Microwave Absorption Properties of Polyaniline/Poly(vinyl alcohol)/Multi-Walled Carbon Nanotube Composites in Thin Film and Nanofiber Layer Structures

Golestan Salimbeygi,Ahmad Mousavi Shoushtari,Komeil Nasouri,Reza Malek,Firoozmehr Mazaheri 한국고분자학회 2015 Macromolecular Research Vol.23 No.8

Electrospinning of conductive polymer blends offers high potential to prepare novel materials for electronical applications. The main aim of this work is to fabricate poly(vinyl alcohol) (PVA), polyaniline (PANI), and multi walled carbon nanotubes (MWNT) composites in thin film and nanofiber layer structures and then compare their microwave absorption behavior. First, optimum ratios for blending PVA, PANI, Camphorsulfonic acid (CSA) and MWNT were obtained. Then under optimized ratios, composite solutions of PVA: PANI-CSA, and PVA/PANI-CSA/ MWNT were fabricated to nanofiber layer and thin film structures. Based on scanning electron microscope (SEM) micrographs, the PVA/PANI-CSA nanofiber samples at low content of PANI-CSA presented a very uniform surface and without any beads but some beads started to develop at higher PANI-CSA content. However, the SEM analysis of the PVA/PANI-CSA/MWNT films revealed the uniform appearance for all composites. But, some aggregation and local irregularities on the surface were observed due to the presence of MWNT in the composite structure. Microwave absorption behavior was evaluated using vector network analyzers in the frequency range of 8-12 GHz (X-band) for all samples. It was observed that absorption microwave properties of PVA/PANI-CSA nanofibers improved with increasing in the loading levels of PANI-CSA in the mixture. Microwave absorption properties of the PVA/PANI-CSA/MWNT composite nanofiber absorbers have been compared with thin films at various thicknesses by measuring the relative maximum reflection loss (dB/mm) of samples. The PVA/PANI-CSA/MWNT composite nanofibers with the layer thickness of 0.1 mm presented two remarkable absorbing peaks versus one absorbing peak in nanocomposite films with similar thickness. The relative maximum reflection loss in PVA/PANI-CSA/MWNT composite nanofiber has reached -230 dB/mm at frequency of 8.6 GHz which is nearly 8 times higher than -28 dB/ mm at frequency of 8.4 GHz for PVA/PANI-CSA/MWNT film samples.

R- and Q-mode multivariate analysis to sense spatial mineralization rather than uni-elemental fractal modeling in polymetallic vein deposits

F. Darabi-Golestan,A. Hezarkhani 한국자원공학회 2018 Geosystem engineering Vol.21 No.4

Anomalous patterns from mineralizing processes are very complex associated with their spatial and frequency properties. Determination of how clustering elemental occurrences are and their spatial association within polymetallic veins deposit as a particular geological feature is critical issue for exploration. Fractal (as non-Euclidean geometries) models are uni-elemental and quantitative method, but R-mode and Q-mode analysis corresponding to multivariate techniques could ease quantitative and qualitative interpretations. The R-mode and Q-mode are the two main informative procedures in many multivariate analyses and are useful in order to handle quantitative and qualitative properties. The first and second Dimension of variation from the R-mode and Q-mode analysis explain 77% of the total variance of the polymetallic system at the area. The mineralization trend of Ag≈As≥Au>Pb>Te>Mo>Zn>S>W>Cu indicated from associated large Euclidean distances from R-mode, occurred due to polymetallic samples ID’s of 35, 33, 28, 29, 32, 34, 31, 30, 36, 81, 47 and 80 which resulted from Q-mode analysis. The combination of them is introduced by correspondence analysis (CA) intuitive graphical display to sense and respond to spatial heterogeneity of polymetallic vein deposit.

A New Synchronous Reference Frame-Based Method for Single-Phase Shunt Active Power Filters

Monfared, Mohammad,Golestan, Saeed,Guerrero, Josep M. The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.4

This paper discusses the design of a novel synchronous reference frame (SRF) method that can extract the reference compensating current for single-phase shunt active power filters (APFs). Unlike previous SRF studies, the proposed method has an innovative feature that does not require a fictitious current signal. Other key features of the proposed strategy include frequency-independent operation, accurate reference current extraction, and relatively fast transient response. The effectiveness of the proposed method is investigated by conducting a detailed mathematical analysis. Results of the analysis confirm the superior performance of the suggested approach. Theoretical evaluations are confirmed by the experimental results.

Assessment of the potential of algae phycobiliprotein nanoliposome for extending the shelf life of common carp burgers during refrigerated storage

Haghdoost, Amir,Golestan, Leila,Hasani, Maryam,Noghabi, Mostafa Shahidi,Shahidi, Seyed Ahmad The Korean Society of Fisheries and Aquatic Scienc 2022 Fisheries and Aquatic Sciences Vol.25 No.5

This study is focused on the effect of phycobiliprotein extraction of Gracilaria on the quality of common carp burgers, and the application of nanoliposomes containing pigment in the improvement of its antimicrobial and antioxidant activity of burgers during refrigerated storage in 18 days. Burgers were incorporated with phycobiliprotein and liposomal phycobiliprotein (2.5% and 5% w/w), and their chemical and microbial changes in terms of pH, peroxide value (PV), thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), total viable counts (TVC), psychrotrophic bacterial counts (PTC), and sensory characteristics were evaluated. Results presented a nanoliposome size of about 515.5 nm with capable encapsulation efficiency (83.98%). Our results showed non-encapsulated phycobiliprotein could delay the deterioration of common carp burgers, as a reduction in PV, TBA, and TVB-N, TVC, and PTC values in burgers treated with free and nano encapsulated phycobiliprotein. Moreover, the potential of phycobiliprotein was improved when it was encapsulated into chitosan coated liposomes. Burgers treated with 5% nanoliposomes displayed the lowest amount of lipid oxidation and microbial deterioration in comparison to others during storage. According to chemical, microbial and sensory evaluation, the shelf life of common carp burgers was increased in samples treated with encapsulated phycobiliprotein at 2.5% and 5%, as compared to the control (p ≤ 0.05).

A New Synchronous Reference Frame-Based Method for Single-Phase Shunt Active Power Filters

Mohammad Monfared,Saeed Golestan,Josep M. Guerrero 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.4

This paper discusses the design of a novel synchronous reference frame (SRF) method that can extract the reference compensating current for single-phase shunt active power filters (APFs). Unlike previous SRF studies, the proposed method has an innovative feature that does not require a fictitious current signal. Other key features of the proposed strategy include frequency-independent operation, accurate reference current extraction, and relatively fast transient response. The effectiveness of the proposed method is investigated by conducting a detailed mathematical analysis. Results of the analysis confirm the superior performance of the suggested approach. Theoretical evaluations are confirmed by the experimental results.

Transition nuclear protein 1 as a novel biomarker in patients with fertilization failure

Jamileh Sadat Mirsanei,Hadis Gholipour,Zahra Zandieh,Masoumeh Golestan Jahromi,Mojgan Javedani Masroor,Mehdi Mehdizadeh,Fatemehsadat Amjadi The Korean Society for Reproductive Medicine 2023 Clinical and Experimental Reproductive Medicine Vol.50 No.3

Objective: Although intracytoplasmic sperm injection (ICSI) is a way to deal with in vitro fertilization failure, 3% of couples still experience repeated fertilization failure after attempted ICSI, despite having sperm within normal parameters. These patients are a challenging group whose sperm cannot fertilize the egg during ICSI. Unfortunately, no test can predict the risk of fertilization failure. Phospholipase C zeta (PLCζ) and transition nuclear proteins (TNPs) are essential factors for chromatin packaging during sperm maturation. This study aimed to assess PLCζ1 and TNP1 expression in the sperm of patients with fertilization failure and the correlations among the DNA fragmentation index, PLCζ1 and TNP1 gene and protein expression, and the risk of fertilization failure. Methods: In this study, 12 infertile couples with low fertilization rates (<25%) and complete failure of fertilization in their prior ICSI cycles despite normal sperm parameters were chosen as the case group. Fifteen individuals who underwent ICSI for the first time served as the control group. After sperm analysis and DNA fragmentation assays, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blot analyses were performed to compare the gene and protein expression of PLCζ and TNP1 in both groups. Results: DNA fragmentation was significantly higher in the fertilization failure group. The qRT-PCR and Western blot results demonstrated significantly lower PLCζ and TNP1 gene and protein expression in these patients than in controls. Conclusion: The present study showed that fertilization failure in normozoospermic men was probably due to deficient DNA packaging and expression of TNP1.

TLR-1, TLR-2, and TLR-6 MYD88-dependent signaling pathway: A potential factor in the interaction of high-DNA fragmentation human sperm with fallopian tube epithelial cells

Zahra Zandieh,Azam Govahi,Azin Aghamajidi,Ehsan Raoufi,Fatemehsadat Amjadi,Samaneh Aghajanpour,Masoomeh Golestan,Reza Aflatoonian The Korean Society for Reproductive Medicine 2023 Clinical and Experimental Reproductive Medicine Vol.50 No.1

Objective: The DNA integrity of spermatozoa that attach to fallopian tube (FT) cells is higher than spermatozoa that do not attach. FT epithelial cells can distinguish normal and abnormal sperm chromatin. This study investigated the effects of sperm with a high-DNA fragmentation index (DFI) from men with unexplained repeated implantation failure (RIF) on the Toll-like receptor (TLR) signaling pathway in human FT cells in vitro. Methods: Ten men with a RIF history and high-DFI and 10 healthy donors with low-DFI comprised the high-DFI (>30%) and control (<30%) groups, respectively. After fresh semen preparation, sperm were co-cultured with a human FT epithelial cell line (OE-E6/E7) for 24 hours. RNA was extracted from the cell line and the human innate and adaptive immune responses were tested using an RT2 profiler polymerase chain reaction (PCR) array. Results: The PCR array data showed significantly higher TLR-1, TLR-2, TLR-3, TLR-6, interleukin 1α (IL-1α), IL-1β, IL-6, IL-12, interferon α (IFN-α), IFN-β, tumor necrosis factor α (TNF-α), CXCL8, GM-CSF, G-CSF, CD14, ELK1, IRAK1, IRAK2, IRAK4, IRF1, IRF3, LY96, MAP2K3, MAP2K4, MAP3K7, MAP4K4, MAPK8, MAPK8IP3, MYD88, NFKB1, NFKB2, REL, TIRAP, and TRAF6 expression in the high-DFI group than in the control group. These factors are all involved in the TLR-MyD88 signaling pathway. Conclusion: The MyD88-dependent pathway through TLR-1, TLR-2, and TLR-6 activation may be one of the main inflammatory pathways activated by high-DFI sperm from men with RIF. Following activation of this pathway, epithelial cells produce inflammatory cytokines, resulting in neutrophil infiltration, activation, phagocytosis, neutrophil extracellular trap formation, and apoptosis.