Portfolio Of Sources Research Articles

Nuclear energy in Bangladesh: A SWOT analysis

Zero-emission energy sources like nuclear energy are taken into account worldwide due to the negative environmental consequences of fossil fuels and their limited availability over the years. Bangladesh plans to add nuclear energy to its portfolio of energy sources by 2024. Under the scope of this study, the country's nuclear energy strategy was looked at in terms of its strengths, weaknesses, opportunities, and threats. This was done using a method known as SWOT analysis. It has come to light that Bangladesh has a significant number of aspects in terms of strengths as well as opportunities that make the possibility of doing an investment in the construction of a nuclear power plant a realistic choice. Difficulties such as a culture of poor maintenance, financial burden, lack of skilled manpower, a poor power grid, radioactive waste management, and corruption are the weaknesses and threats to the effective construction, operation, and maintenance activities of the nuclear power plant in Bangladesh. By mitigating these difficult aspects, Bangladesh's journey to adopt nuclear energy can be more smooth.

Genome-scale metabolic model of the versatile bacterium Paracoccus denitrificans Pd1222.

A genome scale metabolic model of the bacterium Paracoccus denitrificans has been constructed. The model containing 972 metabolic genes, 1,371 reactions, and 1,388 unique metabolites has been reconstructed. The model was used to carry out quantitative predictions of biomass yields on 10 different carbon sources under aerobic conditions. Yields on C1 compounds suggest that formate is oxidized by a formate dehydrogenase O, which uses ubiquinone as redox co-factor. The model also predicted the threshold methanol/mannitol uptake ratio, above which ribulose biphosphate carboxylase has to be expressed in order to optimize biomass yields. Biomass yields on acetate, formate, and succinate, when NO3- is used as electron acceptor, were also predicted correctly. The model reconstruction revealed the capability of P. denitrificans to grow on several non-conventional substrates such as adipic acid, 1,4-butanediol, 1,3-butanediol, and ethylene glycol. The capacity to grow on these substrates was tested experimentally, and the experimental biomass yields on these substrates were accurately predicted by the model.IMPORTANCEParacoccus denitrificans has been broadly used as a model denitrifying organism. It grows on a large portfolio of carbon sources, under aerobic and anoxic conditions. These characteristics, together with its amenability to genetic manipulations, make P. denitrificans a promising cell factory for industrial biotechnology. This paper presents and validates the first functional genome-scale metabolic model for P. denitrificans, which is a key tool to enable P. denitrificans as a platform for metabolic engineering and industrial biotechnology. Optimization of the biomass yield led to accurate predictions in a broad scope of substrates.

Crustal response to water loads and expansion of triggered seismicity around the Xiluodu Reservoir, Southwest China

<p>The transition to low-carbon energy generation requires a diverse portfolio of energy sources. Large hydropower stations play a crucial role in providing eco-friendly energy but can lead to crustal deformation and seismic activity due to reservoir impoundment and discharge. The mechanism behind how impoundment-induced deformation influences reservoir-triggered seismicity remains unclear. We investigate this at the world��s 4<sup>th</sup> largest hydropower station in Xiluodu, China, using interdisciplinary analyses of relocated earthquakes, geodetic data, and numerical simulations. Geodetic observations confirm both a linear elastic response to hydrologic loading and the transition towards a relaxed and flexural response. Notably, approximately 81% of the earthquakes since impoundment occurred within ~15 km of the subsidence center. These events temporally relate to rapid hydrologic loading/unloading periods, with their spatiotemporal outward migration potentially caused by viscous relaxation of load stresses in the lower crust and upper mantle. The reservoir-induced flexural deformation and subsequent viscous relaxation may control the distribution and expansion of triggered seismicity. This research highlights the urgent need to enhance geohazard monitoring efforts around the subsidence center and emphasizes the vital importance of carefully considering this factor during the construction of large reservoirs to mitigate potential seismic risks.</p>

Resilient relief supply planning using an integrated procurement-warehousing model under supply disruption

In order to mitigate the damage caused by natural disasters, appropriate relief supply planning is essential for humanitarian relief chains. This paper develops a resilient relief supply plan by formulating a novel integrated procurement-warehousing model under supply disruption via utilizing a portfolio of long-term contracts between a relief organization, multiple main and backup suppliers, and a third party who provides warehousing service. By using a portfolio of supply sources, a tailored two-stage scenario-based stochastic programming model is presented for determining an integrated relief procurement-warehousing plan. The plan includes (1) a number of multi-period quantity flexibility contracts with the main suppliers at pre-disaster, for prepositioning of relief supplies while ensuring to receive extra required amounts at post-disaster, (2) a number of dynamic option contracts with backup suppliers for decreasing the impacts of risks pertaining to the demand uncertainty and supply disruption at the main suppliers, and (3) a multi-period warehousing contract with a third party which allows the relief organization to adjust the required storage space in different periods to avoid extra cost pertaining to the storage space surplus/shortage. An effective differential evolution (DE) solution algorithm is also devised to solve the real scale instances efficiently. Applicability of the proposed model is illustrated by a real case study and useful managerial insights are extracted through conducting several sensitivity analyses.

Which clean energy contributes better for growth? – dynamic panel analysis of heterogeneous impacts of individual renewable sources on economic growth

The impact of renewable energy on economic growth has been controversial and the possible reason for this is that renewable energy is aggregation of sources with heterogeneous characteristics and different countries have different portfolio of renewable sources depending on their climate condition and technology maturity. This study examines the relationship between renewable energy sources such as solar, wind and bio energy and economic growth in 89 countries. For methodology, this paper adopted Islam's growth equation and performed Dynamic Panel Analysis based on Arellano-Bond GMM methodology. In addition to whole sample analysis, a sub-group analysis is performed between OECD and non-OECD countries, and between energy-importing and energy-exporting countries to examine how the relationship is affected by country's capital accumulation, technology maturity, energy cost, and energy security. The result shows that individual sources have the U-shaped relationships with growth, but the turning points where negative relationship changes to positive vary for different sources. For sub-group analysis, the U-shaped relationship was significant only in OECD countries and energy-importing countries. This shows that high technology development and capital accumulation of OECD countries and high energy cost and vulnerability to international energy market of energy-importing countries makes renewable sources more beneficial to economic growth.

Sourcing portfolio diversity in new product development: Antecedents and performance implications

This paper examines the antecedents and performance outcomes of sourcing portfolio diversity in firms’ new product development (NPD). Sourcing portfolio diversity measures the degree to which a firm uses multiple sourcing choices along both organizational and geographic dimensions including domestic in-house sourcing, domestic outsourcing, captive offshoring, and offshore outsourcing. We extend transaction cost economics (TCE) to the portfolio level of analysis and predict that sourcing portfolio diversity in NPD is driven by heterogeneity in two transactional characteristics—technological application diversity, reflecting asset specificity, and variance in project-stage uncertainty. We also argue that the positive effect of sourcing portfolio diversity on firms’ financial performance is driven by aligning sourcing portfolio configuration with the sources of transactional heterogeneity, increased strategic agility, and complementarities between individual sourcing choices. Our empirical study of NPD in the bio-pharmaceutical industry confirms our predictions. We contribute to research on sourcing and NPD by conceptually building and empirically establishing relevance of the sourcing diversity at the portfolio level of analysis and bringing the question of sourcing strategy to the forefront of NPD portfolio management concerns.

Rural Livelihood Activities

Rural households are found to depend on diverse portfolio of activities and income sources. This study sought to explore the diverse livelihood activities of rural households in Awra Amba Community. Both qualitative and quantitative methodologies were used to collect data. Content analysis method was used to analyze the data. The results of the study revealed that almost all members (94%) of Awra Amba community are depending on non-farm activities because of the scarcity of land. As a result, they are dominantly weavers (86%) and the rest are traders. The results of the study indicated that weaving is their major source of livelihood and a backbone for their survival.

Adapting to extreme events: small drinking water system manager perspectives on the 2012\u20132016 California Drought

Under a changing climate, droughts are projected to increase in frequency and duration in the Southwestern USA. Between 2012 and 2016, California experienced one of the region’s worst droughts, with record high temperatures and low snowpack, runoff, and precipitation. This study documents small drinking water system managers’ experiences during the 2012–2016 Drought. We contribute to research on water system drought resilience by elevating small drinking water system manager perspectives and expertise. We are especially focused on small systems that are not reliant on imports from state or federal water projects. A mixed-method approach ensures each data collection period informs the next to gather statewide perspectives and experiences of managers.Based on an analysis of drinking water manager reflections, the types of impacts, responses, and barriers differed based on both system size and water source portfolio. Common disadvantages that hinder small drinking water systems’ drought resilience and, similarly, climate adaptation include staff and administrative capacity; the financial burden of promoting water conservation over revenue compounded by onerous reporting and funding support programs; consumer awareness challenges; and challenges to consolidation from both local political differences and physical limitations. Systems that built technical, managerial, or financial capacity prior to the Drought were at an advantage over systems that lacked this capacity. In the long term, we found a dearth of adaptation planning among small water systems. Documentation of experiences from the 2012–2016 Drought can inform future planning for droughts and more broadly highlight needs for climate adaptation.

Salicornia dolichostachya organosolv fractionation: towards establishing a halophyte biorefinery.

Halophytes are a potential source of lignocellulosic material for biorefinery, as they can be grown in areas unsuitable for the cultivation of crops aimed at food production. To enable the viable use of halophytes in biorefineries, the present study investigated how different organosolv process parameters affected the fractionation of green pressed fibers of Salicornia dolichostachya. We produced pretreated solids characterized by up to 51.3% ± 1.7% cellulose, a significant increase from 25.6% ± 1.3% in untreated fibers. A delignification yield of as high as 60.7%, and hemicellulose removal of as high as 86.1% were also achieved in the current study. The obtained cellulose could be completely converted to glucose via enzymatic hydrolysis within 24 h. The lignin fractions obtained were of high purity, with sugar contamination of only 1.22% w/w and ashes below 1% w/w in most samples. Finally, up to 29.1% ± 0.4% hemicellulose was recovered as a separate product, whose proportion of oligomers to total sugars was 69.9% ± 3.0%. To the best of our knowledge, this is the first report in which Salicornia fibers are shown to be a suitable feedstock for organosolv biomass fractionation. These results expand the portfolio of biomass sources for biorefinery applications.

Portfolios of learning in entrepreneurial internationalisation

By adopting a process approach to entrepreneurial internationalisation, we longitudinally study eleven case firms, discussing entrepreneurial learning as a portfolio of different sources of learning underpinning the exploration and exploitation of international opportunities. First, we identify the most recurring combinations of learning sources: (i) customer-centred learning with either learning by doing/trial and error or market-specific learning; (ii) imitative learning with relational learning and/or learning by doing; (iii) searching with networking learning and/or customer-centred learning. Second, we uncover instances of opportunity exploitation “looping back” to novel exploration via customer-centred, imitative, and grafting learning. Empirical results are systematised within a set of Propositions to be tested in future research.

Assessment of High-Electrification UK Scenarios with Varying Levels of Nuclear Power and Associated Post-Fault Behaviour

Renewable integration into the electricity system of Great Britain (GB) is causing considerable demand for additional flexibility from plants. In particular, a considerable share of this flexibility may be dispatched to secure post-fault transient frequency dynamics. Pursuant to the unprecedented changes to the traditional portfolio of generation sources, this work presents a detailed analysis of the potential system-level value of unlocking flexibility from nuclear electricity production. A rigorous enhanced mixed integer linear programming (MILP) unit commitment formulation is adopted to simulate several generation-demand scenarios where different layers of flexibility are associated to the operation of nuclear power plants. Moreover, the proposed optimisation model is able to assess the benefit of the large contribution to the system inertial response provided by nuclear power plants. This is made possible by considering a set of linearised inertia-dependent and multi-speed constraints on post fault frequency dynamics. Several case studies are introduced considering 2050 GB low-carbon scenarios. The value of operating the nuclear fleet under more flexible paradigms is assessed, including environmental considerations quantified in terms of system-level CO2 emissions’ reduction.

Intensity of Poverty and Work Diversification: A Study of Female Domestic Workers’ Household

It is now a recognized fact that the earning from a single source does not provide a sufficient means of survival for a majority of poor households in developing countries. Accordingly, most of the poor households depend on a diverse portfolio of activities and income sources. This study is based on a primary survey of 334 female domestic workers in the district of South 24 Parganas, West Bengal, India from January to June 2016. The results of intensity of poverty show that 49% of these households are multi-dimensionally poor with 36.4% intensity of poverty. The severity and acuteness of deprivation is addressed by diversification into non-agricultural employment. The wage of the female domestic worker is not only an important determinant of livelihood strategy it is also a motivating factor for diversification. Large sections of the male workforce diversify into various non-farm activities such as manufacturing and construction in the secondary sector or hotel and restaurant, transport and so on in the services sector. Our findings reveal that diversification into non-farm informal sector is a vital option for livelihood sustenance irrespective of landless or land poor households. JEL Codes: J160, J460, J310, R23

Multi-input, Multi-output Hybrid Energy Systems

Summary Jurisdictions and industries are setting ambitious goals to decarbonize energy systems. Low-cost wind, solar, and natural gas and the resultant dynamic electric grid require energy technologies to adapt in order to meet key attributes for modern energy systems: resilience, reliability, security, affordability, flexibility, and sustainability. When considering energy sources independently and competitively, value-added synergies among energy technologies may be overlooked for meeting demanding, multidimensional requirements. This paper presents novel concepts for tightly coupled hybrid energy systems that leverage capabilities of diverse energy generators, including renewable, nuclear, and fossil with carbon capture, to provide power, heat, mobility, and other energy services. The paper also presents a framework for engineering-based modeling and analysis for complex optimization of energy generation, transmission, services, processes and products, and market interactions. New modeling capabilities are needed to adequately represent multi-input, multi-output tightly coupled hybrid energy systems that utilize multiple feedstocks to create multiple products and services in novel and synergistic ways through increased coordination of energy systems and tightly coupled hybrid system configurations.

Capital Structure, Financial Performance, and Sustainability of Micro-Finance Institutions (MFIs) in Bangladesh

Capital structure plays an important role in organizational performance. Sources of funds for micro-finance institutions (MFIs) and their performance and financial sustainability become an important topic for the MFIs and poverty alleviation initiatives to achieve sustainable development goals of the UN. We explored the following question: Does the financial structure in terms of financial leverage affect the financial performance: Financial sustainability, depth, and breadth of outreach of MFIs? Our research focuses on studying the relationship between capital structure and financial performance of micro-finance institutions as well as achieving the objectives of this program by reaching out to the deserving clients without collaterals. A dataset of 187 MFIs is used to establish the relationship between the capital structure and performance of MFIs. Panel data regression analysis has been used for this study using the Random effect and Fixed effect models. Return on Asset (ROA), and Net Income to Expenditure (NIER) have been used as measures of financial performance. The findings indicate that Equity to Asset Ratio (EAR), Debt to Loan Ratio (DTL), Risk, and Size are the factors that influence NIER. Furthermore, EAR, and DTL have a positive effect on ROA, and Risk has a negative effect. The findings of this study will enable MFIs to configure their capital structure by creating a portfolio of sources of their capital from market-based sources of funds that can maximize their financial performance and reach out to poor clients without collaterals.

Fiscal Resilience Building

Does the reliance on diversified tax structure enhance resilience to fiscal risks? This paper gives an answer to this question by proposing a new cross-country tax revenue diversification index (RDI). The RDI builds on the Theil index, and unlike the few existing tax diversification indices, which are constructed only at the state level for the US, is computed at the national level, covering a broad panel of 127 countries over the period 2000-15. We find suggestive evidence that tax revenue diversification reduces tax revenue volatility, thus bringing to the data long-held views about the prominence of tax revenue diversification for fiscal resilience strengthening. While exploring the drivers of the RDI, we find that tax revenue diversification is not just a reflection of economic diversification, but also an outcome of macroeconomic, political and institutional factors. Interestingly, a non-monotone relationship is also at play between the RDI and economic development, with countries’ portfolio of tax sources getting more diversified as their economy develops, until a tipping point, where richer countries start finding it harder to diversify further their tax revenue sources.

Optimizing sustainable and renewable energy portfolios using a fuzzy interval goal programming approach

Determining the most sustainable renewable energy (RE) source portfolio that meets decision-maker preferences is a complicated and uncertain multi-criteria decision-making (MCDM) problem. The RE selection process involves meeting decision-makers’ (DMs) preferences wherein several conflicting criteria are present, such as environmental, societal, and economic. Fuzzy goal programming (FGP) is one of the most well-known techniques for dealing with uncertainty existing in MCDM problems. However, conventional FGP techniques suppose only one single coefficient (or parameter) for each decision variable. This paper proposes a novel multi-objective decision-making model called fuzzy interval goal programming (FIGP) to release the restrictions of FGP with single-coefficient modeling. The proposed model can formulate an interval coefficient for each decision variable. To formulate such a model, this study adopts the concept of multi-choice aspiration levels (MCALs) from the revised multi-choice goal programming (RMCGP) technique. Specifically, the integrated model considers various types of fuzzy goals in real-world problems and offers DMs more flexibility to express and formulate their preferences in terms of fuzzy interval goals. The proposed method is illustrated by selecting the optimal RE portfolio for electricity generation in Italy. The relevant renewables are biomass, solar photovoltaic (PV), tidal currents, and wind energy. An empirical analysis shows that the proposed methodology is capable of assisting the DMs in ascertaining the optimal portfolio of RE under a high level of uncertainty and in imprecise environments.

Fiscal Resilience Building: Insights from a New Tax Revenue Diversification Index

Does the reliance on diversified tax structure enhance resilience to fiscal risks? This paper gives an answer to this question by proposing a new cross-country tax revenue diversification index (RDI). The RDI builds on the Theil index, and unlike the few existing tax diversification indices, which are constructed only at the state level for the US, is computed at the national level, covering a broad panel of 127 countries over the period 2000-15. We find suggestive evidence that tax revenue diversification reduces tax revenue volatility, thus bringing to the data long-held views about the prominence of tax revenue diversification for fiscal resilience strengthening. While exploring the drivers of the RDI, we find that tax revenue diversification is not just a reflection of economic diversification, but also an outcome of macroeconomic, political and institutional factors. Interestingly, a non-monotone relationship is also at play between the RDI and economic development, with countries' portfolio of tax sources getting more diversified as their economy develops, until a tipping point, where richer countries start finding it harder to diversify further their tax revenue sources.

Factors Affecting Consumption of Water from a Newly Introduced Safe Drinking Water System: The Case of Managed Aquifer Recharge (MAR) Systems in Bangladesh

Rather than committing exclusively to one drinking water option, households in Bangladesh often use a portfolio of sources that, in varying ways, to varying extents satisfy one or more out of several preferences they hold with regard to their drinking water. What happens if a new option is added to that mix? In communities of Bangladesh’ Southwestern coastal region where a new option (managed aquifer recharge, or MAR) was recently introduced, we observe variation in the extent to which this source contributes to satisfying households’ drinking water needs. Using multiple linear regression (n = 636 households), we found that perceived risk, costs, taste, self-efficacy, and form and intensity of competition with alternative drinking water options matter significantly.

Energy Scenario Analysis for the Nordic Transport Sector: A Critical Review

Experiencing the highest growth in emissions since 1990 and relying mainly on oil, transport is considered the most complicated sector to decarbonize. Lately, the Nordic countries have shown remarkable success in reducing greenhouse gas (GHG) emissions, especially in the power and heat sector. However, when it comes to transportation, the greatest source of Nordic GHG emissions, stronger measures are needed. Relying on a rich and diversified portfolio of renewable sources and expertise, the Nordic countries could benefit from a common mitigation strategy by encompassing a larger variety of solutions and potential synergies. This article reviews studies addressing integrated energy and transport scenario analysis for the Nordic region as a whole. The studies targeted are those applying energy system models, given their extensive adoption in supporting scenario analysis. Most notable of these studies is the “Nordic Energy Technology Perspectives 2016” to which a special focus is dedicated. The article reviews the methodological choices and the research content of the selected literature. Challenges/limitations are identified in light of recent transport research, and categorized as: “transport behavior”, “breakthrough technologies”, “domestic energy resources” and “geographical aggregation and system boundaries”. Lastly, a list of suggestions to tackle the identified gaps is provided based on the existing literature.

Network constrained economic dispatch of integrated heat and electricity systems through mixed integer conic programming

This paper proposes an economic dispatch method for an integrated heat and electricity system with respect to network constraints. Network constraints are usually nonlinear and can cause severe difficulties for optimization solvers. Particularly, in a heating network, the mass flow mixing at each node and the pressure and temperature drop along each pipe involve both hydraulic and thermal processes, which can cause high nonlinearity that has not been properly modeled. This paper will firstly model the power and heat network constraints by using a nonlinear model, which is accurate but hard to solve. Then, simplification and convexification will be employed to reform the nonlinear constraints to linear and conic ones. Consequently, the entire economic dispatch problem will be modeled as a mixed integer conic programming problem. Because the proposed model allows for the changes of the mass flow rate and direction, an optimal mass flow profile can be achieved along with the solution of the economic dispatch. Case studies on an integrated district heating and power system with a portfolio of power and heat sources show that the proposed economic dispatch model can handle the complexity of the network constraints and make optimal dispatch plans for multi-energy systems.