• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.04a
• /
• pp.37-38
• /
• 2022

This study is attempted to propose an appropriate number of measurements by checking and statistically analyzing the change in hardness according to the number of measurements. As a result, there was no significant difference between the 20th and 30th data, and in the 10th case, the effect on errors occurring during measurement was found to be dominant. Therefore, as the number of measurements, proposing 20 times in consideration of the convenience of use. In addition, in order to minimize the effect on the measurement error, it is proposed to remeasure the surface mane of the measurement surface and the test value in which the error occurs on the average of the test values.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.6
• /
• pp.653-662
• /
• 1991

aThe terms of hard and soft as applied to wheats are descriptions of the texture of the kernel. A hard wheat kernel required greater force to cause it to disintegrate than those a soft wheat kernel. Factors than can affect the measurement of hardness outnumber those that affect hardness itself. Kernel texture is the most important single characteristic that affects the functionality of a common wheat. It affect the way in which must be tempered for milling ; the yield and the particle size, and density of flour particles ; and the end use properties in milling, breadmaking, production of soft wheat products, and noodle-making. Papers are reviewed from various sources not only hardness but flour functionality.

• Journal of the Korean institute of surface engineering
• /
• v.53 no.1
• /
• pp.36-42
• /
• 2020

In this study, two novel methods to measure the surface hardness of anodic oxide films on aluminum alloys are reported. The first method is to impregnate oil-based ink into pores in the anodic oxide film and then to clean the ink on the surface using ethanol, resulting in an impregnation of inks only inside of the pores in anodic oxide film. The second method is to coat the anodic oxide film surface with thin Au layer less than 0.1 ?. Both the ink-impregnating method and Au-coating method provided clear indentation marks on the anodic oxide film surface when it was indented using a pyramidal-diamond penetrator. Thus, Vickers hardness of anodic oxide films on aluminium alloy could be measured successfully and precisely from the anodic film surface. In addition, advantages and disadvantages of the ink-impregnating method and Au-coating method for the measurement of surface hardness of anodic oxide films are discussed.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.552-553
• /
• 2006

The present study investigates the behavior of the sintering and hardness of stainless steel samples reinforced with NbC and TaC. Matrixes of pure stainless steel were compacted with addition of up to 3% wt NbC or TaC in a cylindrical die of steel $(\phi\;=\;5,0\;mm)$ at 700 MPa and sintered in an electrical resistance furnace under argon atmosphere. The sintered samples were characterized by density and hardness measurement, optical microscopy and scanning electron microscopy (SEM). The preliminary results show that the size and distribution of carbides influence in the sintering and hardness of the sintered samples.

• Korean Journal of Materials Research
• /
• v.33 no.6
• /
• pp.242-250
• /
• 2023

Titanium, which has excellent strength and toughness characteristics, is increasingly used in the aerospace field. Among the titanium alloys used for body parts, more than 80 % are Ti-6Al-4V alloys with a tensile strength of 931 MPa. The spark plasma sintering (SPS) method is used for solidification molding of powder manufactured by the mechanical milling (MM) method, by sintering at low temperature for a short time. This sintering method avoids coarsening of the fine crystal grains or dispersed particles of the MM powder. To improve the mechanical properties of pure titanium without adding alloying elements, stearic acid was added to pure titanium powder as a process control agent (PCA), and MM treatment was performed. The properties of the MM powder and SPS material produced by solidifying the powder were investigated by hardness measurement, X-ray diffraction, density measurement and structure observation. The processing deformation of the pure titanium powder depends on the amount of stearic acid added and the MM treatment time. TiN was also generated in powder treated by MM 8 h with 0.50 g of added stearic acid, and the hardness of the powder was higher than that of Ti-6Al-4V alloy when treated with MM for 8 h. When the MM-treated powder was solidified in the SPS equipment, TiC was formed by the solid phase reaction. The SPS material prepared as a powder treated with MM 8 h by adding 0.50 g of stearic acid also formed TiN and exhibited the highest hardness of Hv1253.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.44 no.1
• /
• pp.78-85
• /
• 1999

To investigate kernel hardness, a compression test which is widely used to measure the hardness of individual kernels as a physical testing method was made simultaneously with the measurement of friabilin (15KDa) which is strongly associated with kernel hardness and was recently developed as a biochemical marker for evaluating kernel hardness in 79 Korean wheat varieties and experimental lines. With the scattered diagram based on the principal component analysis from the parameters of the compression test, 79 Korean wheat varieties were classified into three groups based on the principal component analysis. Since conventional methods required large amount of flour samples for analysis of friabilin due to the relatively small amount of friabilin in wheat kernels, those methods had limitations for quality prediction in wheat breeding programs. An extraction of friabilin from the starch of a single kernel through cesium chloride gradient centrifugation was successful in this experiment. Among 79 Korean wheat varieties and experimental lines 50 lines (63.3%) exhibited a friabilin band and 29 lines (36.7%) did not show a friabilin band. In this study, lines that contained high maximum force and the lower ratio of minimum force to maximum force showed the absence of the friabilin band. Identification of friabilin, which is the product of a major gene, could be applied in the screening procedures of kernel hardness. The single kernel analysis system for friabilin was found to be an easy, simple and effective screening method for early generation materials in a wheat breeding program for quality improvement.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.5
• /
• pp.571-578
• /
• 1997

The development of new approaches for wheat grain hardness assessment may impact the grain industry in marketing, milling and breeding. This experiment was to develop a new method for fast identification between softness and hardness, and for maintaining germinability of seed after measurement in wheat. Results from the comparisons of accuracy and significance between image analysis and conventional methods(NIRS and textrometer) were summarized. Data obatined from image analysis for grain hardness did not show any difference from those of the conventional methods. The protein content analyzed by micro-Kjeldahl method was significantly correlated with the grain hardness measured by image analysis, textrometer, and NIRS. The analysis for wheat grain hardness using image analysis may be used as an alternative method to the conventional methods. This method also takes the seeds after analysis can be utilized as breeding materials in early generations.

• Korean Journal of Veterinary Research
• /
• v.14 no.2
• /
• pp.185-189
• /
• 1974

Although considerable research has been done on the blood chemistry of domestic animals, little work has been made of the changes associated with age. Moreover, the records about physiology of the goat were not much available in Korea, and a comprehensive survey of the blood chemical values of the Korean native goat has not been made. The authors intended to biometric study on the hardness of bone of race horse and Jeju horse in Korea. The measurement of hardness of bone were performed in 272 race horses (Thoroughbred 91, Anglo-Arab 107, Arab 74) and in 109 Jeju horses by the caliper by Toryba's method. Some interesting facts obtained through this study were as follows: 1. There was not significant difference of bone hardness between male and female. The average of bone hardness by the Toryba's meteod were $23.07{\pm}1.01$ in race horse and $19.44{\pm}1.84$ in Jeju horse. 2. The grade of bone hardness of race horse were higher than those of Jeju horse(P<0.001). 3. The correlation coefficient between age and grade of bone hardness were r= +0.344 in Jeju horse, theme were statistically significant (P<0.01) and the regression equation was Y=0.29x+18.497.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.15 no.1
• /
• pp.2878-2878
• /
• 1973

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.15 no.1
• /
• pp.2879-2894
• /
• 1973