregulated. Unexpectedly, the upregulation of HO-1 was detected in the current study. Conclusion: The prepared CS-based hydrogels with desired properties including porous structure, high swelling ability, and cytocompatibility did not show oxidative stress for the nesting of stem cells. Therefore, they could be attractive scaffolds to support stem cells for successful tissue engineering purposes.

scholarly journals Interactions among temperature, moisture, and oxygen concentrations in controlling decomposition rates

2016 ◽  
Author(s):  
Carlos A. Sierra ◽  
Saadatullah Malghani ◽  
Henry W. Loescher
Keyword(s):  
High Temperatures ◽  
Extracellular Enzymes ◽  
High Water ◽  
High Water Content ◽  
Soil Core ◽  
Decomposition Rates ◽  
Environmental Controls ◽  
Arctic Soils ◽  
Wide Range ◽  
Oxygen Concentrations

Abstract. Determining environmental controls on soil organic matter decomposition is of importance for developing models that predict the effects of environmental change on global soil carbon stocks. There is uncertainty about the environmental controls on decomposition rates at temperature and moisture extremes, particularly at high water content levels and high temperatures. It is uncertain whether observed declines of decomposition rates at high temperatures are due to declines in the heat capacity of extracellular enzymes as predicted by thermodynamic theory, or due to simultaneous declines in soil moisture. It is also uncertain whether oxygen limits decomposition rates at high water contents. Here we present results from a full factorial experiment using organic arctic soils incubated at high temperatures (25 and 35 degrees C), a wide range of water-filled pore space WFPS (15, 30, 60, 90 %), and contrasting oxygen concentrations (1 and 20 %). We found support for the hypothesis that decomposition rates increase at high temperatures provided enough moisture and oxygen is available for decomposition. Furthermore, we found that decomposition rate is mostly limited by oxygen concentrations at high moisture levels; even at 90 % WFPS, decomposition proceeded at high rates in the presence of oxygen. Our results suggest an important degree of interactions among temperature, moisture, and oxygen in determining decomposition rates at the soil-core scale.

scholarly journals Optimalization of multiresidue method for the determination of pesticide residues in fruits

2021 ◽  
Vol 61 (3) ◽  
pp. 221-238
Keyword(s):  
Water Content ◽  
Pesticide Residues ◽  
High Water ◽  
High Water Content ◽  
Detector Response ◽  
Wide Range ◽  
Comprehensive Determination ◽  
Selective Detectors ◽  
Active Substances

The main aim of this study was to optimize the QuEChERS methodology for the comprehensive determination of pesticide residues using a simple and inexpensive gas chromatography equipped with selective detectors working simultaneously (GC-ECD/NPD). The method was validated in accordance with the SANTE/11945/2015 guidelines. Representative fruit matrices were chosen from the commodities group with high water content (apples), and with high acidity and high water content (strawberry) for a 160 compounds in the range of 0.005−0.02 mg/kg. The accuracy of the method was as required (recovery: 70–120%, precision: below 20%) for 135 active substances in apples samples and 137 in strawberries samples. The main advantages of the methodology include: good detector response linearity (R2 above 0.995), low limits of detection (0.005 mg/kg for more than 20 compounds, 0.01 mg/kg for about 120 compounds), possibility of simultaneous determination of a wide range of compounds (including some “difficult” ones) without use of a single residue methods. The simultaneous use of two selective detectors allows to obtain more data during a single dose of the sample and confirmation of the result for most compounds, which allows to prevent false positives ones.

Contribution of Soil Physical Propreties in The Assessment of Flood Risks in Tropical Areas. Case of The Mbo Plain

2021 ◽  
Author(s):  
Sylvie Noelle DJUKEM FENGUIA ◽  
David Guimolaire Nkouathio
Keyword(s):  
Chemical Properties ◽  
Infiltration Rate ◽  
High Water ◽  
Soil Samples ◽  
High Water Content ◽  
Predisposing Factor ◽  
Undisturbed Soil ◽  
Flood Risks ◽  
Physico Chemical ◽  
Permeable Soil

Abstract Flooding occurs when water is in excess and can no longer be evacuated normally. The nature of the soil has been identified as one of the major causes of flooding, hence this study aimed is to show the influence of the physico-chemical properties of the soil on the recurrence of flooding in the Mbo plain. Four soil profiles were carried out on the alluviums according to the altitudes. These profiles were described and undisturbed soil samples were taken. Then, measurements of the infiltration rate of water in the soil by the Porchet method were carried out in sixteen sites. Finally, soil samples taken by auger and core sampling were studied in the laboratory. Physico-chemical parameters such as grain size, porosity, moisture, pH, compactness and organic matter were determined. Infiltration tests carried out in situ using the Porchet method revealed a hydraulic conductivity between 10−5 and 10−7 m/s, characteristic of a semi-permeable soil. This low value of permeability results from the morpho-structural arrangement and the chemical composition of the soils of the plain. These soils are hydromorphic, which means that they are constantly flooded and temporarily waterlogged. They are more or less sandy-clay on the surface, and very clayey at depth, generally from 25 cm. The very clayey soils at the base considerably slow down infiltration and act as a real barrier layer that prevents water from infiltrating, resulting to intense runoff. These soils are very porous and compact with a fairly high water content of up to 71%. This work allows us to conclude on the role of intrinsic soil properties on the genesis of floods in lowland areas. As in many plains in Africa and in the world, the nature of the soil in the Mbo plain is a natural predisposing factor to flood risks. The methods used can be applied in areas with the same characteristics as the Mbo Plain.

scholarly journals Development of Water-in-Oil Emulsions as Delivery Vehicles and Testing with a Natural Antimicrobial Extract

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2105
Author(s):  
Giovana Colucci ◽  
Arantzazu Santamaria-Echart ◽  
Samara C. Silva ◽  
Isabel P. M. Fernandes ◽  
Caroline C. Sipoli ◽  
...  
Keyword(s):  
Tween 80 ◽  
High Water ◽  
High Water Content ◽  
Cinnamon Extract ◽  
Fluid Systems ◽  
Natural Oil ◽  
Span 80 ◽  
Oil Emulsions ◽  
The Stability ◽  
The One

Water-in-oil (W/O) emulsions have high potential for several industrial areas as delivery systems of hydrophilic compounds. In general, they are less studied than oil-in-water (O/W) systems, namely in what concerns the so-called fluid systems, partly due to problems of instability. In this context, this work aimed to produce stable W/O emulsions from a natural oil, sweet almond oil, to be further tested as vehicles of natural hydrophilic extracts, here exemplified with an aqueous cinnamon extract. Firstly, a base W/O emulsion using a high-water content (40/60, v/v) was developed by testing different mixtures of emulsifiers, namely Tween 80 combined with Span 80 or Span 85 at different contents. Among the tested systems, the one using a 54/46 (v/v) Span 80/Tween 80 mixture, and subjected to 12 high-pressure homogenizer (HPH) cycles, revealed to be stable up to 6 months, being chosen for the subsequent functionalization tests with cinnamon extract (1.25–5%; w/v; water-basis). The presence of cinnamon extract leaded to changes in the microstructure as well as in the stability. The antimicrobial and antioxidant analysis were evidenced, and a sustained behavior compatible with an extract distribution within the two phases, oil and water, in particular for the higher extract concentration, was observed.

scholarly journals Experimental analysis of the effect of electrokinetic treatment of soils

2019 ◽  
Vol 92 ◽  
pp. 11020
Author(s):  
Sara Gargano ◽  
Stefania Lirer ◽  
Barbara Liguori ◽  
Alessandro Flora
Keyword(s):  
Mechanical Properties ◽  
Sea Water ◽  
Tap Water ◽  
Chemical Properties ◽  
High Water ◽  
High Water Content ◽  
Electrokinetic Treatment ◽  
Macro Scale ◽  
Long Time ◽  
The University

In Europe, large amounts of materials are dredged annually to maintain channels and harbour activities. Consolidation processes in dredged sediments take very long-time due to the high-water content, much more than those considered in the typical problems of geotechnical engineering. The electrokinetic treatment (EK) can be an effective technique to accelerate the dewatering of these sediments and, at the same time, to improve their mechanical properties. An experimental research is under course at the University of Napoli Federico II with the aim to analyse the effects induced by EK treatments on the physic-chemical and mechanical properties of two different soils. Some laboratory tests have been carried out in a special apparatus (special oedometer) adopting two different pore fluids (tap water and sea water). The laboratory results show that the effect of EK treatment, both in terms of induced water flow and improvement of soil mechanical properties, is affected by the chemical properties of the pore fluid and by the physical and mineralogical characteristics of the particles. The results obtained at the macro-scale (specimen) have been analysed at the micro-scale by means of X-ray diffraction analysis and Scanning Electron Microscopy, comparing the microstructures of treated and untreated soils specimens.

Fluorescence sensors for detection of water based on tetraphenylethene–anthracene possessing both solvatofluorochromic properties and aggregation-induced emission (AIE) characteristics

2021 ◽  
Vol 45 (9) ◽  
pp. 4164-4173
Author(s):  
Yuta Mise ◽  
Keiichi Imato ◽  
Takashi Ogi ◽  
Nao Tsunoji ◽  
Yousuke Ooyama
Keyword(s):  
Water Content ◽  
High Water ◽  
Fluorescence Sensor ◽  
High Water Content ◽  
Fluorescence Sensors ◽  
Aggregation Induced Emission ◽  
Emission Enhancement ◽  
Wide Range ◽  
Water Based

TPE-(An-CHO)4 has been developed as an SFC (solvatofluorochromism)/AIEE (aggregation-induced emission enhancement)-based fluorescence sensor for detection of water over a wide range from low to high water content regions in solvents.

scholarly journals Oxidation Lipid on Fish Cake Catfish (Pangasius sp.) Dissolved in The Extract of Bay Leaf (Eugenia polyantha)

2020 ◽  
Vol 8 (3) ◽  
pp. 91
Author(s):  
Mahiastuti Tribuana Tungga Dewi ◽  
Boedi Setya Rahardja ◽  
Agustono Agustono
Keyword(s):  
Water Content ◽  
Natural Antioxidants ◽  
High Water ◽  
Experimental Methods ◽  
Quality Score ◽  
High Water Content ◽  
Antioxidant Compounds ◽  
White Meat ◽  
Wide Range ◽  
Significant Difference

Catfish (Pangasius sp.) As a source of animal protein. Fish catfish have a thick white meat so that it can be processed into a wide range of diversified products. The process of fried fish cake can result in fat or autooxidation process. Autooxidation can be inhibited by the presence of antioxidant compounds. One source of natural antioxidants are bay leaf Eugenia polyantha.This research was carried out by experimental methods and the use of experimental design of randomized Complete Design (RAL). RAL is used when the material and condition of the experiment are homogeneous. This research consists of four concentrations of extract treatment bay leaf, namely 0%, 10%, 20%, 30%. Fish cake has been fried done soaking for 30 minutes. Water content showed no significant difference (p> 0.05) at 24 hours to 28, this indicated that the addition of bay leaf extract did not affect the moisture content during storage. The high water content at 0 hour is caused by the process of soaking the fish cake  in the extract solution. The highest value is shown by the concentration of 30% at the hour to 0 that is 52.78%, this indicates that the fish cake by soaking can meet the quality score SNI 7757:2013 which is a maximum of 60%. The fat content in the fish cake continues to decrease, indicating the occurrence of oxidation during storage. Levels of TBA in fish cake continue to increase that can be slowed by the extract of bay leaves with a concentration of 30%.

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