scholarly journals Testing of pilot 2 m3 exposure chamber for formation of brochantite based patina on copper and copper alloys – objects of practical dimensions

2020 ◽  
Vol 64 (3) ◽  
pp. 95-99
Author(s):  
R. Bureš ◽  
P. Rak ◽  
J. Stoulil
Keyword(s):  
Water Samples ◽  
Ph Value ◽  
Copper Alloys ◽  
Exposure Chamber ◽  
Stable Phase ◽  
Atmospheric Conditions ◽  
Water Colour

Abstract Formation of natural patina on copper and copper alloys objects takes tens of years. There are solutions for patination, which are used in restorers’ practice. However, these artificial patinas are usually based on nitrates, carbonates or chlorides. Patina based on brochantite is the most stable phase under atmospheric conditions. This type of patina was successfully formed in laboratory in a small exposure chamber with higher content of SO2. This work is next step of the experiment to make this method become more practicable. It started with construction 2 m3 exposure chamber and simulation of ideal conditions for patination process. The length of drying phase, homogeneity of conditions, pH of feeding water, colour of patina, placement of samples and final appearance were observed. The chamber construction allows to achieve ideal pH value of feeding water, samples surface became dry during the ventilation and temperature during condensation was stable at 40 °C. These conditions are ideal for patination process.

Status of Heavy Metal Contaminations of Lake Water of Dhaka Metropolitan City

2013 ◽  
Vol 5 (2) ◽  
pp. 345-348 ◽  
Author(s):  
MAA Mokaddes ◽  
BS Nahar ◽  
MA Baten
Keyword(s):  
Water Pollution ◽  
Heavy Metal ◽  
Chemical Analysis ◽  
Natural Resources ◽  
Lake Water ◽  
Water Samples ◽  
Ph Value ◽  
Central Laboratory ◽  
Metropolitan City

A study was conducted to evaluate level of water pollution and its influence on heavy metal contaminations of lake water of Dhaka metropolitan city. The water samples were collected from lakes of Dhaka metropolitan city during February to March, 2008. The chemical analysis of water samples included pH, EC, As, Cu, Mn, 'ln. Pb and Cd. Analysis of lake water samples was done at the Central Laboratory of Bangladesh Agricultural University, Mymensingh. The concentrations of heavy metal of lake water were recorded as: in case of pH = 6.95, in case of EC = 22.44 (?scm-1), in case of Cu = 0.018 ppm, in case of Zn = 0.274 ppm, in case of Mn = 0.084 ppm, in case of As = 0.002 ppb, in case of Pb = 0.002 ppm and in case of Cd = 0.044 ppm. The pH value of lakes water range from 5.34 to 7.68, an indication of slightly acidic to alkaline in nature. The average EC value for lakes water ranged from 17.61 to 34.61 ?Scm-1 where EC value varied from 14.24 to 33.48 ?Scm-1 in the lake water.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14841 J. Environ. Sci. & Natural Resources, 5(2): 345-348 2012

scholarly journals Quantitative assessment of ionic status of pond water for irrigation and aquaculture usage in the selected sites of Mymensingh areas, Bangladesh

2019 ◽  
Vol 6 (2) ◽  
pp. 301-313
Author(s):  
Taslima Akter ◽  
Shampa Rani Ghosh ◽  
Sitesh Chandra Sarker ◽  
Md Mokhlesur Rahman ◽  
KM Eadun Nabi
Keyword(s):  
Water Samples ◽  
Quantitative Assessment ◽  
Ph Value ◽  
Pond Water ◽  
The Other ◽  
Acceptable Limit ◽  
Legal Limit ◽  
Other Hand ◽  
Agricultural Chemistry ◽  
Inorganic Components

Ponds are considered to be self-contained, land lock ecosystem which is often teeming with rich vegetation and diverse organismal life. The pond water contains different organic and inorganic components. The experiment was carried out in laboratory, Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh through collection of pond water from Gouripur and Muktagacha under Mymensingh division for assessment of major ionic status and suitability parameters for irrigation and aquaculture usage in quantitative way. Around 30 samples were collected from different location. On the basis of HCO3 ion, all water samples except 3 samples were not suitable for irrigation because this anion exceeded the acceptable limit (1.5 meL-1). On the other hand, HCO3 ion was not treated as problematic in all samples except 2 samples for aquaculture usages. The concentrations of Ca, Mg, Na, K, PO4 and SO4 were far below the recommended limit. Considering aquaculture usage, Cl ion was considered as hazardous in all the pond water samples because this anion was above the legal limit (<0.003mgL-1). pH value of pond ranged from 7.02 to 7.87 indicating alkaline in nature and were not problematic for irrigation and aquaculture usage. Among the major ionic constituents, the remarkable significant correlations existed between Ca vs Mg, Ca vs K, Mg vs SO4, K vs Na, Na vs SO4. Res. Agric., Livest. Fish.6(2): 301-313, August 2019

Preparation and Targeted Regulation of Microbial Induced Mineralized Products

2020 ◽  
Vol 12 (1) ◽  
pp. 116-123
Author(s):  
Haihe Yi ◽  
Qiwei Zhan ◽  
Chunxiang Qian
Keyword(s):  
Ph Value ◽  
Cementitious Materials ◽  
Stable Phase ◽  
Logarithmic Phase ◽  
Culture Solution ◽  
Extracellular Production ◽  
X Ray Diffraction ◽  
X Ray ◽  
Culture Process ◽  
Growth And Reproduction

Microbial induced mineralization is an effective method to prepare green cementitious materials, which has the characteristics of ecological and environmental protection. In this study, preparation and targeting regulation of mineralized products by Bacillus lysine induced was investigated. Law of growth and reproduction was studied via change curves of concentration and pH value of culture solution in the culture process. Four periods, included retardation phase, logarithmic phase, stable phase and decline phase, were verified. The pH value of culture solution was on the rise throughout the culture process, which increased from 7 to 8.1. Characteristics of enzyme production were explored by the deposition of mineralized products in different systems, and the way of extracellular production enzyme was determined. The composition and microstructure of mineralized products were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray spectroscopy (EDS). The mineralized products were characterized as calcite, and mineralized products in the culture solution had higher crystallinity. Finally, targeting regulation of temperature on mineralized products was conducted. At the low temperature, mineralization efficiency was higher, and the structure of mineralized products was more favorable.

Influence of Temperature and Wavelength on Optical Behavior of Copper Alloys

2014 ◽  
Vol 655 ◽  
pp. 89-94 ◽  
Author(s):  
Vincent Mann ◽  
Florian Hugger ◽  
Stephan Roth ◽  
Michael Schmidt
Keyword(s):  
Laser Light ◽  
Copper Alloys ◽  
Laser Beam Welding ◽  
Inert Gases ◽  
Heating Process ◽  
Atmospheric Conditions ◽  
Temperature Dependent ◽  
Dependent Absorption ◽  
Welding Processes ◽  
Optical Behavior

Quantitative measured values for absorption of copper and its alloys are jet unknown in the temperature range between 30 °C and 500 °C which has to be passed before material melts in the initial phase of laser beam welding. Thus this paper investigates temperature and wavelength dependent absorption for VIS and IR wavelengths. For this purpose specimens of copper and copper alloys are heated up and reflected laser light from the surface is measured by using an Ulbricht sphere in combination with a photodiode. During welding processes inert gases are in use to reduce oxidation. Hence the influence of shielding gases on the absorption will also be taken into account during the heating process of the specimens. Consequently this paper provides results for the temperature dependent absorption of copper and copper alloys for different wavelengths at atmospheric conditions and argon shielding.

scholarly journals Determination of Surface Water Quality for Irrigation in Dinajpur

2021 ◽  
Vol 9 (10) ◽  
pp. 1782-1791
Author(s):  
Md. Motaharul Islam ◽  
Mst. Taslema Nasrin ◽  
Md. Mofizul Islam
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Surface Water ◽  
Water Samples ◽  
Crop Production ◽  
Ph Value ◽  
Surface Water Quality ◽  
Total Dissolved Solids ◽  
Almost All

A research was carried out to assess the suitability of surface water for irrigation purposes. For this reason, 56 samples of surface water were collected from each union of Dinajpur sadar upazilla, Dinajpur. The analysis was included pH, EC, TDS, Ca, Mg, S, P, Na, K, Cl- and HCO3- to evaluate the suitability of surface water for irrigation purposes. Almost all the water samples were within the recommended pH value for irrigation and a great impact on crop production. With respect to electrical conductivity (EC) samples were low to medium salinity. For total dissolved solids (TDS), all samples were considered as freshwater for irrigation. On the basis of Ca, Mg, S, P, Na, K, Cl- and HCO3- all samples could safely be used for irrigation and would not affect the soils.

scholarly journals Physicochemical and Microbial Evaluation of Selected Residential Borehole Water Samples in Awka, Anambra State, Nigeria

2020 ◽  
pp. 132-139
Author(s):  
Victor Henry Azubuike Enemor ◽  
Precious Ebuka Okeke ◽  
Uchechukwu Chibuzo Ogbodo
Keyword(s):  
Water Samples ◽  
Ph Value ◽  
Enterobacter Aerogenes ◽  
Physicochemical Analysis ◽  
Total Hardness ◽  
Human Consumption ◽  
Residential Areas ◽  
Anambra State ◽  
Hygiene Practices ◽  
Borehole Water

Water is very important to the existence of humans though could also serve as vehicle for pathogenic organisms and dangerous organic and inorganic matters. The physicochemical and microbial analyses of selected borehole water samples in Awka residential areas were conducted with the aim of ascertaining suitability or otherwise for human consumption. The total hardness, pH, alkalinity, some common elements and presence of toxic metals were determined by standard methods of American Public Health Association. The presence of microorganisms in the water samples was also determined. Results of the physicochemical analysis of the borehole water samples showed a mean pH value of 5.52 below the WHO standard of 6.5 - 8.5 and mean total hardness of 150 ppm greater than the WHO standard of 70 ppm. The microelements such as manganese, zinc, lead, selenium, nickel and cadmium were found to be below detectable levels in the water samples. Five bacteria species were isolated and identified in the water samples as Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli and Klebsiella pneumoniae. The physicochemical properties and the bacteria load of most of the water samples indicate that they were unfit for human consumption as the samples were outside WHO reference standard for potable water suggesting a need for increased awareness for improved sanitation and hygiene practices in the state.

scholarly journals Assessment of Groundwater Quality in Parts of Ijoko Area, Sango-Otta Axis of Southwestern Nigeria

2019 ◽  
pp. 103-111
Author(s):  
Victoria Abiola Dairo ◽  
Victor Oludare Fagoyinbo ◽  
Godson Mac-tyger
Keyword(s):  
Electrical Conductivity ◽  
Drinking Water ◽  
Water Samples ◽  
Ph Value ◽  
High Concentration ◽  
Southwestern Nigeria ◽  
Major Cations ◽  
Physico Chemical ◽  
Irrigation Purpose ◽  
Total Dissolved Solid

A total of 26 water samples comprising of well, river and borehole waters were subjected to physico-chemical tests to evaluate its quality. The result of the physical characteristics shows that the average pH value, total dissolved solid and electrical conductivity is 4.9, 1027.31mg/L and 1526.92mg/L respectively. Thus, relatively above the desirable limit for drinking water while the ionic dominance of the major cations and anions reveal high concentration of Na+ and Cl- amidst other ions in the order of Na+>Ca2+>Mg2+> K+ and Cl->HCO3- > SO42- respectively wherein the water was classified as belonging to Na-Cl facies and unsuitable for irrigation purpose.

scholarly journals DELINEATION OF CONCENTRATION OF FERRUGINOUS MINERALS IN AQUIFERS IN YENAGOA, BAYELSA STATE, NIGERIA, USING GEOELECTRIC VERTICAL ELECTRICAL SOUNDING (VES) AND PHYSICOCHEMICAL TECHNIQUES

2020 ◽  
Vol 4 (2) ◽  
pp. 90-101
Author(s):  
Okorobia E. Mark ◽  
Etim D. Uko ◽  
Amechi Bright ◽  
Onengiyeofori A. Davies
Keyword(s):  
Water Samples ◽  
Ph Value ◽  
Physicochemical Analysis ◽  
Vertical Electrical Sounding ◽  
World Health ◽  
Physical Parameters ◽  
Chemical Parameters ◽  
Flame Atomic Absorption ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Electrical Sounding

A total of sixteen Vertical Electrical Sounding (VES) surveys and five physicochemical analyses were carried out in selected locations within the Yenagoa Metropolis, in Bayelsa State, Nigeria, to delineate the concentration of ferruginous minerals in freshwater aquifers in the area. For the geophysical survey, the Schlumberger electrode configuration was employed. The resulting data obtained was processed and interpreted using Excel suite, IPI2WIN resistivity, Surfer-11 and Rockworks software. The results revealed four to six geologic layers across the area, and were used to generate geoelectric maps which showed that in most part of the study area, there were uneven distributions of shallow aquifers (4 – 10m), and uneven layers of clay and sandy-silt at varying depths up to 20m. The physicochemical analysis of raw water samples collected from five boreholes located in close proximity to the VES sounding locations were analysed for physical and chemical parameters. Physical parameters tested include colour, conductivity, turbidity, and temperature. Chemical parameters analysed are pH, Dissolved Oxygen (DO), Total Dissolved Solids (TDS) Alkalinity, Total Iron, Carbonate, Chloride, Sulphate, and heavy metals such as copper, chromium, nickel, cadmium, manganese, zinc and lead. The pH was determined using a Mettler Toledo (GmbH 8603 Schwerzenbach) pH meter by direct measurement. An analogue mercury thermometer was used for temperature measurements and a Hach 2100A turbidimeter for turbidity determination. Also, the concentrations of Zinc, Lead, and Copper in the water samples were obtained using the flame atomic absorption spectrophotometer. It was observed that the values SO42- , Cl-, Na2+, Mg2+, Ca2+, F- have values below World Health Organization (WHO) standard in all boreholes tested while Mn2+, NH3, PO3−and Fe2+, K+, and Cu2+ have values above WHO standard in some boreholes. The pH values all showed that the water was slightly basic as the values all exceeded the neutral limit 7, with only station showing slightly elevated pH value 9, suggesting the presence of iron bacteria. F-, K+, Fe2+ and Mn2+ have values that exceeded the WHO standard. The results from Physicochemical and geophysical analysis suggest that at depths of 20 – 45m, the concentration of ferruginous minerals is high especially towards the north eastern section of the study area and so drilling should be made to approximate depths of 50 – 80m for minimal iron contamination in the aquifers.

Exposure chamber for animals at changed atmospheric conditions

1963 ◽  
Vol 18 (5) ◽  
pp. 1035-1037
Author(s):  
P. Gans
Keyword(s):  
Carbon Dioxide ◽  
High Oxygen ◽  
Continuous Treatment ◽  
Exposure Chamber ◽  
Atmospheric Conditions ◽  
High Carbon ◽  
Oxygen Exposure ◽  
Oxygen Percentage ◽  
Animal Exposure ◽  
High Carbon Dioxide

An airtight exposure chamber is described in which mice can be kept continuously in an atmosphere with a high carbon dioxide percentage, or with a low or high oxygen percentage. Advantages of the apparatus described are the absence of moving parts inside the chamber and, in the experiments with a low or high percentage of oxygen, the absorption of carbon dioxide and water outside the chamber, permitting the continuous treatment of the animals. animal exposure chamber; carbon dioxide exposure; oxygen exposure Submitted on January 4, 1963

scholarly journals Quantification and distribution of vibrio species in water from an estuary in Ceará-Brazil impacted by shrimp farming

2010 ◽  
Vol 58 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Renata A Costa ◽  
Giselle C Silva ◽  
Jackson R. O Peixoto ◽  
Gustavo H. F Vieira ◽  
Regine H. S. F Vieira
Keyword(s):  
Environmental Factor ◽  
Water Samples ◽  
Ph Value ◽  
Vibrio Species ◽  
Shrimp Farming ◽  
Northeastern Brazil ◽  
Most Probable Number ◽  
Probable Number ◽  
Isolated Species

Vibrios were quantified and their distribution determined for the estuary of the Coreaú river, in Northeastern Brazil, based on 24 water samples collected between June and October 2005. The most probable number of vibrios per 100 mL ranged from 230 x 10³ to 240 x 10(11). The pH value was the environmental factor most strongly associated with the abundance of vibrios. Sixty-two vibrio strains were isolated belonging to 15 species (6 of which observed in June-September and 8 in October). The most frequently isolated species were V. parahaemolyticus and V. cholerae.

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