Martin Mkandawire - Academia.edu (original) (raw)

Papers by Martin Mkandawire

Current opinion in food science, Feb 1, 2018

Journal of Chemical Physics, Feb 28, 2014

Social Science Research Network, 2022

Frontiers in Artificial Intelligence

During Basic screening, it is challenging, if not impossible to detect breast cancer especially i... more During Basic screening, it is challenging, if not impossible to detect breast cancer especially in the earliest stage of tumor development. However, measuring the electrical impedance of biological tissue can detect abnormalities even before being palpable. Thus, we used impedance characteristics data of various breast tissue to develop a breast cancer screening tool guided and augmented by a deep learning (DL). A DL algorithm was trained to ideally classify six classes of breast cancer based on electrical impedance characteristics data of the breast tissue. The tool correctly predicted breast cancer in data of patients whose breast tissue impedance was reported to have been measured when other methods detected no anomaly in the tissue. Furthermore, a DL-based approach using Long Short-Term Memory (LSTM) effectively classified breast tissue with an accuracy of 96.67%. Thus, the DL algorithm and method we developed accurately augmented breast tissue classification using electrical im...

Materials Advances

A growing quest for supercapacitors capable of quickly transferring energy has led to investigati... more A growing quest for supercapacitors capable of quickly transferring energy has led to investigations focusing on developing electrode materials that incorporate noble metals due to their superior electrical conductivity.

Application of Nanotechnology in Mining Processes, 2022

Due to increase in urbanization and industrialization, both water consumption and wastewater gene... more Due to increase in urbanization and industrialization, both water consumption and wastewater generation are high. It is a great challenge to treat and provide safe water to the society. The conventional treatment methods are energy and cost intensive. These limitations can be subsided by the application of nanotechnology that shows better efficiency in terms of treatment of wastewater. The use of nanoparticles increases the adsorption of dye and removal efficiency due to their smaller size and increased Surface to Volume (S/V) ratio. In this paper, magnetite nanoparticles were synthesized using Reverse Co-Precipitation method and their textile dye removal efficiency using adsorption was studied in treatment of blue dye water. The synthesized magnetite nanoparticles were qualitatively and quantitively characterized by Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), UV-Vis Spectroscopy and Cyclic Voltammetry (CV). The observed conti...

Journal of Applied Electrochemistry, 2021

Silicon nanowires combine a high electrical conductivity with low thermal conductivity due to the... more Silicon nanowires combine a high electrical conductivity with low thermal conductivity due to the small cross section offering a good template for sensing. Silicon p-type (100) substrate was used in this work to present a comparative study from a morphological point of view as well as for the electrical properties of silicon nanowires (SiNWs) etched by Ag-assisted chemical method in one-step and two-step process. The comparison between both techniques for SiNWs samples’ elaborated with Metal-Assisted Chemical Technique (MACE) was investigated by Scanning Electron Microscopy images that clearly show the presence of nanowires and the existence of porous silicon structure especially by Transmission Electron Microscopy technique. Several particles on the SiNWs surface such as oxygen and hydrogen elements were identified by Fourier-Transformed Infrared Spectroscopy measurements. The results indicate that the MACE’s steps influence the nucleation and motility of Ag particles, which leads to a different length and density structure within the nanowires. These parameters influence the electrochemical properties of the surface that was studied using electrochemical measurements. Impedance analysis revealed that the charge transfer resistance decreases with the length of the SiNWs dissimilar to the capacitance based on the cyclic voltammetry analysis. In this paper, we studied the electrochemical parameters which indicate that two-step MACE procedure presents a resistance nearly the half of the value of SiNWs produced using one-step MACE technique; as for the capacitance, it increases by 28.5%. We can notice that SiNWs produced using two-step MACE show better results for biosensing application. For that reason, we decide to functionalize the two-step MACE SiNWs to prove the ease of the surface modification. Deposition of nickel nanoparticles was analysed manifesting a good amelioration of the resistance with a factor of 2.5.

Water Science and Technology, 2021

The existing knowledge on the reactivity of green iron particles on textile dye and wastewater de... more The existing knowledge on the reactivity of green iron particles on textile dye and wastewater decolorization is very limited. In this study, the potential of green iron particles synthesized using grape leaves extract on reactive dye (reactive red 195, reactive yellow 145, reactive blue 4 and reactive black 5) decolorization were investigated. 95–98% of decolorization was achieved for all reactive dyes at 1.4–2.0 g/L of green iron. Maximum decolorization was attained at lower dye concentration and showed very little impact on decolorization when pH was increased from 3 to 11. The pseudo-first-order fit confirms the reaction between iron particles and dye molecules with rate constant 0.317–0.422 and it is followed by adsorption, data fit with pseudo-second-order model. Hence, not only adsorption but also the reduction process is involved in the reactive dye decolorization. Benzene, phenyl sodium, 2-chloro-1,3,5-triazine, naphthalene, sodium benzene sulfonate, benzene 1,2 di amine, a...

Nano and Bio‐Based Technologies for Wastewater Treatment, 2019

Journal of Contaminant Hydrology, 2018

Current Opinion in Food Science, 2018

International Journal of Phytoremediation, 2004

The potential of Lemna gibba L. to clean uranium and arsenic contamination from mine surface wate... more The potential of Lemna gibba L. to clean uranium and arsenic contamination from mine surface waters was investigated in wetlands of two former uranium mines in eastern Germany and in laboratory hydroponic culture. Water and plants were sampled and L gibba growth and yield were monitored in tailing ponds from the field study sites. Contaminant accumulation, growth and yield experiments were conducted in the laboratory using synthetic tailing water. Mean background concentrations of the surface waters were 186.0+/-81.2 microg l(-1) uranium and 47.0+/-21.3 microg l(-1) arsenic in Site one and 293.7+/-121.3 microg l(-1) uranium and 41.37+/-24.7 microg l(-1) arsenic in Site two. The initial concentration of both uranium and arsenic in the culture solutions was 100 microg l(-1). The plant samples were either not leached, leached with deionized H2O or ethylenediaminetetracetic (EDTA). The results revealed high bioaccumulation coefficients for both uranium and arsenic. Uranium and arsenic content of L gibba dry biomass of the field samples were as follows: nonleached samples > deionized H2O leached (insignificant ANOVA p = 0.05) > EDTA leached. The difference in both arsenic and uranium enrichment were significantly high between the nonleached and the other two lead samples tested at ANOVA p > 0.001. Estimated mean L gibba density in surface water was 85,344.8+/-1843.4 fronds m(-2) (approximately 1319.7 g m(-2)). The maximum specific growth rate was 0.47+/-0.2 d(-1), which exceeded reported specific growth rates for L gibba in the literature. Average yield was estimated at 20.2+/-6.7 g m(-2) d(-1), giving approximately 73.6+/-21.4 t ha(-1) y(-1) as the annual yield. The highest accumulations observed were 896.9+/-203.8 mg kg(-1) uranium and 1021.7+/-250.8 mg kg(-1) arsenic dry biomass for a 21-d test period in the laboratory steady-state experiments. The potential extractions from surface waters with L gibba L. were estimated to be 662.7 kg uranium ha(-1) yr(-1) and 751.9 kg arsenic ha(-1) yr(-1) under the above conditions.

Photochemical & Photobiological Sciences, 2016

Comparison of kinetics of photoexcitation migration from PC620 to APC Core in extracted and intac... more Comparison of kinetics of photoexcitation migration from PC620 to APC Core in extracted and intact pentacyclic phycobilisomes ofT. vulcanus. The extracted PBS does not have linker protein, while intact has them and they facilitate the migration.

Uranium, Mining and Hydrogeology, 2008

Prerequisites for energetically independent - sustainable- passive water treatment systems are ne... more Prerequisites for energetically independent - sustainable- passive water treatment systems are net primary production and a relatively slow to intermediate and turbulence, homogenous, and continuous through flow. Nutrients can be recycled and -if necessary- subsequently artificially applied. However, the situation is different when only the limited sorption capacity of litter, formerly bio-processed or fossil organic carbon (e.g. peat) is used.

Photochemical & Photobiological Sciences, 2015

To improve the energy conversion efficiency of solar organic cells, the clue may lie in the devel... more To improve the energy conversion efficiency of solar organic cells, the clue may lie in the development of devices inspired by an efficient light harvesting mechanism of some aquatic photosynthetic microorganisms that are adapted to low light intensity.

Applied Ecology and Environmental Research, 2005

Science of The Total Environment, 2011

Science of The Total Environment, 2005

Accumulation of arsenic in Lemna gibba L. was investigated in tailing waters of abandoned uranium... more Accumulation of arsenic in Lemna gibba L. was investigated in tailing waters of abandoned uranium mine sites, following the hypothesis that arsenic poses contamination risks in post uranium mining in Saxony, Germany. Consequently, macrophytes growing in mine tailing waters accumulate high amounts of arsenic, which might be advantageous for biomonitoring arsenic transfer to higher trophic levels, and for phytoremediation. Water and L. gibba sample collected from pond on tailing dumps of abandoned mine sites at Lengenfeld and Neuensalz-Mechelgrun were analysed for arsenic. Laboratory cultures in nutrient solutions modified with six arsenic and three PO(4)(3-) concentrations were conducted to gain insight into the arsenic-L. gibba interaction. Arsenic accumulation coefficients in L. gibba were 10 times as much as the background concentrations in both tailing waters and nutrient solutions. Arsenic accumulations in L. gibba increased with arsenic concentration in the milieu but they decreased with phosphorus concentration. Significant reductions in arsenic accumulation in L. gibba were observed with the addition of PO(4)(3-) at all six arsenic test concentrations in laboratory experiments. Plant samples from laboratory trials had on average twofold higher bioaccumulation coefficients than tailing water at similar arsenic concentrations. This would be attributed to strong interaction among chemical components, and competition among ions in natural aquatic environment. The results of the study indicate that L. gibba can be a preliminary bioindicator for arsenic transfer from substrate to plants and might be used to monitor the transfer of arsenic from lower to higher trophic levels in the abandoned mine sites. There is also the potential of using L. gibba L. for arsenic phytoremediation of mine tailing waters because of its high accumulation capacity as demonstrated in this study. Transfer of arsenic contamination transported by accumulations in L. gibba carried with flowing waters, remobilisation through decay, possible methylisation and volatilisation by L. gibba need to be considered.