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Effects of Post-Injections Strategies on UHC and CO at Gasoline PPC Conditions in a Heavy-Duty Optical Engine

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

Control-Oriented Modeling of Soot Emissions in Gasoline Partially Premixed Combustion with Pilot Injection

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

Experimental investigations of potassium chemistry in premixed flames

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

Partial drying accelerates bacterial growth recovery to rewetting

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

NNT reverse mode of operation mediates glucose control of mitochondrial NADPH and glutathione redox state in mouse pancreatic β-cells

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

Sulfatase modifying factor 1 (SUMF1) is associated with Chronic Obstructive Pulmonary Disease

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

Using community trait-distributions to assign microbial responses to pH changes and Cd in forest soils treated with wood ash

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,

Perspectives for the Brazilian bioethanol sector : The innovation driver

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

The change of longitudinal relaxation rate in oxygen enhanced pulmonary MRI depends on age and BMI but not diffusing capacity of carbon monoxide in healthy never-smokers

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

See and tell : Differences between expert and novice teachers’ interpretations of problematic classroom management events

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.

Scrutinizing the relationship between adaptation and resilience : Longitudinal comparative case studies across shocks in two Nepalese villages

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

New contact allergens are formed during vulcanization of rubber

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

Screening of some European medicinal plants for spasmolytic activity on isolated guinea-pig trachea

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

On the use of coprostanol to identify source of nitrate pollution in groundwater

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 Imaging of Alkali Compounds in Flames

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

Utan stöd utifrån är den fred som var så nära plötsligt mycket långt borta igen.

Oavsett vilket scenario det blir ställer söndagens folkomröstning många saker på sin spets. En viktig fråga är om en fredlig samlevnad överhuvudtaget är möjligt i ett land där drygt hälften av befolkningen inte är redo att försonas. En annan aspekt är hur det internationella samfundet agerar. Hittills har det stött fredsprocessen såväl genom medling som ekonomiskt. Bland annat har Sverige erbjudit