29 research outputs found

    Spatial traffic noise pollution assessment – A case study

    Full text link
    Objectives: Spatial assessment of traffic noise pollution intensity will provide urban planners with approximate estimation of citizens exposure to impermissible sound levels. They could identify critical noise pollution areas wherein noise barriers should be embedded. The present study aims at using the Geographic Information System (GIS) to assess spatial changes in traffic noise pollution in Tehran, the capital of Iran, and the largest city in the Middle East. Material and Methods: For this purpose, while measuring equivalent sound levels at different time periods of a day and different days of a week in District 14 of Tehran, wherein there are highways and busy streets, the geographic coordination of the measurement points was recorded at the stations. The obtained results indicated that the equivalent sound level did not show a statistically significant difference between weekdays, and morning, afternoon and evening hours as well as time intervals of 10 min, 15 min and 30 min. Then, 91 stations were selected in the target area and equivalent sound level was measured for each station on 3 occasions of the morning (7:00–9:00 a.m.), afternoon (12.00–3:00 p.m.) and evening (5:00–8:00 p.m.) on Saturdays to Wednesdays. Results: As the results suggest, the maximum equivalent sound level (Leq) was reported from Basij Highway, which is a very important connecting thoroughfare in the district, and was equal to 84.2 dB(A), while the minimum equivalent sound level (Leq), measured in the Fajr Hospital, was equal to 59.9 dB(A). Conclusions: The average equivalent sound level was higher than the national standard limit at all stations. The use of sound walls in Highways Basij and Mahallati as well as widening the Streets 17th Shahrivar, Pirouzi and Khavaran, benchmarked on a map, were recommended as the most effective mitigation measures. Additionally, the research findings confirm the outstanding applicability of the Geographic Information System in handling noise pollution data towards depicting noise pollution intensity caused by traffic

    Effects of hydrophilic and lipophilic emulsifier concentrations on the characteristics of Germander essential oil nanoemulsions prepared using the nanoprecipitation technique

    Get PDF
    The Germanders (Teucrium polium L.) essential oil exhibits antioxidant and bactericidal activities against a wide range of microorganisms; however, its water insolubility, susceptibility to environmental stresses, and intense flavors limit its uses in food formulations. As a solution, in the present study, nanoemulsions of Germanders (Mentha pulegium) essential oil were prepared using a bottom-up nanoprecipitation technique. A central composite design based on the response surface methodology was implemented to investigate the effects of selected lipophilic and hydrophilic emulsifier concentrations. The proposed second-order polynomial models, with relatively high coefficients of determination, could efficiently predict alterations in response parameters due to emulsifier concentrations. The results revealed that both lipophilic and hydrophilic emulsifiers had significantly affected all characteristics of the synthesized essential oil nanoemulsions. Multi-goal optimization analysis suggested that 7.8% and 4.8% concentrations of Span 80 and Tween 80, respectively, could yield the most desirable Germanders essential oil nanoemulsions, with a mean particle size of 78.56 nm, PDI of 0.1722, DPPH radical scavenging of 83.69%, Staphylococcus aureus and Salmonella enterica growth inhibition zones of 10.5 mm and 12.7 mm, respectively. The validity of the models was confirmed by the absence of substantial variations between experimental data and modeling results. While the prepared Germander essential oil nanoemulsions demonstrated acceptable physical properties, they exhibited relatively limited chemical stability during storage at 5°C for 30 days

    Health risk assessment of heavy metal intake due to fish consumption in the Sistan region, Iran

    Get PDF
    The heavy metal (Pb, Cd, Cr, and Ni) content of a fish species consumed by the Sistan population and its associated health risk factors were investigated. The mean concentrations of Pb, Cd, and Cr were slightly higher than the standard levels. The Ni content of fish was below the maximum guideline proposed by the US Food and Drug Administration (USFDA). The average estimated weekly intake was significantly below the provisional tolerable intake based on the FAO and WHO standards for all studied metals. The target hazard quotients (THQ) of all metals were below 1, showing an absence of health hazard for the population of Sistan. The combined target hazard quotient for the considered metals was 26.94 × 10â��3. The cancer risk factor for Pb (1.57 × 10â��7) was below the acceptable lifetime carcinogenic risk (10â��5). The results of this study reveal an almost safe level of Pb, Cd, Cr, and Ni contents in the fish consumed by the Sistan population

    Onion Essential Oil-in-Water Emulsion as a Food Flavoring Agent : Effect of Environmental Stress on Physical Properties and Antibacterial Activity

    Get PDF
    Plant essential oils (EOs), which are acknowledged as generally recognized as safe (GRAS) by the Food and Drug Administration (FDA), have the potential to be used as a flavoring agent. However, there are limitations to some EOs, such as low water solubility and high volatility, which limit their application in food technology. This study was conducted to develop onion (Allium cepa) EO as a flavoring agent and determine its stability against environmental stress via an emulsification technique, with different concentrations of sodium caseinate, as a delivery system. Emulsions containing onion EO were prepared using different concentrations of sodium caseinate (3, 5, and 7% w/w) via the solvent-displacement technique. The physical properties (average droplet size, color, turbidity, and stability measurement) and antibacterial activity (agar disk diffusion method) of emulsions were then determined. Results show that emulsion with 7% (w/w) sodium caseinate was the most desirable sample in terms of physical properties and antibacterial activity. Hence, it was selected for environmental stress studies (i.e., thermal processing, freeze-thaw cycles, and ultraviolet (UV) exposure). Results revealed that all types of environmental stresses had significant (p < 0:05) effects on droplet size, color, turbidity, and stability. Generally, the environmental stresses increased the droplet size except in the freeze-thaw cycle case, while all stresses decreased the stability and lightness. All types of environmental stress treatment did not show a significant (p < 0:05) effect on antibacterial activity enhancement against Salmonella Typhimurium and Listeria monocytogenes except in the case of UV treatment against L. monocytogenes. Therefore, the present work has demonstrated the potential use of emulsion as an encapsulation and delivery system of EO flavors for food applications

    Nanoliposomes and Tocosomes as Multifunctional Nanocarriers for the Encapsulation of Nutraceutical and Dietary Molecules

    Get PDF
    Nanoscale lipid bilayers, or nanoliposomes, are generally spherical vesicles formed by the dispersion of phospholipid molecules in a water-based medium by energy input. The other nanoscale object discussed in this entry, i.e., tocosome, is a recently introduced bioactive carrier made mainly from tocopheryl phosphates. Due to their bi-compartmental structure, which consists of lipidic and aqueous compartments, these nanocarriers are capable of carrying hydrophilic and hydrophobic material separately or simultaneously. Nanoliposomes and tocosomes are able to provide protection and release of sensitive food-grade bioactive materials in a sustained manner. They are being utilized for the encapsulation of different types of bioactive materials (such as drugs, vaccines, antimicrobials, antioxidants, minerals and preservatives), for the enrichment and fortification of different food and nutraceutical formulations and manufacturing of functional products. However, a number of issues unique to the nutraceutical and food industry must first be resolved before these applications can completely become a reality. Considering the potentials and promises of these colloidal carrier systems, the present article reviews various aspects of nanoliposomes, in comparison with tocosomes, including the ingredients used in their manufacture, formation mechanisms and issues pertaining to their application in the formulation of health promoting dietary supplements and functional food products

    Antibiotic susceptibility and antimicrobial activity of lactic acid bacteria from malaysian fermented foods against biofilm-forming Escherichia coli Strains

    Get PDF
    Lactic acid bacteria (LAB) are frequently employed in the food industry as food preservatives and starter cultures due to their potentially advantageous properties. Their ability to promote numerous health benefits in fermented foods has received increased attention. However, few studies have investigated the antibacterial activity of LAB and their susceptibility to antibiotics when combating biofilm-forming Escherichia coli strains. In this study, four fermented food samples were screened for presumptive LAB cultures, including Maman pickle (M5Bi), fermented fish (PB4iii), fermented durian (T6Aiii), and fermented glutinous rice (Ta2Ai), using the API 50 CHL method. The isolates were subsequently identified as Lactobacillus plantarum, L. plantarum, Pediococcus pentosaceus, and Lactobacillus pentosus, respectively, through molecular analysis of the 16S rDNA sequencing. The isolates were then assessed for antibiotic susceptibility to amoxicillin (25 µg), chloramphenicol (30 µg), tetracycline (30 µg), and erythromycin (10 µg) using the disc diffusion method. Moreover, the antibacterial activity of LAB against eight biofilm-forming E. coli strains was evaluated using the well diffusion method. The results showed that L. plantarum from the Maman pickle sample exhibited the most significant inhibitory zone against biofilm-forming E. coli strains. Importantly, all detected LAB were resistant to the four main antibiotics tested, indicating that the safety and efficacy of probiotics must be ensured before they can be developed and commercialized

    Translators as Decision Makers: A Dialogue Protocol Study of Equivalence in Political Texts

    Get PDF
    One of the most common issues of translation as a problem-solving process is equivalence. Since equivalence as a textual relation depends on mental processes and choice of strategies, combining dialogue protocol and textual analysis, the researchers tried in the present study to identify different strategies and criteria used by undergraduate translation students to find equivalents in potentially problematic areas and, to know whether or not there is any significant relationship between those strategies and the acceptability of the equivalents. To this end, a sample of translation students at Jahrom University was asked to translate a news item in pairs. The pairs were required to report on what they were doing during the translation and record their voices. Analyzing dialogues and translation products based on Schubert (2009) the researchers found that most of the participants had resorted to internet, especially Google Translate, as an external resource. In most cases, they were also not able to provide evidence for their choices. More importantly, a significant relationship was found to be present between the choice of strategy and the acceptability of the selected equivalents. The findings of this study can provide translation scholars and teachers with valuable insights into mental processes underlying equivalence
    corecore