729 research outputs found

    The Formation of the Intermetallic-Containing Pd2Sn Alloy: The Creation of the Isolated Adsorption Sites

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    In the current study, tin-promoted Pd / MWNTs synthesized via polyol process were developed. TEM images evidences resulted in the formation of highly-dispersed Pd-Sn nanoparticles. The formation of Pd2Sn structural phase was confirmed by XRD and TPR techniques, composed mainly of intermetallic spe-cies, supported by XPS results. In this research, we applied intermetallic-containing tin-promoted catalysts for the selective hydrogenation reaction of acetylene as the case study. The presence of a discontinuity in the Arrhenius plots could come from the kinetic factor as a result of change in acetylene coverage on Pd metallic ensembles. The intermetallic-containing assembled catalysts led to the good management of cata-lytic performance due to the creation of isolated adsorption sites on the catalyst surface, resulting in the higher ethylene selectivity. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521

    The Role of Pore Structure of SMFs-based Pd Nanocatalysts in Deactivation Behavioral Pattern Upon Acetylene Hydrogenation Reaction

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    In this research, SMFs panels were applied for further deposition of CNFs, ZnO and Al2O3 to hydro-genate selectively acetylene to ethylene. To understand the role of different structures of the examined supports, the characterization methods of SEM, ASAP, NH3-TPD and N2 adsorption-desorption isotherms were used. Following the characterization of green oil by FTIR, the presence of more unsaturated constitu-ents and then, more branched hydrocarbons formed upon the reaction over alumina-supported catalyst in comparison with the ones supported on CNFs and ZnO was confirmed, which in turn, could block the pores mouths. Besides the limited hydrogen transfer, the lowest pore diameters of Al2O3 / SMFs close to the sur-face, supported by N2 adsorption-desorption isotherms could explain the fast deactivation of this catalyst, compared to the other ones. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521

    Design and Implementation of a Compact Automated Spirulina Cultivation System for Households

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    Spirulina is considered to be the most nutritious whole food source in nature. It is promoted as a dietary supplement and an active ingredient in functional foods. Factors such as conflicts, supply chain disruptions, and economic fallout are driving food prices to unprecedented levels. Low- and middle-income populations are affected by these rising costs. The design and implementation of a compact Spirulina cultivation system to be used in the household is presented in this paper. The system contains light, temperature, pH, and turbidity sensors. All sensors are connected to microcontrollers which activate a heater, air pump, mixing pump, pool fall pump, and two LEDs according to the readings received to ensure proper and continuous growth of Spirulina. The proposed system is user-friendly, economical, and can be easily stored and operated at homes to stimulate and monitor the growth of Spirulina. The primary objective of the proposed compact cultivation system is to furnish the necessary tools for generating a nutritionally valuable food source on a smaller scale, specifically within households, at a relatively affordable cost

    Effect of Edible Coatings of Alginate and Oliveria decumbens Essential Oil on Physicochemical, Microbial and Sensory Properties of Grated Carrots During Shelf Life

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    IntroductionToday, carrots are widely used in freshly cut products, including ready to eat salads, however, its shelf life is reduced due to the damage caused on the texture of the product which accelerate the reduction of nutritional value as well as the growth of microorganisms, (Azizian et al., 2020). To increase the shelf life of freshly cut products, it is recommended to use coatings on the surface of these products. Alginate is a hydrophilic biopolymer and having unique colloidal characteristics, it demonstrates a suitable coating function. Olivas et al. (2008) showed that by coating fresh apple slices with alginate and antimicrobial agents increased the shelf life of apple and decreased weight loss. Among the native plants of Iran, we can mention the Oliveria plant, which belongs to the Amblifra family. The aerial parts of this plant have a significant amount of essential oils (EOs). Researches by Amin et al. (2005) on the antimicrobial properties of Oliveria essential oils have shown a broad-spectrum antimicrobial activity against all studied organisms, and this effect is comparable to that of commercial antibiotics. Packaging with modified atmosphere is one of the best ways to increase the shelf life of fruits and vegetables. The purpose of this study was to investigate the effect of alginate and Oliveria essential oils on the physicochemical and microbial characteristics of grated carrots in polypropylene packages with modified atmosphere during storage. MethodsEssential oil of Oliveria plant was extracted, dehydrated by sodium sulfate and placed in sealed glass container and stored at 4˚C until using. Carrots prepared from Wilmoren cultivar. An industrial crusher crushed the carrots, and samples were coated by treatment solutions. Two treatments of coating were prepared, one as control with 0% and the other one with 1.5% alginate with stirring and moderate heat (50-60°C) (Lu et al., 2009). Then the Oliveria EO was added to the alginate solution at the specified concentration. The resulting solution was deaerated at 25˚C.T1: control sample (without coating)T2: 1.5% alginateT3: 150 ppm Olivieria EOT4: 250 ppm Olivieria EOT5: 1.5% alginate and 150 ppm of Olivieria EOT6: 1.5% alginate and 250 ppm of Olivieria EOAfter weighing (250 g), the grated carrots (control and coated) were placed in 10 g polypropylene packages of suitable food grade in dimensions of 50 × 190 × 144 cm and the package was injected with 5% O2, 5% CO2 and 90% N2. The packages were then stored in the refrigerator for 12 days at 4±1˚C. All experiments were performed on days 1, 3, 6, 9, and 12. Evaluation of Chemical, Microbial and Sensory CharacteristicsA pH meter used for pH determination (Rad et al., 2020). The acidity measured based on Rocha et al. (2007) method.The weight was reported using pre and post-storage weight. The carotenoid concentration calculated by Rocha et al. (2007) method. Total soluble solids determined by refractometer (Rad et al., 2020). Ascorbic acid content measured by Falahi et al. (2013) method. The L*, a*, b* and WI (white index) indicators of grated carrots evaluated by Hunter lab system. A 5-point hedonic test was used to assess sensory attributes(Ajnevardi et al., 2002). The internal gas concentration evaluated by Ullsten & Hedenqvist (2003) method. Total count microorganisms, mold, and yeast were counted according to the method of Azizian et al. (2020). Data AnalysisThis study was conducted in a completely randomized design with factorial form to investigate the effect of independent variables of type of alginate coating (2 levels), essential oil (3 levels) and time (5 levels) on the physicochemical properties of grated carrots (3 replications) and total counting, mold and yeast (2 replications). Mean comparison was performed using LSD test at 5% probability level and SPSS software was used to statistically analyze data. ResultThe results showed that the level of acidity, carotenoid and acid ascorbic, the amount of L* and sensory (color, quality, flavor, odor) scores reduced during time. By contrast the level of pH, weight loss, the amount of a*, b*, CO2, TSS and total counts increased (P<0.05). Also, with increasing the concentration of essential oils and alginates, the amount of acidity, carotenoids, ascorbic acid, L* increased and pH, weight loss, TSS, a*, b*, CO2 and total count decreased (P<0.05). Escherichia coli, mold and yeast count of the samples did not show any growth from the mentioned treatments until the 12th day. Overall, the Oliveria essential oil and alginate were effective in improving the properties of grated carrots under the modified atmosphere during storage. ConclusionThe study showed that Oliveria EO and alginate added to grated carrots in modified atmosphere packaging during storage was effective in reducing respiration, water loss, microbial load and increased the shelf life. Treatment containing 1.5% alginate and 250 ppm Oliveria EO showed the best chemical, microbial and sensory characteristics. The results indicated that by packing under modified atmosphere and coating by alginate and Oliveria EO, a new carrot product provided to the market with maintaining durability and quality characteristics during storage

    Study of plasmid profile and alkane hydroxylase genes in crude-oil degrading bacteria isolated from the Persian Gulf

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    610-615Bioremediation, using microorganisms, especially hydrocarbon-degrading bacteria are inexpensive and eco-friendly methods to reduce oil pollutions. Plasmids containing hydrocarbon-degrading genes encode the enzymes necessary for the derivative pathways are important for bioremediation. The aim of the present work was to study the plasmid profile of bacterial strains isolated from crude-oil contaminated sites in the Persian Gulf in previous researches. In this study, plasmids were extracted from 21 strains using alkaline lysis method. Then, alkane hydroxylase gene groups (I, II, III) were detected in extracted plasmids using specific primers by PCR. The results of this study indicated that eight crude oil degrading strains out of 21 had plasmid. The results of PCR amplification confirmed that 50 % of plasmid containing strains had alkane hydroxylase gene group (I), 75 percent of them had alkane hydroxylase gene group (III) and none of them had alkane hydroxylase gene group (II)

    Prevalence of legionella species in water resources of Iran: A systematic review and meta-analysis

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    Background: Legionella species are ubiquitous and naturally found in lakes, rivers, streams and hot springs, and other water resources. The present study aimed to investigate the prevalence of Legionella species in water resources of Iran by a systematic review and meta-analysis. Methods: In search of papers relevant to the prevalence of Legionella in water resources of Iran, the scientific information database in both English and Persian languages was used. The search was limited to studies between the year 2000 and end of July 2016. Each cohort and cross-sectional study that reported the contamination of water with Legionella was included in the present study. For data analysis, comprehensive meta-analysis software with Cochran�s Q and I2 tests were used. P values less than 0.05 were considered statistically significant. Results: The prevalence of Legionella species in water resources of Iran was 27.3 (95 CI: 25.3-29.3). The prevalence of Legionella spp. in hospital water, dental settings water, and other water resources were 28.8 (95 CI: 26.4-31.2), 23.6 (95 CI: 16.1-33.2), and 29.6 (95 CI: 25.6-33.8), respectively. The most common Legionella species was L. pneumophila with a prevalence of 60.5 (95 CI: 53.3-67.2) and the prevalence of all other species was 52.5 (95 CI: 44.7-60.2). The highest prevalence was reported in Isfahan with 55.7 (95 CI: 48.0-63.0). Conclusion: Based on the results, the prevalence rate of Legionella species in water resources of Iran was high and the most common Legionella species was L. pneumophila. © 2018, Shiraz University of Medical Sciences. All rights reserved

    Design and Implementation of a Compact Automated Spirulina Cultivation System for Households

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    Spirulina is considered to be the most nutritious whole food source in nature. It is promoted as a dietary supplement and an active ingredient in functional foods. Factors such as conflicts, supply chain disruptions, and economic fallout are driving food prices to unprecedented levels. Low- and middle-income populations are affected by these rising costs. The design and implementation of a compact Spirulina cultivation system to be used in the household is presented in this paper. The system contains light, temperature, pH, and turbidity sensors. All sensors are connected to microcontrollers which activate a heater, air pump, mixing pump, pool fall pump, and two LEDs according to the readings received to ensure proper and continuous growth of Spirulina. The proposed system is user-friendly, economical, and can be easily stored and operated at homes to stimulate and monitor the growth of Spirulina. The primary objective of the proposed compact cultivation system is to furnish the necessary tools for generating a nutritionally valuable food source on a smaller scale, specifically within households, at a relatively affordable cost

    Uses of carotenoid-rich ingredients to design functional foods: a review

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    This is the final version. Available from the International Society for Nutraceuticals & Functional Foods (ISNFF) via the DOI in this recordCarotenoids are isoprenoids that are extensively dispersed in foods that have always been part of the human diet. Certain carotenoids can be transformed into retinoids with vitamin A activity, which is needed for humans. Additionally, they are far more flexible, since they may be found in foods not just as sources of vitamin A, and also as natural colors, antioxidants, and health-promoting substances. Functional foods provide health advantages in addition to basic nourishment. They can be found in a variety of forms, including whole, fortified, enriched, or enhanced meals. A flood of information about the health advantages of functional foods has been supplied by several epidemiological research. This review discusses the factor for healthy and sustainable usage of carotenoidrich ingredients for the design of functional food products primarily intended for health promotion. Furthermore, data on sources, intakes, and variables influencing bioavailability are summarized

    Comparative study of goldfish growth and survival rate feeding by fairy shrimp (Phallocryptus spinosa), Artemia and concentrate diet

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    The diet quality and type has a great role in aquatic animals and leads to increase of resistance against diseases and good growth. Cultured andornamental fish do not access to live and selected food due to captivity condition. Threfore, they should be provided with complete diet similar to natural food in captive condition. Carotenoid pigments are responsible of flesh pigmentation of edible fish and skin color of ornamental fish. The accumulation of this pigments in fish tissue has a greate importance in marketing and hence due to lack of its synthesis, carotenoids shoud be added to diet of cultured fish. As the synthetic carotenoids are harmful to the environment , there is a greate interest to use natural carotenoids in ornamental fish diets to obtain bright color. This study was carried out to compare the effects of diets containing Artemia urmiana and Phallocryptus spinosa supplements and commercial feed on growth and survival of goldfish fingerlings, quality of skin color, amounts of total carotenoids, Astaxantin, Canthaxantin and beta-carotene inCultured Carassius auratus during 90 days. The culture medium were contained glass aquaria in controlled condition and suitable for goldfish growth with 12 L: 12 D photoperiod and water temperature of 28±1 oC 3 test groups were included: treatment 1 fed with concentrate diet , treatment 2 fed with concentrate and frizzed Phallocryptus spinosa with tha same concentrations and treatment 3 fed with concentrate and frizzed Artemia urmiana with the same concentrations . Each treatment contains 2 replications and each replication consisted of 30 goldfish. In this study, The amounts of total carotenoids using spectrophotometer modelWPA, astaxantin, canthaxantin and beta-carotene using HPLC model Younglin, UK, were determined in the skin of Carassius auratus at the end of the exprement period. The results revealed that the most growth rate (GR), specific growth rate and condition factor (CF) were 0.11 ±0.006, 0.34 ± 0.015 and 3.96 ± 0.10, respectively which due to treatment 3 and the most weight gain and length gain including 8.57± 1.18g and 31.54± 3.33 mm, respectively due to treatment 2 .During rearing period, there was not any significant difference among treatments (p>0.05). The analysis of obtained data showed that there was a significant difference between diets containing live food and concentrate diet (p<0.05). The results revealed that live food enhanced skin color of Carassius auratus compared to concentrate diet. Also, the most pigmentation obtained from the diet contained fairy shrimp. As, in concentrate, concentrate and fairy shrimps, concentrate and Artemia diets amounts of total carotenoids at 450 nm wave length were 1.09, 3.90 and 2.07 mg/100, asthaxantin were 84.57, 205.82 and 102.24 ng/g and canthaxanthin were 0.24, 35.79 and 30.64 ng/g and carotenoid were 34.73, 138.78 and 69.77 ng/g, respectively. The use of fairy shrimp compared to Artemia in the diet can be significantly increased the amounts of carotenoids especially asthaxanthin in the skin of goldfish (p<0.05). Therefore fairy shrimps can be used as a suitable for artemia and high cost synthetic pigments to enhance color of ornamental fish

    Native drivers of fish life history traits are lost during the invasion process

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    © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Rapid adaptation to global change can counter vulnerability of species to population declines and extinction. Theoretically, under such circumstances both genetic variation and phenotypic plasticity can maintain population fitness, but empirical support for this is currently limited. Here, we aim to characterize the role of environmental and genetic diversity, and their prior evolutionary history (via haplogroup profiles) in shaping patterns of life history traits during biological invasion. Data were derived from both genetic and life history traits including a morphological analysis of 29 native and invasive populations of topmouth gudgeon Pseudorasbora parva coupled with climatic variables from each location. General additive models were constructed to explain distribution of somatic growth rate (SGR) data across native and invasive ranges, with model selection performed using Akaike's information criteria. Genetic and environmental drivers that structured the life history of populations in their native range were less influential in their invasive populations. For some vertebrates at least, fitness-related trait shifts do not seem to be dependent on the level of genetic diversity or haplogroup makeup of the initial introduced propagule, nor of the availability of local environmental conditions being similar to those experienced in their native range. As long as local conditions are not beyond the species physiological threshold, its local establishment and invasive potential are likely to be determined by local drivers, such as density-dependent effects linked to resource availability or to local biotic resistance
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