Mosotho George

National University of Lesotho | NUL · Department of Chemistry and Chemical Technology

Fouling remains a major challenge in membrane-based water treatment technologies. As a result, contemporary research is geared towards membrane surface modification techniques to reduce fouling. Mitigation strategies involving incorporation of nanoparticles (NPs) into polymeric membranes has gained a remarkable interest. However, NPs leach is emine...

Project-based learning has received a lot of attention in academia across all education levels as one of the pedagogical approaches with the potential to promote scientific literacy and the development of work-related knowledge, skills, and competencies. Through mixed methods, this descriptive study assessed chemistry students' perceptions about a...

The unique nature of online teaching and learning has its own affordances and challenges. The purpose of this study was to assess science pre-service teachers’ perceptions about efficiency of online teaching and learning in science after experiencing it first-hand during the hard lockdowns due to Covid-19 pandemic. Mixed methods approach, with clos...

Unlabelled: Microplastic distribution and pollution as emerging contaminants have become a leading environmental issue globally, owing to their ecological and health implications on biota and humans. Although several bibliometric studies have been reported on microplastics, they are mostly restricted to selected environmental media. As a result, t...

Traditional teaching strategies dominate science classrooms in Lesotho, resulting in poor academic performance at each level. Information and Communication Technology tools such as simulations offer potential benefits for improving science teaching. The purpose of this quasi-experimental study was to evaluate the effect of simulations on learners'...

Essential oils are vital constituents of oil-bearing plants. However, their screening still demands harvesting of the plant for laboratory analysis. We report herein a simple, rapid and robust headspace bubble-in-drop microextraction screening technique (BID-SPME) requiring only small amounts of plant material. The optimised method uses 0.5 g of th...

Polycyclic aromatic hydrocarbons (PAHs) are a large group of diverse hazardous organic compounds that are relatively stable and widely distributed throughout the world’s ecosystems due to various anthropogenic activities. They are generally less soluble in water and have a low vapour pressure, but dissolve easily in adipose tissues; and they bioac...

http://deepblue.lib.umich.edu/bitstream/2027.42/173237/1/10052_2021_Article_9929.pdf

Geometry is among the cornerstones of mathematics because of its applicability in real life and its connection to other areas of mathematics. The reported study explored how the volume of 3D geometric shapes was taught in one high school in Lesotho. One male teacher and an intact class of sixty high school students were the participants of the stud...

Water, though vital for life, is also the route for transmission of water-borne diseases. Bottled water is consumed worldwide for its accessibility and the public perception of purity. However, this perception is usually not based on experimental results to confirm or invalidate it, especially where the sample commodity is not adequately tested for...

Agitation-assisted dispersive liquid-liquid extraction without a dispersing solvent is lately receiving considerable attention owing to the low to no solvent loss relative to its predecessor, which suffers severe extracting solvent loss. Herein, we report the application of a simple agitation-assisted dispersive liquid-liquid microextraction method...

Lesotho, one of the smallest countries in the world with an area of about 38,600 km², and wholly landlocked in South Africa, is characterized as one of the least developed countries with about 57% and 29% of households still classed as poor and ultra-poor, respectively, in 2009. Like many economies at its level, it is plagued with underdeveloped in...

A modification of a dispersive liquid-liquid microextraction (DLLME) procedure through the introduction a less dense binary-solvent mixture that floats on the surface of the aqueous solution for the extraction of polycyclic aromatic hydrocarbons from river water samples is presented in this study. The extracts were analyzed by gas chromatography co...

As a pre-concentration technique, bubble-in-drop, single-drop microextraction has received considerably less attention than its counterparts despite its efficiency, simplicity, eco-friendliness and affordability. Herein, we present the development of this method using a non-chlorinated solvent – dodecane and its application in the extraction and pr...

This study, based on the theory of Technological Pedagogical Content Knowledge investigated the effectiveness of introducing open source YouTube videos in the teaching and learning of the Chemistry topic ‘Group Properties’ at a high school in Lesotho. A quasi-experimental design was used for two conveniently selected Form D classes; one class used...

Chloroform seed extract from Schinus molle was analyzed for its phytochemical compositions by GC-MS. A total of 38 compounds were identified. S. molle has therapeutic applications in traditional medicine. Essential oils obtained from various parts of this plant are reported to have promising biological and pharmacological activity.

This paper reports the use of unfunctionalized and phenylalanine functionalized clays as an alternative cost effective, environmental friendly and efficient sorbent for the removal of Mn and Fe from polluted drinking water sources in Lesotho. The Mn and Fe metals were adsorbed on two different clays (clay A—a black clay and clay B—a yellow clay) co...

Landfill leachate contains a myriad of hazardous chemicals; as such, they should always be planned and constructed following approved guidelines. A sample of soil collected from the old quarry designated as the official solid waste disposal site in Maseru, the capital city of Lesotho, was exposed to two extraction techniques, namely Soxhlet and ref...

Volatile organic compounds (VOCs) derived from plants have been used in the fragrance industry since time immemorial. Herein we report on the rapid screening of VOCs from seeds of ripe Aframomum danielli (family, Zingiberaceae) using a polydimethylsiloxane fibre headspace solid phase microextraction coupled to a gas chromatography mass spectrometry...

Heavy metals are mostly occurring naturally in the environment and their concentrations may be altered by anthropogenic activities such as wastes disposal. The study investigated and determined the presence of heavy metals in Ts’osane solid-waste dumping site in Maseru. Soil samples were randomly collected from the dumping site and screened qualita...

During the shutdown of the CERN Large Hadron Collider in 2013-2014, an additional pixel layer was installed between the existing Pixel detector of the ATLAS experiment and a new, smaller radius beam pipe. The motivation for this new pixel layer, the Insertable B-Layer (IBL), was to maintain or improve the robustness and performance of the ATLAS tra...

As attention is drawn towards the monitoring of the so-called emerging pollutants, some common household chemicals are not well researched. Household antimicrobials can also present wastewater treatment challenges if not taken cognisance of. Herein we report the application of a recently reported coupled dispersive liquid-liquid micro-extraction (D...

As a search for affordable and efficient adsorbents for purification of textile wastewater continues, different natural materials are being investigated. Herein we report the investigation of clay obtained from Lesotho as a low cost and ecofriendly adsorbent for removal of blue textile dye from the stream running through the textile industry popula...

Background Plants contain a myriad of metabolites which exhibit diverse biological activities. However, in-depth analyses of these natural products with current analytical platforms remains an undisputed challenge due to the multidimensional chemo-diversity of these molecules, amplified by both isomerization and conjugation. In this study, we looke...

We report the application of the dispersive liquid-liquid microextraction coupled to hollow-fibre membrane-assisted liquid-phase microextraction and its application for extraction of atrazine and triclosan. Under optimum conditions, namely, 25 μ L of a 1 : 4 chlorobenzene : ethyl acetate mixture dispersed in 1 mL of aqueous sample, 10% (m/v) NaCl,...

As the search for efficient, affordable and environmentally friendly extraction methods continues, miniaturized solvent techniques are receiving considerable attention due to their simplicity, efficiency and fast extraction rates. Herein we report application of a modified dispersive liquid–liquid microextraction through the introduction of a secon...

Liquid-based miniaturized techniques have received a lot of attention recently resulting in the development of the liquid phase microextraction (LPME) and dispersive liquid-liquid microextraction (DLLME) techniques each offering unique benefits over the other technique. Herein we report a combination of the two techniques for the extraction of hexe...

The interest in small-scale manufacturing of simple products seems to be growing in Lesotho. However, this could have undesirable effects without insights into the chemical processes involved in such presumed simple processes. This manuscript reports the partnership between the National University of Lesotho and a small-scale manufacturer in the pr...

This article reports the application of a mixed-solvent ‘bubble-in-drop single drop micro-extraction’ method for pre-concentration of stilbene hormones – hexestrol and diethylstilbestrol from the water sample collected downstream of the cattle slaughterhouse. The optimised conditions for extraction included 75% chloroform–toluene mixture, 2:1 drop–...

Education is central to the development of human capacity of any country through shaping the citizenry for meaningful participation in the economy especially the knowledge-based economy. Funding of education, especially higher education, has been a subject of debates globally for quite a whilst especially since the adoption of basic education polic...

Headspace analysis is used widely and relies on volatilization of analytes into the headspace above the matrix. We detail the dramatic influence that added solvent can have on headspace analysis of phenols, without the requirement for specialized headspace vials. The use of water-immiscible solvents is key and leads to a 1-3 orders of magnitude enh...

Abstract Growth hormones are important biologically active compounds. However, they can cause deleterious effects if not used with care and their use in farmed animals is banned in the European Union. This study presents the development and application of a mixed-solvent "bubble-in-drop single drop micro-extraction" (BID-SDME) method for enrichment...

This article reports on a search for dark matter pair production in association with bottom or top quarks in 20.3 fb−1 of pp collisions collected at s√=8 TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets co...

The study was carried out to investigate the comparative nutritional value and physicochemical properties of home - made apple juice and mixed fruit juice (apple, banana and pear) with commercial 100% apple juice. The principal component analysis model revealed the complete difference between these juices with major source of difference being moist...

Detergents are very important substances in everyday life as they are used in laundry services. This manuscript reports the study of the commercial and laboratory prepared pine oil-based detergents employing the critical micelle concentration (CMC) phenomenon using conductivity measurements. The two samples showed the CMC values of 0.0725 g/cm 3 an...

This paper describes the trigger and offline reconstruction, identification and energy calibration algorithms for hadronic decays of tau leptons employed for the data collected from pp collisions in 2012 with the ATLAS detector at the LHC center-of-mass energy s√=8 TeV. The performance of these algorithms is measured in most cases with Z decays to...

A summary of the constraints from the ATLAS experiment on R-parity-conserving supersymmetry is presented. Results from 22 separate ATLAS searches are considered, each based on analysis of up to 20.3 fb−1 of proton-proton collision data at centre-of-mass energies of s√=7 and 8 TeV at the Large Hadron Collider. The results are interpreted in the cont...

The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb−1 of pp collision data at s√=7 TeV and 20.3 fb−1 at s√=8 TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the...

This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton–proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 fb−1 of collisions at a centre-of-mass energy of s√=8 TeV, although in some case an additional 4....

A search for Higgs boson decays to invisible particles is performed using 20.3 fb−1 of pp collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the Large Hadron Collider. The process considered is Higgs boson production in association with a vector boson (V=W or Z) that decays hadronically, resulting in events with tw...

The production of a W boson decaying to eν or μν in association with a W or Z boson decaying to two jets is studied using 4.6 fb−1 of proton-proton collision data at s√=7 TeV recorded with the ATLAS detector at the LHC. The combined WW + WZ cross section is measured with a significance of 3.4σ and is found to be 68±7 (stat.)±19 (syst.) pb, in agree...

This paper presents a measurement of the cross-section for high transverse momentum $W$ and $Z$ bosons produced in $pp$ collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=7~\rm TeV$ and correspond to an inte...

Tracking of metolachlor and atrazine herbicides in agricultural soils, from spraying through to harvest, was conducted using our recently reported "bubble-in-drop single-drop microextraction" method. The method showed good linearity (R(2) = 0.999 and 0.999) in the concentration range of 0.01-1.0 ng/mL with LOD values of 0.01 and 0.02 ng/mL for atra...

More than 85% of the energy source in the world is derived from burning of fossil fuels. In Lesotho, the residential energy demand coverage reaches 88% to urban and 95% in rural areas from forest vegetation. Such practices of utilizing biomass by cutting shrubs and woods for fuel consumption besides increasing the impact of greenhouse gas effect an...

Environmental monitoring can be a costly exercise for the legislative bodies to enforce regulatory mechanisms since most herbicides are hazardous in the environment. This study reports on the potential application of a cheaper sample preparation method termed 'bubble-in-drop' single drop micro-extraction (BID-SDME) method for monitoring metolachlor...

Sewage water microalgae are potential sources of feed stock for the production of biofuel. In this study, six treatment combinations of microbial strains (C, N1 and N2) in single and combined treatments were used in a 5L plastic container as anaerobic digester. The use of sewage water microalgae alone was used as a negative control; and a separate...

With the ever-increasing economic challenges facing education in Lesotho and indeed the world at large, there is a need for innovative solutions to support academic programmes without compromising quality. The use of computer simulations and video demonstrations is increasingly finding use globally in order to respond to economic challenges and pur...

Climate change has been a central concern in academic communities over the past few decades. Although many communities still do not necessarily understand its principles and implications, many of its effects are generally understood because they are experienced by everyone even at grassroots level. This case study demonstrates the experience and ap...

The process pp → W ± J/ψ provides a powerful probe of the production mechanism of charmonium in hadronic collisions, and is also sensitive to multiple parton interactions in the colliding protons. Using the 2011 ATLAS dataset of 4.5 fb−1 of s√ = 7 TeV pp collisions at the LHC, the first observation is made of the production of W ± + prompt J/ψ even...

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1 fb−1 of proton-proton collision data at s√ = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t¯ →tχ¯¯¯01 or t¯ →bχ¯¯¯±1 →bW(∗)χ¯¯¯01, where χ¯¯¯01 (χ¯¯¯±1) denotes th...

The differential cross section for the process Z/γ ∗ → ℓℓ (ℓ = e, μ) as a function of dilepton invariant mass is measured in pp collisions at s√ = 7 TeV at the LHC using the ATLAS detector. The measurement is performed in the e and μ channels for invariant masses between 26 GeV and 66 GeV using an integrated luminosity of 1.6 fb−1 collected in 2011...

This paper presents the performance of the ATLAS muon reconstruction during the LHC run with pp collisions at s√=7–8 TeV in 2011–2012, focusing mainly on data collected in 2012. Measurements of the reconstruction efficiency and of the momentum scale and resolution, based on large reference samples of J/ψ→μμ, Z→μμ and Υ→μμ decays, are presented and...

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a cha...

A search is presented for direct top squark pair production using events with at least two leptons including a same-flavour opposite-sign pair with invariant mass consistent with the Z boson mass, jets tagged as originating from b-quarks and missing transverse momentum. The analysis is performed with proton–proton collision data at s√=8\ TeV collec...

A measurement is presented of the ϕ×BR(ϕ→K+K−) production cross section at s√ = 7 TeV using pp collision data corresponding to an integrated luminosity of 383 μb−1, collected with the ATLAS experiment at the LHC. Selection of ϕ(1020) mesons is based on the identification of charged kaons by their energy loss in the pixel detector. The differential...

This paper presents a study of the performance of the muon reconstruction in the analysis of proton–proton collisions at s√=7 TeV at the LHC, recorded by the ATLAS detector in 2010. This performance is described in terms of reconstruction and isolation efficiencies and momentum resolutions for different classes of reconstructed muons. The results a...

Many of the interesting physics processes to be measured at the LHC have a signature involving one or more isolated electrons. The electron reconstruction and identification efficiencies of the ATLAS detector at the LHC have been evaluated using proton–proton collision data collected in 2011 at s√=7 TeV and corresponding to an integrated luminosity...

The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp?????*??????, assuming that excited leptons are produced via contact interactions. The analysis is based on 13?fb?1?of pp collisions at a centre-of-mass energy of 8?TeV. No evidence for excited leptons is found, and a limit is...