A Scientometric Review of Grain Storage Technology in the Past 15 Years (2007–2022) Based on Knowledge Graph and Visualization

Food storage helps to ensure the food consumption needs of non-agricultural populations and to respond to major natural disasters or other emergencies, and the application of food storage technology can reduce post-harvest food losses. However, there are still obvious shortcomings in coping with large grain losses. Therefore, quantitative analysis of the research hotspots and evolutionary trends of grain storage technology is important to help the development of grain storage technology. This article uses the Web of Science database from 2007 to 2022 as a data sample with the help of CiteSpace software to analyze the basic situation, research hotspots, and evolutionary trends to draw a series of relevant knowledge maps. Visual analysis revealed that the number of publications had grown rapidly since 2015. First, the Journal of Stored Products Research, Journal of Economic Entomology, and Journal of Agricultural and Food Chemistry, with citation frequencies of 929, 536, and 453, should be focused on in order to keep up with the latest research developments in this field. The United States, China, and Brazil occupy dominant positions in relation to grain storage technology studies in general. Purdue University, Kansas State University, and Agricultural Research Institute ranked the top three in terms of the number and centrality of publications. In terms of research hotspots, the centrality of temperature, insects, carbon dioxide, and quality were 0.16, 0.09, 0.08, and 0.08. It shows that the field of grain storage technology in recent years has focused on grain storage temperature, pest control, and grain storage quality research. From the perspective of the evolution trend, the life cycle of emergent words lasts for several years, after which the strength of emergent words slowly decreases and is replaced by new emergent words. Mortality was the first keyword to appear and remained from 2007 to 2011, indicating that research on fumigants and their toxicity, as well as pest mortality under air fumigation and chemical fumigation conditions, became more popular during this period. In recent years, new terms have emerged that had never been used before, such as “grain quality” (2019–2022) and “stability” (2020–2022). We can find that people pursue food quality more with the improvement of people’s living standards. In this context, future research should seek more efficient, safe, economical, and environmentally friendly methods of grain storage and continuously improve the level of scientific grain storage

Investigation on compression and mildew of mixed and separated maize

This study explores the influence of different segregation configurations on the creep behaviors and mildew of maize. An inexpensive and easy-to-use system was designed, and three configurations of maize kernels distribution, i.e., uniform mixing (Mdm), alternating distribution (Mda), and segregated state distribution (Mds), with wet basis moisture content of 22.9%, were compressed under vertical pressure of 200 kPa through a one-dimensional oedometer. The compression and creep behaviors were investigated using the strain/settlement–time results, and aerobic plate counting (APC) was performed to study the effect of distribution configuration on the mildew effect. A finite-element model was established to simulate the temperature variation caused by physical environmental factors, and the heat production by fungi was quantified using the difference in temperature between simulation and test. The results indicate that the three-element Schiffman model can represent the creep behavior of the maize with different distribution configurations. The average temperature of Mdm, Mda, and Mds were 7.53%, 12.98%, and 14.76% higher than the average room temperature, respectively. The aerobic plate count of Mdm, Mda, and Mds were 1.0 × 105, 2.2 × 105, and 8.8 × 105 cfu g−1 stored for 150 h, respectively. In general, the temperature and APC in segregated maize bulk are higher than uniform grain. The effectiveness of the numerical model was verified, and the heat production by maize bulk fungi was quantified using the test and numerical temperature difference. The average heat was the least in Mdm with 2.8 × 106 J m−3, and Mda and Mds were 1.7 and 2 times more than Mdm. And the heat was related to the segregation configurations and agreed very well with the APC and temperature results

Effect of Vertical Pressure on Temperature Field Distribution of Bulk Paddy Grain Pile

Grain storage pressure is an important factor affecting grain pile temperature, and its influencing mechanism needs to be studied further. The distribution and variation of the temperature field of a bulk grain pile under different vertical pressures and a temperature difference of 25 °C are studied by a model test and numerical simulation. Initially, the temperature change and heat transfer law at different points in the bulk grain pile space are studied under different vertical pressures using a self-made test device. Thereafter, a multi-field coupling software platform COMSOL is used to simulate and study the distribution law of the temperature field in the bulk grain pile under different vertical pressures. The influence mechanism of vertical pressure on the temperature field of the grain pile is discussed based on the micro-airflow velocity field obtained by numerical simulation. The results show that the numerical simulation and experimental results are in good agreement. With the increase in vertical pressure, the heat transfer rate of the grain pile increases gradually, the convective heat transfer in the grain pile is hindered, and the temperature distribution gradually attains uniformity. When the vertical pressure increases from 50 kPa to 200 kPa, the temperature of the grain pile decreases by approximately 0.6–2.7 °C, and the rate of change of the temperature gradient reaches 7.4%. Under different vertical pressures, the proportion of the high-temperature area decreases linearly with the storage duration. The micro-airflow velocity field affects the temperature transfer in the bulk grain pile, resulting in the temperature at the top of the storage structure being higher than that at the bottom. The research methods and conclusions in this study can provide theoretical support and reference for the multi-field coupling research on bulk grain pile storage

Effect of Vertical Pressure on Temperature Field Distribution of Bulk Paddy Grain Pile

Grain storage pressure is an important factor affecting grain pile temperature, and its influencing mechanism needs to be studied further. The distribution and variation of the temperature field of a bulk grain pile under different vertical pressures and a temperature difference of 25 °C are studied by a model test and numerical simulation. Initially, the temperature change and heat transfer law at different points in the bulk grain pile space are studied under different vertical pressures using a self-made test device. Thereafter, a multi-field coupling software platform COMSOL is used to simulate and study the distribution law of the temperature field in the bulk grain pile under different vertical pressures. The influence mechanism of vertical pressure on the temperature field of the grain pile is discussed based on the micro-airflow velocity field obtained by numerical simulation. The results show that the numerical simulation and experimental results are in good agreement. With the increase in vertical pressure, the heat transfer rate of the grain pile increases gradually, the convective heat transfer in the grain pile is hindered, and the temperature distribution gradually attains uniformity. When the vertical pressure increases from 50 kPa to 200 kPa, the temperature of the grain pile decreases by approximately 0.6–2.7 °C, and the rate of change of the temperature gradient reaches 7.4%. Under different vertical pressures, the proportion of the high-temperature area decreases linearly with the storage duration. The micro-airflow velocity field affects the temperature transfer in the bulk grain pile, resulting in the temperature at the top of the storage structure being higher than that at the bottom. The research methods and conclusions in this study can provide theoretical support and reference for the multi-field coupling research on bulk grain pile storage

Compression and Fungal Heat Production in Maize Bulk Considering Kernel Breakage

Breakage in maize kernels and vertical pressure in grains lead to the uneven distribution of grain bulk density, which easily causes undesired problems in terms of grain storage. The objective of this study was, therefore, to determine the compression and heat production of the whole kernel (WK) and half kernel (HK) under two different loadings, i.e., 50 and 150 kPa, in maize bulk. An easy-to-use element testing system was developed by modification of an oedometer, and an empirical–analytical–numerical method was established to evaluate fungal heat production, considering kernel breakage and vertical pressure. Based on the experimental results, it was found that breakage induced larger compression; the compression of HK was 62% and 58% higher than that of WK at 50 kPa and 150 kPa, respectively. The creep model of the Hooke spring–Kelvin model in series can be used to accurately describe the creep behavior of maize bulk. Fungi and aerobic plate counting (APC) were affected significantly by the breakage and vertical pressure. APC in HK was 19 and 15 times that of WK under 150 and 50 kPa, respectively. The heat released by the development of fungi was found to be directly related to the APC results. The average temperatures of WK and HK under 150 and 50 kPa were 11.1%, 9.7%, 7.9%, and 7.6% higher than the room temperature, respectively. A numerical method was established to simulate the temperature increase due to fungi development. Based on the numerical results, heat production (Q) by fungi was estimated, and the results showed that the Q in HK was 1.29 and 1.32 times that of WK on average under 150 and 50 kPa. Additionally, the heat production results agreed very well with the APC results

Visualization Analysis of Cross Research between Big Data and Construction Industry Based on Knowledge Graph

Big data technology has triggered a boom in research and applications around the world. The construction industry has ushered in a new technological change in this context. Researchers have conducted in-depth research on the intersection of big data and architecture, but lack quantitative analysis and comprehensive evaluation of the research results. This article draws a series of knowledge maps with the help of the CiteSpace software using the relevant literature in the Web of Science database between 2007 and 2022 as data samples to comprehensively grasp the research development at the intersection of big data and the construction industry. The knowledge base, research hotspots, and domain evolution trends in the intersection of big data and the construction industry are analyzed quantitatively and aided by qualitative analysis through visualization, respectively. The results show that Chinese and American scholars have published more relevant papers in international journals, and some well-known universities in both countries constitute the main group of research institutions. The research hotspots are BIM, data mining, building energy saving, smart cities, and disaster prevention and damage prevention. In the future, the research on the integration and application of the construction industry with emerging technologies, such as big data, BIM, and cloud computing will be connected more closely. This study provides a preliminary overall picture of the research of big data in the field of construction by sorting out and analyzing the existing results