Effect of Urea on the Mechanical Properties of Gelatin Films Photocured with 2-Ethylhexyl Acrylate

Thin films of gelatin were prepared by casting. Then the films were photocured and the mechanical properties were studied. The tensile strength of UV cured gelatin films showed about 10% enhancement than that of raw gelatin films. Minor amount of urea (1–5%) was used as additive in aqueous gelatin solution and films were prepared using same technique. Four formulations were prepared in methanol with 2-ethylhexyl acrylate in the presence of photoinitiator (darocur-1664). The films were soaked in the prepared formulations and then cured under UV radiation at different intensities (5–25 passes). Percentage of urea, monomer concentration, soaking time and radiation intensities were optimized with the extent of polymer loading, TS and elongation at break of the photocured film. The films containing 2% urea, cured with 3% EHA for 3 min at 15th UV pass showed the highest mechanical properties. A significant improvement of TS (31%) occurred when EHA (3%) was incorporated.     

Biodegradation of pretreated polyethylene film by Pseudomonas aeruginosa AMB-CD-1

A comparative study evaluated the acid, alkali, and heat-treated polyethylene biodegradation efficiency of Pseudomonas aeruginosa AMB-CD-1. The polyethylene (PE) pieces were separately treated with heat (50°C), acid (1N HCl), and alkali (1N NaOH) and then washed with water before use. All the treated samples were analyzed through thermogravimetric analysis. In addition, weight and temperature changes during the decomposition reactions were also measured and determined. In these treatments, the PE films of heat-treated and acid-treated low-density polyethylene (LDPE) indicated more significant weight loss at 120°C (48.99% and 40.75%, respectively) as compared to their control or untreated PE and alkali-treated LDPE (21.84% and 24.68%, respectively). A biodegradation assay was then conducted with treated and untreated LDPE films with P. aeruginosa AMB-CD-1 strain. Fourier transform infrared spectroscopy analysis revealed that the heat or acid-pretreated samples with isolate AMB-CD-1 displayed peaks at 2922.84, 2923.97, and 1450.31, 874.22 cm⁻¹ for C–H stretching deformation vibration, CH₂ scissoring vibration, –CHO stretching, and strong alkyl structure, respectively. Furthermore, the new peaks with a significant difference at 2500–2000 cm⁻¹ (O═C═O, O–H stretching vibration: carboxylic acid) and 1500–1000 cm⁻¹ (–CHO and C═O stretching) were noticed in the infrared spectral range of LDPE degradation. Modifications in the functional group provided evidence that biodegradation had impacted the chemical structure of the LDPE film. Additionally, it was demonstrated that pretreating LDPE films with heat or acid could speed up their biodegradation.     

Markov regression model for analyzing big data to predict trajectories of repeated categorical outcomes: an application to $$hbox {PM}_{2.5}$$ PM 2.5 air pollution data

Environmental and Ecological Statistics - Fine particulate matter ( $$text{ PM}_{2.5}$$ ), tiny particles in the air, is air contamination that negatively impacts the environment and human health...     

Development of novel absorbents for CO2 capture from blast furnace gas

In order to establish energy-saving technology for CO₂ capture from blast furnace gas, novel absorbents were developed in the laboratory and evaluated at a 1 t_CO2/d test plant. At first, CO₂ absorption and desorption behaviors of single-component amine solvents for simulated blast furnace gas (CO₂/N₂ = 20%/80%) were investigated through a screening test using a small scrubbing bottle. These amine solvents were additionally analyzed using nuclear magnetic resonance (¹³C NMR) spectroscopy and reaction calorimetry. The results of the laboratory experiments showed that there was a trade-off between absorption rate and enthalpy of absorption but some absorbents had unique features. For example, 2-isopropylaminoethanol (IPAE) had high absorption rate and small enthalpy of absorption. Then, new IPAE-based amine solvents (RITE solvents: RITE-A and RITE-B) were formulated and evaluated at the 1 t_CO2/d test plant. CO₂ regeneration energies of the RITE solvents were 3.3 and 3.1 GJ/t_CO2, respectively. With certain process conditions and plant specifications optimized, RITE-B was estimated to have the potential to achieve 2.5 GJ/t_CO2.     

Uncertainty characterization approaches for risk assessment of DBPs in drinking water: A review

The management of risk from disinfection by-products (DBPs) in drinking water has become a critical issue over the last three decades. The areas of concern for risk management studies include (i) human health risk from DBPs, (ii) disinfection performance, (iii) technical feasibility (maintenance, management and operation) of treatment and disinfection approaches, and (iv) cost. Human health risk assessment is typically considered to be the most important phase of the risk-based decision-making or risk management studies. The factors associated with health risk assessment and other attributes are generally prone to considerable uncertainty. Probabilistic and non-probabilistic approaches have both been employed to characterize uncertainties associated with risk assessment. The probabilistic approaches include sampling-based methods (typically Monte Carlo simulation and stratified sampling) and asymptotic (approximate) reliability analysis (first- and second-order reliability methods). Non-probabilistic approaches include interval analysis, fuzzy set theory and possibility theory. However, it is generally accepted that no single method is suitable for the entire spectrum of problems encountered in uncertainty analyses for risk assessment. Each method has its own set of advantages and limitations. In this paper, the feasibility and limitations of different uncertainty analysis approaches are outlined for risk management studies of drinking water supply systems. The findings assist in the selection of suitable approaches for uncertainty analysis in risk management studies associated with DBPs and human health risk.     

Growth of non-English-language literature on biodiversity conservation

English is widely recognized as the language of science, and English-language publications (ELPs) are rapidly increasing. It is often assumed that the number of non-ELPs is decreasing. This assumption contributes to the underuse of non-ELPs in conservation science, practice, and policy, especially at the international level. However, the number of conservation articles published in different languages is poorly documented. Using local and international search systems, we searched for scientific articles on biodiversity conservation published from 1980 to 2018 in English and 15 non-English languages. We compared the growth rate in publications across languages. In 12 of the 15 non-English languages, published conservation articles significantly increased every year over the past 39 years, at a rate similar to English-language articles. The other three languages showed contrasting results, depending on the search system. Since the 1990s, conservation science articles in most languages increased exponentially. The variation in the number of non-English-language articles identified among the search systems differed markedly (e.g., for simplified Chinese, 11,148 articles returned with local search system and 803 with Scopus). Google Scholar and local literature search systems returned the most articles for 11 and 4 non-English languages, respectively. However, the proportion of peer-reviewed conservation articles published in non-English languages was highest in Scopus, followed by Web of Science and local search systems, and lowest in Google Scholar. About 20% of the sampled non-English-language articles provided no title or abstract in English; thus, in theory, they were undiscoverable with English keywords. Possible reasons for this include language barriers and the need to disseminate research in countries where English is not widely spoken. Given the known biases in statistical methods and study characteristics between English- and non-English-language studies, non-English-language articles will continue to play an important role in improving the understanding of biodiversity and its conservation.     

Multifaceted role of natural sources for COVID-19 pandemic as marine drugs

Environmental Science and Pollution Research - COVID-19, which is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has quickly spread over the world, posing a...