14 research outputs found
Vocational education and training for operators of modern enterprises
The idea of how to run an effective and efficient vocational education and training system (EEVETS) with enterprises is given in this paper. It includes curriculum, teaching method, teaching support, quality control and management, etc. The keys to form EEVETS are demand analysis, motivation mechanism, teachers and tutors, quality control and service support. The training system for modern power station operators is briefly given as an example
Recovery of Acid and Base from Sodium Sulfate Containing Lithium Carbonate Using Bipolar Membrane Electrodialysis
Lithium carbonate is an important chemical raw material that is widely used in many contexts. The preparation of lithium carbonate by acid roasting is limited due to the large amounts of low-value sodium sulfate waste salts that result. In this research, bipolar membrane electrodialysis (BMED) technology was developed to treat waste sodium sulfate containing lithium carbonate for conversion of low-value sodium sulfate into high-value sulfuric acid and sodium hydroxide. Both can be used as raw materials in upstream processes. In order to verify the feasibility of the method, the effects of the feed salt concentration, current density, flow rate, and volume ratio on the desalination performance were determined. The conversion rate of sodium sulfate was close to 100%. The energy consumption obtained under the best experimental conditions was 1.4 kWh·kg−1. The purity of the obtained sulfuric acid and sodium hydroxide products reached 98.32% and 98.23%, respectively. Calculated under the best process conditions, the total process cost of BMED was estimated to be USD 0.705 kg−1 Na2SO4, which is considered low and provides an indication of the potential economic and environmental benefits of using applying this technology
The Architecture Optimization and Energy Management Technology of Aircraft Power Systems: A Review and Future Trends
With the development of More/All-Electric Aircraft, especially the progress of hybrid electrical propulsion or electrical propulsion aircraft, the problem of optimizing the energy system design and operation of the aircraft must be solved regarding the increasing electrical power demand-limited thermal sink capability. The paper overviews the state of the art in architecture optimization and an energy management system for the aircraft power system. The basic design method for power system architecture optimization in aircraft is reviewed from the multi-energy form in this paper. Renewable energy, such as the photo-voltaic battery and the fuel cell, is integrated into the electrical power system onboard which can also make the problem of optimal energy distribution in the aircraft complex because of the uncertainty and power response speed. The basic idea and research progress for the optimization, evaluation technology, and dynamic management control methods of the aircraft power system are analyzed and presented in this paper. The trend in optimization methods of engineering design for the energy system architecture in aircraft was summarized and derived from the multiple objective optimizations within the constraint conditions, such as weight, reliability, safety, efficiency, and characteristics of renewable energy. The cost function, based on the energy efficiency and power quality, was commented on and discussed according to different power flow relationships in the aircraft. The dynamic control strategies of different microgrid architectures in aircraft are compared with other methods in the review paper. Some integrated energy management optimization strategies or methods for electrical propulsion aircraft and more electric aircraft were reviewed. The mathematical consideration and expression of the energy optimization technologies of aircraft were analyzed and compared with some features and solution methods. The thermal and electric energy coupling relationship research field is discussed with the power quality and stability of the aircraft power system with some reference papers. Finally, the future energy interaction optimization problem between the airport microgrid and electric propulsion aircraft power system was also discussed and predicted in this review paper. Based on the state of the art technology development for EMS and architecture optimization, this paper intends to present the industry’s common sense and future trends on aircraft power system electrification and proposes an EMS+TMS+PHM to follow in the electrified aircraft propulsion system architecture selectio
The effect of urban basic medical insurance on health service utilisation in Shaanxi Province, China: a comparison of two schemes.
BACKGROUND: Urban population in China is mainly covered by two medical insurance schemes: the Urban Employee Basic Medical Insurance (UEBMI) for urban employees in formal sector and the Urban Resident Basic Medical Insurance (URBMI) for the left urban residents, mainly the unemployed, the elderly and children. This paper studies the effects of UEBMI and URBMI on health services utilisation in Shaanxi Province, Western China. METHODS: Cross-sectional data from the 4th National Health Services Survey - Shaanxi Province was studied. The propensity score matching and the coarsened exact matching methods have been used to estimate the average medical insurance effect on the insured. RESULTS: Compared to the uninsured, robust results suggest that UEBMI had significantly increased the outpatient health services utilisation in the last two weeks (p<0.10), whilst the significant effect on hospitalisation was evident in the CEM method (p<0.10). The effect of URBMI was limited in that although being insured was associated with higher health services utilisation, compared with the uninsured, none of the improvement was statistically significant (p>0.10). It was also found that compared with the uninsured, basic medical insurance enrollees were more likely to purchase inpatient treatments in lower levels of hospitals, consistent with the incentive of the benefit package design. CONCLUSION: Basic Medical insurance schemes have shown a positive but limited effect on increasing health services utilisation in Shaanxi Province. The benefit package design of higher reimbursement rates for lower level hospitals has induced the insured to use medical services in lower level hospitals for inpatient services
Urban Basic Medical Insurance Schemes in Shaanxi Province, China (Year 2008).
<p>Source: China Labour Statistical Yearbook 2009.</p><p>UEBMI - Urban Employee Basic Medical Insurance; URBMI - Urban Resident Basic Medical Insurance.</p
Logistic regression results for propensity scores.
<p>Note: *p<0.1, **p<0.05, ***p<0.01.</p
Comparison of analysis sample characteristics before and after matching (UEBMI and Uninsured).
<p>Comparison of analysis sample characteristics before and after matching (UEBMI and Uninsured).</p
Effect of UEBMI on health services utilisation by the level of hospitals.
<p>Note: Chi-square test was used to testify the significant difference.</p
The L1 measure of imbalance before and after Coarsened Exact Matching.
<p>The L1 measure of imbalance before and after Coarsened Exact Matching.</p
Comparison of analysis sample characteristics before and after matching (URBMI and Uninsured).
<p>Comparison of analysis sample characteristics before and after matching (URBMI and Uninsured).</p