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This paper aims to investigate the efficacy of grape pomace extract (GPE) as an eco-friendly vapor phase green inhibitor for corrosion of steel and assess the effect of the major compounds of extract on the inhibition efficiency.

The present study was carried out to identify the components present in the 2-propanol GPE by gas chromatography–mass spectrometry (GC-MS) analysis. Gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization, scanning electron microscopy and FTIR techniques were used to study the corrosion inhibitive.

GPE has inhibited mild steel corrosion in conditions of periodic condensation of moisture. The gravimetric measurement indicates that inhibition efficiency shows direct proportional relation with concentration of inhibitor. The GPE and main components acted as a mixed-type inhibitor with predominant cathodic effectiveness. Research limitations/implications. Because of the presence of large number of compounds in the extract, it becomes difficult to understand the most active compound responsible for inhibition. However, from gas chromatography, mass spectrometry and quantum data, the assumption has been made that the major compound of GPE is responsible for the inhibition activity.

The extract can be used in the temporary corrosion protection and is designed to prevent the corrosion of metal surfaces of equipment during transportation and storage.

GPE can be used as a potential source of ecofriendly corrosion inhibitor for steel corrosion.

Aromatic polyimides, polyamides and polyamide‐imides, as well as imide monomers, have been subjected to the alkali fusion technique of Schleuter and Siggia (164) using molten potassium hydroxide reagent. The volatile reaction products were concentrated in a cold trap as previously mentioned (c.f. alkyd resins and polyesters) prior to separation via GC. The identity of the monomer/polymer was determined from a study of the amine or diamine fragmentation products obtained, whilst the amount of each compound thus identified served as the basis for quantitative work. The isomeric 2,2′‐, 2,4′‐ and 4,4′‐ oligomers of diaminophenylmethane in aniline‐formaldehyde copolymers were identified individually by GC using 10% SE30 deposited on Chromaton N‐AW‐DMCS according to Krasnova et al (111).

The purposes of this study were to analyze fruits, vegetables, water and soil for organochlorine pesticide (OCP) residues and to assess the food exposure of these pesticides in Qatar.

Pesticides were quantified in dates, leafy vegetables, fruiting vegetables, water and soil samples using a gas chromatography-electron capture detector and gas chromatography-mass spectrometry. These pesticides were α-benzene hexachloride (BHC), ß-BHC, heptachlor, aldrin, g-chlordane, endosulfan I, α-chlordane, dieldrin, endrin and methoxychlor. Additionally, food exposure risk assessment was performed by estimating daily intakes of OCP.

Most analyzed samples contained at least one OCP residue. Endosulfan was the only pesticide that was not detected. The concentrations of OCP in samples were below the maximum residue level (MRL) except endosulfan. Among all the samples analyzed, ˜18% of those exceeded the MRL with respect to the concentrations of methoxychlor and heptachlor. Only intake of methoxychlor (0.018 mg/day) exceeded the MRL (0.01 mg/day). Dates and fruiting vegetables were likely to pose a higher risk than leafy vegetables because they contained heptachlor, endrin and methoxychlor. Leafy vegetables might pose a greater risk than dates and fruiting vegetables because of the presence of β-BHC and dieldrin.

Eight out of ten OCPs that were measured were found to be below the MRL. These pesticides should be eliminated from the food supply based on the Qatar National Implementation Plan of the Stockholm Convention in 2010. Based on the intake risk assessment, overall, the intake of OCP may not pose a major risk to human health as the concentrations of OCP were below MRL, except methoxychlor. Water and soil are the potential sources of contamination of OCP in foods that were tested in Qatar. To limit the health risks associated with OCPs, there is a need for close monitoring of food and agricultural practices and the types of pesticides imported into Qatar.

Because of the continuing usage of nitrocellulose lacquers, a study of the thinners to determine the percentages of the components is very important. Usually these thinners consist of a mixture aromatic and alphatic hydrocarbons (as diluents or non solvents) and ketones, esters and ethers (as solvents).

This paper aims to study the mass loss of three-dimensional (3D) printed materials at high temperatures. A preconcentration and analysis technique, static headspace gas chromatography-mass spectrometry (SHS-GC-MS), is demonstrated for the analysis of volatile compounds liberated from fused deposition modeling (FDM) and stereolithography (SLA) 3D printed models under elevated temperatures.

A total of seven commercial 3D printing materials were tested using the SHS-GC-MS approach. The printed model mass and mass loss were examined as a function of FDM printing parameters including printcore temperature, model size and printing speed, and the use of SLA postprocessing procedures. A high temperature resin was used to demonstrate that thermal degradation products can be identified when the model is incubated under high temperatures.

At higher printing temperatures and larger model sizes, the initial printed model mass increased and showed more significant mass loss after thermal incubation for FDM models. For models produced by SLA, the implementation of a postprocessing procedure reduced the mass loss at elevated temperatures. All FDM models showed severe structural deformation when exposed to high temperatures, while SLA models remained structurally intact. Mass spectra and chromatographic retention times acquired from the high temperature resin facilitated identification of eight compounds (monomers, crosslinkers and several photoinitiators) liberated from the resin.

The study exploits the high sensitivity of SHS-GC-MS to identify thermal degradation products emitted from 3D printed models under elevated temperatures. The results will aid in choosing appropriate filament/resin materials and printing mechanisms for applications that require elevated temperatures.

The aim of this study was to prepare antibacterial capsules and transfer them to cotton fabrics using the impregnation method.

For this purpose, helichrysum oil was encapsulated by ß-cyclodextrin (ß-CD) using the kneading method at three different molar ratios. The products were then applied to 100% cotton fabric through the impregnation method.

Morphological assessment showed that the inclusion complex had smooth surfaces and spherical shapes. Fourier transform infrared spectroscopy and differential scanning calorimeter analysis results confirmed the formation of the inclusion complex between ß-CD and the active agent at mole ratios of 1:1, 1:2 and 1:3 for helichrysum oil. According to the analyses, it was determined that the highest complexing rate was between 9.72% and 1:2 in capsules containing ß-CD:helichrysum oil and the sizes of particles which is 1:2 are determined to be between 2 and 25 µm. The presence of capsules on the fabrics was determined after 5 washing cycles. Antibacterial activity was evaluated against Staphylococcus aureus and Escherichia coli bacteria. The antibacterial analysis results showed that the inclusion complex provided a reduction of over 96% against both S. aureus and E. coli bacteria, and the fabrics exhibited antibacterial effects even after 5 washing cycles. The major constituents of the oil were decreased after 5 washes, but significant peaks were remained according to the gas chromatography analyses. These results indicate that helichrysum oil can be used for its antibacterial properties, and it has been observed that this activity continues up to 5 washes when transferred to the fabric in the form of an inclusion complex.

Although helichrysum oil is widely used in cosmetics, there is a lack of studies on its application in textiles. Therefore, this study investigated the potential use of helichrysum oil, which has a wide range of applications, in textiles for its antibacterial properties through molecular encapsulation. The use of naturally sourced substances such as helichrysum oil in the textile industry can offer an environmental and sustainable alternative. This study can be considered as a step toward the development of innovative and naturally sourced antibacterial products in the textile industry.

The purpose of this study is to investigate starch mucor (SM) in potassium iodide (KI) as corrosion inhibitor of aluminium in hydrochloric acid (HCl) medium.

The SM in KI was characterized by gravimetric, scanning electron microscopy, electrochemical impedance spectroscopy measurements, potentiodynamic polarization and gas chromatography-mass spectrometer techniques. The inhibition efficiency was optimized using response surface methodology.

The result revealed that the inhibitor inhibited corrosion at a low concentration with the rate of inhibition increasing as the concentration of the inhibitor increased. The inhibition efficiency increases as the temperature was increased with slight incorporation of the inhibitor (SM in KI). This indicates that the corrosion control is both inhibitor (SM in KI) and temperature dependent.

The research results can provide the basis for using SM in KI as corrosion inhibitor of aluminium in HCL medium. Mixed-type inhibitor nature of SM was proved by cathodic and anodic nature of the polarization curves.

Within the framework of the valorization of natural resources, a characterization of the biochemical composition of the edible parts of Adansonia Digitata is applied. The antibacterial effect against bacteria is also realized and compared to some synthetic antibiotics.

The biochemical characterization is carried out according to the norms of the French Association of Normalization, methods of Association of Official Analytical Chemists (AOAC International) and gas chromatography (GC). The antibacterial activity is tested by disk diffusion on a solid medium. Parametric tests are used to compare the differences between groups and heat maps to show the expression of the mean inhibitions according to the studied parameters. Multivariate logistic modeling is applied to study the effect of extracts and antibiotics on bacteria.

Biochemical characterization showed a variable importance of proteins, fibers and total sugars, with the presence of highly desired fatty acids such as palmitic, oleic, stearic, linoleic and a-linolenic acids. This gives the tested parts important energy values, especially in the seeds very rich in fatty acids. Methanol proved to be a better extraction solvent than dichloromethane. Antibacterial activity showed that pulp and leaves extracted with methanol had quite similar inhibitory activities against Enterococcus faecalis ATCC29212 and that this effect was better than some antibiotics. Multivariate analysis showed that the leaves had a similar effect to antibiotics, and a significant effect against Staphylococcus aureus ATCC29213.

This important activity and the attractive nutritional value of this plant could justify its extensive use in the traditional pharmacopoeia.

The purpose of this paper is to investigate the inhibitive properties of black pepper extract (BPE) for aluminium in 1M hydrochloric acid (HCl) medium.

Gravimetric, electrochemical impedance spectroscopy, galvanostatic polarization, scanning electron microscopy with energy dispersive X-ray examinations (SEM-EDX) techniques were used to study the corrosion inhibitive study.

The gravimetric measurement indicates that inhibition efficiency shows direct proportional relation with concentration of inhibitor. The impedance results illustrates that there was a presence of protective layer of inhibitor adsorbed on the metal/solution interface. Polarization outcome showed that BPE is mixed type inhibitor. The existence of adherent layer of inhibitor on the Al surface was confirmed by SEM-EDX. Quantum chemical calculations were performed using the density functional theory at B3LYP/6-31G(d) level of theory to evaluate the activity of inhibitor molecules present in extract towards the corrosion inhibition of Al.

Due to the presence of large number of compounds in the extract, it becomes difficult to understand the most active compound responsible for inhibition. However, from gas chromatography mass spectrometry and quantum data, the approximation has been made that the major compound piperine present in the extract can be most probable component responsible for the inhibition activity. Further calculation of binding energy between Al and inhibitor molecules can be performed using Material Studio software.

The extract can be used in cleaning and etching solutions. It can be used to limit the loss of Al metal during etching process.

BPE can be used as a potential source of eco-friendly corrosion inhibitor for Al in HCl medium.

The process of manufacturing an activated carbon nonwoven made by cotton fiber was investigated. The study was focused on cotton nonwoven formation, carbonization, activation, and characterization of the activated carbon nonwoven. Pyrolysis of the cotton carbonization was analyzed using TGA. There was a considerable decrease in weight loss in the region between 250°C to 400°C and the proper carbonized temperature was 400°C. The SEM examination indicated that the surface area of cotton fiber was increased significantly because the inside hollow of cotton fiber was widely opened and some small agglomerated particles were gasified after activation. Absorbability of the activated carbon nonwoven was evaluated using an instrument of inverse gas chromatography. Dispersive surface energy, specific free energy, and total surface energy all indicated this trend: Carbonized Cotton > Activated Cotton > Raw Cotton. The activated carbon nonwoven exhibited the potential for use as high adsorbent and absorbent materials. They are light weight and bulky, advantageous in protective clothing applications and other consumer and industrial applications.