MINERALIZATION OF UREA–FORMALDEHYDE COMPOUNDS AT DIFFERENT pH LEVELS AND TEMPERATURES

1964 ◽  
Vol 44 (1) ◽  
pp. 131-136 ◽  
Author(s):  
J. Basaraba
Keyword(s):  
Incubation Period ◽  
Total Nitrogen ◽  
Main Product ◽  
Urea Formaldehyde ◽  
Growing Season ◽  
Nitrate Production ◽  
Laboratory Results ◽  
Initial Ph ◽  
Different Temperatures

Mineralization of urea-form fertilizer materials was studied in soils at two different pH levels and five different temperatures. Results show that the nitrogenous materials decomposed very slowly but progressively throughout the incubation period of 14 weeks, and that nitrate was the main product formed. The rates of nitrate production from the urea-form compounds were, in general, from 2 to 5% higher in soil with an initial pH 5.7 than in soil having an initial pH 7.0. At the end of the incubation period, the quantities of nitrate formed from the two urea-form compounds were about equal, amounting to 20, 28, 40, 50, and 58% of the total nitrogen added at 10, 15, 20, 25, and 30 °C respectively. The laboratory results suggested that the urea-form materials studied here could be of only limited value to plants if applied to soils with temperatures below 15 °C during the growing season.

scholarly journals Kinetics and Mechanism of the Change of the 4-Nitrobenzylthio-System into 4,4′-Diformylazoxybenzene in Alkaline Dioxane-Water Media

1985 ◽  
Vol 40 (11) ◽  
pp. 1128-1132
Author(s):  
Y. Riad ◽  
Adel N. Asaad ◽  
G.-A. S. Gohar ◽  
A. A. Abdallah
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Rate Constants ◽  
Main Product ◽  
Reaction Medium ◽  
Aqueous Dioxane ◽  
Proton Abstraction ◽  
First Order ◽  
Water Media ◽  
Different Temperatures

Sodium hydroxide reacts with α -(4-nitrobenzylthio)-acetic acid in aqueous-dioxane media to give 4,4'-diformylazoxybenzene as the main product besides 4,4'-dicarboxyazoxybenzene and a nitrone acid. This reaction was kinetically studied in presence of excess of alkali in different dioxane-water media at different temperatures. It started by a fast reversible a-proton abstraction step followed by two consecutive irreversible first-order steps forming two intermediates (α -hydroxy, 4-nitrosobenzylthio)-acetic acid and 4-nitrosobenzaldehyde. The latter underwent a Cannizzaro's reaction, the products of which changed in the reaction medium into 4,4'-diformylazoxybenzene and 4,4'-dicarboxyazoxybenzene. The rate constants and the thermodynamic parameters of the two consecutive steps were calculated and discussed. A mechanism was put forward for the formation of the nitrone acid.Other six 4-nitrobenzyl, aryl sulphides were qualitatively studied and they gave mainly 4,4'-diformylazoxybenzene beside 4,4'-dicarboxyazoxybenzene or its corresponding azo acid.

TEMPERATURE IN RELATION TO THE TRANSMISSION AND PATHOGENICITY OF WHEAT STRIATE MOSAIC VIRUS

1964 ◽  
Vol 42 (9) ◽  
pp. 1123-1133 ◽  
Author(s):  
J. T. Slykhuis ◽  
P. L. Sherwood
Keyword(s):  
Mosaic Virus ◽  
Incubation Period ◽  
Spring Wheat ◽  
Early Summer ◽  
Wheat Seedlings ◽  
Acquisition Access Period ◽  
The North ◽  
Different Temperatures ◽  
North American Type ◽  
Test Plants

Endria inimica Say acquired the North American type of wheat striate mosaic virus during periods of 15 minutes or longer on diseased plants held at five constant temperatures ranging from 10 to 33 °C. When infective insects were given inoculation access periods varying from 1 to 4 days at different temperatures, the percentage of test plants infected increased with temperature from 12.5% at 10° to 81.4% at 33 °C. After an acquisition access period of 2 days at 24 °C, insects kept at 8 or 10 °C did not transmit virus, but the percentage of others that transmitted at successively higher temperatures increased from 3.3% at 16 °C to 73.3% at 33 °C. The preinfective period was more than 29 days for insects kept at 16 °C and only 5 days for some kept at 27, 30, and 33 °C. The average preinfective period was 11 days at 20 °C, but decreased to 6.4 days as temperature increased to 33 °C. The percentage of test plants that became infected increased from 0.1% at 16 °C to 44.3%, at 33 °C. Stewart and Ramsey wheat seedlings exposed to infective E. inimica for 2 days did not develop symptoms during a subsequent 60 day period at 10 °C. After the same plants were placed in a greenhouse at 20–25 °C, 26% and 27%, respectively, developed symptoms. The incubation period for symptoms in plants ranged from 17 to more than 62 days at 16 °C. It decreased as temperature increased but varied from 6 to 25 days at 30 °C. Forty-two and 48% of Stewart and Ramsey wheat plants respectively, developed symptoms at 16 °C, and increased to almost 100% for both varieties at 30 and 33 °C. The above results indicate that high temperatures during early summer are prerequisite for severe epidemics of wheat striate mosaic in spring wheat.

Aflatoxin Production in Black Currant, Blueberry and Strawberry Jams

1978 ◽  
Vol 41 (5) ◽  
pp. 344-347 ◽  
Author(s):  
O. PENSALA ◽  
A. NISKANEN ◽  
S. LINDROTH
Keyword(s):  
Yeast Extract ◽  
Raw Materials ◽  
Fungal Growth ◽  
Dry Weight ◽  
Aflatoxin Production ◽  
Fungal Mycelium ◽  
Black Currant ◽  
Initial Ph ◽  
Different Temperatures ◽  
Yeast Extract Sucrose

Unsweetened and sweetened (20 and 44% sucrose) black currant, blueberry and strawberry jams with spores of Aspergillus parasiticus NRRL 2999 were incubated at different temperatures and atmospheres for 0.5, 1, 2, and 6 months. Hyphal dry weight, pH of medium and aflatoxin production were examined. Also, the aflatoxin distribution between mold and jam layers was examined in jam with uncontrolled and controlled pH (initial pH 3.1–3.6 and 5.6 respectively) and in 20% yeast extract sucrose broth (initial pH 5.6) after 2 weeks of incubation. Aflatoxin was observed in black currant and strawberry jams stored at 22 and 30 C, but not in blueberry jam. Addition of sugar prevented production of aflatoxin in detectable amounts, although it enhanced fungal growth. Storage at 4 C resulted in a marked reduction in fungal growth. The high CO2 atmosphere prevented production of aflatoxin in detectable amounts in black currant and blueberry jams but not in strawberry jam. Raising the initial pH of the stored jam caused an increase in aflatoxin synthesis, although the amount of fungal mycelium, in contrast was reduced. Aflatoxin synthesis as a function of fungal growth was significantly weaker in the jams than in the yeast extract sucrose broth. The results imply that the jam raw materials, particularly blueberry, contain substances inhibiting production of atlatoxins. Alternatively, it is also possible that the jam materials contain only small amounts of nutrients necessary for synthesis of aflatoxin.

scholarly journals Co-Digestion of Vinasse Waste and Tofu Liquid Waste to Increase Biogas Production

Eksergi ◽  
2015 ◽  
Vol 12 (2) ◽  
pp. 23
Author(s):  
Iqbal Syaichurrozi
Keyword(s):  
Nitrogen Content ◽  
Total Nitrogen ◽  
Biogas Production ◽  
Liquid Waste ◽  
Volume Ratio ◽  
Total Nitrogen Content ◽  
Anaerobic Digesters ◽  
Initial Ph

The purpose of this study was to increase biogas production using co-digestion concept. Vinasse Waste (VW) containing high COD and low total Nitrogen content was mixtured with Tofu Liquid Waste (TLW) containing low COD and high total Nitrogen. Substrates were varied with volume ratio of VW:TLW of 100:0, 20:80, 0:100. Total volume of substrates was 250 mL. Anaerobic digesters were operated at room temperatur. After fermentation, biogas total volume of variables of 100:0, 20:80, 0:100 was 88.5; 125.5; 41.5 mL. Initial pH for all variables was 7.0. At the end of fermentation, pH substrates became 3.9; 5.1; 6.8 for variables of 100:0, 20:80, 0:100 respectively.

Improvement of delta-endotoxin production from local Bacillus thuringiensis Se13 using Taguchi’s orthogonal array methodology

2018 ◽  
Vol 43 (6) ◽  
pp. 662-670 ◽  
Author(s):  
Ardahan Eski ◽  
Zihni Demirbağ ◽  
İsmail Demir
Keyword(s):  
Bacillus Thuringiensis ◽  
Incubation Period ◽  
Orthogonal Array ◽  
Incubation Temperature ◽  
Taguchi Methods ◽  
Optimum Level ◽  
Optimum Conditions ◽  
Delta Endotoxin ◽  
Initial Ph ◽  
Four Levels

Abstract Objective The insecticidal activity of Bacillus thuringiensis directly depends on the yield of delta-endotoxins. In this study, various nutritional and cultural parameters influencing delta-endotoxin synthesis by a local isolate of B. thuringiensis Se13 were investigated using Taguchi methods. Methods In the first experiment, four factors, incubation period, incubation temperature, initial pH and medium, each at four levels, were selected and an orthogonal array layout of L16 was carried out. In the second experiment, Taguchi’s orthogonal array method of L27 was used to evaluate the effects of the different concentration of medium components. Taguchi’s signal–noise ratio and variance analysis were applied to determine the effect of the factors. After each experiment, verification studies were carried out using determined optimum conditions. Results The optimum conditions for incubation period, incubation temperature, initial pH, and medium determined as 72 h, 30°C, pH 9, and M4 medium, respectively. In the second experiment, soybean flour (5%), glucose (5%), KH2PO4 (0.3%), K2HPO4 (0.1%), MgSO4 (0.4%) were determined as the optimum conditions. The delta-endotoxin yield was elevated to 1559.25 μg mL−1 when the factors were adjusted to optimum level. Conclusion Optimization using the Taguchi method appeared to be a good choice for the overproduction of delta-endotoxin.

Foodborne Outbreak investigation: Al-Ahsa, Saudi Arabia, 2021. A retrospective cohort study (Preprint)

2022 ◽  
Author(s):  
Abdulmohsen Alahmad ◽  
Shady Abdulrahman Kamel
Keyword(s):  
Abdominal Pain ◽  
Incubation Period ◽  
Retrospective Cohort ◽  
Gastrointestinal Symptoms ◽  
Control Measures ◽  
P Value ◽  
Food History ◽  
Food Items ◽  
Number Of Patients ◽  
Laboratory Results

BACKGROUND On 10 September 2021, Al-Ahsa General Health Directorate reported unexpected number of patients had presented with gastrointestinal symptoms. All the patients gave a history of sharing a common meal as they ate from dinner was served at the mother's house the day before. OBJECTIVE We investigated to verify the outbreak, determine its magnitude, identify the source and implement control measures. METHODS A retrospective cohort design was conducted. Cases were defined as any person who ate dinner at the family gathering on the 9th of September 2021 and developed any or a combination of the following symptoms: diarrhea, vomiting, fever, or abdominal pain within 26 hours of food consumption. We collected information on demographics, symptoms, and food history using a semi-structured questionnaire. We reviewed hospital records for symptoms and Vital sings. We reviewed available laboratory results for cases, we conducted active case search to identify more cases. statistical analyses were performed using SPSS 21.0. RESULTS Twenty subjects were defined as cases (74%) and seven as non-cases (26%). among cases, 16 were females (80%), and 4 were males (20%). The ages ranged between 2–70 years. Among cases (59.3%) had vomiting, (59.3%) had a fever, (48.1%) developed diarrhea, (25%) abdominal pain. The incubation period ranged from 10-26 hours (mean 17.8). The relative risks and p- value were calculated for food items to assess the association between consumption of individual food items and subsequent illness. Among 8 food items consumed, red pasta with chicken (Relative Risk RR= 3.14, 95% CI = 3.2-424.6) and pizza (RR= 1.73, 95% CI = 1.74-42.2) were significantly associated with illness. CONCLUSIONS According to the epidemiological investigation, symptoms, incubation period, and laboratory results there might be some differential diagnosis, but we were unable to more definitively identify the source of the outbreak. We recommend more education to the households about food safety

Study on the Conversion of Ammonia by Electrochemical Oxidation

2013 ◽  
Vol 807-809 ◽  
pp. 1355-1361
Author(s):  
Fang Yuan ◽  
Jin Guo Dai ◽  
Zhi Hui Liang ◽  
Hong Bo Fan ◽  
Si Hao Lv
Keyword(s):  
Electrochemical Oxidation ◽  
Removal Efficiency ◽  
Total Nitrogen ◽  
Ammonia Removal ◽  
Alkaline Condition ◽  
High Concentration ◽  
Oxidation Method ◽  
Electrolysis Process ◽  
Initial Ph ◽  
Nitrate And Nitrite

The removal of high concentration ammonia in wastewater was investigated by an indirect electrochemical oxidation method using titanium electrodes coated with ruthenium and iridium (RuO2-IrO2-TiO2/Ti). The effect of different initial pH on ammonia removal by electrochemical oxidation was studied. The concentrations variation of ammonia, total nitrogen, nitrate nitrite, and free cholorines, chloramines was analyzed under the conditions with and without pH controlling. The results indicate that ammonia removal efficiency was higher under the moderate alkaline condition than that under neutral one. During the electrolysis process, nitrate and nitrite concentrations were very low, even below their detecting limits. The concentrations of free chlorines and chloramines were significantly affected by pH, as trichloramine and free chlorines were mainly produced in the reaction without pH controlling, while monochloramine was mainly produced in a stable alkalescene.

scholarly journals STUDY ON THE GROWTH OF BACILLUS VELEZENSIS M2 AND APPLYING IT FOR TREATMENT OF THE CATTLE SLAUGHTERHOUSE WASTEWATER

2018 ◽  
Vol 54 (4A) ◽  
pp. 213 ◽  
Author(s):  
Tran Thi Thu Lan
Keyword(s):  
Total Nitrogen ◽  
Large Scale ◽  
Nitrogen Concentration ◽  
High Ability ◽  
Biological Product ◽  
Bacillus Velezensis ◽  
Slaughterhouse Wastewater ◽  
Total Nitrogen Concentration ◽  
Initial Ph ◽  
Time Of Operation

Wastewater from cattle slaughterhouse usually contains high COD and total nitrogen concentration, which required to be treated properly in order to prevent pollution. Strain Bacillus velezensis M2 isolated from Thinh An slaughterhouse, has high ability to degrade organic pollutants rapidly and, therefore, it can be used to produce biological product for slaughterhouse wastewater treatment in large scale, thus reduce setting-up time of operation. In this study, we showed that the best conditions for Bacillus velezensis M2 to grow are NA medium, initial pH of 6.5, inoculum of 3 % (v/v), shaking of 200 rpm. For test in laboratory-scale of 500 ml flask, Bacillus velezensis M2 was induced in the cattle slaughterhouse water containing COD of 1260 mg/L and total nitrogen of 137 mg/L, shaking at 200 rpm, inoculum 3 %, after 12 hours the removal efficiency in COD and total nitrogen were 93.2 % and 83.5 %, respectively.

scholarly journals Preparation and stability of microcapsule wood preservative from neem extract

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3352-3363
Author(s):  
Luchen Liu ◽  
Guoqi Xu
Keyword(s):  
Urea Formaldehyde ◽  
Antibacterial Properties ◽  
Wood Preservative ◽  
Environmental Stability ◽  
Wall Material ◽  
Melia Azedarach ◽  
Water Spray ◽  
Neem Extract ◽  
Decay Test ◽  
Different Temperatures

Neem (Melia azedarach) extract has good antibacterial properties, but its bioactivities are easily decomposed. In order to protect the bioactivities of neem extract, melamine urea formaldehyde (MUF) was used as wall material to prepare a wood microcapsule preservative. The size and distribution of microcapsules after treatments at different temperatures were determined by microscopy. These observations showed that increases in temperature caused the microcapsule particles to become smaller and more evenly distributed. The stability of this preservative was studied by use of an environmental factors experiment (ultraviolet light, condensation, and water spray) and a decay test. The results indicated that the microcapsule preservative from neem extract was more stable than the neem extract preservative. The results indicated that the microcapsule preservative from neem extract showed acceptable environmental stability. The water spray resistance of microcapsule preservative from neem extract was the best.

scholarly journals EFFECT OF CULTURE CONDITIONS FOR ANTIMICROBIAL ACTIVITY OF MARINE - DERIVED FUNGUS ASPERGILLUS FLOCCULOSUS 01NT.1.1.5

2018 ◽  
Vol 15 (4) ◽  
pp. 721-728
Author(s):  
Phan Thi Hoai Trinh ◽  
Ngo Thi Duy Ngoc ◽  
Vo Thi Dieu Trang ◽  
Phi Quyet Tien ◽  
Bui Minh Ly ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Secondary Metabolites ◽  
Incubation Period ◽  
Marine Fungi ◽  
Antibiotic Production ◽  
Morphological Characteristics ◽  
Colony Growth ◽  
Culture Conditions ◽  
Initial Ph

The biosynthesis of compounds with antibiotic activity produced by marine fungi, strongly depends on their growth conditions. A good understanding of the role of culture conditions in the biosynthesis of metabolites may lead to better exploitation of microbial metabolites. In this study, the influence of culture conditions including incubation period, initial pH and salinity on antimicrobial activity and secondary metabolites production of marine fungus 01NT.1.1.5 was investigated. This isolate, obtained from sponge Stylissa sp. in Nha Trang Bay, exhibited a broad spectrum of in vitro antimicrobial activity to Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 19111, Streptococcus faecalis ATCC 19433 and Candida albicans ATCC 10231. According to morphological characteristics and sequence analysis of 28S rDNA, the fungus was identified as Aspergillus flocculosus. The results indicated that antimicrobial activity and metabolite amount were highest when the fungus was cultivated in rice medium with incubation period of 20 days. The optimum salinity of 35 g/L and initial pH of 6.0 were found for the maximum antibiotic production. The colony growth, antimicrobial activity and production of secondary metabolites of the strain A. flocculosus 01NT.1.1.5 varied depending on salt concentrations and initial pH of medium. Particularly, extract of this fungus only showed activity against C. albicans when it was cultured in medium with 30-35 g/L salinity and initial pH 4.0-8.0. The results  indicate that salinity and initial pH along with cultivation period are important factors influencing antimicrobial activity and secondary metabolites of A. flocculosus 01NT.1.1.5, and might be for other marine fungi.

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