Research summary: In this study, we revisit the relationship between corporate social performance (CSP) and corporate financial performance (CFP) by conducting a replication of Waddock and Graves ...(1997). Using 1990 KLD ratings as the CSP measure, the original study reports a positive bidirectional relationship between CSP and CFP. However, our replication analyses with a larger sample over a longer time period indicate that the findings of the original study may not be generalizable to different samples. We argue that our replication casts doubt on the original study and can serve as a starting point to reconsider the CSP-CFP relationship. Based on the findings of our replication, we discuss the differences between the replication results and the original findings, and then suggest several approaches to revise and extend the original study. Managerial summary: Advocates of corporate social performance (CSP) have long argued that "doing good leads to doing well." However, the evidence to support this argument is not strongly convincing, and managers hence doubt whether better CSP leads to improved corporate financial performance (CFP). In this article, we directly examine the relationship between CSP and CFP. Our article reports that CSP may not have a positive influence on CFP. Instead, our article shows the complexity of the relationship between CSP and CFP. Therefore, we cannot simply argue that doing good will necessarily lead to doing well.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Monitoring environmental evolutions, one of the most crucial axes on which sustainable development is based, requires the knowledge of information on the observed geographical scenes. Due to the ...continuous technological developments in the remote sensing field, the data sources increase exponentially over time, and the information contained in satellite images becomes increasingly rich. These characteristics make the extraction, processing and resolution of such data a complicated task that varies according to the situation. It is, therefore, necessary to develop tools adapted to satellite images interpretation and analysis problems. In this context, the constraint satisfaction problem (CSP) seems to be one of the methods to solve these problems. Despite some challenges, the CSP approach has performed well and proven its value in various fields. The effectiveness of CSP is based on two key points: first, the definition of constraints, and second, the choice of resolution methods. Therefore, a synthesis document covering CSP resolution methods, both static and dynamic, becomes relevant and necessary.
This paper represents the first comprehensive review of CSP. We begin by listing CSP methods, detailing their principles, and presenting the corresponding algorithms. We then illustrate the execution process of CSP methods using examples applied in the remote sensing domain for each one. Following this, we present a complete comparative study arranged according to key characteristics, which is intended to guide researchers to help them select the most appropriate resolution method for any given context. Finally, we present a set of challenges and future directions designed to suggest and drive further research in this promising field.
•A comprehensive survey of resolution methods for constraint networks: static and dynamic algorithms•This paper represents the first comprehensive review of CSP resolution methods.•A guide of the most appropriate CSP resolution method for a given context•A set of challenges and future directions designed to suggest and drive future research in the field of CSP.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
An attempt has been made to explore the effect of hybrid reinforcement on mechanical properties and dry sliding wear behavior of vinyl ester (VE) composites. Vinyl ester reinforced with alkali ...treated coir fibers (CF-VE), silanated aramid fibers (AFs) leading to fibridization and inclusion of coconut shell powder (CSP) with various weight proportions has been prepared resulting in hybridization. Effectiveness of treated fibers and CSP on mechanical and wear behavior of VE and their hybrids was evaluated. The density and hardness values of CF-VE composite increased steadily with inclusion of AFs and CSP. The tensile strength increased from 52 MPa at 0 wt.% AFs inclusion to a maximum of 76 MPa at 15 and 5 wt.% of AFs and CSP content. Further, it increased to a maximum of 78 MPa at 5 and 10 wt.% of AFs and CSP in CF-VE composite. The specific wear rate decreased more rapidly with the CSP content. Hence, it is deduced that hybrid VE (15CFs+5AFs) composite with 10 wt.% CSP is more effective against sliding wear. The type, geometry and dispersion of reinforcements contribute to the increased wear resistance. These results are important for the development of new composites incorporated with surface treated reinforcing materials such as CF and CSP, which will have significant application in automotive sliding or bearing components.
•A thorough review on thermal energy storage technologies and their applications.•Levelized cost of electricity is significantly reduced by combining TES and CSP.•In the current survey, TES is used ...in 45.5% of operational CSP plants worldwide.•95.6% of these plants (99.8% of installed capacity) integrate liquid SHS materials.•Environmental potential of TES and CSP plants was quantified through a case study.
The concentrating solar power (CSP) technology is promising especially for countries having an abundance of solar resources in order to secure their energy supply, reduce their carbon footprint and consequently achieve sustainable development goals. Furthermore, the thermal energy storage (TES), when combined with CSP plants, offers the opportunity to make these plants economically competitive and reliable during their operation and could balance supply and demand of energy by reducing the undesirable impacts of the solar energy intermittency. This paper presents a review on TES systems and an update of the latest developments of different technologies of TES that are commercially available or under investigation. Various aspects are discussed including the limits of each technology, different new concepts to enhance the heat transfer efficiency, the principal applications and the environmental issues associated with the integration of TES in solar thermal CSP plants. The results of the current review have revealed that despite the important thermo-physical characteristics of latent heat and thermo-chemical heat storage systems, such as high TES density, they are still at a laboratory level and their development is still far from any proven design and material to be transferred to a commercial scale, especially for high temperature applications. In contrast, the liquid sensible heat storage (SHS) systems are the most mature and the most used in CSP plants. Indeed, according to a census survey that we carried out, based on data compiled by the National Renewable Energy Laboratory (NREL) and Global Energy Observatory (GEO) about CSP projects around the world that are either operational or under development, 45.5% of the operational CSP plants worldwide (i.e. 45.1% of the total installed capacity) are equipped with TES and 95.6% of them (i.e. 99.8% of the total installed capacity) use liquid SHS materials due to their reliability, low cost and easy operation. Economically, the integration of TES systems into large scale CSP plants is a cost-effective way for the widespread deployment of CSP technology, by reducing the levelized cost of electricity (LCOE), especially for solar power tower (SPT) technology over parabolic trough collector (PTC) one, thanks to the high temperature differential occurred in the storage system that reduces the amount of required TES materials. However, owing to its longer commercial operational experience and less technical and financial risks, the PTC is currently the most commonly used technology in CSP plants. Regarding the environmental side, a case study about Moroccan CSP has quantitatively highlighted the environmental potential of integrating TES in CSP plants for electricity production in order to mitigate significantly the greenhouse gases emissions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Assessment of CSP and PV soiling using real-time soiling sensors (TraCS and DustIQ)•One-year performance analysis of a simulated PV and CSP solar plants was performed.•Soiling optical effect for CSP ...mirrors is around 5 to 6 times higher compared to PV.•CSP energy loss due to soiling is 8 times higher compared to PV.•3 weeks cleaning frequency yields highest profitability for PV and CSP solar plants.
Many sites suitable for photovoltaic (PV), concentrated solar power (CSP) or hybrid CSP/PV plants are located in the desert or arid and semi-arid areas, where they can suffer from soiling accumulation on the surfaces of solar collectors. The aim of this research is to assess the impact of soiling on the annual performance of CSP and PV solar power plants from a technical and economic perspective. The yield analysis of 1MWe linear Fresnel CSP and 1MWe PV solar power plant is performed under the semi-arid climate of Morocco. One year of ground-based and quality-checked meteorological data, as well as one year of soiling data collected from two soiling monitoring sensors (a Tracking Cleanliness Sensor (TraCS) and a DustIQ) are considered in the analysis. The optical soiling loss is 5 to 6 times higher in case of CSP compared to PV, with an annual average daily of 1.21 %/day and 0.24 %/day, respectively. The total annual energy loss due to soiling, considering a monthly cleaning frequency, is equivalent to 17.76 % and 1.95 % for CSP and PV, respectively. The energy loss depends not only on the optical efficiency drop due to soiling, but also on the available solar resources at the location. The LCoE increases significantly if the impact of soiling is accounted, especially for CSP technology. The analysis of the different cleaning profiles reveals that the cleaning frequency of 3 weeks gives the highest profitability for both PV and CSP solar plants.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, SAZU, SBCE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Solar thermal technologies for power generation have become cost-effective, efficient, flexible, and play a prominent role in achieving low-carbon energy systems. Concentrated solar power is the main ...solar technology for large-scale power generation and can offer thermal energy storage capacity, delivering power to the grid with high reliability, high capacity factor and low cost. However, their operation is constrained by the maximum temperature allowable for the heat transfer fluids used (up to 565 °C using molten salts). Continuous efforts are in progress to demonstrate the scalability, reliability, functionality, and performance of different concentrated solar thermal components and liquid heat transfer fluids for third-generation concentrated solar power plants. Third-generation concentrated solar power plants are characterized by: (a) operating at temperatures above 700 °C and (b) increasing the capacity, reliability, efficiency and stability of the system network. To date, several authors have evaluated the performance of novel liquid, solid particles and gaseous/supercritical heat transfer fluids, triggering intense development of new receivers, enhanced heat exchangers, storage systems, new materials, and their aging tests, among others. The present study compiles the recent literature referred to the liquid-pathway of third-generation concentrated solar power plants, emphasizing the relevant lines of research and the issues to be resolved in the coming years on high-temperature receivers, heat transfer fluids and storage concepts, as well as suitable high-temperature thermodynamic cycles.
•A liquid-pathway overview of Gen3 CSP plants is presented.•Latest scientific advances concerning liquid-based Gen3 CSP plants are included.•LCOE reductions of up to 10% are reported in the literature.•Research gaps and future prospects are identified.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Although high-performance human resource practices do not directly affect corporate social performance (CSP) strengths, they do positively affect CSP strengths in companies that are highly innovative ...or have high levels of slack. High-performance human resource management (HRM) practices also directly and negatively affect CSP concerns. Drawing on the resource-based view and using secondary data from an objective, third-party database, the authors develop and test hypotheses about how high-performance HRM affects a company’s CSP strengths and concerns. Findings suggest that HRM and innovation are important capabilities because they create and enhance other capabilities.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
•NaCl, KCl, MgCl2, CaCl2, and ZnCl2 are formulated for eutectic salts for HTF.•16 selected eutectic binary and ternary molten salts are provided for candidates.•Surveyed equations and correlations ...for transport properties are provided.•Best equations and correlations for property calculation are recommended.
Considered as promising candidates of composing eutectic chloride molten salts for high temperature heat transfer fluid (HTF) with low corrosivity to nickel-based alloys, NaCl, KCl, MgCl2, CaCl2, and ZnCl2 are formulated into proper binary and ternary mixtures to satisfy the property requirement for HTFs. Experimental and predicted thermophysical properties of 16 selected eutectic binary and ternary molten salts are provided. The molten salts can work in a temperature range from after eutectic melting to at least 800°C with low vapor pressure and acceptable low corrosivity. Surveyed equations and correlations for thermophysical properties of salt mixtures are used to predict heat capacity, density, thermal conductivity, and viscosity. The results are compared to experimental data from the author’s tests as well as reported in literature. Evaluated equations and correlations that can better predict the transport properties of the salts are selected and recommended. Authors expect that more experimental tests will be conducted to provide data for application in CSP industry.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In concentrated solar power (CSP) plants based on parabolic trough collectors (PTC), the sun is tracked at discrete time intervals, with each interval representing a movement of the collector system. ...The act of moving heavy mechanical structures can lead to the development of cracks, bending, and/or displacement of components from their optimal optical positions. This, in turn, diminishes the overall energy capture performance of the entire system. In this context, we introduce two combinatorial optimization problems of great interest to PTC plants. The minimum tracking motion (MTM) problem is aimed at detecting the minimum number of movements needed while maintaining production within a given range. The maximal energy collection (MEC) problem seeks to achieve optimal energy production within a predetermined number of movements. Both problems are solved assuming scenarios where the energy collection function contains any number of local maximums/minimums due to optical errors of the elements in the PTC system. The MTM and MEC problems are solved in O(n) time and O(n2mω∗) time respectively, where n is the number of steps in the energy collection function, m the maximum number of movements of the solar structure, and ω∗ the maximal amplitude angle that the structure can cover. The advantages of the solutions are shown in realistic experiments. While these problems can be solved in polynomial time, we establish the NP-hardness of a slightly modified version of the MEC problem. The proposed algorithms are generic and can be adapted to schedule solar tracking in other CSP systems.
•New optimization problems are defined in the context of solar tracking.•Minimum Tracking Motion and Maximal Energy Collection are solved in polynomial time.•90% of the energy is captured with 75% of the movements of the solar collector.•A variant of the Maximal Energy Collection problem is NP-hard.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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