• Title/Summary/Keyword: damage condition

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Comparison of Vibration Characteristics of Cargo Bikes on General Roads and Bicycle Roads (일반도로와 자전거도로에서의 카고바이크 화물 적재함 진동 특성 비교)

  • Dong Yul Kim;Myenog Guk Yu;Heng Suk Lee;Sang Min Kim
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.29 no.3
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    • pp.175-179
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    • 2023
  • This paper analyzes the vibration characteristics within the cargo compartment of a three-wheeled cargo bike when used on both regular roads and dedicated bicycle lanes. When cargo is loaded into the cargo compartment of a cargo bike and driven on the road, the shocks and vibrations transmitted from the ground can potentially affect the transported goods and even lead to product damage. As the vibration characteristics applied to the cargo compartment may vary depending on the condition of the road, vibration sensors were attached to the cargo bike's cargo compartment for data collection during operation on different road types. According to KS T ISO 13355 standards, the cargo bike can withstand vibrations within the range of 10 Hz to 60 Hz when operating on both bicycle lanes and regular roads. However, it is observed that there are peaks exceeding the profile in the frequency range of 3-6 Hz. In the 70-200 Hz range, the profile is exceeded on both regular roads and bicycle lanes, with a tendency for higher exceedance on bicycle lanes. The Grms value within the frequency range of KS T ISO 13355 is 5.926 m/s2 (0.604 Grms). When operating on bicycle lanes with cargo, the Peak envelope optimization PSD value is 6.553 Grms, while on bicycle lanes, it is 7.708 Grms, indicating a difference of at least tenfold.

The ameliorating role of sofosbuvir and daclatasvir on thioacetamide-induced kidney injury in adult albino rats

  • Ahmed H. Moustafa;Heba F. Pasha;Manar A. Abas;Adel M. Aboregela
    • Anatomy and Cell Biology
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    • v.56 no.1
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    • pp.109-121
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    • 2023
  • Thioacetamide (TAA) exposure and hepatitis C virus infection are usually associated with renal dysfunction. Sofosbuvir (SFV) and daclatasvir (DAC) drugs combination has great value in the treatment of hepatitis C. The study aimed to identify the nephrotoxic effects of TAA and to evaluate the ameliorative role of SFV and DAC in this condition. Forty-eight adult male albino rats were divided into eight groups and received saline (control), SFV, DAC, SFV+DAC, TAA, TAA+SFV, TAA+DAC and TAA+SFV+DAC for eight weeks. Kidney and blood samples were retrieved and processed for histological (Hematoxylin and Eosin and Masson's trichrome), immunohistochemical (α-smooth muscle actin), and biochemical analysis (urea, creatinine, total protein, albumin, malondialdehyde, reduced glutathione, superoxide dismutase, and tumor necrosis factor-α). Examination revealed marked destruction of renal tubules on exposure to TAA with either hypertrophy or atrophy of glomeruli, increase in collagen deposition, and wide expression of α-smooth muscle actin. Also, significant disturbance in kidney functions, oxidative stress markers, and tumor necrosis factor-α. Supplementation with either SFV or DAC produced mild improvement in the tissue and laboratory markers. Moreover, the combination of both drugs greatly refined the pathology induced by TAA at the cellular and laboratory levels. However, there are still significant differences when compared to the control. In conclusion, SFV and DAC combination partially but greatly ameliorated the renal damage induced by TAA which might be enhanced with further supplementations to give new hope for those with nephropathy associated with hepatitis.

Nondestructive detection of crack density in ultra-high performance concrete using multiple ultrasound measurements: Evidence of microstructural change

  • Seungo Baek;Bada Lee;Jeong Hoon Rhee;Yejin Kim;Hyoeun Kim;Seung Kwan Hong;Goangseup Zi;Gun Kim;Tae Sup Yun
    • Computers and Concrete
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    • v.33 no.4
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    • pp.399-407
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    • 2024
  • This study nondestructively examined the evolution of crack density in ultra-high performance concrete (UHPC) upon cyclic loading. Uniaxial compression was repeatedly applied to the cylindrical specimens at levels corresponding to 32% and 53% of the maximum load-bearing capacity, each at a steady strain rate. At each stage, both P-wave and S-wave velocities were measured in the absence of the applied load. In particular, the continuous monitoring of P-wave velocity from the first loading prior to the second loading allowed real-time observation of the strengthening effect during loading and the recovery effect afterwards. Increasing the number of cycles resulted in the reduction of both elastic wave velocities and Young's modulus, along with a slight rise in Poisson's ratio in both tested cases. The computed crack density showed a monotonically increasing trend with repeated loading, more significant at 53% than at 32% loading. Furthermore, the spatial distribution of the crack density along the height was achieved, validating the directional dependency of microcracking development. This study demonstrated the capability of the crack density to capture the evolution of microcracks in UHPC under cyclic loading condition, as an early-stage damage indicator.

Imaging of Umbilical Venous Catheter-Related Hepatic Complications in Neonates (신생아의 제대 정맥 카테터와 관련된 간 합병증의 영상 소견)

  • Min Ju Kim;So-Young Yoo;Tae Yeon Jeon;Ji Hye Kim;Yu Jin Kim
    • Journal of the Korean Society of Radiology
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    • v.84 no.3
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    • pp.586-595
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    • 2023
  • An umbilical venous catheter (UVC) is commonly placed for central venous access in preterm or critically ill full-term neonates to provide total parenteral nutrition (TPN) and medication. However, UVCs can result in complications, including infection, portal vein thrombosis, and hepatic tissue injury. The inadvertent administration of hypertonic fluid through a malpositioned UVC can also cause hepatic parenchymal damage with mass-like fluid collection that simulates a tumorous condition during imaging. Ultrasonography and radiographic examinations play an essential role in detecting UVC-related complications. This pictorial essay aims to present the imaging findings of UVC-related hepatic complications in neonates.

The Non-destructive Inspection Using Infrared Thermal Technique on Reinforced Slopes by Shotcrete (적외선 열화상을 이용한 숏크리트 보강사면의 비파괴점검)

  • Shin, Chang-Gun;Lee, Song;Ahn, Sang-Ro
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.1
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    • pp.95-102
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    • 2007
  • It needs to Prevent damage as aging shotcrete itself exists as a dangerous component to comuting vehicles or infrastructure due to scaling, spaling, and loosening. However, it is hard to make an approach owing to a steep slope and high work, and there has been indicated a limit that it is difficult to grasp the internal condition of shotcrete on the surface. This study aimed to research internal defects that cannot be observed from the surface, by measuring a subtle thermal transfer on the shotcrete surface by using infrared thermography for overcoming such a technical limit. As a result of conducting an inspection through an analysis on measured data and fieldwork using an endoscope camera, it was impossible to accurately determine the wet part because of an excessive coating of shotcrete, yet, This study is proposed effictively extract a void part of the inside with non-destructive and non-touching method.

The Evaluation of Surface Scaling and Resistance of Concrete to Frost Deterioration with Freezing-Thawing Action by Salt Water (염화물이 함유된 동결수의 동결융해 작용에 따른 콘크리트의 내동해성과 표면열화 평가)

  • Kim, Gyu-Yong;Kim, Moo-Han;Cho, Bong-Suk;Lee, Seung-Hoon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.6
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    • pp.143-151
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    • 2007
  • This study presents the experimental results of frost durability including resistance to freezing-thawing and surface scaling of concrete. Mixing design was proportioned with the various water-binder ratio between 0.37 and 0.47 and three different binder compositions corresponding to Type I cement without any supplementary cementitious materials(OPC), Type II cement with 50% blast-furnace slag replacement(BFS50), and ternary cement with Type III cement, 15% fly ash, and 35% slag replacement (BFS35%+FA15%). Test results showed that the mixing design with BFS50% and BFS35%+FA15% exhibited higher durability factor than that made with OPC only. Finally, the use of blend cement containing slag can be used effectively in terms of frost durability of the concrete exposed to severe condition under coastal environment like as flying salt, sea water spray, etc.

Neglected Superior Ophthalmic Vein Enlargement before Delayed Symptom of Carotid-Cavernous Fistula in a Blowout Fracture: A Case Report and Literature Review

  • Sunkyu Park;Inhoe Ku;Ji-Ung Park
    • Archives of Plastic Surgery
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    • v.51 no.4
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    • pp.397-401
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    • 2024
  • Carotid-cavernous fistula (CCF) is a rare condition. However, it should be suspected when there are traumatic facial fractures, because if not diagnosed, it can lead to permanent damage such as blindness. Traumatic CCF often presents delayed symptoms, and delayed diagnosis without prompt treatment can lead to permanent injuries in optic and cranial nerves III, IV, V, and VI as well as intracranial hemorrhage. The routine initial modality for patients with suspected facial bone fractures is noncontrast computed tomography (CT) to identify any fracture lines and check for intracranial hemorrhage. We report a post-traumatic CCF case with a 4-day symptom delay, where left superior ophthalmic vein (SOV) enlargement was observed on the routine noncontrast facial CT with ipsilateral orbital wall fracture. When the patient first presented to the emergency room (ER), we did not detect vein enlargement on CT. Afterwards, the patient developed delayed symptoms of CCF and was readmitted to the ER. When we reanalyzed the first CT scan, an enlarged SOV was confirmed. The diagnosis was confirmed via magnetic resonance imaging angiography, and the patient was successfully treated with embolization of the fistula. Thus, we recommend reviewing ophthalmic vein enlargement that is readily identifiable through noncontrast CT for patients injured by craniofacial trauma to suspect the presence of delayed CCF at their initial presentation.

Evaluation of liver function using Cordyceps militaris extract powder in Sprague-Dawley rat with acute hepatic injury induced by dimethylnitrosamine

  • Heejin Park;Ju-Hye Kim;Mun-Hyoung Bae;Youngha Seo;Eun-Young Gu;Taek-Keun Oh;Byoung-Seok Lee
    • Korean Journal of Agricultural Science
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    • v.51 no.2
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    • pp.147-158
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    • 2024
  • Hepatic fibrosis refers to the scarring of liver tissue, often resulting from chronic liver injury or inflammation. It is characterized by excessive deposition of extracellular matrix proteins, impairing liver function and potentially progressing to cirrhosis if left untreated. To improve the liver functions, Cordyceps militaris, a species of parasitic fungus known for its medicinal properties, is used in the form of extract. It has been traditionally used in Chinese medicine to boost energy, improve stamina, and support overall health. In this study, we investigated the hepatoprotective effects of Cordyceps militaris extract powder in a liver injury model induced by hepatic fibrosis. Sprague-Dawley (SD) rats were administered Dimethylnitrosamine (DMN) to induce liver injury, and the hepatoprotective effects of Cordyceps militaris extract powder intake were assessed by comparing changes in liver enzyme levels and histological observations. Rats injected with DMN were orally administered Cordyceps militaris extract powder at doses of 0, 125, 250, and 500 mg·kg-1·day-1 for three weeks. After three weeks of treatment, no significant differences were observed in hematological, clinical chemical, organ weight, gross examination, or microscopic examination between the DMN-alone group and the Cordyceps militaris extract powder-treated group. In conclusion, hepatoprotective effects against DMN-induced liver injury in SD rats treated with Cordyceps militaris extract powder were not observed under this study condition.

Case Report: Improvement of 3 Stroke Patients Through Integrative Medicine Based on Scalp Acupuncture (두침치료를 위주로 한 의한협진을 통해 호전된 뇌졸중 환자 3례의 증례보고)

  • Siyoung Song;Esther Jang;Joonyong Noh;Soomin Jo;Eunseo Kim;Geunjeong Kim;Kyungok Kim;Jaeuk Sul;Changsu Na
    • Korean Journal of Acupuncture
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    • v.41 no.3
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    • pp.118-126
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    • 2024
  • A stroke is a condition where an ischemic injury occurs in the brain tissue due to blockage or rupture of cerebral blood vessels. The damage to the brain nerve cells caused by a stroke is irreversible. Significant recovery is generally observed within the first six months after the onset, but the natural recovery rate decreases after six months. Therefore, intensive rehabilitation therapy is necessary within the first six months of the onset. This case report presents three cases of patients in the sequelae phase of stroke, where treatments based on integrative medicine system between traditional Korean medicine and Western medicine were applied. The treatments included scalp acupuncture from traditional Korean medicine and rehabilitation exercises and electrical therapy from Western medicine. In this case report, we evaluated the Manual Muscle Test (MMT), Modified Barthel Index (MBI), and the patients' subjective symptom interviews before and after the implementation of the integrative treatment. As a result, significant improvements in MMT and MBI were observed in acute stroke cases, whereas the improvement was minimal in cases with chronic progression. However, in all cases, the patients expressed high satisfaction with the treatment during the interviews.

Effect of nonlinear soil-structure interaction on the seismic performance of 3D isolated transformers when scaling the response spectra using the improved wavelet method

  • Mohammad Mahmoudi;Abbas Ghasemi;Shahriar Tavousi Tafreshi
    • Structural Engineering and Mechanics
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    • v.91 no.5
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    • pp.469-486
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    • 2024
  • Electric transformers are major components of electrical systems, and damage to them caused by earthquakes can result in significant financial loss. The current study modeled a three-dimensional (3D) isolated electrical transformer under horizontal and vertical records from different earthquakes. Instead of using fixed coefficients, an improved wavelet method has been used to create the greatest compatibility between the response spectra and the target spectrum. This method has primarily been used for dynamic analysis of isolated structures with spring-damper devices because it has shown greater accuracy in predicting the response of such structures. The effect of the nonlinear soil-structure interaction on the probability of transformer failure also has been investigated. Soil and structure interaction modeling was carried out using a beam on a nonlinear Winkler foundation. The effect of the nonlinear soil-structure interaction during dynamic analysis of transformers revealed that the greatest increase in the probability of transformer failure was in the fixed-base condition when the structure was located on soft soil. This intensified the response of the structure and increased the probability of transformer failure by up to 27% for far-field and up to 95% for near-field ground motions. A comparison of the results indicates that the use of 3D isolation systems in transformers in areas with soft clay that are subject to near-field ground motions can strongly reduce the probability of failure and improve the seismic performance of the transformer.