1,768 research outputs found

    New fitting formula for cosmic non-linear density distribution

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    We have measured the probability distribution function (PDF) of cosmic matter density field from a suite of N-body simulations. We propose the generalized normal distribution of version 2 (Nv2) as an alternative fitting formula to the well-known log-normal distribution. We find that Nv2 provides significantly better fit than the log-normal distribution for all smoothing radii (2, 5, 10, 25 [Mpc/h]) that we studied. The improvement is substantial in the underdense regions. The development of non- Gaissianities in the cosmic matter density field is captured by continuous evolution of the skewness and shifts parameters of the Nv2 distribution. We present the redshift evolution of these parameters for aforementioned smoothing radii and various background cosmology models. All the PDFs measured from large and high-resolution N-body simulations that we use in this study can be obtained from a Web site at https://astro.kias.re.kr/jhshin.Comment: Accepted for publication in Ap

    Key Strains, Anger and Delinquency: The General Strain Theory Test on Sourth Korean Youths From Low-Income Households

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    General Strain Theory: Negative relations of strains create unpleasant emotions (e.g., anger and depression), which lead strained people to commit crimes as their coping methods. Strains are more likely to lead to crimes

    Impacts of Gender Inequality and Poverty on Trafficking in Women

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    Women represent approximately 75% of human trafficking victims. This study reviews what is and is not known about human trafficking and what might be accomplished in future research

    Functionalization of Stable Metal-Organic Frameworks and Their Applications

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    Metal–organic frameworks (MOFs) are newly emerging inorganic–organic hybrid porous materials with diverse crystalline structures, high surface areas, and tunable pores. This dissertation primarily focuses on design and synthesis of MOFs as well as the development of synthetic methodologies to target stable MOFs with desired functionalities. In the second section, a linker exchange strategy was developed as a route to functionalize a mesoporous MOF, PCN-333, through thermodynamic control. This strategy allowed a facile incorporation of a variety of functional groups into the mesoporous MOF without compromising integrity of the parent MOF. In the third section, a dual-exchange method was studied using a sequential linker exchange and metal metathesis on PCN-333(Fe) to achieve a chemically robust mesoporous Cr-MOF with desired functional group. Dual exchange showed the potential of this method to be a general approach to highly stable Cr-MOFs with desired functional groups upon selection of appropriate MOF template. In the fourth section, a new Zn-MOF, SO-PCN, was designed and synthesized as a host of two dye linkers. SO-PCN showed energy transfer between the 2D porphyrinic photosensitizer layer and the photochromic switch pillar in the framework. Using photochromic reaction of the linker in SO-PCN, a reversible control of singlet oxygen generation was demonstrated. The catalytic activity of SO-PCN was also studied for photooxidation of 1,5-dihydroxynaphthalene. In the fifth section, a new synthetic strategy to incorporate multiple functional molecules within the MOF nanoparticles was demonstrated for control of 1^O2 generation for PDT. This strategy was developed to improve several inherent limitations from SOPCN in the previous section. First, a Zr-MOF nanoplatform showed much improved stability in aqueous media, compatible under physiological conditions. This strategy allows for tuning of the ratios between the photosensitizer and the switch molecule within the Zr-MOF nanoparticles, thus enabling maximization of the 1^O2 generation controllability. As a result, MOF nanoparticle formulation showed an enhanced PDT efficacy with superior 1^O2 control compared to that of homogeneous molecular analogues. In the sixth section, size-controlled synthesis of Zr-based porphyrinic MOF nanoparticles was studied through a bottom-up approach. The study provided mechanistic insights about the size control of the porphyrinic Zr-MOF nanoparticles. Size-dependent cellular uptake and ensuing PDT efficacy were also investigated to optimize the size of the MOF nanoparticles for PDT. Additionally, folic acid modification on the Zr6 node in the MOF showed further enhanced PDT efficacy via active targeting, demonstrating multifunctional MOF nanoplatform. In summary, methodologies to allow functionalization of highly stable MOFs have been designed and studied. Conceptual utilizations of MOF nanoparticles for biomedical applications have also been demonstrated with stable MOF nanoparticles, showing the advantages of the MOF formulation. The findings in this dissertation provide design principle and possible options for preparing targeted MOFs as required in desired applications

    천연 제올라이트가 혼합된 흡착성 성토재의 전단강도 특성 및 아연 흡착 특성 평가

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    학위논문 (석사)-- 서울대학교 대학원 : 건설환경공학부, 2017. 2. 박준범.In industrial complexes, gas stations and railbeds, soil and groundwater contamination have occurred frequently and at a high concentration. Especially, zinc, which is one of the most common contaminants in the industrial areas, is needed to be controlled properly. A concept of fill layer construction using adsorptive soil materials is introduced in this study to minimize spreading of contamination. The purpose of this study is to evaluate shear strength characteristics and adsorption capacity of candidate materials for adsorptive fill materials. The candidate materials consist of weathered granite soil as a base material and natural zeolite for adsorptive materials. The composition methods were amendment and partial substitution. Amendment was the composition method that zeolite similar to particle size distribution of weathered granite soils was amended to weathered granite soils. Partial substitution was the method that fine parts of weathered granite soils were substituted with fine particles of natural zeolite. Shear stength characteristics and adsorption capacities of zeolite-amended soils and partially substituted materials through compaction test, direct shear test and sorption isotherm equilibrium test. In case of amendment, test results showed that internal friction angle was decreased with increasing zeolite content while adsorption capacity was increased linearly. In case of partial substitution, shear strength parameters and adsorption capacities were higher than those of zeolite-amended soils. That is, partially substituted materials could be developed as adsorptive fill materials with maximizing adsorption capacity of materials and maintaining the shear strength of materials at weathered granite soils level.Chapter 1 Introduction 1 1.1 Background 1 1.2 Research Concept 4 1.3 Objective 5 Chapter 2 Literature Review 6 2.1 Previous Research 6 2.1.1 Zn Removal Efficiency of Zeolite 7 2.1.2 Zeolite-amended Materials 8 2.1.3 Researches on Development of Fill Materials 10 2.2 Data Analysis of Adsorption Isotherm Equilibrium Test 11 2.2.1 Langmuir Adsorption Isotherm Model 11 2.2.2 Freundlich Adsorption Isotherm Model 12 Chapter 3 Materials and Methods 14 3.1 Materials 14 3.2 Methods 15 3.2.1 Amendement 15 3.2.2 Adsorption Isotherm Equilibrium Tests in Different Particle Size of Zeolite Weathered Granite Soils 16 3.2.3 Partial Substitution 17 3.2.4 Tests of Evaluating Properties for Adsorptive Fill Materials 19 Chapter 4 Experimental Results and Discussion 20 4.1 Amendment 20 4.1.1 Compaction Test 20 4.1.2 Direct Shear Test 21 4.1.3 Adsorption Isotherm Equilibrium Test 23 4.1.4 Comparison with Different Zeolite Content 25 4.2 Adsorption Isotherm Equilibrium Tests in Different Particle Size of Zeolite Weathered Granite Soils 26 4.3 Partial Substitution 30 4.3.1 Compaction Test 30 4.3.2 Direct Shear Test 31 4.3.3 Adsorption Isotherm Equilibrium Test 33 Chapter 5 Conclusions 35 Bibliography 37Maste

    ADJUVANT RADIATION THERAPY AND OUTCOMES AMONG OLDER WOMEN WITH EARLY-STAGE ENDOMETRIAL CANCER

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    Background. National guidelines recommend that the benefits and risks associated with adjuvant radiation therapy (RT) for older cancer patients should be assessed carefully, evaluating the impact on life expectancy and quality of life. We used the Surveillance Epidemiology and End Results and the Medicare Health Outcomes Survey (SEER-MHOS) and the SEER-Medicare linkages to examine health-related quality of life (HRQOL) and mortality outcomes, as well as non-cancer factors associated with adjuvant RT for older women with early-stage EC Methods. In aim 1, we identified 1,140 women (aged≥65 years) diagnosed with first primary stage I-II EC who underwent hysterectomy and completed a survey ≥1-year post-diagnosis in the SEER-MHOS linkage (1998-2017). HRQOL T-scores were compared across treatment groups: hysterectomy alone, adjuvant external beam radiation therapy (EBRT), adjuvant vaginal brachytherapy (VBT), or adjuvant VBT+EBRT. In aim 2, we identified 25,654 women (aged ≥66 years) diagnosed with first primary stage I-II EC who underwent hysterectomy in the SEER-Medicare linkage (2004-2017). The prevalence of adjuvant RT associated with patient characteristics and health system factors were estimated. In aim 3, a subset of 19,880 women diagnosed with the disease during 2004-2016 were identified from the aim 2 cohort. All-cause- and EC-specific mortality risks were compared across the treatment groups.Results. Aim 1: Adjuvant VBT was associated with better general health on the HRQOL subscale measure (mean difference, 3.59; 95% CI, 0.56–6.62) vs hysterectomy alone. Aim 2: Adjuvant RT was less commonly administered to Asian Americans and Pacific Islanders than non-Hispanic Whites, residing in rural or high neighborhood-poverty counties. Adjuvant RT was more commonly administered to women treated by a gynecologic oncologist at larger academic hospitals. Aim 3: Adjuvant VBT was associated with reduced all-cause mortality (Hazard Ratio [HR], 0.84; 95% CI, 0.77–0.93) and EC-specific mortality (HR, 0.69; 95% CI, 0.54–0.88) vs hysterectomy alone. Conclusions. VBT may be considered as the possible adjuvant treatment of choice for older women with early-stage EC, given the favorable HRQOL and mortality outcomes. Our analyses also suggest that various non-cancer factors may affect the delivery of RT in real-world oncology practice.Doctor of Philosoph
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