Stabilization Methods in the Submerged Arc Discharge Synthesis of Carbon Nanostructures

Many papers, in which the submerged arc discharge (SAD) method in nanoparticle synthesis was used, reported similar operating parameters, but different electrode erosion rate values, different yields and purities of the obtained nanostructures, and a different sort of contaminants present in the synthesis. Analyzing these articles, we found insufficient attention to ensure the arc power stability, which is a key factor guaranteeing the product homogeneity and quality. This paper presents an analysis of different control strategies, remarks their advantages and drawbacks, and proposes the most appropriate technique to be used in SAD. The most appropriate technique is proposed from the SAD stabilization method analysis.

Research on the Evaluation of Customer requirement Importance of Smart Products Based on Online Comments and Improved Quantitative Kano Model

With the development and popularization of smart products, the technological differences of products are decreasing, and the phenomenon of product homogeneity is becoming more and more obvious. It is necessary for the smart product manufacturing firms have the capability to analyze customer requirement deeply and adapt to the dynamically changing market quickly. Therefore, the traditional technology-oriented product development model is no longer suitable for manufacturers to obtain a competitive advantage. Based on this, this paper proposed a method to evaluate the importance of customer demands based on online comments and quantitative Kano model. First, the Python crawler tool is used to obtain online customer reviews of relevant products and the word segmentation processing is performed to obtain the product features and frequency that customers are mainly concerned about, and then the initial importance of demand can be calculated. Furthermore, use the quantitative Kano model to determine the customer satisfaction and revise the initial importance of the requirements to obtain a more reasonable ranking of the importance of user needs. Finally, a case study is carried out with the smart bracelet as an example to verify the effectiveness and feasibility of the model proposed in this paper.

Marginal Utility and Cournot Stability Under Market Entry

This paper introduces into the discussion of the stability of quantity-oligopoly equilibrium, the role that the slope of the marginal utility curve and of market entry in shaping the equilibrium and its stability. It does so by considering inverse multivariate linear demand functions and the notion of stability related to multivariate mean value theorem. The equilibrium cluster of Cournot sellers is determined by the stability dictated by this theorem and the rate of decline of the marginal utility of the product under consideration. Strategic complementarity is found to be the case under product heterogeneity, while the strategic substitutability associated with product homogeneity, induces a modification of Cournot limit theorem.

Influence of Plasma Heating on the Metallurgical Effects of a Continuous Casting Tundish

Steel products have experienced long-standing problems such as unstable product quality and low product homogeneity. In the continuous casting process, realizing constant-temperature pouring is an effective way to improve product homogeneity. Plasma heating can compensate for the temperature drop during casting with a tundish and maintain a stable degree of superheating of the molten steel in the tundish. Plasma heating has a certain impact on the cleanliness of the molten steel and on the tundish covering flux in the tundish while compensating for the temperature drop. This paper uses SEM-EDS, XRD and FactSage to analyze the cleanliness of molten steel and the characteristics of the tundish covering flux before and after plasma heating. The results show that the number density of inclusions in the tundish is significantly lower after heating, improving the floating removal of small-sized inclusions; after heating, the surface morphology of the tundish covering flux sample appears transparent and glassy, with uniform morphology. XRD results show that the tundish covering flux after plasma heating exhibits no crystal precipitation and is amorphous and that there is a certain regularity before and after heating; there are no obvious changes in the composition of the tundish covering flux in the liquid phase area.

Influence of Plasma Heating on the Metallurgical Effects of a Continuous Casting Tundish

Steel products have experienced long-standing problems such as unstable product quality and low product homogeneity. In the continuous casting process, realizing constant temperature pouring is an effective way to improve product homogeneity. Plasma heating can compensate for the temperature drop during casting with a tundish and maintain a stable degree of superheating of the molten steel in the tundish. Plasma heating has a certain impact on the cleanliness of the molten steel and on the tundish covering flux in the tundish while compensating for the temperature drop. This paper uses SEM-EDS, XRD and FactSage to analyze the cleanliness of the molten steel and the characteristics of the tundish covering flux before and after heating. The results show that the number density of inclusions in the tundish is significantly lower after heating, improving the floating removal rate of small-sized inclusions; after heating, the surface morphology of the tundish covering flux sample appears transparent and glassy, with uniform morphology; XRD results show that the tundish covering flux after plasma heating exhibits no crystal precipitation and is amorphous and that there is a certain regularity before and after heating; there are no obvious changes in the composition of the tundish covering flux in the liquid phase area.

Numerical simulation analysis of the influence of ultra-fine glass fiber production process on product homogeneity

Glass fiber felt is produced by flame blowing process, in which primary glass filament splits into glass fiber through the gas jet into the diffusion duct. In the diffusion duct, the velocity difference at axial direction creates a fiber recirculating zone at some position downstream in the duct while affecting the homogeneity of the product. In order to understand the impact of diffusion duct design to the felt forming, numerical simulations with experiment-based boundary conditions were performed to investigate the movement of fiber suspension flow. In the numerical analysis, the fiber slender-body theory is introduced. A visualization method is developed to characterize the uniformity of glass fiber, through charge coupled device camera imaging demonstrating the intensity of glass fiber in the surface of the product. The proposed methodology enabled new design of the diffusion duct, which eliminated the recirculating zone in the duct, resulting in more uniform products.

Analysis of the Valuation Activity on Vegetables and Fruits Chains for their Improvement

The cultivation of vegetables and fruit trees was the main activity of the Romanian farms, a country badly affected both by the process of nationalization / collectivization during the communist period and by the defective retrocession of the post-communist period. But since 2007, investments in agriculture, including those in the fruit and vegetables sector, have played an essential role, both by setting up new agricultural holdings and by upgrading the existing ones. During the programming period 2007-2013 and 2014-2020, farmers could access measures that can be plunged into the fruit and vegetable sector. Starting from the main advantages of the fruit and vegetables sector, such as the large assortment of fruit and vegetable species and varieties, the large number of farms, the pedo-climatic conditions favorable to the cultivation of a significant number of varieties, the growing of the areas cultivated with vegetables in protected areas Modernization of the processing units, improving the fruit and vegetable harvesting activity play a particularly important role in the revitalization of this sector. The market for vegetables and fruits is influenced by a number of factors such as: the demand and supply atomicity, product homogeneity, the seasonality of vegetable and fruit products, the high degree of perishability, the demand for vegetables and fruits has a continuous character, the production of vegetables and fruits has different destinations. Modern analysis of the global value chain focuses on actors’ relationships as a way to reduce uncertainty, improve access to key resources and increase chain efficiency. For the proper functioning of the vegetable and fruit chain, the producer groups and producer organizations are extremely important.

Competitive Behavior of Developers' Development Scale in the Assembled Construction Market: An Analysis Based on Game Theory

The paper constructs the oligopoly models of assembled building developers based on Cournot model and Stackelberg model of development scale competition. Based on the comparison of the profit of the regional assembled building market, which is obvious in product homogeneity and multi oligopoly, a game analysis is carried out for the development pattern of assembled building developers. On the basis of the above models, we get the equilibrium solution of developers' Cournot competition and the sub game refining Nash equilibrium solution of the developers' Stackelberg competition respectively. Based on the different N values, we compare the development scale, the development income and the market price of the two competitive modes. Combining with the above game equilibrium, this paper makes a concrete analysis of the actual situation of the competition of assembled building developers in China.

Compatible effect or competitive effect: An investigation of attraction spatial interdependency

This study empirically examines the spatial interdependency of attractions, using a unique database of 75 important attractions in Guangdong (GD) province, China and spatial econometric models. According to the estimation results, compatible effects apply to the samples in GD overall and in eastern GD, while competitive effects apply to the samples in northern GD. To analyze further, this study finds attraction theme matters to the nature of spatial interdependency. There are competitive effects among natural attraction (NA) and man-made attraction (MA) and insignificant compatible effects among cultural attractions. The competitive effects among NAs have a root in the competition for tourists’ time budget, and competitive effects among MAs are related to product homogeneity, resulting from the ubiquitous product imitation in MAs in China. This study concludes that to distinctly diversify attraction theme is a critical way to generate a positive spatial interdependency among attractions within a certain geographic area.