THE CLASSIFICATION OF A CLASS OF HOMOGENEOUS INTEGRAL TABLE ALGEBRAS OF DEGREE FIVE

Barghi, A.Rahnamai 한국전산응용수학회 2001 The Korean journal of computational & applied math Vol.8 No.1

The purpose of this paper is to give the classification of homogeneous integral table algebras of degree 5 containing a faithful real element of which 2. In fact, these algebras are classified to exact isomorphism, that is the sets of structure constants which arise from the given basis are completely determined. This is work towards classifying homogeneous integral table algebras of degree 5. AMS Mathematics Subject Classification : 20C05, 20C99.

Human exposure to HBCD and TBBPA via indoor dust in Korea: Estimation of external exposure and body burden

Barghi, Mandana,Shin, Eun-su,Kim, Jong-chul,Choi, Sung-Deuk,Chang, Yoon-Seok Elsevier 2017 Science of the Total Environment Vol. No.

<P><B>Abstract</B></P> <P>Human exposure to brominated flame retardants (BFRs) such as hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) mainly occurs through diet and dust ingestion. In this study, the BFR concentrations in 124 vacuum dust samples of six categories of indoor environments (homes, offices, kindergartens, cars, schools, and public indoor environments) and 32 surface dust samples were investigated. The median ΣHBCD concentrations ranged from 106.30ngg<SUP>−1</SUP> in home dust to 496.13ngg<SUP>−1</SUP> in office dust. The TBBPA concentrations in indoor dust (from 78.87 to 463.81ngg<SUP>−1</SUP>) were among the highest compared to other countries because of the high market demand for this flame retardant in Korea. The TBBPA concentrations in surface dust of living rooms were significantly higher (p<0.05) than sleeping rooms, due to the presence of more electrical equipment in living rooms. The estimated daily intakes (EDI) of ΣHBCD and TBBPA (dust+diet) for toddlers were 6.18ngkg<SUP>−1</SUP> bwd<SUP>−1</SUP> and 2.54ngkg<SUP>−1</SUP> bwd<SUP>−1</SUP>, respectively. In general, the ΣHBCD estimated body burden of Korean adults showed good agreement with the reported ΣHBCD median concentrations in their sera. Since the developmental health effect of exposure to HBCD was categorized as “high hazard” by the US Environmental Protection Agency, the estimated high body burden of ΣHBCD in Korean toddlers (7.91ngg<SUP>−1</SUP> lw) warns us of possible adverse effects on the development of essential systems in their bodies.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High concentrations of TBBPA were found in indoor dust in Korea. </LI> <LI> Food is the main contributor in ΣHBCD daily intake for Korean adults. </LI> <LI> The estimated ΣHBCD body burden of Korean toddlers was 7.91ngg<SUP>−1</SUP> lw. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Hexabromocyclododecane (HBCD) in the Korean food basket and estimation of dietary exposure

Barghi, M.,Shin, E.s.,Son, M.H.,Choi, S.D.,Pyo, H.,Chang, Y.S. Elsevier Applied Science Publishers 2016 Environmental pollution Vol.213 No.-

1,2,5,6,9,10-hexabromocyclododecane (HBCD) is a brominated flame retardant that is used worldwide in expanded and extruded polystyrene foam and simultaneously emitted to the environment. HBCD can easily accumulate in animals and humans and cause neurotoxicity, thyroid hormone disruption, and reproductive disorders. Therefore, it is essential to monitor the HBCD concentrations in foods and estimate the human exposure through the diet. In this study a total of 521 food samples from eight food categories were sampled and analyzed for their HBCD content. Based on consumption data, the average dietary intake of the general Korean population and specific subgroups was calculated. The highest levels of HBCD were found in fish and shellfish (0.47 ng g<SUP>-1</SUP> ww), and this was attributed to natural exposure to the contaminated marine environments and the HBCD bioaccumulation. In addition, the use of expanded polystyrene buoys in aquaculture was also found to be a potential source of HBCD in bivalves. The high solubility of α-HBCD in water and the persistence of this diastereomer compared to β- and γ-HBCD in biological tissues, led to higher accumulation of α-HBCD in animal-based foods. In contrast, the diastereomeric selectivity and lower metabolic capacity in plants compared with animals led to the predominance of γ-HBCD in plant-based foods. The dietary intake of HBCD was estimated to be 0.82 ng kg<SUP>-1</SUP> bw d<SUP>-1</SUP> in the general population and 2.89 ng kg<SUP>-1</SUP> bw d<SUP>-1</SUP> in children up to 5 years of age. The high HBCD intake in children was found to be a result of their lower body weight and their high consumption of milk and homemade Korean baby foods that usually contain fish.

HBCD and TBBPA in human scalp hair: Evidence of internal exposure

Barghi, Mandana,Shin, Eun-su,Choi, Sung-Deuk,Dahmardeh Behrooz, Reza,Chang, Yoon-Seok Elsevier 2018 CHEMOSPHERE - Vol.207 No.-

<P><B>Abstract</B></P> <P>Human biomonitoring is a reliable method for evaluating human exposure to specific contaminants. Although blood is an ideal matrix for monitoring purposes, it is regarded as an invasive matrix. Therefore, current developments in the field of human biomonitoring are based on introducing new methods that use non-invasive matrices, such as hair. In this study, we examined the efficiencies of several extraction methods for the analysis of hexabromocyclododecane (HBCD) and tetrabromobisphenol-A (TBBPA) in human hair. The selected pretreatment method was validated through a general QA/QC process that included spiking experiments, and then, the method was used for the determination of HBCD and TBBPA concentrations in scalp hair samples collected from individuals in Korea (n = 24) and Iran (n = 15). The HBCD and TBBPA concentrations in the collected hair samples ranged from ND to 3.24 ng g<SUP>−1</SUP> and ND to 16.04 ng g<SUP>−1</SUP>, respectively. Significantly higher concentrations of TBBPA were found in hair samples from Korea than those in hair samples from Iran (p < 0.05), which is expected to be the result of the large market and higher exposure of TBBPA in Korea. HBCD was not detected in hair samples from Iran. According to our knowledge this is the first study demonstrating the presence of TBBPA in human hair with nonspecific exposure. Lastly, we investigated the important factors that influence the interpretation of the contributions of endogenous and exogenous contaminations in hair. Based on the information, the HBCD and TBBPA in the collected hair samples were most likely from endogenous exposure. Therefore, our study showed that hair is potentially a suitable indicator for the monitoring of internal exposure to HBCD and TBBPA in different populations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The efficiencies of six extraction methods were examined for analysis of BFRs in human hair. </LI> <LI> TBBPA was found (for the first time) in human hair with nonspecific exposure. </LI> <LI> Higher concentrations of BFRs were found in hair samples from Korea compared to Iran. </LI> <LI> BFRs in the collected hair samples were most likely from endogenous exposure. </LI> <LI> Hair is a suitable indicator for monitoring BFR exposure in different populations. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Influence of non-detect data-handling on toxic equivalency quantities of PCDD/Fs and dioxin-like PCBs: A case study of major fish species purchased in Korea

Barghi, M.,Choi, S.D.,Kwon, H.O.,Lee, Y.S.,Chang, Y.S. Elsevier Applied Science Publishers 2016 Environmental pollution Vol.214 No.-

It has been known that substitution is not a suitable method to address non-detect (ND) data and can result in significant errors. However, reports of reliable statistical methods for handling ND data of polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in fish are rare. This work examines US-EPA's recommended statistical methods and traditional substitution-based methods for handling ND data in PCDD/F and DL-PCB datasets obtained from 240 fish samples. The Kaplan-Meier (KM) method was confirmed as a suitable statistical approach for dealing with our fish datasets. The results of the KM and substitution methods were compared; a significant difference was found in TEQs derived from KM and substitution for PCDD/Fs, suggesting that the handling of ND data is a critical issue for PCDD/Fs. For example, the substitution by ½LOD resulted in 20-25% overestimation of PCDD/F TEQs for fish samples with ND data (60-70%). In conclusion, the use of KM method is preferable for average TEQs, and if the use of KM is not applicable, substitution by zero is preferred. Based on this conclusion, the characteristics of fish contamination by PCDD/Fs and DL-PCBs in Korea were investigated.

Accumulation and exposure assessment of persistent chlorinated and fluorinated contaminants in Korean birds

Barghi, Mandana,Jin, Xiangzi,Lee, Sunggyu,Jeong, Yunsun,Yu, Jae-Pyoung,Paek, Woon-Kee,Moon, Hyo-Bang Elsevier 2018 Science of the Total Environment Vol.645 No.-

<P><B>Abstract</B></P> <P>To date, information is scarce on the accumulation and potential risks of persistent chlorinated and fluorinated contaminants in birds. In this study, organohalogen contaminants (OHCs), such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and perfluoroalkyl substances (PFASs), were measured in the liver tissues of 10 bird species (<I>n</I> = 69) from Korea. Among the OHCs, PFASs showed the highest concentration, ranging from 5.40 to 11,300 (median: 294) ng/g wet weight. The median concentrations of OCPs and PCBs in all the bird samples were 147 and 81.9 ng/g lipid weight, respectively. The maximum concentration of perfluorooctane sulfonate (PFOS) observed in our bird samples was highest reported so far. Concentrations of OHCs in predatory birds were significantly greater than those measured in non-predatory birds, indicating the importance of diet and trophic position for bioaccumulation of these contaminants. In addition, different accumulation patterns of OHCs were found between predatory and non-predatory birds. Significant correlations were found between organochlorine concentrations and stable nitrogen isotope ratio (δ<SUP>15</SUP>N) measurements, whereas no correlation was found between PFASs and δ<SUP>15</SUP>N. Although the concentrations of PCBs and DDTs in birds were lower than the threshold levels, 25% and 49% of birds exceeded the toxicity reference value and predicted no effect concentration for PFOS, respectively, implying potential health risks to Korean birds.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Concentrations of PCBs, OCPs, and PFASs varied in several bird species from Korea. </LI> <LI> PFOS concentration found was highest for a bird species on a global scale. </LI> <LI> Accumulation levels and profiles of OHCs varied by trophic position and migration pattern. </LI> <LI> Organochlorines biomagnified in residential predatory birds. </LI> <LI> PFOS concentrations in most of the predatory birds exceeded threshold values for adverse health effects. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis, Characterization and in vitro Anti-Tumoral Evaluation of Erlotinib-PCEC Nanoparticles

Barghi, Leila,Asgari, Davoud,Barar, Jaleh,Nakhlband, Aylar,Valizadeh, Hadi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: Development of a nanosized polymeric delivery system for erlotinib was the main objective of this research. Materials and Methods: Poly caprolactone-polyethylene glycol-polycaprolactone (PCEC) copolymers with different compositions were synthesized via ring opening polymerization. Formation of triblock copolymers was confirmed by HNMR as well as FT-IR. Erlotinib loaded nanoparticles were prepared by means of synthesized copolymers with solvent displacement method. Results: Physicochemical properties of obtained polymeric nanoparticles were dependent on composition of used copolymers. Size of particles was decreased with decreasing the PCL/PEG molar ratio in used copolymers. Encapsulation efficiency of prepared formulations was declined by decreasing their particle size. Drug release behavior from the prepared nanoparticles exhibited a sustained pattern without a burst release. From the release profiles, it can be found that erlotinib release rate from polymeric nanoparticles is decreased by increase of CL/PEG molar ratio of prepared block copolymers. Based on MTT assay results, cell growth inhibition of erlotinib has a dose and time dependent pattern. After 72 hours of exposure, the 50% inhibitory concentration (IC50) of erlotinib hydrochloride was appeared to be $14.8{\mu}M$. Conclusions: From the obtained results, it can be concluded that the prepared PCEC nanoparticles in this study might have the potential to be considered as delivery system for erlotinib.

Review of Multifunctional Inverter Topologies and Control Schemes Used in Distributed Generation Systems

Teke, Ahmet,Latran, Mohammad Barghi The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

Recent developments in power electronics technology have spurred interest in the use of renewable energy sources as distributed generation (DG) generators. The key component in DG generators is a grid-connected inverter that serves as an effective interface between the renewable energy source and the utility grid. The multifunctional inverter (MFI) is special type of grid-connected inverter that has elicited much attention in recent years. MFIs not only generate power for DGs but also provide increased functionality through improved power quality and voltage and reactive power support; thus, the capability of the auxiliary service for the utility grid is improved. This paper presents a comprehensive review of the various MFI system configurations for single-phase (two-wire) and three-phase (three- or four-wire) systems and control strategies for the compensation of different power quality problems. The advances in practical applications and recent research on MFIs are presented through a review of nearly 200 papers.

Spatial and temporal trends of PCDD/Fs in sediment and bivalves along the Korean coasts during 2001–2012

Kim, Eun-Kyo,Barghi, Mandana,Choi, Minkyu,Moon, Hyo-Bang PERGAMON 2019 MARINE POLLUTION BULLETIN Vol.146 No.-

<P><B>Abstract</B></P> <P>Concentrations of polychlorinated dibenzo-<I>para</I>-dioxins and dibenzofurans (PCDD/Fs) were measured in sediment and bivalves at 25 locations along the Korean coasts during 2001–2012. Concentrations of PCDD/Fs in sediment and bivalves ranged from 0.15 to 18.9 pg TEQ/g dry weight and from 0.06 to 7.70 pg TEQ/g wet weight, respectively. Elevated PCDD/F concentrations were found at locations close to largest industrial complexes and commercial harbors. A significant decreasing trend of PCDD/Fs in sediment was associated with strong regulation of PCDD/Fs, whereas levels in bivalves did not show a decreasing trend. Octachlorinated dibenzo-<I>p</I>-dioxin (OCDD) was predominant in sediment, while tetrachlorinated dibenzofuran and OCDD were predominant in bivalves. Almost half (46%) of sediment samples exceeded the threshold effect level suggested by the US National Oceanic and Atmospheric Administration, implying ecotoxicological risks to benthic organisms. Our findings support the effectiveness of legislative action on PCDD/Fs for coastal environments of Korea.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nationwide and long-term monitoring of PCDD/Fs was conducted for coastal environment of Korea. </LI> <LI> Highest PCDD/F concentrations were found at locations close to industrial complexes and commercial harbors. </LI> <LI> A significant declining trend was observed for PCDD/Fs in coastal sediments. </LI> <LI> Approximately 46% of sediment samples exceeded the NOAA threshold guideline. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Review of Multifunctional Inverter Topologies and Control Schemes Used in Distributed Generation Systems

Ahmet Teke,Mohammad Barghi Latran 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

Recent developments in power electronics technology have spurred interest in the use of renewable energy sources as distributed generation (DG) generators. The key component in DG generators is a grid-connected inverter that serves as an effective interface between the renewable energy source and the utility grid. The multifunctional inverter (MFI) is special type of grid-connected inverter that has elicited much attention in recent years. MFIs not only generate power for DGs but also provide increased functionality through improved power quality and voltage and reactive power support; thus, the capability of the auxiliary service for the utility grid is improved. This paper presents a comprehensive review of the various MFI system configurations for single-phase (two-wire) and three-phase (three- or four-wire) systems and control strategies for the compensation of different power quality problems. The advances in practical applications and recent research on MFIs are presented through a review of nearly 200 papers.