• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.7-11
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• 1999

This experiment was conducted to investigate the effects of soil conditioners, such as lime, borax, poultry waste sawdust manure (P.W.S.M) and mixed oil cakes (M.O.C), on the rutin biosynthesis and the yield of buckwheat. The content of phosphorus ($P_2O_5$) in buckwheat plants before flowering was higher at before flowering than that of flowering time at all plots. The content of nitrogen (N), potassium ($K_2O$), calcium (CaO) and magnesium (MgO) was lower at before flowering than those of flowering time at all plots. The contents of rutin in buckwheat plant at flowering time was higher than that at before flowering content of rutin in leaf was higher than that in stem. The contents of rutin in buckwheat plant was the highest at the plot treated with borax (B) compared to other plots. Correlation between rutin and amino acid was positive in buckwheat leaf, while it was negative in buckwheat stem. The yield of buckwheat was 21 percent higher at the plot treated with borax than the plot applied with the other three ingredients.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.380-387
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• 2015

A lead slowing-down spectrometer (LSDS) system is a promising nondestructive assay technique that enables a quantitative measurement of the isotopic contents of major fissile isotopes in spent nuclear fuel and its pyroprocessing counterparts, such as $^{235}U$, $^{239}Pu$, $^{241}Pu$, and, potentially, minor actinides. The LSDS system currently under development at the Korea Atomic Energy Research Institute (Daejeon, Korea) is planned to utilize a high-flux ($>10^{12}n/cm^2{\cdot}s$) neutron source comprised of a high-energy (30 MeV)/high-current (~2 A) electron beam and a heavy metal target, which results in a very intense and complex radiation field for the facility, thus demanding structural shielding to guarantee the safety. Optimization of the structural shielding design was conducted using MCNPX for neutron dose rate evaluation of several representative hypothetical designs. In order to satisfy the construction cost and neutron attenuation capability of the facility, while simultaneously achieving the aimed dose rate limit (< $0.06{\mu}Sv/h$), a few shielding materials [high-density polyethylene (HDPE)eBorax, $B_4C$, and $Li_2CO_3$] were considered for the main neutron absorber layer, which is encapsulated within the double-sided concrete wall. The MCNP simulation indicated that HDPE-Borax is the most efficient among the aforementioned candidate materials, and the combined thickness of the shielding layers should exceed 100 cm to satisfy the dose limit on the outside surface of the shielding wall of the facility when limiting the thickness of the HDPE-Borax intermediate layer to below 5 cm. However, the shielding wall must include the instrumentation and installation holes for the LSDS system. The radiation leakage through the holes was substantially mitigated by adopting a zigzag-shape with concrete covers on both sides. The suggested optimized design of the shielding structure satisfies the dose rate limit and can be used for the construction of a facility in the near future.

• Journal of the Korea Institute of Building Construction
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• v.22 no.2
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• pp.125-136
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• 2022

This research is to reduce the formwork leakage of high-fluidity concrete caused by insufficient accuracy of formwork fabrication widely used for high-fluidity concrete to general strength concrete. However, in the actual construction site, because of the insufficient accuracy of formwork fabrication may cause leaking concrete of mortar through a gab of the formwork. Therefore, in this research, which builds on previous research into providing thixotropy with PVA and Borax, the use of thixotropy to reduce high-fluidity mortar leakage was evaluated. The results of the experiment proved that the use of thixotropy with PVA and Borax can contribute to reduction of the formwork leakage of high-fluidity mortar. This finding is expected to lead to further research on reducing leakage of high-fluidity concrete.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.605-609
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• 2001

Low density ceramic supporter was prepared by using fly ash as a starting material for the application to the biological aerated filter (BAF) system, and the effect of additives and sintering atmosphere on the apparent and bulk density of the carrier was examined. Borax, Na$_2$O and glass powders were added to produce liquid phase. The density of the supporter decreased as the amount of borax increased. The bulk density of 0.79 g/㎤ and the apparent density of 1.10 g/㎤ were obtained when the fly ash with 15% of borax was sintered at 116$0^{\circ}C$ for 15 minutes. The density also decreased as the plate glass powders past through 22${\mu}{\textrm}{m}$ size were mixed. When the fly ash with 12% of grass powder was sintered at 128$0^{\circ}C$ for 10 minutes, the bulk and apparent density were 0.90g/㎤ and 1.00 g/㎤, respectively. Apparent density of 1.6~1.8g/㎤ was obtained when the fly ash was sintered at 120$0^{\circ}C$ in a weak reducing atmosphere. By maintaining the reducing atmosphere and sintering at a high heating rate, the liquid phase was farmed from the reduced composition of fly ash. This resulted in the formation of closed pores that enabled the low apparent density.

• Journal of the Korean Wood Science and Technology
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• v.49 no.6
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• pp.602-615
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• 2021

Red jabon wood is a potential fast-growing species for veneer, furniture, and many other wood products, but its durability is very low. The purpose of this study was to investigate the effects of castor bean oil and heating on boron leaching, dimensional stability, and resistance to decay fungi in treated jabon wood. Red jabon wood was preserved with boron solutions containing 5% boron (boric acid, borax, or borax-boric acid). Following that, castor bean oil impregnation and heating were used as posttreatments. Furthermore, all the wood samples were tested in terms of leaching, dimensional stability, and resistance against Schizophyllum commune and Fomitopsis palustris fungi. This study discovered that boron compounds, castor bean oil, and heating treatments influenced the leaching, dimensional stability, and resistance of red jabon wood to decay fungi. The double impregnation of boric acid or borax and castor bean oil, followed by heating at 160℃, significantly reduced water absorption and leaching while increasing the dimensional stability and resistance of red jabon wood against the two tested decay fungi.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.141-147
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• 2017

The purpose of this study is to develop an inorganic filling adhesive using MKP and borax based on Dead-burn magnesia and fly ash. First, basic experiments was conducted to derive the proper addition rate of MKP. And this experiment was carried out according to addition ratio of borax. The test items are measured for pot life, flexural strength, compressive strength, adhesive strength, tensile strength, ratio of temperature change, ratio of hardening shrinkage, radon gas and formaldehyde emission. As a result, the proper addition rate of phosphate was 35%. The pot time is about 10minutes, 15minutes and 25minutes according to addition rate of borax. The flexural strength and compressive strength were obtained at 12hours for minimum flexural strength of 8.0MPa and minimum compressive strength of 31.0MPa. The tensile strength was the least 4.1MPa, and the ratio of hardening shrinkage was maximum 2.4% and ratio of heat change was maximum - 0.3%, which satisfied all of the quality standards of 'KS F 4923' (epoxy resin for repairing concrete structures). Both Radon gas and formaldehyde emission was not detected.

• Journal of the Korean Ceramic Society
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• v.35 no.5
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• pp.479-485
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• 1998

Raw mateials such as limestone quartzite bauxite and anhydrite were used in the production of mod-ified beloite cement. Two kinds of clinker were synthesized with relatively higher content of $C_2S$ than that of $C_4A_3{\={S}}$ Concerning $C_2S$ the main mineral component borax ($Na_2O\;2B_2O_3\;10H_2O$) was added to stimu-late hydraulic reactivity and this would be possible by stabilizing ${\alpha}'-C_2S$ at room temperature. We had in-tended to compare burning and hydraulic characteristics of clinkers with one another by varying the amount of borax addition and to study the appropriate amount of anhydrite addition needed in the strengthening of cement during hydration. It was concluded that the effective amount of borax addition ne-eded for stabilization of ${\alpha}'-C_2S$ was 5 wt% in 60wt% $C_2S$ inclusive clinker and adding anhydrite in the ra-tio of 1.3 of $SO_3/Al_3O_3$ was appropriate in the production of cement by this clinker. Only ettringite was seen to contribute to the strength without additives but C-S-H was found to form along with ettringite with the addition of borax in the initial stage of hydration.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.245-254
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• 2009

As a substitute for CCA, which is inhibited due to its environmental pollution and human harmfulness, and CuAz and ACQ with a high cost, okara-based wood preservatives were formulated with okara hydrolyzates using copper sulfate and/or borax as a metal salt. The efficacy of the preservatives and X-ray microanalysis of wood specimens treated with the preservatives were examined to confirm the potential of the okara-based wood preservatives. Most of the preservatives showed excellent decay resistance against brown-rot fungi, Postia placenta and Gloeophyllum trabeum. The efficacy was improved when the acid concentration and temperature used for the hydrolysis of okara increased. In addition, when borax was added into copper sulfate/okara hydrolyzates preservative formulations, any decay was not found in the specimens. From the microscopic observation of the specimens treated with okara-based wood preservatives, it seems that okara is contributed to the fixing of metal salts in wood blocks. Therefore, it is speculated that okara-based wood preservatives can effectively protect wood against fungal attack as CuAz, and that the preservatives are sufficient to use as an alternative wood preservative of CCA, ACQ and CuAz.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.337-348
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• 2023

The central objective of this study is to curtail the leakage of mortar or cement paste, often resultant of ill-constructed formwork, by implementing thixotropy in the formulation of high-fluidity, standard-strength concrete. When such concrete is utilized in smaller scale construction projects, instances of formwork gaps due to suboptimal construction precision may lead to significant leakage of mortar and paste, a problem not typically encountered with traditional slump-flow concrete. In this investigation, Polyvinyl Alcohol(PVA) and borax are incorporated into the concrete mixture to induce thixotropy. The experimental design includes varying methodologies for integrating PVA and borax, while assessing alterations in diverse concrete performances, including thixotropy and leakage reduction potential that simulates formwork gap conditions. Under the experimental conditions defined within this study, it was found that replacing, rather than merely adding PVA and borax, aids in averting water addition via suspensions. This approach yielded promising results in terms of concrete properties and proved efficacious in stemming leakage in concrete possessing sufficient thixotropy. Notably, when a 6% PVA suspension was substituted, a significant reduction in leakage was observed. Consequently, it is projected that construction quality can be ensured, even with lower precision formwork, by applying thixotropy to concrete through the use of PVA and borax.

• International Journal of Concrete Structures and Materials
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• v.8 no.1
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• pp.61-68
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• 2014

This paper reports the physical properties and hydration products of slag cement that was prepared by activating ground granulated blast furnace slag with commercial lime and plaster of Paris (POP) as activators. The consistency, setting times and soundness of various mixes of slag-lime-POP is reported. The hydration products and formation of bonds in the paste during setting were studied with the help of SEM, FTIR and XRD tests and the same are correlated to the hydration process. The setting times of the mixes are found to be lower than that of the value prescribed for ordinary Portland cement (OPC). Borax is used as a setting retarder and a borax content of 0.4 % by mass gives setting times that are normally prescribed for OPC. In the early stages of setting C-A-S-H gels are found in this cementing material instead of C-S-H gel, as generally observed in the OPC.