The paper lays out basic design options for infrastructure policy. It first sketches mechanisms to assess demand. Then it sets out a hierarchy of issues starting with choice of market structure followed by conduct regulation. Ownership options are largely a function of market structure choices. The implications for finance—the topic of much day-to-day discussion in infrastructure policy-making—follow from these various prior choices. The discussion naturally circumscribes the role for the so-called public-private partnerships, their uses and pitfalls.

This study aimed to analyze government policies in education during the Covid-19 pandemic and how teachers exercised discretion in dealing with limitations in policy implementation. This research work used the desk review method to obtain data on government policies in the field of education during the Covid-19 pandemic. In addition, interviews were conducted to determine the discretion taken in implementing the learning-from-home policy. There were three learning models during the pandemic: face-to-face learning in turns (shifts), online learning, and home visits. Online learning policies did not work well at the pandemic’s beginning due to limited infrastructure and human resources. To overcome various limitations, the government provided internet quota assistance and curriculum adjustments and improved online learning infrastructure. The discretion taken by the teachers in implementing the learning-from-home policy was very dependent on the student’s condition and the availability of the internet network. The practical implication of this research is that street-level bureaucrats need to pay attention to discretionary standards when deciding to provide satisfaction to the people they serve.

This work presents the evaluation of iron oxide nanoparticles obtained from the aqueous extract of Eucalyptus grandis. Twenty-three experiments were carried out where the synthesis of nanoparticles was performed by using the aqueous extract together with salts of iron (II) chloride tetrahydrate and iron (III) chloride hexahydrate. A characterization was carried out by IR, TEM and BET, where bands were presented at 3,440.77, 1,559.26 and 445.31 cm⁻¹, indicating the presence of iron oxide nanoparticles. A relatively high monodispersity was evidenced with particles around 9 nm. By means of BET analysis it was found to present a surface area of 131.897 m²/g. Obtaining nanoparticles by this green method presents yield values of 98%, with application in nanotechnology, biomedicine, environmental treatment, among others, making them highly versatile and their production cost is relatively low.

This paper mainly discusses the application and impact of AI tools in vocational college students' career planning and employment preparation in Chinese Mainland. Through a review and analysis of relevant literature, this article found that artificial intelligence tools can provide students with more information and assistance, thereby improving their career cognition and employment competitiveness. However, if artificial intelligence tools are not open to Chinese users or students overly rely on these tools, it may also bring some negative effects, such as job anxiety and decreased self-awareness. Therefore, the government and teaching departments should strengthen the education of career planning and employment preparation, improve the artificial intelligence system, establish personalized service mode and other measures to provide more comprehensive and personalized career recommendation and employment services for higher vocational students in Chinese Mainland.

In order to optimize the environmental factors for cucumber growth, a fertilizer and water control system was designed based on the Internet of Things (IoT) system. The IoT system monitors environmental factors such as temperature, light and soil Ec value, and uses image processing to obtain four growth indicators such as cucumber stem height, stem diameter size, number of leaves and number of fruit set to establish a single growth indicator model for temperature, light, soil Ec value and growth stage, and the four growth indicators were fused to obtain the comprehensive growth indicator I_c for cucumber, and calculates its deviation to determine the cucumber growth status. Based on the integrated growth index I_c of cucumber, a soil Ec control model was established to provide the optimal environment and fertilizer ration for cucumber at different growth stages to achieve stable and high yield of cucumber.