Influence Of Micro Research Articles

Influence of micro- and nano-plastics on phenanthrene adsorption at the root-water interface

The adsorption of organic pollutants onto plant root surfaces is an initial crucial stage in the transfer of these pollutants from aqueous or soil solutions to plant systems. This study explored the potential influence of micro- and nano-plastics (MNPs) (0.1–100 μm) on the process of phenanthrene (Phe) adsorption at the root–water interface. The findings indicate that MNPs can exhibit either promotional or inhibitory effects on the root adsorption of organic pollutants, depending on both their particle size and content. Specifically, both the sorption capability of MNPs for Phe and their tendency to accumulate on or within root tissues increase with decreasing particle size. These dual effects facilitate the accumulation of nanoscale MNPs (0.1–6 μm in this work) within roots, which function as efficient carriers for Phe and increase Phe accumulation in root tissues. In contrast, MNPs with larger particle sizes (1–100 μm in this work) exhibit reduced affinity for roots and are more prone to remain in solution, thereby exerting more pronounced competitive inhibition against the adsorption of Phe by roots. However, when the concentration of nano-plastics in the rootwater system exceeded the retention capacity of the roots, the excess nano-plastics could compete with the roots for Phe, potentially reducing overall Phe sorption by the roots. These conditional effects of MNPs as either competitors or facilitators (vectors) in the root adsorption processes of organic pollutants may account for the different roles observed in previous studies where MNPs exhibited varying effects on the plant accumulation of organic pollutants.

Influence of micro- and macroscopic tool features and errors within one batch in end milling

Among other things the tool geometry influences the accuracy of the machined part, the chip formation and the process forces in end milling. The tool geometry can be divided into two different features: the micro and the macro geometry. The micro geometry describes the shape of the cutting edge and can influence the process forces, tool life and surface quality. The macro geometry describes the general specification of the tool as well as the runout. The runout can also affect process forces, tool life and the surface topography. This study shows that the micro and macro geometry of end mills of the same specification can vary significantly in one batch. This also has an influence on the process forces and resulting surface topography in end milling processes.

Electrical surface breakdown characteristics of micro- and nano-Al2O3 particle co-doped epoxy composites

Abstract Epoxy microcomposites are basic materials for gas-insulated switchgear (GIS) spacers that are subjected to huge electrical stress. Previous works have indicated that nanoparticles are beneficial to dielectric performance. However, surface electrical breakdown, a typical fault in GIS of co-doped micro- and nanoparticles in epoxy composites, is seldom studied. In this work, numerous concentrations of micro- and nano-Al2O3 are co-doped into an epoxy matrix; the surface traps, surface charging, and surface breakdown voltages (V sb) of the co-doped composites are studied, and the influence of micro- and nano-Al2O3 on the electrical surface breakdown is clarified. The results show that V sb first decreases and then increases with the microparticles, and V sb decreases from 25.34 kV to 19.52 kV. As the number of nanoparticles increases, V sb increases and then decreases when the microparticle loading is low, but decreases and then increases when the microparticle loading exceeds 40 wt%. Micro-Al2O3 particles introduce surface shallow traps into epoxy composites, while small amounts of nano-Al2O3 introduce deep traps. Two different mechanisms dominate the surface charging and V sb of epoxy micro-nanocomposites. When the surface conductivity is lower than 7 × 10−14 S, the surface charges are reduced by the suppression of electrode injection as the trap depth increases, and V sb increases. When the surface conductivity exceeds 7 × 10−14 S, the surface charge dissipation rate increases with the surface conductivity and V sb increases as the surface conductivity increases. Our work indicates that co-doped micro- and nano-particles should keep the surface conductivity away from the specic value (7 × 10−14 S) to safeguard insulation properties for GIS spacers.

Why do Indian exporting firms borrow in foreign currency?

Purpose Since the liberalization policy of 1991, India has focused on export-led growth. However, the performance of international trade remains poor. This study aims to examine the role of credit constraints on the choice of Indian manufacturing firms to borrow in foreign currency. First, it explores the role of export activities in foreign currency borrowing (FCB). Second, it investigates how credit constraints forced these firms for foreign currency loans. Design/methodology/approach The study analysed data from 1,412 firms listed on the Bombay Stock Exchange in the manufacturing sector, covering the period from 1991 to 2022. A random effects probit model was used to examine the role of credit constraints on FCB, incorporating the influence of micro, small and medium enterprises (MSMEs) status and export activities. Additionally, a two-step system-generalized method of moment was used for robustness checks. Findings Export activities significantly influence FCB, with exporting firms showing a higher propensity to borrow foreign currency compared to domestically operating firms because of the increased funding needs of export activities. Larger firms are more likely to secure FCB than MSMEs, benefiting from collateral advantages. MSME exporting firms exhibit a higher tendency to borrow in foreign currency compared to large exporting firms. Research limitations/implications This study focuses on firm-level data and considers only demand-side credit constraints. It does not examine supply-side credit constraints affecting FCB. Social implications This study underscores the credit constraints faced by MSME exporters in the domestic market, leading them to rely on FCB. These insights are valuable for policymakers aiming to reduce MSMEs' dependency on FCB and enhance their export performance. Originality/value The findings highlight that MSME exporting firms are more inclined to borrow in foreign currency than their larger counterparts. This tendency is driven by the credit constraints MSMEs face because of asymmetric information and underdeveloped financial markets, which compel them to seek FCB.

TROPICAL PALMS AND FACTORS INFLUENCING THEIR DISTRIBUTIONS AND DIVERSITY, WITH A FOCUS ON Pinanga DIVERSITY IN SOUTHEAST ASIA

ARTICLE HIGLIGHTS- The palm genus Pinanga is the most diverse in Southeast Asia. - Limited ecological studies on Pinanga show the influence of environmental factors.- High Pinanga endemism in Borneo requires conservation action.ABSTRACTPalms represent some of the keystone species in tropical forests, providing numerous ecosystem services. They are widely studied by botanists because of their iconic and majestic appearance, although ecological studies of palm abundance, distributions, and diversity have only recently begun to gain attention. The abundance and diversity of palms at different spatial scales can be influenced by various factors, such as climate, soil properties, hydrology, topography and forest structure; understanding these influences is essential for conservation. This review details four abiotic factors (climate, soil chemistry, hydrology and topography) and one biotic factor (forest structure) affecting palm distribution and diversity. The genus Pinanga, one of the most diverse genera of palms, is discussed in terms of its distribution and diversity in Southeast Asia. Ecological studies on Pinanga diversity in the region are examined, revealing the influence of micro- and macro-scale variation in environmental factors, such as litter depth and thickness, canopy openness and crown cover, elevation, slope, aspect, light intensity, humidity and air temperature. The existing knowledge gaps on Pinanga ecology in Southeast Asia are discussed, and the need for more studies on population structures, functional traits and determinants of Pinanga diversity and distributions within different lowland forest types in the region are highlighted. The high endemism shown by Pinanga necessitates a more comprehensive ecological understanding of this genus to better inform its conservation and protection.

MSMEs and Rural Prosperity: A Study of their Influence in Indonesian Agriculture and Rural Economy

This research delves into the influence of Micro, Small and Medium Enterprises (MSMEs) on the progression of agriculture and the rural economy in Indonesia. MSMEs hold a pivotal position in the Indonesian economy, significantly contributing to job creation and economic expansion. Despite this, their potential to stimulate agricultural growth and enhance the rural economy remains largely uncharted. The investigation of this study centers on the mutual relationship between MSMEs and the agricultural sector. It emphasizes how MSMEs can instigate innovation, augment productivity, and pave the way for rural farmers to access markets. The study also scrutinizes the part MSMEs play in rural development by evaluating their role in boosting income, mitigating poverty, and empowering socio-economic aspects in rural regions. Furthermore, this study identifies the obstacles MSMEs encounter in their contribution to agricultural and rural economic development. These challenges include access to finance, technology, and a complex workforce. The report puts forth policy recommendations to surmount these hurdles and tap into the potential of MSMEs for the advancement of agriculture and rural economic growth in Indonesia. The study enriches the literature on MSMEs, agricultural development, and rural economics. It offers valuable insights for policymakers, practitioners, and researchers who are keen on promoting sustainable development in Indonesia. The findings of this research underscore the necessity of fortifying MSMEs to attain agricultural development and rural economic prosperity in Indonesia.

Recurrent double-conditional factor model

AbstractIn economic applications, the behavior of objects (e.g., individuals, firms, or households) is often modeled as a function of microeconomic and/or macroeconomic conditions. While macroeconomic conditions are common to all objects and change only over time, microeconomic conditions are object-specific and thus vary both among objects and through time. The simultaneous modeling of microeconomic and macroeconomic conditions has proven to be extremely difficult for these applications due to the mismatch of dimensions, potential interactions, and the high number of parameters to estimate. By marrying recurrent neural networks with conditional factor models, we propose a new white-box machine learning method, the recurrent double-conditional factor model (RDCFM), which allows for the modeling of the simultaneous and combined influence of micro- and macroeconomic conditions while being parsimoniously parameterized. Due to the low degree of parameterization, the RDCFM generalizes well and estimation remains feasible even if the time-series and the cross-section are large. We demonstrate the suitability of our method using an application from the financial economics literature.

Effects of polypropylene micro(nano)plastics on soil bacterial and fungal community assembly in saline-alkaline wetlands

Microplastic pollution is a major environmental threat, especially to terrestrial ecosystems. To better understand the effects of microplastics on soil microbiota, the influence of micro- to nano-scale polypropylene plastics was investigated on microbial community diversity, functionality, co-occurrence, assembly, and their interaction with soil-plant using high-throughput sequencing approaches and multivariate analyses. The results showed that polypropylene micro/nano-plastics mainly reduced bacterial diversity, not fungal, and that plastic size had a stronger effect than concentration on the assembly of microbial communities. Nano-plastics decreased the complexity and connectivity of both bacterial and fungal networks compared to micro-plastics. Moreover, bacteria were more sensitive and deterministic to polypropylene micro/nano-plastic stress than fungi, as shown by their different growth rates, guanine-cytosine content, and cell structure. Interestingly, the dominant ecological process for bacteria shifted from stochastic drift to deterministic selection with polypropylene micro/nano-plastic exposure. Furthermore, nano-plastics directly or indirectly disrupted the interactions within intra-microbes and between soil-bacteria-plant by altering soil nutrients and stoichiometry (C:N:P) or plant diversity. Collectively, the results indicate that polypropylene nano-plastics pose more ecological risks to soil microbes and their plant-soil interactions. This study sheds light on the potential ecological consequences of polypropylene micro/nano-plastic pollution in terrestrial ecosystems.

Influence of micro and nanoporous TiO2 surface modifications on physical-chemical and biological interactions

Titanium is widely used in implants but can cause adverse reactions like inflammation and tissue rejection. Surface modifications like acid-etching and anodization improve implant properties and osseointegration. This study investigated how micro and nanoporous TiO2 films affect the implant-host interaction, focusing on physical–chemical and biological aspects. Surface treated implants were obtained by acid-etched and anodization of commercially pure titanium (CPTi). Samples were characterized by FE- and FIB-SEM, XRD, EDX, WCA, profilometry, and electrochemical behavior was also investigated. Biocompatibility was accessed by protein adsorption (albumin and serum proteins), hemolysis, and in vitro fibroblast interaction. Anodic samples exhibited the highest corrosion resistance and apatite deposition. Protein adsorption was related to surface roughness and wettability. Samples followed the Langmuir model isotherm (Type I), except for galvanostatic samples (Type III isotherm). Kinetic adsorption was modeled by a pseudo-first-order model, wherein rate-limiting step is albumin diffusion into pores. All surfaces met the hemocompatibility requirements for its use as biomaterial (hemolysis index < 2 %). The upper surface roughness threshold was identified at approximately Sa ≈ 1 µm for better fibroblast viability, adhesion, and proliferation. Combining the results, nanoporous samples present optimized surface conditions that enhance body-fluid contact and improve cell adhesion, thereby contributing to long-term stability.

Influence of micro and nanofibrillated cellulose on sweetened yogurt production and storage

We assessed the impact of three hydrocolloids on the physicochemical properties of yogurt during production and storage. The hydrocolloids-microfibrillated, nanofibrillated, and post-treated nanofibrillated–were derived from vegetable cellulose and varied in their processing. We analyzed parameters including acidity, pH, syneresis, consistency, and particle size distribution, and performed scanning electron microscopy at 1, 15, 30, and 60 days post-production. Hydrocolloid incorporation significantly improved yogurt consistency and reduced syneresis; for instance, after 15 days, hydrocolloid-enriched yogurts exhibited only 1.05–1.19% syneresis compared with 2.77% in the control. Scanning electron microscopy and rheological assessments confirmed the role of nanofibers in protein network formation. However, pH and acidity remained unchanged.

Polyethylene terephthalate (PET) micro- and nanoplastic particles affect the mitochondrial efficiency of human brain vascular pericytes without inducing oxidative stress

The objective of this investigation was to evaluate the influence of micro- and nanoplastic particles composed of polyethylene terephthalate (PET), a significant contributor to plastic pollution, on human brain vascular pericytes. Specifically, we delved into their impact on mitochondrial functionality, oxidative stress, and the expression of genes associated with oxidative stress, ferroptosis and mitochondrial functions. Our findings demonstrate that the exposure of a monoculture of human brain vascular pericytes to PET particles in vitro at a concentration of 50 μg/ml for a duration of 3, 6 and 10 days did not elicit oxidative stress. Notably, we observed a reduction in various aspects of mitochondrial respiration, including maximal respiration, spare respiratory capacity, and ATP production in pericytes subjected to PET particles for 3 days, with a mitochondrial function recovery at 6 and 10 days. Furthermore, there were no statistically significant alterations in mitochondrial DNA copy number, or in the expression of genes linked to oxidative stress and ferroptosis, but an increase of the expression of the gene mitochondrial transcription factor A (TFAM) was noted at 3 days exposure.These outcomes suggest that, at a concentration of 50 μg/ml, PET particles do not induce oxidative stress in human brain vascular pericytes. Instead, at 3 days exposure, PET exposure impairs mitochondrial functions, but this is recovered at 6-day exposure. This seems to indicate a potential mitochondrial hormesis response (mitohormesis) is incited, involving the gene TFAM. Further investigations are warranted to explore the stages of mitohormesis and the potential consequences of plastics on the integrity of the blood-brain barrier and intercellular interactions. This research contributes to our comprehension of the potential repercussions of nanoplastic pollution on human health and underscores the imperative need for ongoing examinations into the exposure to plastic particles.

Disentangling the self-diffusional dynamics of H2 adsorbed in micro- and mesoporous carbide-derived carbon by wide temporal range quasi-elastic neutron scattering

Understanding the processes guiding the confinement of adsorbed H2 in different porous structures is vital for the development of adsorbents for effective cryo-adsorptive H2 storage systems. Quasi-elastic neutron scattering (QENS) is applied over a wide range of timescales (0.2 ps – 150 ps) to determine different self-diffusion mechanisms of H2 adsorbed in a carbide (synthesized from TiC via the sol-gel method) derived carbon (sol-gel TiC-CDC) adsorbent with hierarchical porous structure. The bulk and porous structure is characterized by gas adsorption, Raman spectroscopy, and wide-angle X-ray scattering methods. Sol-gel TiC-CDC belongs to a series of CDCs that have been previously characterized and where the self-diffusion of adsorbed H2 has been investigated with QENS. Sol-gel TiC-CDC is very mesoporous, has relatively high stacking (2.76 graphenic layers per stack), and small interlayer spacing of graphenic sheets (3.43 Å) in comparison to other CDCs in the series, thus, being a well-ordered highly porous CDC. Restricted rotational self-diffusion of adsorbed H2 is determined in ultramicropores (pore width, w, < 7 Å) and translationally self-diffusing H2 adsorbed in multilayers across multiple timescales are determined in micro- and mesopores (7 Å < w < 500 Å). The microporous and graphenic structure of the CDC does not remarkably affect the self-diffusion of H2 at high surface coverages. The simultaneous determination of adsorbed H2 motions across different timescales allows to analyze the influence of micro- and mesopores under H2 loading conditions, which are close to the ones used in technical applications and are vital for adsorbent optimization.

Study of the influence of micro- and nano-cellulose on the growth and carbonation kinetics of portlandite crystals

Restoration of historical buildings contributes to the preservation of history and identity of the cities, but also, in the current climate crisis, an alternative solution to reduce the environmental impact of the construction sector, which is one of the main global contributors to green-house gas emissions and waste production. It can be also claimed that the most sustainable building is the one that has already been built. An important aspect to consider for the restoration of built heritage is the use of compatible materials, such as lime-based mortars, that should be preferred over cement. However, their slow setting and hardening (via carbonation), and, in some cases, poor durability prevent their full acceptance and widespread use. One course of action is to improve the quality of the binder via an innovative approach: inclusion of natural organic additives during the slaking process of CaO. This is expected to have a higher impact than their inclusion in the mortar’s mix design. In the present work the analysis of the growth of Ca(OH)2 crystals following their crystallization in the presence of micro- and nano-cellulose is studied, together with the morphological changes that these additives induce on portlandite crystals. Moreover, the study of the carbonation kinetics of the modified portlandite crystals gives insights on the effect that these additives have on the quality of the binder. The promising results highlight the potential of micro- and nano-cellulose as sustainable additives for lime-based binders. Furthermore, these additives can be obtained from industrial wastes, promoting a circular economy.

Raman Gain in Transparent Nanostructured Glass-Ceramic

Stimulated Raman scattering in transparent glass-ceramics (TGCs) based on bulk nucleating phase Ba2NaNb5O15 were investigated with the aim to explore the influence of micro- and nanoscale structural transformations on Raman gain. TGCs are composed of nanocrystals that are 10–15 nm in size, uniformly distributed in the residual glass matrix. A significant Raman gain improvement for both BaNaNS glass and TGCs with respect to SiO2 glass is demonstrated, which can be clearly related to the nanostructuring process.

Experimental investigation of the mutual influence of micro- and macroscale processes on the displacement of viscous oil by water in a two-layer porous medium

This paper presents the results of an experimental and theoretical study of the immissible displacement of high-viscosity model oil from the two-layer porous medium with different layers permeability. The experiments were performed using cylindrical model of the porous medium having the ratio of transverse size to length D/L equals to 0.05 and ratio of layers permeability equals to 0.46 during forced imbibition and drainage. It is shown that the alignment of a displacement front in the layers is caused by macroscale capillarity-driven flow arising from the curvature of the front. The conditions for stabilized motion of the displacement front for this case are determined using the analytical model and proved using experimental data on the recovery of displaced fluid. Microscale processes in pore level caused by the influence of the capillary forces are taken into account throw the relative phase permeability and capillary pressure curves.

The influence of micro-/macro-structure of a boron-doped diamond electrode on the degradation of azo dye Direct Red 80

The influence of micro-/macro-structure of a boron-doped diamond electrode on the degradation of azo dye Direct Red 80

Numerical Modeling of Shale Oil Considering the Influence of Micro- and Nanoscale Pore Structures

A shale reservoir is a complex system with lots of nanoscale pore throat structures and variable permeability. Even though shale reservoirs contain both organic and inorganic matter, the slip effect and phase behavior complicate the two-phase flow mechanism. As a result, understanding how microscale effects occur is critical to effectively developing shale reservoirs. In order to explain the experimental phenomena that are difficult to describe using classical two-phase flow theory, this paper proposes a new simulation method for two-phase shale oil reservoirs that takes into account the microscale effects, including the phase change properties of oil and gas in shale micro- and nanopores, as well as the processes of dissolved gas escape, nucleation, growth and aggregation. The presented numerical simulation framework, aimed at comprehending the dynamics of the two-phase flow within fractured horizontal wells situated in macroscale shale reservoirs, is subjected to validation against real-world field data. This endeavor serves the purpose of enhancing the theoretical foundation for predicting the production capacity of fractured horizontal wells within shale reservoirs. The impact of capillary forces on the fluid dynamics of shale oil within micro- and nanoscale pores is investigated in this study. The investigation reveals that capillary action within these micro- and nanoscale pores of shale formations results in a reduction in the actual bubble point pressure within the oil and gas system. Consequently, the reservoir fluid persists in a liquid monophasic state, implying a constrained mobility and diminished flow efficiency of shale oil within the reservoir. This constrained mobility is further characterized by a limited spatial extent of pressure perturbation and a decelerated pressure decline rate, which are concurrently associated with a relatively elevated oil saturation level.

Simulation of slotting conditions on irrigated lands in the south of Russia under increasing climate change

The article considers the results of numerical studies on the improvement of existing tillage tools, namely, the improvement of the technical parameters of the furrower, which will improve the water-physical properties of irrigated lands in southern Russia with increasing climate change. Every year, the areas of irrigated land are reduced as they are exposed to natural (for example, rains; floods; surface runoff; diversity of soil cover, the influence of micro- and macrorelief) and anthropogenic (for example, non-compliance with irrigation norms, crop rotation composition, soil cultivation rules; introducing incorrect doses of fertilizers; exclusion of technological operations in order to save resources) factors. In this regard, the solution to the problem of preserving the agro-resource potential of the lands is relevant, and its solution guarantees the food security of Russia. Numerical modeling of dangerous loadings of the technical parameters of the slotter-furrower has been carried out, the types and types of equipment have been selected, their parameters have been calculated, as well as the organization and technology of tillage processes.

Influence of micro– and macrostructure when determining the contact resistivity of interconnects based on electrically conductive adhesives

The contact resistivity of interfaces in solar module interconnects has a direct impact on the series resistance of the entire module and fill factor. Thus, this impacts the performance of entire photovoltaic systems. Accurate measurement of the contact resistance is a key component of optimizing the performance of such interconnects. However, this is difficult for electrically conductive adhesive (ECA) based interconnects. This work shows that transmission line method (TLM) test structures based on ECA display non–negligible inhomogeneities leading to inaccuracies when determining the contact resistivity. Seven methods based on two models — the front– and end–contact TLM models (or a combination of both) — were investigated for four commercially available ECAs used in solar modules and their impacts on the extrapolation of the contact resistivity were quantified. It was determined that even when macroscale inhomogeneities (e.g., variations in the thickness of the ECA) are not present, microscopic structural effects influence the sheet and contact resistance. In particular, variations in the distribution of fillers significantly alter the bulk resistivity of the composites and this variability is also clearly correlated with differences in the geometry of the fillers. It is concluded that the best approach to reduce inaccuracies in the determination of the contact resistivity of ECA–based interconnects is to calculate the sheet and contact resistance locally (using three consecutive contacts) employing a redundant and modified test structure. Afterwards, the contact resistivity ought to be computed using the end–contact TLM model and the median should be assigned as the contact resistivity of the sample.

Determinants of Factors Affecting the Financial Performance of Indian General Insurance Firm: Panel Data Evidence

The researchers aim to examine the firm-specific variables that impact the financial performance of general insurance firms in India. The study’s scope is limited to India’s insurance industries from 2010-2011 to 2019-2020. The research considers 21 insurance firms in India out of 35 general insurers. We obtain statistical data from the financial statements of insurance companies. The research used correlation analysis and panel data regression to evaluate financial performance and its impacts. Panel data techniques were employed in the analysis to study the impact of eleven micro factors on the monetary performance of general insurers in India. The influence of micro (internal) variables such as capital adequacy ratio, firm size, age of the firm, retention, liquidity, loss ratio, investment ratio, reinsurance dependence, financial leverage, tangibility, and premium growth rate on the financial performance has been determined using econometric findings in this research. The fixed-effect model results reveal that firm’s age, loss ratio, size, premium growth, and retention ratio are vital in affecting the financial performance of Indian general insurance firms. On the other hand, liquidity and financial leverage are insignificant in determining the financial performance of general insurance firms in India.