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Determination of the levels of heavy metals in water, pastures and meat tissues of Pedi goats across two rivers in Limpopo Province, South AfricaManamela, Makwena Precious January 2021 (has links)
Thesis (M. Sc. Agriculture (Animal Production)) -- University of Limpopo, 2021 / The study was carried out to determine the concentration levels of mercury (Hg), lead
(Pb), cadmium (Cd), chromium (Cr), nickel (Ni) and zinc (Zn) in water, soil, witbuffels
grass and meat of goats reared along the river banks of Middle Olifants (Mogalatsana
village) and Mogalakwena (Papegaai village) rivers. The samples were collected from
the river water, soils along the river banks, grass grown along the river banks and male
Pedi goats reared in Mogalatsana and Papegaai villages. The samples were analysed
for the selected heavy metals with an inductively coupled plasma mass spectroscopy
(ICP-MS). Data was analysed as in a complete randomised design. The results of
selected heavy metals in water of both rivers ranged from 0.00 mg/litre of water (Ni
and Cr) to 0.04 mg/litre of water (Hg). The concentration levels of selected heavy
metals in water were similar (P>0.05) for Middle Olifants and Mogalakwena rivers. The
concentration levels of selected heavy metals in the soils along the banks of Middle
Olifants and Mogalakwena rivers ranged from 0.00 mg/kg DM soil (Hg and Cd) to
63.70 mg/kg DM soil (Cr). There were similar (P>0.05) concentration levels of
selected heavy metals in the soils along the banks of Middle Olifants and
Mogalakwena rivers. Heavy metal concentration levels in the witbuffels grass grown
along the banks of Middle Olifants and Mogalakwena rivers ranged from 0.00 mg/kg
DM of grass (Hg and Cd) to 5.05 mg/kg DM of grass (Zn). Similar (P>0.05)
concentrations of selected heavy metals were observed in witbuffels grass grown
along the banks of Middle Olifants and Mogalakwena rivers. However, the
concentration levels of Zn, Pb and Cd in water from both sites were above
internationally maximum permissible levels, indicating that the water from these rivers
was not safe for drinking by humans and animals. The concentration levels of Ni and
Pb in soils from both sites were above internationally recommended maximum
permissible limits. Similarly, chromium concentration levels in witbuffels grass from
both sites were above the recommended maximum permissible limits for livestock,
indicating that the grass was not safe for consumption by livestock. It is recommended
that further studies be conducted to ascertain these findings.
Blood, liver, kidney and meat samples of yearling male Pedi goats grazing along the
banks of Middle Olifants river (Mogalatsana village) had similar (P>0.05) Cr, Cd, Hg,
Ni and Pb concentration levels, respectively. However, goat liver samples had higher
(P<0.05) Zn concentrations than meat, kidney and blood samples. Samples of goat
v
meat contained higher (P<0.05) Zn concentrations than those of kidneys and blood.
Similarly, goat kidney samples contained more (P<0.05) Zn than blood samples.
Blood, liver, kidney and meat samples of Pedi goats grazing along the banks of
Mogalakwena river (Papegaai village) contained similar (P>0.05) concentration levels
of Cr, Cd, Hg, Ni and Pb, respectively. However, goat meat samples contained higher
(P<0.05) Zn concentrations than liver, kidney and blood samples. Samples of goat
liver contained higher (P<0.05) Zn concentration levels than kidney and blood
samples. Similarly, goat kidney samples contained more (P<0.05) Zn than blood
samples.
Meat, blood, liver and kidney samples of male Pedi goats raised in Mogalatsana and
Papegaai villages had similar (P>0.05) chromium, cadmium, mercury, nickel and lead
concentrations, respectively. However, liver and kidney samples of goats from
Mogalatsana village had higher (P<0.05) zinc levels than those from Papegaai village.
Blood and meat samples of goats from Papegaai village had higher (P<0.05) zinc
levels than those from Mogalatsana village. The concentration levels of Zn, Ni, Pb, Cr
and Cd in the blood, liver, kidney and meat samples of male Pedi goats reared along
the banks of Middle Olifants and Mogalakwena rivers were within the maximum
permissible levels for human consumption. Mercury concentration levels in liver,
kidney and meat samples of the goats were within the maximum permissible levels for
human consumption. However, mercury concentration levels in the blood of goats
grazing along the banks of Middle Olifants and Mogalakwena rivers were above the
maximum permissible limit of 0.2 mg/litre of blood. It was concluded that meat, livers
and kidneys of the goats were fit for human consumption. However, blood from these
goats was not fit for human consumption.
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Variants of Ferroelectric Hafnium Oxide based Nonvolatile MemoriesMikolajick, T., Mulaosmanovic, H., Hoffmann, M., Max, B., Mittmann, T., Schroeder, U., Slesazeck, S. 26 January 2022 (has links)
Ferroelectricity is very attractive for nonvolatile memories since it allows non-volatility paired with a field driven switching mechanism enabling a very low-power write operation. Non-volatile memories based on ferroelectric lead-zirconium-titanate (PZT) (see fig. la) are available on the market for more than a quarter of a century now [1]. Yet they are limited to niche applications due to the compatibility issues of the ferroelectric material with CMOS processes and the associated limited scalability [2]. The discovery of ferroelectricity in doped hafnium oxide has revived the activities towards a variety of scalable ferroelectric nonvolatile memory devices
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Thermodynamic database for Pb and its compounds - data selectionMoog, Helge 25 August 2022 (has links)
This report documents the selection of thermodynamic data for lead and lead compounds. Except for elemental lead, it is restricted to lead in the oxidation state +II (plumbous lead). Besides formation constants and, in part, enthalpies of formation and standard entropies, interaction coefficients for the correction of activity coefficients following the Pitzer formalism are provided. Aqueous complexes of lead with chloride, sulphate, and hydroxide are explicitly accounted for in the Pitzer model. Wherever possible, the validity of selected data is tested by recalculating experimental data. The presented data set is valid for 298.15K only.
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