Indoor air pollution from biomass fuel combustion remains a major environmental and public health concern in rural communities of developing countries. This study aimed to investigate indoor particulate matter concentrations, particle size distribution, variation during cooking, age-dependent respiratory deposition and inhalation dose in households using firewood and liquefied petroleum gas (LPG) among four indigenous Naga communities: Mao, Maram, Poumai, and Zeliangrong. Real-time 24h monitoring of PM10, PM2.5, and PM1 concentrations were done using GRIMM Aerosol Spectrometer (Model 1.09) for three separate days for each household, resulting to 60 monitoring days, including 48 firewood-using households and 12 LPG-using households recording 93 cooking events in firewood and 24 in LPG-using households. Respiratory deposition fractions and inhalation doses across different age groups were estimated using the Multiple-Path Particle Dosimetry (MPPD) model. Findings revealed that firewood-using households recorded consistently higher concentrations than LPG, where the 24h mean for PM10 was 79.34 ± 42.11 μg/m3, PM2.5 (47.08 ± 25.5 μg/m3), and PM1 was 42.28 ± 23.56 μg/m3. Peak PM10 concentration exceeds several thousand μg/m3 during cooking events indicating intense short-duration pollution episode. Variation in particulate matter concentrations were recorded among the communities’ reflecting household characteristics, stove design, cooking practices, ventilation conditions, and neighbourhood smoke exposure. Particle number concentrations were dominated by fine and submicron particles (<1 μm), suggesting combustion processes were the primary emission source. Deposition model indicated that inhalable particles represented the largest fraction of respiratory dose, while fine particles exhibited pulmonary deposition. Estimated inhalation dosage increased with age due to higher breathing rates and lung capacity. The findings underscore significant exposure and health risks associated with biomass-based cooking and emphasis the need for targeted interventions to improve public health outcomes among understudied indigenous communities.
Let q be a prime power and m > 1 be any integer. Let F-q(m) be the finite field of order q(m) and theta is an element of F-q(m) be such that F-q(m) = F-q(theta). We obtain a nontrivial bound for the mixed character sum Sigma(x is an element of Fq)chi(theta + x) psi(x), where chi and psi are multiplicative and additive characters of F-q(m) and F-q, respectively, using function field methods. As an application of our main result, we prove that for fixed m and sufficiently large prime powers q, that satisfy certain conditions, F-q(m) /F-q possesses the weak line property for primitive normal elements. In particular, our result is a strengthening of existing results. (c) 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
A transition metal-free binary composite of sulfur nanoparticle (SNPs) and nano silica (SiO2), designated as S-SiO2 was deliberately engineered via a hydrothermal method. SiO2 nanoparticles were synthesized from this residual rice husk using a simple and cost-effective procedure. The observed colour change from orange to pale yellow, along with the appearance of a UV absorption peak at 215 nm after 125 h, confirms the formation of sulfur nano particles. The assembled material was comprehensively characterized by different spectroscopic techniques. The synthesized S-SiO2 nanoconjugate have been examined as a potent photocatalyst for Tetracycline Hydrochloride (TCH) degradation from wastewater in presence of oxone under UV-light exposure. The synergistic combination of the transition metal-free S-SiO2 nanocomposite and oxone significantly boosted the formation of reactive oxidative species like sulfate (SO4-center dot) radicals. Under UV-light, similar to 95.96% of TCH degradation was achieved within 60 min. The intermediates were analyzed through Mass Spectrometric analysis. The catalyst remained stable over acidic, neutral, and basic pH conditions, retaining high activity. Furthermore, the photocatalyst displayed good recyclability upto 5th catalytic cycle with negligible loss in activity.
The current study emphasizes understanding the impact of impurities on the electrocatalytic efficiency of nickel oxide (NiO) for the methanol oxidation reaction (MOR) in 1 M KOH. It was evident that NiO with p-block elements, like boron (B) and sulfur (S), showed remarkable MOR activity with a low onset potential and better kinetic profile. NiO having both B and S exhibited MOR at a very low onset potential of 1.38 V vs RHE and a reduced Tafel slope of 42 mV dec-1. However, NiO having either B or S as an impurity showed onset potentials of 1.41 and 1.33 V vs RHE with higher Tafel slope values of 106 and 133 mV dec-1, respectively. The significant MOR activity of NiO with a low content of S and a slightly higher content of B was attributed to the change in the electronic structure with the reformation of the Fermi levels as evident from the density of states (DOS) and projected density of states (PDOS) calculations. Doping with B and S lowered the Fermi level of NiO from 2.196 to 2.070 eV. The doped NiO material also showed high stability and durability in an alkaline medium and retained the electrochemical activity for up to 12 h. The overall MOR process was investigated through FTIR and Raman studies. From the spectroscopic analyses, it was confirmed that the MOR proceeded via the formation of intermediates such as formate and carbonate.
With evolving market demands, there is a critical need to transcend beyond conventional petroleum-based packaging strategies, as their extensive use has led to serious environment-related issues. In response, a new generation of intelligent packaging systems has been developed to enable continuous monitoring of packaged foods and to provide real-time information on their quality and safety status. Within this context, in the present study, multifunctional freshness indicator films of pectin and pullulan were fabricated, wherein anthocyanin rich hibiscus extract (AHE) and tea tree oil loaded Pickering emulsions (PEs) were intricately incorporated into the biopolymeric pectin/pullulan matrix. Furthermore, the developed films were analyzed for their structural, physicochemical, barrier, optical, color stability, ammonia vapor sensitivity and antioxidant activities. X-ray diffraction of the films showed a wide peak at 21.47 degrees (2 theta), suggesting specific structural characteristics. Physicochemical analysis showed an increase in thickness (0.17 +/- 0.015-0.49 +/- 0.015 mm), followed by decrease in moisture content (22.78 +/- 0.42% to 15.40 +/- 0.28%) and water absorption (60.71 +/- 0.50% to 24.62 +/- 0.34%). The pectin/pullulan/PE/AHE film exhibited a tensile strength of 8.43 +/- 0.48 MPa and an elongation at break of 69.50 +/- 3.14%, along with the highest antioxidant activity (43.52 +/- 0.23%). When tested for ammonia vapor sensitivity, the films showed significant color change (Delta E > 53), indicating their potential for real time freshness monitoring quality. Furthermore, the indicator films were also evaluated for the real time freshness of chicken meat. In general, this study provides valuable insights in formulating composite films with anthocyanin and PE, contributing to multifunctional packaging systems with enhanced functionality and greater utility in the food business.
