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Article
Publication date: 19 October 2022

Fatimah A.M. Al-Zahrani

This paper aims to prepare a new donor–π–acceptor (D–π–A) and acceptor–π– D–π–A (A–π–D–π–A) phenothiazine (PTZ) in conjugation with vinyl isophorone (PTZ-1 and PTZ-2) were…

148

Abstract

Purpose

This paper aims to prepare a new donor–π–acceptor (D–π–A) and acceptor–π– D–π–A (A–π–D–π–A) phenothiazine (PTZ) in conjugation with vinyl isophorone (PTZ-1 and PTZ-2) were designed and their molecular shape, electrical structures and characteristics have been explored using the density functional theory (DFT). The results satisfactorily explain that the higher conjugative effect resulted in a smaller high occupied molecular orbital–lowest unoccupied molecular orbital gap (Eg). Both compounds show intramolecular charge transfer (ICT) transitions in the ultraviolet (UV)–visible range, with a bathochromic shift and higher absorption oscillator strength, as determined by DFT calculations.

Design/methodology/approach

The produced PTZ-1 and PTZ-2 sensors were characterized using various spectroscopic methods, including Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (1H/13CNMR). UV–visible absorbance spectra of the generated D–π–A PTZ-1 and A–π–D–π–A PTZ-2 dyes were explored in different solvents of changeable polarities to illustrate positive solvatochromism correlated to intramolecular charge transfer.

Findings

The emission spectra of PTZ-1 and PTZ-2 showed strong solvent-dependent band intensity and wavelength. Stokes shifts were monitored to increase with the increase of the solvent polarity up to 4122 cm−1 for the most polar solvent. Linear energy-solvation relationship was applied to inspect solvent-dependent Stokes shifting. Quantum yield (ф) of PTZ-1 and PTZ-2 was also explored. The maximum UV–visible absorbance wavelengths were detected at 417 and 419 nm, whereas the fluorescence intensity was monitored at 586 and 588 nm.

Originality/value

The PTZ-1 and PTZ-2 dyes leading to colorimetric and emission spectral changes together with a color shift from yellow to red.

Details

Pigment & Resin Technology, vol. 53 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 10 December 2024

Chanyoung Kim, Hye Eun Sim and Sang Jeen Hong

Semiconductor fabrication facilities often suffer from undesired particle introduction into process chambers in vacuum systems. Ideally, it is unusual to observe particles formed…

16

Abstract

Purpose

Semiconductor fabrication facilities often suffer from undesired particle introduction into process chambers in vacuum systems. Ideally, it is unusual to observe particles formed in the exhaust pumping line inside the chamber, but non-volatile compound products at relatively low temperatures jeopardize the vacuum pumping system, gas scrubber and the wafer-in-process. This study proposes a monitoring system for constructing a complete condition-based maintenance system for diagnosing the powder build-up within exhaust pipes used in the semiconductor manufacturing industry. This system includes ultrasonic sensors and machine learning.

Design/methodology/approach

Employing ultrasonic sensors, physical and data-driven models are established. The time- or frequency-domain data acquired by the monitoring system are converted into cepstrums for modeling the powder layer thickness using machine learning.

Findings

The algorithms used in the proposed system successfully classified the thicknesses with an average accuracy of above 97%, and feature importance analysis identified the quefrency that varied with the thickness of the powder layer.

Practical implications

The limitation of this research lies within the lab environment. It is unfortunate that the suggested method has not been evaluated in actual semiconductor manufacturing facilities, as powder build-up may take more than a few months to be called the facility maintenance. However, the submitted paper is still valid in academic and engineering aspects to be utilized in industry.

Originality/value

We modeled the system using data acquired by an ultrasonic sensor, and we constructed a data-driven model that was trained using cepstral data to replace the physical models that monitor thickness. We are the first to use ultrasound and machine learning to estimate the thickness of powder in the exhaust vacuum pumping line.

Details

Journal of Quality in Maintenance Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 20 May 2024

Shengjian Zhang, Min Li, Baoyi Li, Hansen Zhao and Feng Wang

To improve the corrosion resistance of magnesium alloys, the construction of protective coatings is necessary to extend the service life of Mg-based materials.

63

Abstract

Purpose

To improve the corrosion resistance of magnesium alloys, the construction of protective coatings is necessary to extend the service life of Mg-based materials.

Design/methodology/approach

SiO2 nanoparticles modified by dodecyltrimethoxysilane (DTMS) were added to the PP and a superhydrophobic Mg(OH)2/PP-60mSiO2 composite coating was fabricated on the surface of AZ31 magnesium alloy via the hydrothermal method and subsequently the immersion treatment.

Findings

Hydrophilic SiO2 nanoparticles become hydrophobic after modified by DTMS, showing a higher dispersibility in xylene. By incorporating modified SiO2 nanoparticles into the composite PP coating, the hydrophobicity of the layer was enhanced, resulting in a contact angle of 166.3° and a sliding angle of 3.4°. It also improved the water repellency and durability of the coating. Furthermore, the intermediate layer of Mg(OH)2 significantly strengthened the bond between the PP layer and the substrate. The Mg(OH)2/PP-60mSiO2 composite coating significantly enhances the corrosion resistance of the magnesium alloy by effectively blocking the infiltration of the corrosion anions during corrosion. The corrosion current density of the Mg(OH)2/PP-60mSiO2 composite coating is approximately 8.23 × 10–9 A·cm-2, which can achieve a magnitude three times lower than its substrate, making it a promising surface modification for the Mg alloy.

Originality/value

The composite coating effectively and durably enhances the corrosion resistance of magnesium alloys.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 11 July 2023

Gina Myers and Christopher Kowal

Violence toward frontline health-care workers (HCWs) from patients and visitors is a pervasive issue that ranges from verbal and psychological abuse to physical assault. The…

164

Abstract

Purpose

Violence toward frontline health-care workers (HCWs) from patients and visitors is a pervasive issue that ranges from verbal and psychological abuse to physical assault. The emergence of the COVID-19 pandemic has led to increased reports of escalated verbal workplace aggressions (VWPAs); however, most studies have been conducted internationally. Studies based in the USA have focused on physical violence experienced by nurses and paramedics in emergency situations. The purpose of this study is to learn about the experiences of different levels of frontline HCWs with VWPA from patients and visitors and discover ways to address this issue.

Design/methodology/approach

This qualitative descriptive study asked registered nurses, licensed practical nurses and patient care technicians from one health-care system about their experiences with patient and visitor VWPA using an anonymous, voluntary open-ended survey and in-person interviews. In all, 31 participants completed the survey and 2 were interviewed. Data were analyzed using content analysis.

Findings

Three themes emerged from the data: the experience, moving through and moving forward. Frontline HCWs described experiences of VWPA, indicating its forms, frequency and conditions. They used coping, along with personal and professional measures, to manage and move through the situation. Moving forward was captured as suggestions for the future and conveyed hope for a perfect state.

Originality/value

The experiences of frontline HCWs offered insight into how they perceive and cope with difficult encounters. Recommendations relate to not only implementing interventions that support frontline HCWs but also creating a culture where aggression is not tolerated and addressing perpetrator behavior is a priority.

Details

Journal of Aggression, Conflict and Peace Research, vol. 16 no. 2
Type: Research Article
ISSN: 1759-6599

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Article
Publication date: 8 September 2022

Asieh Yahyazadeh, Enayatollah Moradi Rufchahi, Hessamoddin Yousefi and Seyyedeh Maryam Golzar Poursadeghi

This paper aims to synthesize 6-ethyl-4-hydroxyquinolin-2(1H)-one as a new enol-type coupling component in the preparation of some 3-arylazo-4-hydroxyquinolin-2(1H)-one dyes and…

110

Abstract

Purpose

This paper aims to synthesize 6-ethyl-4-hydroxyquinolin-2(1H)-one as a new enol-type coupling component in the preparation of some 3-arylazo-4-hydroxyquinolin-2(1H)-one dyes and evaluate the solvent effects on their absorption in ultraviolet-visible spectra.

Design/methodology/approach

6-Ethyl-4-hydroxyquinolin-2(1H)-one was synthesized by thermal cyclocondensation reaction of N, N′-bis(4-ethylphenyl) malonamide at 130–140°C in polyphosphoric acid. This compound was then applied in the azo-coupling reaction with some aniline-based diazonium salts, so as to prepare seven new mono-heterocyclic azo dyes. The structures of the compounds were confirmed using mass spectroscopic technique. Fourier transform infra red (FT-IR) and 1H proton nuclear magnetic resonance (1H NMR) and carbon-13 nuclear magnetic resonance (13 C NMR) studies on the structure of the azo compounds revealed that they exist as two E- and Z-isomers of hydrazone tautomer both in solid and solution state. The effects of acid and base on the visible absorption spectra of the dyes were also evaluated and discussed.

Findings

Ultra violet-visible UV-vis absorption spectra of the dyes didn’t show significant variation by changing of solvents because of intramolecular H-bonding between proposed hydrazone forms and 2- and 4-keto functions in their structures. The spectra of the dyes were not sensitive to the addition of acid but were very sensitive to base.

Originality/value

The synthesized 3-arylazo-4-hydroxyquinolin-2(1H)-one dyes are new members in the 4-hydroxyquinolin-2(1H)-one azo dyes family, where very few details regarding the synthesis of such dyes are reported before in the literature. They are unique in terms of synthesis and spectral properties.

Details

Pigment & Resin Technology, vol. 53 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 23 August 2023

Pankaj Naharwal, Mahesh Meena, Charul Somani, Neetu Kumari and Dinesh Kumar Yadav

This paper aims to critically review the isolation and chemistry of plant pigments.

123

Abstract

Purpose

This paper aims to critically review the isolation and chemistry of plant pigments.

Design/methodology/approach

A literature survey from 1974 to 2022 was carried out and studied thoroughly. The authors reviewed literature in various areas such as isolation methods and catalytic properties of pigments.

Findings

With vast growing research in the field of catalytic activities of various pigments like chlorophyll, anthocyanin and flavonoids, there is still scope for further research for the pigments such as Lycopene, carotenoids and xanthophyll as there has not been any significant work in this area.

Research limitations/implications

Plant pigments may be used as an ecofriendly catalyst for chemical reactions.

Practical implications

One can get the direction of pigment research.

Social implications

Plant pigments are natural and ecofriendly catalyst which can reduce the pollution.

Originality/value

This is an original work. This paper precisely depicts the advantages as well as disadvantages of the isolation techniques of pigments. This study also presents the chemistry of plant pigments.

Graphical abstract

Details

Pigment & Resin Technology, vol. 53 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 3 May 2024

Hui Zhao, Shunzhen Ren, Zhengbo Zhong, Zhipeng Li and Tianhui Ren

This study aims to reveal the tribological mechanism of synergistic effect between MoDTC and P-containing additives in aluminum-based grease.

82

Abstract

Purpose

This study aims to reveal the tribological mechanism of synergistic effect between MoDTC and P-containing additives in aluminum-based grease.

Design/methodology/approach

The authors prepared a molybdenum dialkyl dithiocarbamate (MoDTC) and revealed the tribological mechanism of synergistic effect between MoDTC and P-containing additives in aluminum-based grease by combining with ZDDP and P-containing and S-free additives.

Findings

The MoDTC the authors prepared has good friction-reducing and anti-wear properties in aluminum-based grease and has an obvious synergistic effect with ZDDP. MoDTC and ZDDP have a significant synergistic effect on the tribological properties in aluminum-based grease, mainly because of the formation of phosphates and metaphosphates as well as more MoS2 in the friction film. P element plays a facilitating role in the chemical conversion of MoDTC to MoS2.

Originality/value

The experiments of MoDTC with tributyl phosphate and trimethylphenyl phosphate confirm that the P element plays a facilitating role in the chemical conversion of MoDTC into MoS2.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2023-0410

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 27 February 2023

Ali A. Ali, H. Abd El-Wahab, Moustafa S. Abusaif, Ahmed Ragab, Omar A. Abdel-Jaid, E.A. Eldeeb and Yousry A. Ammar

The paper aims to the preparation of novel disperse dye based on azo salicylaldehyde derivatives TF-A [2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde] and full…

206

Abstract

Purpose

The paper aims to the preparation of novel disperse dye based on azo salicylaldehyde derivatives TF-A [2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde] and full evaluation of their use as disperse dye TF-ASC [bis 2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde Schiff base with 4,4'-methylenedianiline] for dyeing polyester fabric at various conditions.

Design/methodology/approach

The dispersed dye was synthesized via Schiff base condensation in the presence of ceric ammonium nitrate cerium ammonium nitrate 10 mmole% as an eco-friendly catalyst at room temperature. The chemical structure of the prepared dye was characterized via elemental analysis, Fourier-transform infrared spectroscopy, 1H- and 13 C-NMR spectroscopic analysis tools. This study thoroughly examined the dyeing of disperse dye TF-ASC on polyester at various conditions. The characteristics of dyed polyester fabric were measured by colour measurements, as well as light, washing, crock fastness and finally, colour strength. The discrete fourier transform (DFT) theoretical studies, including EHOMO, ELUMO and optimized geometrical structure, were assumed and discussed in detail.

Findings

The results showed that the synthesized organic dye TF-ASC was highly functional and appropriate for this kind of dyeing method. The dyeing fabrics obtained from disperse dye TF-ASC, properties possess high colour strength as well as good overall fastness properties. These dyes had a high affinity for polyester fabric, with just a tiny change in dye affinity when the pH was changed, even under alkaline circumstances. The dye levelness and shade depth of the colour results were good, and there were a variety of hues from light brownish yellow to deep brownish yellow. The results obtained from DFT computational studies such as EHOMO, ELUMO, optimized structure, diploe moment µ and electrophilicity index deduced that prepared organic dye TF-ASC is more applicable as a dispersed dye.

Originality/value

This research is significant because it provides a new dye for dyeing polyethylene terephthalate fibres with exceptional brightness and levelness; the method of preparation is a useful pathway due to its being known as a green chemistry method.

Details

Pigment & Resin Technology, vol. 53 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 9 May 2023

Jing Chen, Hongli Chen and Yingyun Li

Cross-app interactive search has become the new normal, but the characteristics of their tactic transitions are still unclear. This study investigated the transitions of daily…

174

Abstract

Purpose

Cross-app interactive search has become the new normal, but the characteristics of their tactic transitions are still unclear. This study investigated the transitions of daily search tactics during the cross-app interaction search process.

Design/methodology/approach

In total, 204 young participants' impressive cross-app search experiences in real daily situations were collected. The search tactics and tactic transition sequences in their search process were obtained by open coding. Statistical analysis and sequence analysis were used to analyze the frequently applied tactics, the frequency and probability of tactic transitions and the tactic transition sequences representing characteristics of tactic transitions occurring at the beginning, middle and ending phases. 

Findings

Creating the search statement (Creat), evaluating search results (EvalR), evaluating an individual item (EvalI) and keeping a record (Rec) were the most frequently applied tactics. The frequency and probability of transitions differed significantly between different tactic types. “Creat? EvalR? EvalI? Rec” is the typical path; Initiate the search in various ways and modifying the search statement were highlighted at the beginning phase; iteratively creating the search statement is highlighted in the middle phase; Moreover, utilization and feedback of information are highlighted at the ending phase. 

Originality/value

The present study shed new light on tactic transitions in the cross-app interactive environment to explore information search behaviour. The findings of this work provide targeted suggestions for optimizing APP query, browsing and monitoring systems.

Details

Information Technology & People, vol. 37 no. 3
Type: Research Article
ISSN: 0959-3845

Keywords

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