scholarly journals Magnetic Pollution of Soil Samples at Some Industrial Sites in Jos Metropolis, Plateau State, Nigeria

2020 ◽  
Vol 24 (2) ◽  
pp. 193-196
Author(s):  
E.S. Akanbi ◽  
E.J. Nasamu
Keyword(s):  
Magnetic Susceptibility ◽  
Low Frequency ◽  
Magnetic Behaviour ◽  
Soil Samples ◽  
Anthropogenic Sources ◽  
General View ◽  
Industrial Sites ◽  
Plateau State ◽  
The Relationship ◽  
Specific Susceptibility

Magnetic susceptibility of polluted material can give a general view of the degree of heavy metal pollution, prior to a more expensive and time- consuming chemical analyses. In this study, magnetic susceptibility measurements of 40 soil samples collected from some industrial sites of Jos  Metropolis, were made using MS2G Sensor connected to Bartington MS 2 susceptibility meter. Volume magnetic susceptibility values ranged from  0.00026 x 10-5 SI to 0.0650 x 10-5 SI while low frequency mass specific susceptibility values ranged from 0.1181 x 10-6 m3kg-1 to 20.3 x 10- 6 m3kg-1. In both cases least and highest values are recorded at Zuma Steel and Dilimi respectively. Comparing low frequency mass specific susceptibility  values obtained from industrial sites to that obtained from non-industrial sites, it was observed that samples 11 and 12 from JIB and all samples collected from Dilimi recorded values higher than the  background soil samples thus indicating magnetic enhancement of soil at these locations by anthropogenic sources. The relationship between the volume magnetic susceptibility and mass specific susceptibility showed correlation of 0.983 implying that volume magnetic susceptibility results can be accepted in the absence of low frequency mass specific susceptibility measurement to assess magnetic pollution. The study also revealed that the magnetic behaviour of the dried soil samples collected from the industrial sites are controlled by concentration of ferrimagnetic minerals. Keywords: Magnetic, Pollution, Ferrimagnetic, Susceptibility, Anthropogenic, Dilimi

Magnetic and Soil Parameters as a Potential Indicator of Soil Pollution

2021 ◽  
Author(s):  
Mohammed Murthuza ◽  
Surumbar Kuzhali ◽  
Lakshmi Narasimhan ◽  
.Thirukumaran V ◽  
Chandrasekaran A ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
High Frequency ◽  
Tamil Nadu ◽  
Pearson Correlation ◽  
Chemical Properties ◽  
Soil Samples ◽  
Anthropogenic Sources ◽  
Soil Parameters ◽  
Contamination Level ◽  
High Concentration

Abstract The aim of this study was to look into the effect of land use or human activity on soil samples and to distinguish between pollution from anthropogenic sources or natural sources using magnetic susceptibility and statistical method. In soil samples from Tiruvannamalai Dist, Tamilnadu, magnetic susceptibility measurements at low frequency (lf) and high frequency (hf) were carried out. The physic-chemical properties such as % of sand, silt, clay, Electrical conductivity (EC) and pH in soil samples were determined using the standard methods. This research involves the identification of ferrimagntic minerals in soil samples from various locations in Tiruvannamalai, Tamil Nadu, using frequency-dependent susceptibility. The mean value of low and high frequency magnetic susceptibility are found to be 273.39 ×10-8m3 kg-1 and 270.51×10-8m3kg-1 respectively. In some locations, the magnetic enhancement value suggests a high concentration of ferrimagntic minerals in the soil. Multivariate statistical analysis, such as factor analysis (FA), Pearson correlation (PC), and cluster analysis (CA), is used to determine the role of physic-chemical parameters on magnetic susceptibilities and to assess the contamination level of soil samples. This analysis revealed that magnetic susceptibility can be used as a proxy for determining the level of contamination in the soil.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.

K-MEANS CLUSTERING ALGORITHM BASED CLASSIFICATION OF SOIL FERTILITY IN NORTH WEST NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 780-787
Author(s):  
Ibrahim Hassan Hayatu ◽  
Abdullahi Mohammed ◽  
Barroon Ahmad Isma’eel ◽  
Sahabi Yusuf Ali
Keyword(s):  
Soil Fertility ◽  
Crop Yield ◽  
Clustering Algorithm ◽  
Soil Samples ◽  
North West ◽  
R Programming ◽  
Available Information ◽  
Northwest Region ◽  
The Relationship

Soil fertility determines a plant's development process that guarantees food sufficiency and the security of lives and properties through bumper harvests. The fertility of soil varies according to regions, thereby determining the type of crops to be planted. However, there is no repository or any source of information about the fertility of the soil in any region in Nigeria especially the Northwest of the country. The only available information is soil samples with their attributes which gives little or no information to the average farmer. This has affected crop yield in all the regions, more particularly the Northwest region, thus resulting in lower food production.  Therefore, this study is aimed at classifying soil data based on their fertility in the Northwest region of Nigeria using R programming. Data were obtained from the department of soil science from Ahmadu Bello University, Zaria. The data contain 400 soil samples containing 13 attributes. The relationship between soil attributes was observed based on the data. K-means clustering algorithm was employed in analyzing soil fertility clusters. Four clusters were identified with cluster 1 having the highest fertility, followed by 2 and the fertility decreases with an increasing number of clusters. The identification of the most fertile clusters will guide farmers on where best to concentrate on when planting their crops in order to improve productivity and crop yield.

scholarly journals Slithering CSF: Cerebrospinal Fluid Dynamics in the Stationary and Moving Viper Boa, Candoia aspera

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 672
Author(s):  
Bruce A. Young ◽  
Skye Greer ◽  
Michael Cramberg
Keyword(s):  
Cerebrospinal Fluid ◽  
Cardiac Cycle ◽  
Low Frequency ◽  
Mean Amplitude ◽  
The Body ◽  
Body Waves ◽  
Lower Amplitude ◽  
Lateral Undulation ◽  
Recovery From Anesthesia ◽  
The Relationship

In the viper boa (Candoia aspera), the cerebrospinal fluid (CSF) shows two stable overlapping patterns of pulsations: low-frequency (0.08 Hz) pulses with a mean amplitude of 4.1 mmHg that correspond to the ventilatory cycle, and higher-frequency (0.66 Hz) pulses with a mean amplitude of 1.2 mmHg that correspond to the cardiac cycle. Manual oscillations of anesthetized C. aspera induced propagating sinusoidal body waves. These waves resulted in a different pattern of CSF pulsations with frequencies corresponding to the displacement frequency of the body and with amplitudes greater than those of the cardiac or ventilatory cycles. After recovery from anesthesia, the snakes moved independently using lateral undulation and concertina locomotion. The episodes of lateral undulation produced similar influences on the CSF pressure as were observed during the manual oscillations, though the induced CSF pulsations were of lower amplitude during lateral undulation. No impact on the CSF was found while C. aspera was performing concertina locomotion. The relationship between the propagation of the body and the CSF pulsations suggests that the body movements produce an impulse on the spinal CSF.

scholarly journals Impacts of oak deforestation and rainfed cultivation on soil redistribution processes across hillslopes using 137Cs techniques

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shamsollah Ayoubi ◽  
Nafiseh Sadeghi ◽  
Farideh Abbaszadeh Afshar ◽  
Mohammad Reza Abdi ◽  
Mojtaba Zeraatpisheh ◽  
...  
Keyword(s):  
Land Use ◽  
Magnetic Susceptibility ◽  
Soil Erosion ◽  
Erosion Rate ◽  
Land Use Changes ◽  
Soil Samples ◽  
Natural Forest ◽  
Oak Forests ◽  
Erosion Rates ◽  
Rainfed Farming

Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes. To achieve this goal, we select a representative area in the Lordegan district, central Iran. 137Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming. In each hillslope, soil samples from three depths (0–10, 10–20, and 20–50 cm) and in four different slope positions (summit, shoulder, backslope, and footslope) were taken in three transects of about 20 m away from each other. The activity of 137Cs was determined in all the soil samples (72 soil samples) by a gamma spectrometer. In addition, some physicochemical properties and the magnetic susceptibility (MS) of soil samples were measured. Results Erosion rates reached 51.1 t·ha− 1·yr− 1 in rainfed farming, whereas in the natural forest, the erosion rate was 9.3 t·ha− 1·yr− 1. Magnetic susceptibility was considerably lower in the cultivated land (χhf = 43.5 × 10− 8 m3·kg− 1) than in the natural forest (χhf = 55.1 × 10− 8 m3·kg− 1). The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one, compared to that in the rainfed farming land. The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming, respectively. Conclusions We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area. Moreover, land management can influence soil erosion intensity and may both mitigate and amplify soil loss.

scholarly journals On the Relationship between Regional Ocean Heat Content and Sea Surface Height

2017 ◽  
Vol 30 (22) ◽  
pp. 9195-9211 ◽  
Author(s):  
John T. Fasullo ◽  
Peter R. Gent
Keyword(s):  
Time Scales ◽  
Low Frequency ◽  
Heat Content ◽  
Sea Surface Height ◽  
Ocean Heat Content ◽  
Ocean Dynamics ◽  
Sea Surface ◽  
Altimeter Data ◽  
Model Control ◽  
The Relationship

Abstract An accurate diagnosis of ocean heat content (OHC) is essential for interpreting climate variability and change, as evidenced for example by the broad range of hypotheses that exists for explaining the recent hiatus in global mean surface warming. Potential insights are explored here by examining relationships between OHC and sea surface height (SSH) in observations and two recently available large ensembles of climate model simulations from the mid-twentieth century to 2100. It is found that in decadal-length observations and a model control simulation with constant forcing, strong ties between OHC and SSH exist, with little temporal or spatial complexity. Agreement is particularly strong on monthly to interannual time scales. In contrast, in forced transient warming simulations, important dependencies in the relationship exist as a function of region and time scale. Near Antarctica, low-frequency SSH variability is driven mainly by changes in the circumpolar current associated with intensified surface winds, leading to correlations between OHC and SSH that are weak and sometimes negative. In subtropical regions, and near other coastal boundaries, negative correlations are also evident on long time scales and are associated with the accumulated effects of changes in the water cycle and ocean dynamics that underlie complexity in the OHC relationship to SSH. Low-frequency variability in observations is found to exhibit similar negative correlations. Combined with altimeter data, these results provide evidence that SSH increases in the Indian and western Pacific Oceans during the hiatus are suggestive of substantial OHC increases. Methods for developing the applicability of altimetry as a constraint on OHC more generally are also discussed.

MAGNETIC BEHAVIOUR OF UPdAl, UCuGa AND UCuSn

1993 ◽  
Vol 07 (01n03) ◽  
pp. 850-854 ◽  
Author(s):  
V.H. TRAN ◽  
R. TROĆ
Keyword(s):  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Low Temperatures ◽  
Magnetic Behaviour ◽  
Type Structure ◽  
Complex Structures ◽  
Temperature Dependent ◽  
Antiferromagnetic Ordering

Magnetic susceptibility and electrical resistivity have been measured on UCuGa, UCu1+xSn1−x, (x=0 and 0.1), and UPdAl. The first two compounds, crystallizing in the hexagonal CaIn2-type structure, show at low temperatures an antiferromagnetic ordering probably with complex structures. UPdAl, which adopts the orthorhombic TiNiSi-type structure, was found to be a weakly temperature-dependent paramagnet down to 4.2 K.

NEW ETIOLOGICAL FACTORS OF OCCUPATIONAL HEARING LOSS

2021 ◽  
Author(s):  
V.B. Pankova ◽  
◽  
М.F. Vilk ◽  
◽  
◽  
...  
Keyword(s):  
Hearing Loss ◽  
Low Frequency ◽  
Evidence Base ◽  
Frequency Noise ◽  
Labor Intensity ◽  
Etiological Factors ◽  
Hearing Organ ◽  
The Relationship ◽  
Vascular Stria ◽  
Occupational Hearing Loss

Annotation. On the example of railway and air transport, a number of new issues of occupational hearing loss are shown, requiring study and subsequent implementation in practical health care, as new etiological factors in the development of hearing loss. This concerns the factor of labor intensity, which has a potentiating, pathogenetic significance, along with noise, in the development of hearing loss due to the formation of chronic stress, leading to additional ischemia of the vascular stria and damage to the neuroepithelium of the inner ear. There is a need, along with the development of a methodology for assessing the factor of labor intensity for SOUT of workplaces, to determine the criteria for its negative action when used for the examination of the connection between the disease of the organ of hearing and the profession. In the «List of occupational diseases» in clause 2.4.2. indicated diseases associated with exposure to infrasound (IZ), among the manifestations of which, called sensorineural hearing loss bilateral. However, IZ, as well as low-frequency noise (LFN), were not previously considered as significant adverse factors in relation to the hearing organ in mass clinical trials, therefore, there are no expert criteria for the relationship between hearing loss and their impact, which could be applied in practice, which requires accumulation of evidence base for the subsequent substantiation of an independent nosological form of a disease of the organ of hearing, associated with mechanoacoustic exposure.

Sign in / Sign up

Export Citation Format

Share Document