• KIEAE Journal
• /
• v.11 no.2
• /
• pp.91-96
• /
• 2011

The purpose of this study is to measure the environmental effects of different alternative building materials. The following building materials were tested: clay bricks, cement wall, and red-clay plaster. Four mock-up models were constructed using clay bricks, cement wall, red-clay plaster and the last model as the control model. The effects of the above four building materials on temperature, humidity, the emissions of formaldehyde, and V.O.C were measured. This experiment was conducted during September. The conclusions are as follows. Clay bricks were able to control temperature, humidity and filter formaldehyde by itself. The environment within the cement wall was not affected by the humidity changes outside. Red-clay plaster walls had little impact on the environment because it is very thin.!

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.24 no.1
• /
• pp.21-26
• /
• 2014

Red clay has been used for making rakuyaki for the past 400 years. Because the resources for red clay in Japan are being depleted, many potters in Japan began to develop new materials which can replace red clay. In this study, It is analyzed that the chemical and physical properties of red clay from Shigaraki (Shiga, Japan), and developed a novel engobe which can be used for making Rakuyaki instead of Shigaraki red clay. Results from Raman spectroscopic examination showed that ferric oxide content in Shigaraki red clay is 9.4 % (Goethite 5 %, Wustite 4.4 %), and that the mechanism of red color development by the firing at $900^{\circ}C$ for 10 min is the chemical transformation of Goethite into Hematite, and the subsequent formation of solid solution with Alumina and Silica. To make similar ferric oxide content to that of Shigaraki red clay, we added 5 g of Goethite and 9 g of Wustite to 100 g of White kaolin from Hadong area (Gyeongsangnam-do, Korea). The $L^*a^*b^*$ color scale of the mixture was 56.83, 27.22, and 23.28, respectively, and stable red color was successfully developed under the same firing condition used for Shigaraki red clay.

• Geomechanics and Engineering
• /
• v.30 no.5
• /
• pp.471-478
• /
• 2022

Creep of soils has a significant impact on mechanical properties. The one-dimensional consolidation creep test, thermal analysis test, scanning electron microscope (SEM) test, and mercury compression test were performed on Guilin red clay to study the changes in bound water and microstructure during the creep process of Guilin red clay. According to the results of the tests, only free and weakly bound water is discharged during the creep of Guilin red clay. When the consolidation pressure p is in the 12.5-400.0 kPa range, it is primarily the discharge of free water; when the consolidation pressure p is in the 800.0-1600.0 kPa range, the weakly bound water is converted to free water and discharged. After consolidation creep, the microstructure of soil changes from granular overhead contact structure to flat sheet-like stacking structure, with a decrease in the number of large and medium pores, an increase in the number of small and micro pores, and a decrease in the fractal dimension of pores. The creep process of red clay is the discharge of weakly bound water as well as the compression of large pores into small pores and the transition of soil particles from loose to dense.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.1
• /
• pp.130-138
• /
• 2016

The use of antibiotics in aquaculture raises environmental and food safety concerns because chronic exposure of an aquatic ecosystem to antibiotics can result in the spread of antibiotic resistance, bioaccumulation of antibiotics in the organisms, and transfer of antibiotics to humans. In an attempt to overcome these problems, high-concentration red clay was applied as an alternative antibiotic against the following common fish pathogens: Aeromonas salmonicida, Vibrio alginolyticus, and Streptococcus equinus. The growth of A. salmonicida and V. alginolyticus was retarded by red clay, whereas that of S. equinus was promoted. Phase contrast and scanning electron microscopy analyses confirmed the attachment of red clay on cell surfaces, resulting in rapid gravitational removal and cell surface damage in both A. salmonicida and V. alginolyticus, but not in S. equinus. Different cell wall properties of grampositive species may explain the unharmed cell surface of S. equinus. Significant levels of oxidative stress were generated in only the former two species, whereas significant changes in membrane permeability were found only in S. equinus, probably because of its physiological adaptation. The bacterial communities in water samples from Oncorhynchus mykiss aquacultures supplemented with red clay showed similar structure and diversity as those from oxytetracycline-treated water. Taken together, the antibiotic effects of high concentrations of red clay in aquaculture can be attributed to gravitational removal, cell surface damage, and oxidative stress production, and suggest that red clay may be used as an alternative for antibiotics in aquaculture.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.05a
• /
• pp.21-22
• /
• 2019

This study is designed to apply natural clay replaceable redmud as ceramic material by mixing redmud with the materials used in existing brickmaking in laboratory environment. Therefore, through this study, the redmud is recycled as a raw material for clay bricks and presented as a basic material for the use of redmud in clay bricks.

• Journal of Animal Science and Technology
• /
• v.44 no.1
• /
• pp.61-68
• /
• 2002

This study was conducted to estimate the effects of high quality cubed roughage and red clay (0%, 1%, 2%) on growth performance, meat quality and economical benefits. Thirty-six 6 month-old Korean native cattle, averaging 156kg of BW, were assigned to six groups in a 2 (rice straw : RT, rice straw+cubed roughage : RCT) ${\times}$ 3 (0, 1, 2% red clay). During experimental period, the high quality cubed roughage added into rice straw treatment (RCT) was superior to the only rice straw treatment (RT) on daily gain and feed efficiency and final weight 10%, 6.8%, 8.2% (P$<$0.05) respectively. But the addition of red clay did not affect and even 2% addition decreased those parameters. For meat quality and economical analysis, the addition of high quality cubed roughage made an outstanding result and for RT treatment, only 1% red clay indicated good effects while both 1% and 2% red clay were better than 0% for RCT treatment. From these results, it is assumed that the addition of red clay for fattening Korean native cattle has no effects on growth performance but 1% treatment has good results on improving meat quality and economical benefits. It also suggests that the combination high quality roughage and concentrated red clay is beneficial for producing high quality meat in with economical benefits.

• Geomechanics and Engineering
• /
• v.34 no.5
• /
• pp.473-480
• /
• 2023

Acid rain of soils has a significant impact on mechanical properties. An X-ray diffraction test, scanning electron microscope (SEM) test, laser particle size analysis test, and triaxial unconsolidated undrained (UU) test were carried out in red clay soils with different compaction degrees under the effect of different concentrations of acid. The experiments demonstrated that: the dissolution effect of acid rain on colluvium weakened with the increase in the compacting degree under the condition of certain pH values, i.e., the damage to the structure of red clay soil was relatively light, where the number of newly increased pores in the soil decreased and the agglomeration of soil particles increased; for the same compacting degree, the structural gap decreased, and the agglomeration increased with the increase in the pH value (acidity decreases) of the acid rain; the dissolution rate of Si, Al, Fe, and other elemental minerals and cement in red clay soil was found to be higher under the effect of acid rain, in turn destroying the original structure of the soil body and producing a large number of pores. This is macroscopically expressed as the decrease of the soil cohesion and internal friction angle, thereby reducing the shear strength of the soil body.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.11a
• /
• pp.145-146
• /
• 2019

In this study, we evaluated the early strength of red clay soil with the polymer aqueous solution at rammed earth construction. In order to satisfy the demolding strength of the formwork be due to the rammed of red clay soil, the polymer aqueous solution was added to evaluate the compressive strength at the early age according to the consolidation level. As a result, a high compressive strength was exhibited with the formulation to which the polymer aqueous solution was added.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.11a
• /
• pp.141-142
• /
• 2020

In this study, the performance evaluation was performed by adding a polymer aqueous solution as a new additive of the red clay binder for use in the rammed earth construction method. The evaluation items were compressive strength and microstructure analysis. As a result of the experiment, the performance of the red clay binder was improved by efficiently bonding the silica particles by the polymerized polymer.

• Journal of Marine Bioscience and Biotechnology
• /
• v.6 no.1
• /
• pp.17-25
• /
• 2014

Periodically, harmful algal blooms (HABs) have occurred, with impacts on various areas including public health, tourism, and aquatic ecosystems, especially aquacultured and caged fisheries. To prevent or manage invasions of HABs into fish farms on an emergency basis, many methods have been proposed. Frequently over the past 30 years in coastal countries, treatments of clay and clay mixed with polyaluminum chloride (PAC) and chitosan have been tested for HAB-removal effectiveness in both the laboratory and the field. In Korea, yellow loess clay (hwangto) has been dispersed using electrolytic clay dispensers, both to decrease the amount of yellow loess clay's usage in containers and enhance HAB-removal efficiency. However, this emergency method has limitations, among which is the requirement for more effective controlling agents for field applications. Thus, in this paper, we review technologies for clay-based red tides prevention and control and their limitations, and, further, introduce next-generation algicidal technologies for the emergency protection of fish farms.