IN SITU MEASUREMENT OF DISSOLVED MATERIALS AS AN INDICATOR OF ORGANIC TERRAIN TYPE

1973 ◽  
Vol 53 (2) ◽  
pp. 231-236 ◽  
Author(s):  
M. E. WALMSLEY ◽  
L. M. LAVKULICH
Keyword(s):  
Ph Value ◽  
Environmental Parameters ◽  
Field Measurements ◽  
Oxygen Electrode ◽  
Natural Systems ◽  
Terrain Type ◽  
Ion Activity ◽  
Different Types ◽  
Dissolved Load

Portable equipment has been used to measure selected environmental parameters in situ. A battery-operated potentiometer used in conjunction with several specific ion electrodes, a platinum redox electrode, and a combination pH electrode were used to obtain ion activity, pH, and Eh measurements of natural systems. In addition, dissolved oxygen concentration was measured using an oxygen electrode and battery-operated meter. Results from the analysis of several streams are presented to illustrate the application of the technique to field measurements of streams as an indicator of environmental disturbance. Information collected also allowed for the differentiation of different types of organic terrain based on the dissolved load of the saturated organic materials. The terrain type referred to as fen had a higher activity of Na, Cl, and Ca, a higher pH value, and a lower concentration of oxygen than the bog terrain type. These results are explained with reference to organic terrain morphology and the distribution of permafrost in the study area.

Is buoyancy regulation in cyanobacteria an adaptation to exploit separation of light and nutrients?

1999 ◽  
Author(s):  
M. Bormans ◽  
B. S. Sherman ◽  
I. T. Webster
Keyword(s):  
Vertical Distribution ◽  
Field Measurements ◽  
Surface Mixed Layer ◽  
Natural Systems ◽  
Physical Mechanisms ◽  
Algal Abundance ◽  
Lateral Advection ◽  
Australian Freshwater ◽  
The Vertical Distribution

Fogg and Walsby’s (1971) hypothesis that buoyancy regulation in cyanobacteria might be an adaptation to exploit the separation of light and nutrients has since become a paradigm. The evidence of its veracity is examined within observations of algal abundance and chlorophyll distributions in several Australian freshwater systems and is also reviewed from the literature. It is clear from both laboratory experiments and field measurements that filamentous genera such as Anabaena and colony-forming genera such as Microcystis are capable of changing their buoyancy within a diurnal cycle. However, evidence for population migration to exploit separation of light and nutrient availability is tenuous, with most field observations of the vertical distribution of phytoplankton populations showing no evidence of vertical migration to sufficient depth to reach nutrients in stratified systems. Instead, changes in the vertical distribution of phytoplankton suggest a response either to the dynamics of the surface mixed layer or to lateral advection. In natural systems, algal buoyancy appears to be dependent much more on light than on nutrients, this being consistent with the carbohydrate ballast mechanism. Physical mechanisms can provide sufficient replenishment of epilimnetic nutrients to explain the observed net growth rates of phytoplankton populations in situ.

Pb Electrodeposition in the Presence of Chlorine Ions on Cu(100): An in Situ Optical Reflectivity Difference Study

2003 ◽  
Vol 781 ◽  
Author(s):  
J. Gray ◽  
W. Schwarzacher ◽  
X.D. Zhu
Keyword(s):  
Oblique Incidence ◽  
Opposite Sign ◽  
Bulk Phase ◽  
Phase Layer ◽  
Optical Reflectivity ◽  
Scan Rate ◽  
Different Types ◽  
Chlorine Ions ◽  
High Overpotentials

AbstractWe studied the initial stages of the electrodeposition of Pb in the presence of chlorine ions on Cu(100), using an oblique-incidence optical reflectivity difference (OIRD) technique. The OI-RD results reveal that immediately following the underpotential deposition (UPD) of the first Pb monolayer, two different types of bulk-phase films grow depending upon the magnitude of overpotential and cyclic voltammetry (CV) scan rate. At low overpotentials and/or slow scan rates, we propose that a bulk-phase Pb film grows on top of the UPD monolayer. At high overpotentials and/or fast scan rates, either a PbO, PbCl2, or a rough Pb bulk-phase layer grows on top of the UPD layer such that the reflectivity difference signal from such a film has an opposite sign.

scholarly journals Regression Analysis of Orthogonal, Cylindrical and Multivariable Color Parameters for Colorimetric Surface pH Measurement of Materials

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3682
Author(s):  
Katarína Vizárová ◽  
Izabela Vajová ◽  
Naďa Krivoňáková ◽  
Radko Tiňo ◽  
Zdenko Takáč ◽  
...  
Keyword(s):  
Ph Value ◽  
Critical Factor ◽  
Ph Measurement ◽  
Ph Indicator ◽  
Water Quality Control ◽  
Quality Management Systems ◽  
Surface Ph ◽  
Regression Parameters ◽  
Ph Detection

The surface pH is a critical factor in the quality and longevity of materials and products. Traditional fast colorimetric pH detection-based tests such as water quality control or pregnancy tests, when results are determined by the naked eye, cannot provide quantitative values. Using standard pH papers, paper-printed comparison charts, or colorimetric microfluidic paper-based analytical devices is not suitable for such technological applications and quality management systems (QMSs) where the particular tested material should contain a suitable indicator in situ, in its structure, either before or after the process, the technology or the apparatus that are being tested. This paper describes a method based on the combination of impregnation of a tested material with a pH indicator in situ, its exposure to a process of technology whose impact on pH value is to be tested, colorimetric pH measurement, and approximation of pH value using derived pH characteristic parameters (pH-CPs) based on CIE orthogonal and cylindrical color variables. The hypotheses were experimentally verified using the methyl red pH indicator, impregnating the acid lignin-containing paper, and preparing a calibration sample set with pH in the range 4 to 12 using controlled alkalization. Based on the performed measurements and statistical evaluation, it can be concluded that the best pH-CPs with the highest regression parameters for pH are √∆E, ln (a),√∆H (ab), a/L, h/b and ln (b/a). The experimental results show that the presented method allows a good estimation of pH detection of the material surfaces.

scholarly journals Underwater Holographic Sensor for Plankton Studies In Situ Including Accompanying Measurements

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4863
Author(s):  
Victor Dyomin ◽  
Alexandra Davydova ◽  
Igor Polovtsev ◽  
Alexey Olshukov ◽  
Nikolay Kirillov ◽  
...  
Keyword(s):  
World Ocean ◽  
Field Tests ◽  
Field Measurements ◽  
Measuring Systems ◽  
Water Turbidity ◽  
Background Data ◽  
Average Size ◽  
Size Dispersion

The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and interpreted, and their verification is carried out. The results of comparing the data on the concentration of individual taxa obtained using miniDHC with the data obtained by the traditional method using plankton catching with a net showed a difference of no more than 23%. The article also contains recommendations for expanding the potential of miniDHC, its purpose indicators, and improving metrological characteristics.

scholarly journals Selected In Situ Hybridization Methods: Principles and Application

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3874
Author(s):  
Dominika Veselinyová ◽  
Jana Mašlanková ◽  
Katarina Kalinová ◽  
Helena Mičková ◽  
Mária Mareková ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Imaging Techniques ◽  
Cell Communication ◽  
Probe Design ◽  
Rapid Progress ◽  
In Situ Techniques ◽  
Different Types ◽  
Laboratory Procedures ◽  
The Individual

We are experiencing rapid progress in all types of imaging techniques used in the detection of various numbers and types of mutation. In situ hybridization (ISH) is the primary technique for the discovery of mutation agents, which are presented in a variety of cells. The ability of DNA to complementary bind is one of the main principles in every method used in ISH. From the first use of in situ techniques, scientists paid attention to the improvement of the probe design and detection, to enhance the fluorescent signal intensity and inhibition of cross-hybrid presence. This article discusses the individual types and modifications, and is focused on explaining the principles and limitations of ISH division on different types of probes. The article describes a design of probes for individual types of in situ hybridization (ISH), as well as the gradual combination of several laboratory procedures to achieve the highest possible sensitivity and to prevent undesirable events accompanying hybridization. The article also informs about applications of the methodology, in practice and in research, to detect cell to cell communication and principles of gene silencing, process of oncogenesis, and many other unknown processes taking place in organisms at the DNA/RNA level.

scholarly journals Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie
Keyword(s):  
Hydraulic Conductivity ◽  
Field Measurements ◽  
Natural Soil ◽  
In Situ Tests ◽  
Seepage Analysis ◽  
Soil Deposits ◽  
Seepage Modeling ◽  
Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

scholarly journals Some indicators of water quality of the Tamis river

2011 ◽  
Vol 17 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Nada Babovic ◽  
Dejan Markovic ◽  
Vojkan Dimitrijevic ◽  
Dragan Markovic
Keyword(s):  
Water Quality ◽  
Ph Value ◽  
Ammonium Nitrogen ◽  
Field Analysis ◽  
Total Hardness ◽  
Chemical Parameters ◽  
Physico Chemical

This paper shows the results obtained in field analysis performed at the Tamis River, starting from the settlement Jasa Tomic - border between Serbia and Romania to Pancevo - confluence of Tamis into the Danube. The Tamis is a 359 km long river rising in the southern Carpathian Mountains. It flows through the Banat region and flows into the Danube near Pancevo. During the years the water quality of the river has severely deteriorated and badly affected the environment and the river ecosystem. In situ measurements enabled determination of physico-chemical parameters of water quality of the Tamis River on every 400 m of the watercourse, such as: water temperature, pH value, electrical conductivity, contents of dissolved oxygen and oxygen saturation. The main reason of higher pollution of Tamis is seen in connection to DTD hydro system. Sampling was performed at 7 points with regard to color, turbidity, total hardness, alkalinity, concentration of ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, iron, chlorides and sulphates in samples. The aim of the present work was to evaluate water quality in the Tamis River taking into account significant pollution, which originates from settlements, industry and agriculture, and to suggest appropriate preventive measures to further pollution decreasing of the river's water.

Enhanced coagulation with in situ manganese dioxide on removal of humic acid in micro-polluted water

2015 ◽  
Vol 72 (3) ◽  
pp. 406-414
Author(s):  
Yubin Zeng ◽  
Ziyang Zeng ◽  
Junlin Wang
Keyword(s):  
Humic Acid ◽  
Manganese Dioxide ◽  
Ph Value ◽  
Orthogonal Experiment ◽  
Surface Characteristics ◽  
Polluted Water ◽  
Enhanced Coagulation ◽  
Total Solids ◽  
Solids Content

The morphology and surface characteristics of manganese dioxide (MnO2) formed in situ, which was prepared through the oxidation of MnSO4 using KMnO4, were studied. The effects of factors including the form of MnO2, dosage, pH, dosing sequence of in situ MnO2 on the enhanced coagulation were systematically evaluated. The results of analysis by the UV254 and permanganate index CODMn methods indicated that humic acid removal increased from 9.2 and 2.5% to 55.0 and 38.9%, when 10 mg/L of the in situ MnO2 was added in the presence of 2 mg/L of polyaluminum sulfate. The studies of orthogonal experiment revealed that coagulation was most affected by the pH, whereas the dosage of in situ MnO2 and slow stirring duration exhibited a weaker effect. At a pH value of 4.0, in situ MnO2 dosage of 10 mg/L, slow stir over 40 min, and the total solids content was 20 mg/L, the humic acid removal by UV254 and CODMn methods reached 71.2 and 61.2%. These results indicated that the presence of in situ MnO2 enhanced the coagulation and removal of humic acid from water.

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