20,710 research outputs found
SI Engine Simulation Using Residual Gas and Neural Network Modeling to Virtually Estimate the Fuel Composition
Research in electronic controlled internal
combustion engines mainly focuses on improving performance
and lowering the emissions. Combustion performance depends
on the geometry of cylinders and on the design of all
mechanical parts, which are based on the laboratory
experimental research. Due to the limitations of the materials
used in the engine and the continuous high operating
temperature, engines function in either spark ignition or
charge ignition processes. Recent research on computer
controlled engines uses sensors and electronic actuators which
allows switching the engine operational mode between spark
ignition and charge ignition. Thus, this makes possible to mix
intake fuel compositions in order to give more choices to
consumers.
This study employs a neural network which is capable of
estimating fuel composition using the parameters of residual
gas. The simulation is based on a thermodynamic engine model
implemented in Matlab Simulink. The main advantages are the
capabilities of the model to 1) calculate the gas exchange as a
function of time in transient mode, and 2) to generate data for
the design control algorithms without the need of the engine
bed test environment to test various fuel compositions
Anti-beta2 glycoprotein I (beta2GPI) antibodies facilitates phagocytosis of apoptotic neutrophils in patients with systemic lupus erythematosus (SLE)
BACKGROUND : Increased apoptosis provides a continuous source autoantigens and has been suggested to have a pathogenic role in SLE. We have previously shown patients with SLE have impaired clearance of apoptotic bodies. In this study, we evaluated whether anti-beta2GPI antibodies, a subset of antiphospholipid antibodies, may have an effect on the phagocytosis of apoptotic bodies by macrophages in these patients …published_or_final_versio
Study of the thermal stress in a Pb-free half-bump solder joint under current stressing
The thermal stress in a Sn3.5Ag1Cu half-bump solder joint under a 3.82×108 A/m2 current stressing was analyzed using a coupled-field simulation. Substantial thermal stress accumulated around the Al-to-solder interface, especially in the Ni+(Ni,Cu)3Sn4 layer, where a maximal stress of 138 MPa was identified. The stress gradient in the Ni layer was about 1.67×1013 Pa/m, resulting in a stress migration force of 1.82×10-16 N, which is comparable to the electromigration force, 2.82×10-16 N. Dissolution of the Ni+(Ni,Cu)3Sn4 layer, void formation with cracks at the anode side, and extrusions at the cathode side were observe
Joint Blind Motion Deblurring and Depth Estimation of Light Field
Removing camera motion blur from a single light field is a challenging task
since it is highly ill-posed inverse problem. The problem becomes even worse
when blur kernel varies spatially due to scene depth variation and high-order
camera motion. In this paper, we propose a novel algorithm to estimate all blur
model variables jointly, including latent sub-aperture image, camera motion,
and scene depth from the blurred 4D light field. Exploiting multi-view nature
of a light field relieves the inverse property of the optimization by utilizing
strong depth cues and multi-view blur observation. The proposed joint
estimation achieves high quality light field deblurring and depth estimation
simultaneously under arbitrary 6-DOF camera motion and unconstrained scene
depth. Intensive experiment on real and synthetic blurred light field confirms
that the proposed algorithm outperforms the state-of-the-art light field
deblurring and depth estimation methods
Divide-and-Conquer Monte Carlo Fusion
Combining several (sample approximations of) distributions, which we term
sub-posteriors, into a single distribution proportional to their product, is a
common challenge. For instance, in distributed `big data' problems, or when
working under multi-party privacy constraints. Many existing approaches resort
to approximating the individual sub-posteriors for practical necessity, then
representing the resulting approximate posterior. The quality of the posterior
approximation for these approaches is poor when the sub-posteriors fall
out-with a narrow range of distributional form. Recently, a Fusion approach has
been proposed which finds a direct and exact Monte Carlo approximation of the
posterior (as opposed to the sub-posteriors), circumventing the drawbacks of
approximate approaches. Unfortunately, existing Fusion approaches have a number
of computational limitations, particularly when unifying a large number of
sub-posteriors. In this paper, we generalise the theory underpinning existing
Fusion approaches, and embed the resulting methodology within a recursive
divide-and-conquer sequential Monte Carlo paradigm. This ultimately leads to a
competitive Fusion approach, which is robust to increasing numbers of
sub-posteriors.Comment: 24 pages, 8 figure
The Immunopathology of Sepsis: Pathogen Recognition, Systemic Inflammation, the Compensatory Anti-Inflammatory Response, and Regulatory T Cells
Questioning the source of identified non-foodborne pathogens from food-contact wooden surfaces used in Hong Kong's urban wet markets
In this study, a phylogenic analysis was performed on pathogens previously identified in Hong Kong wet markets' cutting boards. Phylogenetic comparisons were made between phylotypes obtained in this study and environmental and clinical phylotypes for establishing the possible origin of selected bacterial species isolated from wet market cutting board ecosystems. The results reveal a strong relationship between wet market bacterial assemblages and environmental and clinically relevant phylotypes. However, our poor knowledge of potential cross-contamination sources within these wet markets is further exacerbated by failing to determine the exact or presumed origin of its identified pathogens. In this study, several clinically relevant bacterial pathogens such as Klebsiella pneumoniae, Streptococcus suis and Streptococcus porcinus were linked to cutting boards associated with pork; Campylobacter fetus, Staphylococcus aureus, Escherichia coli, and A. caviae in those associated with poultry; and Streptococcus varanii, A. caviae, Vibrio fluvialis, and Vibrio parahaemolyticus in those associated with seafood. Identifying non-foodborne clinically relevant pathogens in wet market cutting boards in this study confirms the need for safety approaches for wet market meat, including cold storage. The presented study justifies the need for future systematic epidemiological studies to determine identified microbial pathogens. Such studies should bring about significant improvements in the management of hygienic practices in Hong Kong's wet markets and work towards a One Health goal by recognizing the importance of wet markets as areas interconnecting food processing with animal and clinical environments
Impacts of wet market modernization levels and hygiene practices on the microbiome and microbial safety of wooden cutting boards in Hong Kong
Accessing food through wet markets is a common global daily occurrence, where fresh meat can be purchased to support an urbanizing world population. Similar to the wet markets in many other metropolitan cities in Asia, Hong Kong wet markets vary and are characterized by differing hygiene routines and access to essential modern technologies. The lack of risk assessments of food contact surfaces in these markets has led to substantial gaps in food safety knowledge and information that could help improve and maintain public health. Microbial profiling analyses were conducted on cutting boards that had been used to process pork, poultry, and seafood at 11 different wet markets. The markets differed in hygiene protocols and access to modern facilities. Irrespective of whether wet markets have access of modern infrastructure, the hygiene practices were largely found to be inefficient based on the prevalence of bacterial species typically associated with foodborne pathogens such as Campylobacter fetus, Clostridium perfringens, Staphylococcus aureus, and Vibrio parahaemolyticus; indicator organisms such as Escherichia coli; as well as nonfoodborne pathogenic bacterial species potentially associated with nosocomial infections, such as Klebsiella pneumoniae and Enterobacter cloacae. Other Vibrio species, V. parahaemolyticus and V. vulnificus, typically associated with contaminated raw or undercooked seafood with the potential to cause illness in humans, were also found on wooden cutting boards. This study indicated that the hygienic practices used in Hong Kong wet markets are not sufficient for preventing the establishment of spoilage or pathogenic organisms. This study serves as a basis to review current hygiene practices in wet markets and provides a framework to reassess existing safety protocols
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