86 research outputs found
Monitoring of Cochlodinium polykrikoides blooms as a harmful phenomenon in the Persian Gulf (2010-2011)
The monitoring of the harmful bloom of Cochlodinium polykrikoides in the northern Persian Gulf was studied during 2010 to 2011. The results revealed that in the waters of Hormozgan Province, the Diatoms and Dinoflgellates had the highest frequency. No significant difference was found for amount of nutrients in three sub- regions. The bloom of C. polykrikoides was higher in central sub-region in spring and was occurred in the eastern sub-region in summer, but no mortality of fishes was recorded. In Bushehr Province, four classes of Bacillaryophyceae, Cyanophyceae, Dynophyceae and Prymnesiophyceae were determined. Furthermore significant different values of nutrients were recorded. In waters of Khuzestan Province, different values of NH4 were measured for different months. In total, the measured ratio of N: P in all months was lower than Redfield Ratio (16:1) in which subsequently the environmental condition was not suitable for bloom of C. polykrikoides
Isolation and identification of histamine-forming bacteria in frozen skipjack tuna (Katsuwonus pelamis)
In this study a series of experiments were carried out to detect and identify histamine-forming bacteria and analyze histamine content for evaluation of current harvesting and post harvesting procedures. The target fish was skipjack (Katsuwonus pelamis) in which the samples were collected from Oman Sea waters harvested by gillnet or purse seine methods. Bacteriological isolates and the amount of histamine were obtained from the muscle around the gills. The obtained results indicated that the average of total and psychrophilic counts were 7.2×10⁶ and 2.9×10⁶ CFU/g, respectively. Histamine-forming bacteria occurred on a low scale of total bacterial load with the mean of 2.8 ×10² CFU/g. Diverse bacterial isolates were identified as histamine-forming bacteria. Amongst them, Proteus spp. with the highest abundance in samples contributed 24.5% followed by Clostridium perfringens (22.5%), Klebsiella spp. (15.0%), Enterobacter spp. (11.5%) and the other isolates (26.5%). In comparison with USFDA standard, the amount of histamine in 22.2 and 42.2% of the examined samples were 20-50ppm, and >50ppm, respectively. Therefore, there are seafood safety risks in the current harvesting and post harvesting methods used in skipjack industry and proper preventional methods for histamine formation are recommended
Intelligent monitoring interfaces for coal fired power plant boiler trips: A review
A major source of contemporary power is a Coal-fired Power Plant. These power plants have the capacity to continuously supply electricity to almost 500,000 residential and business units. An essential component of a Coal-fired Power plant is automation. A feature of this automation is an Intelligent System developed for the Power Plant. These Intelligent Systems have different configurations and design. This research studies the various Intelligent Monitoring Interfaces developed for Coal-fired Power Plant Trips, their advantages, disadvantages and proposes a new Intelligent Monitoring Interface that would alleviate the disadvantages of the existing systems. Current systems that use Neural Network models are investigated. The improved Intelligent Monitoring Interface as proposed in this paper is a modification of the existing monitoring system for the Coal-fired Power Plant Boiler Trips. It is expected to improve the overall system by implementing remote accessibility and interactability between the plant operator and the control system interface. The interface will also assist the operator by providing guidelines to troubleshoot the identified trips and the remote server application will allow data collected to be viewed anytime, anywhere
The effective factors on place attachment in residential environments
ABSTRACTBACKGROUND AND OBJECTIVES: Place attachment is among the most important aspects of the interaction between people and their places, to keep residential environments safe, sustained, and resilient. This study aims to identify the factors that influence the creation and enhancement of place attachment in residential settings, with a focus on physical elements. Given the significance of these factors in architecture and facility programming, the study aims to provide architects and designers with effective strategies for designing and redesigning residential environments. The results of this study on place attachment can be utilized in the architectural facility programming process and design decision-making. METHODS: This study proposed a theoretical framework in which the relationship between subjective and objective physical and individual characteristics and time were the main components of making sense of place attachment. Using a survey method, the study investigated the significance of place attachment among residents of the 600-unit residential complex in Mashhad, Iran, through a questionnaire divided into three sections. The first section focused on individual characteristics and time spent in the complex, while the second and third sections measured the objective and subjective physical characteristics and the extent of people's attachment to the complex, respectively. The data from 158 participants were analyzed using SPSS and SmartPLS software.FINDINGS: Results of SPSS analysis showed objective physical characteristics (p<.01, r=.241), as well as the subjective physical characteristics (p<.01, r=.223) and time (p<.01, r=.237), were the most important components affecting place attachment, highlighting the role of physical strategies used in the residential complex for creating and developing this feeling. Considering these physical factors affecting the establishment and enhancement of place attachment emphasizes the role of architects and planners in satisfying this crucial human need which directly affects people's personal and social health.CONCLUSION: The results revealed time, subjective, and objective physical characteristics are three factors that have a direct impact on place attachment. Objective physical characteristics have a direct impact on place attachment and also indirectly impact it through their effect on subjective physical characteristics. On the other hand, the relationship between individual characteristics and place attachment is indirect, as individual characteristics affect the time spent in a place, and an increase in time spent leads to a stronger place attachment. The findings can be employed extensively in architectural programming in residential environments to improve the quality of life
Deriving High-Precision Radial Velocities
This chapter describes briefly the key aspects behind the derivation of
precise radial velocities. I start by defining radial velocity precision in the
context of astrophysics in general and exoplanet searches in particular. Next I
discuss the different basic elements that constitute a spectrograph, and how
these elements and overall technical choices impact on the derived radial
velocity precision. Then I go on to discuss the different wavelength
calibration and radial velocity calculation techniques, and how these are
intimately related to the spectrograph's properties. I conclude by presenting
some interesting examples of planets detected through radial velocity, and some
of the new-generation instruments that will push the precision limit further.Comment: Lecture presented at the IVth Azores International Advanced School in
Space Sciences on "Asteroseismology and Exoplanets: Listening to the Stars
and Searching for New Worlds" (arXiv:1709.00645), which took place in Horta,
Azores Islands, Portugal in July 201
The RoPES project with HARPS and HARPS-N. I. A system of super-Earths orbiting the moderately active K-dwarf HD 176986
We report the discovery of a system of two super-Earths orbiting the
moderately active K-dwarf HD 176986. This work is part of the RoPES RV program
of G- and K-type stars, which combines radial velocities (RVs) from the HARPS
and HARPS-N spectrographs to search for short-period terrestrial planets. HD
176986 b and c are super-Earth planets with masses of 5.74 and 9.18
M, orbital periods of 6.49 and 16.82 days, and distances of 0.063
and 0.119 AU in orbits that are consistent with circular. The host star is a
K2.5 dwarf, and despite its modest level of chromospheric activity (log(R'hk) =
- 4.90 +- 0.04), it shows a complex activity pattern. Along with the discovery
of the planets, we study the magnetic cycle and rotation of the star. HD 176986
proves to be suitable for testing the available RV analysis technique and
further our understanding of stellar activity.Comment: 21 pages, 24 figures, 7 table
Study of measuring Tilapia (Oreochromis niloticus) freshness using quality index method (QIM)
Fish freshness by using QIM and according to scoring to all of parts variable (positive and negative) was by sensory method and finally become the parameters of quantitative and qualitative with statistical analysis is based, tables used in volatility score of 0 to 23, with a score of 0 to 3 respectively, for their excellent quality, 3 to 7good, from 7 to 10 and from 10 to above average evaluation is unacceptable. In this study to measure the freshness of fish species Nile Tilapia (Oreochromis niloticus), black and red in 4 treatments, whole fish and empty stomach is considered and the objective of this study was to calculate the survival rate of fish in ice cover practically immediately after harvest to measure qualitative factors (sensory evaluation, chemical and microbiological).For this study 50 pieces of red and 50 pieces black Tilapia after weighed, washed and then selection 25 pieces for each treatment in unlit, ratio of 3 to 1 (ice - fish) was covered .The mean (± SD) change in temperature the fish flesh during study were between 0.2 ±0.07 a to 0.3 ±0.1a degrees Celsius, that need to raise the quality temperature is maintained at 0 degrees Celsius in unlit center. Fish covered with ice keep at ambient temperature, and after measuring the change free nitrogen, pH and microbial tests, the results showed maximum shelf life of whole fish in ice cover 9 and for empty stomach fish was7 days .And also statistical analysis (Duncan test) of data between treatments (Whole and empty fish covered in ice ) was significant (P<0.05)
Study on the possibility of producing low-fat spread using gelatin extracted from cultured carp wastes
By-products consist of more than half of the total weight of fish. Most part of these wastes made from connective tissue proteins that provide good potential to produce gelatin. Nowadays, consumers are more health conscious and have responded to the call for a diet that contains low calorie and low fat. This work involved the characterization of a low-fat spread made of fish gelatin as gelling agent, emulsifier and fat replacer. Six treatments with Fish gelatin (FG) to pectin ratio 1:1 and 2:1, with pectin concentration of 1, 2 and 3%, were produced and evaluated for quality changes and storage-life at refrigerated storage. The results showed that prepared emulsions were physically stable and no phase separation observed during 8 wks. The pH of treatments was 4.5 to 4.9. The moisture content of treatments varied from 68.9% for T1 (FG/pectin ratio 1:1) to 65.4% for T6 (FG/pectin ratio 6:3). The Max. lipid of samples was measured 28.4%. Max. and min. protein of samples were 3.8% for T6 and 1.6% for T2 (FG/pectin ratio 2:1), respectively. No significant differences (p≥0.05) were observed between ash content of all treatments and control (commercial margarin). The acidity of treatments increased during storage and were significantly different from production day (p≤0.05). Peroxide value (PV) of treatments increased significantly at refrigerated storage. No significant differences were observed between PV of treatments during different wks of sampling. The results of texture profile analysis showed that firmness, compressibility and adhesiveness properties were significantly increase with higher substitution of FG with pectin. Color, Aroma, Taste and texture properties of prepared samples were found to significantly lower than control, according to sensory evaluation. Significant increases were observed in mold/yeast and psychrophilic count of treatments during storage. The macroscopic growth of molds was observed on all samples in 8th wks. No coliform growth was observed in all treatments at any time. Results suggest that low-fat spread properties were significantly influenced by different ratios of fish gelatin and pectin incorporated. It seems that these results can provide new opportunities to develop market with introducing novel products to response consumer demands. Some quality defects observed in this study can be improved by using suitable machinery at industrial scale
Cold pasteurization of rainbow trout fillet (Oncorhynchus mykiss) with gamma rays and shelf life assessment at refrigerated condition
The present study was conducted to evaluate the effect of different doses of gamma rays on shelf life and fatty acids composition of Rainbow trout fillet (Oncorhynchus mykiss) during refrigerating condition. Quality and shelf life of non-irradiated and irradiated (0, 0.75, 1.5, 2.25, 3, 3.75 and 4.5 kGy) Rainbow trout stored at +4 C was investigated by measurement of microbiological, chemical and sensory analysis .Irradiation of fillets was performed by gamma rays from a Co60 source. Microbial counts for non-irradiated trout fillet samples were higher than respective irradiated fish. Total volatile base nitrogen (TVB-N) values was increased from 7 mg/100 g for non-irradiated to 52.7 mg/100 g after 15 days storage at refrigerator, whereas for irradiated fish lower values of 39.4, 37.6, 28.7, 25.6, 24.8 and 23.2 mg/100 g were recorded at 0.75, 1.5, 2.25, 3, 3.75 and 4.5 kGy, respectively (day 15).initial amount of peroxide value in non irradiated sampleswas 0.8 meq/kg and was increased to 7 meq/kg (7 day).Highest amount of peroxide after irradiation process was belonged to samples irradiated by 4.5 kGy (1.5 meq/kg). Also, total viable count of irradiated samples were decreased significantly (p<0.05). On nutritional aspect, results showed that total saturated fatty acid concentrations increased significantly (p<0.001) with increasing irradiation dose , so that the control sample and fish muscles that irradiated with 4.5 kGy had the lowest and highest amounts of total saturated fatty acids (20.454 ± 0.011% and 19.228 ± 0.040% , respectively). The amount of total polyunsaturated fatty acids (PUFAs) in irradiated samples were significantly lower than control sample (p<0.001) and amounts of total monounsaturated (MUFAs) were significantly higher than control samples (p<0.001). The results were indicated that the highest content of MUFAs and PUFAs were in samples irradiated with 3.75kGy (37.783± 0.092 %) and control samples (37.677± 0.104 %), respectively .The lowest level of MUFAs and PUFAs were in control samples (36.596 ± 0.024%) and 4.5 kGy (36.459 ± 0.047%), respectively. Altogether, results of this study were determined that irradiation treatment changes significantly the fatty acid composition especially polyunsaturated fatty acids in rainbow trout muscle (P<0.001). Overall, irradiation of fillet by 3.75 kGy had best results on increasing shelf life of fillet at refrigerator (between 11-15 days) and had no advers effect on fatty acid composition of Rainbo trout fillet
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