5,120 research outputs found

    Ultra High Strength Steels for Roll Formed Automotive Body in White

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    One of the more recent steel developments is the quenching and partitioning process, first proposed by Speer et al. in 2003 on developing 3rd generation advanced high-strength steel (AHSS). The quenching and partitioning (Q&P) process set a new way of producing martensitic steels with enhanced austenite levels, realised through controlled thermal treatments. The main objective of the so-called 3rd generation steels was to realise comparable properties to the 2nd generation but without high alloying additions. Generally, Q&P steels have remained within lab-scale environments, with only a small number of Q&P steels produced industrially. Q&P steels are produced either by a one-step or two-step process, and the re-heating mechanism for the two-step adds additional complexities when heat treating the material industrially. The Q&P steels developed and tested throughout this thesis have been designed to achieve the desired microstructural evolution whilst fitting in with Tata’s continuous annealing processing line (CAPL) capabilities. The CALPHAD approach using a combination of thermodynamics, kinetics, and phase transformation theory with software packages ThermoCalc and JMatPro has been successfully deployed to find novel Q&P steels. The research undertaken throughout this thesis has led to two novel Q&P steels, which can be produced on CAPL without making any infrastructure changes to the line. The two novel Q&P steels show an apparent reduction in hardness mismatch, illustrated visually and numerically after nano-indentation experiments. The properties realised after Q&P heat treatments on the C-Mn-Si alloy with 0.2 Wt.% C and the C-Mn-Si alloy with the small Cr addition is superior to the commercially available QP980/1180 steels by BaoSteel. Both novel alloys had comparable levels of elongation and hole expansion ratio to QP1180 but are substantially stronger with a > 320MPa increase in tensile stress. The heat treatment is also less complex as there is no requirement to heat the steel back up after quenching due to one-step quenching and partitioning being employed on the novel alloys

    Development of a microencapsulated functional ingredient formulated with the neurotransmitter GABA and the Lactiplantibacillus plantarum K16 produced through biotechnological processes

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    208 p.This PhD thesis has developed a new functional ingredient characterised by the novelty of combining anew L. plantarum K16 strain, isolated from the fermented food Kimchi, with the postbiotic metaboliteGABA produced by a fermentation process using agri-food by-products as substrate media. According tothe scientific literature, this functional ingredient intends to exert a beneficial effect on human health byacting in the intestine, guaranteeing a synergistic effect of the probiotic and GABA. The first step in thedeveloping process was focused on isolating and characterising a GABA-producer lactic acid strain fromfermented food kimchi. Then, am evaluation of the ability to produce GABA by this strain wasconducted, firstly, using commercial MRS broth where the effect of different parameters was assessed.Next, several agri-food by-products have been selected to be used as fermentation media due, on onehand, to their high environmental impact and, on the other hand, to their nutritional value for developinglow-cost culture media. Finally, one of this agri-food by-products was chosen to grow the isolatedbacteria and to produce GABA with it, for finally develop a microencapsulated functional ingredient.Tecnalia Research and Innovatio

    Management Controls for Sustainable Development: Evidence from a Thai Manufacturing Organisation

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    This thesis aims to empirically investigate the use of management controls in relation to sustainable development within an established manufacturing organisation in Thailand. Situated within the conflicts between formal motivators (e.g., performance measurement and reward systems) which call for economic rationalism and an informally cognitive responsibility for socio-ecological awareness and commitment (Ball and Milne, 2005; Milne, 1996), the existence of formal and informal management controls to support the sustainable development belief and their interplays are examined. An inductive research approach with Laughlin’s (1991) organisational change framework is drawn upon in the analysis of a single case study. The empirical evidence is collected through semi-structured interviews, non-participant observations and document analysis to investigate the organisation's sustainability discourse. This study makes important contributions to the extant social and environmental accounting literature, especially concerning management controls. Little research directs towards how organisations integrate their management controls with the sustainable development concept (Lueg and Radlach, 2016) due to its subjective and disputable nature (Ball and Milne, 2005; Gray, 2010; Milne, 1996). This research goes further to unveil the change journey in quantifiable and religious-based management controls within a Thai manufacturing organisation that encountered complex sustainability challenges. Furthermore, the sustainability concept has been integrated into corporate strategies, organisational culture and key capabilities for value-added activities and innovation. The internal and external disturbances were managed with proper caution and safeguards. The observed formal and informal management controls worked interdependently in line with the organisation’s core values (i.e., interpretive schemes – Laughlin, 1991). These control tools are shown to be built on “measure what can be managed” or achievable-based outcomes with support from multiple specialist work groups

    The near north and the far north: The Nikkei community in North Queensland, 1885-1946

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    Tianna Killoran researched the history of the Japanese community in north Queensland between 1885 and 1946. She found that this community of migrants made substantial contributions to the region's social, cultural, and economic life and played a significant role within Australia's transnational diplomatic and political connections during the twentieth century

    Land Use and Land Cover Mapping in a Changing World

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    It is increasingly being recognized that land use and land cover changes driven by anthropogenic pressures are impacting terrestrial and aquatic ecosystems and their services, human society, and human livelihoods and well-being. This Special Issue contains 12 original papers covering various issues related to land use and land use changes in various parts of the world (see references), with the purpose of providing a forum to exchange ideas and progress in related areas. Research topics include land use targets, dynamic modelling and mapping using satellite images, pressures from energy production, deforestation, impacts on ecosystem services, aboveground biomass evaluation, and investigations on libraries of legends and classification systems

    Trend assessment of changing climate patterns over the major agro-climatic zones of Sindh and Punjab

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    The agriculture sector, due to its significant dependence on climate patterns and water availability, is highly vulnerable to changing climate patterns. Pakistan is an agrarian economy with 30% of its land area under cultivation and 93% of its water resources being utilized for agricultural production. Therefore, the changing climate patterns may adversely affect the agriculture and water resources of the country. This study was conducted to assess the climate variations over the major agro-climatic zones of Sindh and Punjab, which serve as an important hub for the production of major food and cash crops in Pakistan. For this purpose, the climate data of 21 stations were analyzed using the Mann–Kendall test and Sen's slope estimator method for the period 1990–2022. The results obtained from the analysis revealed that, in Sindh, the mean annual temperature rose by ~0.1 to 1.4°C, with ~0.1 to 1.2°C in cotton-wheat Sindh and 0.8 to 1.4°C in rice-other Sindh during the study period. Similarly, in Punjab, the mean annual temperature increased by ~0.1 to 1.0°C, with 0.6 to 0.9°C in cotton-wheat Punjab and 0.2 to 0.6°C in rainfed Punjab. Seasonally, warming was found to be highest during the spring season. The precipitation analysis showed a rising annual precipitation trend in Sindh (+30 to +60 mm) and Punjab (+100 to 300 mm), while the monsoon precipitation increased by ~50 to 200 mm. For winter precipitation, an upward trend was found in mixed Punjab, while the remaining stations showed a declining pattern. Conclusively, the warming temperatures as found in the analysis may result in increased irrigation requirements, soil moisture desiccation, and wilting of crops, ultimately leading to low crop yield and threatening the livelihoods of local farmers. On the other hand, the increasing precipitation may favor national agriculture in terms of less freshwater withdrawals. However, it may also result in increased rainfall-induced floods inundating the crop fields and causing water logging and soil salinization. The study outcomes comprehensively highlighted the prevailing climate trends over the important agro-climatic zones of Pakistan, which may aid in devising an effective climate change adaptation and mitigation strategy to ensure the state of water and food security in the country

    Printed Supercapacitors for Energy Storage and Functional Applications, Modeling, Analysis, and Integration

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    Supercapacitors (SCs), also known as ultracapacitors or electrochemical double-layer capacitors (EDLCs), have emerged as a remarkable class of energy storage devices that bridge the gap between conventional capacitors and batteries. These devices exhibit exceptional power density and long lifecycle, making them well-suited for a wide range of applications, from powering portable electronics to enabling rapid energy storage and release in various industrial systems. Unlike batteries, SCs store energy through the physical separation of charges at the electrode-electrolyte interface, leading to rapid charging and discharging capabilities. However, SCs are not without their challenges, notably leakage current and self-discharge, which can impact their long-term performance and practical utility. As the demand for energy-efficient and responsive power solutions intensifies, a thorough understanding of SCs’ behavior, coupled with accurate modeling techniques, becomes imperative. This thesis delves into this intricate realm, offering insights, models, and practical applications that collectively contribute to harnessing the potential of SCs across diverse domains. In the realm of energy storage and power management, this thesis presents a cohesive exploration of SCs’ behavior and its practical implications through a series of five interrelated research papers. Focusing on the context of charging and discharging within series-connected SC modules under varying load conditions, the research advances an innovative exponential model that elegantly captures complex behaviors with less than 4% simulation error over extended time frames (31 days). The initial study introduces an improved exponential equivalent circuit model (ECM) that elegantly characterizes the charging and discharging dynamics of series-connected SC modules. Leveraging a single-variable leakage resistance (VLR) approach, the model adeptly accounts for diverse self-discharge mechanisms. Unlike existing literature ECMs, this ECM’s simplicity and accuracy render it suitable for real-world applications in both short and long terms. The investigation extends to the modeling of multiple SC energy storage modules, providing insights into the behavior of SCs within varying configurations. Expanding into the domain of Internet of Things (IoT) applications, the research highlights the significance of energy storage devices for wireless sensor nodes. Acknowledging the limitations of traditional batteries, the study advocates for SCs as a viable solution. A refined exponential model is then proposed as a novel approach to predict the discharge behavior of disposable printed flexible SCs, ensuring concordance with experimental findings. This approach involves employing an innovative method to model the non-linearity of self-discharge in printed SCs, effectively capturing this phenomenon. This ECM’s adaptability and alignment with measured self-discharge results offer a promising avenue for optimal IoT device performance. Confronting the challenges of leakage current and self-discharge in SCs, the thesis presents a comprehensive framework. By proposing practical exponential ECMs, the study encapsulates nonlinear leakage and self-discharge phenomena. The empirical basis of these ECMs allows accurate prediction of discharge behaviors over extended periods, thereby holding potential for widespread practical application. A linear correlation was identified among the variables governing the exponential function of the equivalent parallel resistance (EPR) within the SC’s ECMs and the capacitance. The precision of the proposed ECMs was substantiated over an extended duration of 31 days, employing a diverse array of four distinct methodologies. The thesis also takes a statistical turn by conducting a meticulous analysis of experimental parameters across printed SCs. Employing established ECMs, the research unveils statistical distributions and correlations, empowering safer operation, and more informed decision-making. Monte Carlo simulation technique unveils the long-term performance of SCs, offering insights into consistency and aiding in risk assessment. The conducted statistical analysis has revealed a normal distribution pattern for all the parameters characterizing the printed SCs. Additionally, this thesis presents a methodology to ascertain the upper limit of potential standard deviation (std) in capacitance values across SCs within a module, aiming to ensure the seamless operation of the module without encountering malfunctions. Furthermore, an observed linear correlation has been established between the maximum potential std of capacitance values among SCs and the cumulative voltage stored within the module. Finally, the exploration expands to the activation of irreversible visual indicators (IVIs) through printed SCs, highlighting the potential of diverse monomer systems. The interplay of activation potential, coloration efficiency, and initial voltage underscores the feasibility of fully activating IVIs through series-connected SCs. In summary, this thesis intricately weaves together five research papers to construct a comprehensive narrative about the behavior, modeling, and application of SCs. From exponential models to statistical analyses and practical implementations, this work contributes to the broader understanding of SC dynamics and their potential within contemporary energy storage systems and IoT applications. The results-driven approach solidifies SCs' impact as a versatile energy storage device, emphasizing realworld performance, and evidence-based decisions

    Cooperative Governance Moderates Liquidity’s Relationship with Credit Risk, Working Capital, and Internal Control

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    This research, which is based on a survey of savings and credit unions and is funded by the Directorate of Cooperatives and Small and Medium Enterprises, aims to identify and assess how credit risk, working capital, and internal control affect liquidity. Secondary data from the Ministry of Cooperatives and Small and Medium Enterprises served as the foundation for this study's data. The quantitative research methodology was employed in this study. The findings of this study demonstrate that internal control, working capital, and credit risk all significantly impact liquidity. Working capital has no impact on liquidity, internal control positively impacts liquidity, and the credit risk variable has a partially negative impact on liquidity. Liquidity is lessened by collaborative governance's reduction of credit risk. Working capital's negative effects on liquidity are reduced by collaborative management. The effect of internal controls on liquidity is not lessened by collaborative management. Keywords: Credit Risk, Working Capital, Internal Control, Liquidity, Cooperative Governance. DOI: 10.7176/RJFA/14-16-02 Publication date:August 31st 202
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