315 research outputs found
Effect of carboxymethyl cellulose-based coatings incorporated with Zataria multiflora Boiss. essential oil and grape seed extract on the shelf life of rainbow trout fillets
To prolong the shelf life of seafood products, lipid oxidation and growth of microorganisms should be retarded. The objective of the current study was evaluating the potential application of carboxymethyl cellulose (CMC) coatings incorporated with Zataria multiflora Boiss. essential oil (ZMEO) and grape seed extract (GSE) on chemical (thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVB-N)), microbial (total viable count, lactic acid bacteria and Pseudomonas spp.) and organoleptic attributes of rainbow trout fillets during refrigerated storage for twenty days. GCeMS analysis showed that ZMEO is rich in monoterpene phenols such as thymol and carvacrol. The following results were obtained after 20 days of storage: The minimum level of TVB-N was measured in the fillets coated with CMC + 2 v/v ZMEO + 0.5 v/v GSE. The minimum number of total viable bacteria, lactic acid bacteria and Pseudomonas spp. were determined in the fillets coated with CMC + 2 v/v ZMEO + 1 v/v GSE. The fillets coated with CMC + 1 v/v ZMEO + 1 v/v GSE showed the best organoleptic properties. Our results revealed that CMC-based coatings incorporated with ZMEO and GSE could improve chemical, microbial and sensorial characteristics of rainbow trout fillets during cold storage. © 2015 Elsevier Ltd
The virial theorem and exact properties of density functionals for periodic systems
In the framework of density functional theory, scaling and the virial theorem
are essential tools for deriving exact properties of density functionals.
Preexisting mathematical difficulties in deriving the virial theorem via
scaling for periodic systems are resolved via a particular scaling technique.
This methodology is employed to derive universal properties of the
exchange-correlation energy functional for periodic systems.Comment: Accepted in PRB(R) 201
Tuning independently Fermi energy and spin splitting in Rashba systems: Ternary surface alloys on Ag(111)
By detailed first-principles calculations we show that the Fermi energy and
the Rashba splitting in disordered ternary surface alloys (BiPbSb)/Ag(111) can
be independently tuned by choosing the concentrations of Bi and Pb. The
findings are explained by three fundamental mechanisms, namely the relaxation
of the adatoms, the strength of the atomic spin-orbit coupling, and band
filling. By mapping the Rashba characteristics,i.e.the splitting and the Rashba
energy, and the Fermi energy of the surface states in the complete range of
concentrations. Our results suggest to investigate experimentally effects which
rely on the Rashba spin-orbit coupling in dependence on spin-orbit splitting
and band filling.Comment: 11 pages, 3 figure
Suitable coating material for microencapsulation of spray-dried fish oil
This study was conducted to screen the most suitable coating material for the production of microencapsulated fish oil powder using ternary blends of maltodextrin (15, 25 % w/w), Arabic gum (2.5, 7.5 % w/w), and methylcellulose (0.5, 1.5 % w/w). The physical properties of fish oil emulsion and encapsulated powders were evaluated. Arabic gum (5 % w/w) showed the most significant (p < 0.05) effect on the surface mean diameter of the droplets in the emulsion. Maltodextrin had the most significant (p < 0.05) effect on the centrifuge stability of the emulsion and the amount of surface oil of the powder at 15 and 20 % (w/w) respectively, whereas methylcellulose (0.5 % w/w) had the most significant (p < 0.05) effect on the width distribution of the droplets in the emulsion. The total optimal area leading to the formation of coating material with desirable physical properties was expected to be obtained by the combination of 16 % (w/w) maltodextrin, 6.5 % (w/w) Arabic gum, and 0.88 % (w/w) methylcellulose respectively
A Review on Ethnobotanical and Therapeutic Uses of Fenugreek (Trigonella foenum-graceum L)
Fenugreek with the scientific name of Trigonella foenum-graceum L and with leaves consisting of 3 small obovate to oblong leaflets is an annual herbaceous plant of the Fabaceae family. It is native to the eastern Mediterranean but is cultivated worldwide. This plant has medicinal alkaloids, steroid compounds, and sapogenins and many uses have been mentioned for this plant in traditional medicine. This plant has been used to ease childbirth, to aid digestion, and as a general tonic to improve metabolism. Trigonelline is considered as the most important metabolite of fenugreek, which is very effective in treating diabetes and decreasing blood cholesterol. Diaszhenin is another important compound in seeds of this plant, which is used in producing medicinal steroids like contraceptive pills. Many studies have been performed on the therapeutic effects and identification of chemical compounds of this plant. In this article, the most important biological effects and reported compounds about fenugreek seed are reviewed and its therapeutic applications are investigated. © 2015, © The Author(s) 2015
VALUATION OF GROUNDWATER EXPLOITATION OF AGRICULTURAL CASE STUDY OF WHEAT FARMERS IN KHATAM CITY
Country with an annual average rainfall of 250 mm is faced with the problem of dehydration and non-uniform distribution of water resources. Scarcity of water on the one hand, and the enormous costs on the other hand, is considered productivity and economic value of water as one of the most important national goal. Consumption of Water in agricultural sector includes about 90 percent of the country´s water consumption, so the economic value of water in agriculture is one of the most important priorities in water resources management. In this study the economic value of water by considering methods of calculate, methods based on basic function of social welfare witch economic value of water for production of Wheat in Yazd (Heart - khatam) was analyzed required data and information is collected from 100 questionnaires using two-stage cluster sampling in 1387. For estimation of functions is used from Eviews5 software. The results show decreasing scale in the region. Also marginal production of factors so that water, labor and pesticides evaluated respectively 1.4, 65 and 1113 kg per unit. Producers are willing to sacrifice to 0.228 unit of labor (or sacrifice to 0.0067 unit of pesticides). Marginal production-factor price ration for water, labor and pesticides are 0.0049, 0.0005 and 0.0159 respectively. Actual results (economic) value of water is 12,593 Rials witch difference significantly with current value (277.4 Rials) in region that leading to excessive withdrawal of groundwater water in region. The shadow price of labor and pesticides are 604,500 and 10,350,900 Rials respectively. Price and income elasticity of water derived demand are 15.33 and 45.329 respectively. JEL Classifications : C13, C20, D21, Q11, Q25, Q34. Key words: Cobb Douglas production function, economic value, efficiency to scale, demand elasticity, Yazd province, Khatam-Hear
Revisiting the Core and Cover of Quality in Higher Education
Member states of the Organization of Islamic Conference (OIC) have committed themselves to promote a program of action to improve and reform their educational institutions and curricula on the basis of the "OIC Vision 1441". As part of this commitment, a process has been initiated to review current international university ranking systems and to create a specific mechanism for ranking universities of the OIC countries. In this study, we explore the criteria that emerged as an outcome of this process and have been adopted for the purpose of ranking OIC universities. We raise the challenge that, although the idea of an OIC-specific ranking mechanism is a potentially valuable initiation for the Islamic countries to converge and cooperate, the whole endeavor tends to deal only with rudimentary issues in science, education, and research. The core conceptions, taken for granted and almost left untreated, continue to exist under the disguise of the newly fabricated criteria. For each one of the five major sets of criteria (Research, Education, International out-look, Facilities, and Socio-economic impact) we discuss why we believe they deal with the 'cover' rather than the 'core' of quality in higher education and research. We further discuss that truly alternative practices in the context of specific socio-cultural values, require revisiting underlying and taken for granted understandings of science, research, and technology. To walk our own way and to challenge the dominant mainstream global forces, we need a fundamentally alternative view of the quality and value of knowledge and basically of the value of the human being
Two-dimensional optomechanical crystal cavity with high quantum cooperativity
Optomechanical systems offer new opportunities in quantum information processing and quantum sensing. Many solid-state quantum devices operate at millikelvin temperatures—however, it has proven challenging to operate nanoscale optomechanical devices at these ultralow temperatures due to their limited thermal conductance and parasitic optical absorption. Here, we present a two-dimensional optomechanical crystal resonator capable of achieving large cooperativity C and small effective bath occupancy n_b, resulting in a quantum cooperativity C_(eff) ≡ C/n_b > 1 under continuous-wave optical driving. This is realized using a two-dimensional phononic bandgap structure to host the optomechanical cavity, simultaneously isolating the acoustic mode of interest in the bandgap while allowing heat to be removed by phonon modes outside of the bandgap. This achievement paves the way for a variety of applications requiring quantum-coherent optomechanical interactions, such as transducers capable of bi-directional conversion of quantum states between microwave frequency superconducting quantum circuits and optical photons in a fiber optic network
Fingerprints Indicating Superior Properties of Internal Interfaces in Cu(In,Ga)Se2 Thin-Film Solar Cells
Growth of Cu(In,Ga)Se2 (CIGS) absorbers under Cu-poor conditions gives rise to incorporation of numerous defects into the bulk, whereas the same absorber grown under Cu-rich conditions leads to a stoichiometric bulk with minimum defects. This suggests that CIGS absorbers grown under Cu-rich conditions are more suitable for solar cell applications. However, the CIGS solar cell devices with record efficiencies have all been fabricated under Cu-poor conditions, despite the expectations. Therefore, in the present work, both Cu-poor and Cu-rich CIGS cells are investigated, and the superior properties of the internal interfaces of the Cu-poor CIGS cells, such as the p-n junction and grain boundaries, which always makes them the record-efficiency devices, are shown. More precisely, by employing a correlative microscopy approach, the typical fingerprints for superior properties of internal interfaces necessary for maintaining a lower recombination activity in the cell is discovered. These are a Cu-depleted and Cd-enriched CIGS absorber surface, near the p-n junction, as well as a negative Cu factor (∆β) and high Na content (>1.5 at%) at the grain boundaries. Thus, this work provides key factors governing the device performance (efficiency), which can be considered in the design of next-generation solar cells
- …