• Journal of the Korean Wood Science and Technology
• /
• v.15 no.3
• /
• pp.1-13
• /
• 1987

This study was carried out to investigate the variations of dimension and exterior shape of vessel elements, morphology of spiral thickening and ray-vessel pit in korean diffuse-porous woods (56 species, 18 families), The tangential pore diameter and vessel element length was increased, whereas the pore number per unit area($1mm^2$) was decreased from pith outwards. The tangential pore diameter was decreased but the length of vessel element was not changed from earlywood to latewood within an annual ring. However, the dimensional variations of vessel element was not able to be recognized among relative positions in peripheral variation. The exterior shape of vessel element could be classified into four types; Type 1 is without tail, Type 2 with ligulate tail, Type 3 with broad taper tail and Type 4 with the very short length between perforations. The distribution frequency of Type 2 and 3 was relatively high in comparision with the others. According to the prominence, distribution position and branched shape, the spiral thickenings could be divided into five types. The spiral thickenings occurred 52% in the species observed. Thus it was doubtful to consider the simple presence of spiral thickening as diagnostic index in diffuse-porous woods. The morphology of ray-vessel pit could be grouped as reticulate, scalariform, oval, linear and coalescent type. Most of species examined showed oval and linear type.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.6
• /
• pp.825-831
• /
• 2012

The retrofitting of a thickening unit process is widely considered in municipal wastewater treatment plants in Korea to enhance the anaerobic digestion efficiency. The authors examined the effect of feed concentration (2-34.1 g VS/L) and feed to microorganism (F/M) ratio (0.50-1.35 g VS/g VS) on anaerobic batch digestion of sewage sludge. Methane yield over 90 mL $CH_4/g$ $VS_{feed}$ was found at a feed concentration in the range of 12-26 g VS/L and a F/M ratio below 0.6 g VS/g VS. A high F/M ratio decreased methane yield and rate with oragnic acid accumulation. As sudden increase of sewage sludge concentration prior to anaerobic digestion would jeopardize the digester performance due to the rasied F/M ratio, gradual increase of the sludge feed concentration or an additional biomass retention in the digester is recommended.

• Journal of Korean Neurosurgical Society
• /
• v.55 no.5
• /
• pp.300-302
• /
• 2014

Hypertrophic pachymeningitis is an uncommon disorder that causes a localized or diffuse thickening of the dura mater. Recently, the possibility that IgG4-related sclerosing disease may underlie some cases of intracranial hypertrophic pachymeningitis has been suggested. We herein report the tenth case of IgG4-related intracranial hypertrophic pachymeningitis and review the previous literature. A 45-year-old male presented with left-sided focal seizures with generalization. Magnetic resonance imaging (MRI) revealed a diffuse thickening and enhancement of the right convexity dura matter and falx with focal nodularity. The surgically resected specimens exhibited the proliferation of fibroblast-like spindle cells and an infiltration of mononuclear cells, including predominantly plasma cells. The ratio of IgG4-positive plasma cells to the overall IgG-positive cells was 45% in the area containing the highest infiltration of plasma cells. On the basis of the above findings, IgG4-related sclerosing disease arising from the dura mater was suspected. IgG4-related sclerosing disease should be added to the pachymeningitis spectrum.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.6
• /
• pp.822-825
• /
• 2000

Lymphocytic infundibuloneurohypophysitis is a rare inflammatory disorder, which may be caused by autoimmune response, affecting the infundibulum and the posterior lobe of the pituitary gland. The authors present a 15-year-old man with central diabetes insipidus, whose sellar magnetic resonance imaging (MRI) showed a focal thickening of the infundibulum and loss of high signal of the normal neurohypophysis on T1-weighted images. The histopathological diagnosis was lymphocytic infundibuloneurohypophysitis. When a patient presents with central diabetes insipidus and infundibular thickening on brain MRI, this entity should be included in the differential diagnosis though it is very rare. The significance of this entity in treatment is that it is basically not a surgical one, and surgery is needed only for tissue diagnosis. Symptomatic treatment and observation make it regress spontaneously.

• Applied Chemistry for Engineering
• /
• v.8 no.4
• /
• pp.673-678
• /
• 1997

Associative acrylic thickeners were prepared by emulsion copolymerization using nonionic vinyl surfactant esters as an associative macromonomer and their rheological properties were investigated. The thickening efficiency was shown to depend on the chain length of therminal hydrophobe and degree of ethoxylation of VSE. increasing the content of VSE enhanced the efficiency of the resulting polymers as a thickener. It was attributed to the intermolecular association of terminal hydrophobes of associative thickener in aqueous solution. The chain transfer agent caused to reduce the molecular weight of associative thickener, resulted in decrease of thickening efficiency.

• Tuberculosis and Respiratory Diseases
• /
• v.76 no.1
• /
• pp.42-45
• /
• 2014

An immunoglobulin G4 (IgG4)-related disease is a recently emerging entity, and a few cases of IgG4-related disease in lung and pleura have been reported. Herein, we report the case of a 74-year-old man with IgG4-related disease of lung and pleura, clinically suspicious of malignant mesothelioma. Chest computed tomography showed diffuse nodular pleural thickening, and microscopic finding disclosed diffuse thickening of visceral pleura with infiltrations of many lymphoplasma cells with increased number of IgG4-positive plasma cells and a few multinucleated giant cells. It is important for pathologists and clinicians to recognize this rare entity and its histologic finding, because it can be confused with malignant tumors on the radiologic examination although it can be treated with steroid therapy.

• Investigative Magnetic Resonance Imaging
• /
• v.20 no.1
• /
• pp.75-79
• /
• 2016

We report a case of perivalvular abscess in a 66-year-old man with infective endocarditis, diagnosed by late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) imaging. No clinical features suspicious of infective endocarditis were noted, however, transthoracic echocardiography revealed non-specific echogenic focal wall thickening at mitral-aortic intervalvular fibrosa. Perivalvular abscess in the aortic valve was demonstrated as focal wall thickening between the anterior mitral leaflet and the non-coronary cusp of the aortic valve with peripheral enhancement and central low signal intensity on LGE CMR imaging. Other features suggestive of infective endocarditis, such as neither vegetation nor valvular perforation were present. The perivalvular abscess did not grow after intensive intravenous antibiotics therapy, and the patient was discharged without surgical treatment. CMR with LGE provided an early accurate diagnosis of perivalvular abscess. The diagnosis of perivalvular abscess using LGE CMR imaging was not previously reported in Korea.

• Journal of Korean Society of Water and Wastewater
• /
• v.20 no.5
• /
• pp.677-684
• /
• 2006

Electro-flotation(EF), a novel sludge thickening method, could improve the dewaterability of activated sludge. The gas(microbubbles) generated during EF decreased the solid-liquid separation time below 1/5 of the time required for gravity sedimentation. In addition, over 90% of the sludge volume reduction could be achieved by EF although the settling characteristics of the sludge was very poor. The SRF(specific resistance to filtration) of the thickened sludge by EF was much lower than that of the sludge thickened by gravity sedimentation. The SRF of the thickened sludge decreased exponentially with increase of gas generation rate of the EF system. Gas generation rate could be controlled by varying the current density of the electrode. Degasing of the microbubbles by vigorous mixing of the thickened sludge layer deteriorated the dewaterability of the sludge. Therefore, it is obvious that the gas bubbles entrapped in the thickened sludge play a key role in the observed dewaterability improvement.

• Childhood Kidney Diseases
• /
• v.7 no.1
• /
• pp.91-95
• /
• 2003

The nephrotic syndrome is characterized by generalized edema, hypoproteinemia(<2 g/dL), proteinuria(>40 $mg/m^2/hr$), and hypercholesterolemia(>200 mg/dL). It is reported that hypoalbuminemia, which is one of the four diagnostic criteria of the nephrotic syndrome, is associated with gallbladder wall thickening. An explanation for the thickened wall in hypoalbuminemic states is the accumulation of fluid in the subserosal layer of the gallbladder wall which contains the most areolar tissue. This report describes a patient who was initially diagnosed with the nephrotic syndrome at the age of 4 and subsequently developed acute acalculous cholecystitis at the age of 5.8 with an albumin level of 1.3 g/dL. The patient responded to fluid therapy, nasogastric suction, and broad spectrum antibiotics.

• The Korean Journal of Rheology
• /
• v.9 no.1
• /
• pp.6-15
• /
• 1997

계면활성제용액에 서로 다른 기능을 하는 두 종류의 첨가제를 투입하여 미셀의 미 세구조 전이현상을 규명하였다. 양이온 계면활성제는 CMC 이상의 농도에서 2단계의 미세 구조 전이거동을 나타낸다. 우선 구형 미셀은 첨가제의 투입에 의하여 표면에서의 친수성기 간의 반발력이 감소됨으로써 실린더형 또는 디스크형미셀로 전이가 일어난다. 더욱 농도가 증가하면 이방성을 가지는 실린더형 미셀간의 중첩 또는 hooking 현상에 의한 두 번째 전 이가 일어난다. 이때 미셀 용액은 흔히 점탄성을 나타내거나 확연한 비뉴톤성 유체거동을 나타낸다. 본 연구에선 heptanol의 화확구조적 차이가 물성에 나타내는효과를 규명하고 wormlike 미셀을 형성하는 MaSal에 의한 점탄성 거동을 살펴보았다. Heptanol의 화학구조 의 영향을 보면 약친수성기인 OH기가 알킬그룹과 나란하게 존재하여 밀집된 구조를 가지 기 쉬운 primary heptanol이 가장효과적으로 미세구조 전이를 유도함을 관찰하였다. 다른 이성질 hetanol의 경우 secondary heptanol이 teriary heptanol에 비하여 효과적임을 보이지 만 화학재할수 있는 농도범위가 매우 좁아 대부분 영역에서 비뉴톤성거동을 나타냄을 확인 하였다. 즉 NaSal를 사용한 경우 실린더형 미셀이 존재할 수 있는농도범위가 매우 좁아 대 부분 영역에서 비뉴톤성 거동을 나타냄을 확인하였다. 즉 NaSal 이 첨가된 용액은 선형점탄 성거동을 보이며 몰비가 증가함에 따라 scission 과정이 관찰되었다. 또한 몰농도비에 따라 항복응력과 shear thickening 특징을 보이는데 이는 흐름장의 세기에 따라 미세구조 변화가 일어나기 때문이다.