• Title/Summary/Keyword: Unit cell analysis

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Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications

  • Sivakumar, B.;Raj, S. Gokul;Kumar, G. Ramesh;Mohan, R.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3755-3760
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    • 2012
  • Single crystals of lithium potassium phthalate (LiKP) were successfully grown from aqueous solution by solvent evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction. The lithium potassium phthalate $C_{16}\;H_{12}\;K\;Li_3\;O_{11}$ belongs to triclinic system with the following unit-cell dimensions at 298(2) K;$a=7.405(5){\AA}$;$b=9.878(5){\AA}$;$c=13.396(5){\AA}$;${\alpha}=71.778(5)^{\circ}$;${\beta}=87.300(5)^{\circ}$;${\gamma}=85.405(5)^{\circ}$; having a space group P1. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurs in the compound. Thermal stability of the crystal was also studied by both simultaneous TGA/DTA analyses. The UV-Vis-NIR spectrum shows a good transparency in the whole of Visible and as well as in the near IR range. Third order nonlinear optical studies have also been studied by Z-scan technique. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results have been discussed in detail.

Finite element modeling of manufacturing irregularities of porous materials

  • Gonzalez, Fernando J. Quevedo;Nuno, Natalia
    • Biomaterials and Biomechanics in Bioengineering
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    • v.3 no.1
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    • pp.1-14
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    • 2016
  • Well-ordered porous materials are very promising in orthopedics since they allow tailoring the mechanical properties. Finite element (FE) analysis is commonly used to evaluate the mechanical behavior of well-ordered porous materials. However, FE results generally differ importantly from experimental data. In the present article, three types of manufacturing irregularities were characterized on an additive manufactured porous titanium sample having a simple cubic unit-cell: strut diameter variation, strut inclination and fractured struts. These were included in a beam FE model. Results were compared with experimental data in terms of the apparent elastic modulus (Eap) and apparent yield strength (SY,ap). The combination of manufacturing irregularities that yielded the closest results to experimental data was determined. The idealized FE model resulted in an Eap one order of magnitude larger than experimental data and a SY,ap almost twice the experimental values. The strut inclination and fractured struts showed the strongest effects on Eap and SY,ap, respectively. Combining the three manufacturing irregularities produced the closest results to experimental data. The model also performed well when applied to samples having different structural dimensions. We recommend including the three proposed manufacturing irregularities in the FE models to predict the mechanical behavior of such porous structures.

Effect of Strut Waviness on Structural Performance of Wire-Woven Bulk Kagome Cores (WBK 의 구조적 특성에 대한 와이어 굴곡 효과)

  • Lee, Ki-Won;Kang, Ki-Ju
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.9
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    • pp.1099-1103
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    • 2011
  • Since the mechanical strength and stiffness of wire-woven bulk Kagome (BK) have been theoretically estimated by assuming that WBK is composed of straight struts, the analytical solutions occasionally give substantial errors as compared with the experimental results. The struts of WBK are helically formed, which results in errors in the estimations In this study, for accurately predicting the mechanical properties of WBK, the effects of waviness and brazed part are taken into account for estimating the strength and stiffness of WBK. The results are compared with the measured experimental results and the results estimated by a finite element analysis performed on a unit cell under periodic boundary conditions (PBC).

Numerical comparison between lattice and honeycomb core by using detailed FEM modelling

  • Giuseppe, Pavano
    • Advances in aircraft and spacecraft science
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    • v.9 no.5
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    • pp.377-400
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    • 2022
  • The aim of this work is a numerical comparison (FEM) between lattice pyramidal-core panel and honeycomb core panel for different core thicknesses. By evaluating the mid-span deflection, the shear rigidity and the shear modulus for both core types and different core thicknesses, it is possible to define which core type has got the best mechanical behaviour for each thickness and the evolution of that behaviour as far as the thickness increases. Since a specific base geometry has been used for the lattice pyramidal core, the comparison gives us the opportunity to investigate the unit cell strut angle giving the higher mechanical properties. The presented work considers a detailed FEM modelling of a standard 3-point bending test (ASTM C393/C393M Standard Practice). Detailed FEM modelling addresses to detailed discretization of cores by means of beam elements for lattice core and shell elements for honeycomb core. Facings, instead, have been modelled by using shell elements for both sandwich panels. On lattice core structure, elements of core and facings are directly connected, to better simulate the additive manufacturing process. Otherwise, an MPC-based constraint between facings and core has been used for honeycomb core structure. Both sandwich panels are entirely built of Aluminium alloy. Prior to compare the two models, the FEM sandwich panel model with lattice pyramidal core needs to be validated with 3-point bending test experimental results, in order to ensure a good reliability of the FEM approach and of the comparison. Furthermore, the analytical validation has been performed according to Allen's theory. The FEM analysis is linear static with an increasing midspan load ranging from 50N up to 500N.

Anti-inflammatory and Neurotrophic 2H-1-Benzopyran Derivatives of Chaenomeles sinensis

  • Ha, Young Jun;Lee, Tae Hyun;Subedi, Lalita;Kim, Hye Ryeong;Moon, Gyuri;Kim, Sun Yeou;Kim, Chung Sub
    • Natural Product Sciences
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    • v.28 no.1
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    • pp.1-5
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    • 2022
  • Two 2H-1-benzopyran derivatives, methyl 8-hydroxy-2,2-dimethyl-2H-1-benzopyran-5-carboxylate (1) and methyl 8-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carboxylate (2), including a new compound (1) were isolated from the twigs of Chaenomeles sinensis. Their chemical structures were characterized based on analysis of NMR data including 1H and 13C, COSY, HSQC, and HMBC and HRMS data. The isolated compounds (1 and 2) were assessed for their anti-neuroinflammatory activity by measuring inhibition levels of nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells and for their neurotrophic activity by the secretion of nerve growth factor (NGF) in C6 cells. Compounds 1 and 2 exhibited powerful anti-neuroinflammatory effects with IC50 values of 17.14 and 19.30 μM, respectively, without cell toxicity, and also showed moderate effects on the stimulation of NGF secretion levels with 113.15 ± 3.54 and 130.20 ± 8.03%, respectively. The biosynthetic pathway of 1 and 2 was proposed that they would be derived from a protocatechuic acid and an isoprenyl unit.

A Study on Urethane Pad Blanking Process of Bellows Diaphragm for Hydrogen Compressor (수소압축기용 벨로우즈 다이아프램의 우레탄 금형 전단공정 연구)

  • Y. G. Kim;H. J. Park;K. E. Kim;M. P. Hong;G. P. Kang;K. Lee
    • Transactions of Materials Processing
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    • v.33 no.1
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    • pp.5-11
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    • 2024
  • The development of a next-generation hydrogen compressor, a key component in the expansion of hydrogen charging infrastructure, is in progress. In order to improve compression efficiency and durability, it is important to optimize the precision forming and shearing processes of the diaphragm, which is the bellows unit cell, as well as the optimization of diaphragm shape itself. In this study, we aim to show that die and process design technology that can synchronize the inner and outer shearing points of the diaphragm for the precision forming of product can be constructed based on a numerical simulation. First, the damage model that can predict the fracture points will be determined using the shear load and shear zone measurements obtained by performing a blanking test of AISI-633 stainless steel. Next, we will explain the overall procedure based on numerical analysis model how to determine the shearing points according to the deformation pattern of urethane die for various shearing die design.

The enhancing effect of Acanthopanax sessiliflorus fruit extract on the antibacterial activity of porcine alveolar 3D4/31 macrophages via nuclear factor kappa B1 and lipid metabolism regulation

  • Hwang, Eunmi;Kim, Gye Won;Song, Ki Duk;Lee, Hak-Kyo;Kim, Sung-Jo
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.11
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    • pp.1776-1788
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    • 2019
  • Objective: The demands for measures to improve disease resistance and productivity of livestock are increasing, as most countries prohibit the addition of antibiotics to feed. This study therefore aimed to uncover functional feed additives to help enhance livestock immunity and disease resistance, using Acanthopanax sessiliflorus fruit extract (ASF). Methods: ASF was extracted with 70% EtOH, and total polyphenolic and catechin contents were measured by the Folin-Ciocalteu and vanillin assay, respectively. The 3D4/31 porcine macrophage cells ($M{\Phi}$) were activated by phorbol 12-myristate 13-acetate (PMA), and cell survival and growth rate were measured with or without ASF treatment. Flow-cytometric analysis determined the lysosomal activity, reactive oxygen species levels (ROS), and cell cycle distribution. Nuclear factor kappa B ($NF-{\kappa}B$) and superoxide dismutase (SOD) protein expression levels were quantified by western blotting and densitometry analysis. Quantitative polymerase chain reaction was applied to measure the lipid metabolism-related genes expression level. Lastly, the antibacterial activity of 3D4/31 $M{\Phi}$ cells was evaluated by the colony forming unit assay. Results: ASF upregulated the cell viability and growth rate of 3D4/31 $M{\Phi}$, with or without PMA activation. Moreover, lysosomal activity and intracellular ROS levels were increased after ASF exposure. In addition, the antioxidant enzyme SOD2 expression levels were proportionately increased with ROS levels. Both ASF and PMA treatment resulted in upregulation of $NF-{\kappa}B$ protein, tumor necrosis factor $(TNF){\alpha}$ mRNA expression levels, lipid synthesis, and fatty acid oxidation metabolism. Interestingly, co-treatment of ASF with PMA resulted in recovery of $NF-{\kappa}B$, $TNF{\alpha}$, and lipid metabolism levels. Finally, ASF pretreatment enhanced the in vitro bactericidal activity of 3D4/31 $M{\Phi}$ against Escherichia coli. Conclusion: This study provides a novel insight into the regulation of $NF-{\kappa}B$ activity and lipid metabolism in $M{\Phi}$, and we anticipate that ASF has the potential to be effective as a feed additive to enhance livestock immunity.

Weekly Topotecan for Recurrent Small Cell Lung Cancer - a Retrospective Anatolian Medical Oncology Group Study

  • Altinbas, Mustafa;Kalender, Mehmet Emin;Oven, Basak;Sevinc, Alper;Karaca, Halit;Kaplan, M. Ali;Alici, Suleyman;Arpaci, Erkan;Yildiz, Ramazan;Uncu, Dogan;Camci, Celalettin;Gumus, Mahmut
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2909-2912
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    • 2012
  • Aim: To evaluate efficacy and tolerability of topotecan treatment for recurrent small cell lung carcinoma. Patients and Methods: A total of 62 patients were evaluated retrospectively. Statistical analysis was performed using GraphPad Instat (version 3.05). Results: DFifty five of patients (89%) were male and 7 (11%) were female. Median age was $56.7{\pm}9.3$ (34-75). Forty eight of patients (80%) were extensive stage (ES) at the time of diagnosis. Fifty of the patients (80.6 Medical Oncology Clinic) were given median 5.36 cycles of cisplatin-etoposide (2-8 cycles). Time to recurrence was $15.6{\pm}6.13$ weeks in patients with limited stage (LS) and $6.3{\pm}3.82$ weeks in extensive stage (ES) (p<0.0001). Overall survival was $14.0{\pm}6.08$ months in ES and $17.9{\pm}6.88$ months in LS. The difference between two groups was statistically meaningful (p=0.0447). The overall survival of the patients was $14.8{\pm}6.43$ months (4.5-40 months). In terms of survival, there was no difference between males and females (p=0.1171). In 17 (27%) patients who were refractory to topotecan or in whom progression occurred other chemotherapies were used. Conclusion: Small cell lung cancer is chemosensitive, but recurrences occur in short time. Other chemotherapy regimens are used in progression. Topotecan is one of them. Patients who were young and in whom recurrences occur late had given better response to topotecan. Because of the retrospective nature of the study, we couldn't reach the records exactly and consequently, rate and duration of response couldn't be calculated. In recurrent SCLC topotecan is one of the treatment choices. But both hematological and non hematological side effects should be taken into consideration.

Morphological studies on the dendritic cells in the mammary gland I. Appearance of the ATPase-positive dendritic cells (유선조직내에 출현하는 dendritic cell의 형태학적 연구 I. ATPase-positive dendritic cell의 분포양상)

  • Ryu, Si-yun;Lee, Cha-soo
    • Korean Journal of Veterinary Research
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    • v.28 no.2
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    • pp.227-239
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    • 1988
  • In order to investigate the morphological characteristics of dendritic cells in the mammary gland, the appearance on the clear cells(CLs) or ATPase-positive dendritic cells(APDCs) have been observed by the light microscope. The results obtained were summarized as follows: CLs were observed in the mammary tissues of the experimental animals, such as mice, rats, guinea pigs, rabbits, cats, dogs, pigs, cows and Korean native goats, and these CLs were confirmed as the ATPase-positive cells of typical dendritic appearance(APDCs), The APDCs were distributed in between the secretory epithelial cells, between the secretory epithelial cells and the myoepithelial cells, the basal area of the secretory epithelial cells, the interalveolar and interlobular connective tissues, and in between the epithelial cells of secretory duct. The APDCs were observed more frequently during the middle period of lactation than the other periods, and were irregularly or uniformly distributed according to the location. During the middle period of lactation, there were notable quantitative differences in the APDSs depending on the mammary glands of mice, rats, guinea pigs, rabbits and cats, The most prominent differences were recognized among the mice, guinea pigs and cats. The number of AP DCs per unit area was statistically fewer in the guinea pigs($209.07{\pm}51.75cells/mm^2$) than in the mice($221.00{\pm}50.94cells/mm^2$) and cats($223.56{\pm}49.68cells/mm^2$) (respectively, p<0.05, p<0.05). Among the A/J, DBA/2, C57BL/6 and NIH(GP) mice, the mean densities of APDCs was statistically significantly fewer in the DBA/2($196.65{\pm}43.47cells/mm^2$) than in the C57BL/6($248.40{\pm}41.40cells/mm^2$) and NIH(GP) ($235.98{\pm}55.89cells/mm^2$) (respectively, p<0.0000, p<0.0000), however no significant difference between the C57BL/6 and the NIH(GP) was recognized (p>0.1). Among the F344, SD and W rats, the statistical analysis were confirmed that there were significantly fewer APDCs in the F344($198.72{\pm}47.61cells/mm^2$) than in the SD($227.70{\pm}41.40cells/mm^2$) and W($223.56{\pm}49.68cells/mm^2$) (respectively, p<0.0000, p<0.0001), however no significant difference between the SD and the W was recognized(p>0.1). The mean difference between the inbred and the noninbred counts in the mice was statistically significant (p<0.0001), and the similar result was presented in the rats(p<0.0000).

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Prognostic Impact of Histology in Patients with Cervical Squamous Cell Carcinoma, Adenocarcinoma and Small Cell Neuroendocrine Carcinoma

  • Intaraphet, Suthida;Kasatpibal, Nongyao;Siriaunkgul, Sumalee;Sogaard, Mette;Patumanond, Jayanton;Khunamornpong, Surapan;Chandacham, Anchalee;Suprasert, Prapaporn
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5355-5360
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    • 2013
  • Background: Clarifying the prognostic impact of histological type is an essential issue that may influence the treatment and follow-up planning of newly diagnosed cervical cancer cases. This study aimed to evaluate the prognostic impact of histological type on survival and mortality in patients with cervical squamous cell carcinoma (SCC), adenocarcinoma (ADC) and small cell neuroendocrine carcinoma (SNEC). Materials and Methods: All patients with cervical cancer diagnosed and treated at Chiang Mai University Hospital between January 1995 and October 2011 were eligible. We included all patients with SNEC and a random weighted sample of patients with SCC and ADC. We used competing-risks regression analysis to evaluate the association between histological type and cancer-specific survival and mortality. Results: Of all 2,108 patients, 1,632 (77.4%) had SCC, 346 (16.4%) had ADC and 130 (6.2%) had SNEC. Overall, five-year cancer-specific survival was 60.0%, 54.7%, and 48.4% in patients with SCC, ADC and SNEC, respectively. After adjusting for other clinical and pathological factors, patients with SNEC and ADC had higher risk of cancer-related death compared with SCC patients (hazard ratio [HR] 2.6; 95% CI, 1.9-3.5 and HR 1.3; 95% CI, 1.1-1.5, respectively). Patients with SNEC were younger and had higher risk of cancer-related death in both early and advanced stages compared with SCC patients (HR 4.9; 95% CI, 2.7-9.1 and HR 2.5; 95% CI, 1.7-3.5, respectively). Those with advanced-stage ADC had a greater risk of cancer-related death (HR 1.4; 95% CI, 1.2-1.7) compared with those with advanced-stage SCC, while no significant difference was observed in patients with early stage lesions. Conclusion: Histological type is an important prognostic factor among patients with cervical cancer in Thailand. Though patients with SNEC were younger and more often had a diagnosis of early stage compared with ADC and SCC, SNEC was associated with poorest survival. ADC was associated with poorer survival compared with SCC in advanced stages, while no difference was observed at early stages. Further tailored treatment-strategies and follow-up planning among patients with different histological types should be considered.