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Passive IoT-based positioning systems are low-cost and taggable, making them suitable for scenarios that require the positioning of a large number of targets. Traditional passive IoT positioning is mostly applied to indoor scenarios such as asset management, material tracking. With the emergence of cellular passive IoT, passive IoT positioning technology will have a broader range of applications. On the basis of analyzing the principles and characteristics of different positioning technologies, the latest research progress of passive IoT positioning was introduced, and the passive IoT positioning technologies were summarized into three categories: geometrical measurement-based positioning methods, fingerprint feature-based positioning methods, and imaging technology-based positioning methods, according to their implementation principles. In view of the fact that most of the current research adopted the data obtained under the traditional passive IoT architecture and protocol for localization, the future development direction of passive IoT positioning technology was analyzed from three dimensions: architectures, protocols and data. The aim is to provide new ideas for researching passive IoT positioning technology.

The rapid growth of the alumina industry has significantly increased red mud production, with each ton of alumina yielding 0.8 to 1.5 tons of this byproduct. Red mud is a highly alkaline residue produced during bauxite refining, containing various metals including chromium (Cr) and vanadium (V), which pose significant environmental risks if not properly treated. Effective management and valorization of red mud are essential to mitigate environmental contamination and exploit its economic potential. Phytomining, a bioremediation strategy utilizing hyperaccumulator plants, offers a promising method for extracting economically valuable metals from red mud. This study investigates the phytomining capacity of Jatropha curcas and Sansevieria trifasciata to uptake Cr and V from red mud amended with a 5% sludge-manure mixture. The experiment was conducted over a 28-day period, during which both species were cultivated in red mud media with the amendment. The phytomining capacity of the plants was determined by measuring the metal accumulation, analyzed on days 0, 14, and 28 using acid digestion and ICP-OES analysis. Results showed that both plant species preferentially accumulated metals in their root systems rather than in their aerial parts. Jatropha curcas absorbed 1.6 mg/kg of Cr and 2.9 mg/kg of V, while Sansevieria trifasciata exhibited higher uptake, with 2.5 mg/kg of Cr and 4 mg/kg of V. These findings highlight the phytomining potential of these species in recovering valuable metals from red mud.

The highly alkaline nature of red mud, coupled with the presence of heavy metals, represents a significant environmental risk. Phytomining has the potential to facilitate the extraction of heavy metals, including vanadium (V) and chromium (Cr), from red mud. In this study, phytomining employs the use of Cymbopogon citratus and Portulaca grandiflora plants. The objective of this study is to evaluate the capacity of both plants to engage in phytomining and extract valuable metals from red mud. The methodology employed in this study entails the incorporation of stimulants in the form of manure at concentrations of 0%, 5%, and 10%. The study was conducted over a period of 28 days, during which time toxicity testing and the phytomining ability of the two plants were observed. The phytomining capacity of the plants was determined by measuring the concentration of vanadium (V) and chromium (Cr) in the plant extractions using inductively coupled plasma-optical emission spectroscopy (ICP-OES) equipment. The findings indicated that the Cymbopogon citratus and Portulaca grandiflora plants were capable of surviving on a red mud medium with the addition of 10% manure. The highest absorption of V metal was observed in Cymbopogon citratus, with a value of 23.3 mg/kg, when 10% manure and 90% red mud were added. The highest absorption of Cr metal was 18.02 mg/kg by Portulaca grandiflora with the addition of 10% manure and 90% red mud. Therefore, the results demonstrated that the addition of 10% manure enhanced the capacity of plants to absorb metals.

The increasing amount of annual red mud generation is becoming a global concern because of the environmental problems caused by its high metal content, alkalinity, and salinity. To manage red mud deposits, various green technologies have been implemented, such as phytoremediation and bioremediation. Accordingly, this study aimed to assess the morphological features of indigenous microbes in bauxite residue disposal areas (BRDA) in Indonesia. Using Gram staining method and microscopic analysis, indigenous microbial species were characterised based on morphological features such as colony profile, colour, size, margin, elevation and cell shape. As many as 10 isolates of indigenous microbes were successfully identified. All isolated were Gram positive and mostly white. The shape of colonies varied from irregular, circular, and filamentous with flat elevation, whereas the cell shape was identified as rod-shape and round-shape. Based on the similarity of the morphological characteristics of these microbes, there are five suspected genus, i.e., Micrococcus, Microbacterium, Bacillus, Cylindrogloea, Eubacterium, and Staphylococcus.

Objective To investigate the clinical effect of concentrated growth factor (CGF) applied in guided bone regeneration (GBR) for severe bone deficiency in the anterior maxilla. Methods Forty patients with bone defects in the anterior maxilla were chosen to be treated with GBR, 20 patients were treated with CGF applied in GBR as the observation group, and the other 20 patients were treated only with GBR as the control group. The evaluation of wound healing was performed after the operation, and bone augmentation was evaluated half a year after the operation. Results The first-stage healing rate of soft tissue wounds in the observation group was 100% and 75% in the control group, and the primary healing rate in the observation group was better than that in the control group (P=0.017). The changes in bone width of the observation group were （3.70 ± 0.28） mm, and those of the control group were （2.96 ± 0.16） mm. The bone augmentation in the observation group was higher than that in the control group (P=0.000). Conclusion CGF applied in GBR has a good effect on bone augmentation for severe bone deficiency in the anterior maxilla.

With the development of modern information technology, the three-dimensional design technology is widely applied in the substation engineering design of State Grid Corporation of China, and will run through the whole process of the power grid, effectively promoting the management of the substation engineering full life cycle.This paper analyzes the application scope of three-dimensional design in substation engineering is studied in depth, and the future application development is prospected, which provides a reference for the development direction of three-dimensional design in the future.

As an emerging learning platform, game-based immersive virtual reality learning environments (GIVRLEs) have the potential to solve difficult teaching problems. This study designed a GIVRLE by integrating knowledge of quadratic functions into gameplay. Forty seventh graders who had never acquired that knowledge played the game and took pre- and posttests. An additional 60 seventh graders took the same math tests as controls. The results showed significant improvements in math achievement and learning motivation between the pre- and posttests among students who played the game. No enhancement of math achievement was found in the control students. The playability survey and user experience questionnaire verified the suitability of the game. The findings indicate that a GIVRLE is a suitable tool for addressing teaching difficulties in K-12. The notion of intrinsic integration between learning content and gameplay based on simulated daily activity tasks is further discussed.