Narrow Results

The study combines the research domains of strategic management and corporate innovation by examining the impact of strategic management practices on entrepreneurial orientation (EO). Recognising the importance of internal business processes that enable firm entrepreneurial behaviour, it is hypothesised that higher levels of EO are positively associated with the strategic management practices of (1) locus of planning, (2) scanning intensity, (3) planning flexibility, (4) planning horizon, and (5) strategy and financial control attributes. Empirical testing takes place in an under-researched emerging market context on a sample of 219 financial and business services firms. The results provide support for the positive impact that the different strategic management practices have on EO. A practical consideration is for managers to leverage the strategic management practices so that the firm's position on the conservative-entrepreneurial continuum is increased by its propensity to be innovative, proactive, and be willing to take risks when confronted by uncertainty.

In this paper, we formulate and analyze a mathematical model to investigate the transmission dynamics of tomato bacterial wilt disease (TBWD) in Mukono district, Uganda. We derive the basic reproduction number $R_0$ and prove the existence of a disease-free equilibrium point which is globally stable if $R_0<1$ and an endemic equilibrium which exists if $R_0>1$. Model parameters are estimated using the Markov Chain Monte Carlo (MCMC) methods and robustness tested. The model parameters were observed to be identifiable. Numerical simulations show that soil solarization and sensitization of farmers can help to eliminate the disease in Uganda. A modified tomato bacterial wilt model with control terms is formulated.

The Absorption Refrigeration Cycle Turbine Inlet Conditioning (ARCTIC) system can chill the inlet air of the turbine to maintain optimum turbine performance at all ambient temperatures. However, turbine characteristics and bell-mouth icing concerns impose a minimum temperature limitation on the chilled air. Performance guarantees may also require maintaining the inlet air temperature within a narrow range throughout the year. These considerations require accurate prediction of the chilling coil performance over a wide range of operating conditions and the development of a robust controls strategy. A modified wet-surface model is used to model the chilling coil performance. The application of the model to a 2110kW (600 RT) ARCTIC providing inlet air chilling for a MARS 100 turbine is considered. A control strategy is developed to maintain the inlet air temperature at the desired set point with varying ambient temperatures and chilling loads. The TIAC controls help maintain the inlet air temperature at 7.22^∘C to maximize turbine capacity and efficiency during most of the hot/warm days and accommodates 100% turndown. Additional safety measures are incorporated to prevent bell-mouth icing.

Ambient conditions greatly affect the combustion turbine performance. The Absorption Refrigeration Cycle Turbine Inlet Chilling (ARCTIC) system can chill the inlet air of the turbine to maintain optimum performance at all ambient temperatures. However, turbine characteristics, bell-mouth icing concerns, economics and performance guarantees require maintaining the inlet air temperature within a narrow range throughout the year. These considerations require strict control of the Turbine Inlet Air Chilling (TIAC) coil performance over a wide range of operating conditions. This paper describes the field performance and control of the chilling coil for a Mars 100 turbine. The controls logic had been developed from previously published empirical model of the chilling coil and model of the chilling loop performance at the various ambient conditions. Since commissioning at the end of summer 2020, the ARCTIC has provided inlet air chilling over a range of ambient conditions. Typically, the inlet air is maintained at 7.2^∘C (45^∘F) by controlling the TIAC chilled water flow rate and temperature. On cooler days, if the inlet air temperature drops to 5.6^∘C (42^∘F) the chilled water pump turns OFF automatically to prevent bell-mouth icing. Thus, the chiller accommodates chilling load variations down to zero load. On colder days, the ARCTIC continues operating till the ambient temperature drops below 1.7^∘C (35^∘F) and then turns OFF. The chiller turns back ON when the 8 h average inlet air temperature exceeds 10^∘C (50^∘F). These parameters can be adjusted remotely by the operator and help maintain performance guarantees while minimizing chiller cycling. Quasi-steady state data were analyzed to quantify the chilling load and coil performance over a range of operating conditions.

Humans have reorganised and expanded earthworm communities across the globe. Earthworm invasions are associated with altered soil properties and nutrient cycling, with cascading effects on soil organisms and plants. The negative impacts of invasive earthworms are widely recognised, but management options are limited. Prevention through regulation and education is essential. Best practices to avoid earthworm introduction at global and local scales include border controls and regulations. Eradication at the early stages of invasion is possible locally, but once populations increase, containment and adaptation constitute the only feasible options. Control methods for earthworms include mechanical, chemical, and biological approaches. Methods are in different stages of development, vary in their efficacy, and many pose significant non-target effects that need to be considered. Once earthworms are established, emphasis should be placed on protecting vulnerable habitats, reducing impacts and earthworm abundance by managing co-occurring stressors, and investing in restoration with tolerant species. Public education and involvement are essential at all stages of earthworm invasion. Research to understand the impacts of invasive earthworms and their response to management under changing conditions is necessary to manage invasive earthworms effectively.

The complexity of the novel integrated heating system's design requires a new control strategy that will not oppose the system functions while, at the same time, providing high efficiency, low emissions and optimal system performance. This paper will present a fuzzy logic control strategy that can be applied to integrated heating systems and a neural networks approach to hot water draw predictions. This approach differs from the conventional strategy since it takes into consideration a number of external and internal factors influencing the system's performance as well as the homeowner's distinct habits.