Search

In this study, the production of an eco-friendly curcumin based nanocomposite fingerprint labeling powder is reported for the first time. This powder was prepared from thermal power plant waste known as coal fly ash. 3-aminopropyltrimethoxysilane (APTMS) was covalently interacted with coal fly ash (CFA/APTMS) and curcumin (CUR) was encapsulated onto CFA/APTMS to give a novel and eco-friendly CFA/APTMS/CUR nanocomposite for LFPs detection with the powder dusting method. Several instrumental techniques including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV–visible spectroscopy, fluorescence spectroscopy (FL), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), and transmission electron microscopy (TEM) were used to characterize this nanocomposite. The CFA/APTMS/CUR nanocomposite was applied as a forensic powder for the development of latent fingerprint (LFPs) images on various porous and non-porous substrates. Level 2 (island, origination, bifurcation, termination, fork, dot, and bridge) and Level 3 (sweat pores and shape of triangles, round, and irregular) were the features of the LFP images. Under visible light conditions, the aging LFPs images were clearly detected on an aluminum foil surface using the nanocomposite powder, which had good sensitivity and minimal background interference. Additionally, LFPs images were developed using CFA/APTMS/CUR nanocomposite on leather substrates for belts and shoes in order to confirm the benefits of the nanocomposite's high sensitivity. This nanocomposite improved LFPs images with unique patterns and showed excellent performance on a variety of surfaces for the development of LFPs. These findings therefore proved that the powdered CFA/APTMS/CUR nanocomposite can be effectively utilized for the development of LFPs images at important crime scenes and for the biometric identification of criminal suspects through fingerprint comparison.

Heavy metals are posing problems in the environment and one of them is lead. The disposal of lead in our water systems comes from industries such as the paint, mining, and electroplating industries. In this study, Carbon nanoparticles (CNPs) were synthesized from carbon soot by using a refluxed method. The CNPs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction pattern (XRD) Brunauer–Emmett–Teller (BET), Thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Transmission Electron Microscope (TEM). Batch adsorption studies were carried out for lead adsorption. Pb2+ uptake fitted well with the pseudo-second-order kinetics model, while the adsorption isotherm fitted best to the Langmuir model, with a maximum adsorption capacity of 67.98 mg/g at 25 °C. The obtained thermodynamic parameters demonstrated that the adsorption of Pb2+ ions by carbon nanoparticles was exothermic and spontaneous. The spent adsorbent was then used in cement production, demonstrating that Pb2+-CNPs can be a promising material for cement production when its quantity exceeds 1.2 %.

Carbon-based material powders have been applied in fingerprints development. However, sustaining fluorescence in solid substances remains difficult due to the severe emission suppression of carbon-based compounds in solid-state materials. This study is the first to report on the use of activated wool char coated on manganese-doped iron oxide nanoparticle (WLC-H3PO4–MnFe2O3) as a novel nanocomposite (nCOM) for latent fingerprint (LAFPs) detection via the powder dusting approach. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Spectrometry (EDS), and Transmission Electron Microscopy (TEM), XPS (X-ray photoelectron spectroscopy) were used to analyze this nanocomposite. The nanocomposite produced good LAFP pictures on non-porous substrates such as aluminium foil and aluminium sheets. Moreover, this nanocomposite could be utilized as a labeling agent and could aid in the detection of LFP under visible light by providing distinct readability ridges and high-contrast fingerprint pictures.

Due to their propensity to bioaccumulate, lead and cadmium, two hazardous heavy metals, can seriously disrupt the ecosystem. These metals have the potential to cause major environmental and human health problems. Herein, carbon quantum dots were used to coat silica nanoparticles to create a brand-new nanocomposite called CQTDs/SiO2NPs. Cd2+ and Pb2+ ions were effectively removed from water and preconcentrated using the produced nanocomposite. The novel nanocomposite was characterized using SEM, TEM, FT-IR, XRD, and XRF. The bending vibration of Si–O–Si/Si–O–C and Si–OH are responsible for the FT-IR bands that were detected in the nanocomposite at 1041 and 954 cm−1, respectively. XRD demonstrated that the silica nanoparticles were amorphous. Additionally, SEM and TEM analysis revealed the nanocomposite's shape, which was determined to be spherical with minimal agglomeration.While XPS demonstrated the binding energy of the functional group present in the composite and further confirmed the metal loaded onto the adsorbent. On CQTDs/SiO2NPs nanocomposite, the optimum pH and dosage were 8 and 0.2 g respectively. The highest Cd2+ and Pb2+ ion adsorption capabilities are 14.87 and 38.49 mg g −1, respectively. The use of the nanocomposite resulted in an exothermic, physical and non-spontaneous adsorption that closely resembled the Langmuir equilibrium isotherm and the second-order kinetics. The metal loaded adsorbent used as a fingerprint labelling agent displayed clear fingerprint ridges and degraded the sulfamethoxazole (SMX) for up to 90 %. The prepared composite has proven to be coherent in heavy metal removal and can thus be reused in Latent fingerprint and photocatalysis applications. The reuse of the nanocomposite in the above-mentioned applications is an alternative solution to avoid secondary pollution.

Manganese is one of the heavy metals that is a major environmental concern when present in large amount. Manganese is discarded into water systems by numerous industries, including mining, batteries and electroplating etc. Pineapple leaves were applied as a biomass source to produce a magnetic hydrothermal treated hydochar nanocomposite; Fe3O4-HC. The BET surface area of Fe2O3-HC nanocomposite was 21.27 m2/g. Batch adsorption experiments revealed that the uptake of Mn2+ fit well in the pseudo second kinetics model, while the adsorption isotherm best fit the Freundlich model, with a maximum adsorption capacity of 2.99 mg/g at 25 °C and a pH of 5. The obtained thermodynamic parameters demonstrated that Mn2+ ion adsorption using the Fe2O3-HC nanocomposite was endothermic and nonspontaneous. Additionally, Fe2O3-HC nanocomposite demonstrated to be highly selective towards Mn2+ ions in the presence of other ions. The removal percentage of Mn2+ from a real water sample spiked with 50 mg/L Mn2+ was reported to be 53.2%. The spent adsorbent was then used to detect latent fingerprints, which revealed that Mn2+-Fe2O3-HC nanocomposite generated better and clear latent fingerprints than Fe2O3-HC nanocomposite.

In this study potassium salts such as KF, KCl and KBr were doped onto g-C3N4 to form KX-g-C3N4 (X = F, Cl and Br) via a thermal method. The KX-g-C3N4 was characterized by various instrumentation techniques such as UV–visible, FT-IR, XRD, Photoluminescence, TGA, BET, Raman, SEM, EDAX, HR-TEM, and Zeta potential. KX-g-C3N4 was explored for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. Among them, KF-g-C3N4 showed excellent photocatalytic degradation of methylene blue (MB) under visible light irradiation. The KF-g-C3N4 significantly reduced the electrons–holes recombination rate when compared to KCl-g-C3N4, KBr-g-C3N4 and g-C3N4. The photocatalytic degradation mechanism was also studied with KF-g-C3N4.

This work provides a novel approach to prepare nitrogen-doped carbon nanoparticles (CNPs) coated on a cerium oxide nanorods nanocomposite (N-CNPs/CeO2NRsnC) for the uptake of cadmium (Cd2+) ions and re-using the spent adsorbent, Cd2+-CNPs/CeO2NRsnC for latent fingerprint detection (LFP). N-CNPs were prepared by a thermal method with urea and cabbage powder as precursors. N-CNPs/CeO2NRsnC was developed with N-CNPs and CeO2NRs with a hydrothermal method and characterized by various instrument methods like UV-visible, FT-IR, XRD, BET, XPS, SEM, and TEM. The N-CNPs/CeO2NRsnC had a greater surface area (9.96 m2/g) than N-CNPs (0.64 m2/g). The synthesized N-CNPs/CeO2NRsnC proved to be a good sorbent material to remove Cd2+ from water at a maximum pH 8 and dosage 10 mg/L. The adsorption was spontaneous and endothermic at 25 ºC. In addition, Cd2+-N-CNPs/CeO2NRsnC has been shown to be sensitive and selective for LFP identification on several porous substrates. It is therefore a good labeling agent for latent fingerprint identification in forensic science.

This study reports a new approach of preparation of carbon dots coated on aluminum oxide nanofibers (CDs/Al2O3NFs) nanocomposite and reusing the spent adsorbent of lead (Pb2+) ions loaded adsorbent (Pb2+-CDs/Al2O3NFs) nanocomposite for latent fingerprint detection (LFP) after removing Pb2+ ions from aqueous solution. CDs/Al2O3NFs nanocomposite was prepared by using CDs and Al2O3NFs with adsorption processes. The prepared nanocomposite was then characterized by using UV–visible spectroscopy (UV–visible), Fourier transforms infrared spectroscopy (FTIR), Fluorescence, X-ray diffraction pattern (XRD), scanning electron microscope (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), Zeta potential, X-ray photoelectron spectroscopy (XPS). The average size of the CDs was 51.18 nm. The synthesized CDs/Al2O3NFs nanocomposite has proven to be a good adsorbent for Pb2+ ions removal from water with optimum pH 6, dosage 0. 2 g/L. The results were best described by the Freundlich Isotherm model. The adsorption capacity of CDs/Al2O3NFs nanocomposite showed the best removal of Pb2+ ions with qm = (177. 83 mg/g), when compared to the previous reports. This adsorption followed the pseudo-second order kinetic model. ΔG and ΔH values indicated spontaneity and the endothermic nature of the adsorption process. CDs/Al2O3NFs nanocomposite therefore showed potential as an effective adsorbent. The data were observed from adsorption–desorption after 6 cycles which showed good adsorption stability and re- usability of CDs/Al2O3NFs nanocomposite. Furthermore, the spent adsorbent of Pb2+-CDs/Al2O3NFs nanocomposite has proven to be sensitive and selective for LFP detection on various porous substrates. Hence Pb2+-CDs/Al2O3NFs nanocomposite can be reused as a good fingerprint labelling agent in LFP detection so as to avoid secondary environmental pollution by disposal of the spent adsorbent.

In this study a nanocomposite of graphitic carbon nitride-silver polyvinylpyrrolidone (gCN-AgPVP) was fabricated for the electrochemical detection of paracetamol (PAR). The nanocomposite of gCN-AgPVP showed superior electrocatalytic ability for PAR detection since it is selectively adsorbed by electrostatic interactions of the nanocomposite of gCN-AgPVP. This selective adsorption is also facilitated by charge assisted interactions between the PAR and gCN-AgPVP surfaces. The stability of the GCE/gCN-AgPVP was characterised using cyclic voltammetry (CV) at potentials ranging from −0.2 to +0.7 V and a scan rate of 50 mV/s. Square wave voltammetry (SQWV) was employed to characterise and detect PAR. The analysis was conducted on modified GCE/gCN-AgPVP in 0,1M phosphate buffer solution (PBS) and pH 6.1. GCE/gCN-AgPVP showed excellent performance in detecting PAR in the concentration range of 0.2–100 µM with a correlation coefficient of 0.9951 respectively. The calculated detection limit (LOD) was 0.079 µM.

In this study, an N-CNS/ZnO nanocomposite was used to adsorb the Cd2+ ion from an aqueous solution, and the spent Cd-loaded absorbent was reused in blood fingerprint detection. N-carbon nanosheets (N-CNS) were produced from potato peels and then coated with ZnO nanoparticles. XRD, TEM, SEM, and FTIR were used to examine the sample functionality and Surface morphology. The effect of pH, adsorbent dosage, temperature, and time was examined using ICP-OES. Removal efficiencies optimum conditions for the Cd2+ were pH 8 with 99.05 %, adsorbent dosage of 100 mg with 99,97 %, temperature (55) with 93,34 % and time (3 h) with 91,24 %. Additionally, the adsorption pseudo-second-order and Langmuir isotherm models were best fitted for Cd2+ ion removal. The maximum adsorption capacity of Cd2+ ions was 8.762 mg/g. Therefore, N-CNS/ZnO nanocomposite can remove Cd2+ ions in wastewater, and its potential for re-use in blood fingerprint detection helps eliminate secondary environmental pollution.

Living organisms are created by carbohydrate biopolymers such as chitosan, carboxymethyl cellulose, alginate and lignin. These carbohydrate biopolymers have been extensively used for environmental applications because they are bio-degradable, bio-compatible, non-toxic and inexpensive. Recently, carbohydrate biopolymers have been used to prepare different nanocomposite adsorbents for treatment of wastewater. These adsorbents explored the removal effectiveness of inorganic pollutants from aqueous solution. This review article discusses the synthesis and application of chitosan, carboxymethyl cellulose, alginate and lignin nanocomposites as adsorbents for heavy metals. Toxic metals can be efficiently absorbed by cross-linkers, distributed in aqueous solutions of divalent heavy metal ions to examine their polymer absorption capacity. These nanocomposites were used for the adsorption of highly toxic metals such as Cd2+, Pb2+ and Zn2+ in water. To make heavy metal ion uptake more effective, more functionalization has been implemented such as blending, grafting, or mixing with different nanomaterials with an extra functional group. The integration of the second part into the main polymer chain not only adds functionality but also increases mechanical efficiency, one of the core criteria for adsorbent recyclability. The remediation method of metal ions from wastewater is cheaper as long as the adsorbent is reused. Furthermore, they exhibited good performance for the reuse of spent adsorbents after adsorption-desorption processes including latent fingerprint detection with nanomaterials by using the powder dusting method. Chitosan, carboxymethyl cellulose, alginate and lignin based nanocomposites have demonstrated better adsorption activities due to great physical and chemical properties for the chelation of heavy metals such as Cd2+, Pb2+ and Zn2+ from water and also higher regeneration with various eluents after several desorption-adsorption cycles. In addition, reuse of the spent adsorbents in latent fingerprint detection with different nanomaterials is discussed. Finally, this review article makes recommendations for future studies in light of environmentally favourable and economical applications.

Background. With the recent increase in antibiotic resistance to conventional antibiotics, gold nanoparticles, and medicinal plants, extracts present an interesting alternative. Objectives. This study aimed to synthesize, characterize, and evaluate Pyrenacantha grandiflora Baill extracts and gold nanoparticle conjugates against pathogenic bacteria. Methods. We synthesized gold nanoparticles by chemical and biological methods. The nanoparticles were characterized by the use of UV-visible spectrophotometry, followed by transmission electron microscopy (TEM) and energy-dispersive X-ray analysis (EDX). Gold nanoparticles were conjugated to plant extracts and analyzed with a Fourier-transform infrared spectroscope (FTIR). We determined the antimicrobial activity of the conjugates using well diffusion and the microdilution assays. Results. The UV–visible spectra of gold nanoparticles showed a synthesis peak at 530 nm. FTIR analysis indicated functional biomolecules that were associated with plant extract conjugated gold nanoparticles; the formation of C–H group and carbonyl (C=O) groups, –OH carbonyl, and C≡C groups were also observed. Biologically synthesized nanoparticles were star-shaped when observed by TEM with an average size of 11 nm. Gold nanoparticles synthesized with P. grandiflora water extracts showed the largest zone of inhibition (22 mm). When the gold nanoparticles synthesized by the biological method were conjugated with acetone extracts of P. grandiflora, MIC as low as 0.0063 mg/mL was observed against beta-lactamase producing K. pneumonia. The activity of acetone extracts was improved with chemically synthesized gold nanoparticles particularly when beta-lactamase producing E. coli and MRSA were used as test organisms. A synergistic effect was observed against all tested bacteria, except for MRSA when gold nanoparticles were conjugated with acetone extract. Conclusion. Overall, P. grandiflora tuber extracts conjugated with gold nanoparticles showed a very good antibacterial activity that improved both plant extract and gold nanoparticle’s individual activity.

The training and development of employees in the airline industry usually take place within a decentralized structure and may result in fragmented and costly initiatives. To improve the current practice a corporate university (CU) model to be implemented in the airline is proposed. For the purpose of the study qualitative interviews were held, human documents were studied and participant observation and the views of employees of the South African airline industry were sought regarding training in general and CUs in particular. The study revealed support for the CU concept because it would encourage continuous learning at all levels in the organisation and would place emphasis on both employee and organisational needs.

Monitoring of human rights in the health sector is of crucial importance to ensure the effective realisation of these rights, especially in the light of human rights i6uses in the history of our country. Monitoring means comprehensive efforts to collect appropriate data to determine whether performance of institutions or individuals conforms to accepted human rights standards. Monitoring can take place by means of a number of strategies and at different levels, considering certain'' preconditions for monitoring. This article outlines information on mechanisms for monitoring of human rights. Furthermore it seeks to raise relevant issues that warrant further consideration in order to inform an effective approach to the monitoring of human rights in the health sector.

In general, estuaries may be classified variously according to inlet dynamics, geomorphology or whether they are tide or river dominated or, on a combination of all three factors. In KwaZulu-Natal (KZN), South Africa, the four recognised estuary types are temporary opened-closed estuaries (TOCEs), permanently opened estuaries, estuarine lakes and river mouths. Since physico-chemical parameters are important in defining the estuarine environment, multiple Pearson correlations were performed between summer datasets of five of these parameters: temperature (°C), salinity (ppt), pH and turbidity (Nephelometric Turbidity Units (NTU)) according to clustered estuary types for all estuaries of KZN. It was found that very few significant relationships exist in all estuary types. These results are partly reflective of the sampling dataset. During summer, open mouth conditions commonly prevail for several estuaries following seasonal hinterland rainfall. Mixing of waters due to tidal influences and fluvial input from the upper catchment in KZN's shallow estuaries is known to inhibit stratification resulting in fewer pycnoclines and greater turbidity fluctuations. pH changes are closely linked to density changes (temperature and salinity) in water hence statistical relationships may not always be observable. It is clear that physico-chemical interactions are complex and long term sampling with seasonality and mouth State dynamics need to be taken into consideration. There is a need to develop a more holistic understanding of estuarine ecosystem functioning in this region. [ABSTRACT FROM AUTHOR]

Abstract The linear stability theory is used to investigate analytically the effects of gravity modulation on solutal convection in the mushy layer of solidifying binary alloys. The gravitational field consists of a constant part and a sinusoidally varying part, which is synonymous to a vertically oscillating mushy layer subjected to constant gravity. The linear stability results are presented for both the synchronous and subharmonic solutions. It is demonstrated that up to the transition point between the synchronous and subharmonic regions, increasing the frequency of vibration rapidly stabilizes the solutal convection. Beyond the transition point, further increases in the frequency tend to destabilize the solutal convection, but gradually. It is also demonstrated that the effect of increasing the ratio of the Stefan number and the solid composition (?0) is to destabilize the solutal convection. [ABSTRACT FROM AUTHOR]

Background: Although iron supplementation may prevent iron deficiency anaemia (IDA) during pregnancy, a nutrition education tool highlighting the importance of iron supplementation during pregnancy is also important. Objectives: The aim was to develop and test a nutrition education tool on iron supplementation for pregnant women. Design: A cross-sectional study was conducted. Setting: Mutare City Clinic, Manicaland province, Zimbabwe. Subjects: Sixty-seven pregnant women in their second or third trimesters of pregnancy and attending Mutare City Clinic for antenatal care (ANC) participated in the study. Outcome measures: The preferences of pregnant women regarding form, structure and content of the nutrition education tool were established using eight focus-group discussions (FGDs) in which 67 pregnant women participated. Three additional FGDs were conducted with another 28 pregnant women to assess the user-friendliness and acceptability of the developed tool. Results: A pamphlet was the most preferred tool, with English being the most preferred language, along with some Shona phrases. Women wanted information on IDA, dosage, duration and side-effects of iron supplementation and iron food sources to be included in the pamphlet. The participants identified clinics, pharmacies and churches as ideal sites for dissemination of the tool. Conclusions: A pamphlet on iron supplementation in simple English with some Shona phrases was the nutrition education tool most preferred by the pregnant women. Offering the pamphlet together with iron supplements to pregnant women could improve compliance with iron supplements. However, follow-up ANC consultations are important for effective implementation of all key messages in the pamphlet.

A primary endovascular approach is the mainstay of intervention for type C aortoiliac disease. When the femoral artery is unsuitable, upper extremity access can be critical in the setting of severe tortuosity or occlusive disease. The axillary artery represents alternative upper extremity access that may accommodate larger sheath sizes for therapeutic interventions. A 44-year-old gentleman with a history of right below-knee amputation was referred to the vascular unit with a left foot non-healing wound post wound debridement for diabetic foot ulcer. On examination, the left foot was non-salvageable with pitting oedema extended until knee level. Left lower limb pulses were non-palpable from femoral downwards. A biphasic signal was audible at the left femoral and monophasic at the popliteal. Photoplethysmography showed poor flow distally. Computed tomography angiogram revealed a 12 cm long segment total occlusion of the left external iliac artery just below the bifurcation of iliac vessel. On the right side, there was a long segment occlusion of the superficial femoral artery and calcified common femoral artery. The left axillary artery was used as an access and angioplasty was performed successfully. The advantages of upper extremity access in the axillary artery include the relatively large size and lower atherosclerotic burden. Larger profile stents for aortoiliac occlusion can easily be handled with a good strength through an axillary approach which is antegrade compared to a retrograde femoral approach. With the advancement of safety features of endovascular devices complications with an axillary approach have become less in the recent era.

This qualitative study focuses on primary schools' state of readiness for the introduction of early childhood education. Adopting a multiple case study design, the article explores, through semi-structured interviews and documentation, school heads, teachers-in-charge and classroom teachers' perceptions of their respective schools' state of readiness for the installation and implementation of early childhood education. The study established that, while classroom teachers were adequately qualified to implement early childhood education, teachers-in-charge were not. Secondly, school heads received limited induction for the introduction and implementation of early childhood education. Additionally, inadequate teaching-learning resources and lack of on-going teacher support contributed to schools' lack of readiness for the introduction of early childhood education. The study recommends interventions that curriculum planners and implementers can utilise in order to create conditions that enable primary schools to be ready for introducing and implementing early childhood education.

Background: The prevalence and incidence of diabetes in South Africa are high and are expected to increase. Mortality and morbidity may be related to hypoglycaemia, and there is limited information on hypoglycaemia from private practice sites. The aim of this study was to assess patients’ education about, knowledge of and response to hypoglycaemia. Methods: The study site was a general practice, and participants were all patients with diabetes who presented to the practice over a 1-month period. Data were collected using a closedended questionnaire and analysed descriptively. Findings: Most respondents were South Africans of Indian origin and were diagnosed with diabetes at a relatively young age. Despite attending a private practice, most had low incomes and low schooling levels. Just under half reported having experienced hypoglycaemia, and there was a strong association between hypoglycaemia and insulin use. Many reported never having received any education around hypoglycaemia. Discussion: The study highlights the need for early screening for diabetes in this vulnerable population. Hypoglycaemic education should consider low schooling levels even in a private general practice, and further study is required on the quality and frequency of education provided in general practice. Keywords: diabetes; hypoglycemia, KwaZulu-Natal; hypoglycemic education