ALBERT

Description: Sustainability, Vol. 9, Pages 1928: A Co-Word Analysis of Organizational Constraints for Maintaining Sustainability Sustainability doi: 10.3390/su9101928 Authors: Daoyan Guo Hong Chen Ruyin Long Hui Lu Qianyi Long A good understanding of organizational constraints is vital to facilitate organizational development as the sustainable development of organizations can be constrained by the organization itself. In this study, bibliometric methods were adopted to investigate the research status and trends of organizational constraints. The findings showed that there were 1138 articles and reviews, and 52 high-frequency keywords related to organizational constraints during the period 1980–2016. The research cores were “constraints”, “learning”, “institution”, and “behavior” in the co-occurrence network, and “constraints” played the most significant role. The 52 high-frequency keywords were classified into six clusters: “change and decision-making”, “supply chain and sustainability”, “human system and performance”, “culture and relations”, “entrepreneur and resource”, and “learning and innovation”. Furthermore, the indicators of organizational development (e.g., innovation, supply chain, decision-making, performance, sustainability, and employee behavior) were found to be significantly related to the organizational constraints. Based on these findings, future trends were proposed to maintain the sustainability of organizations. This study investigated the state of the art in terms of organizational constraints and provided valuable references for maintaining the sustainable development of organizations.

Description: Uniaxial compressive strength (UCS) and peak strain (PS) are essential indices for studying the mechanical properties of coal and rock masses, and they are closely related to mechanical parameters such as the elastic modulus (E), Poisson’s ratio (υ), cohesion (C) and internal friction angle (Φ) of coal and rock masses. This study took the No. 2-1 coal seam of Zhaogu No. 2 Mine, in Henan Province, China, as the research object. An RMT-150B servo testing machine was used to test all mechanical parameters, including the E, υ, C and Φ of coal and rock masses. Based on the principle of orthogonal testing, Three Dimensions Fast Lagrangian Analysis of Continua (FLAC3D) was used to select E, υ, C, Φ, tensile strength (Rm) and dilation angle (Ψ) as initial participation factors. Using these six parameters and a five-level combination scheme (L25 (56)), the influence of coal mechanical parameters on UCS and PS was investigated, using the software SPSS for stepwise regression analysis, and a uniaxial pressure-resistant regression prediction equation was established. The research showed that, under uniaxial compression conditions, the main parameters controlling UCS of coal masses are C and Φ; conversely, the main parameters controlling PS are E and C. UCS and PS exhibit significant linear relationships with these main controlling parameters. Here, a stepwise regression prediction equation was established through reliability verification analysis using the main controlling parameters. This prediction method produces very small errors and a good degree of fit, thus allowing the rapid prediction of UCS. The precision of the stepwise regression model depends on the number of test samples, which can be increased in the later stages of a design project to further improve the precision of the projection model.

Description: Power transformers are one of the most important devices in electrical networks. The safety operation of the transformers directly affects the reliability of the power system. To diagnose the internal deformation of the transformer as soon as possible is of great significance. As a new technique, sweep frequency impedance (SFI) method has been used to detect the short-circuit fault of the transformer winding. However, the SFI method is still in the early stage and more experimental tests are needed to further demonstrate its accuracy in the detection of other types of winding faults. Therefore, in this paper, the SFI method is investigated to diagnose an open-circuit fault of an onsite transformer. By deeply analyzing the SFI curves and SFI values at power frequency obtained by the SFI test, the open-circuit fault of this transformer winding is determined. Meanwhile, the accuracy of the diagnostic results based on the SFI method is validated by introducing the results of the short-circuit impedance (SCI) and winding resistance measurements. The application of the SFI method on the detection of the open-circuit fault within the transformer winding not only enrich the SFI method research but also provide valuable practical guidance significance for the fault detection.

Description: The paper proposes a new hybrid method based on cuckoo search (CSA) and sunflower optimization (SFO) approach (called HCSA-SFO) for improving the performance of solutions in the optimization power system operation problem. In the power system, the optimal power flow (OPF) problem is one of the important factors which usually minimizes total cost and total active power losses while satisfying all constraints of the output power of generators, the voltage at buses, power flow on branches, the capacity of capacitor banks and steps of transformer taps. HCSA-SFO utilizes the mutation and selection mechanism in the SFO algorithm to replace the Lévy flights function in CSA. Hence, this makes HCSA-SFO avoid the fixed step size in the CSA from that can reduce run time and improve the quality of solution for the HCSA-SFO algorithm in the OPF problem. The proposed hybrid technique is simulated on the 30-buses and 118-buses systems. The obtained simulation results from the suggested technique are compared to many other approaches. The result comparisons in different cases showed that the suggested HCSA-SFO can achieve a better result than many other optimization approaches. Therefore, the suggested HCSA-SFO is also an effective approach for dealing with the OPF problem.

Description: Coal blending is an effective way to organize and control coal ash fusibility to meet different requirements of Coal-fired power plants. This study investigates three different eutectic processes and explains the mechanism of how coal blending affects ash fusibility. The blended ashes were prepared by hand-mixing two raw coal ashes at five blending ratios, G:D = 10:90 (G10D90), G:D= 20:80 (G20D80), G:D = 30:70 (G30D70), G:D = 40:60 (G40D60), and G:D = 50:50 (G50D50). The samples were heated at 900 °C, 1000 °C, 1100 °C, 1200 °C, and 1300 °C in reducing atmosphere. XRD and SEM/EDX were used to identify mineral transformations and eutectic processes. The eutectic processes were finally simulated with FactSage. Results show that the fusion temperatures of the blended ashes initially decrease and then increase with the blending ratio, a trend that is typical of eutectic melting. Eutectic phenomena are observed in D100, G10D90, and G30D70 in different degrees, which do not appear in G100 and G50D50 for the lack of eutectic reactants. The main eutectic reactants are gehlenite, magnetite, merwinite, and diopside. The FactSage simulation results show that the content discrepancy of merwinite and diopside in the ashes causes the inconsistent eutectic temperatures and eutectic degrees, in turn decrease the fusion temperature of the blended ash and then increase them with the blending ratio.

Description: The electric vehicle charging infrastructure is in the initial development period in China, where there is an imbalanced supply and demand structure, an increasingly mature institutional environment, and an imperfect support system. The infrastructure is important for supplying energy to electric vehicles, and it needs to be provided in a reasonable manner with a moderately advanced layout. Due to large-scale investment, unclear financing rights and responsibilities, a single participant, interlinked risks, and other factors, “absence” and “dislocation” of the charging infrastructure coexist. The public–private partnership (PPP) model is an effective supply path for the infrastructure. Thus, introducing the PPP model into the charging infrastructure can leverage social capital, eases the burden on local finance, enhances the level of project management and profitability, and reduces construction and operation risks. For the participant level of PPP projects in the charging infrastructure, the present study elucidates the support mechanisms required by the government, social capital, and intermediaries in order to construct an effective charging infrastructure in China.

Description: An experimental study was performed to investigate the effect of subcritical carbon dioxide (CO2) adsorption on mechanical properties of shales with different coring directions. Uniaxial compressive strength (UCS) tests were conducted on shale samples with different CO2 adsorption time at a pressure of 7 MPa and a temperature of 40 °C. The crack propagation and the failure mechanism of shale samples were recorded by using acoustic emission (AE) sensors together with ARAMIS technology. According to the results, samples with parallel and normal bedding angles present reductions of 26.7% and 3.0% in UCS, 30.7% and 36.7% in Young’s modulus after 10 days’ adsorption of CO2, and 30.3% and 18.4% in UCS, 13.8% and 22.6% in Young’s modulus after 20 days’ adsorption of CO2. Samples with a normal bedding angle presented higher brittleness index than that with a parallel bedding angle. The strain distributions show that longer CO2 adsorption will cause higher axial strains and lateral strains. The AE results show that samples with a parallel angle have higher AE energy release than the samples with a normal angle. Finally, samples with longer CO2 adsorption times present higher cumulative AE energy release.

Description: A burgeoning population, pressing development needs and increasing household consumption are rapidly accelerating water use in direct and indirect ways. Increasingly, regions around the world face growing pressure on sustainable use of their water resources especially in arid and semi-arid regions, such as Northern China. The aim of this research is to obtain an overview of the cumulative water requirement for direct (domestic) water use and indirect water use for the basic food consumption of the households in the Inner Mongolia Autonomous Region (IMAR), in order to reduce the pressure on grassland of Western China by encouraging sustainable water consumption. For indirect water use, we use VWC (virtual water content) analysis theory to analyze the total consumption package of 15 basic food types that were identified and quantified based on the household survey in 2011. In this survey, domestic water consumption data and food consumption data were collected from 209 representative households with spatial variation across three sub-regions (including meadow steppe in Hulun Buir, typical steppe in Xilin Gol, and semi-desert steppe in Ordos) and temporal variation from 1995 to 2010. The results show that the total amounts of food consumption per capita in three sub-regions all show an increasing trend, especially in Hulun Buir and Ordos. Compared to the direct water consumption, the indirect water consumption behind food production made up a major portion of total water consumption, which is affected (1) geographic locations (grassland types); (2) economic development levels and (3) grassland use policy measures. From 1995 to 2010, indirect water consumption displays a decreasing trend in Xilin Gol and Ordos due to the decrease of meat consumption and increase of fruit and vegetable consumption. When considering the amount of land per household, the grassland in Ordos still faces the great threat of high water consumption pressure. Such water consumption may affect water conservation services and productivity of grassland. Therefore, changing diet behavior and reducing the population can be considered options for sustainable use of water.

Description: In order to clarify the potential of internal purification methods on medium speed diesel engines to meet the IMO Tier III nitrogen oxide (NOx) emission regulations, combined 1-D engine working cycle simulation and 3-D CFD simulation were conducted to predict the performance and emissions of the engine under different valve close timings, geometric compression ratios, injection timings, and Exhaust Gas Recirculation (EGR) rates. The numerical results show that, as the inlet valve close timing is advanced, NOx is reduced by as much as 27%, but the peak of premixed combustion heat release rate is increased; this can weaken the ability to reduce NOx with the Miller cycle. Moreover, the peak of premixed combustion heat release rate is reduced when the geometric compression ratio is increased to 15.4, and linking with injection timing by delaying 6°CA can further reduce NOx by 55.3% from the baseline. Finally, over 80% NOx reduction can be achieved when the above schemes are combined with over 15% EGR. The NOx and soot can be reduced simultaneously by using moderate Miller cycle combination with moderate EGR, and the results show a large reduction of NOx and moderate reduction of soot. This can be a feasible technical solution to meet Tier III regulations.