264 research outputs found
Fillet quality grading of common carp (Cyprinus carpio) by fish size using mathematical equations
Quality grading and nutrition value determination of fish are nowadays necessary for aquatic processing. The present study was conducted to investigate a new, applied and cheap method of fillet quality grading for common carp (Cyprinus carpio) using fish size, based on mathematical equations. For this reason, 61 specimens of cultured market size carp were used and after filleting, their moisture, lipid, protein, energy and ash content were measured. Then, the relationships between proximate composition components of fillet and fillet length were studied. Results showed that there is an inverse linear regression relationship between logarithm of moisture content and logarithm of fish length (P0.05). Regarding the relationship between proximate composition of cultured carp fillets and fillet length machine fish sorting based on fish length and grading of moisture, lipid and energy content is feasible. We also found it feasible to determine type of processing and proximate composition of the prepared common carp
A New Robust Nonlinear Control Strategy for UIPC in Isolated Hybrid Microgrids
This paper focuses on the control of unified interphase power controller (UIPC) in isolated hybrid microgrids (HmGs), where the UIPC is used as the main component for interconnecting of AC and DC sub-grids. The investigated HmG encompasses two AC sub-grids and one purely storage DC sub-grid (PSDC) and multiple adjustable loads. A robust nonlinear model reference adaptive control (NMRC) strategy is offered for controlling the UIPC, keeping an acceptable two-way power exchange control with uncomplicated topology. Further, a novel configuration for the DC link power converter is suggested using the dual-active-bridge topology. Also, a harmonic-based modeling method is used to model the UIPC's power converter. The proposed configuration provides bidirectional power flow, increased power density, straightforward adaptation of zero-voltage switching, and direct access to cascading and parallelism to increase the ratings and reliability of UIPC. The simulation results illustrate the feasibility of the suggested topology for isolated HmGs
Free ultra-groups, generators and relations
In this paper, we intend to define an ultra-group by its presentation. The attitude of the presentation for a group was the key for us to investigate in this area. Instead of writing whole elements of an ultra-group, we denote it by its generators and the relations among those generators. A general computational approach for finitely presented ultra-groups by quotient ultra-groups and subultra-groups is described and some examples are presented. It is the way that can clarify the structure of an ultra-group quicker than having just a list of elements
Survey of nutritional and economic values of bighead (Hypophthalmichthys nobilis) in various sizes
Cultured fish are presented in various sizes and prices in market. The present study aimed to investigate the proportion of nutritional value and price of various weight groups of bighead (Hypophthalmichthys nobilis) and to offer two indices for comparing nutritional value in proportion with fish prices. For this purpose, bighead specimens were prepared in market sizes and their dry matter, lipid, protein and ash content and fillet yield were determined. Then, the proportion of nutritional and financial value (NP) and justified price difference based on dry matter content (PDdm) were calculated for each weight group. The results showed that the light weight group has a higher NP index for dry matter, protein, ash and energy than medium and heavy weight group. The NP index was the same between medium and heavy groups. While the price difference between light weight and two other weight groups is more than calculated PDdm index, the light weight group is a proper choice for purchase
Solution and Stability of a Mixed Type Cubic and Quartic Functional Equation in Quasi-Banach Spaces
We obtain the general solution and the generalized Ulam-Hyers stability of the mixed type cubic and quartic functional equation f(x+2y)+f(x−2y)=4(f(x+y)+f(x−y))−24f(y)−6f(x)+3f(2y) in quasi-Banach spaces
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