Unveiling Semiconductor Nanostructured Based Holmium-Doped ZnO: Structural, Luminescent and Room Temperature Ferromagnetic Properties.

This research work describes the synthesis of ZnO nanostructures doped with Ho ions using a conventional sol-gel synthesis method. The nanostructured produced exhibited a wurtzite hexagonal structure in both ZnO and ZnO:Ho (0.25, 0.

Elucidating the Trajectory of the Charge Transfer Mechanism and Recombination Process of Hybrid Perovskite Solar Cells.

Perovskite-based solar cells (PSCs) have attracted attraction in the photovoltaic community since their inception in 2009. To optimize the performance of hybrid perovskite cells, a primary and crucial strategy is to unravel the dominant charge transport mechanisms and interfacial properties of the contact materials. This study focused on the charge transfer process and interfacial recombination within the n-i-p architecture of solar cell devices.

Underpinning the Interaction between NO and CuO Nanoplatelets at Room Temperature by Tailoring Synthesis Reaction Base and Time.

An approach to tailor the morphology and sensing characteristics of CuO nanoplatelets for selective detection of NO gas is of great significance and an important step toward achieving the challenge of improving air quality and in assuring the safety of mining operations. As a result, in this study, we report on the NO room temperature gas-sensing characteristics of CuO nanoplatelets and the underlying mechanism toward the gas-sensing performance by altering the synthesis reaction base and time. High sensitivity of ∼40 ppm to NO gas at room temperature has been realized for gas sensors fabricated from CuO nanoplatelets, using NaOH as base for reaction times of 45 and 60 min, respectively at 75 °C.

Facile control of room temperature nitrogen dioxide gas selectivity induced by copper oxide nanoplatelets.

Development of room-temperature operating gas sensors, utilizing p-type CuO nanoplatelets for air quality monitoring with excellent response, high sensitivity and good reliability, is highly desirable. Therefore, in this work, we investigated both the influence of synthesis reaction temperature and time on the sensitivity, selectivity, and response of CuO nanoplatelets prepared through the hydrothermal synthetic method, in the presence of NaOH as base, without the support of any surfactant. The gas sensing findings revealed that the CuO nanoplatelets NO sensitivity and selectivity can be controlled and tuned by adjusting the synthesis reaction temperature and time, while maintaining the morphology.

A highly responsive NH sensor based on Pd-loaded ZnO nanoparticles prepared via a chemical precipitation approach.

The gas-detecting ability of nanostructured ZnO has led to significant attention being paid to the development of a unique and effective approach to its synthesis. However, its poor sensitivity, cross-sensitivity to humidity, long response/recovery times and poor selectivity hinder its practical use in environmental and health monitoring. In this context, the addition of noble metals, as dopants or catalysts to modify the ZnO surface has been examined to enhance its sensing performance.

Effects of stearic acid and irradiation alone and in combination on properties of amylose-lipid nanomaterial from high amylose maize starch.

This study determines the effects of stearic acid and gamma irradiation, alone and in combination, on properties of amylose-lipid nanomaterials from pasted high amylose maize starch (HAMS) with and without alpha amylase hydrolysis. HAMS was incorporated with stearic acid (0, 1.5% and 5%, w/w), irradiated at 0, 30 and 60 kGy and pasted under pressure in a rheometer.

Malaria in children under-five: A comparison of risk factors in lakeshore and highland areas, Zomba district, Malawi.

Background: In Malawi, children under the age of five living in different geographical areas may experience different malaria risk factors. We compare the risk factors of malaria experienced by children under the age of five from Zomba district, who reside in lakeshore and highland areas.

Methods: We conducted a case control study of 765 caregivers, cases being children under-five who were diagnosed with malaria, and obtained matched controls from local health facilities and communities.

Assessing the sustainability of acid mine drainage (AMD) treatment in South Africa.

The environmental sustainability of acid mine drainage (AMD) treatment at semi-industrial scale is examined by means of the life cycle assessment (LCA) methodology. An integrated process which includes magnesite, lime, soda ash and CO bubbling treatment was employed to effectively treat, at semi-industrial scale, AMD originating from a coal mine in South Africa. Economic aspects are also discussed.

Seasonal variation of malaria cases in children aged less than 5 years old following weather change in Zomba district, Malawi.

Background: Malaria is seasonal and this may influence the number of children being treated as outpatients in hospitals. The objective of this study was to investigate the degree of seasonality in malaria in lakeshore and highland areas of Zomba district Malawi, and influence of climatic factors on incidence of malaria.

Methods: Secondary data on malaria surveillance numbers and dates of treatment of children <5 years of age (n = 374,246) were extracted from the Zomba health information system for the period 2012-2016, while data on climatic variables from 2012 to 2015 were obtained from meteorological department.

Ultra-sensitive and selective NH room temperature gas sensing induced by manganese-doped titanium dioxide nanoparticles.

The study of the fabrication of ultra-high sensitive and selective room temperature ammonia (NH) and nitrogen dioxide (NO) gas sensors remains an important scientific challenge in the gas sensing field. This is motivated by their harmful impact on the human health and environment. Therefore, herein, we report for the first time on the gas sensing properties of TiO nanoparticles doped with various concentrations of manganese (Mn) (1.

Isolation and characterisation of nanoparticles from tef and maize starch modified with stearic acid.

Nanoparticles were isolated from tef and maize starch modified with added stearic acid after pasting at 90°C for 130min. This was followed by thermo-stable alpha-amylase hydrolysis of the paste. The resultant residues were then characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), dynamic laser scattering particle size distribution (DLPSD), atomic force microscopy (AFM) and high-resolution transmission electron microscopy (HRTEM).

Life cycle assessment of facile microwave-assisted zinc oxide (ZnO) nanostructures.

The life cycle assessment of several zinc oxide (ZnO) nanostructures, fabricated by a facile microwave technique, is presented. Key synthesis parameters such as annealing temperature, varied from 90°C to 220°C, and microwave power, varied from 110W to 710W, are assessed. The effect of these parameters on both the structural characteristics and the environmental sustainability of the nanostructures is examined.

Photoluminescence Quenching and Enhanced Optical Conductivity of P3HT-Derived Ho(3+)-Doped ZnO Nanostructures.

In this article, we demonstrate the surface effect and optoelectronic properties of holmium (Ho(3+))-doped ZnO in P3HT polymer nanocomposite. We incorporated ZnO:Ho(3+) (0.5 mol% Ho) nanostructures in the pristine P3HT-conjugated polymer and systematically studied the effect of the nanostructures on the optical characteristics.

Influence of alkali metal cations on the thermal, mechanical and morphological properties of rectorite/chitosan bio-nanocomposite films.

The main theme of this work is to study the influence of ion-exchangeable alkali metal cations, such as: Li(+), Na(+), K(+), and Cs(+) on the thermal, mechanical and morphological properties. In this regard, a set of rectorite/chitosan (REC-CS) bio-nanocomposite films (BNCFs) was prepared by facile reaction of chitosan with ion-exchanged REC clay. The microstructure and morphology of BNCFs were investigated with XRD, TEM, SEM and AFM.

Development of a polyaniline-lignocellulose composite for optimal adsorption of Congo red.

A polyaniline lignocellulose composite (PLC) was synthesized and used in the removal of Congo red (CR) from aqueous solution. The adsorption process showed good fits to both the pseudo-second-order and pseudo-first-order models and the Redlich Peterson isotherm. Boundary layer diffusion was the rate-limiting step.

Single stage batch adsorber design for efficient Eosin yellow removal by polyaniline coated ligno-cellulose.

Polyaniline-coated lignin-based adsorbent (PLC) was synthesized and used for uptake of reactive dye eosin yellow (EY) from aqueous solution. The adsorption capability of the adsorbent was found to be more effective than the unmodified adsorbent (LC). In particular, the adsorption capability of the PLC was effective over a wider pH range.

Shape-selective dependence of room temperature ferromagnetism induced by hierarchical ZnO nanostructures.

We report on the room temperature ferromagnetism of various highly crystalline zinc oxide (ZnO) nanostructures, such as hexagonally shaped nanorods, nanocups, nanosamoosas, nanoplatelets, and hierarchical nano "flower-like" structures. These materials were synthesized in a shape-selective manner using simple microwave assisted hydrothermal synthesis. Thermogravimetric analyses demonstrated the as-synthesized ZnO nanostructures to be stable and of high purity.

Structure and properties of highly toughened biodegradable polylactide/ZnO biocomposite films.

Zinc oxide (ZnO) powder was investigated in terms of its use as filler in order to improve the inherent properties of PLA. Biocomposite films of PLA with different loadings of ZnO were prepared by solution casting method. Morphological analyses using SEM and POM showed that the ZnO particles were well dispersed at low ZnO loading, with starfish-like morphology.

Oxidative Coupling of 1-Naphthols over Noble and Base Metal Catalysts.

Bismuth-promoted platinum catalysts were tested for the oxidative coupling of 2- and 4-substituted 1-naphthols at different temperatures and ambient pressure. The principal final products are the 3,3'-substituted 1,1'-binaphthalenylidene-4,4'-diones and the 4,4'-substituted 2,2'-binaphthalenylidene-1,1'-diones, respectively. Hydrogen peroxide was used as the oxidant.

Toughening of biodegradable polylactide/poly(butylene succinate-co-adipate) blends via in situ reactive compatibilization.

Polylactide and poly(butylene succinate-co-adipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization of the blends occurred. Scanning electron micrographs showed not only a reduction in the dispersed-phase size with increased TPP content but also fibrillated links between the PLA and PBSA phases, signifying compatibilization.

Role of specific interfacial area in controlling properties of immiscible blends of biodegradable polylactide and poly[(butylene succinate)-co-adipate].

Binary blends of two biodegradable polymers: polylactide (PLA), which has high modulus and strength but is brittle, and poly[(butylene succinate)-co-adipate] (PBSA), which is flexible and tough, were prepared through batch melt mixing. The PLA/PBSA compositions were 100/0, 90/10, 70/30, 60/40, 50/50, 40/60, 30/70, 10/90, and 0/100. Fourier-transform infrared measurements revealed the absence of any chemical interaction between the two polymers, resulting in a phase-separated morphology as shown by scanning electron microscopy (SEM).

Ab initio studies of vacancies in (8,0) and (8,8) Single-walled carbon and boron nitride nanotubes.

A systematic study of vacancies in single-walled carbon nanotubes and boron nitride nanotubes was carried out. First principles calculations within the framework of density functional theory using the CASTEP code are used to optimize fully the geometries of the systems. The generalized gradient approximation is used for the exchange-correlation functional.

Occurrence of amylose-lipid complexes in teff and maize starch biphasic pastes.

The occurrence of amylose-lipid complexes was determined in maize and teff starch biphasic pastes i.e. peak viscosity pastes at short and prolonged pasting times.

Effect of nanoclay loading on the thermal and mechanical properties of biodegradable polylactide/poly[(butylene succinate)-co-adipate] blend composites.

Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0 to 9%. Small angle X-ray scattering patterns showed slightly better dispersion in PBSA than PLA, and there was a tendency of the silicate layers to delaminate in PBSA at low clay content.

Epitaxial deposition of silver ultra-fine nano-clusters on defect-free surfaces of HOPG-derived few-layer graphene in a UHV multi-chamber by in situ STM, ex situ XPS, and ab initio calculations.

The growth of three-dimensional ultra-fine spherical nano-particles of silver on few layers of graphene derived from highly oriented pyrolytic graphite in ultra-high vacuum were characterized using in situ scanning tunneling microscopy (STM) in conjunction with X-ray photoelectron spectroscopy. The energetics of the Ag clusters was determined by DFT simulations. The Ag clusters appeared spherical with size distribution averaging approximately 2 nm in diameter.