더 연결되고, 시민적이며, 공감할 수 있는 세상을 위하여

마티유 르리에브르(Matthieu Lelièvre) 이응노미술관 2019 고암논총 Vol.8 No.-

Experimental and numerical investigation of non-reaction flow characteristics in a concentric staged dual-swirl combustor

Le Li,Pengfei Zhu,Qiandong Li,Jianqin Suo,Longxi Zheng 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4

In order to deeply understand the complex swirling flow characteristics of the typical staged and zoned combustor, particle image velocimetry measurement and large eddy simulation were used to study the steady and instantaneous flow field. The results show that an obviously central recirculation zone (CTRZ) cannot be formed by the single pilot stage swirler. When a main stage swirler with strong swirling flow is added, a large CTRZ appears in the concentric staged dual-swirl combustor. The CTRZ size in the co-rotating combustor is obviously larger than that in the counter-rotating combustor. The development process of the CTRZ is divided into three stages: P, P-M and M. The stages P and M are mainly dominated by the pilot stage and main stage swirling air, respectively. In addition, it can be seen from the instantaneous flow field that there is a single spiral precessing vortex core in the co-rotating and counter-rotating combustor.

The Deviation Terms in the Decomposition of Aggregate Productivity Growth

Le Li,Simona Settepanella 서울대학교 경제연구소 2022 Seoul journal of economics Vol.35 No.2

In the decomposition of aggregate productivity growth, corresponding components are generally indexed according to the deviation of individual-level productivity from aggregate productivity. This paper provides an alternative perspective and points out that this decomposition method seems more suitable for studying change in relative aggregate productivity growth than for aggregate productivity growth when a deviation term is adopted.

Thickness Effect on Thermal Stability by Phase Transition of Single Crystal Hematite Nanorings

Le Li,Fagen Li,XiaoPing Zhang,JUN WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.6

Single-crystal hematite (α-Fe2O3) nanorings with three different thicknesses were synthesized by a hydrothermal method. The results of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) show that the nanorings are single-crystal and have relatively uniform outer diameters of 160 nm, and heights of about 100 nm. Magnetic measurements up to 920K have been performed on hydrothermally synthesized α-Fe2O3 nanorings and nanoparticles using a quantum design vibrating sample magnetometer. A high temperature phase transition of thermal stability ( α-Fe2O3 to Fe3O4) occurs when magnetic measurement was performed under high vacuum ( < 9.5 x 10-5 Torr). The phase transition temperature is 670 K for nanorings with thickness of ~30 nm, 718 K for nanorings with thickness of ~50 nm, 678 K for nanorings with thickness of ~65 nm, and 640 K for ~35 nm nanoparticles. This data show better thermal stability of nanorings with the thickness of ~50 nm than the other two kinds of nanoring samples The Néel temperature (TN) of α-Fe2O3 nanorings with the thickness of ~50 nm is determined to be 937.2 K by magnetic measurement for the first time, about 22.8 K below the bulk value. The small reduction of the TN of the α-Fe2O3 nanorings is consistent with the finite-size scaling theory.

An Integrated Production and Distribution Planning Model in Shrimp Agroindustry Supply Chain

Lely Herlina,Machfud,Elisa Anggraeni,Sukardi 대한산업공학회 2022 Industrial Engineeering & Management Systems Vol.21 No.1

This study discusses the integration model of production and distribution planning in the shrimp agroindustry supply chain, consisting of four echelons: shrimp suppliers, shrimp agroindustry, logistics provider companies, and buyers. The shrimp agroindustry supply chain is an essential part of the supply chain of processed product food, which transforms raw shrimp into various processed shrimp frozen products. One form of collaboration between supply chain actors is the integration of production and distribution planning activities. A model is developed to determine the flow of goods from each echelon, the number of processed shrimp products in the agroindustry, and the supplies of processed shrimp products. The bi-objective mixed-integer linear programming is proposed to describe the characteristics of the problem to minimize the total supply chain costs and maximize service level. Non-dominated sorting genetic algorithm II (NSGA-II) is designed to solve the shrimp agroindustry supply chain problem. The sample problem from the shrimp agroindustry in East Java, Indonesia, is applied to exhibit an algorithm’s efficiency. The result shows the best solution for the total supply chain is 1.75 trillion, and the service level is 1,502,264.5.

Optimization Approach for Solvent Extraction Process of Oily Contaminated Soil with Addition of Biosurfactant

Lely Fitriyani,Edwan Kardena,Sukandar,Qomarudin Helmy 대한환경공학회 2021 대한환경공학회지 Vol.43 No.2

Objectives : Solvent extraction is a process in which not only enable to reduce oil contaminant from soil residue, but also capable to recover oil from soil matrix of oily contaminated soil which has opportunity to be reutilized. Optimization process has been simulated by previous studies related to type and dosage of solvents, variances of temperature, additional of surfactants, and other related parameters to increase oil removal from oily contaminated soil. This study seeks an approach of optimization for solvent extraction process to oily contaminated solid waste by conducting statistical analysis into laboratory experimentation from perspective of Total Petroleum Hydrocarbon (TPH) removal. Method : Biosurfactant became single extractors for multistage extraction process and also combined with other solvents which are acetone and toluene. Mixing method that utilized during the study was combination between horizontal shaking at 150 rpm in 15 min duration and centrifugation force at 1,570 g in 10 min duration. Statistical analysis were conducted to seek its multiple regression. Result : Study describing biosurfactant performance single extractor by using multistage extraction process achieve 77% TPH removal, while combination of biosurfactant and solvent extraction by using toluene and acetone also capable to increase TPH removal 7% higher from original performance of both toluene and acetone at solvent extraction. Conclusion : Surfactant and solvents combination is promising to improve TPH removal, while statistics analysis that implemented to observed extraction process has possibility to be used for engineering higher efficiency of extraction process.

The Governance of Mineral and Coal in Indonesia: The Theory U Approach

MINDARTI, Lely Indah,SUJONO, Sujono,ZAUHAR, Soesilo,HERMAWAN, Hermawan Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

The purpose of this study is to map mineral and coal (Minerba) policies by analyzing the law and producing research novelty on mineral and coal governance policies in Indonesia with the Theory U approach. This study uses a qualitative research with the U theory approach. The results of the SNA analysis indicate that good mineral and coal governance must be carried out at various levels, from micro to macro. First, related to regulations on mineral and coal governance at the macro level. Regulations regarding the management of mineral and coal need to be carried out with a deeper evaluation related to the tax system, licensing system, increased value added and downstreaming and mineral and coal funds. The second is related to the regulation of mining management in the meso level. Third, related to the management of mineral and coal at the micro level, it is necessary to conduct more stringent supervision of the impacts caused by the mining sector of the Minerba. In addition, surveillance is also carried out as per law in order to avoid harmful behavior for both the company and the state. The originality of this research is the theory of U in the Mining Law research.

The Fascinating Interplay between Growth Hormone, Insulin-Like Growth Factor-1, and Insulin

Aart J. van der Lely,Eline C. Nijenhuis-Noort,Kirsten A. Berk,Sebastian J. C. M. M. Neggers 대한내분비학회 2024 Endocrinology and metabolism Vol.39 No.1

This review intends to provide the reader with a practical overview of several (patho)physiological conditions in which knowledge of the interplay between growth hormone (GH), insulin-like growth factor-1 (IGF-1), and insulin is important. This might help treating physicians in making the right decisions on how to intervene and improve metabolism for the benefit of patients, and to understand why and how metabolism responds in their specific cases. We will specifically address the interplay between GH, IGF-1, and insulin in type 1 and 2 diabetes mellitus, liver cirrhosis, and acromegaly as examples in which this knowledge is truly necessary.

Iron-doped chitosan microsphere for As(III) adsorption in aqueous solution: Kinetic, isotherm and thermodynamic studies

Xiaoyu Lin,Leli Wang,Shi Jiang,Longzhe Cui,Gui-Ping Wu 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.7

Iron-doped chitosan microsphere was prepared successfully and employed for effective adsorption of As(III). The results showed that the adsorption capacity benefited from the increase of iron content, and the maximum adsorption capacity was achieved at pH=8. According to the study of adsorption kinetics, adsorption rate was controlled by liquid film diffusion at a lower rotational speed, while it was controlled by chemical reaction rate at a higher rotational speed. The Freundlich and Temkin models exhibited a better fit to adsorption isotherm data, which indicated the adsorption of As(III) on iron-doped chitosan microsphere was chemisorption and the active sites of adsorbents were non-uniform distributed. Adsorption process was a spontaneous exothermic reaction because its ΔG and ΔH were negative. In presence of cations (Cd2+, Pb2+ or Zn2+) in solution, the iron-doped chitosan microsphere also showed the significant removal of As(III). However, the existence of anions (NO3 , SO4 2 or PO4 3) inhibited the As(III) removal at different level. PO4 3 showed the most significant side effects on the removal of As(III) by iron-doped chitosan microsphere. The used iron-doped chitosan adsorbent can be effectively regenerated using 1.0mol·L1 NaOH solution, and the adsorption efficiency decreased only 15.69% after being reused three times. The results of XPS, FT-IR showed that the adsorption was mainly achieved by the coordination interaction between As (III) and doped Fe in adsorbent.

Good Agreement between an Interferon Gamma Release Assay and Tuberculin Skin Tests in Testing for Latent Tuberculosis Infection among HIV-Infected Patients in Indonesia

Reviono Reviono,Leli Saptawati,Dhani Redhono,Betty Suryawati 대한의학회 2019 Journal of Korean medical science Vol.34 No.40

Background: Latent tuberculosis infection is a condition where there is a persistent immune response to Mycobacterium tuberculosis without clinical manifestations of tuberculosis. Currently, there is no gold standard to diagnose latent tuberculosis infection. The tuberculin skin test and interferon-gamma release assay are currently used to diagnose latent tuberculosis infection. However, studies have shown inconsistencies regarding the level of agreement between these tests in different settings. In this study, we aimed to evaluate the agreement between these two tests for diagnosing latent tuberculosis infection in human immunodeficiency virus (HIV)-infected individuals. Methods: We screened HIV patients with no clinical symptoms of tuberculosis, a normal chest X-ray, and no history of tuberculosis or use of antituberculous drugs. Participants were tested with tuberculin skin test (TST) and T-SPOT.TB (an interferon gamma release assay) simultaneously. Participants' HIV stage was determined by measuring the level of CD4+ T-lymphocytes. Tuberculosis status was confirmed by sputum examination using GeneXpert. The level of agreement between the TST and T-SPOT.TB results was measured using Cohen's κ coefficient. Results: Of the 112 participants, 20 had a positive T-SPOT.TB test result, and 21 had a positive TST result. The TST and T-SPOT.TB test results showed a high level of agreement (κ = 0.648, P < 0.001). Performance of the tests did not vary with CD4+ level. However, in participants with CD4+ < 200 cells/mm3 , T-SPOT.TB detected more latent tuberculosis infections than the TST. Conclusion: There was good agreement between the TST and T-SPOT.TB results of latent tuberculosis infection in participants. TST is the preferred test for diagnosing latent tuberculosis infection in HIV-infected patients, especially in resource-limited settings, because it is simple and cost-effective. However, T-SPOT.TB may be useful to rule out latent tuberculosis infection in patients with severe immunodeficiency.