Mixture Samples Research Articles

Rapid UV-Vis spectrophotometric method aided by firefly-PLS models for the simultaneous quantification of ciprofloxacin, lomefloxacin, and enrofloxacin in their laboratory mixture, dosage forms and water samples: greenness and blueness assessment

Herein, a novel UV spectrophotometric method coupled with chemometric tools was developed for the simultaneous determination of three fluoroquinolone antibiotics: ciprofloxacin, lomefloxacin, and enrofloxacin. Such integration of UV spectroscopy and chemometric analysis proved to be a simple, rapid, and cost-effective approach for the quantification of these clinically important pharmaceutical compounds and aid in their quality control analysis. The method employed firefly algorithm for variable selection and partial least squares (PLS) regression for model calibration. The developed method was validated by independent test set in addition the accuracy, intra and inter-day precision as per ICH guidelines which showed a satisfactory performance with mean recovery ranged between 98.18 and 101.83 with %RSD < 2. Besides, the developed method displayed ultrasensitive levels with LODs (0.0803, 0.1125, 0.1309 µg/mL) and LOQs (0.2434, 0.3409, 0.3968 µg/mL) for ciprofloxacin, lomefloxacin, and enrofloxacin, respectively. The greenness and blueness of the developed method were also evaluated using the recently proposed Analytical GREEnness metric approach (AGREE) and Blue applicability grade index (BAGI) tools, which showed a high AGREE score of 0.79 and a BAGI score of 77.5. These results indicate that the developed method provides an environmentally friendly alternative to the traditionally used chromatographic techniques, while maintaining high analytical practicability. Finally, the application of the developed methodology was demonstrated on real pharmaceutical and tap water samples, and the results were in good agreement with those obtained by the reference HPLC method indicating the reliability and suitability of the proposed spectrophotometric method for routine analysis of fluoroquinolone antibiotics.

Assessment of bacterial and fungal contamination of herbal mixture vended within Kaduna metropolis, Nigeria

The consumption of herbal mixtures among Nigerians have been on the increase in recent years. Many herbal mixtures sold to the general public are likely to be contaminated by a diverse range of potentially pathogenic microorganisms due to lack of good manufacturing practices (GMPs). Therefore, this study is aimed to evaluate the bacterial and fungal profile of herbal mixtures sold within the Kaduna metropolis. A total of twenty samples of herbal mixtures were randomly purchased fromfour distinct locations within the Kaduna metropolis. The samples were subjected to microbiological analysis using standard methods. Bacterial genera isolated from the herbal mixture samples include Bacillus sp., Staphylococcus sp., Streptococcus sp. while the fungal genera were Aspergillus sp., Saccharomyces sp., Fusarium sp. and Penicillium sp. Herbal mixture obtained from Mandao and Malali district had the highest (9.68±1.70×105CFU/ml) and lowest (6.60±0.43×105CFU/ml) bacterial load while the corresponding fungal load involved samples obtained from Central market (1.48±11.25×104 CFU/ml) and Tudun Wada (1.48± 3.11 ×103 CFU/ml), respectively. Bacillus sp. (60%) and Aspergillus sp. (45%) were the dominant bacterial and fungal genera, respectively. Given the substantial microbial contamination of herbal mixtures and the potential pathogenicity of certain isolates, it is imperative to ensure that herbalists are wellinformed about the principles and implementation of GMPs. It is recommended that regular microbiological monitoring of herbal mixtures should be conducted.

Producing Biogas from Difference Mixing Ratio of Local Pig’s Waste to Produce the Methane Gas in Highest Volume

This research aimed to investigate the appropriate mixing ratio of local pig waste and water to produce biogas. The pigs were fed with a mixture of bran and boiled Colocasia. This research included four mixture samples in each 3 kg in different total solid (TS) mixing ratios as S1 (TS = 5%), S2 (TS = 6%), S3 (TS = 8%), and S4 (TS = 10%). The mixtures were mixed pig waste and water with ratios of 1:2.5, 1:2, 1:1.5, and 1:1. The total retention time was 60 days. The results showed the PH on average was 7.00-7.15. The appropriate retention time was day 30. The mixture that produced the highest CH4 were S3, S4, S2, and S1 in 68.5, 61, 37.4, and 23.5%VOL, for the H2S and CO2 results varied by the TS. The highest values of H2S at 1329, 1137, 45, and 21 ppm and the highest value of CO2 at 33.57%Vol, 30,68, 19,83, and 17,15 %VOL respectively.

Recognition and Characterization of Nanoscale Phases: Modulus Mapping of Asphalt Film in Pavement Mixture Cores.

The objective of this study is to recognize and characterize the nanoscale phase modulus mapping of the asphalt film in pavement mixture cores using atomic force microscopy quantitative nanomechanical technology. The pavement core samples from the upper and middle layers of four highways and laboratory samples were taken as the research object. The phase modulus-macro property correlation of recovered asphalt was analyzed using mathematical statistics. The results showed that the pavement core samples had more significant multi-phase and diversified phase characteristics compared to lab samples. This indicated that the asphalt in the pavement core had an obvious phase separation phenomenon due to aging. The phase modulus of each sample was distributed across a relatively wide numerical range, and there were also many numerical points with large fluctuations. Especially for the mixture sample containing SBS (Styrene-Butadiene-Styrene)-modified asphalt, the phase modulus distribution mappings presented a multi-peak phenomenon. Hence, considering the distribution characteristics of the data, the box plot method was introduced. Compared with quantified results from laboratory samples, the phase modulus of SBS-modified asphalt increased by 0.96 times, 1.18 times and 1.15 times, and that of base asphalt increased by 0.59 times, 0.56 times, 0.42 times, 1.24 times and 0.39 times, respectively. This indicates that the aging degree of asphalt in the upper layer was generally greater than that of the asphalt in the middle layer and that there was an aging gradient in the direction of pavement depth. All points were within the 95% confidence band in terms of correlation fitting, indicating a better fitting effect between phase modulus and complex shear modulus, as well as between phase modulus and penetration. This research provides innovative ideas for future multi-scale numerical simulation and cross-scale performance model development of asphalt binders.

Risk minimization using robust experimental or sampling designs and mixture of designs

For both experimental and sampling designs, the efficiency or balance of designs has been extensively studied. There are many ways to incorporate auxiliary information into designs. However, when we use balanced designs to decrease the variance due to an auxiliary variable, the variance may increase due to an effect which we define as lack of robustness. This robustness can be written as the largest eigenvalue of the variance operator of a sampling or experimental design. If this eigenvalue is large, then it might induce a large variance in the Horvitz–Thompson estimator of the total. We calculate or estimate the largest eigenvalue of the most common designs. We determine lower, upper bounds and approximations of this eigenvalue for different designs. Then, we compare these results with simulations that show the trade-off between efficiency and robustness. Those results can be used to determine the proper choice of designs for experiments such as clinical trials or surveys. We also propose a new and simple method for mixing two sampling designs, which allows to use a tuning parameter between two sampling designs. This method is then compared to the Gram–Schmidt walk design, which also governs the trade-off between robustness and efficiency. A set of simulation studies shows that our method of mixture gives similar results to the Gram–Schmidt walk design while having an interpretable variance matrix.

Study of the amino acid composition of Chimáphila umbelláta herb

The therapeutic use of amino acids is a promising direction of modern pharmacy and medicine. Amino acids play an important role in the complex pharmacological action of herbal medicines, and also improve the assimilation of other biologically active substances (BAS) and are able to potentiate their pharmacological activity. A sufficiently rich source of amino acids are medicinal plants that combine in their composition a complex of groups of BAS, thanks to which they have a combined effect on the body The purpose of the work was the study the amino acids of Chimáphila umbelláta herb with the aim of expanding the knowledge about the chemical composition of the herbal raw material and the development of a phytotherapeutic agent with nephroprotective and anti-inflammatory properties in the future. The object of the study was Chimáphila umbelláta dried herb (supplier «World of Herbs», Kharkiv). The research was performed by gas chromatography-mass spectrometry using a SHIMADZU GC-MS-QP2010 chromatographic system connected to an electron ionization ion source and a single-quadrupole MS 5975C (Shimadzu Technologies). A robotic autosampler and a split/non-split injection port were used. The separation of amino acids was carried out in an Rxi-5 ms (capillary column of Restek Corporation – length 30 m, outer diameter 0.25 mm and thickness liquid–stationary phase 0.25 μm) with a liquid stationary phase of 5% diphenyl and 95% polysiloxane, with helium at purity 99.99% as a carrier gas at a constant flow of 1.47 ml/min. Standard mixtures of L-amino acids: alanine, serine, valine, threonine, leucine, isoleucine, proline, aspartic acid, glutamic acid, lysine, methionine, phenylalanine, and tyrosine (Sigma-Aldrich GmbH, Steinheim, Germany) were used for the analysis. Amino acids were identified by comparing the mass spectra of compounds with data from the NIST14 and WRT10 libraries, and a mixture of standard samples was used to identify and quantify amino acids. The content of 7 amino acids, of which 3 are essential amino acids (L-valine, isoleucine, L-leucine) were identified in Chimáphila umbelláta herb. The largest amount contains L-glutamic acid (14.469 µg/g), the smallest – L-leucine (0.050 µg/g). The obtained results are important in the development of a phytotherapeutic agent for use in diseases of the kidneys and urinary tract. The amino acids identified in the studied raw materials play an important role, so L-glutamic acid participates in protein and carbohydrate metabolism, stimulates oxidation processes, helps detoxify and remove ammonia from the body, increases the body’s resistance to hypoxia. Alanine has the ability to reduce the risk of developing kidney stones, it is the basis of normal metabolism in the body, helps fight hypoglycemia; helps to moderate fluctuations in blood glucose levels between meals. The content of aspartic acid is also important – the precursor of lysine and the donor of amino groups in the biosynthesis of substitute amino acids. The quantitative content of amino acids in Chimáphila umbelláta herb was studied by the method of gas chromatography-mass spectroscopy. According to the results of the study, the content of amino acids was determined in the following order: L-glutamic acid &gt; L-alanine &gt; L-aspartic acid &gt; L-valine &gt; L-proline &gt; isoleucine &gt; L-leucine. The results of the conducted research indicate a rather high and diverse content of amino acids in Chimáphila umbelláta herb, which can improve the balance of phytoremedies and dietary supplements for the purpose of prevention of deficiency of this class of biologically active substances.

An innovative mixture sampling strategy with uniform design: Application to global sensitivity analysis of mixture toxicity

Global sensitivity analysis combined with quantitative high-throughput screening (GSA-qHTS) uses random starting points of the trajectories in mixture design, which may lead to potential contingency and a lack of representativeness. Moreover, a scenario in which all factor levels were at stimulatory effects was not considered, thereby hindering a comprehensive understanding of GSA-qHTS. Accordingly, this study innovatively introduced an optimised experimental design, uniform design (UD), to generate non-random and representative sample points with smaller uniformity deviation as starting points of multiple trajectories. By combining UD with the previously optimised one-factor-at-a-time (OAT) method, a novel mixture design method was developed (UD-OAT). The single toxicity tests showed that three pyridinium and five imidazolium ionic liquids (ILs) exerted stimulatory effects on Vibrio qinghaiensis sp.-Q67; thus, four stimulatory effective concentrations of each IL were selected as factor levels. The UD-OAT generated 108 mixture samples with equal frequency and without repetition. High-throughput microplate toxicity analysis revealed that all 108 mixtures exhibited inhibitory effects. Among these, type B mixtures exhibited increasing toxicities that subsequently decreased, unlike type C mixtures, which consistently increased over time. GSA successfully identified three of the eight ILs as important factors influencing the toxicities of the mixtures. When individual ILs produced stimulatory effects, mixtures containing two to three ILs exhibited either stimulatory effects or none. In contrast, mixtures containing five to eight ILs exhibited inhibitory effects, while those containing four ILs showed a transition from stimulatory to inhibitory effects. This study provides a novel mixture design method for studying mixture toxicity and fills the application gap of GSA-qHTS. The phenomenon of individuals being beneficial while mixtures can be harmful challenges traditional mixture risk assessments.

LAMAIS: A library-aided approach for efficient 1D 1H NMR qualitative analysis in plant metabolomics

BackgroundOne-dimensional proton nuclear magnetic resonance (1D 1H NMR) spectroscopy is a non-destructive, non-targeted analytical technique providing both qualitative and quantitative insights, particularly beneficial for mixture analysis. However, the qualitative analysis of 1D 1H NMR spectra for mixture samples is laborious and time-consuming, involving extensive database searches and verification experiments like spiking. This process heavily relies on the analyst's expertise, leading to efficiency discrepancies. There is a pressing need for a reliable method to streamline operations and enhance the efficiency of qualitative analysis in complex mixtures. ResultsWe introduce a library-aided method for spectral profiling, named LAMAIS. This method achieves compound identification through similarity assessment between samples and template data, allowing rapid, automatic compound identification and full-spectrum peak assignment without the need for fitting. LAMAIS correctly identifies over 90 % of components in synthetic mixtures and more than 75 % in experimental mixtures, surpassing other representative methods with a higher F2 score. Our reference library, which currently includes 71 compounds, is tailored to capture the commonality of primary metabolites across diverse plant species. The analysis of real-world samples yielded encouraging results, underscoring LAMAIS's versatility as an auxiliary tool suitable for a variety of botanical sources. For analyst convenience, interactive graphics are utilized as the output format. SignificanceLAMAIS excels, demonstrating competitiveness and reliability. The approach minimizes repetitive tasks and sample wastage, improving the efficiency of 1D 1H NMR qualitative analysis. Constructing a reference library effectively preserves knowledge, mitigates reliance on human experience, and addresses gaps in the analysis of plant source samples.

Rice sample preparation method for ICP-MS and CV-AFS analysis: Elemental levels and estimated intakes

Eight sample digestion procedures were compared to determine 41 elements in rice samples by ICP-MS and CV-AFS. Analytical methods were evaluated using certified rice flour reference material (NIST 1568b) and recovery experiments. The microwave-assisted digestion of 0.5 g rice sample and reagent mixture of 2 mL HNO3, 0.5 mL H2O2, and 0.5 mL deionized water yielded the best recovery for all elements ranging from 90 to 120% at three different levels, bias% within 10%, and precision (coefficient of variation percent, CV% intra- and inter-day) below 15%. The best analytical method was applied to the elemental determination in nine types of rice available on the Italian market. Daily or weekly rice consumption meets the nutritional and safety requirements of EFSA and WHO. The present study allows extensive and detailed knowledge of the content of essential and non-essential/toxic elements in different types of rice produced or packaged in Italy.

Assessment of emerging and persistent contaminants in an anthropogenic-impacted watershed: Application using targeted, non-targeted, and in vitro bioassay techniques

Emerging and persistent contaminants (EPC) pose a significant challenge to water quality monitoring efforts. Effect-based monitoring (EBM) techniques provide an efficient and systematic approach in water quality monitoring, but they tend to be resource intensive. In this study, we investigated the EPC distribution for various land uses using target analysis (TA) and non-target screening (NTS) and in vitro bioassays, both individually and integrated, in the upper Ping River Catchment, northern Thailand. Our findings of NTS showed that urban areas were the most contaminated of all land use types, although agriculture sites had high unexpected pollution levels. We evaluated the reliability of NTS data by comparing it to TA and observed varying inconsistencies likely due to matrix interferences and isobaric compound interferences. Integrating NTS with in vitro bioassays for a thorough analysis posed challenges, primary due to a scarcity of concentration data for key compounds, and potentially additive or non-additive effects of mixture samples that could not be accounted for. While EBM approaches place emphasis on toxic sites, this study demonstrated the importance of considering non-bioactive sites that contain toxic compounds with antagonistic effects that may go undetected by traditional monitoring approaches. The present work emphasizes the importance of improving NTS workflows and ensuring high-quality EBM analyses in future water quality monitoring programs.

Modified electrode configuration of the free-fall tribo-electrostatic separator for the recovery of polyethylene and polypropylene flakes from shredded packaging waste

Free-fall tribo-electrostatic separators have long been used for sorting granular plastic wastes. The aim of this paper is to propose a modified configuration of the electrode system of such a separator and validate its effectiveness for processing a mixture of polyethylene (PE) and polypropylene (PP) flakes originating from the processing of packaging waste at GRANUPLAST Company, Jassans-Riottier, France. The mixture to be treated is not homogeneous and consisted of roughly 2/3 PE and 1/3 PP. The granular mixture samples were charged by triboelectric effect in a fluidized bed device, and then introduced into a laboratory-scale free-fall electrostatic separator. Preliminary tests were conducted to ascertain the mass of the mixture to be introduced in the fluidized bed and the duration of the charging process. Better results were obtained with the modified electrode configuration of the free-fall electrostatic separator. Thus, from 100 g of mixed flakes, 98.2% of PE and 96.6% of PP were recovered with purities of 99.1% and 98%, respectively. In addition, numerical modeling of the PP and PE particles trajectory was performed to simulate the behavior of charged particles in the standard and modified electrode configurations. Work is in progress for the industrial implementation of this tribo- electrostatic separation technology.

Blending Samples to Increase Accuracy and Precision of 1H NMR Urine Metabolomics.

Urine is an equally attractive biofluid for metabolomics analysis, as it is a challenging matrix analytically. Accurate urine metabolite concentration estimates by Nuclear Magnetic Resonance (NMR) are hampered by pH and ionic strength differences between samples, resulting in large peak shift variability. Here we show that calculating the spectra of original samples from mixtures of samples using linear algebra reduces the shift problems and makes various error estimates possible. Since the use of two-dimensional (2D) NMR to confirm metabolite annotations is effectively impossible to employ on every sample of large sample sets, stabilization of metabolite peak positions increases the confidence in identifying metabolites, avoiding the pitfall of oranges-to-apples comparisons.

Study of the effect of water dosage and compaction on the physico-mechanical characteristics of a mixture of earth (Avédji clay soil) and coconut fibers

The objective of this study is to contribute to the popularization of knowledge on the earth construction sector by studying the influence of the variation in the quantity of water and the compaction energy on the physico-mechanical properties of a mixture of earth (Avédji clay soil) and coconut plant fibers. · To achieve this, we carried out : · characterization of clay soil and coconut fibers ; · a pre-formulation to achieve good workability and manageability of the soil-fiber mixture (this made it possible to adopt 80% clay soil and 20% coconut plant fibers) ; · the formulation and preparation of soil-fiber mixture samples with two compaction modes: vibration and staking and variations in the quantity of water from 16% to 20% in increments of 2% ; · determination of the mechanical properties of mixtures by compression and tensile tests by bending in the hardened state. The results obtained show that for a water variation of 16% and 20%, the staked specimens give higher compressive strengths than the vibrated specimens; while at 18% the resistances are approximately the same. In traction, the resistance varies in the same direction as the water variation and the addition of fibers makes it possible to improve this tensile resistance by bending. Furthermore, the best mechanical strengths are obtained in traction, which is about 1.00 MPa, and in compression, which is about 1.544 MPa for a water variation of 20% and for compaction energy by staking precisely at compression.

Extreme Learning Machine Combined With Whale Optimization Algorithm for Spectral Quantitative Analysis of Complex Samples

ABSTRACTExtreme learning machine (ELM) is combined with the discretized whale optimization algorithm (WOA) for spectral quantitative analysis of complex samples. In this method, the spectral variables selected by the discretized WOA were used to build the ELM model. Before establishing the model, the activation function and the number of hidden nodes in ELM as well as the transfer function of the discretized WOA are determined. Furthermore, the predictive performance of the full‐spectrum partial least squares (PLS), ELM, and WOA‐ELM models was compared with four complex sample datasets: blood, light gas oil and diesel fuels, ternary mixture, and corn samples using root mean square error of prediction (RMSEP) and correlation coefficient (R). The results show that the WOA‐ELM model has the best prediction accuracy compared to full‐spectrum PLS and ELM models. Therefore, the proposed method provides a novel approach for the quantitative analysis of complex samples.

Development of a rapid and fully automated factor VIII inhibitor assay, insensitive to emicizumab, and a lowest level of quantification of 0.2 BU/mL

BackgroundFactor (F)VIII inhibitors are measured using labor- and resource-expensive Nijmegen or Bethesda assays, which lack sensitivity for low-titer inhibitors and show high variations in quality surveys, mainly because of manual assay procedures. ObjectivesThe goal of this study was the development of a fast and fully automated FVIII inhibitor assay by using recombinant (r)FVIII as substrate and dedicated equipment for execution of the test. MethodsA new rapid, fully automated, FVIII inhibitor assay is presented, the core of which is use of full-length recombinant FVIII (rFVIII; Kovaltry, Bayer) as inhibitor substrate instead of plasma FVIII, resulting in rapid binding of inhibitors to rFVIII due to absence of von Willebrand factor. Dramatic shortening of incubation time facilitated full automation on an analyzer capable of 3 subsequent sample dilution steps and 3 reagent additions. Equal volume mixtures of sample and rFVIII (1.0 U/mL) were incubated for 10 minutes at 37 °C, whereafter remaining FVIII activity was analyzed with a kinetic chromogenic assay, allowing inhibitor activity calculation without preceding FVIII activity calibration, using a Ceveron s100 analyzer (Technoclone). ResultsMean titer in 60 nonhemophiliacs was 0.0 BU/mL (SD, 0.1), yielding a limit of blank of 0.1 BU/mL and lower limit of quantification of 0.2 BU/mL. Analyses were performed with the new method and a Nijmegen assay in 28 inhibitor-positive clinical samples, 14 containing emicizumab and 14 without. Correlation coefficient in emicizumab-free type I inhibitor samples was 1.0. Emicizumab dependency of the method was excluded in spiking experiments with inhibitor-positive samples. Reproducibility was tested by analyzing 7 samples in 3 laboratories for 5 days, twice daily; coefficients of variation of all samples were <15%. ConclusionWe present development data of a sensitive and specific rapid, automated FVIII inhibitor assay generating results within 20 minutes that is less resource-intensive than standard assays with potential to improve assay variability.

Analysis of crumb rubber content influence on damage evolution and pattern recognition of rubberised epoxy asphalt mixture using acoustic emission techniques

ABSTRACT The application of coarse crumb rubber (CR) to toughen the epoxy asphalt mixture has emerged as a viable choice. However, the evolution rule of strength and damage modes of mixtures with different crumb rubber contents remains elusive. The objective of this study is to clarify the failure mechanisms in rubberized epoxy asphalt mixture combined acoustic emission (AE) data and k-means clustering theory. Four types of epoxy asphalt mixture samples are tested with the monitor of AE sensors. Based on the temporal and frequential features of AE signals, damage evolution is evaluated by the Weibull function, b-value, and the relationship between the raise angle and average frequency at the peak loading. Moreover, the k-means algorithm is conducted to cluster the AE events and damage characteristics after pre-processing the data. The test results indicate that CR particles enhance the toughness of epoxy asphalt mixtures and the mixtures with fewer CR are susceptible to occur sudden fracture due to brittle coarse aggregates. The k-means method effectively identifies AE events into four types of damaged behaviours. The findings offer valuable insights into the strength attenuation, modification characteristics, damage evolution and damage modes of rubberized epoxy asphalt mixtures, contributing to the development of more durable and resilient asphalt materials.

The Preservation and Spectral Detection of Historic Museum Specimen Microbial Mat Biosignatures Within Martian Dust: Lessons Learned for Mars Exploration and Sample Return.

The key building blocks for life on Mars could be preserved within potentially habitable paleo-depositional settings with their detection possible by utilizing mid-infrared spectroscopy; however, a definite identification and confirmation of organic or even biological origin will require the samples to be returned to Earth. In the present study, Fourier-transform infrared (FTIR) spectroscopic techniques were used to characterize both mineralogical and organic materials within Mars dust simulant JSC Mars-1 and ancient Antarctic cyanobacterial microbial mats from 1901 to 1904 Discovery Expedition. When FTIR spectroscopy is applied to cyanobacterial microbial mat communities, the resulting spectra will reflect the average biochemical composition of the mats rather than taxa-specific spectral patterns of the individual organisms and can thus be considered as a total chemical analysis of the mat colony. This study also highlights the potential difficulties in the detection of these communities on Mars and which spectral biosignatures will be most detectable within geological substrates. Through the creation and analysis of a suite of dried microbial mat material and Martian dust simulant mixtures, the spectral signatures and wavenumber positions of CHx aliphatic hydrocarbons and the C-O and O-H bands of polysaccharides remained detectable and may be detectable within sample mixtures obtained through Mars Sample Return activities.

Emissions of CO2 and CH4 from Agricultural Soil with Kitchen Compost at Different Temperatures

Emissions of CO2 from the soil are mainly derived from soil microbial respiration, whereas CH4 emissions originate from anaerobic degradation of organic matter via microbial processes. Kitchen waste compost is used in the agricultural sector to improve soil quality. However, abiotic CO2 and CH4 emissions from soils amended with kitchen waste compost under aerobic conditions remain uncertain. Temperature plays an important role in organic matter decomposition in both biotic and abiotic pathways. This study aimed to evaluate biotic and abiotic emissions of CO2 and CH4 from soils receiving kitchen compost at different temperatures. Ten grams of soil amended with or without 0.1 g kitchen compost (1%) were sterilized or non-sterilized. The mixture and soil-only samples were incubated in 100-mL glass bottles at 20, 30, and 35 °C for 28 d under an aerobic condition. The results showed that CO2 and CH4 emissions increased at higher temperatures and compost application rates (p < 0.05). Emissions of CO2 mainly occurred via biotic pathways. Abiotic processes were potential pathways for CH4 generation, particularly at high temperatures of 35 °C. There was 20–24% of C in kitchen compost changed to CO2 and less than 0.1% to CH4. Our results suggest that global warming enhances abiotic CO2 and CH4 emissions and may contribute to further global warming.

Effects of Incorporating Ionic Crosslinking on 3D Printing of Biomass-Fungi Composite Materials.

Biomass-fungi composite materials primarily consist of biomass particles (sourced from agricultural residues) and a network of fungal hyphae that bind the biomass particles together. These materials have potential applications across diverse industries, such as packaging, furniture, and construction. 3D printing offers a new approach to manufacturing parts using biomass-fungi composite materials, as an alternative to traditional molding-based methods. However, there are challenges in producing parts with desired quality (for example, geometric accuracy after printing and height shrinkage several days after printing) by using 3D printing-based methods. This paper introduces an innovative approach to enhance part quality by incorporating ionic crosslinking into the 3D printing-based methods. While ionic crosslinking has been explored in hydrogel-based bioprinting, its application in biomass-fungi composite materials has not been reported. Using sodium alginate (SA) as the hydrogel and calcium chloride as the crosslinking agent, this paper investigates their effects on quality (geometric accuracy and height shrinkage) of 3D printed samples and physiochemical characteristics (rheological, chemical, and texture properties) of biomass-fungi composite materials. Results show that increasing SA concentration led to significant improvements in both geometric accuracy and height shrinkage of 3D printed samples. Moreover, crosslinking exposure significantly enhanced hardness of the biomass-fungi mixture samples prepared for texture profile analysis, while the inclusion of SA notably improved cohesiveness and springiness of the biomass-fungi mixture samples. Furthermore, Fourier transform infrared spectroscopy confirms the occurrence of ionic crosslinking within 3D printed samples. Results from this study can be used as a reference for developing new biomass-fungi mixtures for 3D printing in the future.

Effects of ionic strength and bentonite ratio on the migration of Cr(VI) in clayey soil-bentonite engineered barrier.

Soil-bentonite (S-B) barriers have been widely used for heavy metal pollution containment. This study conducted batch adsorption tests and diffusion-through tests to evaluate how ionic strength and bentonite ratio influence the migration of Cr(VI) in natural clay-bentonite mixtures. The test results indicated that the adsorption of Cr(VI) exhibited an obvious anion adsorption effect, the pH of the soil mixture increased with the addition of bentonite, resulting in a decrease in the positive surface charge. This change led to a decrease in Cr(VI) adsorption capacity, from 775.19 mg/kg for pure clay to 378 mg/kg for mixture samples with excessive bentonite. Furthermore, as the ionic strength increases from 0 to 0.1 M, the Cr(VI) adsorption capacity increases slightly due to the weakening of electrostatic repulsion on the clay particle surface, but the effective diffusion coefficient (De) increases by 21.97%. The compression of the diffusion double layer (DDL) under high ionic strength conditions enlarges the diffusion path and enhances the migration of Cr(VI) through the pore flow paths. Moreover, hydrated bentonite effectively fills the interaggregate pores of natural clay, thus creating narrower and more tortuous flow paths. However, excessive bentonite increases the pH value and pore volume, resulting in changes to the soil microstructure and disrupting the continuous skeleton of natural clay, which is unfavorable for Cr(VI) containment. Based on the study of the Cr(VI) contaminated site, a bentonite ratio of 2:10 is recommended for optimal natural performance of the natural clay-bentonite barrier.