Large Scale Laboratory Tests for Calcium Carbonate Scaling in Sliding Sleeve Valves

2020 ◽  
Author(s):  
A. L. Martins ◽  
H. F .L. Santos ◽  
B. B. Castro ◽  
A. S. Gonçalves ◽  
D. A. Maffra ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Laboratory Tests ◽  
Large Scale

scholarly journals Evaluation of temporal, seasonal and geographic stability of the molluscicidal property of Euphorbia splendens latex

1992 ◽  
Vol 34 (3) ◽  
pp. 183-191 ◽  
Author(s):  
Virginia Torres Schall ◽  
Mauricio Carvalho de Vasconcellos ◽  
Ana Luiza Villaça-Coelho ◽  
Fátima Eliana Ferreira-Lopes ◽  
Ivonise Paz da Silva
Keyword(s):  
Aqueous Solutions ◽  
Laboratory Tests ◽  
Large Scale ◽  
Room Temperature ◽  
Tropical Climate ◽  
Wide Distribution ◽  
Promising Material ◽  
Active Principle ◽  
Reference Substance ◽  
Belo Horizonte

Laboratory tests with aqueous solutions of Euphorbia splendens var. hislopii latex have demonstrated seasonal stability of the molluscicidal principle, with LD90 values of 1.14 ppm (spring), 1.02 ppm (fall), 1.09 ppm (winter), and 1.07 ppm (summer) that have been determined against Biomphalaria tenagophila in the field. Assays on latex collected in Belo Horizonte and Recife yielded LD90 values similar to those obtained with the reference substance collected in Rio de Janeiro (Ilha do Governador), demonstrating geographic stability of the molluscicidal effect. The molluscicidal action of aqueous dilutions of the latex in natura, centrifuged (precipitate) and lyophilized, was stable for up to 124 days at room temperature (in natura) and for up to 736 days in a common refrigerator at 10 to 12ºC (lyophilized product). A 5.0 ppm solution is 100% lethal for snails up to 13 days after preparation, the effect being gradually lost to almost total inactivity by the 30th day. This observation indicated that the active principle is instable. These properties together with the wide distribution of the plant, its resistance and adaptation to the tropical climate, its easy cultivation and the easy obtention of latex and preparation of the molluscicidal solution, make this a promising material for large-scale use in the control of schistosomiasis

scholarly journals Effectiveness of Calcium Carbonate Whisker in Cementitious Composites

2020 ◽  
Author(s):  
Mingli Cao ◽  
Mehran Khan ◽  
Shakeel Ahmed
Keyword(s):  
Calcium Carbonate ◽  
Large Scale ◽  
Low Cost ◽  
Complex Structure ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Cementitious Composites ◽  
Toughening Mechanism ◽  
Micro Scale ◽  
Calcium Carbonate Whisker

Cementitious composites are porous material having complex structure system consist of hydration products, un-hydrated cement particles and pore solutions of various scales. Calcium carbonate whisker is a new type of low cost micro-scale filler fiber gaining popularity in the field of construction materials. However, addition of whisker has effect on physical, mechanical and microstructural characteristics of cementitious composites. Also, the low production cost of whisker will make the use of micro fiber more extensive in large scale construction projects. In this study, the effect of calcium carbonate whisker on physical, mechanical and microstructural properties of cementitious composites with different fiber contents are investigated. The fluidity, drying shrinkage, pore structure, impact resistance, compressive, flexural and splitting-tensile strength of whisker-mortar are considered. The scanning electron microscopy analysis is also performed to examine the microstructural and toughening mechanism of whisker reinforced composites. It was concluded that the addition of calcium carbonate whisker up to 10 % improves the physical and mechanical properties of cementitious composites and is suggested to be the optimize content. The calcium carbonate whisker also resists the crack propagation at micro scale and showed the toughening mechanism with better interfacial properties between whisker and matrix.

Large Scale Laboratory Tests of Dune Erosion

1991 ◽  
Author(s):  
M. F. Overton ◽  
J. S. Fisher ◽  
A. L. Stone
Keyword(s):  
Laboratory Tests ◽  
Large Scale ◽  
Dune Erosion

scholarly journals A Simple and Rapid Transformation of Golden Apple Snail (Pomacea canaliculata) Shells to Calcium Carbonate, Monocalcium and Tricalcium Phosphates

2019 ◽  
Vol 31 (11) ◽  
pp. 2522-2526
Author(s):  
S. Seesanong ◽  
C. Laosinwattana ◽  
K. Chaiseeda ◽  
B. Boonchom
Keyword(s):  
Calcium Carbonate ◽  
Tricalcium Phosphate ◽  
Large Scale ◽  
Low Cost ◽  
Pomacea Canaliculata ◽  
Scale Production ◽  
Apple Snail ◽  
Monocalcium Phosphate ◽  
X Ray ◽  
Golden Apple Snail

This study was designed to manage golden apple snail shells, the wastes created in large amount daily from the consumption of the meat of golden apple snail (Pomacea canaliculata) shells by transforming them to advanced compounds; calcium carbonate (CaCO3), monocalcium phosphate monohydrate [Ca(H2PO4)2·H2O], and tricalcium phosphate [Ca3(PO4)2]. They were successfully prepared by a rapid, simple, environmentally benign method using easily available and low-cost instrument. All synthesized samples were characterized by X-ray fluorescence, X-ray powder diffraction, FTIR spectroscopy and scanning electron microscopy to confirm the identities with the standard materials. The reproducibility and low-cost method suggest that it could be used in industry for a large-scale production of calcium carbonate, monocalcium phosphate monohydrate and tricalcium phosphate from golden apple snail shells as a replacement of natural mineral resources and be a good way to manage these shell wastes.

Efficacy of Chicken Pepsin as a Milk Clotting Enzyme1

1978 ◽  
Vol 41 (9) ◽  
pp. 684-688 ◽  
Author(s):  
S. GORDIN ◽  
I. ROSENTHAL
Keyword(s):  
Laboratory Tests ◽  
Large Scale ◽  
Scale Production ◽  
Milk Clotting ◽  
Large Scale Production

Comparative laboratory tests of cheesemaking show similarity between chicken pepsin and calf rennet. Suitability of chicken pepsin for large-scale production of Emmental (Swiss) and Kashkaval-type cheeses was tested.

Small and Large Scale Experimental Investigations of Wave Loads on a Slender Pile Within Closely Spaced Neighbouring Piles

2014 ◽  
Author(s):  
Lisham Bonakdar ◽  
Hocine Oumeraci
Keyword(s):  
Laboratory Tests ◽  
Large Scale ◽  
Model Tests ◽  
Scale Model ◽  
Research Centre ◽  
Experimental Investigations ◽  
Small Scale ◽  
Wave Loads ◽  
Large Wave ◽  
Wave Flume

Wave loads on a slender pile within a group of piles are studied by means of (i) large-scale laboratory tests carried out in the Large Wave Flume (GWK) of the Coastal Research Centre (FZK) in Hannover, and (ii) small scale experiments performed in 2 m-wide wave flume of Leichtweiss-Institute for Hydraulic Engineering and Water Resources (LWI), in Braunschweig, Germany. The small scale model tests (LWI) were scaled down (1:6.5) by Froude law from the large scale model tests (GWK). Scale and model effects are examined by comparing the results of small and large scale laboratory tests.

scholarly journals A Suggested Methodology for Assessing the Failure Risk of the Final Slopes of Former Open-Pits in Case of Flooding

2021 ◽  
Vol 13 (12) ◽  
pp. 6919
Author(s):  
Izabela-Maria Apostu ◽  
Maria Lazar ◽  
Florin Faur
Keyword(s):  
Ecological Restoration ◽  
Laboratory Tests ◽  
Large Scale ◽  
Negative Impact ◽  
Local Communities ◽  
Mining Activity ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mathematical Processing ◽  
Mining Works

Some valuable minerals, such as lignite, are extracted through open-pit mining works. After the cessation of mining activity, large-scale gaps result in the landscape. These gaps, also called “remaining gaps”, represent some of the roughest types of environmental impacts. After the cessation of mining activity, recovery and ecological restoration works are required. However, it is first necessary to carry out risk assessment studies considering the possible future influences on the final slopes. For this study, flooding of the remaining lignite open-pits gaps was considered as the ecological restoration option. The study was based on extensive research, including sampling, laboratory tests, statistical-mathematical processing, hypothesis formulation, evaluations, interpretations, and field observations, regarding the rock behavior and occurrence of negative geotechnical phenomena (geotechnical phenomena that have a negative impact and a risk on the integrity of the environment and local communities, such as landslides, rockfalls, liquefaction, suffosis) during the flooding process. This paper’s originality consists of combining the methods and methodologies developed with the help of classic methods (Fellenius, Janbu, and Bishop methods) and probabilistic ones (Rosenblueth method) existing in the specialized literature for solving the proposed problem and structuring the information similar to a guide.

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