• Title/Summary/Keyword: HFS

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Numerical study on the thermal performance of passively cooled hybrid fins (수동적으로 냉각되는 하이브리드 휜들의 열성능에 대한 수치적 연구)

  • Jeon, Mun Soo;Kim, Kyoung Joon
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.8
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    • pp.816-821
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    • 2013
  • This paper reports numerical study results with respect to the thermal performance of various hybrid fins (HFs) and a pin fin (PF) passively cooled under natural convection state. Investigated HFs are a basic hybrid fin (BHF), a hollow hybrid fin (HHF), and a solid hybrid fin (SHF). CFD models for both HFs and the PF have been developed to explore their thermal performance under various heat dissipations. Thermal performances of fins have been analyzed by quantifying array-based heat transfer coefficients, $h_a$, and mass-based heat transfer coefficients, $h_m$, for each fin. Study results show that $h_a$ of the SHF is 23% greater than that of the PF. $h_m$ of the HHF is found to be even 140% greater than that of the PF, and the HHF is found to be 40% better than the BHF in terms of the mass-based performance, $h_{m{\cdot}}$.

Effects of mealworm (Tenebrio molitor) larvae hydrolysate on nutrient ileal digestibility in growing pigs compared to those of defatted mealworm larvae meal, fermented poultry by-product, and hydrolyzed fish soluble

  • Cho, Kyung Hoon;Kang, Sun Woo;Yoo, Jong Sang;Song, Dae Kil;Chung, Yi Hyung;Kwon, Gyoo Taik;Kim, Yoo Yong
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.3
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    • pp.490-500
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    • 2020
  • Objective: To investigate effect of mealworm (Tenebrio molitor) larvae hydrolysate on nutrient ileal digestibility compared to those of dried mealworm larvae meal, fermented poultry by-product, and hydrolyzed fish soluble in growing pigs. Methods: A total of 12 crossbred ([Landrace×Yorkshire]×Duroc) growing pigs with average body weight of 28.70±0.32 kg were surgically equipped with simple T-cannulas. A total of 12 pigs were assigned to individual metabolic crates and allotted to one of four treatments with 3 replicates in a fully randomized design. Results: Apparent ileal digestibility (AID) of dry matter (DM) was the highest in pigs fed HML diet. AIDs of crude protein (CP) were higher in pigs fed HML and DMLM diets than those in pigs fed the other two diets. AID of total amino acid was higher (p = 0.06) in pigs fed HML diet. AIDs of lysine (Lys), methionine (Met), and threonine (Thr) were similar in pigs fed DMLM and HML diets, but were higher (p = 0.05, p<0.05, and p = 0.05, respectively) than those in pigs fed FPBM or HFS diet. Pigs fed HML diet had higher standardized ileal digestibilities (SIDs) of DM and CP (p<0.05 and p<0.05, respectively) compared to pigs fed the other FPBM and HFS diets. SIDs of total amino acid were not different (p = 0.06) between treatments. For SIDs of Lys, Met, and Thr, pigs fed HML and DMLM diets showed higher SIDs (p = 0.05, p<0.05, and p<0.05, respectively) than pigs fed FPBM and HFS diets. SIDs of non-essential amino acids (aspartic acid, glycine, and alanine) were higher (p<0.05, p<0.05, and p<0.05, respectively) in pigs fed HML, FPBM, and DMLM diets than those in pigs fed the HFS diet. AID and SID of glutamic acid were higher in pigs fed HML and FPBM diets. Conclusion: In conclusion, dietary supplementation of mealworm larvae hydrolysate had higher digestibility in DM, CP, Lys, Met, and Thr compared to dietary supplementation with fermented poultry by-product and hydrolyzed fish soluble.

Effects of integrative simulation practice on nursing knowledge, critical thinking, problem-solving ability, and immersion in problem-based learning among nursing students (문제중심학습 통합 시뮬레이션교육이 간호대학생의 간호지식, 비판적 사고성향, 문제 해결 능력 및 수업 몰입도에 미치는 효과)

  • Song, Young A
    • Women's Health Nursing
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    • v.26 no.1
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    • pp.61-71
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    • 2020
  • Purpose: This study was conducted to investigate the effects of problem-based learning-integrative simulation practice (PBL-ISP) on nursing knowledge, critical thinking, problem-solving ability, and immersion among nursing students. Methods: The study used a nonequivalent control group post-test design. A PBL-ISP educational program was provided to the experimental group, and hands-on practice using a high-fidelity simulator (HFS) was administered to the control group. There were 42 subjects in the experimental group and 40 in the control group. Data were collected during the fall semester of 2019. Using SPSS for Windows version 23.0, data were analyzed in terms of frequency, percentage, mean, standard deviation, the chi-square test, t-test, and Pearson correlation coefficients. Results: Significant differences between the experimental and control groups were found in nursing knowledge (t=3.67, p<.001), critical thinking (t=3.40, p=.001), problem-solving ability (t=3.52, p=.001) and immersion (t=4.44, p<.001). Conclusion: PBL-ISP was more effective in improving nursing knowledge, critical thinking, problem-solving ability, and immersion than was hands-on practice using an HFS.

A Two-Stage Scheduling Approach on Hybrid Flow Shop with Dedicated Machine (전용기계가 있는 혼합흐름공정의 생산 일정 계획 수립을 위한 2단계 접근법)

  • Kim, Sang-Rae;Kang, Jun-Gyu
    • Journal of Korean Society for Quality Management
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    • v.47 no.4
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    • pp.823-835
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    • 2019
  • Purpose: This study deals with a production planning and scheduling problem to minimize the total weighted tardiness on hybrid flow shop with sets of non-identical parallel machines on stages, where parallel machines in the set are dedicated to perform specific subsets of jobs and sequence-dependent setup times are also considered. Methods: A two-stage approach, that applies MILP model in the 1st stage and dispatching rules in the 2nd stage, is proposed in this paper. The MILP model is used to assign jobs to a specific machine in order to equalize the workload of the machines at each stage, while new dispatching rules are proposed and applied to sequence jobs in the queue at each stage. Results: The proposed two-stage approach was implemented by using a commercial MILP solver and a commercial simulation software and a case study was developed based on the spark plug manufacturing process, which is an automotive component, and verified using the company's actual production history. The computational experiment shows that it can reduce the tardiness when used in conjunction with the dispatching rule. Conclusion: This proposed two-stage approach can be used for HFS systems with dedicated machines, which can be evaluated in terms of tardiness and makespan. The method is expected to be used for the aggregated production planning or shop floor-level production scheduling.

Effects of Aqueous Extracts of Cynanchum wilfordii in Rat Models for Postmenopausal Hot Flush

  • Lee, Gyuok;Choi, Chul-yung;Jun, Woojin
    • Preventive Nutrition and Food Science
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    • v.21 no.4
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    • pp.373-377
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    • 2016
  • Menopausal hot flushes (HFs), which manifest as a transient increase in skin temperature, occur most frequently in postmenopausal women, and sometimes negatively influence daily life. We investigated the effect of an aqueous extract of Cynanchum wilfordii (CWW) in a rat model of menopausal HFs, where tail skin temperature (TST) is increased after the rapid estrogen decline induced by ovariectomy. Ten-week-old female rats were ovariectomized and treated with CWW for 1 week. We measured TST and rectal temperatures (RT) and investigated serum estradiol. The TST in ovariectomized (OVX) rats was significantly elevated after ovariectomy compared with control rats, whereas the RT in OVX rats was not elevated. Administration of CWW (200 mg/kg/d for 7 days, p.o.) significantly improved the skin temperature increase in OVX rats. The lower level of serum estradiol in OVX rats was significantly increased by supplying E2, but it was not affected by CWW. The present study indicates a need for future research involving treatment with high concentrations of C. wilfordii and measurement over 24 h.

A Case of Hemifacial Spasm Caused by an Artery Passing Through the Facial Nerve

  • Oh, Chang Hyun;Shim, Yu Shik;Park, Hyeonseon;Kim, Eun-Young
    • Journal of Korean Neurosurgical Society
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    • v.57 no.3
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    • pp.221-224
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    • 2015
  • Hemifacial spasm (HFS) is a clinical syndrome characterized by unilateral facial nerve dysfunction. The usual cause involves vascular compression of the seventh cranial nerve, but compression by an artery passing through the facial nerve is very unusual. A 20-year-old man presented with left facial spasm that had persisted for 4 years. Compression of the left facial nerve root exit zone by the anterior inferior cerebellar artery (AICA) was revealed on magnetic resonance angiography. During microvascular decompression surgery, penetration of the distal portion of the facial nerve root exit zone by the AICA was observed. At the penetrating site, the artery was found to have compressed the facial nerve and to be immobilized. The penetrated seventh cranial nerve was longitudinally split about 2 mm. The compressing artery was moved away from the penetrating site and the decompression was secured by inserting Teflon at the operative site. Although the facial spasm disappeared in the immediate postoperative period, the patient continued to show moderate facial weakness. At postoperative 12 months, the facial weakness had improved to a mild degree. Prior to performing microvascular decompression of HFS, surgeons should be aware of a possibility for rare complex anatomy, such as compression by an artery passing through the facial nerve, which cannot be observed by modern imaging techniques.

Enhancement of Lipid Metabolism and Antioxidant Defense Status in Mice Fed with High Fat Diet Supplemented with Antheraea pernyi Silk Fibroin Powder

  • Um, In-Chul;Rico, Catherine W.;Kweon, Hae-Yong;Kang, Mi-Young
    • International Journal of Industrial Entomology and Biomaterials
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    • v.22 no.2
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    • pp.95-100
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    • 2011
  • The effect of diet supplementation of Antheraea pernyi (A. pernyi) silk fibroin on the lipid metabolism and antioxidant defense status in high fat-fed mice was investigated. The animals were given normal control diet (NC group), high fat diet (HF group), or high fat diet supplemented with A. pernyi silk fibroin powder (HFS group) for 7 weeks. After the experimental period, the HF group showed significant increase in body weight, plasma and hepatic total cholesterol levels, and hepatic triglyceride concentration, and decreased activities of hepatic antioxidant enzymes relative to NC group. However, the HFS group exhibited marked reduction in body weight, plasma cholesterol and hepatic triglyceride levels, hepatic lipogenic enzyme activities, and lipid peroxidation rate, and higher high-density lipoprotein (HDL)-cholesterol level, fecal triglyceride content, and antioxidant enzymes activities compared with that of HF group. These findings demonstrate that dietary feeding of A. pernyi silk fibroin could improve the lipid metabolism and antioxidant defense system via regulation of hepatic antioxidant and lipogenic enzymes activities. Hence, this silk fibroin may be beneficial as a functional biomaterial for the development of therapeutic agent against high fat diet-induced hyperlipidemia and its related diseases.

An Interpretable Bearing Fault Diagnosis Model Based on Hierarchical Belief Rule Base

  • Boying Zhao;Yuanyuan Qu;Mengliang Mu;Bing Xu;Wei He
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.5
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    • pp.1186-1207
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    • 2024
  • Bearings are one of the main components of mechanical equipment and one of the primary components prone to faults. Therefore, conducting fault diagnosis on bearings is a key issue in mechanical equipment research. Belief rule base (BRB) is essentially an expert system that effectively integrates qualitative and quantitative information, demonstrating excellent performance in fault diagnosis. However, class imbalance often occurs in the diagnosis task, which poses challenges to the diagnosis. Models with interpretability can enhance decision-makers' trust in the output results. However, the randomness in the optimization process can undermine interpretability, thereby reducing the level of trustworthiness in the results. Therefore, a hierarchical BRB model based on extreme gradient boosting (XGBoost) feature selection with interpretability (HFS-IBRB) is proposed in this paper. Utilizing a main BRB alongside multiple sub-BRBs allows for the conversion of a multi-classification challenge into several distinct binary classification tasks, thereby leading to enhanced accuracy. By incorporating interpretability constraints into the model, interpretability is effectively ensured. Finally, the case study of the actual dataset of bearing fault diagnosis demonstrates the ability of the HFS-IBRB model to perform accurate and interpretable diagnosis.

Induction of cardiomyocyte-like cells from hair follicle cells in mice

  • Yong-Hee Kim;Bang-Jin Kim;Seok-Man Kim;Sun-Uk Kim;Buom-Yong Ryu
    • International Journal of Molecular Medicine
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    • v.43 no.5
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    • pp.2230-2240
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    • 2019
  • Hair follicles (HFs) are a well-characterized niche for adult stem cells (SCs), and include epithelial and melanocytic SCs. HF cells are an accessible source of multipotent adult SCs for the generation of the interfollicular epidermis, HF structures and sebaceous glands in addition to the reconstitution of novel HFs in vivo. In the present study, it was demonstrated that HF cells are able to be induced to differentiate into cardiomyocyte-like cells in vitro under specific conditions. It was determined that HF cells cultured on OP9 feeder cells in KnockOut-Dulbecco's modified Eagle's medium/B27 in the presence of vascular endothelial growth factors differentiated into cardiomyocyte-like cells that express markers specific to cardiac lineage, but do not express non-cardiac lineage markers including neural stem/progenitor cell, HF bulge cells or undifferentiated spermatogonia markers. These cardiomyocyte-like cells exhibited a spindle- and filament-shaped morphology similar to that presented by cardiac muscles and exhibited spontaneous beating that persisted for over 3 months. These results demonstrate that SC reprogramming and differentiation may be induced without resulting in any genetic modification, which is important for the clinical applications of SCs including tissue and organ regeneration.

Hand-Foot syndrome induced by sorafenib, a multitargeted tyrosine kinase inhibitor, in a patient with advanced renal cell carcinoma (진행된 신세포암 환아에게 sorafenib 투여시 발생한 Hand-Foot syndrome 1예)

  • Lee, Seung Hyun;Noh, Sung Hun;Kim, Sun Young;Jang, Kyu Yun;Hwang, Pyoung Han
    • Clinical and Experimental Pediatrics
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    • v.52 no.1
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    • pp.119-123
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    • 2009
  • Renal cell carcinoma (RCC) arising from epithelial cells of the renal tubules is a highly aggressive and malignant tumor in all ages; however, it rarely occurs in children. the standard treatment for RCC is radical nephrectomy with lymph node dissection when the tumor is localized and can be completely resected. Adjuvant chemotherapy, radiotherapy, and immunotherapy are used for pediatric patients with advanced RCC involving lymph nodes or metastatic lesions. Sorafenib is an oral, multikinase inhibitor that has recently been approved for use in metastatic RCC. Common toxicities that have been reported include dermatologic changes such as rash or desquamation and hand-foot skin reaction, diarrhea, fatigue, alopecia, and hypertension. In particular, hand-foot syndrome (HFS) an erythematous skin lesion of the palms and solesis most often caused by cytostatic chemotherapeutic agents. In this report, we have studied a 14-year-old female patient with hand-foot syndrome that occurred in association with sorafenib for the treatment of metastatic RCC. Furthermore, this case demonstrates that reversal of complications can be achieved by discontinuing the drug and intervention with topical steroids, vitamin E, and high-dose pyridoxine.