• Advances in concrete construction
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• v.4 no.2
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• pp.123-143
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• 2016

Use of heavy fuel fly ash (HFFA) (diesel and cracked fuel) for power generation in Saudi Arabia has generated and accumulated large quantities of HFFA as a byproduct. In this research, HFFA is studied with the emphasis on the utilization of this waste material in concrete blocks and asphalt concrete mixes. Two types of mixes, one with low and other with high cement content, were studied for concrete blocks. Different mixes having varying percentages of HFFA (0% to 25%), as cement/sand replacement or as an additive, were studied. The performance of concrete blocks is evaluated in terms of compressive strength, water absorption, durability and environmental concerns. The results showed that blocks cannot be cast if more than 15% HFFA is used; also there is a marginal reduction in the strength of all the mixes before and after being exposed to the sulfate solution for a period of ten months. HFFA is studied in asphalt concrete mixes in two ways, as an asphalt modifier (3&5%) and as a filler (50%) replacement, the results showed an improvement in stiffness and fatigue life of mixes. However, the stability and indirect tensile strength loss were found to be high as compared to the control mix due to moisture damage, indicating a need of using antistripping agents. On environmental concerns, it was found that most of the concerned elements are within acceptable limits also it is observed that lower concentration of barium is leached out with the higher HFFA concentrations, which indicates that HFFA may work as an adsorbent for this leaching element.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.326-333
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• 2008

This study is objected by presenting preliminary data to revise the periodic replacement criteria of continuous welded rail (CWR) in using. In this study, it is investigated information resources for foreign standards, the cause and types of damage in welded rails and the track maintenance history of Seoul metro to analysis the correlation between rail failure and accumulated passing tonnage. Also, it is performed bending test for the laid welded rail reaching the periodic replacement criteria. In result, the correlation between rail failure and accumulated passing tonnage is not obvious and it is a lot of cases for the construction error of welded rail. Also, as a result of bending test of laid welded rail, according to reducing about $17{\sim}18%$ the bending fracture strength of rail, the laid welded rail reaching the periodic replacement criteria is well enough ensured for the load carrying capacity of rail.

• Journal of Life Science
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• v.32 no.10
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• pp.812-820
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• 2022

Depression is a psychiatric disorder characterized by depressed mood, anhedonia, fatigue, and altered cognitive function, leading to a decline in daily functioning. In addition, depression is a serious and common mental illness not only in an individual's life but also in society, so it must be actively treated. Autophagy is involved in the pathophysiological mechanism of mental illness. According to a recent study, it is known that autophagy-induced apoptosis affects neuroplasticity and causes depression and that antidepressants regulate autophagy. Autophagy is a catabolic process that degradation and removes unnecessary organelles or proteins through a lysosome. And, it is essential for maintaining cellular homeostasis. Autophagy is activated in stress conditions, and depression is a stress-related disease. Stress causes damage to cellular homeostasis. Recently, although the role of autophagy mechanisms in neurons has been investigated, the autophagy of depression has not been fully studied. This review highlights the new evidence for the involvement of autophagy in the pathophysiological mechanisms and treatment of depression. To highlight the evidence, we present results from clinical and preclinical studies showing that autophagy is associated with depression. Understanding the relevance of autophagy to depression and the limitations of research suggest that autophagy regulation may provide a new direction for antidepressant development.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.537-548
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• 2022

It is important to design the pavement thickness considering heavy-duty traffic loads, which can cause excessive stress and strain in the pavement. Port-rear roads and industrial roads have many problems due to early stress in pavement because these have a higher ratio of heavy loads than general roads such as national roads and expressways. Internationally, composite pavement has been widely applied in pavement designs in heavy-duty areas. Composite pavement is established as an economic pavement type that can increase the design life by nearly double compared to that of existing pavement while also decreasing maintenance and user costs. This study suggests a thickness design method for composite pavement using roller-compacted concrete as a base material to ensure long-term serviceability in heavy-duty areas such as port-rear roads and industrial roads. A three-dimensional finite element analysis was conducted to investigate the mechanical behavior and the long-term pavement performance ultimately to suggest a thickness design method that considers changes in the material properties of the roller-compacted concrete (RCC) base layer. In addition, this study presents a user-friendly catalog design method for RCC-base composite pavement considering the concept of linear damage accumulation for each container trailer depending on the season.

• Journal of Applied Biological Chemistry
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• v.59 no.3
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• pp.265-271
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• 2016

Recently, liver damage contributes to big percentage of the morbidity and mortality rates worldwide. Excessive intake of alcohol is one of the major causes of liver injury. When liver injury is repeated and becomes chronic, it leads to development of fibrosis and cirrhosis. In the liver, TGF-${\beta}$ is a profibrogenic cytokine, which participates in various critical events cause liver fibrosis. Seahorse (Hippocampus abdominalis) is a common traditional Chinese medicine and has been widely used for centuries. Seahorse has been known to have a variety of bioactivities, such as anti-oxidant, anti-fatigue, and anti-tumor. Peptide is one of the main compounds of seahorse. In this study, we isolated enzymatic hydrolysate from seahorse H. abdominalis by alcalase hydrolysis and investigated the effect of the hydrolysate on liver injury. In the present in vitro studies, the hydrolysate increases cell viability of Chang cells and protects Huh7 cells from ethanol toxicity. In addition, the hydrolysate inhibits TGF-${\beta}$-induced responses. In vivo studies show that the pretreatment of hydrolysate reduces alcohol-induced increases of serum Glutamic oxaloacetic acid transaminase and Glutamic pyruvate transaminase activities and increases liver weight and body weight. These results suggest that seahorse may have a hepatoprotective effect.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.1
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• pp.40-49
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• 1986

Crack, craze and void are common defects which may be found in the bulk of polymeric materials such as either themoplastics or thermosets. The healing phenomena, autohesion, of these defects are known to be a intrinsic material property of various polymeric materials. However, only a few experimental and theoretical investigations on crack, void and craze healing phenomena for various polymeric materials have been reported up to date [1, 2, 3]. This may be partly due to the complications of healing processes and lacking of appropriate theoretical developments. Recently, some investigators have been urged to study the healing phenomena of various polymenic materials since the significance of the use of polymer based alloys or composites has been raised in terms of specific strength and energy saving. In the earlier published reports [1, 2, 3, 4], the crack and void healing velocity, healing toughness and some other healing mechanical and physical properties were measured experimentally and compared with predicted values by utilizing a simple model such as the reptation model under some resonable assumptions. It seems, however, that the general acceptance of the proposed modeling analyses is yet open question. The crack healing processes seem to be complicate and highly dependent on the state of virgin material in terms of mechanical and physical properties. Furthermore, it is also strongly dependent on the histories of crack, craze and void development including fracture suface morphology, the shape of void and the degree of disentanglement of fibril in the craze. The rate of crack healing may be a function of environmental factors such as healing temperature, time and pressure which gives different contact configurations between two separated surfaces. It seems to be reasonable to assume that the crack healing processes may be divided in several distinguished steps like stress relaxation with molecular chain arrangement, surface contact (wetting), inter- diffusion process and com;oete healing (to obtain the original strength). In this context, it is likely that we no longer have to accept the limitation of cumulative damage theories and fatigue life if it is probable to remove the defects such as crack, craze and void and to restore the original strength of polymers or polymer based compowites by suitable choice of healing histories and methods. In this paper, we wish to present a very simple and intuitive theoretical model for the prediction of healed fracture toughness of cracked or defective polymeric components. The central idea of this investigation, thus, may be the modeling of behavior of chain molecules under healing conditions including the effects of chain scission on the healing processes. The validity of this proposed model will be studied by making comparisons between theoretically predicted values and experimentally determined results in near future and will be reported elsewhere.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1678-1727
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• 2006

This study was perfromed to develop the assessment guideline and endpoints for clinical trial with anticancer herbal medicine. The botanical products used to humans for long time may be applied to phase 3 clinical trial after submitting the evidences for safety and efficacy of them or completion of basic requirement of phase 1 and phase 2 for safety confirmation and dose determination. Syndrome improvement was chiefly evaluated by Zubrod and karnofsky(%) methods. We suggest the general clinical trial assessment with botanical products, by following assessment points, that is, tumor size for 50 points, survival fate for 10 points, major syndromes for 40 points. It is recommendable that the each symptom of Qi deficiency syndrome, blood deficiency syndrome and Qi stagnation syndrome was allocated by assessment points, Similarly, the each symptom was given the assessment points according to the severity of symptom, for example, slight for 3 points, moderate for 2 points and severe for 1 point in hepatocelluar carcinoma and lung cancer. Then, the efficacy of botanical products was evaluated by the difference between pre-treatment and post-treatment. Asking the neoplastic patients of questionnaire on physical, emotional, cognitive, social and role subjects availability, three more syndromes (Fatigue, Pain and Nausea/Vomit), quality of life(QOL) will be evaluated by GLM statistics. In addition, in case of lung cancer, 13 questions will be asked by the EORTC QLQ-C13 forms. As the assessment of endpoints for efficacy to reduce side effects induced by chemotherapy and radiotherapy, the data of image scanning and hemato-urinalysis can be usefully applied on immune response, weight loss, indigestion, hemopoietic damage and injury of liver and kidney, while the changes of syndromes of side effect can be evaluated by differentiation methods of Qi and blood and five viscera. However, it is still necessary to determine the ratio between scientific analytical method and Oriental differentiation method as well as confirm the Oriental assessment endpoints by clinical trial. In addition, we suggest the continuous development of assessment endpoints on other carcinomas except of hepatocelluar carcinoma and lung cancer in future.

• Journal of Korean Society of Disaster and Security
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• v.15 no.4
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• pp.11-20
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• 2022

The general non-destructive inspection method for anchor bolts in Korea applies visual inspection and hammering inspection, but it is difficult to check corrosion or fatigue cracks of anchor bolts in the part included in the foundation or in the part where the nut and base plate are installed. In reality, objective investigation is difficult because inspection is affected by the surrounding environment and individual differences, so it is necessary to develop non-destructive inspection technology that can quantitatively estimate these defects. Inspection of the anchor bolts of domestic road facilities is carried out by visual inspection, and since the importance of anchor bolts such as bridge bearings and fall prevention facilities is high, the life span of bridges is extended through preventive maintenance by developing non-destructive testing technology along with existing inspection methods. Through the development of this technology, non-destructive testing of anchor bolts is performed and as a technology capable of preemptive/active maintenance of anchor bolts for road facilities, practical use is urgently needed. In this paper, the possibility of detecting defects in anchor bolts such as corrosion and cracks and reliability were experimentally verified by applying the ultrasonic test among non-destructive inspection techniques. When the technology development is completed, it is expected that it will be possible to realize preemptive/active maintenance of anchor bolts by securing source technology for improving inspection reliability.