• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.399-405
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• 1991

The interaction of 4 dietary crude protein (13, 16, 19 or 22%) and 4 metabolizable energy (2600, 2800, 3000 or 3100 kcal ME/kg) levels on egg quality performances of Starcross layers were assessed between 245 and 275 days of age. The egg weight increased significantly with the increasing dietary protein and energy levels. But egg shape index, albumen index, yolk index, yolk dry matter, yolk protein, yolk fat, albumen protein and shell tickness were similar at all dietary protein and/or energy levels. The egg specific gravity and albumen weight increased but the yolk, weight, Haugh unit and albumen drymatter decreased with the increase of dietary protein levels and showed irregular trend with energy levels. The albumen dry matter and egg shell weight, however, were not affected by energy and protein levels. Simultaneous increase of protein and energy increased specific gravity, albumen index and shell thickness at a greater rate than that increased by the increase of protein or energy alone.

• Geomechanics and Engineering
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• v.17 no.4
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• pp.393-403
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• 2019

The cycling impact test of red sandstone soil under different axial pressure and different impact loads are conducted to reveal the mechanical properties and energy consumption mechanism of red sandstone soil with static-dynamic coupling loading. The results show that: Under the action of different axial pressure and different impact loads, the peak stress of the specimen increases, and then tends to be stable with the times of impact. With the increase of impact times, the specific energy absorption value of the red sandstone soil specimen is increased first and then gentle development trend. When the impact loads are certain, the larger the axial pressure is, the smaller the peak value of energy absorption, which indicates that the energy utilization rate is not high under the condition of large axial pressure. Through the analysis of energy utilization, it is found that the smaller the impact load, the higher the energy utilization rate. The greater the axial pressure, the lower the energy utilization rate. when the axial pressure is large, the impact loads corresponding to the maximum values of reflectivity, transmissivity and absorptivity are the same. The relationship between reflectivity and transmissivity is negatively correlated.

• Current Photovoltaic Research
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• v.10 no.1
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• pp.6-15
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• 2022

Climate change is among the most important issues facing mankind in modern society. However, global PV energy expansion has been driven mainly by OECD countries. We investigate the determinants of PV energy growth by panel data of selected OECD countries from 1991 to 2018. We investigate four categories of driving factors: socioeconomic, technological, country specific, and policy factors. The test results support that PV capacity growth is significantly driven by technology development and multidimensional environment policy factors. Socioeconomic factors such as CO₂, GDP, and electricity price are statistically significant on the growth of PV energy, too. Whereas, country-specific solar potential factor is the least related. As most of the socioeconomic factors are exogenous, we need to focus more on PV technology development and policy measures.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.717-722
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• 2012

Fluoride can be easily found in semiconductor and display industry. However, there is a lack of research for its effects on the related wastewater treatment. The objective of this study is to evaluate the microbial inhibitory effect by fluoride injection. The research entailed the assessment of removal efficiency of $TCOD_{Cr}$ according to the fluoride concentration and also the Specific Oxygen Uptake Rate (SOUR) was measured. The laboratory scale reactor was prepared and operated with the fluoride concentrations of 0, 10, 50, 100, and 200 mg/L based on concentrations frequently occurring in the wastewater. The results from this study showed that, as the fluoride concentration increase, the Specific Substrate Utilization Rate (SSUR) tend to decrease as expected. Also, the increase in fluoride concentrations resulted in the decrease in SOUR. It is determined that fluoride injection affects the microbial activity. Especially, The addition of above 200 mg/L fluoride into reactor caused rapidly decreased SSUR and SOUR due to the inhibitory effects of fluoride.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2452-2457
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• 2024

To obtain site-specific values of the Derived Concentration Guideline Levels (DCGLs) for decommissioning of KRR-1&2, the soil density and distribution coefficient values for Cs-137, a major contaminant radionuclide, were determined. The soil density was evaluated according to the test method established by the Korean Agency for Technology and Standards of the Ministry of Trade, Industry, and Energy (KATS). The distribution coefficient was evaluated using a batch test. The validity of using the evaluated soil density and distribution coefficient as site-specific values was assessed through radiation dose assessment reflecting these values. Average soil density value obtained was 1.738 g/cm³, which was within the typical range of normal soil density, 1.0-1.8 g/cm³. The average distribution coefficient value was 7,754 mL/g. Applying the maximum, average, and minimum values of the evaluated soil density and distribution coefficient showed similar radiation dose results, thus suggesting that it is reasonable to use the average values of each parameter as site-specific values. Findings of this study can help determine DCGLs that reflect the characteristics of the research reactor site.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.79-86
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• 2002

In end milling process the undeformed chip thickness and the cutting force components vary periodically with phase change of the tool. In this study, up end milling process is transformed to the equivalent oblique cutting. The varying undeformed chip thickness and the cutting force components in end milling process are replaced with the equivalent average ones. Then it can be possible to analyze the chip-tool friction and shear process in the shear plane of the end milling process by the equivalent oblique cutting system. According to this analysis, when cutting Inconel 718, 61, 64 and 55% of the total energy is consumed in the shear process with the helix angle 30$^{\circ}$, 40$^{\circ}$ and 50$^{\circ}$ respectively, and the balance is consumed in the friction process. With the helix angle of 40$^{\circ}$ the specific cutting energy consumed is smaller than with the helix angle 30$^{\circ}$ and 50$^{\circ}$.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.70-76
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• 2012

For Analysis and evaluation of ALC carbonation, ALC with various specific gravity was fabricated and silicate and siloxane were used for spraying on ALC surface. Silicon oil of water repellent was added to ALC slurry. ALC carbonation related with specific gravity and carbonation degree was decreased with specific gravity. It was guessed that permeation of $CO_2$ gas reduced depend on compact structure of ALC. ALC which sprayed silicate and siloxane represented more excellent carbonation resistance than Ref. ALC. ALC added silicon oil represented most excellent carbonation resistance.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.108-114
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• 2002

Red pine(Pinus densiflora) square timbers with 14.0 cm and 16.5 cm of face size and 24 m long were dried in a vacuum-press kiln and in a radio-frequency/vacuum(RF/V) kiln to compare drying rate, moisture content(MC) distribution and specific energy. RF/V drying rate was higher than vacuum-press drying rate. The effect of size of cross section on the RF/V drying rates were more pronounced than those of vacuum-press drying. The longitudinal- and the transverse MC distribution of dried square timber showed convex profile for the vacuum-press drying and concave profile for the RF/V drying. Moisture gradient of width direction was similar to the thickness direction in vacuum-press dried square timber and was more slight than that of the thickness direction in the RF/V dried large square timber. The specific energy consumption curve increased as MC decreased. Specific energy(kWh/kg of water evaporated) of the vacuum-press process required more than that of the RF/V process.

• Journal of Powder Materials
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• v.17 no.5
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• pp.379-384
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• 2010

In the present work, bismuth nanopowders with various particle size distributions were synthesized by controlling argon (Ar) gas flow rate and chamber pressure of a gas condensation (GC) apparatus. From the analyses of transmission electron microscopy (TEM) images and nitrogen gas adsorption results, it was found that as Ar gas flow rate increased, the specific surface area of bismuth increased and the average particles size decreased. On the other hand, as the chamber pressure increased, the specific surface area of bismuth decreased and the average particles size increased. The optimum gas flow rate and chamber pressure for the maximized electrochemical active surface area were determined to be 8 L/min and 50 torr, respectively. The bismuth nanopowders synthesized at the above condition exhibit 13.47 $m^2g^{-1}$ of specific surface area and 45.6 nm of average particles diameter.

• Membrane and Water Treatment
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• v.12 no.2
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• pp.65-73
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• 2021

Sponge ball cleaning can generate an abrasion effect, which leads to an attractive increasing in both permeate flux and membrane rejection. The aim of this study was to investigate the influence of the daily sponge ball cleaning (SBC) on the performance of different UF cross-flow membrane modules integrated with a bioreactor. Two 1"-membrane modules and one 1/2"-membrane module were tested. The parameters measured and controlled are temperature, pH, viscosity, particle size, dissolved organic carbon (DOC), total suspended solids (TSS), and permeate flux. The permeate flux could be improved by 60%, for some modules, after 11 days of daily sponge ball cleaning at a transmembrane pressure of 350 kPa and a flow velocity of 4 m/s. Rejection values of all tested modules were improved by 10%. The highest permeate flux of 195 L/㎡.h was achieved using a 1"-membrane module with the aid of its negatively charged membrane material and the daily sponge ball cleaning. In addition, the enhancement in the permeate flux caused by daily sponge ball cleaning improved the energy specific demand for all tested modules. The negatively charged membrane showed the lowest energy specific demand of 1.31 kWh/㎥ in combination with the highest flux, which is a very competitive result.