NITRITE REMOVAL FROM AQUEOUS SOLUTION USING SURFACE MODIFIED MAGHEMITE NANOPARTICLES

BEHRUZ MIRZAYI,ALI NEMATOLLAHZADEH,FOROUGH FIROUZNIA,SIMA HEYDARI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.2

In the present work, maghemite nanoparticles (MNP) was synthesized by a simpli¯ed methodand then modi¯ed by sodium dodecyl benzene sulfonate (NaDBS) for the removal of nitrite fromaqueous solution. The prepared nanoparticles were characterized by Scanning electron mi-croscopy (SEM), X-ray di®raction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The SEM image and XRD analysis showed that the average particle size and crystallite of themaghemite nanopaticles are ca. 32.7 nm and 33.5 nm, respectively. Di®erent parameters namely,pH of the adsorption solution, adsorbent dosage and spectrophotometric reagents were opti-mized. Spectrophotometric determination of nitrite in an optimized condition showed that theMNP is able to deplete over 88% of nitrite from the initial solution. Moreover, dynamicadsorption study per se con¯rmed the shortest necessary contact time (ca. 6 min) in theadsorption process of nitrite which is quite encouraging from a practical and industrial point ofview. The kinematic study revealed that the nitrite adsorption is a pseudo-¯rst-order process. In addition, two di®erent models (Freundlich- and kinetic-type model) were developed for theadsorbent dosage e®ect on nitrite adsorption. A Freundlich-type model manifested high coe±-cients of regression, indicating its robustness.

Amino Acids and Protein Digestibility and Metabolizable Energy Availability of Barley Ration in Response to Grind^® Enzyme in Broiler Chickens

Saki, Ali Asghar,Mirzayi, S.,Ghazi, Sh.,Moini, M.M.,Naseri Harsini, R. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.5

Increasing accuracy of broiler diet formulation based on amino acid digestibility in comparison to application of total amino acids could lead to more feed efficiency and productivity. This experiment was conducted for determination of sampling site (excreta and ileum) and recognition of the effects of a commercial enzyme ($Grind^{(R)}$ Danisco, Finland) on metabolizable energy, protein and amino acid digestibility of barley. This study was modulated by a marker in 21-day old Arbor Acres chickens. Corn-soybean meal was used as a control diet and, in the other two treatments, barley (at a level of 40%) with and without enzyme as the test ingredient were supplemented to the basal diet. Chromic oxide was included in all diets (0.5%) as an indigestible marker. Apparent metabolizable energy (AME), corrected by nitrogen (AMEn) and apparent digestibility of aspartic acid, glutamic acid, serine, glycine, alanine, tyrosine, valine and methionine were significantly (p<0.05) higher in feces than ileum. Protein digestibility of diet and barley was significantly (p<0.05) higher in the ileum than in feces. Apparent digestibility of tryptophan, proline, methionine, phenylalanine and lysine was increased significantly (p<0.05) by enzyme supplementation. In contrast, no response was observed in AME, AMEn, and protein digestibility of the diet and barley by enzyme supplementation. The results of this study have shown that AME and amino acid digestibility were increased in feces, in contrast an adverse effect was observed for protein digestibility of the diet and barley.

The Impact of Redundancy and Teamwork on Resilience Engineering Factors by Fuzzy Mathematical Programming and Analysis of Variance in a Large Petrochemical Plant

Azadeh, Ali,Salehi, Vahid,Mirzayi, Mahsa Occupational Safety and Health Research Institute 2016 Safety and health at work Vol.7 No.4

Background: Resilience engineering (RE) is a new paradigm that can control incidents and reduce their consequences. Integrated RE includes four new factors-self-organization, teamwork, redundancy, and fault-tolerance-in addition to conventional RE factors. This study aimed to evaluate the impacts of these four factors on RE and determine the most efficient factor in an uncertain environment. Methods: The required data were collected through a questionnaire in a petrochemical plant in June 2013. The questionnaire was completed by 115 respondents including 37 managers and 78 operators. Fuzzy data envelopment analysis was used in different ${\alpha}$-cuts in order to calculate the impact of each factor. Analysis of variance was employed to compare the efficiency score means of the four abovementioned factors. Results: The results showed that as ${\alpha}$ approached 0 and the system became fuzzier (${\alpha}=0.3$ and ${\alpha}=0.1$), teamwork played a significant role and had the highest impact on the resilient system. In contrast, as ${\alpha}$ approached 1 and the fuzzy system went toward a certain mode (${\alpha}=0.9$ and ${\alpha}=1$), redundancy had a vital role in the selected resilient system. Therefore, redundancy and teamwork were the most efficient factors. Conclusion: The approach developed in this study could be used for identifying the most important factors in such environments. The results of this study may help managers to have better understanding of weak and strong points in such industries.

The Impact of Redundancy and Teamwork on Resilience Engineering Factors by Fuzzy Mathematical Programming and Analysis of Variance in a Large Petrochemical Plant

Ali Azadeh,Vahid Salehi,Mahsa Mirzayi 한국산업안전보건공단 산업안전보건연구원 2016 Safety and health at work Vol.7 No.4

Background: Resilience engineering (RE) is a new paradigm that can control incidents and reduce their consequences. Integrated RE includes four new factorsdself-organization, teamwork, redundancy, and fault-tolerancedin addition to conventional RE factors. This study aimed to evaluate the impacts of these four factors on RE and determine the most efficient factor in an uncertain environment. Methods: The required data were collected through a questionnaire in a petrochemical plant in June 2013. The questionnaire was completed by 115 respondents including 37 managers and 78 operators. Fuzzy data envelopment analysis was used in different a-cuts in order to calculate the impact of each factor. Analysis of variance was employed to compare the efficiency score means of the four abovementioned factors. Results: The results showed that as a approached 0 and the system became fuzzier (a = 0.3 and a = 0.1), teamwork played a significant role and had the highest impact on the resilient system. In contrast, as a approached 1 and the fuzzy system went toward a certain mode (a = 0.9 and a = 1), redundancy had a vital role in the selected resilient system. Therefore, redundancy and teamwork were the most efficient factors. Conclusion: The approach developed in this study could be used for identifying the most important factors in such environments. The results of this study may help managers to have better understanding of weak and strong points in such industries.

Dietary Phytochemical Index and the Risk of Breast Cancer: A Case Control Study in a Population of Iranian Women

Bahadoran, Zahra,Karimi, Zeinab,Houshiar-Rad, Anahita,Mirzayi, Hamid-Reza,Rashidkhani, Bahram Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

In this study we assessed the dietary phytochemical index in relation to the risk of breast cancer in women. This case-control study was conducted on 100 incident breast cancer cases and 175 healthy controls. Data regarding socio-demographic factors, medical history, medications, and anthropometric measurements were collected. Dietary data were obtained using a validated food frequency questionnaire and a energy-adjusted dietary phytochemical index (PI) was calculated. The odds ratios of breast cancer were assessed across energyadjusted PI quartile categories. The mean age of participants was $46.2{\pm}8.9$ and $45.9{\pm}9.4$ years in cases and controls, respectively. The mean PI across quartile categories was $13.9{\pm}2.6$, $21.1{\pm}1.8$, $26.7{\pm}2.1$, $41.6{\pm}10.2$ in the first, second, third and fourth quartiles, respectively. After adjustment for all potential confounders, the risk of breast cancer in the forth quartile of dietary PI was significantly decreased (OR=0.08, 95%CI=0.01-0.84). Higher intake of phytochemical-rich foods is associated with lower risk of breast cancer.