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Low temperature combustion modes, such as Homogeneous Charge Compression Ignition (HCCI) and Partially Premixed Combustion (PPC), have been researched over recent decades since the concepts show promise for high efficiency and low emissions compared to conventional diesel combustion. PPC is an intermediate combustion type ranging from HCCI-like combustion to diesel-like combustion. The purpose of
Gasoline partially premixed combustion (PPC) has shown potential in terms of high efficiency with low emissions of oxides of nitrogen (NOx) and soot. Despite these benefits, emissions of unburned hydrocarbons (UHC) and carbon monoxide (CO) are the main shortcomings of the concept. These are caused, among other things, by overlean zones near the injector tip and injector dribble. Previous diesel lo
In this paper, a control-oriented soot model was developed for real-time soot prediction and combustion condition optimization in a gasoline Partially Premixed Combustion (PPC) Engine. PPC is a promising combustion concept that achieves high efficiency, low soot and NOx emissions simultaneously. However, soot emissions were found to be significantly increased with high EGR and pilot injection, the
Quantitative potassium species concentrations have been measured in alkali-seeded premixed methane-air flames of different stoichiometry. Potassium chloride (KCl) and hydroxide (KOH) were measured by broadband UV absorption spectroscopy and laser-induced photofragmentation fluorescence, while atomic potassium was measured using tuneable diode-laser spectroscopy. In addition, laser Rayleigh scatter
Fluctuations in soil moisture create drying-rewetting events affecting the activity of microorganisms. Microbial responses to drying-rewetting are mostly studied in soils that are air-dried before rewetting. Upon rewetting, two patterns of bacterial growth have been observed. In the Type 1 pattern, bacterial growth rates increase immediately in a linear fashion. In the Type 2 pattern, bacterial gr
Objective: The glucose stimulation of insulin secretion (GSIS) by pancreatic β-cells critically depends on increased production of metabolic coupling factors, including NADPH. Nicotinamide nucleotide transhydrogenase (NNT) typically produces NADPH at the expense of NADH and δpH in energized mitochondria. Its spontaneous inactivation in C57BL/6J mice was previously shown to alter ATP production, Ca
Background: It has been observed that mice lacking the sulfatase modifying factor (Sumf1) developed an emphysema-like phenotype. However, it is unknown if SUMF1 may play a role in Chronic Obstructive Pulmonary Disease (COPD) in humans. The aim was to investigate if the expression and genetic regulation of SUMF1 differs between smokers with and without COPD. Methods: SUMF1 mRNA was investigated in
The identification of causal links between microbial community structure and ecosystem functions are required for a mechanistic understanding of ecosystem responses to environmental change. One of the most influential factors affecting plants and microbial communities in soil in managed ecosystems is the current land-use. In forestry, wood ash has been proposed as a liming agent and a fertilizer,
This article addresses the future of Brazil's bioethanol sector, focusing on its capabilities to innovate, its efforts toward producing cellulosic ethanol, and on recently implemented policies. Contrary to what has been argued in the literature, Brazil may not be prepared to face the technological and market challenges now emerging in the biofuels domain worldwide. Important productive investments
Objective: Oxygen enhanced pulmonary MRI is a promising modality for functional lung studies and has been applied to a wide range of pulmonary conditions. The purpose of this study was to characterize the oxygen enhancement effect in the lungs of healthy, never-smokers, in light of a previously established relationship between oxygen enhancement and diffusing capacity of carbon monoxide in the lun
Experience in the classroom influences how teachers interpret classroom events. This article investigated differences between expert and novice teachers' interpretations of authentic, problematic classroom events. Two types of videos presented problematic events, displaying either unrelated problems, such as disengaged, off-task students, or interrelated problems leading to a flagrant disruption.
Growing concerns regarding the vulnerability of communities to natural disasters and climate-related hazards and risks have caused attention to be increasingly directed towards adaptation and resilience as important policy prescriptions. These two concepts are commonly becoming normative when used in this context and seen as intrinsically linked to each other, i.e. adaptation leads to resilience a
In rubber materials, both natural rubber and synthetic rubber, several different contact allergenic chemicals are added to the batch before vulcanization. These compounds are relevant for investigation of rubber allergy of workers in rubber factories. The number of workers in the rubber industry has declined, owing to increased automation of the process; however, the number of users of rubber prod
Eight European plants, used traditionally against diseases of the respiratory system, have been assayed for in vitro spasmolytic activity on guinea-pig trachea. The plants were collected or cultivated in the south of Sweden, and both water and 67% methanol extracts of the parts reported to be used in the traditional medicine were prepared and assayed. Five of the species did not show any significa
Investigation of contaminant sources is indispensable for developing effective countermeasures against nitrate (NO3 −) pollution in groundwater. Known major nitrogen (N) sources are chemical fertilizers, livestock waste, and domestic wastewater. In general, scatter diagrams of δ18O and δ15N from NO3 − can be used to identify these pollution sources. However, this method can be difficult to use for
Laser-induced photofragmentation fluorescence has been investigated for the imaging of alkali compounds in premixed laminar methane–air flames. An ArF excimer laser, providing pulses of wavelength 193 nm, was used to photodissociate KCl, KOH, and NaCl molecules in the post-flame region and fluorescence from the excited atomic alkali fragment was detected. Fluorescence emission spectra showed disti
We prove sufficient and necessary conditions for the compactness of Calderón-Zygmund operators on the endpoint from L∞ (R) into CMO(R). We use this result to prove the compactness on Lp (R) with 1 < p < ∞ of a certain perturbation of the Cauchy integral on curves with normal derivatives satisfying a CMO-condition.
