Discrete Cutting Force Model for 5-Axis Milling with Arbitrary Engagement and Feed Direction

5-axis machining operations bring new challenges for predicting cutting forces. Complex tool workpiece engagements and tool orientations make it difficult to adapt 3-axis process models for 5-axis operations. A new model is developed to predict cutting forces with arbitrary tool/workpiece engagement and tool feed direction. A discretization approach is used, in which the tool is composed of multiple cutting elements. Each element is processed to determine its effect on cutting forces, and global forces are determined by combining the elemental effects. Cutting tests are conducted to verify force predictions, where the tool/workpiece engagement is provided through a geometric software application

An Analysis of Engineering Design Graphics Journal Articles - Volumes 67-78

An analysis of articles published in the Engineering Design Graphics Journal (EDGJ) from 2003 - 2014 was conducted following the methodology used by Robert Chin in his 2003 study of articles published in the EDGJ from 1987 - 2002. Both studies look at feature-articles published in the EDGJ that were later indexed by ERIC (Educational Resources Information Center). ERIC provided abstract data that was compiled into a spreadsheet, which was then sorted and analyzed. The data collected from ERIC was also verified using the archives on the EDGJ website. The similar nature and analysis of the data gathered in the two studies allows direct comparisons to be made between the results of the studies

Occurrence of phthalates and organotins in sediments and water in Norway

NIVA has carried out a study on the occurrence of PVC additives such as phthalates, adipates and organotins in sediment, freshwater, seawater and domestic sewage in southern Norway on the commission of Norsk Hydro, Petrochemicals Division. The actual sampling areas were possible points of discharges from factories with a known use of either phthalates or organotins or both. In addition samples were taken from clean refernce areas and sewage plants. The largest source of phthalates seems to be receiving water to sewage treatment plants. 70 - 90% of the phthalates and adipates are retained in the sludge, which were dominated by DEHP. Background values from clean areas as lake Femunden were about 50 µg/kg of DEHP, and 80 µg/kg in marine sediments from Færder. Octyltin compounds were only found in sediments at two marine locations (Frierfjorden and Brattøya near Halden). The levels of phthalates in Norway are comparable to levels recorded in Sweden. It seems to be no contamination from industry which uses PVC additives in their production

Agent based demand flexibility management for wind power forecasting error mitigation using the SG-BEMS framework

The integration process of renewable energy sources (RES) and distributed energy resources (DER) into the power system, is characterized by concerns that originate from their stochastic and uncontrollable nature. This means that system operators require reliable forecasting tools, in order to ensure efficient and reliable operation. Accordingly, this paper proposes the use of demand flexibility, to counteract the RES forecasting errors. For this purpose, distributed and decentralized intelligence is used, via the SG-BEMS framework, to invoke demand flexibility in a timely and effective fashion, while taking into account the negative effects on the building occupants comfort. Lastly, numerical results from a simulated case of study are presented, which confirm that demand flexibility can be used to mitigate the magnitude of forecast errors

Physical activity and sleep in Icelandic adolescents

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesInngangur: Hreyfing og svefn eru mikilvægir áhrifaþættir heilsufars. Alþjóðlegar ráðleggingar mæla með því að börn og unglingar hreyfi sig að lágmarki 60 mínútur daglega af miðlungs eða mikilli ákefð og sofi í 8 til 10 klukkustundir á sólarhring. Tengsl hreyfingar og svefns meðal ungmenna eru ekki vel þekkt. Markmið rannsóknarinnar voru að meta: a) hversu hátt hlutfall 16 ára reykvískra ungmenna uppfyllir viðmið um hreyfingu og svefn, b) hvort tengsl séu milli hreyfingar og svefns og c) kynjamun á hreyfingu og svefni. Efniviður og aðferðir: Alls var 411 nemendum 10. bekkjar 6 grunnskóla í Reykjavík boðin þátttaka í rannsókninni vorið 2015. Gild gögn fengust frá 106 drengjum og 160 stúlkum. Hlutlægar og huglægar mælingar á hreyfingu og svefni voru gerðar með hröðunarmælum og spurningalistum. Niðurstöður: Um helmingur þátttakenda náði viðmiðum um hreyfingu samkvæmt niðurstöðum spurningalista. Þrátt fyrir að 51,9% teldu sig sofa nógu mikið náðu þó einungis 22,9% viðmiðum um ráðlagða svefnlengd samkvæmt hröðunarmælum. Engin tengsl fundust milli svefnlengdar og hreyfingar samkvæmt spurningalistum. Stúlkur hreyfðu sig marktækt meira en drengir á frídögum (p<0,01) samkvæmt hröðunarmælum en ekki var marktækur munur á meðaltali hreyfingar stúlkna og drengja yfir vikuna. Hvorki var marktækur kynjamunur á svefnlengd mældri með hröðunarmælum né spurningalista. Ályktun: Lífsstíll íslenskra ungmenna virðist ekki endurspegla viðmið opinberra aðila um daglega hreyfingu og svefn. Einungis 22,9% náðu viðmiðum um ráðlagðan svefntíma, og 11,3% uppfylltu bæði viðmið um hreyfingu og svefn.Introduction: Physical activity and sleep are major determinants of overall health. According to international recommendations, adolescents should engage in moderate to vigorous physical activity for at least 60 min each day and sleep eight to ten hours each night. The association between physical activity and sleep in adolescents is not well known. The aim of the study was to estimate a) the proportion of Icelandic adolescents that achieves recommended physical activity and sleep, b) if there is an association between physical activity and sleep patterns, and c) sex differences in physical activity and sleep. Material and methods: A total of 411 adolescents from the 10th grade in six schools in Reykjavik were invited to participate in a cross-sectional study in the spring of 2015. Valid data was obtained from 106 boys and 160 girls. Objective and subjective measures of physical activity and sleep were made by wrist-worn accelerometers and a questionnaire. Results: Almost half of the participants fulfilled the physical activity recommendations according to the questionnaire. Although 51.1% reported usually getting enough sleep, only 22.9% achieved the recommended sleep length according to objective assessment. No associations were observed between sleep and subjective physical activity. Girls had higher accelerometer-measured physical activity than boys on non-school days (p<0.01), but weekly averages were not different between sexes. Girls and boys did not differ in subjective or objective measures of sleep. Conclusion: The behavior of Icelandic adolescents does not reflect recommended amount of sleep and physical activity. Only 22.9% obtained the recommended sleep length and just 11.3% fulfilled recommendations of both sleep and physical activity.Ranní

A methodology for precision manufacture of a nozzle using hybrid laser powder-bed fusion: a case study

This paper presents a methodology for precision manufacture of a nozzle using the hybrid laser powder-bed fusion (L-PBF) technology. A new distortion predictive model for hybrid L-PBF was developed using finite element techniques. The model was validated against experimentally measured distortion using optical scanning. The validated model was utilised to mitigate distortion by applying additional stiffeners to the nozzle geometry where the distortion was reduced by 60% to acceptable tolerance of ±200 µm. Micro-milling trials were conducted to identify optimum cutting parameters delivering high material removal rates while maintaining the average surface roughness of less than 1 µm. Finally, a nozzle with reduced distortion and desirable surface finish was manufactured, which has been used in industrial research context for process and product development of food products

Severity of influenza A 2009 (H1N1) pneumonia is underestimated by routine prediction rules. Results from a prospective, population-based study.

Characteristics of patients with community-acquired pneumonia (CAP) due to pandemic influenza A 2009 (H1N1) have been inadequately compared to CAP caused by other respiratory pathogens. The performance of prediction rules for CAP during an epidemic with a new infectious agent are unknown. Prospective, population-based study from November 2008-November 2009, in centers representing 70% of hospital beds in Iceland. Patients admitted with CAP underwent evaluation and etiologic testing, including polymerase chain reaction (PCR) for influenza. Data on influenza-like illness in the community and overall hospital admissions were collected. Clinical and laboratory data, including pneumonia severity index (PSI) and CURB-65 of patients with CAP due to H1N1 were compared to those caused by other agents. Of 338 consecutive and eligible patients 313 (93%) were enrolled. During the pandemic peak, influenza A 2009 (H1N1) patients constituted 38% of admissions due to CAP. These patients were younger, more dyspnoeic and more frequently reported hemoptysis. They had significantly lower severity scores than other patients with CAP (1.23 vs. 1.61, P= .02 for CURB-65, 2.05 vs. 2.87 for PSI, P<.001) and were more likely to require intensive care admission (41% vs. 5%, P<.001) and receive mechanical ventilation (14% vs. 2%, P= .01). Bacterial co-infection was detected in 23% of influenza A 2009 (H1N1) patients with CAP. Clinical characteristics of CAP caused by influenza A 2009 (H1N1) differ markedly from CAP caused by other etiologic agents. Commonly used CAP prediction rules often failed to predict admissions to intensive care or need for assisted ventilation in CAP caused by the influenza A 2009 (H1N1) virus, underscoring the importance of clinical acumen under these circumstances.Icelandic Center for Research, Rannis 100436021 Landspitali University Hospital Science Fun

Case Report: Successful Implementation of Integrative Cognitive Remediation for Early Psychosis.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadMany individuals demonstrate functionally relevant impairment in neurocognition as well as social cognition early on in the course of their psychotic disorder. There is robust evidence supporting cognitive remediation as an effective treatment of cognitive dysfunction in schizophrenia. Increasingly it is accepted that earlier treatment is associated with better outcome and that it is important to systematically assess and treat cognitive dysfunction before the cognitive and functional disabilities are fully realized. However, the clinical availability of these interventions remains sparse. As we move forward with implementing evidence-based interventions into multi-component treatment for early psychosis, it is important to reflect on experience as well as evidence. This case report aims to describe the implementation of an integrative cognitive remediation program in coordinated specialty care (CSC) for early psychosis in Iceland and investigate whether the intervention is sustainable in a CSC setting. Data on the number of patients treated, facilitators trained, groups conducted, and funding was used to assess the sustainability. The results show that since initial implementation in 2016, the intervention has been routinely available as part of standard care, with over 100 patients having received the treatment. The report discusses key factors in the successful implementation of the program. Keywords: compensatory cognitive training; functional outcome; rehabilitation; schizophrenia; social cognition and interaction training.Research Fund Landspitali-The National University Hospital of Iceland 2017/2018 University of Icelan

Improved theory of laser-enhanced ionization in flames: comparison with experiment

An improved theory for laser enhanced ionization in flames has been developed for one‐ and two‐step laser excitations. The model gives an analytical expression for the sensitivity of the method for a given transition of any element. The theoretical expression is compared with experimentally measured signals for a number of elements and the agreement is found to be generally good