Effect of surface roughness on friction behaviour of steel under boundary lubrication

The friction behaviour of grinded and polished surfaces was evaluated by using a reciprocal sliding tester under lubrication with PAO, PAO + ZnDTP and PAO + ZnDTP + MoDTC. Friction coefficients on the smooth surfaces showed higher values compared to those on the rough surfaces. For lubrication incorporating PAO and PAO + ZnDTP + MoDTC, friction coefficients on both the smoothest and the roughest surfaces decreased with sliding time. On the other hand, friction coefficients between these extremes decreased with sliding time. In this paper, the effects of surface roughness on friction behaviour are discussed

Monitoring of lung edema by microwave reflectometry during lung ischemia-reperfusion injury in vivo

It is still unclear whether lung edema can be monitored by microwave reflectometry and whether the measured changes in lung dry matter content (DMC) are accompanied by changes in PaO(2) and in pro-to anti-inflammatory cytokine expression (IFN-gamma and IL-10). Right rat lung hili were cross-clamped at 37 degrees C for 0, 60, 90 or 120 min ischemia followed by 120 min reperfusion. After 90 min (DMC: 15.9 +/- 1.4%; PaO(2): 76.7 +/- 18 mm Hg) and 120 min ischemia (DMC: 12.8 +/- 0.6%; PaO(2): 43 +/- 7 mm Hg), a significant decrease in DMC and PaO(2) throughout reperfusion compared to 0 min ischemia (DMC: 19.5 +/- 1.11%; PaO(2): 247 +/- 33 mm Hg; p < 0.05) was observed. DMC and PaO(2) decreased after 60 min ischemia but recovered during reperfusion (DMC: 18.5 +/- 2.4%; PaO(2) : 173 +/- 30 mm Hg). DMC values reflected changes on the physiological and molecular level. In conclusion, lung edema monitoring by microwave reflectometry might become a tool for the thoracic surgeon. Copyright (c) 2006 S. Karger AG, Basel

Wear prevention characteristics of binary oil mixtures

This work presents the results of wear prevention tests carried out with mixtures of a polyalphaolefin (PAO 6) and two esters (TMP-05 and Sunflower oil, SO), on a four-ball machine tester. Results show that esters are excellent wear reducers when they are mixed with a low viscosity polyalphaolefin. The optimum ester percentages in PAO 6 were 5% and 15% for TMP-05 and SO, respectively. Better results than in pure PAO 6 occurred in all mixtures. The addition of esters (less than 15%) to PAO 6 hardly changed volume viscosity

Effect of PAO-based γ-Fe2O3 and surfactant concentration on viscosity characteristic

This is a preliminary study on the viscosity characteristics of polyalphaolefin (PAO)- based γ-Fe2O3 under zero magnetic fields. By varying the concentration of magnetic nanoparticles (MNPs), PAO-based γ-Fe2O3 with different concentrations were synthesized by co-precipitation method. The effect of this factor on the viscosity characteristic of γ-Fe2O3 (< 30 nm) was investigated on the basic of a series of rheological measurement. The use of oleic acid (OA) as a coating agent and surfactant was also investigated by varying its concentration. The results show the concentration of MNPs and the amount of OA has obvious effect on viscosity characteristics of PAO-based γ-Fe2O3. In the case of comparison between the concentrations of MNPs, higher concentration of MNPs increased the viscosity of the PAO-based γ-Fe2O3 and exhibit nearly Newtonian behavior. The large amount of OA also exhibits the increment on viscosity characteristic of MNPs. The experimental data were compared with the Bingham and Casson model and the results revealed that the rheology of the polyalphaolefin (PAO)-based γ-Fe2O3 fitted the Casson model better

Szu-Feng Chen, Assistant Professor, Department of Theatre and Dance, travels to Singapore

Professor Szu-Feng Chen was invited by The Theatre Practice (TTP) in Singapore to create set and costume design for Lao Jiu: The Musical, its feature musical production for the Singapore Kuo Pao Kun Festival.I was invited by The Theatre Practice (TTP) in Singapore to create set and costume design for its feature musical production for Singapore Kuo Pao Kun Festival. Lao Jiu: The Musical, is a musical version of Kuo’s signature play. It was opened in July 2012 in memory of ten years of Kuo Pao Kun’s passing. Kuo Pao Kun was the pioneer and art educator of Singaporean theatre—awarded the National Culture Medallion in 1989, the Culture Award in 1992, Asean Cultural Award in 1993and the Excellence for Singapore Award in 2002. The festival is hosted by The Theatre Practice and supported by Singapore National Arts Council in honor of Kuo’s contribution to the Singapore performing arts

A Bayesian analysis of the 27 highest energy cosmic rays detected by the Pierre Auger Observatory

It is possible that ultra-high energy cosmic rays (UHECRs) are generated by active galactic nuclei (AGNs), but there is currently no conclusive evidence for this hypothesis. Several reports of correlations between the arrival directions of UHECRs and the positions of nearby AGNs have been made, the strongest detection coming from a sample of 27 UHECRs detected by the Pierre Auger Observatory (PAO). However, the PAO results were based on a statistical methodology that not only ignored some relevant information (most obviously the UHECR arrival energies but also some of the information in the arrival directions) but also involved some problematic fine-tuning of the correlation parameters. Here we present a fully Bayesian analysis of the PAO data (collected before 2007 September), which makes use of more of the available information, and find that a fraction F_AGN = 0.15^(+0.10)_(-0.07) of the UHECRs originate from known AGNs in the Veron-Cetty & Veron (VCV) catalogue. The hypothesis that all the UHECRs come from VCV AGNs is ruled out, although there remains a small possibility that the PAO-AGN correlation is coincidental (F_AGN = 0.15 is 200 times as probable as F_AGN = 0.00).Comment: MNRAS, accepted; 8 pages, 7 figure

Lubrication of DLC Coatings with Two Tris(pentafluoroethyl)trifluorophosphate Anion-Based Ionic Liquids

The lubrication of a Cr-DLC coating with ethyl-dimethyl-2-methoxyethylammonium tris(pentafluoroethyl)trifluoropho-sphate [(NEMM)MOE][FAP] and 1-butyl-1-methylpyrro-lidinium tris(pentafluoroethyl)trifluorophosphate [BMP] [FAP] ionic liquids (ILs) as 1 wt% additives to a polyalphaolefin (PAO 6) was studied. Zinc dialkyldithiophosphate (ZDDP) was also used as reference in order to evaluate the effectiveness of the ILs. Reciprocating ball-on-plate tribological tests at loads of 20 and 40 N were performed. The results showed that both ILs exhibited a friction reduction, especially at the lowest load tested. Antiwear properties were also improved; the PAO 6 + 1% [BMP][FAP] mixture was slightly better, close to the values for PAO 6 + 1% ZDDP. Scanning electron microscopy (SEM) images and X-ray photoelectron spectroscopy (XPS) analysis indicated that the additive–surface interaction was responsible for the tribological improvement

PENGARUH LINGKUNGAN KERJA TERHADAP KINERJA GURU DI MTs MADANI PAO-PAO

Abstract: The Effect of the Work Environment on Teacher Performance at MTs Madani Pao-PaoThis research aims to know how work environment on teacher performance at MTs Madani Pao-Pao as well as to know the influence between work environment to learn performance in MTs Madani Pao-Pao. This research use Quantitative Approach with Ex-post Facto type. Population of this research is 23 teacher at MTs Madani Pao-Pao and taken sample for the research is 12 teacher which teaching in MTs Madani Pao-Pao. Data collecting method of this research are documentation and questionnaire. Then, technique of data analysis used by researcher are descriptive analysis and inferensial analysis technique. From the calculation obtained tcount = 26, 146 whereas ttable = 1,812 for the level of significant 5%. So, it can be concluded that there are signifikan influence between work environment on teacher performance at MTs Madani Pao-Pao.  Abstrak: Pengaruh Lingkungan Kerja terhadap Kinerja Guru di MTs Madani Pao-PaoPenelitian ini bertujuan untuk mengetahui bagaimana lingkungan kerja dan kinerja guru di MTS Madani Pao-Pao serta untuk mengetahui pengaruh antara lingkungan kerja terhadap kinerja belajar di MTs Madani Pao-Pao. Penelitian ini menggunakan Pendekatan Kuantitatif tipe Ex-post Facto. Populasi dari penelitian ini adalah 23 guru di Mts Madani Pao-Pao dan diambil sampel untuk penelitian ini adalah 12 guru yang mengajar di MTS Madani Pao-Pao. Metode pengumpulan data dalam penelitian ini adalah dokumentasi dan angket. Kemudian, teknik analisis data yang digunakan peneliti yaitu teknik analisis deskriptif dan analisis inferensial. Dari perhitungan diperoleh thitung = 26, 146 sedangkan ttabel = 1,812 untuk taraf signifikasi 5%, Sehingga dapat disimpulkan bahwa terdapat pengaruh yang signifikan antara lingkungan kerja terhadap kinerja guru di Mts Madani Pao-Pao

Atmospheric benzene observations from oil and gas production in the Denver-Julesburg Basin in July and August 2014

High time resolution measurements of volatile organic compounds (VOCs) were collected using a proton-transfer-reaction quadrupole mass spectrometry (PTR-QMS) instrument at the Platteville Atmospheric Observatory (PAO) in Colorado to investigate how oil and natural gas (O&amp;NG) development impacts air quality within the Wattenburg Gas Field (WGF) in the Denver-Julesburg Basin. The measurements were carried out in July and August 2014 as part of NASA’s “Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality” (DISCOVER-AQ) field campaign. The PTR-QMS data were supported by pressurized whole air canister samples and airborne vertical and horizontal surveys of VOCs. Unexpectedly high benzene mixing ratios were observed at PAO at ground level (mean benzene = 0.53 ppbv, maximum benzene = 29.3 ppbv), primarily at night (mean nighttime benzene = 0.73 ppbv). These high benzene levels were associated with southwesterly winds. The airborne measurements indicate that benzene originated from within the WGF, and typical source signatures detected in the canister samples implicate emissions from O&amp;NG activities rather than urban vehicular emissions as primary benzene source. This conclusion is backed by a regional toluene-to-benzene ratio analysis which associated southerly flow with vehicular emissions from the Denver area. Weak benzene-to-CO correlations confirmed that traffic emissions were not responsible for the observed high benzene levels. Previous measurements at the Boulder Atmospheric Observatory (BAO) and our data obtained at PAO allow us to locate the source of benzene enhancements between the two atmospheric observatories. Fugitive emissions of benzene from O&amp;NG operations in the Platteville area are discussed as the most likely causes of enhanced benzene levels at PAO