• The Korean Journal of Mycology
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• v.30 no.1
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• pp.18-22
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• 2002

This study was carried to investigate efficient pot diameter and substrate weight in pot cultivation of Pleurotus ostreatus. Cultivating substrate was pine sawdust+beet pulp+cotten seed flour (50 : 30 : 20, v/v). Ranges of pot diameter and substrate weight were $10{\sim}20\;cm\;and\;600{\sim}2,500\;g/pot$, respectively. Smaller pot diameter resulted in longer pot length according to increasing substrate weight, so mycelial growth period and total cultivation period was retarded. Wider pot diameter resulted in a little lower biological efficiency in the same substrate weight. Heavier substrate weight was brought higher yield but lower biological efficiency. Average yield according to pot diameter was decreased at wider than 14 cm during second flush. And average biological efficiency according to substrate weight was lower than 100% at heavier than 1,200 g/pot during second flush. So suitable pot diameter and substrate weight in pot cultivation of Pleurotus ostreatus were estimated $10{\sim}14\;cm\;and\;800{\sim}1,200\;g$, respectively.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.27-36
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• 2021

A capacitive water sensor was developed to measure the capacitance over a wide part of a substrate using an insulated electrode plate (30 cm × 10 cm) with copper and Teflon attached on either side of the substrate. This study aimed to convert the capacitance output obtained from the condenser-type capacitance sensor into the substrate water content. The quantification experiment was performed by measuring the changes in substrate water weight and capacitance while providing a nutrient solution and by subsequently comparing these values. The substrate water weight and capacitance were measured every 20 to 30 seconds using the sensor and load cell with a software developed specifically for this study. Using a curve-fitting program, the substrate water content was estimated from the output of the capacitance using the water weight and capacitance of the substrate as variables. When the amount of water supplied was increased, the capacitance tended to increase. Coefficient of variation (CV) in capacitance according to the water weight in substrate was greater with the 1.0 kg of water weight, compared with other weights. Thus, the fitting was performed with higher than 1.0 kg, from 1.7 to 6.0 kg of water weight. The correlation coefficient between the capacitance and water weight in substrate was 0.9696. The calibration equation estimated water content from the capacitance, and it was compared with the substrate water weight measured by the load cell.

• Mycobiology
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• v.36 no.3
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• pp.157-160
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• 2008

This study was carried out to determine the possibility of bottle cultivation utilizing recycled oyster mushroom culture waste as a cultivating substrate for P. ostreatus. Total nitrogen percentage was 0.76%, 1.13%, 1.16%, 1.36%, and 1.38% in the 1-, 2-, 3-, 4-, and 5-time mixed substrate, respectively; 0.95%, 1.04%, 1.34%, 1.36%, and 1.25% in the 1-, 2-, 3-, 4-, and 5-time postharvest substrate, respectively; and 0.72% and 0.68% in the 2- and 3-time nonadditive substrate, respectively. Weight of the fresh fruiting body harvest was 115 g, 120 g, 117 g, 118 g, and 114 g on 1-, 2-, 3-, 4-, and 5-time mixed substrate, respectively; and 105 g and 45 g on 2- and 3-time nonadditive substrate, respectively. The first mixed substrate (fresh) and recycled substrates generated no significant difference in the weight of fresh fruiting bodies harvested.

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.2
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• pp.139-149
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• 1999

Thermal sprayed Ni-Cr alloy coating on the carbon steel was carried out erosion-corrosion test and electrochemical corrosion test in the marine environment. The erosion-corrosion behavior and electrochemical corrosion characteristics of substrate(SS400) and thermal sprayed Ni-Cr coating was investigated. The erosion-corrosion control efficiency of Ni-Cr coating to substrate was also estimated quantitatively. The main results obtained are as follows : 1) The weight loss rate of Ni-Cr coating layer by the erosion-corrosion compared with substrate was smaller. With the lapse of time, the weight loss rate of substrate was linearly increased in $25{\Omega}{\cdot}cm$ solution, but that of Ni-Cr coating became stable. 2) The corrosion potential of substrate became less noble than that of Ni-Cr coating layer, and the corrosion current density of Ni-Cr coating became lower than that of substrate. 3) The control efficiency of erosion-corrosion of Ni-Cr coating compared to substrate became more dull than that of corrosion in $25{\Omega}{\cdot}cm$ and $5000{\Omega}{\cdot}cm$ solution.

• Journal of the Korean Ceramic Society
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• v.36 no.9
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• pp.991-996
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• 1999

Effect of solution property on the weight varation and microstructural change of film was studied by electrophoretic deposition in order to obtain a homogeneous and dense zirconia film. As a result of weight kinetics of film which obtained in alcohol or aqueous solution having different polarity experimental data showed large deviation from theoretical ones calculated by Zhang's kinetic model. It had been shown that the weight affecting factors was largely dependent on properties other than dielectric constant and viscosity of solvent zeta potential appiled field and time. In initial stage a main factor of the drastic weight increase was the capillary drag of porous substrate. The cause of weight decrease with time in aqueous solution after 300 s was attributed to the defect of film by sagging and electrolytic reaction. The electrolyte film which prepared in alcohol solution with good wetting for substrate had better homogeneous and dense microstructure than one in aqueous solution with high surface tension.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1221-1231
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• 2015

The present study was conducted to find a way to recycle the coir substrate by investigating changes in its physical and chemical properties based on the number of use year. Specific gravity of unused coir substrate was $0.212g/cm^3$, while it was higher for the substrate used for 2 years. Porosity was different depending on the number of use year. The porosity of unused substrate was 51.9%, but it increased to 68.6% after used for 2 years. In general, physical and chemical properties were better in the coir substrate used for 2 years than in unused one. The number of leaves, leaf area, flesh weight and dry weight of oriental cabbage and lettuce were higher in coir substrate used for 2 years than those in unused one. Whereas, no significant difference was observed between the substrates used for one year and 2 years, indicating that the one time-used wast substrate could be recycled for cultivating vegetables. Growth of the vegetables was improved when organic fertilizer composed of complex organics with different mixing ratios was provided to the coir substrate, compared to untreated plot. The optimum mixing ratio of the wast substrate and complex organics was 2:8(v/v) for fertilization using wast coir substrate. Therefore, coir substrate generally wasted after being used for one time was reuseable by supplying organic fertilizer.

• Membrane Journal
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• v.12 no.1
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• pp.21-27
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• 2002

The formation of soluble microbial products(SMP) and molecular weight distribution on loading rate were observed in batch-type culture medium, which phenol was fed as a substrate. The molecular weight destribution was obtained by using 30K, 100K dalton and $0.45{\mu}$ membrane filters. When the phenol concentrationas a substrate was 120, 230 and 440 mg/L , the specific substrate utilization rate(q) showed 0.639, 1.281 and 1.744 mgTOC/mgMLSS/day, respectively. The endogenous biomass decay rate constant($K_d$) at each substrate concentration was 0.00536, 0.0661 and 0.0749($day^1$), respectively. The $SMP_e$ product rate constant($k_{SMP}_ e$) showed 0.006, 0.0058 and 0.0057($day^1$), respectively. The initial influent substrate during the course of time degraded and produced $SMP_s$. The $SMP_s$ was converted to the $SMP_{nd}$ and endogenous phase converted to the $SMP_e$ ingredients. The molecula weight distribution on loading rate was converted to a higher MW during the course of time.

• Corrosion Science and Technology
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• v.23 no.3
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• pp.228-234
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• 2024

Zinc wiping is a phenomenon used to control zinc-coating thickness on steel substrate during hot dip galvanizing by equipment called air knife. Uniformity of zinc coating weight in length and width profile along with surface quality are most critical quality parameters of galvanized steel. Deviation from tolerance level of coating thickness causes issues like overcoating (excess consumption of costly zinc) or undercoating leading to rejections due to non-compliance of customer requirement. Main contributor of deviation from target coating weight is dynamic change in air knives equipment setup when thickness, width, and type of substrate changes. Additionally, cold coating measurement gauge measure coating weight after solidification but are installed down the line from air knife resulting in delayed feedback. This study presents a coating weight control model (Galvantage) predicting critical air knife parameters air pressure, knife distance from strip and line speed for coating control. A reverse engineering approach is adopted to design a predictive, prescriptive, and descriptive model recommending air knife setups that estimate air knife distance and expected coating weight in real time. Implementation of this model eliminates feedback lag experienced due to location of coating gauge and achieving setup without trial-error by operator.

• Journal of Ecology and Environment
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• v.44 no.1
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• pp.45-53
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• 2020

Background: The black soldier fly (Hermetia illucens) is gaining attention as an efficient decomposer of food waste. However, recalcitrant compounds such as plastics mixed into food waste may have negative effects on its growth and survival. Moreover, its efficiency of food waste degradation may also be affected by plastics. In addition, salt (NaCl) can also be present in high concentrations, which also reduces the efficiency of H. illucens-mediated food waste treatment. In this study, we assessed the growth of black soldier fly larvae (BSFL) reared on food waste containing polyethylene (PE) and polystyrene (PS) and NaCl. The weight of BSFL was measured every 2-4 days. Survival and substrate reduction rates and pupation ratio were determined at the end of the experiment. Results: The total larval weight of Hermetia illucens reared on food waste containing PS was greater than that of the control on days 20 and 24. However, the survival rate was lower in the group treated with 5% PS, as was substrate reduction in all PS-treated groups. The weight of BSFL reared on food waste containing PE was lower than that of the control on day 6. PE in food waste did not affect the survival rate, but the pupation ratio increased and substrate consumption decreased with increasing PE concentrations. Regardless of the plastic type, the addition of NaCl resulted in decreased larval weight and pupation ratio. Conclusions: Larval growth of black soldier fly was inhibited not by plastics but by substrate salinity. Additional safety assessments of larvae reared on food waste containing impurities are needed to enable wider application of BSFL in vermicomposting.

• Journal of Bio-Environment Control
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• v.33 no.2
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• pp.114-119
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• 2024

Rockwool substrate has superior physicochemical characteristics and is often used in crop cultivation. However, rockwool substrate has the disadvantages of high purchase cost and difficulty in disposal. Reuse of substrate can compensate for these disadvantages. Substrate must be disinfected and rehydrated during reuse, and various physicochemical changes during this process must also be considered. This study was to compare the physical properties of two types of rockwool substrates (reused and unused) and to evaluate the reuse potential of rockwool substrate by analyzing the chemical properties of the reused rockwool substrate during the rehydration process. The experiment on substrate physicochemical properties comparison was conducted from March to August 2023 using used rockwool substrates in tomato cultivation and unused rockwool substrates. Drainage time, drainage volume, and substrate weight were measured using load cells installed at the top and bottom of the irrigation monitoring system. The reused rockwool substrate weight and density were higher than those of the unused rockwool substrate, while the average drainage time after irrigation was 1.5 times longer for the reused rockwool than for the unused rockwool. The salinity concentration in different parts of the reused rockwool substrate was found to be lower in the reused rockwool substrate compared to the unused rockwool substrate. The electrical conductivity of the drainage was at its peak at the beginning of the drainage and decreased exponentially as the drainage volume increased. Change in electrical conductivity of the drainage over the irrigation time showed an exponential decay pattern. Through the experiments, the potential reusability of the rock wool substrate was assessed by conducting a comparative analysis of its physicochemical properties.