Mohammadreza Johari, Masoud Rajabi and Vahid Mohammadi
The present paper aims to synthesize SrAl2O4:Eu2+, Dy3+ green-emitting phosphor nano-pigment powder using a combination of citrate – gel processing and microwave-assisted heating…
Abstract
Purpose
The present paper aims to synthesize SrAl2O4:Eu2+, Dy3+ green-emitting phosphor nano-pigment powder using a combination of citrate – gel processing and microwave-assisted heating route.
Design/methodology/approach
Microwave-assisted citrate – gel processing of SrAl2O4:Eu2+, Dy3+ green-emitting phosphor nano-pigment powder has been carried out by varying the pH and the molar ratio of H3Cit/Al3+ + Sr2+ +Eu2++Dy3+ (f/o). X-ray diffraction analysis showed that the produced powders were nearly pure SrAl2O4 phase, in which the SrAl2O4 host phase has the maximum fraction of green-emitting monoclinic SrAl2O4 phase.
Findings
Spectrophotometer results revealed that two excitation peaks appeared at 238 and 339 nm and an emission peak at 515 nm. The crystallite size of the green-emitting phosphor nano-pigment powder was about 37 nm as determined by Scherrer’s formula. The best conditions for formation of monoclinic SrAl2O4 phase with high purity were achieved at pH of precursor solution equal to 7 and the molar ratio of f/o equal to 3.
Originality/value
The present research work for the first time (to the best of the authors’ knowledge) has used microwave and sol–gel combination techniques to produce green-emitting phosphor nano-pigment powder (without using any other heating system).
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Vahideh Tajer Kajinebaf, Fereshteh Rezaeian, Masoud Rajabi and Saeid Baghshahi
– Replacing nano-clay for kaolin in ultramarine pigments was investigated. The paper aims to discuss these issues.
Abstract
Purpose
Replacing nano-clay for kaolin in ultramarine pigments was investigated. The paper aims to discuss these issues.
Design/methodology/approach
Ultramarine pigments with both kaolin and nano-clay were synthesized by traditional method. For this purpose, mixing of the raw materials consisted of calcined clay, sulfur, sodium hydroxide and Arabic gum was milled and then calcined at 800°C for 9 h under controlled atmosphere. The characterization was carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), UV-vis spectroscopy, colorimetery (CIELab method) and dynamic light scattering (DLS) techniques.
Findings
The investigations show that using nano-clay results in richer pigments. XRD results reveal that the ultramarine phase formation is enhanced by using nano-clay. SEM and DLS results also confirm that the ultramarine pigment synthesized by using nano-clay has smaller particles than that prepared by kaolin.
Originality/value
In this research, for the first time, nano-clay was substituted for kaolin to synthesized ultramarine pigment.
Mohammad Zamani, Zahra Sohrabi, Ladan Aghakhani, Kimia Leilami, Saeed Nosratabadi, Zahra Namkhah, Cain Clark, Neda Haghighat, Omid Asbaghi and Fatemeh Fathi
Previous research indicates that vitamin D and omega-3 co-supplementation may benefit overall health, but current evidence regarding its effects on lipid profile remains unclear…
Abstract
Purpose
Previous research indicates that vitamin D and omega-3 co-supplementation may benefit overall health, but current evidence regarding its effects on lipid profile remains unclear. The present systematic review and meta-analysis aimed to examine the effects of vitamin D and omega-3 co-supplementation on lipid profile (total cholesterol [TC], low-density lipoprotein [LDL], triglyceride [TG] and high-density lipoprotein [HDL]) in adults.
Design/methodology/approach
In this systematic review and meta-analysis, relevant studies were obtained by searching the PubMed, Scopus and Web of Science databases (from inception to January 2022). Weighted mean differences and 95% confidence intervals were estimated via a random-effects model. Heterogeneity, sensitivity analysis and publication bias were reported using standard methods.
Findings
Pooled analysis of six randomized controlled trials (RCTs) revealed that vitamin D and omega-3 co-supplementation yielded significant reductions in TG (p = 0.631). A pooled analysis of five trials indicated a significant association between omega-3 and vitamin D treatment and reductions in TC (p = 0.001) and LDL (p = 0.001). Although, pooled analyses of omega-3 and vitamin D did not significantly affect HDL.
Originality/value
The findings suggest that vitamin D and omega-3 co-supplementation lowers TG, TC and LDL in adults. Future, large-scale, RCTs on various populations are needed to elucidate further beneficial effects of vitamin D and omega-3 co-supplementation on lipid profile and establish guidelines for clinical practice.