The subject of the present paper is improving sound absorption properties and protecting the dust generation of ceramic fiber boards. The two‐microphone impedance tube method measured the sound ...absorption coefficient (SAC) of ceramic fiberboards (CFB) with different shapes and sizes. The wood veneer was used to cover the ceramic fiberboard (VCFB) surface to improve the wall's appearance and prevent dust generation. The step‐shaped ceramic fiberboards with veneer attached (VCFBS) revealed improved SAC (.98, 2000 Hz) compared with CFB and VCFB. The noise reduction coefficient (NRC) and sound absorption average showed a 100% improvement compared to CFB. The surface morphology and air permeability were analyzed using a scanning electron microscope and a capillary flow porometer to correlate with the findings. Furthermore, the porosity and pore diameter of the CFB were also studied to gain a comprehensive understanding of its acoustic properties and sound absorption capabilities. Statistical T‐tests revealed significant variations in the SAC (p ≤ .005). Besides, the obtained SAC was compared with other reported sound‐absorbing materials. These findings suggest that using step‐shaped ceramic fiberboard covered with a wood veneer can significantly absorb sound and improve the living environment. This novel approach offers potential advancements in sound‐absorbing materials for building construction.
•Studied effectiveness of steam explosion on wood cell walls.•Two different porous wood cell walls have studied.•Steam exploded wood shows better air permeability.•Steam exploded wood shows better ...sound absorption coefficient.•Correlated by ATIR-FTIR, XRD, FE-SEM and EDAX.
Steam explosion is a useful method to soften and dimensionally stabilizing wood. The effects of steam explosion at low pressure (6 bar) on wood cell walls are characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), capillary flow porometry and two-microphone transfer function. The average sound absorption coefficient (SAC) of treated Chinaberry samples on the cross-sectional surface exhibited significant improvement of 79% relative to control specimens over a wide frequency range of 250–6400 Hz. Whereas, a little increment SAC of 5% was observed in the case of Ginkgo wood. Color of steam-exploded woods became black due to chemical reactions in wood cell walls during the steam explosion. The air permeability, SAC and color change are correlated with the results of FTIR and XRD. These results suggest that steam explosion could be used to manufacture wood-based sound absorption board to control the acoustical housing environment.
Cross-laminated timber (CLT) is an increasingly popular building material due to its sustainability and structural performance. This study investigates the impact sound of CLT floor panels or square ...timber CLT, focusing on both lightweight and heavyweight impact sounds. The novelty lies in comparing four-floor coverings with different CLT panel configurations, including vinyl board attached to CLT floor panels, vinyl board with CLT-inserted air gap with gypsum board, and gypsum board with an air gap from CLT floor panels. The results demonstrate that vinyl board with CLT-inserted air gap with gypsum board effectively reduces the lightweight impact sound by 15.86 dB and heavyweight impact sound by 7.01 dB at 250 Hz. Moreover, t-test results exhibited a significant variation (p = ≤ 0.005) for lightweight impact sound and a non-significant variation (p = 0.092) for heavyweight impact sound. Additionally, adding an air gap with a gypsum board beneath CLT floors can reduce both impact sounds. This information can be helpful for architects and designers aiming to improve acoustic performance in a building.
아동기 집에 대한 장소애착 척도 개발과 타당화 연구 이진숙(Jin Suk Lee); 최병숙(Byung Sook Choi); 한지현(Ji Hyeon Han) ...
Korean Journal of child studies,
2009, Volume:
30, Issue:
6
Journal Article
Peer reviewed
Open access
This study developed the Place Attachment to Childhood Home Scale and evaluated its validity and reliability. Samples consisted of 418 college students of four universities. Data were collected by ...questionnaire based on retrospective questions about the childhood home. Factor analysis resulted in 5 dimensions of place attachment : affection, place identity, place rootedness, playfulness, and place dependence. Especially, playfulness was a unique finding. The result of confirmatory factor analysis supported the five-factor structure. There were also significant correlations among sub-factors. The reliability of the scale appeared high (Cronbach's ${\alpha}$ = .948). Criterion-related validity was confirmed by significant correlations of the present scale with Attachment Scale to Place (Hess, 1997) and the Inventory of Parent Attachment (Armsden & Greenberg, 1987).
This study explored the place attachment of college students to their home environments, suggesting valid factors and variables to explain their place attachment, and identify place attachment ...characteristics in two student groups with different housing backgrounds and conditions. The major data collection method for this survey was through a questionnaire. This study uses two data sets, one from the U.S. consisting of 352 college students' responses and the other from Korea consisting of 418 college students' responses. Through exploratory factor analysis and confirmatory factor analysis, nineteen items under five place attachment factors were verified as valid sub-concepts that explained respondents' place attachment to their home environments. The five factors were respectively labeled Affection, Rootedness, Identity, Restful Home, and Activities Dependence. The analysis showed that students' different housing backgrounds and current housing conditions, based on their cultural differences, significantly affected their place attachment to home environments. Demographic variables such as gender, grade level, living with family (including parents), and type of current housing were significant determinants affecting college students' place attachment to home environments. The results of this study cannot be generalized for the two cultures due to the limited samples, but it is meaningful to explore the place attachment characteristics of two student groups who have culturally different housing backgrounds and conditions.
이중조영에 의한 위 , 십이지장의 X 선학적 진단 최병숙; Byung Sook Choi
The Korean journal of gastroenterology,
01/1974, Volume:
6, Issue:
2
Journal Article
Peer reviewed
Levy and Granmark had introduced double contrast study in 1896 for the first time. Since Daval and Beclere had human experiment of double contrast air study, so many methods for diagnosis of ge.stric ...diseases are discovered and improved. 'Aiain valuable purpcses for double contrast study of stomach and duodenum are early diagncsis of stomach cBilcer and differectial diagncsis of ulcer forming malignancy frcm benigncy. In ="'d ticn to t4ese, differentiation of gastroauo"e.al defects, intrin-ic or extrins!c, is also v'orthwlii!e by tl;e metho3 of doub!e cc,ntrast air study of stomach and duodenum. Hvpotonic duodenography is exclusive of misinterpretation of duocenal non lesion in conventi,.nal barium study, as it attributes in cor firmation of nature, extention of lesion, and differer..iation betv;een intrinsic or extrinsic, cr duodenal or papillary lesion in origin, Hypotonic 3uodenogrzphy is helpful in carly diagnosis of disease and avoid misleading unneccessary fv.rther study or explorat- ory laparotomy.
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