From Fourier Transform Infrared Spectroscopy Research Articles

Multiscale Approach to Studying Biomolecular Interactions in Cellulose-Casein Adhesion.

Casein finds application as an eco-friendly adhesive for paper, wood, glass, etc. Casein being a protein can undergo conformational and microstructural changes during various processing steps involved in interfacial bonding. This study aims at understanding the multiscale contributions of these changes in casein to its adhesion to cellulose pressboards. Investigations spanning from molecular structure to macroscopic adhesion characteristics have been used in this work. The lap shear strength of casein bonded cellulose pressboards is found to increase with the increase in casein concentration. It was observed from Fourier transform infrared spectroscopy (FTIR) investigations along with microscopy and rheological studies that casein dispersions result in more α-helical conformations during the preconcentration process of casein dispersions. This results in increased hydrophobicity of the casein particles/aggregates, which in turn affects the wetting characteristics and the adhesion behavior. Casein compositions lacking α-helices were found to enhance the bonding strength of casein with cellulose. The present study shows that the adhesion between casein and microporous cellulose substrate has contributions at the multiscale originating from the polar-polar interactions of casein and cellulose molecules, conformational changes in the protein structure of casein during drying, microstructure of casein particles in the dispersion, and the microporous nature of the cellulose boards. These interactions at multiple scales can be tuned to suit different adhesive applications using casein.

Phytofabrication of Silver Nanoparticles and Their Potent Antifungal Activity against Phytopathogenic Fungi

Fungal plant pathogens cause huge losses in agricultural production by decreasing crop yield and quality. To reduce crop loss from fungal damage, various synthetic fungicides are applied indiscriminately in agricultural practice. The majority of synthetic fungicides are non-biodegradable, and several critical human health risks are associated with them. Green synthesis nanotechnology offers an effectual, cost-effective, ecofriendly, and innocuous method for the synthesis of green nanofungicides, an excellent replacement for synthetic chemical fungicides. Origanum majorana is an aromatic herb with immense pharmacological and medicinal properties. In this context, the present study used the leaves of O. majorana to synthesize silver nanoparticles. The biosynthesized particles showed an absorption peak at 441 nm with ultraviolet-visible spectrophotometry (UV-Vis). The spectra obtained from Fourier transform infrared spectroscopy (FT-IR) of O. majorana extract and AgNPs showed a myriad of functional groups corresponding to vital biomolecules that act as capping and reducing agents. The synthesized silver nanoparticles were spheroidal, and their size measured between 8 nm and 42 nm, as depicted by transmission electron microscopy (TEM). The energy-dispersive X-ray spectrum (EDX) showed a silver peak at 3 keV. The phytofabricated silver NPs demonstrated robust inhibitory activity on the mycelial growth of A. alternata f sp. lycopersici (87%), followed by Pestalotiopsis mangiferae (85%), Macrophomina phaseolina (78%), and Colletotrichum musae (75%). The minimum inhibitory concentration value for A. alternata. f sp. lycopersici and Pestalotiopsis mangiferae was 2 μg/mL, while the minimum fungicidal concentrations were 4 and 8 μg/mL, respectively. Additionally, the fabricated AgNPs induced severe damaging and destructive effects to the morphology of hyphae and conidia, as witnessed by scanning electron microscopy studies.

Sequence patterns and signatures: Computational and experimental discovery of amyloid-forming peptides.

Screening amino acid sequence space via experiments to discover peptides that self-assemble into amyloid fibrils is challenging. We have developed a computational peptide assembly design (PepAD) algorithm that enables the discovery of amyloid-forming peptides. Discontinuous molecular dynamics (DMD) simulation with the PRIME20 force field combined with the FoldAmyloid tool is used to examine the fibrilization kinetics of PepAD-generated peptides. PepAD screening of ∼10,000 7-mer peptides resulted in twelve top-scoring peptides with two distinct hydration properties. Our studies revealed that eight of the twelve in silico discovered peptides spontaneously form amyloid fibrils in the DMD simulations and that all eight have at least five residues that the FoldAmyloid tool classifies as being aggregation-prone. Based on these observations, we re-examined the PepAD-generated peptides in the sequence pool returned by PepAD and extracted five sequence patterns as well as associated sequence signatures for the 7-mer amyloid-forming peptides. Experimental results from Fourier transform infrared spectroscopy (FTIR), thioflavin T (ThT) fluorescence, circular dichroism (CD), and transmission electron microscopy (TEM) indicate that all the peptides predicted to assemble in silico assemble into antiparallel β-sheet nanofibers in a concentration-dependent manner. This is the first attempt to use a computational approach to search for amyloid-forming peptides based on customized settings. Our efforts facilitate the identification of β-sheet-based self-assembling peptides, and contribute insights towards answering a fundamental scientific question: "What does it take, sequence-wise, for a peptide to self-assemble?".

Evidence for Caffeine’s Positive Impact on HOR/HER Activity through Water Rearrangement As Opposed to Direct Influence on the Interfacial Electric Field

The puzzling pH dependence of HOR/HER leading to the approximately 2 orders of magnitude loss in platinum group metal (PGM) activity in base has hindered both the practical design of electrochemical devices as well as the fundamental understanding of electrode/electrolyte interfaces.1 Explanations for this effect have ranged from the presence of adsorbates specific to alkaline conditions,2 shifts in the electrode potential of zero free charge (pzfc) and subsequent strengthening of the interfacial electric field,3 the orientation of interfacial water molecules, and changes in the binding energy of reaction intermediates.4–6 Recently, several innovative in situ techniques have been used to probe these theories, ranging from Fourier Transform Infrared Spectroscopy (FTIR) to X-Ray Absorption Spectroscopy (XAS), as well as novel computational studies to isolate the contributions of surface adsorbed hydroxide and water.2–4,7 Additionally, the identification of caffeine as a “double-layer dopant” capable of improving HOR/HER activity 5-fold on Pt(111) has provided the field with a model system with which to systematically test these theories.8 Despite this, an overarching understanding of the mechanism and caffeine’s promoting role is still unclear, and a more rigorous analysis of the electrode surface is necessary.The electrochemical interface is traditionally viewed with a double layer model, with specific electrochemical adsorbates existing in the Inner Helmholtz Plane (IHP), the first layer of non-adsorbates at the Outer Helmholtz Plane (OHP), and water in abundance. One leading theory used to understand the activity loss from acid to alkaline environments is the decrease in surface potential relative to the pzfc in base resulting in stronger electric fields which restrict the approach of reactive intermediates to the IHP/OHP. Caffeine is suspected of reducing the IEF strength through decreasing the pzfc to relevant HOR/HER potentials, creating an acidic like environment. In this work, we challenge this notion by using SEIRAS with CO as a probe molecule to directly measure the interfacial field strength in 0.1 M KOH solutions with the model caffeine system showing HOR/HER enhancement, as well as different concentrations of various organic species with no promoting kinetic impact. FTIR studies using CO as a probe molecule to measure stark tuning rates have long been used to directly measure the interfacial electric field strength, dictated by the majority species in the OHP.9,10 The low ST rate of 22 cm-1V-1 found for all of these species in our experiments, regardless of their impact on HOR/HER kinetics, implies reductions in IEF are not solely responsible for the KOH-caffeine system’s increased activity. Rather, caffeine induces changes to the interfacial water structure as evidenced by differences in water’s ν(O-H) stretching modes, allowing for more facile kinetics, the main parameter responsible for the “apparent pH dependence” of PGM HOR/HER. Durst, J. et al. New insights into the electrochemical hydrogen oxidation and evolution reaction mechanism. Energy Environ. Sci. 7, 2255–2260 (2014).McCrum, I. T. & Koper, M. T. M. The role of adsorbed hydroxide in hydrogen evolution reaction kinetics on modified platinum. Nat. Energy 5, 891–899 (2020).Sarabia, F. J., Sebastián-Pascual, P., Koper, M. T. M., Climent, V. & Feliu, J. M. Effect of the Interfacial Water Structure on the Hydrogen Evolution Reaction on Pt(111) Modified with Different Nickel Hydroxide Coverages in Alkaline Media. ACS Appl. Mater. Interfaces 11, 613–623 (2019).Liu, E. et al. Interfacial water shuffling the intermediates of hydrogen oxidation and evolution reactions in aqueous media. Energy Environ. Sci. 13, 3064–3074 (2020).Yang, X., Nash, J., Oliveira, N. J., Yan, Y. & Xu, B. Understanding the pH Dependence of Underpotential Deposited Hydrogen on Platinum. Angew. Chemie - Int. Ed. 58, 17718–17723 (2019).Rebollar, L. et al. On the relationship between potential of zero charge and solvent dynamics in the reversible hydrogen electrode. J. Catal. 398, 161–170 (2021).Cheng, T., Wang, L., Merinov, B. V. & Goddard, W. A. Explanation of Dramatic pH-Dependence of Hydrogen Binding on Noble Metal Electrode: Greatly Weakened Water Adsorption at High pH. J. Am. Chem. Soc. 140, 7787–7790 (2018).Intikhab, S. et al. Caffeinated Interfaces Enhance Alkaline Hydrogen Electrocatalysis. ACS Catal. 10, 6798–6802 (2020).Lambert, D. K. Vibrational Stark effect of CO on Ni(100), and CO in the aqueous double layer: Experiment, theory, and models. J. Chem. Phys. 89, 3847–3860 (1988).Anderson, M. R., Blackwood, D. & Pons, S. The behavior of the infrared spectrum of carbon monoxide adsorbed at platinum electrodes from non-aqueous solvents. J. Electroanal. Chem. 256, 387–395 (1988). Figure 1

An Aqueous Binary Binder for Silicon-Based Electrodes

The relatively low coulombic efficiency (CE), especially the high initial capacity loss (ICL), and short cycle life are two major obstacles limit the wide adoption of Si-based materials as anodes of commercial lithium-ion batteries (LIBs). In this work, we introduced an aqueous binary binder composed of polyacrylic acid (PAA) and a water-soluble polymer to a Si-based electrode. Used as anodes of LIBs, the Si-based electrodes with the binary binder exhibited lower ICL and longer cycle life than those with PAA binder. The improved battery performance is ascribed to the unique electrode structure with the binary binder. The analysis from Fourier-transform infrared spectroscopy (FTIR) reveals that the intermolecular hydrogen bonds has been formed between PAA and the new polymer. The formation of hydrogen bonds could affect the properties of slurry for electrode coating and the structure of dried electrodes. Compared to the PAA binder, the new binary binder increases the viscosity of aqueous slurries at low shear rates and prompts the shear thinning, which benefit the preparation of slurries with high stability. Observations from the electron microscopy reveal that a relative porous structure was generated in the electrodes with the binary binder, compared with those with PAA binder. The porous structure could not only facilitate the electrolyte transport, but also accommodate the large volume expansion of Si during the charge/discharge processes. In addition, a thin solid-electrolyte-interface (SEI) film was found at the surface of cycled electrodes with the binary binder.Key words: aqueous binder coulombic efficiency Si-based anode lithium-ion battery

Overlooked Impact of Interchain H-Bonding between Cross-Links on the Mechanical Properties of Thermoset Polyurethane Elastomers

Thermoset polyurethane elastomers made from poly(3,3-bis(azidomethyl) oxetane with tetrahydrofuran) and various multifunctional isocyanate cross-linkers were compared to uncover a new mechanism of modulating the mechanical properties. Extra hydrogen bonding motifs, such as urethane or urea, were built in the cross-linkers and were proved to essentially determine the stiffness and toughness of the elastomers, while the covalent cross-linking densities of both networks were controlled strictly at the same level. The impact of interchain H-bonding on the mechanical properties of the polyurethane thermoset was unprecedently emphasized and supported by evidence from Fourier-transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), and low-field nuclear magnetic resonance (LFNMR).

Isolation, Structural Characterization, and Biological Activity of the Two Acidic Polysaccharides from the Fruits of the Elaeagnus angustifolia Linnaeus.

Elaeagnus angustifolia Linnaeus is a medicinal plant and its fruit has pharmacological activity such as antiinflammatory, antiedema, antinociceptive, and muscle relaxant functions, etc. Two acidic homogeneous polysaccharides (EAP-H-a1 and EAP-H-a2) were isolated from the fruits of Elaeagnus angustifolia L. through DEAE-52 and Sephadex G-75 column chromatography, and the physicochemical, structural properties, and biological activities of the polysaccharides were investigated. Both EAP-H-a1 and EAP-H-a2 were composed of Rha, Ara, Xyl, Glc, and Gal with the molar ratios of 13.7:20.5:23.3:8.8:33.4 and 24.8:19.7:8.2:8.4:38.6, respectively, and with the molecular weights of 705.796 kDa and 439.852 kDa, respectively. The results obtained from Fourier transform infrared spectroscopy (FTIR) confirmed the polysaccharide nature of the isolated substances. Congo red assay confirmed the existence of a triple-helix structure. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis revealed that EAP-H-a1 and EAP-H-a2 had irregular fibrous, filament-like surfaces; and both had crystalline and amorphous structures. Bioactivity analysis showed that the crude polysaccharide, EAP-H-a1, and EAP-H-a2 had clear DPPH and ABTS free radical scavenging activity, and could promote the secretion of NO and the phagocytic activities of RAW 264.7 and THP cells, which showed clear antioxidant and immuno-regulatory activity. These results indicated that Elaeagnus angustifolia L fruit acidic polysaccharides may have potential value in the pharmaceutical and functional food industries.

Visible Light-Driven Photocatalytic Degradation of Ciprofloxacin, Ampicillin and Erythromycin by Zinc Ferrite Immobilized on Chitosan

This study investigated the synthesis of zinc ferrite immobilized on chitosan (ZnFe2O4@Chitosan) and its application in the photodegradation of ciprofloxacin (CIP), ampicillin (AMP) and erythromycin (ERY) in aqueous solution. Results from Fourier transform infrared spectroscopy (FTIR) revealed peaks suggesting its synthesis, while signals from X-ray diffraction (XRD) showed diffraction patterns confirming the synthesis of ZnFe2O4@Chitosan with a crystallite size of 35.14 nm. Scanning electron microscopy (SEM) revealed a homogeneous morphology with a surface area of 12.96 m2 g−1 from the Brunauer–Emmett–Teller (BET) analysis. The vibrating sample magnetometry (VSM) result revealed a saturation magnetization of 2.38 emu g−1. The photodegradation study of CIP, AMP and ERY showed that both photodegradation and adsorption were taking place at the same time with the percentage degradation efficiency in the order CIP (99.80 ± 0.20%) > AMP (94.50 ± 0.10%) > ERY (83.20 ± 0.20%). ZnFe2O4@Chitosan exhibited high stability with capacity > 90% even at the 15th regeneration cycle, suggesting a viable economic value of ZnFe2O4@Chitosan.

Inactivation efficacy and mechanisms of atmospheric cold plasma on Alicyclobacillus acidoterrestris: Insight into the influence of growth temperature on survival.

The bactericidal effect of dielectric barrier discharge-atmospheric cold plasma (DBD-ACP, 20, and 30 kV) against Alicyclobacillus acidoterrestris on the saline solution and apple juice was investigated. Results show that DBD-ACP is effective for the inactivation of A. acidoterrestris by causing significant changes in cell membrane permeability and bacterial morphology. The effect of culture temperatures on the resistance of A. acidoterrestris to DBD-ACP was also studied. A. acidoterrestris cells grown at 25°C had the lowest resistance but it was gradually increased as the culture temperature was increased (25–45°C) (p < 0.05). Moreover, results from Fourier transform infrared spectroscopy (FT-IR) and Gas Chromatography-Mass Spectrometer (GC-MS) analysis showed that the increase in the culture temperature can gradually cause the decreased level of cyclohexaneundecanoic acid in the cell membrane of A. acidoterrestris (p < 0.05). In contrast, cyclopentaneundecanoic acid, palmitic acid, and stearic acid showed an increasing trend in which the fluidity of the bacterial cell membrane decreased. This study shows a specific correlation between the resistance of A. acidoterrestris and the fatty acid composition of the cell membrane to DBD-ACP.

Use of Industrial Silica Sand as a Fine Aggregate in Concrete—An Explorative Study

Industrial silica sand is a by-product obtained from the industries like paint, paper, rubber etc. It has a similar property with river sand and&amp; M sand. This study explores the effect of high content of silica sand as a partial replacement for fine aggregate for concrete making in construction purpose. In this present research four types of silica sand from two different industrial units (coarser silica sand (VC and TC) and finer silica sand (VF and TF)) were used. The physical classification and morphology observation of silica sand through scanning electron microscope (SEM), energy-dispersive X-ray (EDAX), X-ray fluorescence (XRF) is examined. Fresh and hardened concrete properties were performed for the six sand samples, with two grades (M20 and M30) of concrete. No new compositions or phases were identified in silica sand concrete. Both fine and coarse silica sands were finer than river sand and M sand, as evaluated from the physical classification. The workability of silica sand mix at a fresh state improves the concrete performance up to 40%. The mix, which contains 80% coarser silica sand (TC) with 20% river sand, attained the maximum compressive strength of 34.5 Mpa and tensile strength of 3.5 Mpa at 28 days, which was the greatest of all the mixes. The combination of silica sand and river sand or M sand showed the superior impact of the concrete over the discrete concrete. SEM images showed the well-developed hydrated products like calcium silicate hydrate (CSH), calcium hydroxide (CH) and ettringite in all concrete mixes. It was observed from the XRD pattern that all concrete mixes containing silica sand have a high peak of quartz (SiO2), and calcium silicate hydrate (CSH) exhibits the formation of hydration products in the concrete. Similar stretching and bending patterns of silica sand concrete relates the pattern of nominal sand concrete as observed from Fourier-transform infrared spectroscopy (FTIR).

The first evidence of microplastic presence in pumice stone along the coast of Thailand: A preliminary study

In February and March 2022, a large amount of pumice stone appeared along the shoreline of Thailand. Pumice is a type of extrusive volcanic rock, and since there are no volcanoes in the Gulf of Thailand, an interesting question was where the pumice stones originated from. Another question was whether the pumice could be a vehicle for microplastics (MPs) which could then journey across the ocean until reaching the coast of Thailand. A preliminary study was begun, which randomly collected samples from seven beaches in five provinces along the coast of Thailand. Grayish-green pumice stones are tiny, porous, and lightweight, ranging from 0.3 to 5.0 cm in size. The examination found 5.7–12.6 MP items per pumice stone. Most of the MP particles observed were less than 1 mm in length. From Fourier transform infrared spectroscopy (FTIR) analysis, the MPs were characterized as polystyrene, polypropylene, poly (ethylene terephthalate) (PET), rayon, and nylon. The MP could have entered the holes in pumice stones while floating on the water surface over long periods. From the seasonal flow patterns, it was revealed that pumice from the South China Sea was more likely to have floated with surface currents into the Gulf of Thailand

Floating TiO2-Cork Nano-Photocatalysts for Water Purification Using Sunlight

In the present study, titanium dioxide (TiO2) nano-photocatalysts were synthesized through microwave irradiation. In a typical microwave synthesis, TiO2 nanomaterials were simultaneously produced in powder form and also directly covering cork substrates. The TiO2 nanopowder was analyzed by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM), revealing that the solvothermal microwave synthesis resulted only in the TiO2 anatase phase. From Fourier-transform infrared spectroscopy (FTIR), cork’s organic species, along with bands of TiO2, were detected. UV–VIS absorption spectrum revealed an absorption extension to the visible region, since a brown powdered TiO2 product was obtained. Very fine nanoparticles were observed displaying a nearly spherical shape that agglomerates in larger particles. These larger particles fully covered the surface of the honeycomb cork cells, originating TiO2 functionalized cork platforms. The TiO2 functionalized substrates were further tested as floating photocatalysts and their photocatalytic activity was assessed from rhodamine B degradation under solar simulating light and natural sunlight. Reusability tests were also performed under natural sunlight. The strategy applied in this research work allowed the production of green and low-cost cork platforms based on TiO2 photoactive materials with the ability to purify polluted water under natural sunlight.

Physicochemical and Microstructural Analyses of Pepsin-Soluble Collagens Derived from Lizardfish (Saurida tumbil Bloch, 1795) Skin, Bone and Scales.

Reducing food waste is critical for sustainability. In the case of fish processing, more than sixty percent of by-products are generated as waste. Lizardfish (Saurida tumbil Bloch, 1795) is an economically important species for surimi production. To address waste disposal and maximize income, an effective utilization of fish by-products is essential. This study aims to isolate and characterize pepsin-soluble collagens from the skin, bone and scales of lizardfish. Significant differences (p < 0.05) in the yields of collagen were noted with the highest yield recorded in pepsin-soluble skin collagen (PSSC) (3.50 ± 0.11%), followed by pepsin-soluble bone collagen (PSBC) (3.26 ± 0.10%) and pepsin-soluble scales collagen (PSCC) (0.60 ± 0.65%). Through SDS–polyacrylamide gel electrophoresis, the presence of two alpha chains were noted and classified as type I. From Fourier transform infrared spectroscopy (FTIR) analysis, the triple-helix structure of the collagen was maintained. The X-ray diffraction and UV visible spectra characteristics of the lizardfish collagens in this study are similar to the previously reported fish collagens. In terms of thermostability, PSSC (Tmax = 43.89 °C) had higher thermostability in comparison to PSBC (Tmax = 31.75 °C) and PSCC (Tmax = 30.54 °C). All pepsin-soluble collagens were highly soluble (>70%) in acidic conditions (particularly at pH 4.0) and at low sodium chloride concentrations (0–30 g/L). Microstructural analysis depicted that all extracted collagens were multi-layered, irregular, dense, sheet-like films linked by random coiled filaments. Overall, pepsin-soluble collagens from lizardfish skin, bone and scales could serve as potential alternative sources of collagens.

Green synthesis of oxidized starch with a novel catalyst based on Fe3O4 nanoparticles and H2O2 reagent to form thermoplastic as a stable gel coating on the cardiovascular stents

Oxidation of starch is one of the most commonly used approaches to improve its properties in the thermoplastic (TP) reactions. Iron oxide nanoparticle (IONP) (8.2 ± 1.5 nm) was used as a novel catalyst for this reaction. The functional groups of the carbonyl (COH) and the carboxyl (COOH) were obtained about of 7–12.2 % and 0.03–0.3 %. TP reaction and then electrospray technique of oxidized starch were used for the thin-film coating. The swelling ratio of the gelled thermoplastic structure with IONP (198 ± 9 % at 180 min) was lower than the sample without NP (193 ± 8 % at 90 min). The results from fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (HNMR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) reveal desirable chemical and crystalline changes. Scanning electron microscopy (SEM) analysis was used to determine the thickness of the thin film (1.4 ± 0.2 μm) and the size of the electrosprayed droplets (172 ± 45 nm). Cytotoxicity studies of HUVEC and L929 cell lines against the extracts have shown appropriate biocompatibility. The blood compatibility analysis demonstrated proper results for (nanocomposite) NC. The results show that NC coated on metal surfaces can be used in medical approaches with drug delivery capability.

Hydrolytic, thermal and radiation stability of modified urea-formaldehyde composites: Influence of montmorillonite particle size

Urea-formaldehyde (UF) composites with a formaldehyde/urea (FA/U) ratio = 0.8 and different particle sizes of montmorillonite (MMT), namely UF/KSF and UF/K10 were synthesized. The hydrolytic stability of modified UF composites was determined by measuring the content of the liberated formaldehyde of modified UF composites after acid hydrolysis. The synthesized modified UF composites were irradiated (50 kGy) and the effect of γ–irradiation was evaluated on the basis of these thermal behaviors. The thermal behavior was studied by non-isothermal thermo-gravimetric analysis (TG), differential thermo-gravimetry (DTG), and differential thermal analysis (DTA) supported by data from Fourier transform infrared spectroscopy (FTIR). The minimum percentages of free (0.4%) and liberated (1.2%) formaldehyde were obtained in the UF/KSF composite. The modified UF/KSF composite shows better radiation resistance than the modified UF/K10 composite. The shift of temperature values for the selected mass losses (T5%) to higher temperatures indicates an increase in the thermal stability of the UF/K10 composite after γ–irradiation. γ–irradiation causes a decrease in the absorption intensity of bands in the FTIR spectrum of a modified UF/KSF composite and an increase in the absorption intensity of bands in the FTIR spectrum of a modified UF/K10 composite.

Fourier transform infrared spectrum pre-processing technique selection for detecting PYLCV-infected chilli plants

Pre-processing is a crucial step in analyzing spectra from Fourier transform infrared (FTIR) spectroscopy because it can reduce unwanted noise and enhance system performance. Here, we present the results of pre-processing technique optimization to facilitate the detection of pepper yellow leaf curl virus (PYLCV)-infected chilli plants using FTIR spectroscopy. Optimization of a range of pre-processing techniques was undertaken, namely baseline correction, normalization (standard normal variate, vector, and min–max), and de-noising (Savitzky-Golay (SG) smoothing, 1st and 2 derivatives). The pre-processing was applied to the mid-infrared spectral range (4000 – 400 cm−1) and the biofingerprint region (1800 – 900 cm−1) then the discrete wavelet transform (DWT) was used for dimension reduction. The pre-processed data were then used as an input for classification using a multilayer perceptron neural network, a support vector machine, and linear discriminant analysis. The pre-processing method with the highest classification model accuracy was selected for the further use in the processing. It was seen that only the SG 1st derivative method applied to both wavenumber ranges could produce 100% accuracy. This result was supported by principal component analysis clustering. Thus, we have demonstrated that by using the right pre-processing technique, classification success can be increased, and the process simplified by optimization and minimization of the technique used.

Microwave-assisted carbon-based sulphonated melon seed peel catalyst development for the optimization of neem seed oil epoxidation using response surface methodology

Pure neem seed oil (NSO) was epoxidized via in situ conventional method using hydrogen peroxide and acetic acid in the presence of a microwave-assisted carbon-based sulphonated melon seed peel catalyst (MACSMSPC). The MACSMSPC was prepared via a two-step process (carbonization and sulphonation) using a microwave. The characterization results from Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Micrograph (SEM), X-Ray Diffraction (XRD), Brunauer-Emmet-Teller (BET) and X-ray fluorescence analysis (XRF) confirms the successful -SO3H group attachment to the solid catalyst. The modelling and optimization studies of the epoxidation process of NSO were performed using Box Behnken design implementing Response Surface Methodology (RSM) with catalyst concentration, time and temperature as the independent factors and oxirane value as the dependent factor. The ANOVA showed a second-order polynomial model with an R2 value of 0.9901, Adj R2 of 0.9774 and Pred R2 of 0.8415, indicating the significant correlation between the experimental values and predicted responses. The 3D plots showed that the process parameters significantly impacted the oxirane value. The optimal oxirane value of 9.816% was obtained at a catalyst concentration of 0.6, reaction time of 4 h, reaction temperature of 50 °C with a desirability of 1.000. also, characterizations result via FT-IR and GCMS on the epoxy NSO indicate the oxirane ring's successful attachment on the NSO.

Co-precipitation assisted preparation of Ag2O, CuO and Ag2O/CuO nanocomposite: Characterization and improved solar irradiated degradation of colored and colourless organic effluents

The photocatalytic degradation ability of Ag2O/CuO nanocomposite was investigated to remove colored and colorless dyes under solar light irradiation. The pristine metal oxides (Ag2O and CuO) were prepared using the co-precipitation method. The Ag2O/CuO nanocomposite was prepared by an ultra-sonication route. The X-Rays Diffraction (XRD) were recorded to obtain phase analysis and crystallite size determination. The crystallite size of Ag2O and CuO was 17.55 nm and 17.42 nm respectively. The spectral data obtained from Fourier Transform Infrared Spectroscopy (FTIR) analysis were also in agreement with the literature that ensured the formation of metal oxides. The Tauc plots were drawn to calculate the band gap energies, demonstrating that the nanocomposite formation caused several changes in electronic structure suitable for photocatalysis under solar light. The value of bandgap energy of nanocomposite was 1.51 eV which is less than pristine metal oxides such as CuO (2.77 eV) and Ag2O (1.61 eV). The percentage degradation of methylene blue, rhodamine B and benzoic acid using nanocomposite was 97.5%, 90.5% and 95%, which is far better than that of pure metal oxides. The results demonstrated that the as-synthesized nanocomposite has tremendous potential to degrade the toxic pollutants in minimum time duration.

Effect of Pretreatment on the Mechanical Properties of Orange Peel Particulate (Bio-Waste)-Reinforced Epoxy Composites

Effects of chemical treatments with benzoyl chloride, acetone and alkali on the physical and mechanical properties of Orange Peel Particulate (OPP) reinforced epoxy composite materials have been studied. Hand lay-up technique was applied to manufacture the composites. The experimental results illustrate that chemical treatment with benzoyl chloride has a considerable impact. The properties of OPP reinforced composite material have been enhanced by 15% (for tensile test) and 30% (in case of flexural test) due to benzoyl chloride treatment as compared to raw OPP composites. It is evident from Fourier Transform Infrared Spectroscopy (FTIR) that non cellulosic content was removed from the surface of the fiber due to benzoyl chloride treatment. After chemical treatment there was good interfacial bonding between matrix and filler material as observed in SEM micrographs. From the experimental observations, it can be seen that among all fabricated composites, set of composites with 30% filler loading yields excellent mechanical properties.

Forensic soil provenancing in an urban/suburban setting: A simultaneous multivariate approach.

Soil is a ubiquitous material at the Earth's surface with potential to be a useful evidence class in forensic and intelligence applications. Compositional data from a soil survey over North Canberra, Australian Capital Territory, are used to develop and test an empirical soil provenancing method. Mineralogical data from Fourier Transform InfraRed spectroscopy (FTIR) and geochemical data from X‐Ray Fluorescence (XRF; for total major oxides) and Inductively Coupled Plasma‐Mass Spectrometry (ICP‐MS; for both total and aqua regia‐soluble trace elements) are obtained from the survey's 268 topsoil samples (0–5 cm depth; 1 sample per km2). The simultaneous provenancing approach is underpinned by (i) the calculation of Spearman's correlation coefficients (rS ) between an evidentiary sample and all the samples in the database for all variables generated by each analytical method; and (ii) the preparation of an interpolated raster grid of rS for each evidentiary sample and method resulting in a series of provenance rasters (“heat maps”). The simultaneous provenancing method is tested on the North Canberra soil survey with three “blind” samples representing simulated evidentiary samples. Performance metrics of precision and accuracy indicate that the FTIR (mineralogy) and XRF (geochemistry) analytical methods offer the most precise and accurate provenance predictions. Maximizing the number of analytes/analytical techniques is advantageous in soil provenancing. Despite acknowledged limitations, it is concluded that the empirical soil provenancing approach can play an important role in forensic and intelligence applications.