A Review of Range-based RSSI Algorithms for Indoor Wireless Sensor Network Localization

The secure localisation of unknown nodes in Wireless Sensor Networks (WSNs) is a crucial research topic due to the vast range of applications of WSNs. These applications drive the development of WSNs, as real-world obstacles typically motivate them. WSN technology is rapidly evolving, and this paper provides a brief overview of WSNs, including key research findings on energy conservation and node deployment. The paper discusses the applications of WSNs in medical health, environment and agriculture, intelligent home furnishing and construction, and military, space, and marine exploration. The paper focuses on the research of RSS-based locating algorithms in WSNs and is divided into two sections. Firstly, accurate location depends on the accurate RSSI received from nodes. This experiment analyses the distribution trend of RSSI and derives the loss model of signal propagation by processing experimental data. Secondly, Gaussian fitting calculates the distance between receiving and sending nodes by processing individual RSSI at different distances. The primary challenge in studying this RSSI range-based technique is the low positioning accuracy, low energy, and high error rate. To solve this problem, a recommended GA is used to find the optimal site by minimising error, providing the best feasible solution, and being energy-sensitive, with accuracy based on the least error inside the network. The proposed approach aims to optimise sensor placements for improved performance

Effect of Fast-Growing Trees on Soil Properties and Carbon Storage in an Afforested Coal Mine Land (India)

Surface coal mining activities have numerous consequences on terrestrial ecosystems. Loss of soil and biomass carbon pool due to mining activities is a serious concern in the rapidly changing environment. We investigated the effect of fast-growing trees (Albizia lebbeck, Albizia procera, and Dalbergia sissoo) on soil fertility and ecosystem carbon pool after eight years of afforestation in the post-mining land of Jharia coalfield, India, and compared with the adjacent natural forest site. Significant differences in soil organic carbon (SOC) and total nitrogen (TN) stocks in afforested mine soil and natural forest soils were observed. Greater SOC stock was found under D. sissoo (30.17 Mg·C·ha−1) while total N stock was highest under A. lebbeck (4.16 Mg·N·ha−1) plantation. Plant biomass accumulated 85% of the natural forest carbon pool after eight years of afforestation. The study concluded that planting fast-growing trees in post-mining lands could produce a promising effect on mine soil fertility and greater carbon storage in a short period

Development of dust ignition protected electrically powered forklift truck for combustible dust environment

Industries dealing with explosive gases and combustible dusts in processing or production are always at higher risk of gas or dust explosion. Purified terephthalic acid (PTA) plant of Indian Oil Corporation Ltd. (IOCL), Panipat, India has similar risk of dust explosion hazard, since PTA is a combustible substance in the form of dust or layer. To load, unload and transport the PTA bags in the plant, special forklift trucks are required. A prototype forklift truck for combustible dust atmosphere was developed in collaboration with M/s Action Construction Equipment Ltd. (ACE), Palwal, India. The electrical components with dust ignition protected design have been manufactured by ACE in consultation with CSIR-CIMFR, Dhanbad, India. All other possible sources of ignition are identified and suitable components/parts of forklift are used for hazardous atmosphere. This paper presents the design requirements of a dust ignition protected and battery operated forklift truck for safe use in zone 22 combustible dust atmosphere of the plant

Plant carbon inputs through shoot, root, and mycorrhizal pathways affect soil organic carbon turnover differently

Plant carbon (C) inputs via shoot, roots, and the associated mycorrhizal fungi are vital drivers of soil organic C (SOC) stock and turnover. Both the amounts and proportions of plant C inputs to the soil through these pathways can be affected by soil fertility. Yet, we know little about how divergent pathways of plant C inputs contribute to SOC cycling under different soil fertility. By growing the C4 grass Cleistogenes squarrosa in C3 soils, we quantified the contributions of shoot, roots, and arbuscular mycorrhizal fungi (AMF) to SOC turnover with different fertility in a temperate grassland. Our four-year field experiment showed that soils with higher fertility sequestered more shoot-, root- and AMF-derived C, which were mainly driven by greater soil microbial biomass. Irrespective of soil fertility, roots contributed the most (44%) to new SOC formation, while shoot (28%) and AMF (28%) exerted similar but lower contributions. We found that the positive priming effects induced by roots and AMF were greater in more fertile soils, which were primarily associated with more root- and AMF-derived C, respectively. Across all the soil fertility levels, root pathway had an equal impact on new SOC accumulation and native SOC losses via priming effects, and thus caused no net SOC changes. However, the priming effect induced by AMF pathway was 60% higher than the root pathway across treatments. The disproportionately large priming effects relative to new SOC accumulation induced by AMF led to net SOC losses, especially in soils with higher fertility. Overall, we demonstrated that plant C inputs through shoot, root, and mycorrhizal pathways have differential impacts on SOC turnover. Our quantitative estimation should be valuable for more accurately modeling how much plant-derived C can be sequestered in the soils and advancing our understanding of future SOC dynamics under global changes

Biological indicators affected by land use change, soil resource availability and seasonality in dry tropics

Land use change (LUC) in tropics, explicitly from forest to conventional agriculture, is negatively affecting soil health and productivity. However, effect of such LUC on soil biological properties are poorly known in dry tropical environment. This study aimed to determine the impact of such LUC and climate seasonality on soil biological properties (microbial and enzyme activities), and to also explore the role of soil resources (C, N and P) in driving soil biological properties during this environmental change. Soil biological indicators of topsoil (0-15 cm) were measured on a seasonal basis in the natural forest, fallow and agricultural land. Soil microbial biomass C (C-mic), CO2 efflux (C-efflux) and hydrolytic enzyme activities (acid phosphatase, alkaline phosphatase, beta-glucosidase, dehydrogenase, fluorescein diacetate) were generally higher in the forest followed agriculture and fallow. The lower level of these biological variables in agriculture soils were possibly due to lower total soil organic carbon (SOC), labile SOC (particulate OC; POC), total N and P, and cropping disturbance (i.e., fertilization) induced higher inorganic N and P. Whereas, lower biological activities in fallow soils were mainly attributed lower plant activity (i.e. litter production and root activity). In contrast, oxidative enzyme (particularly peroxidase) activities were higher in agriculture followed by the forest and fallow, which might be attributed to higher soil oxygenation from tillage in agriculture and higher persistent SOC (non-particulate OC; NPOC). Seasonal variation in soil biological properties was identical among land uses, though its extent was greater in the forest than fallow and agriculture, indicating LUC can alter the degree of seasonality in biological properties. In addition, the higher specific enzyme activities (i.e., enzyme activities per unit of C-mic) and microbial metabolic quotient (qCO(2)) in the fallow followed by agriculture and forest, indicating the higher degree of stress on soil microbes after the deforestation than cropping. Whereas, the higher specific enzyme activities and qCO(2) in agriculture possibly attributed to higher microbial nutrients demand and lower SOC accumulation. Collectively, our results reveal the significant effects of deforestation and agriculture on soil biological activities and improve our understanding of the potential mechanism driving these effects

Soil Water Depletion in Planted Alfalfa Pastures in an Alpine Pastoral Area

This article belongs to the Special Issue Soil and Water Conservation in Agricultural and Forestry Systems.Alfalfa (Medicago sativa) has strong stress resistance, high nutritional value, good palatability for cattle, high yield and a drought tolerance mechanism, but long-term planting leads to soil desiccation. This research was carried out to examine the soil water conditions of alfalfa pastures with different planted ages, and determine the optimum time for alfalfa rotation in a plateau area of a sub-alpine monsoon climate. Soil water depletion, soil compaction and vegetation characteristics of alfalfa pastures of different ages (i.e., two, four and seven years) were assayed and compared with those of a cornfield which served as the control crop. Three 20 × 20 m plots and five random quadrats per plot were established at each field. Soil water contents at 0–400 cm depth and plant biomass were compared among different vegetation types, soil transects and planting years. The results showed that at the 250–400 cm depth, the soil water storage of the four- and seven-year-old alfalfa pastures was much lower than in the two-year-old alfalfa pasture and in the cornfield. Moreover, the degree of soil water storage deficit of the four- and seven-year-old alfalfa pastures was much higher than in the other fields. Soil compaction of alfalfa pastures increased with increasing planting age and reached a peak value in the seven-year-old alfalfa pasture. The highest above-ground biomass was observed in the four-year-old alpine alfalfa pasture. Thus, the best cultivation period for alfalfa pastures was four years from the perspective of higher yield and lower soil water consumption in pastoral sub-alpine areas. This study provided a basis for sustainable alfalfa pasture cultivation, timely harvest, rotation and water management measures to be implemented in alpine grazing lands.This research was funded by the National Natural Science Foundation of China (NSFC41722107, 31372368), the Light of West China Program (XAB2015A04), the Youth Innovation Promotion Association (2011288) of the Chinese Academy of Sciences, and the Youth Talent Plan Foundation of Northwest A&F University (2452018025)