1,262 research outputs found
Investigations on Deposit Formation in the Holes of Diesel Injector Nozzles
Current developments in fuels and emissions regulations are resulting in an increasingly severe operating environment for diesel fuel injection systems. The formation of deposits within the holes or on the outside of the injector nozzle can affect the overall system performance. The rate of deposit formation is affected by a number of parameters, including operating conditions and fuel composition. For the work reported here an accelerated test procedure was developed to evaluate the relative importance of some of these parameters in a high pressure common rail fuel injection system. The resulting methodology produced measurable deposits in a custom made injector nozzle on a single cylinder engine. The results indicate that fuels containing 30%v/v and 100% Fatty Acid Methyl Ester (FAME), that does not meet EN 14214 produced more deposit than an EN590 petroleum diesel fuel. Overall, the addition of zinc to the fuel had the biggest effect on deposit formation and resulted in a 12.2% decrease in Indicated Mean Effective Pressure (IMEP). The effects of zinc were unexpectedly reduced when it was added to fuel containing 30%v/v biodiesel. Reducing the common-rail pressure with 30%v/v biodiesel (no added zinc) increased the loss in IMEP. Raising the air and fuel temperatures by 40°C and 30°C respectively showed no bigger loss in IMEP. The results indicate that deposit formation may continue after engine shut down. © 2011 Society of Automotive Engineers of Japan, Inc. and SAE International
Three-body correlations and finite-size effects in the Moore--Read states on a sphere
Two- and three-body correlations in partially filled degenerate fermion
shells are studied numerically for various interactions between the particles.
Three distinct correlation regimes are defined, depending on the short-range
behavior of the pair pseudopotential. For pseudopotentials similar to those of
electrons in the first excited Landau level, correlations at half-filling have
a simple three-body form consisting of the maximum avoidance of the triplet
state with the smallest relative angular momentum R_3=3. In analogy to the
superharmonic criterion for Laughlin two-body correlations, their occurrence is
related to the form of the three-body pseudopotential at short range. The
spectra of a model three-body repulsion are calculated, and the zero-energy
Moore--Read ground state, its +-e/4-charged quasiparticles, and the
magnetoroton and pair-breaking bands are all identified. The quasiparticles are
correctly described by a composite fermion model appropriate for Halperin's
p-type pairing with Laughlin correlations between the pairs. However, the
Moore--Read ground state, and specially its excitations, have small overlaps
with the corresponding Coulomb eigenstates when calculated on a sphere. The
reason lies in surface curvature which affects the form of pair pseudopotential
for which the "R_3>3" three-body correlations occur. In finite systems, such
pseudopotential must be slightly superharmonic at short range (different from
Coulomb pseudopotential). However, the connection with the three-body
pseudopotential is less size-dependent, suggesting that the Moore--Read state
and its excitations are a more accurate description for experimental nu=5/2
states than could be expected from previous calculations.Comment: 12 pages, 12 figures, submitted to PR
Microwave-Assisted Depolymerisation of Biolignintm in the Presence of Zeolite-Based Catalysts
In this work a microwave-assisted depolymerisation of lignin in the presence of zeolite-based catalysts was studied in order to obtain a valuable bio-oil. Catalytic activity of H-ZSM-5, H-Y, H-BETA and H-Mordenite containing nano-NiO particles was investigated in the depolymerisation of BioligninTM. The catalysts were prepared by mechanochemical dry milling (MCDM) method following by calcination under air at 400 °C. The highest bio-oil yield of 8.78 wt. %, was obtained in the presence of NiO-containing H-ZSM-5
Edge excitations and Topological orders in rotating Bose gases
The edge excitations and related topological orders of correlated states of a
fast rotating Bose gas are studied. Using exact diagonalization of small
systems, we compute the energies and number of edge excitations, as well as the
boson occupancy near the edge for various states. The chiral Luttinger-liquid
theory of Wen is found to be a good description of the edges of the bosonic
Laughlin and other states identified as members of the principal Jain sequence
for bosons. However, we find that in a harmonic trap the edge of the state
identified as the Moore-Read (Pfaffian) state shows a number of anomalies. An
experimental way of detecting these correlated states is also discussed.Comment: Results extended to larger systems. Improved presentatio
Cytotoxic effects of selected gold(III) complexes on the murine BCL-1 B lineage leukaemia cell line
In recent years, gold(III) complexes have attracted great interest because of their cytotoxicity to cancer cells. We investigated the cytotoxic effects of three newly synthesised gold(III) complexes, [Au(en)Cl 2] + (dichloride (ethylendiamine) aurate(III)-ion), [Au(dach)Cl 2] (dichloride (1,2- diaminocyclohexane) aurate(III)-ion) and [Au(bipy)Cl 2] + (dichloride (2,2'-bipyridyl) aurate(III)-ion), on the murine BCL-1 B lineage leukaemia cell line. The cytotoxicity of these gold(III) complexes was evaluated by cytotoxic assay (MTT test). The results showed that all of the tested gold(III) complexes displayed a cytotoxic effect on BCL-1 cells. The concentration decrease was followed by a marked increase in BCL-1 cell viability. At a concentration of 125 μM, which we suppose could be used in vivo, the [Au(bipy)Cl 2] + complex showed the greatest cytotoxic effects among the tested gold(III) complexes and similar cytotoxicity asto the cisplatinum that we used as control. Among the tested gold(III) complexes, [Au(en)Cl 2] +was the least cytotoxic to BCL-1 cells. In line with the obtained results, we suggest that the [Au(bipy)Cl 2] + complex should be tested in vivo in experimental models of B cell leukaemia
Remaining life of TI-6AL-4V ELI HIP IMPLANT WITH A CRACK
Fatigue failure is the main issue in design of hip implants. One way to prolong fatigue life is to use newly developed Ti6Al4V Extra Low Interstitials (ELI) alloy. As the most critical part, hip neck has been in the focus of this analysis, keeping in mind that the lower the thickness is, the higher the movement of joint may be, but reducing remaining life of implants with a crack at the same time. In this research extended Finite Element Method (xFEM) is used to analyse this effec
A cross-country examination on the fear of covid-19 and the sense of loneliness during the first wave of covid-19 outbreak
The aim of the current study is to examine gender, age. and cross-country differences in fear of COVID-19 and sense of loneliness during the lockdown, by comparing people from those countries with a high rate of infections and deaths (e.g., Spain and Italy) and from countries with a mild spread of infection (e.g., Croatia, Serbia, Slovakia, Slovenia, and Bosnia and Herzegovina). A total of 3876 participants (63% female) completed an online survey on “Everyday life practices in COVID-19 time” in April 2020, including measures of fear of COVID-19 and loneliness. Males and females of all age groups in countries suffering from the powerful impact of the COVID-19 pandemic reported greater fear of COVID-19 and sense of loneliness. In less endangered countries, females and the elderly reported more symptoms than males and the young; in Spanish and Italian samples, the pattern of differences is considerably more complex. Future research should thoroughly examine different age and gender groups. The analysis of emotional well-being in groups at risk of mental health issues may help to lessen the long term social and economic costs due to the COVID-19 outbreak
Differences in the Psychological Profiles of Elite and Non-elite Athletes
One of the main goals of sport psychology is to identify those psychological factors that are relevant for sport performance as well as possibilities of their development. The aim of the study was to determine whether the set of specific psychological characteristics [generalized self-efficacy, time perspective, emotional intelligence (EI), general achievement motivation, and personality dimensions] makes the distinction between athletes based on their (non)-participation in the senior national team, that is, their belonging to the subsample of elite or non-elite athletes depending on this criterion. According to the group centroids it can be said that elite athletes are characterized by a positive high score in self-efficacy, emotionality, present fatalistic time perspective, past positive time perspective, and openness to experience. They are also characterized by low past negative time perspective, emotional competence, and future time perspective. Non-elite athletes have the opposite traits. The results have been discussed in the context of their application in the process of talent selection and development in sport as well as the development of life skills in athletes
- …