Calculation Of Diagrams Research Articles

Study on the Cleanliness of SWRS82B Hard Wire Steel Refined by Fluorine‐Free Slag with Medium and High Basicity

In order to apply and develop fluorine‐free slag in steelmaking, it is of great significance to study the effect of composition for fluorine‐free refining slag on the cleanliness of molten steel which affects its performance directly. The effect of composition of fluorine‐free refining slag with medium and high basicity on the contents of impurity elements for sulfur and oxygen, and characteristics of inclusions in SWRS82B hard wire steel, are investigated systematically. Sulfide capacity of refining slag is estimated based on the Royal Swedish Institute of Technology model. Dissolved oxygen content in molten steel equilibrated by refining slag is calculated based on Factsage software and classical thermodynamics. The calculated results are in good agreement with experimental results. The plasticity of inclusions at high temperature and low temperature is analyzed by phase diagram and Young's modulus calculation. The best cleanliness and inclusions of SWRS82B steel are obtained with slag composition of 53%CaO–19%SiO2–19%Al2O3–7%MgO, which has good melting characteristics. The impurity elements sulfur and oxygen in steel can be controlled for 26 and 19 ppm, respectively, and the average size of inclusions is 2.84 μm.

Perencanaan Strategi Pengembangan Usaha Menggunakan Formulasi Matrik SWOT dan Metode QSPM

This study aims to formulate appropriate marketing strategy planning alternatives through analyzing the approach of internal factors and external factors as an effort to face competitors from Aulia Jambi Toothpick Chips. The sampling method in this study was purposive sampling, so that the total sample obtained was 30 respondents consisting of 5 from internal, namely the management of the Aulia Toothpick Chips factory employees and 25 from external, namely consumers. The analysis method used in this research is SWOT analysis (Strength, Weakness, Opportunities, and Threats) through an internal and external factor approach with the calculation of the IFE and EFE matrix table analysis and the QSPM method. The results of IFE internal factors and EFE external factors, obtained a Strength value of 2.08 and Weaknesess of 1.08 while the Opportunities value is 1.92 and Threats is 1.38. Based on the results of the calculation of the analysis quadrant diagram using the IFE and EFE approaches, it can be concluded that the x, y axes are at the Quadrant I point, so the strategy that must be applied in this condition is to support aggressive growth policies (Growth Oriented Strategy). So that the right alternative strategy for Aulia's Toothpick Chips MSME players is the S-O (Strength-Opportunities) strategy. The S-O (Strength-Opportunities) strategy, which is referred to as an aggressive growth strategy, is through the use of digital marketing for the marketing system, providing special offers and maintaining product quality.

Enhancing growth speed of 3C–SiC using solution growth method by a new low temperature Mn-based cosolvent

Solution growth is a promising method for rapidly and stably preparing high-quality silicon carbide (SiC) single crystals. However, the coexistence of polycrystalline parasitism and solid inclusions during the growth of SiC in high-temperature solutions above 1800 °C still poses a serious threat to the quality of single crystals. Herein, we introduce an innovative Mn-based cosolvent for controlling the stable and fast growth of cubic-type silicon carbide (3C–SiC) single crystals at low temperatures. Firstly, our thermodynamic analysis reveals that SiC is the only stable solid compound in the low-temperature solution (1500–1600 °C) of the Si–Mn–C system, which is an important condition for the stable growth of crystals. Compared to typical solvents like Si–Cr, Si–Ti, and Si–Fe, the Si–Mn solvent exhibits the highest solubility and supersaturation for carbon. Secondly, our solubility calculations of SiC in the solvent show that the Mn-rich solvent can significantly increase the solubility of SiC. Thirdly, we successfully grew 3C–SiC single crystals from Si–Mn solution at 1500 °C without other SiC polymorphs produced. Rapid growth of SiC crystals in Mn-rich solution was achieved by modulating the content of Mn. Our work highlights the superiority of Si–Mn cosolvents in facilitating rapid growth of 3C–SiC single crystals at low temperatures. It introduces a novel approach by applying phase diagram calculation techniques to design suitable solvent systems for the solution growth of SiC single crystals.

Combining Thermodynamics and Kinetics to Investigate the Corrosion of 3Cr Steel and HP-13Cr Stainless Steel in Extreme Oil-Gas Environments

ABSTRACT The corrosion behavior of 3Cr steel and HP-13Cr stainless steel (SS) under high temperature and CO2 or H2S pressure environments was investigated by immersion tests and multiple characterizations of corrosion films, and analyzed by combining the Pourbaix diagram and kinetic calculations. At 180 °C/3.8 MPa CO2, both 3Cr steel and HP-13Cr SS exhibited double-layered corrosion films, comprising a crystalline FeCO3 outer layer and an inner Cr2O3 and Cr(OH)3 layer. Furthermore, at 180 °C/3.8 MPa H2S, the corrosion films of both steels consist of an outer crystalline pyrrhotite and pyrite layer and an inner Cr2O3 and Cr(OH)3 layer. The corrosion resistance of 3Cr in H2S is inferior to that of HP-13Cr SS due to the influence of stress corrosion cracking but is close to that of HP-13Cr SS in CO2. Therefore, 3Cr steel could be considered a cost-effective alternative to HP-13Cr SS in CO2 environments.

Research on the Soft-Sensing Method of Indicator Diagram of Beam Pumping Unit.

An accurate calculation of the indicator diagram of a pumping unit is the key factor in analyzing the performance of an oilfield production and operation and in preparing and optimizing an oilfield development plan. Aiming at the problems of the poor stability of the conventional load-displacement sensor method and the wave equation method, owing to the influence of an alternating load on the force sensor and the difficulty in measuring the crank angle using the electrical parameter method, a new soft sensing method employing the input electrical parameters of the motor and the beam inclination has been proposed to obtain the indicator diagram. At first, this method is established based on the beam angle of the pumping unit, which is easily measured using the suspension point displacement mathematics calculation model and the torque factor. Subsequently, the electric motor input parameters, the parameters of the four-bar linkage, and the relationship between the polished rod load have been established. Finally, the motor and the beam angle of the measured electrical parameters have been substituted into the calculation of the suspension point displacement and load value and pull in accordance with the guidelines to eliminate the singularity mutation values. After processing the measured data through a Butterworth filter, the indicator diagram is obtained. The results of the engineering experiment and application show that the average relative error of the method is less than 3.95%, and the maximum relative error remains within 2% for 6 months, which verifies the stability of the soft sensing method.

Biological Activities and Chemical Compositions of Prangos platychlaena Boiss. Essential Oil and Fractions, Multivariate Statistical Analyses.

In this research, essential oil was obtained from the aerial parts of Prangos platychlaena Boiss. by hydrodistillation using a Clevenger-type apparatus, separated into fractions having different polarities by column chromatography. Both essential oil and the fractions were analyzed by GC-FID and GC/MS simultaneously. Nona-3,5-diyne-2-yl acetate (46%) and 3,5-nonadiyne (13.5%) were found to be the main constituents of the essential oil. While the main components of the n-hexane fraction were characterized as 3,5-nonadiyne (45.6%) and germacrene B (16.4%), the major components of the methanol fraction were found to be nona-3,5-diyne-2-yl acetate (59.6%) and 3,5-nonadiyne-2-ol (25.9%). In addition, principal multivariate statistical analyses were performed with principal component analyses and Venn diagram calculations, utilizing chemical compositions of the essential oil and the fractions. Furthermore, in vitro anti-inflammatory activities of the essential oil and the fractions were evaluated to correlate the chemical composition with the biological activity, and to the best of our knowledge, this study was performed for the first time in this aspect. LOX inhibitions of the essential oil, n-hexane, and methanol fractions were determined to be 70.98 ± 1.7, 67.10 ± 2.5, and 50.11 ± 4.8%, respectively. Preliminary initial findings of this study will be extended in the future with new biological assays.

Calculation of phase diagram and the thermodynamic quantities by the Landau mean field model close to the solid – liquid and solid – solid transitions in n-paraffins

ABSTRACT We calculate the phase diagrams and predict the temperature dependence of the thermodynamic quantities at high pressures for the solid – liquid and solid – solid transitions in n-paraffins. This calculation is performed by fitting the phase line equations as obtainedfrom the Landau model to the experimental data from the literature. On thebasis of the Landau model, phase diagram of the solid – solid transition ispredicted at 0.1 MPa for the binary mixtures of n-tridecane + (n-hexane and cyclohexane).For the calculation of the heat capacity the extended mean field is employedfor the n-paraffins studied here. We find that our calculated phase diagrams explain the observed behaviour of the liquid – solid transitions at high pressures in those binary mixtures. Our phase diagrams predicted at 0.1 MPa and our predictions for the thermodynamic quantities can be compared with the experiments for those binary mixtures.

Solute Effects on Growth Restriction in Dilute Ferrous Alloys

The effect of dilute solute additions on growth restriction in binary ferrous alloys has been assessed by means of the heuristic growth restriction parameter (β) modelling framework (Fan et al. in Acta Mater. 152, 248–257, 2018). The CALPHAD (CALculation of PHAse Diagrams) methodology (Kaufman and Bernstein in Computer Calculation of Phase Diagrams, 1970) has been used to calculate β values from the liquidus slope m and the equilibrium distribution coefficient k values, at first approximation, in conjunction with the liquid-to-solid fraction to obtain true β values. Critical solute concentrations, below which solidification becomes partitionless, have also been calculated. Among 23 dilute binary ferrous alloy systems investigated, the five most efficient solutes on grain refinement are B, Y, O, S and C. A negative correlation, or inverse relationship, was observed between the true β values and the grain size values obtained from a study on experimental multicomponent dilute ferrous alloy systems (Li et al. in Metall. Mater. Trans. A 49 A, 2235–2247, 2018).

Application of CALPHAD Method for Predicting of Concentration Range of Amorphization of Transition Metals Melts

Early, the efficiency of the CALPHAD (Calculation of Phase Diagrams) method to a targeted search for compositions of amorphous alloys has been shown. The method for predicting the ranges of amorphization is based on the calculation of diagrams of metastable phase transformations between supercooled melts and boundary solid solutions on the base of pure elements. In this work, the model parameters for thermodynamic properties of liquid alloys and boundary solid solutions were summarized in a self-consistent database for the multicomponent Cu–Fe–Ni–Ti–Zr–Hf system. Such database for the multicomponent system is based on a common set of model parameters for boundary binary and ternary systems. This database was used to predict the concentration ranges of amorphization for the quinary Cu–Fe–Ni–Ti–Zr, Cu–Fe–Ni–Ti–Hf and boundary ternary and quaternary systems. The results of calculations are presented along sections in quaternary and quinary systems. The ternary and quaternary equiatomic alloys along with high entropy CuFeNiTiZr and CuFeNiTiHf alloys are trapped into prognosed composition ranges of amorphization. Predicted composition space of amorphization for melts of the Fe–Ni–Ti–Zr system is shown on the concentration tetrahedron. Based on the obtained results, a new criterion for predicting the concentration regions of amorphization of multicomponent melts is proposed, according to which the presence of a sufficient content of metals that are electron acceptors and donors is a chemical factor that affects the thermodynamic stability of melts and determines their glass-forming ability. For multicomponent melts of the Cu–Fe–Ni–Ti–Zr–Hf system the concentration ranges of amorphization correspond to the simultaneous fulfillment of the conditions xFe + xNi + xCu > 0.25 and xTi + xZr + xHf > 0.15, where Fe, Ni, and Cu are electron acceptors and Ti, Zr, and Hf are electron donors.

Experiment and first-principles calculation to investigate the phenomenon of Gd and Y elemental enrichments in the long-period stacking ordered phase

In this study, the Gd and Y elemental enrichment in long-period stacking ordered (LPSO) phases has been systematically studied by combining energy dispersive X-ray spectrometry (EDS) diagram and first-principles calculation. This phenomenon differs from the ordinary type of LPSO phase, which consists of only one rare earth element. It is highly likely that the observed effect is attributed to the preferential formation of the Mg-Y-Zn LPSO phase, which is subsequently replaced by the Gd element to form more stable Mg-Gd-Y-Zn LPSO phases. The results of the formation enthalpy and energy suggest that the most probable situation is one group of Gd (four atoms) replacing the Y atoms. The electronic properties and elastic properties were performed to investigate the bonding character and mechanical stability. It can be found that the substitutional doping of the Gd element is able to improve bonding strength and increase anisotropy. Therefore, this research explains the interesting phenomenon of Gd and Y elemental enrichment for in-depth understanding of LPSO phases, and provides valuable data that can be utilized for designing rare-earth magnesium alloys with improved properties.

An advanced theoretical approach to study super-multiperiod superlattices: theory vs experiments

A new theoretical method to study super-multiperiod superlattices has been developed. The method combines the precision of the 8-band kp-method with the flexibility of the shooting method and the Monte Carlo approach. This method was applied to examine the finest quality samples of super-multiperiod Al0.3Ga0.7As/GaAs superlattices grown by molecular beam epitaxy. The express photoreflectance spectroscopy method was utilized to validate the proposed theoretical method. For the first time, the accurate theoretical analysis of the energy band diagram of super-multiperiod superlattices with experimental verification has been conducted. The proposed approach highly accurately determines transition peak positions and enables the calculation of the energy band diagram, transition energies, relaxation rates, and gain estimation. It has achieved a remarkably low 5% error compared to the commonly used method, which typically results in a 25% error, and allowed to recover the superlattice parameters. The retrieved intrinsic parameters of the samples aligned with XRD data and growth parameters. The proposed method also accurately predicted the escape of the second energy level for quantum well thicknesses less than 5 nm, as was observed in photoreflectance experiments. The new designs of THz light-emitting devices operating at room temperature were suggested by the developed method.

Corrosion resistance investigation of the Ti–Al–Mo system supported by CALPHAD approach and key experiments

The corrosion resistance of Ti–Al–Mo alloys in seawater were investigated by thermodynamic calculations and electrochemical tests. Four as-cast alloys were designed based on thermodynamic calculations. The calculated results were verified by experimental determination. The Gibbs energy and electrochemical experiment results showed Ti55Al40Mo5 alloy has the most positive Gibbs energy and the best corrosion resistance. The bcc(Ti) phase has best corrosion resistance among AlTi, AlTi3 and bcc(Ti). The present work further proves the important role of phase diagram calculation in alloy design, and thermodynamic database provides important theoretical support for efficient development of new alloys.

A toolbox approach to revealing a series of naphthocarbazoles to showcase photocatalytic reductive syntheses.

The development of highly reducing photocatalysts to functionalize arenes via the generation of reactive aryl radicals under mild and environmentally benign reaction conditions has emerged as a noteworthy approach in the realm of organic synthesis. Herein, we report a readily synthesized series of novel naphthocarbazole derivatives (NCs) as organo-photocatalysts, which, upon irradiation under 390 nm light, acquire high reducing power to catalyze several reductive transformations. The promising properties revealed by in depth photophysical and electrochemical studies ( = -1.9 V to -2.07 V vs. SCE, τ = 5.59 to 7.12 ns) demonstrate NCs to be versatile catalysts, and notably, rational variation of the substituents (NC1-NC6) modulates their success as efficient photoreductants. Detailed DFT calculations of the frontier MO diagrams and energy levels revealed them to be non-donor-acceptor type molecular scaffolds. The applicability of the NCs as catalysts was demonstrated in reductive dehalogenative borylation, phosphorylation, and dehydrohalide intramolecular C-C coupling reactions, as well as the dimerization of carbonyls and imines. Visible-light-irradiated selective reductive desulfonylation from heteroaromatics and peptides further enhances their synthetic utility.

Influence of Si contents on the microstructure and corrosion resistance of the Zn−Al−Mg−Si alloys

Hot dip galvanized products are widely used in various aspects of production and life due to their excellent corrosion resistance. Some studies have added a fourth trace alloying element to the zinc aluminum magnesium coating to form a quaternary alloy for better performance. This article prepared two different types of Zn−Al−Mg alloy ingots with trace amounts of Si added by induction melting, consisting of Zn1Al1Mg0.01Si and Zn1Al1Mg0.05Si, and solidified them in a heating furnace with argon gas protection atmosphere. The precipitation process of Zn1Al1Mg(0.01,0.05)Si alloy components under non equilibrium and equilibrium solidification conditions was calculated. The initial crystalline phase of the alloy and the initial solidification temperature were predicted through phase diagram calculations. The microstructure and phase types of the alloy were analyzed using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM). The electrochemical Tafel curves of Zn1Al1Mg(0.01,0.05)Si with different Si contents showed that the Zn1Al1Mg0.05Si has the highest corrosion potential and Zn1Al1Mg0.01Si has the lowest corrosion current which means the 1Al1Mg0.01Si alloy possesses the highest corrosion resistance. The Nyqust curves and bode curves also showed that the practical impedance of 1Al1Mg0.01Si alloy is higher than that of 1Al1Mg0.05Si. Moreover, electron probe X-ray micro-analyzer(EPMA) reveals the distribution of Si elements in the Zn1Al1Mg(0.01,0.05)Si. At present, there is little research on the microstructure and properties of quaternary alloys containing silicon. Therefore, studying the influence of silicon content on the microstructure and properties of alloys is of great significance.

Study on Softening Resistance of Cu-Sn-Fe-P alloy for Advanced Electrical Connectors

The effect of adding iron element in tin bronze on the microstructure and properties of Cu-Sn-Fe-P alloy is studied by means of phase diagram calculation and microstructure observation. The work hardening curve of Cu-Sn-Fe-P alloy is plotted by cold deformation of the alloy with different reduction rates. The test and microstructure observation are conducted for tensile strength and ductility of the alloy sample annealed at different temperatures, so as to determine the recrystallization temperature of the alloy. The results show that the addition of iron element plays a significant role in grain refinement and improves the subsequent working performance. After the cold rolling deformation, an obvious work hardening effect is imposed on the alloy. With the increase of the deformation, the alloy presents a trend of increasing first and then becoming stable in the tensile strength, while a reverse trend in ductility. Cu-Sn-Fe-P alloy has a softening resistance equivalent to that of QSn6.5-0.1 high-tin bronze, both of which will be softened at 400ºC; therefore, Cu-Sn-Fe-P alloy can replace QSn6.5-0.1 alloy at high temperature.The present study proposes how to maintain the original properties of the tin-phosphorous bronze alloy while reducing the content of the tin, and achieve the more effective industrialized production.

Optimization Design of Phononic Crystals Based on BPNN‐MPA in Applied Mathematical Analysis

Traditional finite element analysis methods have the problem of expensive and unstable band structure diagram calculation when generating phononic crystals. Therefore, this study combines back propagation neural networks with ocean predator algorithms to optimize the geometric structure of phononic crystals. The results show that the coefficient of determination for the predicted bandgap width and lower bound of Model 3 is 1.00, which is better than the comparison model. However, Models 2 and 5 have poor predictive performance for bandgap width due to overfitting during actual training. Therefore, after using the ocean predator algorithm for hyperparameter adjustment, it is found that the maximum number of failures in the validation set of Model 5 is 30, the number of hidden layer nodes is 30, and after 500 experiments, the average error of the bandgap width is 5.26%, and the average error of the lower bound of the bandgap is 1.33%. The average error of the bandgap width after hyperparameter adjustment is 4.89%, and the average error of the lower bound of the bandgap is 1.21%, both of which are effectively reduced and better than the comparison model. Overall, the combination model has high computational efficiency and stability in phononic crystal optimization and can be practically applied in the design and optimization of phononic crystal geometric structures.

Сравнение методов исследования терморадиационного режима производственных помещений и воздействия теплового излучения на работников

The thermoradiational situation in the steelmaking shop and at the aluminum casting site was investigated. The calculation of the heat radiance of a steelworker and a forklift operator of metallurgical production is carried out in two ways. The first method involves the engineering calculation of heat radiation and the construction of its plot in two-dimensional and three-dimensional space, based on data on the temperatures of radiation sources, the distances from them to the irradiated objects, the angles between the normal to the sources and the directions to them and the degree of blackness of radiation sources. For a workplace located in a volume limited by walls, the degree of blackness of the wall material was additionally considered. The second method involves mathematical and computer modeling. A numerical model implemented in the ANSYS finite element modeling program was used. A mathematical model of radiation based on the Discrete Ordinates method was used to display thermal processes. When comparing the results of the calculation of heat emission by two methods, it was revealed that the relative error of the diagram calculation method in two-dimensional space compared to modeling averaged 34.9 %, in three-dimensional — 22.5 %. This is due to the fact that when calculating by the diagram method, radiation sources and irradiation objects (in a two-dimensional formulation), as well as the radiating surface of sources (in a three-dimensional formulation) are considered not as three-dimensional objects (as in modeling), but as point objects, which effects the accuracy of the method.

Effect of Alloying Compositions on the Stacking Fault Energy and Elasticity of FeNiCrAlCo and FeNiCrAlCu: A First-principles Study for Fe-based High Entropy Superalloy Design

High Entropy Superalloy (HESA) is a classification of materials with promising properties extensively developed to improve performance, resource sustainability, and cost efficiency in high-temperature applications. The need for computation on HESA is due to its time and cost superiority over experiments while maintaining good accuracy. However, thermodynamic data of some rare elements like Zr has not existed in publications based on a phase diagram calculation. First-principles is then used to investigate further the effect of decreasing Ni while adding Cu and Zr on lattice parameters, elasticity, stacking fault energy (SFE), and electronic structure of Fe-based HESA FeNiCrAlCo and FeNiCrAlCu. Adding Cu increases the SFE and ductility while decreasing Ni and adding Zr decreases the SFE and increases the strength but slightly reduces the ductility. Electronic structure analysis showed that adding Zr increases charge accumulation and decreases density of states, then interatomic bonding weakened, interlayer distance increased, and SFE decreased. The Fe-based HESA design can be optimized by reducing Ni concentration and increasing Cr concentration to decrease SFE to significantly increase strength, ductility, and hardness, especially at high temperatures, or adding Zr to decrease SFE value to the maximum. This study will help develop low-cost high entropy superalloys with desired performance.

Effects of Si Content on the Growth of Oxide Layers in Carbon Steels during the Heating Process

A prevalent metal surface defect is hot-rolled iron oxide; thus, it is critical to regulate the production and growth of oxidized iron during the hot-rolling process. To analyze the influence of Si content on the growth laws of the oxidized layer in carbon steel during heating, three types of carbon steel with significant differences in Si content were selected for research on the growth laws of the oxidized layer at different heating temperatures. The production law and micromorphology of the oxidized layer were analyzed using methods such as scanning electron microscopy and thermodynamic phase diagram calculation, and an oxidation dynamic model was obtained. The predicted control values of the model are highly consistent with the measured values. This study reveals that the heating temperature significantly impacts the thickness of the oxidized layer of carbon steel. At temperatures below 500 °C, the oxidation is not evident, and the layer is thin. Between 500 °C and 900 °C, the steel’s composition affects the thickness. Carbon steels with high Si content form a dense iron olivine layer, which slows down the oxidation rate. However, heating temperatures above 900 °C cause the protective oxidized film to reach the melting point of iron olivine, increasing the oxidation rate. At 1200 °C, the oxidized layers of the three types of carbon steel remain consistent. This paper’s research findings offer theoretical guidance for large-scale industrial production practices and serve as a reference for similar studies on steel oxidation behavior.

Design and calculation of cold storage capacity of 10 tons for tuna commodity

The Ministry of Maritime Affairs and Fisheries, Republic of Indonesia, urges economic stakeholders to maximize increasingly open export opportunities. With an abundance of fishery products in Indonesian waters, it must be supported by adequate facilities, one of which is the availability of cold storage, which maintains the quality of fishery products. In this study, the design of the cold storage was carried out by measuring the size of the cold storage and using the calculation of the cooling load, the calculation of cooling capacity, the calculation of the P-h diagram, and the cost estimate. The results of this study include cold storage design dimensions of 420 m3 with a long length and tall of 15×7×4 m3 made from insulation materials of polyurethane, stainless steel, and plaster. The cooling load data for the cold storage, when the product (tuna) is cooled and filled, is 3,707,444.3 kJ every 24 hours. A ton of refrigeration absorbs 12,660 kJ per 24 hours, equaling 16.3 tons of required refrigeration capacity. Meanwhile, under normal operating conditions, the total cooling load is 759,427.588 kJ per 24 hours. After calculating the cooling load, it was discovered that the initial design, which only had a capacity of 10 tons during the refrigeration process, could accommodate a cooling capacity of up to 16.3 tons. The cooling capacity of cold storage is 23.9 kW or 81.400 Btu/h. P-h diagram calculation of compressor cooling load is 0.7 kW, and the cooling load total from the evaporator to keep air room temperature of cold storage 0 °C is 0.43 kW. Estimated cost total for materials of cold storage design is USD 128,655. Highlights Refrigerator facilities are still limited in reaching remote coastal areas The cooling system must start using renewable energy Cold storage is used to maintain the quality of fishery product so that they remains in good condition From the calculation results, knowing the total cooling load when the cold storage is working, knowing the total cooling capacity of the cold storage when it is used as a fish storage refrigerator, and knowing the total estimated operational costs of the cold storage