Modelling and optimization of metals (As, Ca, Cd, Cr, Cu, Fe, Mg, and Pb) and Ethylene glycol butyl ether in paints using response surface method

Response surface methodology (RSM) and principal component analyses (PCA) modelling tools have been used in this study to quantitatively describe the interaction effects of more than one factor on system response for the modelling and optimization of experimental data. In Nigeria, there are no stringent policies in place by the government on paint production and this has led to unregulated paint products by producers in the commercial markets. Water-based paints currently available in Nigerian market were sampled. Experimental data of Metals (As, Ca, Cd, Cr, Cu, Fe, Mg, and Pb) and Ethylene glycol butyl ether (Volatile organic compounds (VOC)) measured using Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) and Gas Chromatography-Flame Ionisation Detector (GC-FID), respectively was used to develop a mathematical model. The principal component analyses were explained with a cumulative variance of 82% for the VOC and 76% for metals based on manufacturers. Estimated responses were compared with the experimentally determined responses and prediction capabilities of Response Surface Methodology. In the RSM, the 2 developed model had R value of 0.9569, with optimized value at 0.10 % (1000ppm) of Ethylene glycol butyl ether and concentration (ppm) ranges of As (383.0-1,930.0), Ca (614.0-10,400.0), Cd (98.0-2,000.0), Cr (10.3- 225.0), Cu (133.0-1,840.0), Fe 742.0-2,910.0, Mg (4,000.0-99,510.0), Pb (170.0-3,230.0). The correlation and optimization study employed are applicable for assessing the impact of hazardous air pollutants on indoor air quality and a good applicability in paint industries to produce products within the set limit of international standards. For the purpose of reducing sick building syndrome and protecting public health, it was important to investigate paints and sealers extensively. Keywords: VOCs; Paint; metals; Ethylene glycol butyl ether; Response Surface Method

Assessment of genetic variability among accessions of okra (Abelmoschus esculentus L. Moench)

Okra yields are low in West and Central Africa and factors including narrow genetic base of available germplasm have been implicated. An assessment of genetic variability among germplasm from various sources and knowledge of trait contributions to these variations is crucial to the success of okra breeding program. Eighteen okra accessions were evaluated during the 2020 cropping season in Nigeria to assess the genotypes for genetic diversity, group the accessions into clusters and identify traits that chiefly accounted for the variations among the genotypes. Data obtained were subjected to analysis of variance (ANOVA), metroglyph and principal component analyses (PCA). ANOVA revealed significant accession mean squares for majority of the measured traits. Metroglyph analysis grouped the accessions into four clusters with members of Cluster IV generally high-yielding, early-maturing and short genotypes. NGB00353 and NGB00356 that were among genotypes with high total index scores were members of Cluster IV. The first four principal components (PCs) accounted for 80% of the total observed variation. PC1 with the highest discriminatory power was loaded with days to budding, internode length, pod yield.plot−1 and the number of pods.plant−1. The variation within and between clusters could be explored in okra breeding program.

Genetic diversity and trait profiles of some Amaranthus genotypes

Knowledge of the pattern of trait variation among accessions, and the trait profiles of the accessions is crucial for improvement of a crop. Twenty-one Amaranthus accessions were evaluated in 2018 and 2019 to investigate the extent of genotypic diversity among the amaranth accessions and their trait profiles. Data were subjected to analysis of variance, and correlation and principal component analyses. Taking stem weight (SWT) as the yield, the accession × yield-trait combination (GYT) biplot was employed to investigate the trait profiles of the accessions. Accession, year, and accession × year mean squares were significant (P≤0.05/0.01) for most of the measured traits. The first three principal components explained 88.18% of observable variation among the accessions and identified plant height (PHT), number of leaves per plant (NOL), and root weight (RWT) as the major contributors. Significant (P≤0.01) correlation was observed in the association of SWT with NOL, TBM, and RWT. Accessions NGB00019 and NGB00061 were associated with the sector containing all the YT combinations considered. However, NGB00019 was identified as the best combiner of yield with other traits. Further studies involving more traits should determine the trait profiles of the remaining accessions.

Does the Ratio of Compounds in a Plant Volatiles Blend Remain Stable During Transmission by Wind?

For plant volatiles to mediate interactions in tritrophic systems, they must convey accurate and reliable information to insects. However, it is unknown whether the ratio of compounds in plant volatile blends remains stable during wind transmission. In this study, volatiles released from an odor source were collected at different points in a wind tunnel and analyzed. The variation in the amounts of volatiles collected at different points formed a rough cone shape. The amounts of volatiles collected tended to decrease with increasing distance from the odor source. Principal component analyses showed that the volatile profiles were dissimilar among different collection points. The profiles of volatiles collected nearest the odor source were the most similar to the released odor. Higher wind speed resulted in a clearer distinction of the spatial distribution of volatile compounds. Thus, variations in the ratios of compounds in odor plumes exist even during transport over short distances.

INVOLVEMENT OF WASTE FROM OIL AND GAS FIELDS IN TECHNOGENIC SOILS AND GROUND CONCRETE

The article considers the system of differentiation of oil and gas fields for the application of the technology of waste entrainment in man-made soils and soil-concrete on the territory of the plant. It names the indicators for which the mathematical analysis of the parameters by the principal component analyses is used. As a result, the analysis of the deposits of the Samara region was carried out. The universality of the new method is proven.

A method for highlighting differences between bacteria grown on nutrient agar using near infrared spectroscopy and principal component analysis

Fast diagnostic tools such as near infrared spectroscopy have recently gained interest for bacterial identification. To avoid a process involving microbial pellet or suspension preparation from Petri dishes for NIR analysis, direct screening from agar in Petri dishes was explored. This two-step study proposes a new procedure for bacterial screening directly on agar plates with minimal nutrient medium bias. Firstly, principal component analyses showed optimal discrimination between the genera Lactobacillus, Pseudomonas and Brochothrix on different culture media, in transmission mode and with the bottom of Petri dishes facing the light source. The repeatability of spectra in these conditions was assessed with an average coefficient of variation inferior to 5% in the 12,500–3680 cm−1 range. Secondly, 40 strains of Lactococcus and Enterococcus species were grown on Bennett agar and measured over a series of five assays. Principal component analyses highlighted better clustering according to genera and species and lower external bias while retaining the 8790–3680 cm−1 spectral range and applying an extended multiplicative scatter correction with an average agar spectrum as a reference, in comparison to raw data and standard multiplicative scatter correction.