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Transformative rural smallholder agriculture addressing biophysical constraints requires farmer-led innovations for increased technology adoption. Following the need to further intensify the cereal push-pull technology (PPT) for pest and weed control through integration with vegetables, we conducted surveys to determine suitable vegetables across three different counties in Kenya namely Homabay, Siaya, and Trans-Nzoia. Farming in these areas is predominantly maize based and introducing vegetables to the system will improve household food and nutritional security, together with income. A systematic random sampling method was used to sample a total of 124 smallholder farmers who were interviewed during field days where farmer awareness of technology was mobilised. Descriptive results showed kale (47%) and black nightshade (30%) were the most preferred high-value vegetables for integration into push-pull plots in these regions. This was followed by cowpea (15%), onion (6%) and tomato (2%) underlying the wide range of farmer preferences and priorities. There were also gender differences in vegetable preferences with men preferring capital intensive and high value vegetables, while women preferred traditional vegetables. Results from multinomial logit model revealed that age of the farmer, education level, gender, and farming experience were determinants of smallholder farmers' vegetable preferences for integration into the PPT plots. The contribution of these determinants to farmer preferences varied across different vegetables where the contribution of the market value of the vegetable in selection diminished with while the effect of farmers' age. Overall, male farmers preferred capital-intensive and market-oriented vegetables in compared to their female counterparts. We conclude that gender and geographic location play a pivotal role in farmers' crop selection for integration in the PPT. Targeted awareness creation pathways accounting for these factors will be critical for wider adoption of the PPT. [ABSTRACT FROM AUTHOR]

We report the structural and nonlinear behavior of Sn1−x−yZnxMyOz varistors with x = 0.00, 0.50, y = 0.00, 0.25 and M = Fe, Co, Ni and Mn. The crystallite and grain sizes and porosity of SnO2 are decreased by Zn doping, followed by a further decrease by (Zn + M) co-substitution. The breakdown field (EB), nonlinear coefficient (α), leakage current (IK) and residual voltage (Kr) of SnO2 are respectively 333.35 V/cm, 5.6, 900 μA/cm2 and 5.32. When SnO2 was substituted by Zn, IK and Kr are decreased to 816 μA/cm2 and 3.62, whereas EB and α are increased to 666.67 and 11.48. The EB and α values are increased by co-substitution in the SnZnMn sample, whereas IK and Kr are decreased. Rather than containing many elements and compounds, the current varistors are based on only two well-known ions co-substituted into SnO2. These findings are discussed in terms of the oxygen vacancies. [ABSTRACT FROM AUTHOR]

Tetraiodomercurate (Ag2HgI4) nanostructures were grown using facile low temperature chemical synthesis technique successfully. As synthesized nanostructures were examined using X-ray diffraction, UV–Vis and Raman spectroscopy. X-ray diffraction pattern of sample reveals pure tetragonal β phase Ag2HgI4 nanostructure growth. The preferred orientation of grown nanostructures was observed along (112) plane and lattice constant was found a = b = 6.31858 Å and c = 12.60247 Å. Raman spectra of nanostructures showed vibrational modes at ~ 60 cm−1, 107 cm−1,151 cm−1, and 268 cm−1 that is confirms growth of pure phase Ag2HgI4 nanostructures. Surface morphology of nanostructures was analyzed using scanning electron microscopy which showed algae type nanostructures in bundles form. Optical bandgap of nanostructures was determined using diffuse reflectance spectra which is obtained in range of 2.45 eV. Dielectric properties of nanostructure were explored as a function of frequency. A significant variation in dielectric constant was observed with frequency, it reduced to about half at high frequency. In addition, optoelectronic performance of nanostructures was also studied. Optoelectronic parameters such as external quantum efficiency (EQE), responsivity and specific detectivity of nanostructures were found to be ~ 27–145, 0.11–0.6 A/W and 2.0 × 1010–1.07 × 1011 Jones; respectively. [ABSTRACT FROM AUTHOR]

We report here the structural, FTIR, optical, mechanical, and magnetic properties of Zn1−xFexO with various Fe nanopowder additions (0.00 ≤ x ≤ 0.30). The wurtzite structure and compressive stress are clearly conformed in all samples. Further, the lattice constants, crystallite size, porosity, strains, grain size, Debye temperature, and elastic modulus are increased as x increases to 0.05, followed by a decrease at x = 0.30, but they are higher than those of ZnO. Interestingly, two electronic transitions were observed for all samples corresponding to two values of energy gaps, Eg1 and Eg2. They were decreased from 3.25 and 3.72 eV to 3.00 and 3.60 eV, respectively. In contrast, an enhancement of the lattice constant ϵL, the density of charge carriers (N/m*), and the optical and electrical conductivities as x increases was obtained. For example, ϵL and charge carriers density (N/m*) for x = 0.30 doped sample are, respectively, 10 and 15 times more than those of ZnO. The refractive index (n) increases as x is increased, and a good correlation between n and Eg was obtained. Other parameters, such as the dissipation factor, surface and bulk loss functions, were also controlled by the variation of x. The non-linear optical parameters were also increased by increasing x, indicating not only the interesting optical properties of these materials but also the possibility of their optoelectronic applications. The Vickers hardness Hv is increased by increasing x to 0.30 and applying load to 9.8 N. In contrast, the surface energy γ, elastic indentation de, and resistance pressure decrease as x increases to 0.10, followed by an increase at x = 0.30. A noticeable ferromagnetic behavior with evaluated magnetization parameters is clearly obtained for the x = 0.10 sample. The saturation magnetization Ms is about 250 times greater than that of ZnO, which supports the room temperature ferromagnetic (RTFM) for the Fe-doped sample. These findings indicate that the addition of Fe as nanopowder to ZnO is promising for altering plastic flow region, optoelectronic, high-power operating and spintronic devices, which highlights the present investigation. [ABSTRACT FROM AUTHOR]

This study examined the impact of push-pull technology (PPT) on the nutritional status of children aged 1-12 years. Non-push-pull (NPPT) farmers were used as a control group to establish a comparative model for this study. It determined household production, consumption, and surpluses, comparing the PPT adopters to the nonadopters; found out the incomes and food expenditures from farm products; found out the household dietary diversity scores; and finally found the nutritional status of the two household groups. A six faceted household-level metrics was employed. A sample of 216 households that registered 326 children was derived. This study was conducted in western Kenya: Busia, Butere, Siaya, Vihiga, Kisumu, and Migori. In this study 53% were male and 47% female from the households assessed. Households with married couples were 87.5%, 1.9% were single parents, 0.5% were separated and 10.2% were widowed. Averagely, 7.20 members came from PPT households, while 6.99 were from NPPT households. Each household (both PPT and NPPT) had an average number of three children. The study further showed that 88 households of PPT had their income sources from farm products sales as NPPT had 67 households on the same. Income was averagely 126.29US$ for PPT and 91US$ for NPPT. Push-pull households had 1303 Kgs of farm production while NPPT had 578 Kgs per year. The scale of agriculture to nutrition benefits recorded 8.7/10 for PPT and 7.14/10 for NPPT. Finally, PPT registered 12% of ≥+2SD, 84% of between -2 and > +2SD and 4% of ≥ -2SD for children under five years and 3% of ≥+2SD, 89% of between -2 and > +2SD and 8% of ≥ -2SD for children aged between 6 to 12 years. Non Push-pull households controversially registered 3% of ≥+2SD, 61% of between -2 and > +2SD and 36% of ≥ -2SD for children less than five years and 3% of ≥+2SD, 53% of between -2 and > +2SD and 44% of ≥ 2SD for children aged between 6 to 12 years. In conclusion, PPT is proven as an agricultural intervention that has enhanced nutritional improvement. [ABSTRACT FROM AUTHOR]