• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.38 no.2 s.115
• /
• pp.52-60
• /
• 2006

Environment-friendly shock-absorbing materials were made of wastepaper such as Korean old corrugated containers(KOCC) and Korean old newsprint (KONP) with a vacuum forming method. The plate-like cushioning materials made of KOCC and KONP respectively by vacuum forming showed superior shock-absorbing properties with lower elastic moduli compared to expanded polystyrene (EPS) and pulp mold. Even though the plate-like materials had many free voids in their fiber structure, their apparent densities (${\approx}0.1g/cm^3$) were a little higher than that of EPS (${\approx}0.03g/cm^3$) and much lower than that of pulp mold(${\approx}0.3g/cm^3$). However, the elastic moduli of the cushioning materials made of wastepaper were much lower than that of EPS or pulp mold. This finding implies that the cushioning materials made of KOCC fibers containing more lignin than KONP show better shock-absorbing properties than KONP. Moreover, the cushioning materials made of KOCC and KONP respectively showed greater porosity than pulp mold. The addition of cationic starch to the cushioning materials contributed to the increase in the elastic modulus to the same level as that of EPS. Furthermore, the deterioration in fiber quality by repeated use of wastepaper played a positive role in improving shock-absorbing ability.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.38 no.2 s.115
• /
• pp.61-71
• /
• 2006

Environment-friendly shock-absorbing (cushioning) materials were made using a vacuum forming method from waste wood collected from local mountains in Korea. The waste wood was pulped by thermomechanical pulping. The TMP cushions showed superior shock-absorbing properties with lower elastic moduli compared to EPS(Expanded Polystyrene) and pulp mold. Even though the TMP cushions made using at different suction times had many free voids in their inner fiber structures, their apparent densities were a little higher than EPS and much lower than pulp mold. The addition of cationic starch improved elastic modulus of the TMP cushions without increasing the apparent density, which was different from surface sizing with starch. The porosity of the TMP cushions was a little greater than EPS and much less than pulp mold. Finally, the TMP cushions have great potential to endure external impacts occurring during goods distribution.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.48 no.2
• /
• pp.20-27
• /
• 2016

Ethylene gas is a natural hormone that directly affects the freshness of agricultural products, so it is very important for the maintenance of freshness to remove ethylene gas from corrugated board boxes. Many methods for the removal of this and other gases have been reported. In this study, the utilization of an absorbent using activated carbon was adopted for the removal of ethylene gas from a corrugated board box. Activated carbon powders were prepared by grinding in a laboratory and were used to treat the surface and to laminate paperboards with a starch solution. The ethylene gas absorption was evaluated by using a gas chromatography to measure the residual ethylene gas concentration. About 60% of the ethylene gas was absorbed by the activated carbon itself. However, the paperboards that were surface-treated and laminated with starch and activated carbon showed lower than 20% ethylene gas absorption. This was because the starch and smaller particles of activated carbon blocked the surface pores of activated carbon particles. Therefore, either the use of the binders must be minimized for the surface treatment of paperboards, or activated carbon packs can be used as absorbents in corrugated boxes.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.48 no.2
• /
• pp.5-12
• /
• 2016

White waste papers are very important resources in the paper industry, but their use is limited because of the residual of fluorescent whitening agent (FWA). So the removal of FWAs from waste paper is an important task in the recycling process to improve the use of recycled resources. In this study, we focused on the FWAs used for surface treatments and carried out physical and chemical treatments to remove them from white waste papers. The white waste papers were disintegrated with a surfactant in different pH and temperature conditions, and then handsheets were made for the measurement of the fluorescence index, which is proportional to the amount of FWAs on papers. The effect of the flotation process on the removal of FWAs after disintegration was also investigated. The fluorescence index decreased as the disintegration time increased, but over a relatively long time, the fluorescence index increased again, which indicated the readsorption of the FWAs detached from the cellulosic fibers of the white waste papers. The lowest fluorescence index was shown when the waste papers were disintegrated with a 0.3% surfactant addition at pH 10 and at $45^{\circ}C$. However, the flotation treatment was not effective, because the flotation induced contact between the detached FWAs and the cellulosic fibers, and re-adsorption occurred.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.5
• /
• pp.63-71
• /
• 2012

This study was carried out to investigate pulping properties of the forest biomass arising from the national forest management operation. The forest biomass was collected and classified into many groups according to their species and age. After the chips were made from the forest biomass, the measurement of chip size and chemical analysis were performed. To make the pulps from the forest biomass, the kraft pulping was applied and thereafter the physical and optical properties of kraft pulps were measured. The pulp fibers from the forest biomass had the similar mean fiber length, but their properties became different according to wood species and ages. Differently from the other species, kraft pulps from chestnut wood had the highest kappa number. Acacia, paulownia and chestnut woods made kraft pulps with lower tensile strength and brightness than the others. It could be concluded that acacia, paulownia and chestnut woods must be screened out in order to make a good quality of kraft pulps while being collected during Forest Management Operation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.41 no.4
• /
• pp.43-51
• /
• 2009

Paper mill sludges are discharged around 870,000 M/T annually. Only 30% of the paper mill sludge have been recycled and the rest has been disposed by land fill, incineration, ocean abandonment and other ways. Because of overall prohibition of sludge disposal by London Dumping Convention in 2012, a urgent counter measure for paper mill sludge must be provided. In this paper, some basic experiments were carried out to develop a tray cell pot using paper mill sludge for increasing the recycling potential of the wasted sludge. To establish the manufacturing parameters, the tray cell pots were made with three types of materials including virgin pulp, old news paper and corrugated board mixed in a blend tank of a molding machine. The bending force and moisture content of the produced tray cell pots was measured to confirm the application capability. The tray cell pot could be manufactured under the condition of over 20% of virgin pulp, 40% of old news paper added. However, the corrugated board could not be used because of the glutinous substance included. The produced tray cell pot absorbed water very easily and the bending force decreased rapidly. The waterproof material must be used to applicate the produced tray cell pot in plant growing fields.

• Journal of Chest Surgery
• /
• v.29 no.1
• /
• pp.107-111
• /
• 1996

Persistent bronchopleural fistula (BPF) still presents a troublesome therapeutic challenge and demands an aggressive approach when conventional measures fail. A 50-year-old man had a rigtlt pneumonectomy for far-advanced pulmonary tuberculosis with the development of postopneumonectomy empyema and BPF 1 month postoperatively in October 1 81. The condition was managed with BPF closure and the Clagett procedure, which failed with the recurrence of BPF and empyema, followed by a spontaneous open window at about 1 year port:operatively. The BPF, which had been aggravated to a large size, was managed by the closure and obliteration of the empyema cavity using a Pectoralis-skin pedicled flap 13 years postoper atively on Jul, 1994. The BPF was controlled by the procedure, and the patient, with improved respiratory symptom, was discharged 43 days postoperatively. We conclude that the use of myocutaneous flap Is an effective procedure for the closure of a large BPF. The surgical technique of the pedicled flap operation is described and the case is reported.

• The Korean Journal of Cytopathology
• /
• v.16 no.1
• /
• pp.18-24
• /
• 2005

The objective of this study was to ascertain whether or not the high-risk human papillomavirus (HPV) test, when coupled with Papanicolaou (Pap) smears, would prove useful in the screening and management of patients in whom abnormal Pap smear results had been obtained. Concomitant high-risk HPV detection using the hybrid capture II test and colposcopy with a Pap smear were performed with 176 patients, all of whom had been screened for both cervical carcinoma and precancerous lesions. We concomitantly performed colposcopies on these patients. Upon the follow-ups, the histologic diagnoses of these patients were confirmed via either biopsy or hysterectomy. The rate of high-risk HPV detection was correlated with cytologic diagnoses and colposcopic findings. The group composed of the high-risk HPV-positive ASCUS patients exhibited a 55.7% rate of cervical intraepithelial neoplasia (CIN), a significantly higher rate than the 7.5% result obtained in the high-risk HPV-negative ASCUS group. HPV test showed high sensitivity (87%) and low specificity (62.6%) in detection of CIN and colposcopy also showed high sensitivity (88%) and low specificity (22%). Any combination of these tests improve sensitivity, but not specificity. High-risk HPV tests, when coupled with Pap smears, constituted a useful triage approach with regard to colposcopy-directed biopsies in patients in whom a cytologic diagnosis of ASCUS had been rendered.

• The Korean Journal of Cytopathology
• /
• v.8 no.2
• /
• pp.135-142
• /
• 1997

Mucoepidermoid carcinoma is the most common malignant neoplasm of the salivary gland, compring between 30 and 40%. Fine needle apsiration cytology was performed in five patients with mucoepidermoid carcinoma. The patients consisted of three males aged of 42, 48, and 60 years, and two females aged 36, and 56 years. The primary tumor sites were the parotid gland in four patients and the submandibular gland in the rest one. The histologic grades were low in one patient, intermediate in two patients and high in other two. In our experience, the common cytologic findings of low grade subtype were predominent mucous cells with some intermediate cells in an abundant mucinous background. The cytologic findings of intermediate grade subtype were predominant clusters of intermediate cells with or without mucous cells in an abundant mucinous background. And the cytologic findings of high grade subtype were predominant clusters of epidermoid cells with intermediate cells in a bloody background. Cytologic pleomorphism and atypia were more severe in high grade than low and intermediate grade, and nucleoli were more frequently noted in epidermoid cells. In low grade, it is very difficult to decide the benignancy or malignancy of the tumor. In fact, the presence of mucous cells in a mucinous background should rule out any other type of well differentiated carcinoma.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.11 no.2
• /
• pp.66-74
• /
• 2008

In recent years, the view centered conservation for eco-system is getting important rather than development from human oriented perspective. As a result, the concept "Sustainable development", that is seeking harmony between conservation and development, appeared so that we researched distribution and status of vascular plants a site of project in the Bukkyungnam substation. The main findings from the study is as follows. The vascular plants a site of project in the Bukkyungnam substation area was listed 435 taxa; 93 families, 269 genera, 377 species, 1 subspecies, 51 varieties and 6 forms. Specific plant species by floral region were total 25 taxa; Acer palmatum (Planted species), Asperula lasiantha in Class III, Caryopteris incana, Cirsium schantarense in Class II, 21 taxa (Dryopteris erythrosora, Chloranthus japonicus, Salix glandulosa, Alnus hirsuta, Quercus variabilis, Ulmus parvifolia, Clematis patens, Rubus hirsutus, Euphorbia pekinensis, Cayratia japonica, Grewia biloba var. parviflora, Vaccinium oldhami, Microstegium japonicum, Hosta capitata, Polygonatum falcatum, etc.) in Class I. Based on the list of Korean endemic plants, 10 taxa were recorded; Cephalotaxus koreana, Populus tomentiglandulosa (Planted species), Indigofera koreana, Forsythia koreana (Planted species), Paulownia coreana (Planted species), Asperula lasiantha, Weigela subsessilis, Adenophora triphylla var. hirsuta, Carex okamotoi, Lilium amabile and based on the list of the rare plants by the Forest ResearchInstitute, 2 taxa were recorded in the studied areas; Lilium callosum (Preservation priority order; No. 191), Aristolochia contorta (No. 151). The naturalized plants in this site were 13 families, 22 genera, 28 taxa and naturalization rate was 6.4% of all 435 taxa vascular plants.