scholarly journals The effect of ultrasound for algae growth control on zooplankton

2021 ◽  
pp. 1-9
Author(s):  
Pija Klemenčič ◽  
Aleksandra Krivograd Klemenčič
Keyword(s):  
Low Power ◽  
Growth Control ◽  
Algal Growth ◽  
Acute Effect ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Algae Growth ◽  
Scale Experiment ◽  
Natural Water Bodies

The use of ultrasound (US) to control algal growth in natural water bodies raises concern about the undesirable effects of US on non-target organisms. In this study a lab-scale experiment was performed to evaluate the effects of low-power US to counteract algal growth on adult and juvenile Daphnia magna. The 48-hour experiment was conducted in a 200 L glass aquarium with three fish nets, each filled with five D. magna. Each net was inspected for immobilized D. magna on different times during ultrasonication; additionally, basic physical-chemical parameters were measured. The results showed that tested low-power US device had no acute effect on the mobility of adult or juvenile D. magna, since after 48 h of ultrasonication 87% and 82% of adult and juvenile organisms remained mobile, with the same or higher percentage of mobile D. magna in the control groups. Additionally, no statistically significant effects were noticed on the measured physico-chemical parameters. However, when applied for algae control in field conditions, US is in operation constantly or at least for a long period of time (several weeks or months); therefore, the effect of long-term exposure to ultrasonication on zooplankton should be tested to ensure that US devices are safe for zooplankton.

scholarly journals Exploration of physico-chemical parameters and ionic constituents from groundwater used in irrigation of Tangail district, Bangladesh

2016 ◽  
Vol 3 (1) ◽  
pp. 115-119
Author(s):  
Elina Aziz ◽  
Md Younus Mia ◽  
Nowara Tamanna Meghla
Keyword(s):  
Trace Metal ◽  
Irrigation Water ◽  
Agricultural Crops ◽  
Soil Ecosystem ◽  
Long Term Effects ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Fe And Mn

The study was conducted for exploration of physico-chemical parameters and ionic constituents of groundwater used in irrigation of four upazilas namely Tangail Sadar, Kalihati, Delduar and Nagarpur upazila of Tangail district during the months of March, April and May of 2015. The physico-chemical parameters (pH, EC and TDS), ionic constituents (Ca2+, Mg2+, Na+, K+, Cl-, CO32-, HCO3-, PO43- and SO42-) and trace metal (Fe and Mn) were analyzed to assess the quality of irrigation in relation to soil properties and crop growth. The pH of groundwater indicates slightly alkaline in nature. As regards to EC the groundwater was in ‘good’ class and medium salinity hazards in quality for irrigation and the concentration of TDS indicates water as fresh water. The concentration of Ca2+, Mg2+, Na+, K+, Cl-, CO32-, HCO3-, PO43- and SO42- of groundwater were recorded within the permissible limit for irrigation and these ions might not create hazardous impact on soil ecosystem for growing crops. The trace amount of Fe and Mn was detected in irrigation water. In the study area, the groundwater was within the recommended limit and would not create problem for irrigation and that have not long term effects on irrigating agricultural crops which could be safely used for irrigation purposes.Res. Agric., Livest. Fish.3(1): 115-119, April 2016

Long-term corrosion of rebars embedded in aerial and hydraulic binders – Mechanisms and crucial physico-chemical parameters

2008 ◽  
Vol 50 (8) ◽  
pp. 2117-2123 ◽  
Author(s):  
Walter-John Chitty ◽  
Pascal Berger ◽  
Philippe Dillmann ◽  
Valérie L’Hostis
Keyword(s):  
Chemical Parameters ◽  
Physico Chemical

scholarly journals Hydrochemical Characterisation of Groundwater Quality: Merdja Plain (Tebessa Town, Algeria)

2020 ◽  
Vol 6 (2) ◽  
pp. 318-325 ◽  
Author(s):  
Baazi Houria ◽  
Kalla Mahdi ◽  
Tebbi Fatima Zohra
Keyword(s):  
Groundwater Quality ◽  
Principal Component ◽  
Anthropogenic Factors ◽  
Agricultural Activity ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
High Concentrations ◽  
Geological Formations

The objective of this work is to evaluate the physico-chemical quality of the groundwater of the Merdja plain and to determine the sources of mineralization. This quality is influenced by several environmental and anthropogenic factors such as geological context, climate, precipitation and interaction between groundwater and aquifers and human activities.  A Principal Component Analysis (PCA) on samples taken from several wells spread over the entire Tebessa plain (Merdja) allowed us to detect two axes that explain 73.4% of the information. The first axis describes the variables related to mineralisation and the second one describes those related to agricultural activity. Multidimensional Positioning (MDS) confirmed the interaction of physico-chemical parameters between them and their influence on groundwater quality by highlighting three groups of wells according to their physico-chemical characteristics, particularly those containing high concentrations of nitrates. This contamination is mainly the result of spreading the fertilisers and wastes that are dumped into the plain without treatment. Salinization is the result of long-term interactions between groundwater and geological formations.

PHYSICO-CHEMICAL PARAMETERS OF LONG-TERM STORAGE OF BEE`S HONEY

2020 ◽  
Vol 1 (5) ◽  
pp. 32-36
Author(s):  
L. N. Lazareva ◽  
◽  
L. I. Shtangret ◽  
J. V. Shapoval ◽  
O. S. Koval ◽  
...  
Keyword(s):  
Chemical Parameters ◽  
Long Term Storage ◽  
Physico Chemical ◽  
Term Storage

Проаналізовано 30 зразків меду бджолиного довготривалого зберігання (з 2009 по 2018 р.). Установлено, що діастазна активність меду падає. Так у 6 зразках меду діастазне число нижче ніж 10 од. Готе, ці зразки не відповідають вимогам державних стандартів. Виявлено, що при аналізі зразків меду бджолиного з 2009 по 2015 р. вміст гідроксиметилфурфуролу (ГМФ) був понад 25 мг/кг, що не відповідає вимогам ДСТУ. Зразки терміном зберігання з 2016 по 2018 р. відповідають за показниками якості меду першого ґатунку. Показано, що найбільше значення вмісту проліну відмічається у меді зразка № 11 2015 року – 773,0 мг/кг, а найнижчий показник вмісту проліну був у зразку № 25 2013 р. Електропровідність зразків меду тривалого зберігання становила від 0,128 до 0,524 мС/см, що відповідає вимогам щодо якості меду. Ключові слова: мед бджолиний, діастаза, ГМФ (гідроксиметилфурфурол), пролін, електропровідність.

scholarly journals Effects of long-term practices of different cropping systems on Physico-chemical parameters of soil quality

2020 ◽  
Vol 8 (2) ◽  
pp. 1136-1140
Author(s):  
Vivek Kumar ◽  
Sanjay Kumar Singh ◽  
Pankaj Singh ◽  
Sanjay Tiwari
Keyword(s):  
Soil Quality ◽  
Cropping Systems ◽  
Chemical Parameters ◽  
Physico Chemical

Comparative analysis of physico-chemical parameters of some river systems of Ebonyi State, Nigeria

2020 ◽  
Vol 34 (1) ◽  
pp. 33-41
Author(s):  
M.O. Nwabunike ◽  
G.V.C. Igwe ◽  
I.J. Ochokwu
Keyword(s):  
Natural Water ◽  
Control Experiment ◽  
Pond Water ◽  
Water Bodies ◽  
Fish Production ◽  
Chemical Parameters ◽  
Water Parameters ◽  
Physico Chemical ◽  
Water Fish ◽  
Natural Water Bodies

The study comparatively analyzed the general physico-chemical parameters of five different water bodies to assess their suitability for fish production. Four water bodies (Enyigba, Mkpuma, Ameka and Ebonyi) close to quarry sites were selected while the fifth was a culture pond water which served as the control experiment. The water parameters: pH, temperature, dissolved oxygen (DO), free CO2 and transparency were examined using standard methods for 24 months. The results showed that the pattern of temperature variation in all the water bodies examined followed a similar trend with the lowest value observed between December and January. The pond water showed slightly varied pH levels compared to the natural water bodies. The DO contents of Ebonyi, Mkpuma and Enyigba were higher than those recorded from Ameke and pond. Relatively, lower concentrations of free CO2 were recorded in the pond water and Ebonyi river during the harmattan period (December to January) and below the detectable levels. The variation of Sechi disc depth was higher in Enyigba when compared with other water bodies all through the period of the experiment. The trend of transparency was the same in all the water bodies. Keywords: Physico-chemical parameters, natural water bodies, pond water, fish production, Ebonyi State

Long-term monitoring of the Dead Sea level and brine physico-chemical parameters “from 1987 to 2008”

2010 ◽  
Vol 81 (3) ◽  
pp. 207-212 ◽  
Author(s):  
Abdelaziz Khlaifat ◽  
Michael Hogan ◽  
Gary Phillips ◽  
Khalid Nawayseh ◽  
Jamal Amira ◽  
...  
Keyword(s):  
Sea Level ◽  
Dead Sea ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Long Term Monitoring ◽  
The Dead ◽  
Term Monitoring

MODEL FOR PREDICTION OF HIGH TEMPERATURE DURABILITY OF CASTABLE NICKEL-BASE SUPERALLOYS

2021 ◽  
pp. 16-31
Author(s):  
N.V. Petrushin ◽  
◽  
Е.S. Elyutin ◽  
Keyword(s):  
Structural Phase ◽  
Atomic Mass ◽  
Term Strength ◽  
Chemical Parameters ◽  
Polycrystalline Nickel ◽  
Physico Chemical ◽  
Durability Prediction ◽  
Nickel Base ◽  
The Relationship

The relationship between the long-term strength and the structural-phase and physico-chemical parameters of castable polycrystalline nickel-based superalloys is considered. A regression model for prediction of the durability at a temperature of 1100 °C and a stress of 80 MPa of the considered class of alloys is proposed. The model takes into account the amount of the γ'-phase, the γ'-solvus and solidus temperatures, γ/γ'-misfit, the lattice spacing of the γ- and γ'-phases, and the atomic mass of the alloy. The reliability of the durability prediction is confirmed by comparison with the experimental results on the long-term strength at temperatures 1000, 1050 and 1100 °C of a number of industrial and experimental castable polycrystalline nickel-based superalloys.

scholarly journals The Unusual Reddish-Bloom Appearance in a Freshwater Fishpond at Kingolwira National Fish Farming Center, Morogoro, Tanzania

2020 ◽  
Vol 9 (2) ◽  
pp. 204-216
Author(s):  
Offoro N. Kimambo ◽  
Jabulani R. Gumbo ◽  
Titus A.M Msagati ◽  
Hector Chikoore
Keyword(s):  
Fish Farming ◽  
Test Statistics ◽  
Chemical Parameters ◽  
Future Studies ◽  
Physico Chemical ◽  
Long Term Monitoring ◽  
The Difference ◽  
Term Monitoring ◽  
Time Assessment

The study aimed to examines a case of what constituted the uncommonly reddish-bloom appearance in the fishponds during the dry season (September 2018) at Kingolwira National Fish Farming Center located in Morogoro, Tanzania. The study used a benchtop FlowCAM® to investigate species' morphology. One-time assessment of physico-chemical characteristics during the event was performed from the reddish and non-reddish fishponds. Images were compared with the available literature, but also t-test statistics were performed to examine the difference between the fishponds. The results show that the fishponds were significantly (p<0.05) different from each other in terms of physico-chemical parameters except for water temperatures. Furthermore, Microcystis species dominated the non-reddish fishpond whereas Euglenophytes species were pervasive in the reddish fishpond. The two species have the potential to produce secondary metabolites (toxins) or to produce a hypoxia condition that is harmful to the fishery, aquatic ecology, and human. To confirm toxicity nature and dynamics further,  future studies should consider extensive and regular diurnal and long-term monitoring.

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