115 research outputs found
Separation and Preconcentration of Trace Amounts of Manganese and Nickel from Natural Water Samples by a Diimine Derivative Schiff Base-Coated Silica-Gel Minicolumn
An efficient method for preconcentration of trace amounts of Mn (II) and Ni (II) ions by using a minicolumn (10 mm × 30 mm i.d.) filled with a diimine derivative Schiff base on silica-gel has been reported. The retained analytes on the column were recovered with 5 mL of mixture of nitric acid 5 mol L−1 and methanol (1 : 1) and were determined by a flame atomic absorption spectrometer. Different factors including pH of sample solution, sample volume, amount of sorbent, eluent volume, and interference of other ions have been studied and the optimized conditions developed were utilized for the trace determination of Mn (II) and Ni (II) in natural water samples. The recoveries for the analytes under the optimum working conditions were higher than 98%. The relative standard deviations of the determinations (10 replicate analyses) at 25 μg L−1 of Mn (II) and Ni (II) were 2.5% and 2.3%, respectively. The limit of the detection (3s, n=10) for analytes were found to be 0.20 μg L−1 for Mn (II) and 0.15 μg L−1 for Ni (II). The proposed method was applied to the analysis of natural water samples with satisfactory results
Medicinal plants and phytotherapy in Iran: Glorious history, current status and future prospects
This study is an endeavour to analyse the status of medicinal plants research in Iran. Because of its exceptional phytogeography, Iran has a unique and diverse flora. It is estimated that, 8167 species of vascular plants are present in Iran of which about 2075 have medicinal importance. Situated at the heart of the Silk Road, Iran enjoys a mix of cultures providing a rich backbone for the development of traditional herbal medicine practices. Notwithstanding the brilliant history in traditional medicine and success of investigation to produce herbal medicines, attempts in recent decades, face many challenges. Many text and paper about these concerns were never translated in English. Strong need was felt to record such data of medicinal plants of Iran, their conservation status and related information. The scattered literature over medicinal plants of Iran were collected, analysed and presented in this review, highlighting not only their therapeutic potential but also concerns about product authenticity, quality, safety and efficacy. This will provide ways for future scientific research in this area. Awareness of critical issues in traditional medicinal herbs can play a pivotal role in the discovery and development of plant based drugs and to sustain consumer confidence
Analysis of Urban Environment Sustainability in Kurdish Cities of Iran Using the Future Study Approach (Case Study: Saqqez City)
The present study attempts to analysis the spatial transformations in the urban environment scale by utilizing the natural step foresight approach in the context of urban environment indicators. To obtain this goal, the methods applied herein included descriptive-analytical studies, document and questionnaire in the frame of Delphi model and software analyzes. Initial discussions were held with 50 academic elites and executives in Saqqez city as the statistical population, followed by the identification of 78 variables in the frame of 16 general classifications. The results showed that the obtained fill rate was equal to 95.79% with two data iterations, which represented the highest level of variables influencing each other. According to the findings, the integrated urban environmental management index (ME4) with 188 scores had uppermost direct impact on other variables. Moreover, the index of development and promotion of urban recycling regulations with 5,585,944 calculated raw values presented the most indirect impact on other variables. Finally, the use of SMIC resulted in favorable, intermediate and catastrophic scenarios by considering the identified key driving forces
Using Multi-Objective Land Allocation Model to Simulate Urban Growth: The Case of Sarakhs Border City in Iran
This chapter’s purpose is to simulate urban growth of Sarakhs, using a Multi-Objective Land Allocation (MOLA) model. To achieve this goal, Landsat 7 and 8 and Sentinel 2A satellite images from 2003 to 2020, and 13 variables affecting the location of land uses with spatial decision model (SDM), multi-criteria evaluation (MCE), and MOLA model were used. Considering the increase in the city’s population from 2020 to 2030 and the possibility of turning the city into a Free Economic Industrial Zone (FEIZ), about 322 hectares of land for residential use and 500 hectares for industrial use were estimated until 2030. By using MOLA model, the location of residential and industrial land use with a distance from agricultural lands was simulated in the west of the city. The result of the residential land use simulation is in line with the projected development direction of the City Master Plan to a large extent. But industrial land use is predicted in the vicinity of the Special Economic Zone (SEZ) in the west of the city. Therefore, the research results can be used in simulating of urban growth due to high speed, accuracy, and low-cost compared to traditional methods of preparing Master Plans in the Third World cities
Practical View-Change-Less Protocol through Rapid View Synchronization
The emergence of blockchain technology has renewed the interest in
consensus-based data management systems that are resilient to failures. To
maximize throughput of these systems, we have recently seen several prototype
consensus solutions that optimize for throughput at the expense of overall
implementation complexity, high costs, and reliability. Due to this, it remains
unclear how these prototypes will perform in real-world environments. In this
paper, we present the Practical View-Change-Less Protocol PVP, a
high-throughput, simple, and reliable consensus protocol. Central to PVP is the
combination of (1) a chained consensus design for replicating requests with a
reduced message cost; (2) the novel Rapid View Synchronization protocol that
enables robust and low-cost failure recovery; and (3) a high-performance
concurrent consensus architecture in which independent instances of the chained
consensus operate concurrently to process requests with high throughput and
without single-replica bottlenecks. Due to the concurrent consensus
architecture, PVP greatly outperforms traditional primary-backup consensus
protocols such as PBFT (by up to 430%), Narwhal (by up to 296%), and HotStuff
(by up to 3803%). Due to its reduced message cost, PVP is even able to
outperform RCC, a state-of-the-art high-throughput concurrent consensus
protocol, by up to 23%. Furthermore, PVP is able to maintain a stable and low
latency and consistently high throughput even during failures.Comment: 16 pages, 14 figure
Determination of aflatoxin M1 levels in Iranian white and cream cheese
A screening survey on the occurrence of aflatoxin M1 (AFM1) was accomplished on 210 cheese samples
composed of white cheese (116 samples) and cream cheese (94 samples) purchased from popular markets
in central part of Iran (Esfahan and Yazd provinces). The quantitative analysis of AFM1 levels in the
samples was performed by using the competitive enzyme-linked immunosorbent assay (ELISA) technique.
Aflatoxin M1 at measurable level (50 ng/kg) was detected in 161 (76.6%) samples, consisting of
93 (80.1%) white and 68 (72.3%) cream cheese samples. The concentration of AFM1 in the samples ranged
from 52.1 to 785.4 ng/kg. Comparing to legal regulation (250 ng/kg) accepted by some of the countries,
24.2% of the samples exceeded the accepted limit. Among these, the AFM1 levels in 28.4% of white and
19.1% of cream cheese samples were not in accordance with the safety limit. The results indicated that
contamination of the samples with AFM1 in such a level appear to be a potential hazard for public health.
This paper represents the data of the first survey on the occurrence of AFM1 in cheeses consumed in central
part of Ira
A novel separation/preconcentration procedure using in situ sorbent formation microextraction for the determination of cobalt (II) in water and food samples by flame atomic absorption spectrometry
AbstractA new, simple, low cost, and rapid solid phase extraction method, that was named in situ sorbent formation microextraction (ISSFME), was developed for the selective separation and determination of cobalt (II) in various water and food samples. In the present work, cetyltrimethylammonium bromide was used as a cationic surfactant, perchlorate ion as an ion-pairing agent, and 2-nitroso-1-naphthol as a complexing agent. After extraction, the concentration of cobalt was determined by flame atomic absorption spectrometer. Several variables that affect the extraction efficiencies were investigated and optimized. Under the optimized conditions, the limit of detection was 0.8μgL−1 with a preconcentration factor of 50. The RSD for 10 replicate measurements of 50μgL−1 of cobalt was 2.3%. The accuracy and applicability of the method were tested by evaluating the amount of cobalt in water certified reference materials and various water and food samples
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