NEW FRICTION DURABLE ADDITIVE TECHNOLOGY AND ITS APPLICATION IN AUTOMATIC TRANSMISSIONS

Ovaj rad prikazuje razvoj tehnologije novih aditiva koja omogućuje formulaciju fluida za automatske prijenosnike (ATF-Automatic Transmission Fluids) na osnovi mineralnih ulja sa značajno poboljšanom otpornošću na trenje. U radu se uspoređuju performance trenja tehnologije novih aditiva kod komercijalno dostupnih ATF-a u Europi, Aziji i Sjevernoj Americi pri industrijski standardnim testovima trenja kao što su SAE No’2 rig (SAE No\u272 mjerna oprema) i Low Velocity Friction Apparatus (aparatura za ispitivanje trenja pri niskim brzinama). Isto tako, u radu se razmatraju primjeri još većih tehničkih izazova koje postavljaju posljednje ATF specifikacije u uvjetima još naglašenije oksidacije, trošenja, ekstremnih pritisaka, otpornosti na trenje, kapaciteta okretnog momenta i antikorozijskih zahtjeva, te se performance nove tehnologije aditiva otpornih na trenje uspoređuju s ostalim dostupnim ATF tehnologijama na nekim od spomenutih područja. Performance fluida otpornih na trenje koje su omogućene pomoću tehnologije novih aditiva mogu se primijeniti kod čitavog niza automatskih prijenosnika, npr. mokrih spojki za pokretanje, spojki pretvarača okretnog momenta, prijenosnika s dvostrukim spojkama i posljednje generacije automatskih prijenosnika sa šest, sedam, i osam stupnjeva prijenosa.This paper reports the development of a new additive technology allowing formulation of mineral oil based Automatic Transmission Fluids (ATFs) with significantly improved friction durability. The paper compares friction performance of the new additive technology with commercially available European, Asian and North American style ATFs in industry standard friction tests such as the SAE No’2 rig and the Low Velocity Friction Apparatus. The paper also considers examples of the broader technical challenges posed by the latest ATF specifications in terms of more stringent oxidation, wear, extreme pressure, friction durability, torque capacity and anti-corrosion requirements, and compares the performance of the new friction durable ATF technology with other commercially available ATFs in some of these areas. The fluid friction durability performance offered by this new additive technology is applicable in a variety of automatic transmission hardware, e.g. wet starting clutches, torque converter clutches, dual clutch transmissions and the latest generation six-, seven- and eight-speed step type automatic transmissions

Variation in chemical composition and volatility of oxygenated organic aerosol in different rural, urban, and mountain environments

The apparent volatility of atmospheric organic aerosol (OA) particles is determined by their chemical composition and environmental conditions (e.g., ambient temperature). A quantitative, experimental assessment of volatility and the respective importance of these two factors remains challenging, especially in ambient measurements. We present molecular composition and volatility of oxygenated OA (OOA) particles in different rural, urban, and mountain environments (including Chacaltaya, Bolivia; Alabama, US; Hyytiälä, Finland; Stuttgart and Karlsruhe, Germany; and Delhi, India) based on deployments of a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-CIMS). We find on average larger carbon numbers (nC) and lower oxygen-to-carbon (O : C) ratios at the urban sites (nC: 9.8 ± 0.7; O : C: 0.76 ± 0.03; average ±1 standard deviation) compared to the rural (nC: 8.8 ± 0.6; O : C: 0.80 ± 0.05) and mountain stations (nC: 8.1 ± 0.8; O : C: 0.91 ± 0.07), indicative of different emission sources and chemistry

Low sensitivity of a urine LAM-ELISA in the diagnosis of pulmonary tuberculosis

<p>Abstract</p> <p>Background</p> <p>The development and evaluation of rapid and accurate new diagnostic tools is essential to improve tuberculosis (TB) control in developing countries. In a previous study, the first release of a urine LAM-ELISA by Chemogen (Portland, USA) has been evaluated with a promising sensitivity and specificity for the diagnosis of pulmonary TB. In the present study, the now commercially available assay has been clinically assessed regarding its diagnostic value alone and in combination with clinical co-factors.</p> <p>Methods</p> <p>The test was applied to two urine samples from 291 consecutively enrolled Tanzanian patients with suspected pulmonary tuberculosis. The participants were subsequently assigned to classification groups according to microbiological, clinical and radiological findings at recruitment and during a maximum follow up period of 56 days.</p> <p>Results</p> <p>Only 35 out of 69 pulmonary TB cases -confirmed by smear microscopy and/or solid culture and/or liquid culture- showed at least one positive LAM-ELISA result (sensitivity 50.7%). The sensitivity was noticeably higher in females (66.7%) and in HIV positive participants (62.0%). The specificity amounted to 87.8% and was determined in participants with negative results in all microbiological tests and with sustained recovery under antibiotic treatment at day 56. Correlation with urinalysis revealed that proteinuria was significantly and positively associated with LAM-positivity (<it>P </it>= 0.026).</p> <p>Conclusion</p> <p>This commercially available generation of LAM-ELISA does not appear to be useful as an independent diagnostic test for pulmonary tuberculosis. The question whether the assay is suitable as a supplemental device in the diagnosis of HIV-associated TB, requires further investigations.</p

Reference Ranges for the Clinical Laboratory Derived from a Rural Population in Kericho, Kenya

The conduct of Phase I/II HIV vaccine trials internationally necessitates the development of region-specific clinical reference ranges for trial enrolment and participant monitoring. A population based cohort of adults in Kericho, Kenya, a potential vaccine trial site, allowed development of clinical laboratory reference ranges. Lymphocyte immunophenotyping was performed on 1293 HIV seronegative study participants. Hematology and clinical chemistry were performed on up to 1541 cohort enrollees. The ratio of males to females was 1.9∶1. Means, medians and 95% reference ranges were calculated and compared with those from other nations. The median CD4+ T cell count for the group was 810 cells/µl. There were significant gender differences for both red and white blood cell parameters. Kenyan subjects had lower median hemoglobin concentrations (9.5 g/dL; range 6.7–11.1) and neutrophil counts (1850 cells/µl; range 914–4715) compared to North Americans. Kenyan clinical chemistry reference ranges were comparable to those from the USA, with the exception of the upper limits for bilirubin and blood urea nitrogen, which were 2.3-fold higher and 1.5-fold lower, respectively. This study is the first to assess clinical reference ranges for a highland community in Kenya and highlights the need to define clinical laboratory ranges from the national community not only for clinical research but also care and treatment

Population-Based Biochemistry, Immunologic and Hematological Reference Values for Adolescents and Young Adults in a Rural Population in Western Kenya

BACKGROUND: There is need for locally-derived age-specific clinical laboratory reference ranges of healthy Africans in sub-Saharan Africa. Reference values from North American and European populations are being used for African subjects despite previous studies showing significant differences. Our aim was to establish clinical laboratory reference values for African adolescents and young adults that can be used in clinical trials and for patient management. METHODS AND FINDINGS: A panel of 298, HIV-seronegative individuals aged 13-34 years was randomly selected from participants in two population-based cross-sectional surveys assessing HIV prevalence and other sexually transmitted infections in western Kenya. The adolescent (/=18 years) ratio and the male-to-female ratio was 1ratio1. Median and 95% reference ranges were calculated for immunohematological and biochemistry values. Compared with U.S-derived reference ranges, we detected lower hemoglobin (HB), hematocrit (HCT), red blood cells (RBC), mean corpuscular volume (MCV), neutrophil, glucose, and blood urea nitrogen values but elevated eosinophil and total bilirubin values. Significant gender variation was observed in hematological parameters in addition to T-bilirubin and creatinine indices in all age groups, AST in the younger and neutrophil, platelet and CD4 indices among the older age group. Age variation was also observed, mainly in hematological parameters among males. Applying U.S. NIH Division of AIDS (DAIDS) toxicity grading to our results, 40% of otherwise healthy study participants were classified as having an abnormal laboratory parameter (grade 1-4) which would exclude them from participating in clinical trials. CONCLUSION: Hematological and biochemistry reference values from African population differ from those derived from a North American population, showing the need to develop region-specific reference values. Our data also show variations in hematological indices between adolescent and adult males which should be considered when developing reference ranges. This study provides the first locally-derived clinical laboratory reference ranges for adolescents and young adults in western Kenya

The Switchgrass Genome: Tools and Strategies

Switchgrass ( L.) is a perennial grass species receiving significant focus as a potential bioenergy crop. In the last 5 yr the switchgrass research community has produced a genetic linkage map, an expressed sequence tag (EST) database, a set of single nucleotide polymorphism (SNP) markers that are distributed across the 18 linkage groups, 4x sampling of the AP13 genome in 400-bp reads, and bacterial artificial chromosome (BAC) libraries containing over 200,000 clones. These studies have revealed close collinearity of the switchgrass genome with those of sorghum [ (L.) Moench], rice ( L.), and (L.) P. Beauv. Switchgrass researchers have also developed several microarray technologies for gene expression studies. Switchgrass genomic resources will accelerate the ability of plant breeders to enhance productivity, pest resistance, and nutritional quality. Because switchgrass is a relative newcomer to the genomics world, many secrets of the switchgrass genome have yet to be revealed. To continue to efficiently explore basic and applied topics in switchgrass, it will be critical to capture and exploit the knowledge of plant geneticists and breeders on the next logical steps in the development and utilization of genomic resources for this species. To this end, the community has established a switchgrass genomics executive committee and work group ( [verified 28 Oct. 2011])

Modern tests of Lorentz invariance

Motivated by ideas about quantum gravity, a tremendous amount of effort over the past decade has gone into testing Lorentz invariance in various regimes. This review summarizes both the theoretical frameworks for tests of Lorentz invariance and experimental advances that have made new high precision tests possible. The current constraints on Lorentz violating effects from both terrestrial experiments and astrophysical observations are presented.Comment: Modified and expanded discussions of various points. Numerous references added. Version matches that accepted by Living Reviews in Relativit

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

NEW FRICTION DURABLE ADDITIVE TECHNOLOGY AND ITS APPLICATION IN AUTOMATIC TRANSMISSIONS

Ovaj rad prikazuje razvoj tehnologije novih aditiva koja omogućuje formulaciju fluida za automatske prijenosnike (ATF-Automatic Transmission Fluids) na osnovi mineralnih ulja sa značajno poboljšanom otpornošću na trenje. U radu se uspoređuju performance trenja tehnologije novih aditiva kod komercijalno dostupnih ATF-a u Europi, Aziji i Sjevernoj Americi pri industrijski standardnim testovima trenja kao što su SAE No’2 rig (SAE No\u272 mjerna oprema) i Low Velocity Friction Apparatus (aparatura za ispitivanje trenja pri niskim brzinama). Isto tako, u radu se razmatraju primjeri još većih tehničkih izazova koje postavljaju posljednje ATF specifikacije u uvjetima još naglašenije oksidacije, trošenja, ekstremnih pritisaka, otpornosti na trenje, kapaciteta okretnog momenta i antikorozijskih zahtjeva, te se performance nove tehnologije aditiva otpornih na trenje uspoređuju s ostalim dostupnim ATF tehnologijama na nekim od spomenutih područja. Performance fluida otpornih na trenje koje su omogućene pomoću tehnologije novih aditiva mogu se primijeniti kod čitavog niza automatskih prijenosnika, npr. mokrih spojki za pokretanje, spojki pretvarača okretnog momenta, prijenosnika s dvostrukim spojkama i posljednje generacije automatskih prijenosnika sa šest, sedam, i osam stupnjeva prijenosa.This paper reports the development of a new additive technology allowing formulation of mineral oil based Automatic Transmission Fluids (ATFs) with significantly improved friction durability. The paper compares friction performance of the new additive technology with commercially available European, Asian and North American style ATFs in industry standard friction tests such as the SAE No’2 rig and the Low Velocity Friction Apparatus. The paper also considers examples of the broader technical challenges posed by the latest ATF specifications in terms of more stringent oxidation, wear, extreme pressure, friction durability, torque capacity and anti-corrosion requirements, and compares the performance of the new friction durable ATF technology with other commercially available ATFs in some of these areas. The fluid friction durability performance offered by this new additive technology is applicable in a variety of automatic transmission hardware, e.g. wet starting clutches, torque converter clutches, dual clutch transmissions and the latest generation six-, seven- and eight-speed step type automatic transmissions