In-duct insertion loss of commonly used porous absorbers

Pettersson Matthew,Pearse John 한국소음진동공학회 2003 한국소음진동공학회 국제학술대회논문집 Vol.2003 No.8

The Gut Microbiome in an Ageing Host: Friend or Foe?

Sven Pettersson 한국식품영양과학회 2018 한국식품영양과학회 학술대회발표집 Vol.2018 No.10

Multiloop Control Strategy for Four-Wire Current Source Active Power Filter

Sami Pettersson,Mika Salo,Heikki Tuusa 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

Despite the fact that three-wire active power filters have been implemented using both voltage source and current source technology, the research of four-wire current source active power filters has been truly minimal. Only a few topologies have been presented over the years. This paper proposes a four-wire current source active power filter topology for improving the quality of supply in four-wire systems. The proposed topology is controlled using a multiloop control strategy suitable for a single-chip microcontroller implementation. The control strategy combines the load current feedforward connection and the cascaded closed-loop control of the supply currents and the capacitor voltages of the LC-type supply filter. By using the cascaded closed-loop control, the stability of the system can be achieved without the need to overdimension the supply filter. The performance of the proposed system is verified experimentally using a microcontroller controlled four-wire current source active power filter prototype rated for a 5 ㎸A load.

FRICTION AND WEAR PROPERTIES OF MICRO TEXTURED SURFACES IN BOUNDARY LUBRICATED SLIDING

U. PETTERSSON,S. JACOBSON 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10

In the present study, the friction and wear properties of boundary lubricated textured surfaces were investigated. The capability of textured surfaces to feed lubricant into the interface of a sliding contact and to isolate wear particles was studied and related to the properties of the textured surfaces. Well-defined surface textures were produced by lithography and anisotropic etching of silicon wafers. Different widths and distributions of parallel groves were manufactured and subsequently the wafers were PVD coated with thin wear resistant TiN or DLC coatings, retaining the substrate texture. The surfaces were evaluated in reciprocating sliding against a ball bearing steel ball under starved or boundary lubricated conditions.

Incorporating Embedded Q3 Agents - The Key For Volume Deployment of TMN

Gunnar Pettersson 한국통신학회 1997 Asia-Pacific Conference on Communications Vol.- No.-

Cervical cancer in the screening era: who fell victim in spite of successful screening programs?

B. Folke Pettersson,Kristina Hellman,Roxane Vaziri,Sonla Andersson,Ann-Cathrin Hellström 대한부인종양학회 2011 Journal of Gynecologic Oncology Vol.22 No.2

Objective: To compare profiles of a prescreening and screening cohort of women with cervical cancer regarding histopathology and clinical variables in order to identify those remaining at risk despite successful screening programs. By analyzing these profiles we hope to improve future screening methods. Methods: The prescreening and screening cohorts consisted of 5,046 and 1,174 women, respectively, treated for cervical cancer at the Department of Gynecological Oncology at Radiumhemmet, Karolinska University Hospital, during the periods 1944-1957 and 1990-2004. Results: Mean age increased from 48.9 years to 55.3 years in the cohorts treated 1944-1957 and 1990-2004, respectively. The percentage of patients older than 69 years was 5.4% and 27.3% in the prescreening and screening period, respectively. A shift towards earlier stages at diagnosis, a reduction of squamous cervical cancer and an increase of adenocarcinoma were observed in the screening cohort. The percentage of adenocarcinoma was about 6 times higher among younger patients. Cases of stump cancer and cervical cancer associated with pregnancy have declined. Eighty-seven women in the screening cohort had a history of treatment for in situ carcinoma by conization; 28% of these cases developed cervical cancer within one year after conization. Conclusion: The profile changed in the screening era indicating a need to refine screening for improved detection of in older women. This study, one of the largest clinical series of cervical cancer, provides an important baseline with which later studies can be compared to evaluate the effects of human papillomavirus vaccine and other important changes in this field. Objective: To compare profiles of a prescreening and screening cohort of women with cervical cancer regarding histopathology and clinical variables in order to identify those remaining at risk despite successful screening programs. By analyzing these profiles we hope to improve future screening methods. Methods: The prescreening and screening cohorts consisted of 5,046 and 1,174 women, respectively, treated for cervical cancer at the Department of Gynecological Oncology at Radiumhemmet, Karolinska University Hospital, during the periods 1944-1957 and 1990-2004. Results: Mean age increased from 48.9 years to 55.3 years in the cohorts treated 1944-1957 and 1990-2004, respectively. The percentage of patients older than 69 years was 5.4% and 27.3% in the prescreening and screening period, respectively. A shift towards earlier stages at diagnosis, a reduction of squamous cervical cancer and an increase of adenocarcinoma were observed in the screening cohort. The percentage of adenocarcinoma was about 6 times higher among younger patients. Cases of stump cancer and cervical cancer associated with pregnancy have declined. Eighty-seven women in the screening cohort had a history of treatment for in situ carcinoma by conization; 28% of these cases developed cervical cancer within one year after conization. Conclusion: The profile changed in the screening era indicating a need to refine screening for improved detection of in older women. This study, one of the largest clinical series of cervical cancer, provides an important baseline with which later studies can be compared to evaluate the effects of human papillomavirus vaccine and other important changes in this field.

In Vitro Osteogenic Differentiation of Human Mesenchymal Stem Cells from Jawbone Compared with Dental Tissue

Linda F. Pettersson,Paul J. Kingham,Mikael Wiberg,Peyman Kelk 한국조직공학과 재생의학회 2017 조직공학과 재생의학 Vol.14 No.6

Autologous bone transplantation is the current gold standard for reconstruction of jawbone defects. Bone regeneration usingmesenchymal stem cells (MSC) is an interesting alternative to improve the current techniques,which necessitate a second site of surgery resulting in donor site morbidity. In this study,we compared the osteogenic ability of jawboneMSC(JB-MSC) withMSC from tissues with neural crest origin, namely, the dental pulp, apical papilla and periodontal ligament. All four types ofMSC were isolated from the same patient (n = 3 donors) to exclude inter-individual variations.TheMSCgrowth and differentiation properties were characterized. The osteogenic differentiation potential in each group of cells was assessed quantitatively to determine if there were any differences between the cell types. All cells expressed the MSC-associated surface markers CD73, CD90, CD105, and CD146 and were negative for CD11b, CD19, CD34, CD45 and HLA-DR. All cell types proliferated at similar rates, exhibited similar clonogenic activity and could differentiate into adipocytes and osteoblasts. An alkaline phosphatase assay, OsteoImageTM assay for mineralization and qRT-PCR measuring the genes runx2, ALP and OCN, indicated that there were no significant differences in the osteogenic differentiation ability between the variousMSCs. In conclusion,we show that from a small segment of jawbone it is possible to isolate sufficient quantities of MSC and that these cells can easily be expanded and differentiated into osteoblasts. JB-MSC appear to be good candidates for future bone regeneration applications in the craniofacial region.

FEM simulation of a full-scale loading-to-failure test of a corrugated steel culvert

Amer Wadi,Lars Pettersson,Raid Karoumi 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.27 No.2

This paper utilizes 3D FEM to provide deeper insights about the structural behaviour of a 6.1 m span steel culvert, which was previously tested under extreme loading. The effect of different input parameters pertaining to the backfill soil has been investigated, where the structural response is compared to field measurements. The interface choice between the steel and soil materials was also studied. The results enabled to realize the major influence of the friction angle on the load effects. Moreover, the analyses showed some differences concerning the estimation of failure load, whereas reasons beyond this outcome were arguably presented and discussed.

SWIR-LWIR Photoluminescence from Sb-based Epilayers Grown on GaAs Substrates by using MBE

Laiq Hussain,Hakan Pettersson,Qin Wang,Amir Karim,Jan Anderson,Mehrdad Jafari,Jin Dong Song,Won Jun Choi,Il Ki Han,Ju Young Lim 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.11

Utilizing Sb-based bulk epilayers on large-scale low-cost substrates such as GaAs for fabricating infrared (IR) photodetectors is presently attracting significant attention worldwide. For this study, three sample series of GaAsxSb1x, In1xGaxSb, and InAsxSb1x with different compositions were grown on semi-insulating GaAs substrates by using molecular beam epitaxy (MBE) and appropriate InAs quantum dots (QDs) as a defect-reduction buffer layer. Photoluminescence (PL) signals from these samples were observed over a wide IR wavelength range from 2 m to 12 m in agreement with the expected bandgap, including bowing effects. In particular, interband PL signals from InAsxSb1x and In1xGaxSb samples even at room temperature show promising potential for IR photodetector applications.

The ‘Hot Cross Bun’ Sign is Not Always Multiple System Atrophy: Etiologies of 11 Cases

Christopher Young Way,David Pettersson,Amie Hiller 대한파킨슨병및이상운동질환학회 2019 Journal Of Movement Disorders Vol.12 No.1

Objective To clarify the specificity of the ‘hot cross bun’ sign (HCBS) for multiple system atrophy (MSA) in adult cerebellar ataxia or parkinsonism. Methods The radiologic information systems at an academic center and affiliated veterans’ hospital were queried using the keywords ‘hot cross bun,’ ‘pontocerebellar,’ ‘cruciate,’ ‘cruciform,’ ‘MSA,’ ‘multiple system atrophy,’ and ‘multisystem atrophy.’ Scans were reviewed by a neurologist and neuroradiologist to identify the HCBS. Subjects with the HCBS were reviewed by 2 neurologists to identify the most likely etiology of the patient’s neurologic symptoms. Results Eleven cases were identified. Etiologies included MSA (4 probable, 2 possible), hereditary cerebellar ataxia (3/11), probable dementia with Lewy bodies (1/11), and uncertain despite autopsy (1/11). Conclusion MSA was the most common etiology. However, 5 of the 11 patients did not have MSA. The most common alternate etiology was an undefined hereditary cerebellar ataxia (3/11).