Effects of microorganism within organic matter on the mechanical behaviour of solidified municipal dredged mud

2020 ◽  
Vol 57 (12) ◽  
pp. 1832-1843 ◽  
Author(s):  
Yongfeng Deng ◽  
Jun Wu ◽  
Yunzhi Tan ◽  
Yujun Cui ◽  
Chao-sheng Tang ◽  
...  
Keyword(s):  
Organic Matter ◽  
High Throughput Sequencing ◽  
Ph Value ◽  
Treatment Method ◽  
Drying Method ◽  
Oven Drying ◽  
Microbial Identification ◽  
Loading Method ◽  
Pre Treatment

Municipal mud consists of organic matter naturally deposited in a microbial-rich environment, and its common pre-treatment in the laboratory is normally different from that in situ. In this study, an improved pre-loading method and the common pre-treatment method (by air or oven drying) were first applied to investigate the effect of microorganisms within organic matter on performance of the solidified soils. Results reveal that (i) Atterberg limits in the pre-loading method were higher than those in the drying method; (ii) the time-dependent strength became stable for the solidified soils pre-treated by the drying method, while strength decreased for the soils pre-treated by the pre-loading method; (iii) pH value of solidified soils by the pre-loading method decreased more significantly. After excluding the possible porosity influence on solidified soils, the effects of microorganisms within organic matter were investigated by microbial identification tests, including fluorescence detection and high-throughput sequencing. The pre-treatment procedure changed the vitality and diversity of microorganisms, leading to a rebalance between acid erosion and cement hydration during long-term curing. At the end, the long-term strength of the solidified municipal mud by the traditional pre-treatment method (by air or oven drying) could be overevaluated.

EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

1995 ◽  
Vol 53 ◽  
pp. 538-539
Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher
Keyword(s):  
Steel Surface ◽  
Surface Preparation ◽  
Treatment Method ◽  
Chrome Plating ◽  
Transmission Electron ◽  
Alloy Steels ◽  
Pre Treatment ◽  
Hard Chrome ◽  
Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

scholarly journals Changes in the hydrochemical regime of Onegо Lake since the early 1990s

2019 ◽  
pp. 62-72 ◽  
Author(s):  
N. M. Kalinkina ◽  
E. V. Tekanova ◽  
A. V. Sabylina ◽  
A. V. Ryzhakov
Keyword(s):  
Organic Matter ◽  
River Water ◽  
Ph Value ◽  
Correlation Coefficients ◽  
Climatic Conditions ◽  
Allochthonous Organic Matter ◽  
Hydrochemical Regime ◽  
First Time ◽  
Liquid Precipitation

The supply of allochthonous organic matter with river water to the lakes rises in the new climatic conditions of Karelia (mild winters, an increase in the amount of liquid precipitation, less freezing of the soil). In connection with the geochemical peculiarities of Fennoscandia, more quantity of humic substances in a complex with iron and phosphorus enter the water bodies. These processes can lead to a change in the hydrochemical regime, water quality and habitat of the biota. For the first time for lakes of Karelia, long-term changes (1963–2017) of parameters, which are markers of allochthonous organic matter, were estimated on the example of Petrozavodsk Bay of Onego Lake. It was found that since the 1990s, the following characteristics significantly increase in Petrozavodsk Bay water: the color of water (from 56 to 73 degrees), the content of suspended matter (from 1.6 to 3 mg/l), iron (from 0.12 to 0.42 mg/l), phosphorus (from 12 to 22 μg/l). This leads to changes in the carbonate system of the bay water. The concentration of carbon dioxide increases significantly (from 1.2 to 3.0 mg/l), the pH value drops (from 7.22 to 7.12) and the oxygen content diminishes (from 101 to 92% of saturation). The Spearman correlation coefficients between the chemical characteristics and the year of study were the highest for the spring period, when the bay is separated from the open part of the lake by thermal bar and is strongly influenced by river water. Simultaneously with the change in the hydrochemical regime, there is an increase in the amount of iron in the upper layer of silts (from 0.65 to 4.8% of the air-dry sample). This led to a decrease in the number of macrozoobenthos 6–7 times.

scholarly journals Proximate Analysis of Goat Milk Yogurt Powder Produced by Freeze Drying and Vacuum-Oven Drying and in Comparing with Freeze-Dried Yogurt Powder Prepared with Tualang Honey

2021 ◽  
Vol 12 (1S) ◽  
pp. 101-111
Author(s):  
Siti Norhannani Ahmat Azemi ◽  
Norshafiqah Zainul ◽  
Asmaliza Abd. Ghani ◽  
John Tang Yew Huat
Keyword(s):  
Moisture Content ◽  
Protein Content ◽  
Freeze Drying ◽  
Ph Value ◽  
Goat Milk ◽  
Drying Method ◽  
Vacuum Oven ◽  
Oven Drying ◽  
Freeze Dried ◽  
Tualang Honey

This study was carried out to produce powdered yogurt from goat milk with longer shelf life.Two methods of drying process of yogurt were used which are vacuum-oven drying (VD) and freezedrying (FD). Goat milk yogurt powder prepared with added Tualang honey (TH) was produced by freeze-drying method. In this study, four formulations of yogurt were prepared with the addition of commercial yogurt containingas starter culture.Granulated sugar was added about 8% into the yogurt as control sample. While other three yogurts were prepared with 8% of Tualang honey, 6% of Tualang honey with 2% of sugar and 4% of Tualang honey with 4% of sugar. The proximateanalysis was used in order to identify the proximate composition and pH value of the yogurt. The moisture content of goat milk yogurt, VD goat yogurt powder and FD goat yogurt powder were 79.20%, 8.22% and 9.66% respectively. While, the moisture content for FD goat yogurt powder with addition of 4%, 6% and 8% Tualang honey were 15.12%,15.92% and 13.53% respectively.While the value of ash content for FD goat milk yogurt powder with addition of 4%, 6% and 8% Tualang honey were 0.37%, 0.35% and 0.50% respectively. The total protein content for goat milk yogurt was 4.61% whilein VD goat yogurt powder and FD goat yogurt powder were 15.04% and 15.07% respectively. The value of protein content for FD goat milk yogurt powder with addition of 8% of Tualang honey was 15.38%. The pH value ofgoat milk sample and fresh yogurt goat milk were 6.52 and 3.82. The pH values for fresh yogurt with addition of 4%, 6% and 8% of Tualang honey were 4.64, 4.68 and 4.73.Vacuum-oven drying method and freeze-drying method did not show any significant different in moisture, ash and protein content but showed significant different in pH value.

scholarly journals Assessment of Photocatalytic Hydrogen Production from Biomass or Wastewaters Depending on the Metal Co-Catalyst and Its Deposition Method on TiO2

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 584 ◽  
Author(s):  
Mikel Imizcoz ◽  
Alberto V. Puga
Keyword(s):  
Hydrogen Production ◽  
Noble Metals ◽  
Treatment Method ◽  
H2 Production ◽  
Catalyst Loading ◽  
Co Catalyst ◽  
Photocatalytic Hydrogen Production ◽  
Loading Method ◽  
Pre Treatment ◽  
Loading Methods

A systematic study on the solar photocatalytic hydrogen production (photoreforming) performance of M/TiO2 (M = Au, Ag, Cu or Pt) using glucose as a model substrate, and further extended to lignocellulose hydrolysates and wastewaters, is herein presented. Three metal (M) co-catalyst loading methods were tested. Variation of the type of metal results in significantly dissimilar H2 production rates, albeit the loading method exerts an even greater effect in most cases. Deposition-precipitation (followed by hydrogenation) or photodeposition provided better results than classical impregnation (followed by calcination). Interestingly, copper as a co-catalyst performed satisfactorily as compared to Au, and slightly below Pt, thus representing a realistic inexpensive alternative to noble metals. Hydrolysates of either α-cellulose or rice husks, obtained under mild conditions (short thermal cycles at 160 °C), were rich in saccharides and thus suitable as feedstocks. Nonetheless, the presence of inhibiting byproducts hindered H2 production. A novel photocatalytic UV pre-treatment method was successful to initially remove the most recalcitrant portion of these minor products along with H2 production (17 µmol gcat−1 h−1 on Cu/TiO2). After a short UV step, simulated sunlight photoreforming was orders of magnitude more efficient than without the pre-treatment. Hydrogen production was also directly tested on two different wastewater streams, that is, a municipal influent and samples from operations in a fruit juice producing plant, with remarkable results obtained for the latter (up to 115 µmol gcat−1 h−1 using Au/TiO2).

scholarly journals Effect of Calcium Cyanamide on Soil Fungal Community in Successive Tea-Cuttings Nursery

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 716
Author(s):  
Qinli Qiu ◽  
Dongmei Fan ◽  
Yinmao Wang ◽  
Danyi Huang ◽  
Yu Wang ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
High Throughput Sequencing ◽  
Aluminum Toxicity ◽  
Ph Value ◽  
Alpha Diversity ◽  
Pathogenic Fungi ◽  
Available Phosphorus ◽  
Calcium Cyanamide ◽  
Exchangeable Al

The effects of calcium cyanamide on the soil fungal communities in successive tea-cuttings nursery soils were investigated based on Illumina high-throughput sequencing. The field experiment was carried out with three treatments, including control (CK), flooding (F) and calcium cyanamide (CC). The treatment with calcium cyanamide increased pH (~1 unit) and reduced the accumulation of phenols (~50%), available phosphorus (~28%) and exchangeable Al (~90%) significantly, and improved soil quality. The predominant phylum in all treatments was Ascomycota. FUNGuild revealed that the dominant trophic mode was saprotrophy in tea-cuttings nursery soil. Plant pathogens had a low abundance in the calcium cyanamide treatment. Alpha diversity analysis showed lower richness in the calcium cyanamide than the other treatments. Network analysis showed a poorly connected but highly modularized network in the calcium cyanamide treatment, with the crucial OTUs functions related to anti-pathogenicity. The results showed that calcium cyanamide should be recommended for improving long-term tea nurseries by increasing the survival rate of tea seedlings due to increasing soil pH value, reducing aluminum toxicity, decreasing the accumulation of polyphenols, diminishing pathogenic fungi and making the taxa related to anti-pathogenicity occupy a more important niche.

scholarly journals PRODUCTION OF BIOETHANOL FROM RICE STRAW USING YEAST EXTRACTS PEPTONE DEXTROSE

2016 ◽  
Vol 36 (1) ◽  
pp. 296-301
Author(s):  
DY Tsunatu ◽  
KG Atiku ◽  
TT Samuel ◽  
BI Hamidu ◽  
DI Dahutu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Particle Size ◽  
Rice Straw ◽  
Substrate Concentration ◽  
Ph Value ◽  
Lignin Content ◽  
Treatment Method ◽  
Optimum Conditions ◽  
Fermentation Time ◽  
Pre Treatment

The production of bio-ethanol from Rice Straw (Oryza sativa) was carried out using rice straw as a feedstock and a combination of Yeast Extracts Peptone Dextrose (YEPD)at 0.2%(w/v) 0.4%(w/v), 0.6%(w/v), 0.8%(w/v) and 1%(w/v) concentrations and Saccharomyces cerevisiae (yeast) at 0.5% (w/v), 1%(w/v), 1.5%(w/v), 2%(w/v) and 2.5%(w/v) concentrations as cells for fermentation. The study determined the most suitable pre-treatment method from the following pretreatment methods; 1M NaOH and heating. IM NaOH pre-treatment gave the highest cellulose and lowest lignin content. The effects of substrate concentration values of 1g/l, 2g/l, 4g/l, 6g/l and 8g/l; with particle size of 300μm and cell loading combination of YEPD at 0.2%(w/v) 0.4%(w/v), 0.6%(w/v), 0.8%(w/v), 1%(w/v) concentrations and Saccharomyces cerevisiae (yeast) at 0.5% (w/v), 1%(w/v), 1.5%(w/v), 2%(w/v), 2.5%(w/v) on the fermentation process were investigated to obtain optimum conditions of fermentation. The optimum conditions of fermentation were obtained at temperature of 330C, pH value of 4.0, substrate concentration of 4g/l, particle size 300μm and YEPD to yeast ratio of 0.8/1.5 after 72 hours of fermentation time. Also substrate concentration of 4g/l, gave highest bioethanol yield of 49.50%. http://dx.doi.org/10.4314/njt.v36i1.36

Sample pre-treatment and the determination of some chemical properties of acid sulfate soil materials

Soil Research ◽  
2004 ◽  
Vol 42 (6) ◽  
pp. 667 ◽  
Author(s):  
Crystal A. Maher ◽  
Leigh A. Sullivan ◽  
Nicholas J. Ward
Keyword(s):  
Organic Matter ◽  
Chemical Properties ◽  
Water Soluble ◽  
Acid Sulfate Soil ◽  
Acid Sulfate ◽  
Systematic Analysis ◽  
Oven Drying ◽  
Soluble Sulfate ◽  
Pre Treatment

This study provides a systematic analysis of the effect of common acid sulfate soil (ASS) sample pre-treatments (namely freezing, oven drying, and grinding) on chromium-reducible sulfur (SCR) and water-soluble sulfate determinations. The results show that oven drying and hand grinding of the samples prior to analysis resulted in a decrease in SCR (i.e. up to 20% compared to those of frozen samples). This lower SCR value was partly due to the oxidation of sulfides in the oven. For oven-dried ASS materials, more intensive grinding in a ring mill increased SCR values, most likely by abrading coatings from pyrite grains. For oven-dried mineral ASS materials the highest SCR values were obtained with 1 min of ring mill grinding, but for soils with appreciable organic matter (such as peat), 5 min of ring mill grinding gave the highest values. The results indicate that for some ASS materials, oven drying, regardless of the ensuing grinding procedure, results in underestimated SCR values. This study also demonstrates that an artifact of oven drying ASS materials can be greatly increased water-soluble sulfate contents.

Continuous Positive Airway Pressure (CPAP) Therapy for the Treatment of Hypernasality: A Single Case Study

2014 ◽  
Vol 24 (2) ◽  
pp. 48-58 ◽  
Author(s):  
Lakshmi Kollara ◽  
Graham Schenck ◽  
Jamie Perry
Keyword(s):  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Single Case ◽  
Treatment Method ◽  
Post Treatment ◽  
Subjective Perception ◽  
Cpap Therapy ◽  
Long Term Follow Up

Studies have investigated the applications of Continuous Positive Airway Pressure (CPAP) therapy in the treatment of hypernasality due to velopharyngeal dysfunction (VPD; Cahill et al., 2004; Kuehn, 1991; Kuehn, Moon, & Folkins, 1993; Kuehn et al., 2002). The purpose of this study was to examine the effectiveness of CPAP therapy to reduce hypernasality in a female subject, post-traumatic brain injury (TBI) and pharyngeal flap, who presented with signs of VPD including persistent hypernasality. Improvements in mean velopharyngeal orifice size, subjective perception of hypernasality, and overall intelligibility were observed from the baseline to 8-week post-treatment assessment intervals. Additional long-term assessments completed at 2, 3, and 4 months post-treatment indicated decreases in immediate post-treatment improvements. Results from the present study suggest that CPAP is a safe, non-invasive, and relatively conservative treatment method for reduction of hypernasality in selected patients with TBI. More stringent long-term follow up may indicate the need for repeated CPAP treatment to maintain results.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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