• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.664-667
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• 1995

The purpose of this paper is to consider the disk failure phenomenon based on the second kind Fredholm integral equation and numerical inversion of Laplace transform when the head hit disk asperities at HDI under antiplane impact loading. The model for analysis is a two layeered half-space with a circumferential surface edge crack. The optimum design parameters to reduce the disk failure due to impact are presented

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.615-620
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• 2010

In this study, five series of novel polyurethanes was synthesized by the polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate(2,6-TDI), 2,5-tolylene diisocyanate(2,5-TDI), 2,4-tolylene diisocyanate(2,4-TDI), and 1,4-phenylene diisocyanate(1,4-PDI), hexamethylene diisocyanate(HDI) with 4,4'-Bis(3-hydroxypropoxy)biphenyl (BP3), 4,4'-bis(3-hydroxypropoxy)biphenyl exhibited a smectic type mesophase. Monotropic mesophase was found for all synthesized liquid crystalline polyurethanes except HDI/BP3. In contrast, 1,4-PDI/BP3 without a methyl substituent in the phenylene unit exhibited no explicit mesomorphic behavior, which was confirmed by DSC and polarizing microscopy experiments. Structures of the compound were identified by FT-IR and $^1H$-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry(DSC), polarized optical microscopy(POM) and x-ray diffraction analysis.

• Polymer(Korea)
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• v.29 no.3
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• pp.253-259
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• 2005

Polyurethanes, synthesized by polyester polyols and aliphatic or aromatic diisocyanates for a crease resist finishing agent, were prepared by two-step reactions, that is, prepolymer synthesis and chain extension. The structures of synthesized polyurethanes were confirmed by the measurement of FT-IR and $^1H$-NMR spectrometer. The number average molecular weight ($\bar{M}_n$) and the weight average molecular weight ($\bar{M}_w$) of the polyurethane with aromatic diisocyanate (MDI) were higher than those of the synthesized polyurethanes with aliphatic diisocyanate (HDI, $H_{12}MDI$). The glass transition temperatures ($T_g$) of soft segments in polyurethanes with MDI, HDI, $H_{12}MDI$ were -25,-42 and -50$^{circ}C$, respectively. In the polyurethanes obtained by two-step reaction, thermal stability and tensile strength increased with increasing hard segment contents, whereas elongation at break decreased with increasing hard segment contents.

• Journal of the Korean Applied Science and Technology
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• v.23 no.4
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• pp.328-339
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• 2006

The PU flame-retardant coatings (TTBAH, ATBAH-10C, -20C, and -30C) were prepared using the synthesized ATBAs and HDI-trimer as curing agent at room temperature. The physical properties of PU flame-retardant coatings with chlorine and phosphorus were inferior to those with phosphorus only and the properties were getting worse with increasing chlorine content. Flame retardancy was tested with three methods. With the vertical method, complete combustion time of ATBAHs were $259^{\sim}347$ seconds, which means that the prepared coatings are good flame-retardant. With the $45^{\circ}$ Meckel burner method, char lengths of the three prepared coatings were less than 2.9 cm, which indicates that the prepared coatings are first grade. With the limiting oxygen index (LOI) method, the LOI values of the three prepared coatings were in the range of $30^{\sim}35%$, which proves good flame retardancy of the prepared coatings. from the result of flame retardancy tests of the specimens that contain the same amounts of flame retarding compounds. it was found that the coatings containing both phosphorus and chlorine show higher flame retardancy than the coatings containing only phosphorus. This indicates that there exists, some synergy effect between coexisting phosphorus and chlorine.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5669-5673
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• 2015

Background: Breast cancer is the most prevalent kind of cancer among women in Iran. Regarding the importance of cancer prevention and considerable variation of breast cancer incidence in different parts of the country, it is necessary to recognize regions with high incidence of breast cancer and evaluate the role of potential risk factors by use of advanced statistical models. The present study focussed on incidence of breast cancer in Iran at the province level and also explored the impact of some prominent covariates using Bayesian models. Materials and Methods: All patients diagnosed with breast cancer in Iran from 2005 to 2008 were included in the study. Smoking, fruit and vegetable intake, physical activity, obesity and the Human Development Index (HDI), measured at the province level, were considered as potential modulating factors. Gamma-Poisson, log normal and BYM models were used to estimate the relative risk of breast cancer in this ecological investigation with and without adjustment for the covariates. Results: The unadjusted BYM model had the best fit among applied models. Without adjustment, Isfahan, Yazd, and Tehran had the highest incidences and Sistan- Baluchestan and Chaharmahal-Bakhtiari had the lowest. With the adjusted model, Khorasan-Razavi, Lorestan and Hamedan had the highest and Ardebil and Kohgiluyeh-Boyerahmad the lowest incidences. A significantly direct association was found between breast cancer incidence and HDI. Conclusions: BYM model has better fit, because it contains parameters that allow including effects from neighbors. Since HDI is a significant variable, it is also recommended that HDI should be considered in future investigations. This study showed that Yazd, Isfahan and Tehran provinces feature the highest crude incidences of breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2041-2047
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• 2016

Background: Liver cancer (LC) is the sixth world most common cancer and the second leading cause of cancer death. Due to the importance and necessity of awareness about the incidence and mortality of diseases to perform prevention programs, this study focused on data for LC and its relationship with the human development index (HDI) and its components in Asia in 2012. Materials and Methods: This ecological study was based on GLOBOCAN data for Asian countries. We assessed correlations between standardized incidence rates (SIR) and standardized mortality rates (SMR) of LC with HDI and its components using of SPSS18. Results: A total of 582,420 incident cases and 557,097 deaths were recorded in Asian countries in 2012. The five with the highest SIR were Mongolia, Lao PDR, Vietnam, Republic of Korea and Thailand and those with the highest SMR were Mongolia, Lao PDR, Vietnam, Cambodia and Thailand. A negative relation was observed between HDI and LC for SIR of 0.049 (P=0.748) and for SMR of 0.07 (P=0.645), with life expectancy at birth a positive relation for SIR of 0.061 (P=0.687) and a negative relation for SMR of 0.079 (P=0.603), with the average years of education a negative relation fo SIR of 0.476 (p=0.952) and for SMR of 0.032 (P=0.832), and with the country income level per person a negative relation for SMI of 0.11 (p=0.465) and for SMR of 0.113 (P=0.455). Conclusions: The incidence of LC is more in less developed and developing countries but statistically significant correlations were not found between standardized incidence and mortality rates of LC, and HDI and its dimensions.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.104-111
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• 2013

Poymer blends of two degradable aliphatic polyesters, relatively expensive material polylactic acid (PLA) and relatively inexpensive material poly(butylene adipate-co-terephthalate) (PBAT), were used in this study. Three different kinds of modifiers were used with various amounts. Diisocyanate type methylenediphenyl 4,4'-diisocyanate (MDI) and hexamethylene diisocyanate (HDI) were used as modifiers and epoxy type coupling agents also used. The melt flow index (MFI) and dynamic viscoelasticity of various compositions of PLA/PBAT blends were studied. The mechanical property and morphology with respect to the fracture surface of PLA/PBAT blends were also investigated using tensile test and field emission scanning electronic microscopy, respectively. These tests were also used to verify the compatibility of PLA/PBAT and the effect of mechanical properties due to the use of modifiers. Tensile properties of PLA/PBAT blends modified with HDI were improved remarkably.

• STI Policy Review
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• v.8 no.1
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• pp.113-156
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• 2017

Although technological progress is considered a key element for economic growth and development of a country, strong empirical evidence in this regard is not available yet. Therefore, to establish the empirical link between technology progress and economic development, it is advisable to carry out a time series analysis. In this regard, the Technology Achievement Index (TAI) of 100 top economies has been developed to examine the position of countries' technological progress for the 21 years spanning 1995 to 2015. Countries have been ranked on their TAI which is based on four pillars; technology creation, diffusion of older innovations, diffusion of recent innovations, and development of human skills. As well, this current study re-calculates the Humane Development Index (HDI) of 100 top economies for the 21 years from 1995 to 2015. Ranking of countries' HDI values reflects three dimensions: A long lifespan (life expectancy index), knowledge (Education Index) and a decent standard of living (Gross National Income Index, or GNI). The Standard Deviation (SD) technique has been used to investigate the technological gap between individual countries and groups of countries or regions. For a more meaningful assessment, technological gaps from the maximum achievement value (i.e., one of the countries under study) are presented as well. To investigate the impact of technological progress on economic development, this study introduces a model in which the HDI is used as the dependent variable and the TAI and Gross Capital Formation (GCF) are used as independent variables. The HDI, TAI and GCF are used in this model as proxy variables for economic development, technological progress and capital respectively. Econometric techniques have been used to show the impact of technological progress on economic development. The results show that long-term associations exist between technology progress and economic development; the impact of technology progress on economic development is 13.2% while the impact is 4.3% higher in eight selected East South Asian countries, at 13.5%, than in eight selected highly developed countries (9.2%).

• Journal of the Korean Applied Science and Technology
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• v.20 no.3
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• pp.237-242
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• 2003

The high-solid coatings were prepared by blending the synthesized acrylic resin in the previous paper and hexamethylene diisocyanate-trimer and curing it at room temperature. The characterization of the films of the prepared coatings was performed. The impact resistance, $60^{\circ}C$ specular gloss, cross-hatch adhension, and heat resistance of the films proved to be good, and the pencil hardness and drying time proved to be slightly poor. Especially, there was a remarkable improvement in the heat resistance. This improvement may stem from the regular arrangement of ethyl groups introduced into the acrylic resin. From a viscoelastic measurement using a rigid-body pendulum, curing was accelerated with the $T_g$ value. With the increase in $T_g$, log damp value was lowered and dynamic viscoelasic $T_g$ of a cured film was increased.

• The Journal of Internal Korean Medicine
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• v.38 no.5
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• pp.834-841
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• 2017

Objectives: To report the clinical application and effects of ByeolGab (Trionycis Carapax) pharmacopuncture in patients with primary headache. Method: Three patients who suffered from primary headache were treated with ByeolGab pharmacopuncture and acupuncture for 2 weeks. We used the Henry Ford Headache Disability Inventory (HDI), a six point scale, and a visual analogue scale (VAS) three times and analyzed the results. Result: After treatment with ByeolGab pharmacopuncture, the VAS, HDI, and six point scale scores were improved in all three patients. The symptoms of headache and other symptoms were also improved. Conclusion: ByeolGab pharmacopuncture is an effective treatment for patients complaining of primary headache.