Emulsifiers affect the texture of pastes made from fermented and non-fermented cassava flours†

The effects of glycerol monostearate (GMS) and sodium steroyl lactylate (SSL) on the rheological properties of native, naturally fermented (NF) and mixed culture fermented (MCF) cassava flour pastes were measured using instrumental texture profile analysis (TPA) and by finger cohesiveness (difficulty in separation). Fermentation reduced the TPA parameters, hardness, cohesiveness and gumminess, but not springiness/elasticity. These were reduced further when either GMS or SSL were incorporated into the pastes. Pastes made from native and naturally fermented flours were scored by a Cameroonian sensory panel as difficult to separate, whereas scores for native and fermented flour pastes treated with 1% or more of GMS or SSL were easy to separate. Increased internal stability of the cassava flour starch granules was suggested as the cause of the effects.     

Transmission of 160-Gb/s Modified Manchester modulation over WDM system

The paper examines the performance of Modified Manchester (MM) modulation scheme over wavelength division multiplexing (WDM) in high-speed optical communication links. The MM as a new modulation technique has a narrow spectral width compared to conventional Manchester coding, which allows its implementation in WDM systems beneficial. In this study, the performance characteristics of MM and conventional Manchester modulation formats are assessed in WDM system at 10 Gb/s bitrate for each channel, for the least allowable channel spacing as well as tolerance to chromatic dispersion (CD). It is revealed from the results of simulation that MM performs meaningfully well in comparison with conventional Manchester in terms of tolerance against narrow optical filtering, spectral efficiency, which is improved by 32% and CD tolerance, which is improved by +100 ps/nm. Sixteen wavelength channels (16 × 10 Gb/s) are modulated to provide 160 Gb/s data capacity, which was transmitted successfully over 224 km standard single mode fibre (SSMF) using MM while the conventional Manchester only covered about 157 km.     

Application of strategic fuzzy games to wage increase negotiation and decision problems

We propose a flexible decision support scheme which could be used in managing the wage negotiation between employers and employees. This scheme uses fuzzy inference systems and game theory concepts in arriving at decisions on future wage increase which could be more mutually agreeable. For example, rather than specifying 5% yearly increase of wages, we propose that the uncertain factors which are mostly difficult to predict and that could affect wage decisions need to be taken into consideration by the wage formula. These include business revenues or (profit), inflation rate, number of competitors, cost of production, and other uncertain factors that may affect business operations. The accuracy of the fuzzy rule base and the game strategies will help to mitigate the adverse effects that a business may suffer from these uncertain factors. Based on our scheme, we propose that employers and employees should calculate their future wage by using a fuzzy rule base and strategies that take into consideration these uncertain variables. The proposed approach is illustrated with a case study and the procedure and methodology may be easily implemented by business organizations in their wage bargaining and decision processes.     

High-Performance Vitrimeric Benzoxazines for Sustainable Advanced Materials: Design,Synthesis, and Applications

Polybenzoxazines are high-performance materials capable of replacing conventional thermosets such as phenolics, epoxies, and bismaleimides in composites manufacturing due to their excellent thermomechanical and chemical behavior. Their versatility and compatibility with biobased precursors make them an attractive option as composite matrices. Like other thermosets, polybenzoxazines are not recyclable and cannot be reprocessed. Incorporating dynamic bonds in benzoxazine monomers can produce vitrimeric polybenzoxazines, which can potentially overcome this limitation and can be tuned to exhibit smart functionalities such as self-healing and shape memory. Dynamic bond exchange mechanisms for vitrimer development such as transesterification, imine bond, disulfide exchange, transamination, transcarbamoylation, transalkylation, olefin metathesis, transcarbonation, siloxane-silanol exchange, boronic ester, silyl ether exchange, and dioxaborolane metathesis are potentially applicable to benzoxazine chemistry, with disulfide bond and transesterification having successfully vitrimerized benzoxazines with topological transitions at −8.5 and 88 °C, respectively. Benzoxazine vitrimers featuring glass transitions of 193, 224, and 222–236 °C are now known. These place polybenzoxazines at the forefront of the development of reprocessable and recyclable thermosetting polymers and composite matrices.     

Effects of fungicide residues on the physico-chemical characteristics of soils of a major cocoa-producing area of Nigeria

The effects of copper-based fungicide residues on some physico-chemical properties of soils in some cocoa-producing areas of Nigeria were investigated. The results show that the fungicide residues cause significant increases in the soil pH, organic matter and copper concentrations while lowering the concentrations of inorganic nitrogen, available phosphorus, exchangeable potassium and sodium. Slight increases were also observed for the cation exchange capacity (CEC) and exchangeable Ca2+ and Mg2+ but there are no significant changes in the Zn, Fe and Mn concentrations with fungicide treatment. It is concluded that the copper-based fungicide residues predispose the soils to nitrogen, phosphorus and potassium (N, P and K) deficiencies and perhaps copper toxicity if not properly managed.     

The role of the Kenya Agricultural Research Institute (KARI) in the attainment of household food security in Kenya: A policy and organizational review

The Kenya Agricultural Research Institute (KARI) is a government organization mandated to conduct research into, among others, crop and livestock production and marketing. In 2009, it launched a new strategic plan for the period 2009?C2014, together with its implementation framework. This strategic plan aims to position KARI as a facilitator of growth in the agricultural sector in order to enable an average growth rate of 7?% per year over the next 5?years, as stipulated in the Kenya Vision 2030 policy. This paper reviews KARI??s new strategic plan within the context of recent policy reforms at national, regional and global levels. It specifically examines the strategy in the context of Vision 2030, the Kenya Agricultural Sector Development Strategy (ASDS), the Comprehensive Africa Agriculture Development Program (CAADP), and the Millennium Development Goals. The paper then discusses KARI??s newly adopted Agricultural Product Value Chain (APVC) approach, which is expected to position KARI strategically as a key player within the National Agricultural Research System (NARS). It also highlights progress in the implementation of the new strategic plan and APVC approach with specific emphasis on partnerships, markets and gender as key focus areas and the implications of these on food security in Kenya.     

Nitrogen dynamics in maize-based agroforestry systems as affected by landscape position in southern Malawi

In Malawi, agroforestry is very promising for N replenishment; however, there are still large variations in the performance of these agroforestry technologies on farmers’ fields. A study was conducted on-farm to determine the influence of three landscape positions on N dynamics in maize (Zea mays L.)-based agroforestry systems. The agroforestry systems were relay fallow using Sesbania sesban (L.) Merr or Tephrosia vogelii (Hook F.), simultaneous fallow using Gliricidia sepium(Jacq.) Walp., and maize without trees as a control. Sesbania was superior to other systems in the bottom slope, producing the highest tree biomass (1,861 kg ha⁻¹), whereas, gliricidia gave the highest tree biomass production in the mid-slope (2,147 kg ha⁻¹) and upper slope (1,690 kg ha⁻¹). Preseason inorganic N, maize flag leaf N concentration, maize total N uptake and maize yields followed a similar trend to tree biomass production with tree-based cropping systems exhibiting higher productivity (P < 0.05) than the cropping systems without trees. Nitrogen leaching from gliricidia agroforestry systems was lower than in the other agroforestry systems across all landscape positions as evidenced by 17% lower amounts (P < 0.05) of inorganic N adsorbed to ionic exchange resin membranes at 60 cm soil depth most likely due to the permanent root system of gliricidia. The difference between δ¹⁵N values of the trees and the soil did not change between landscape positions suggesting that if the leguminous trees fixed atmospheric N₂, the proportion of total N uptake was identical at all locations. We concluded that landscape positions have a significant effect on tree performance with sesbania remarkably adapted to the bottom slope, gliricidia to the mid-slopes and tephrosia fairing similar in both the bottom slope and mid-slopes.     

Urban green space dynamics and socio-environmental inequity: multi-resolution and spatiotemporal data analysis of Kumasi,Ghana

Urban green spaces (UGS) are crucial for urban sustainability and resilience to environmental vulnerabilities but are often relegated in cities in the global south. This article analysed the spatio-temporal change, composition, extent, and distributional inequities associated with UGS in Kumasi, Ghana. Spatial techniques and Gini index were combined in the assessment. Kumasi UGS coverage is currently 33% but declined fourfold faster in recent years (2009–2014) than previously (1986–2002). The overall accuracy of the change maps: 1986–2014 and 2009–2014 were, respectively, 0.96 ± 0.02 and 0.97 ± 0.02. The Shannon entropy for built-up sprawl in 1986 and 2014 were 0.80 and 0.99, respectively. The UGS area per capita for 2009 (R² = 0.50, p = 0.049) and 2014 (R² = 0.53, p = 0.0398) were moderately correlated with socioeconomic conditions of sub-metropolises. The Gini coefficient for both vegetation and tree cover was 0.26. UGS cover is plummeting and somewhat unevenly distributed across Kumasi. Strategic planning for UGS can ensure ample availability, equity in access, and resilience to climate-related vulnerabilities.     

An overview of RF energy harvesting and information transmission in cooperative communication networks

Telecommunication Systems - Wireless energy harvesting and information transfer (WEHIT) is a new paradigm in cooperative communication networks. WEHIT enables energy constrained cooperative...