16 research outputs found

    An Energy Harvesting Solution for IoT Sensors Using MEMS Technology

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    The significant development of IoT sensors will play a critical role in a large number of applications. It is predicted that billions of IoT sensors will be used worldwide by 2020 [1]. Batteries are commonly utilized to power on sensors, but they are depleted and they require maintenance and replacement. Battery replacement for billions of sensors is a daunting task and battery disposal for IoT sensors can become an environmental problem. Energy harvesting from ambient sources presents a viable solution to overcome these problems. Among all energy sources, light is considered as one of the best sources due to its high energy density and availability in both indoor and outdoor environments. In order to make an energy harvesting system efficient, many methods have been proposed in the literature to extract the maximum energy while minimizing the power consumption by the energy harvesting circuitry. In this work, a boost converter circuit is designed using MEMS-based switches to reduce the leakage current and power loss caused by conventional transistor-based switches. A light energy harvesting method is also proposed utilizing available components of a typical IoT sensor. The reuse of available components in the proposed solution reduces the overall power consumption and the area overhead of the energy harvesting solution

    Optimization of Gamma-Aminobutyric Acid Production in Probiotics Extracted from Local Dairy Products in West Region of Iran using MRS broth and Whey Protein Media

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    Background and objective: Gamma-aminobutyric acid is a non-protein amino acid produced by lactic acid bacteria in fermented foods and includes unique functions in the human biological system. The aim of this study was optimization of culture media for gamma-aminobutyric acid production in probiotics extracted from local dairy products in west of Iran using two culture media of MRS broth and whey protein.Material and methods: The potential of gamma-aminobutyric acid production was assessed in Lactobacillus paracasei, Lactobacillus plantarum and Pediococos acidilactici, respectively extracted from doogh, yogurt and cheese using MRS broth and whey protein media and high performance liquid chromatography. To increase gamma-aminobutyric acid production, these media were optimized as pH (4-6), temperature (30-50°C), time (12-72 h) and glutamic acid concentration (25-250 mM).Results and conclusion: Results have shown that Lactobacillus plantarum extracted from doogh includes the highest potential of gamma-aminobutyric acid production (115.24 mg kg-1) under the following conditions of a culture temperature of 37°C, incubation time 60 h at pH 5 in MRS broth containing 50 mM of glutamic acid. After optimization of Lactobacillus plantarum media, gamma-aminobutyric acid production increased to 170.492 mg kg-1. The optimum conditions included a glutamic acid concentration of 250 mM, culture temperature at 37.27°C, pH=5.19 and an incubation time of 72 h. Based on the results, use of local isolated dairy products in west region of Iran and optimization of growth conditions increased the ability of gamma-aminobutyric acid production.Conflict of interest: The authors declare no conflict of interest

    Pregled nekih hemijskih jedinjenja i masnih kiselina u mesu gajenog šarana (cyprinus carpio) i belog amura (ctenopharyngodon idella)

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    This study was conducted to determine of some chemical compounds (proteins, lipids, moisture and ash) and fatty acids in cultured two species of common carp (Cyprinus carpio) and grass carp (Ctenopharyngodon idella). Results of this study showed that the amount of saturated fatty acids (SFA) in common carp and grass carp were 35.21 ± 2.19% and 27.18 ± 2.63%, respectively and saturated fatty acids (SFA) in common carp was higher compared to grass carp (p0.05). This study showed that PUFA was higher than SFA in Grass carp while SFA was higher than PUFA in common carp. There were significant differences in protein, lipid and moisture in two species (p0.05)

    On the relationship between vegetation cover and physiographic factors in a gallery forest in southern Urmia, NW Iran

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    This study aimed to 1) investigate the relationship between vegetation cover and physiographic factors and 2) determine the indicator species in ecological groups in a gallery forest of Darreh-Khan river in the south of Urmia, NW Iran. Minimal area method was used to determine the area of sample plots. Based on this, arboreal and herbaceous cover plots were recorded in 400 and 100 m2 plots, respectively. Using the Braun-Blanquet cover-abundance scale, arboreal and herbaceous taxa were recorded respectively in 32 and 50 sample plots centered at 0, 20, 50, 100, and 200 m along transects perpendicular to the river axis on both sides at 200 m intervals. We applied cluster and indicator species analysis in order to determine the ecological groups and indicator species. In addition, non-metric multidimensional scaling (NMS) approach was applied to analyze the relationships between vegetation and physiographic factors in the study area. Cluster analysis divided the herbaceous species into three (north-facing slope, south-facing slope, and near-river) ecological categories. The NMS analysis showed that slope and altitude are among the most influencing environmental variables on the distribution of herbaceous plants in this ecosystem. Examples of the indicator plant species in ecological group I (north-facing slope) included Astragalus persicus, Echinops bithynicus and Silene marschallii, whereas Salvia multicaulis, Onosma sericeum and Aristolochia bottae were amongst the indicator species in ecological group II (south-facing slope). Colchicum szovitsii, Galium spurium and Pimpinella anthriscoides were grouped in the third category (near-river). Moreover, woody taxa were seperated into two ecological groups: near-river (Juglans regia and Pyrus syriaca) and far-from-river (Cerasus microcarpa and Pistacia atlantica)

    Comparing the Thickness of Sternocleidomastoid Muscle in Individuals with Forward Head Posture and Normal Head Posture

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    Background and purpose: One of the most common postural disorders in today’s societies is the forward head posture (FHP) that is associated with numerous musculoskeletal complications. Considering sternocleidomastoid attachments to the neck, it seems that it would be negatively influenced by such postural deviations. The aim of this study was to compare the sternocleidomastoid muscle thickness in women with normal head posture (NHP) and FHP. Materials and methods: A case-control study was done in which 18 female students (mean age 24.5±3.3) with FHP and 18 female controls (mean age 23.4±2.5) with NHP were participated. Bilateral sternocleidomastoid muscle thickness were measured in supine position in both groups using ultrasonography. Data analysis was carried out in SPSS V.16. Results: There was no significant difference in thickness of sternocleidomastoid between individuals with FHP and NHP (P>0.05). Also, no significant difference was seen between the two groups in muscle thicknesses on either side of the neck (P> 0.05). In other words, thickness was found to be symmetric on both sides of the neck in both groups. Conclusion: According to the results, FHP did not impose any morphological changes on sternocleidomastoid muscle at the fifth cervical vertebral level. Although measurement of the thickness of this muscle in other vertebral levels is recommended for future studies

    Relationship between the Usage Count and the Number of Citations in the Journals of Library and Information Sciences: The Case of Access Type

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    Nowadays, the open access movement has become one of the most effective to make up-to-date information accessible to users. This study aimed at examining the relationship between the usage count and the number of citations of library and information sciences articles emphasizing on access type and the study used document analysis and scientometrics based on journals in the Web of Science. Open-access journals (six journals with 60 articles) and non-open access journals (ten journals with 100 articles) were selected. The www.simagojr.com site was checked to get ensured about the field of journals. The findings indicated among openaccess journals, “Information Research-An International Electronic Journal”and “Information Technology and Libraries” were the oldest and had the highest number of articles. The average number of citations was related to Transinformacao (3.3) and Journal of the Medical Library Association (112.4). The use of open access journals varied between 10.1 (Information Research) and 17.9 (Revista Espanola de Documentacion Cientifica) since 2013. Accordingly, there was no significant relationship between the usage countof the articles in open access journals and the number of citations. Among the non-open access journals, the“International Journal of Information Management” was the oldest. The average number of citations was between 120.1 for the “International Journal of Information Management” and 709.4 for”Information System Research”. The extent of using non-open access journals varied between 26.1 for “Journalofthe American Medical Informatics Association” and 181 for the “Journal of Computer -Mediated Communication”.There was significant relationship between using the articles in non-open access journals and the number of citations. The total correlation for open-access journals and non-open access journals were 0.23 and 0.40, respectively. The correlation for each journal of any access type was weak to strong

    Identification of Etiologic Agents of the Pertussis-like Syndrome in Children by Real-time PCR Method

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    The aim of this study was to recognize the identity and frequency of etiologic agents of the pertussis-like syndrome in children 6 months of age. In this study, RSV was the most frequent identified pathogen (n=20, 20%), followed by B. pertussis (n=18, 18%) and AdV (n=16, 16%). Pertussis was more frequent in spring (8%) and summer (6%). In addition, clinical symptoms of pertussis were the same as some viral pathogens, which can lead to misdiagnosis of infection. Therefore, diagnosis of pertussis should be established on the bases of both the clinical symptoms and the laboratory methods

    Biomonitoring and Subsequent Risk Assessment of Combined Exposure to Phthalates in Iranian Children and Adolescents

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    This study aimed to estimate the exposure and related health risks of phthalates, and to assess the health risks from combined exposure to three of the phthalates sharing the same mode of action (anti-androgenicity) in children. We determined the internal exposure of 56 Iranian children and adolescents aged 6 to 18 years by analyzing seven urinary metabolites of five phthalates. The estimated daily intake values derived from the biomonitoring data ranged from 0.01 µg/kg bw/day for butyl benzyl phthalate (BBP), to 17.85 µg/kg bw/day for di(2-ethylhexyl) phthalate (DEHP). The risk assessment revealed that not only the exposure to the individual phthalates, but also the combined exposure to the three anti-androgenic phthalates (DEHP, DBP, BBP) did not raise a safety concern (hazard index values averaged 0.2). The range of maximum cumulative ratio values varied from around 1 for most individuals to around 2 in some individuals, indicating that the combined exposures were dominated by one and in some cases by two of the three anti-androgenic phthalates, especially dibutyl phthalate (DBP) and/or DEHP. Based on biomonitoring data, the overall combined exposure of Iranian children to phthalates does not raise a concern, while reduction of exposure is best focused on DEHP and DBP that showed the highest hazard quotient.</p
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