Field Environment Research Articles

Synthesis and Hg2+ removal ability of renewable furfurylamine-derived bio-polythioureas

Petroleum-derived polythioureas (PTUs) are typical functional polymers that have been applied as essential materials in the optoelectric and environmental fields. The design and preparation of sustainable PTUs are the current focus in this field. In the present study, we first proposed that PTUs can be prepared from bisfuran diamines by solution polymerisation with CS2 without any catalyst. The diamine monomers were prepared from renewable furfurylamine, which enabled the final PTUs to be sustainable. The highest molecular weight of the resulting PTUs was 86.64 kg/mol, with a polydispersity of 1.32. The glass transition temperature (Tg) of PTU can be tuned by changing the spacer of monomers. All synthesised PTUs showed excellent thermal stability, and the char yield at 800 °C was > 40 %. Attractively, these PTUs are excellent Hg2+ ion capturers due to their thiourea structure.

Stress Detection in IT Professionals Using Machine Learning

Abstract: In today's fast-paced technology landscape, stress management. The work environment in the IT field is often characterized by long hrs, and high expectations, which can leading to elevated stress levels. Unchecked stress not only impacts the health and well-being of professionals but also affects in job satisfaction. This study aims to predicting the stress levels of IT professionals using machine learning techniques, thereby aiding in proactive stress management. We utilize a range of features indicative of work stress, including Heart Rate, Skin Conductivity, Hours Worked, Number of Emails Sent, and Meetings Attended. These features provide a physiological and work-related factors that contribute to stress. The application of [ML] in this context serves as an innovative approach to an increasingly pertinent issue. By leveraging the power of data analytics, this model aims to organizations. Individuals we can use for self-monitoring and early intervention, while organizations can utilize them to identify high-stress environments or roles, thereby allocating resources or interventions more effectively. Our preliminary results indicate a strong correlation between the chosen features and stress levels, demonstrating the viability of using ml for stress prediction in IT professionals. This study stands as a crucial step towards a more data-driven approach to mental health condition

Foliar inoculation of Phyllachora maydis into corn induces infection and local spread in field environments.

Tar spot of corn (Zea mays L.) is a significant disease in the United States and Canada caused by Phyllachora maydis, an obligate biotroph fungus. However, field research critical for understanding and managing the disease has been hindered by a need for methods to inoculate corn with P. maydis in field environments. In this study, we developed and demonstrated the efficacy of a method to initiate tar spot in field settings using inoculations of corn leaves with P. maydis inoculum that had been stored at -20 °C for 10 months. Stromata of P. maydis were observed 19 days after inoculations in two field experiments, and stromata resulting from secondary spread were initially observed 39 to 41 days after the initial inoculations. Tar spot was not present in the fields beyond the inoculated areas or localized spread area, signifying that the establishment of initial disease resulted solely from inoculations. This study enhances our understanding of inoculation and infection of corn with P. maydis and tar spot development in field environments. The results will aid new research into understanding the corn tar spot pathosystem and improving management strategies.

Far-red emitting Li2TiO3: Cr3+ phosphor: Synthesis, luminescence properties and potential applications

The Cr[Formula: see text]-activated phosphor can emit far-red light under the excitation of an external light source, mainly due to the transition of the outermost electrons of Cr[Formula: see text] from the 2E level to the 4A2 level in a strong crystal field environment. A novel far-red Li2TiO3: Cr[Formula: see text] phosphor was prepared by the solid-state method. Under the excitation of 356[Formula: see text]nm, the Li2TiO3: Cr[Formula: see text] phosphors emit intense far-red light in 600–850[Formula: see text]nm with a central wavelength of 732[Formula: see text]nm. The emission band of all samples was matched with the absorption bands of phytochrome P[Formula: see text]. The experimental data and theoretical calculation confirmed that Cr[Formula: see text] is surrounded by a strong crystal field environment. The effect of Cr[Formula: see text] doping concentration on the luminescence intensity was analyzed. These research works demonstrate that far-red Li2TiO3: Cr[Formula: see text] phosphors have potential applications in plant growth lights.

Thermal and electric field driven rf breakdown precursor formation on metal surfaces

The phenomenon of electric breakdown poses serious challenges to the design of devices that operate in high electric field environments. Experimental evidence points toward breakdown events that are accompanied by elevated temperatures and dark current spikes, which is attributed to high-asperity nanostructure formation that enhances the local electric field and triggers a runaway process. However, the exact mechanistic origin of such nanostructures under typical macroscopic operational conditions of electric field and magnetic-field-mediated heating remains poorly understood. In this work, we simulate the evolution of a copper surface under the combined action of the electric fields and elevated temperatures. Using a mesoscale curvature-driven surface evolution model, we show how a copper surface can undergo a type of dynamical instability that naturally leads to the formation of sharp asperities in realistic experimental conditions. Exploring the combined effect of fields and temperature rise, we identify the critical regimes that allow for the formation of breakdown precursors. The results show that thermoelastic stresses, while not essential, can significantly lower the critical electric field required for runaway surface instability, which is consistent with experimental observations that thermal effects can increase breakdown rates. Published by the American Physical Society 2024

Elucidating transport dynamics and regional division of PM2.5 and O3 in China using an advanced network model

Air pollution exhibits significant spatial spillover effects, complicating and challenging regional governance models. This study innovatively applied and optimized a statistics-based complex network method in atmospheric environmental field. The methodology was enhanced through improvements in edge weighting and threshold calculations, leading to the development of an advanced pollutant transport network model. This model integrates pollution, meteorological, and geographical data, thereby comprehensively revealing the dynamic characteristics of PM2.5 and O3 transport among various cities in China. Research findings indicated that, throughout the year, the O3 transport network surpassed the PM2.5 network in edge count, average degree, and average weighted degree, showcasing a higher network density, broader city connections, and greater transmission strength. Particularly during the warm period, these characteristics of the O3 network were more pronounced, showcasing significant transport potential. Furthermore, the model successfully identified key influential cities in different periods; it also provided detailed descriptions of the interprovincial spillover flux and pathways of PM2.5 and O3 across various time scales. It pinpointed major pollution spillover and receiving provinces, with primary spillover pathways concentrated in crucial areas such as the Beijing-Tianjin-Hebei (BTH) region and its surrounding areas, the Yangtze River Delta, and the Fen-Wei Plain. Building on this, the model divided the O3, PM2.5, and synergistic pollution transmission regions in China into 6, 7, and 8 zones, respectively, based on network weights and the Girvan Newman (GN) algorithm. Such division offers novel perspectives and strategies for regional joint prevention and control. The validity of the model was further corroborated by source analysis results from the WRF-CAMx model in the BTH area. Overall, this research provides valuable insights for local and regional atmospheric pollution control strategies. Additionally, it offers a robust analytical tool for research in the field of atmospheric pollution.

Solid–Liquid Two-Phase Flowmeter Flow-Passage Wall Erosion Evolution Characteristics and Calibration of Measurement Accuracy

Solid–liquid two-phase flowmeters are widely used in critical sectors, such as petrochemicals, energy, manufacturing, the environment, and various other fields. They are indispensable devices for measuring flow. Currently, research has primarily focused on gas–liquid two-phase flow within the flowmeter, giving limited attention to the impact of solid phases. In practical applications, crude oil frequently contains solid particles and other impurities, leading to equipment deformation and a subsequent reduction in measuring accuracy. This paper investigates how particle dynamic parameters affect the erosion evolution characteristics of flowmeters operating in solid–liquid two-phase conditions, employing the dynamic boundary erosion prediction method. The results indicate that the erosion range and peak erosion position on the overcurrent wall of the solid–liquid two-phase flowmeter vary with different particle dynamic parameters. Erosion mainly occurs at the contraction section of the solid–liquid two-phase flowmeter. When the particle inflow velocity increases, the erosion range shows no significant change, but the peak erosion position shifts to the right, primarily due to the evolution of the erosion process. With an increase in particle diameter, the erosion range expands along the inlet direction due to turbulent diffusion, as particles with lower kinetic energy exhibit better followability. There is no significant change in the erosion range and peak erosion position with an increase in particle volume fraction and particle sphericity. With a particle inflow velocity of 8.4 m/s, the maximum erosion depth reaches 750 μm. In contrast, at a particle sphericity of 0.58, the minimum erosion depth is 251 μm. Furthermore, a particle volume fraction of 0.5 results in a maximum flow coefficient increase of 1.99 × 10−3.

Experimental study of fouling characteristics of CaCO3 precipitated crystal scale mixed with different particles in an alternating magnetic field environment

This paper is to study the effect of CaCO3 precipitated crystal scale mixed with different particles on the scaling characteristics under the action of electromagnetic field. The simulation of industrial field experiments, based on the electromagnetic water treatment dynamic experimental bench, change the type of particles, concentration, magnetic field strength, according to the experimental results of the thermal resistance and scale inhibition rate curve under different working conditions, through the scanning electron microscope microscopy analysis of the fouling samples, to study the effect of CaCO3 fouling mixed with different particles in the role of the magnetic field on the effect of the law on the deposition characteristics.The results show that: electromagnetic field on MgO particles dirt and CaCO3 dirt deposition have inhibition effect; CaCO3 and different concentrations of CaCO3 crystalline particles mixed, CaCO3 particles, the more the electromagnetic field on the formation of CaCO3 precipitation scale inhibition effect is not obvious; CaCO3 precipitation scale and MgO particles mixed in the magnetic field can significantly enhance the effect of the field of the inhibition of the scale, magnetic field Under the action of the magnetic field, as the content of MgO particles increases, the scale inhibition effect on the dirt is first enhanced and then weakened until it tends to be about 0. Scanning electron microscopy analyses showed that the morphology and degree of aggregation of calcium carbonate fouling crystals were influenced by MgO particles under the action of electromagnetic fields, and CaCO3 fouling was transformed from regular ortho-hexahedra to acicular aragonite and amorphous CaCO3, which made the stripping phenomenon more significant.Comprehensive experimental results and scanning electron microscopy analyses of fouling samples show that the mixture of CaCO3 solution with a small amount of MgO particles can be an effective means to inhibit the precipitation of crystalline fouling under the environment of alternating electromagnetic field. This study provides theoretical guidance for the application of alternating magnetic field in the future, and provides new ideas and methods for solving the problem of crystalline fouling in industry.

UAV-Based Environmental Magnetic Field Measurement Method Using a TMR Sensor

UAV-Based Environmental Magnetic Field Measurement Method Using a TMR Sensor

Intraspecific plant-soil feedback in four tropical tree species is inconsistent in a field experiment.

Soil microbes can influence patterns of diversity in plant communities via plant-soil feedbacks. Intraspecific plant-soil feedbacks occur when plant genotype leads to variations in soil microbial composition, resulting in differences in the performance of seedlings growing near their maternal plants versus seedlings growing near nonmaternal conspecific plants. How consistently such intraspecific plant-soil feedbacks occur in natural plant communities is unclear, especially in variable field conditions. In an in situ experiment with four native tree species on Barro Colorado Island (BCI), Panama, seedlings of each species were transplanted beneath their maternal tree or another conspecific tree in the BCI forest. Mortality and growth were assessed at the end of the wet season (~4 months post-transplant) and at the end of the experiment (~7 months post-transplant). Differences in seedling performance among field treatments were inconsistent among species and eroded over time. Effects of field environment were detected at the end of the wet season in two of the four species: Virola surinamensis seedlings had higher survival beneath their maternal tree than other conspecific trees, while seedling survival of Ormosia macrocalyx was higher under other conspecific trees. However, these differences were gone by the end of the experiment. Our results suggest that intraspecific plant-soil feedbacks may not be consistent in the field for tropical tree species and may have a limited role in determining seedling performance in tropical tree communities. Future studies are needed to elucidate the environmental and genetic factors that determine the incidence and direction of intraspecific plant-soil feedbacks in plant communities.

Ultracold atomic spin mixtures in ultrastable magnetic field environments

Abstract Ultracold atomic spin mixtures develop rich and intriguing magnetic properties when external radiation coherently couples different spin states. In particular, the coupled mixture may acquire a critical behavior when the spin interactions equal the coupling energy. 
However, atomic mixtures generally feature a relatively high sensitivity to magnetic fields that can set a limitation to the observable phenomena.
In this article, we present an overview of experimental studies of magnetism based on superfluid multicomponent gases in an ultrastable magnetic field environment, which recently became available.

Mapping Trends on Employee Performance and Work Environment: A Bibliometric Analysis

Employee performance and work environment are two key elements in the success of an organization. The relationship between employee performance and the work environment has become a major focus for many organizations to improve productivity, employee satisfaction, and overall organizational performance. This study aims to determine the development of research with the theme Employee Performance and Work Environment in the range of 2014 to 2023 through the help of the Vosviewers application in visualizing data. The method used in this study is qualitative research with a literature study approach. As for the data found, 98 documents were obtained and analyzed. These datasets are converted to CSV format, BibTeX, and RIS format and imported into bibliophilia for bibliometrics and analysis. The results showed that 2023 is the year with the highest number of publications on the topic of Employee Performance and Work Environment. Indonesia is the country that influences scientific publications the most. Samani, S.A. is the most prolific writer with 3 documents in the field of Employee Performance and Work Environment. Great potential for further research in areas such as Compensation, leadership, training, work-life balance, and work engagement, which still has the potential to be explored more deeply in the context of Employee Performance and Work Environment.

The elimination of two restriction enzyme genes allows for electroporation-based transformation and CRISPR-Cas9-based base editing in the non-competent Gram-negative bacterium Acinetobacter sp. Tol 5

ABSTRACT Environmental isolates are promising candidates for new chassis of synthetic biology because of their inherent capabilities, which include efficiently converting a wide range of substrates into valuable products and resilience to environmental stresses; however, many remain genetically intractable and unamenable to established genetic tools tailored for model bacteria. Acinetobacter sp. Tol 5, an environmentally isolated Gram-negative bacterium, possesses intriguing properties for use in synthetic biology applications. Despite the previous development of genetic tools for the engineering of strain Tol 5, its genetic manipulation has been hindered by low transformation efficiency via electroporation, rendering the process laborious and time-consuming. This study demonstrated the genetic refinement of the Tol 5 strain, achieving efficient transformation via electroporation. We deleted two genes encoding type I and type III restriction enzymes. The resulting mutant strain not only exhibited marked efficiency of electrotransformation but also proved receptive to both in vitro and in vivo DNA assembly technologies, thereby facilitating the construction of recombinant DNA without reliance on intermediate Escherichia coli constructs. In addition, we successfully adapted a CRISPR-Cas9-based base-editing platform developed for other Acinetobacter species. Our findings provide genetic modification strategies that allow for the domestication of environmentally isolated bacteria, streamlining their utilization in synthetic biology applications. IMPORTANCE Recent synthetic biology has sought diverse bacterial chassis from environmental sources to circumvent the limitations of laboratory Escherichia coli strains for industrial and environmental applications. One of the critical barriers in cell engineering of bacterial chassis is their inherent resistance to recombinant DNA, propagated either in vitro or within E. coli cells. Environmental bacteria have evolved defense mechanisms against foreign DNA as a response to the constant threat of phage infection. The ubiquity of phages in natural settings accounts for the genetic intractability of environmental isolates. The significance of our research is in demonstrating genetic modification strategies for the cell engineering of such genetically intractable bacteria. This research marks a pivotal step in the domestication of environmentally isolated bacteria, promising candidates for emerging synthetic biology chassis. Our work thus significantly contributes to advancing their applications across industrial, environmental, and biomedical fields.

Plant-assisted green preparation of silver nanoparticles using leaf extract of Dalbergia sissoo and their antioxidant, antibacterial and catalytic applications.

Plant-mediated preparation of silver nanoparticles (AgNPs) is thought to be a more economical and environmentally benign process in comparison to physical and chemical synthesis methods. In the present study, the aqueous leaf extract of Dalbergia sissoo was prepared and utilized to reduce silver ion (Ag+) during the green synthesis of silver nanoparticles (DL-AgNPs). The formation of DL-AgNPs was verified using UV-Vis spectra, exhibiting the surface plasmon resonance (SPR) band at around 450nm. FT-IR analysis revealed the kinds of phytochemicals that serve as reducing and capping agents while DL-AgNPs are being synthesized. Analysis of scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM) images verified the development of spherical and oval-shaped DL-AgNPs, with sizes ranging from 10 to 25nm. The stability and particle size distribution of synthesized DL-AgNPs were ensured by zeta potential and DLS (dynamic light scattering) investigations. Additionally, X-ray diffraction (XRD) analysis confirmed the crystalline nature of DL-AgNPs. In antioxidant experiments, DL-AgNPs demonstrated significant scavenging capacities of DPPH and ABTS radicals with EC50 values of 51.32 and 33.32μg/mL, respectively. The antibacterial activity of DL-AgNPs was shown to be significant against harmful bacteria, with a maximum zone of inhibition (21.5 ± 0.86mm) against Staphylococcus aureus. Furthermore, DL-AgNPs exhibited effective catalytic activity to degrade environment-polluting dyes (methylene blue, methyl orange, and Congo red) and toxic chemicals (p-nitrophenol). The results of all these studies suggested that DL-AgNPs made from the leaf extract of Dalbergia sissoo have merit for application in the environmental and biomedical fields.

Driving mechanisms and hydro‐chemical variation for assessing salt‐induced weathering of sandstone in grotto relics

AbstractSalt weathering is considered as one of the most damaging processes acting on cultural heritage sites and salt crystallization significantly contributes to the deterioration of natural sandstone in grotto relics. A laboratory partial immersion experiment was carried out to elucidate how humidity influences the salt‐induced weathering in grotto relics. Field environmental observations at the Yungang Grottoes were conducted to evaluate the differences between experimental endeavours and field observations. Superficial salt accumulation was characterized by hydro‐chemical and quantitative atomistic analysis. It revealed the co‐existence of calcium sulphate and magnesium sulphate, with a Ca/Mg molar ratio of 0.27 at RHam and 4.13–18.15 at a constant RH. An average increase of 165 mg/L in Na+ concentration and 120.7 mg/L in Mg2+ concentration in the groundwater was detected after immersion, which was attributed to the dissolution of the sandstone rock. The reduction of 322.5 mg/L in the SO42− concentration in the groundwater after partial immersion shows that capillary forces influence the migration of SO42− from the immersion solution. Calcium sulphate and magnesium sulphate accumulation with a Ca/Mg molar ratio of 0.03–0.17 in the field environment is strongly correlated with the occurrence of salt efflorescence. The upward transport of soluble salt was driven by capillary forces after partial immersion in the groundwater collected from the Yungang Grottoes. It then migrated from the interior to the exterior of the sandstone specimen due to evaporation. Salt efflorescence formed on the upper exposed stone close to the capillary fringe owing to the combined effects of condensation, hygroscopicity and evaporation. These processes were driven by wetting–drying and dissolution–crystallization cycles in response to fluctuating environmental conditions. These results contribute to a better understanding the mechanism of salt‐induced weathering and provide a basis for future conservation to mitigate the harmful impact of salts in heritage sites.

Nigerian Land Resources and Conservation Strategies: A Critical Analysis of Economic and Non-Economic Issues

Land is an indispensable resource for all of man’s activities, and being an asset with zero elasticity in its physical supply requires adequate sustainability and conservation. Over the years, various strategies have been generated and adopted to ensure conservative management of land resources. This paper examines Nigerian land resources and conservation strategies, critically analyzing the economic and non-economic issues. Land resources conservation in Nigeria indulges economic issues from agriculture, urbanization and industrialization which affect the availability and accessibility of land for various uses, while the non-economic issues from cultural, social and environmental factors and policies are basically concerned with the determination and control of the use of land resources. These have to be considered with emanating challenges and surmounted to ensure land resources conservation for sustainability considering future generations. Policymakers, researchers and stakeholders in the environmental field have to work and operate in synergy, evaluating workable and favourable conservation strategies: balancing economic and non-economic land related issues to achieve overcoming emanating issues, thereby sustaining the goal of Land resources conservation in Nigeria.

Dynamic Analysis of an FGM Beam Undergoing Large Overall Motion in Temperature Field

The dynamic analysis of a functionally gradient material (FGM) beam undergoing large overall motion based on meshless methods is studied in the variable temperature field environment. Considering the high-order terms of nonlinear coupling deformation which were often ignored in previous studies, the high-order rigid–flexible coupled (HOC) dynamic model of a rotating FGM beam with a lumped mass in a temperature field is established by employing Lagrange’s equations of the second kind. Compared with the first-order approximate coupled (FOAC) dynamic model, the HOC dynamic model is more accurate and has a wider scope of application. The validity of the point interpolation (PIM) method and radial point interpolation method (RPIM) in this paper is verified by comparison with simulation results of the assumed mode method (AMM) and the finite element method (FEM). On this basis, the factors affecting the dynamic characteristics of the FGM beam such as the form of temperature field, the functionally gradient index, and the location of added lumped mass are discussed. In this paper, the meshless method with higher computational efficiency and the HOC dynamic model with more accurate results are adopted. This study will provide guidance and reference for dealing with problems in engineering, machinery, aerospace, and other fields in complex environment.

Genetics of phenological development and implications for seed yield in lentil.

Understanding phenology, its genetics and agronomic consequences, is critical for crop adaptation. Here we aim at (1) characterising lentil response to photoperiod with a focus on five loci: the lentil ELF3 ortholog Sn, two loci linked to clusters of lentil FT orthologs and two loci without candidates in chromosomes 2 and 5 (exp. 1: 36 lines, short and long day in phytotron); (2) establishing phenology-yield relationship (exp. 2: 25 lines, 11 field environments). A vintage perspective, where we quantify time trends in phenotype over three decades of breeding, links both experiments. Yield increased linearly from older to newer varieties at 29kg ha-1 yr-1 or 1.5% yr-1, correlated negatively with flowering time in both winter- and summer-rainfall regimes, and decoupled from biomass in favourable environments. Time to flowering shortened from older to newer varieties at -0.56 % yr-1 in the field, and -0.42 % yr-1 (short day) and -0.99 % yr-1 (long day) in the phytotron. Early-flowering lines of diverse origin carried multiple early alleles for the five loci, indicating that at least some of these loci affect phenology additively. Current germplasm primarily features the early flowering haplotype for an FTb cluster region, hence the potential to increase phenological diversity with yield implications.

Is the past recoverable from the data? Pseudoproxy modelling of uncertainties in palaeoecological data

Is the past recoverable from the data? Pseudoproxy modelling of uncertainties in palaeoecological data

Effects of long-term exposure of NSM CFRP-to-concrete bond to natural and accelerated aging environments

Carbon fiber reinforced polymer (CFRP) composites can be used to strengthen existing reinforced concrete (RC) structures. The CFRP laminate can be bonded to RC structure using epoxy adhesive via near-surface mounted (NSM) strengthening technique. However, existing literature generally lacks data about durability of NSM CFRP-to-concrete bond. In this study, strengthened concrete elements were exposed to laboratory-controlled environments (at approximately 20 °C/55 % RH, and water immersion at 20 °C) and natural field environments (to promote natural aging induced mainly by carbonation, high temperatures, freeze–thaw attack, and airborne chlorides) for up to four years. Durability tests were conducted yearly for the bond and its constituent materials. The highest bond strength degradations were nearly 12 % and 9 % for the specimens immersed in water and those exposed to freeze–thaw attack, respectively. Besides, environmental conversion factors of 0.88 and 0.93 were derived from a database of existing accelerated, and natural aging data from the present work, respectively.