Investigations of Emission Control Systems for Gasoline Direct Injection Engines with a Focus on Removal of Particulate Emissions

The removal of particulate emissions from gasoline injection engines is a new challenge within the exhaust aftertreatment system that will arise with the introduction of limits for particle number emitted by gasoline engines. Besides a possible adjustment of the engine management to lower the particulate emissions, catalyzed gasoline particulate filters (GPF) are conceivable as efficient pollution control devices. As an advantage, these catalyzed filters in addition could be able to support the conversion of all other regulated pollutants. Therefore, an emission study was carried out with systems consisting of a three-way catalyst and a catalyzed GPF and the impact of a dedicated washcoat on the filtration efficiency of the filter was analyzed. The conversion performance of the gasoline particulate filters was examined with regard to carbon monoxide, hydrocarbons and nitrous oxides emissions. Furthermore, the influence of the additional converter on fuel consumption and CO₂ emissions over different driving cycles will be discussed. In a detailed exhaust system study a correlation between the distance of engine-outlet to GPF-inlet and the filtration efficiency of the system was observed.     

Young children's imitation of sentence subjects: Evidence of processing limitations.

Elicited imitation was used to determine whether young children's inconsistent production of sentence subjects was due to limitations in their knowledge of English or in their ability to access and use that knowledge. Nineteen young children (age range = 1 year 10 months to 2 years 8 months; Mean Length of Utterance [MLU] range = 1.28 to 4.93) repeated sentences that varied in length, structure, and type of subject. A competence-deficit hypothesis would predict that children below MLU 3 would differentially omit expletive subjects and subjects preceded by a discourse topic more often than children above MLU 3. That hypothesis was disconfirmed. A performance-deficit hypothesis would predict that children below MLU 3 would omit more subjects from long sentences than short ones, and that the high-MLU children would not show a length effect. That hypothesis was confirmed. Processing limitations, rather than a defective grammar, explain very young children's absent subjects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hydrothermal Cement/Metal Interfaces

We investigated the adherence of two cementitious materials, calcium phosphate cement (CPC) and silica flour-filled class G cement (CGC), to metal substrates, such as cold-rolled steel (CRS), stainless steel (SS), electroplated zinc-coated steel (EZS), and zinc phosphate-coated steel (ZPS) after autoclaving at 200°C. In CPC/metal joints, the γ-AlOOH phase, which segregated from the hydroxyapatite phase of the CPC matrix, was preferentially precipitated on the CRS and SS surfaces and also mixed with the reaction products formed at the interfaces between CPC and EZS or ZPS. Precipitation of γ-AlOOH caused the formation of a weak boundary layer at the interfacial transition zones, thereby resulting in a low shear-bond strength. Although CGC accelerated the rate of corrosion of CRS and SS surfaces, the growth of Fe₂O₃ clusters, formed as the corrosion products of metals at interfaces, aided the anchoring effect of xonotlite crystals as the major phase of CGC matrix, thereby conferring a high shear-bond strength. The EZS and ZPS surfaces were susceptible to alkali dissolution caused by the attack of the high-pH interstitial fluid of CGC pastes to the Zn and zinc phosphate coatings. Thus, the bond strengths of the CGC/EZS and /ZPS joints were lower than those of the joints made with CRS and SS.     

The Role of Social Stressors and Interpersonal Orientation in Explaining the Longitudinal Relation Between Externalizing and Depressive Symptoms.

The authors examined the longitudinal association between externalizing and depressive symptoms using a sample of 185 young adolescents whose mothers had histories of depression. The relation between externalizing behaviors in 6th grade and depressive symptoms a year later was partially mediated by dependent social stressors. Moreover, consistent with the personality-event congruence hypothesis, this mediation model was particularly true for children with high levels of interpersonal orientation (Neediness and Connectedness). In contrast, social stressors that were judged to be independent of the children's behavior, as well as both dependent and independent nonsocial stressors, did not mediate the longitudinal relation between externalizing and depressive symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of mid‐ and near‐infrared techniques as tools for characterizing blends of copolymers of styrene–butadiene and acrylonitrile–butadiene

There is increased technological interest in using blends of various dissimilar elastomers in applications for which service, material availability, or cost of a single elastomer do not provide the necessary processing, vulcanizate, or economic properties. The properties of these polyblends are sensitive to small variations in the amounts of the individual polymers used. Accurately estimating the elastomer composition of blends is of vital importance to the elastomer industry. This study illustrates the feasibility of using mid-infrared (MIR) and near-infrared (NIR) spectroscopy to estimate the amount of styrene–butadiene and acrylonitrile–butadiene copolymers in blends composed of varying ratios of the two elastomers. Sometimes it is difficult to obtain a film of an elastomer amenable to IR analysis; to address this problem, several techniques were developed in this study [MIR transmission of a film, attenuated total internal reflection (ATR)-FTIR of a chunk, and NIR using a fiber-optic probe]. A plot of the absorbance ratio (absorbance of the characteristic peak for styrene–butadiene rubber or acrylonitrile–butadiene rubber/absorbance of the CC stretching vibration of polybutadiene) versus the amount of each elastomer in the blend was used to predict the blend composition. In addition, the blends were also characterized by ATR-FTIR using a plot of the characteristic peak absorbance versus the polymeric content for a series of standards. A partial least-squares algorithm was used to develop a calibration curve for the NIR region. Finally, the accuracy of the test methods developed in this work is compared to results obtained by pyrolysis-GC/MS and thermogravimetric analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88:1653–1658, 2003     

Masked repetition priming and proportion effects under cognitive load.

The authors used a cognitive load manipulation (rehearsing a string of digits during the trial) to test the automaticity of (a) masked repetition priming and (b) the masked repetition proportion (RP) effect (i.e., greater priming when the proportion of repetition-prime trials is higher) in the lexical decision task. The RP (.2 vs. .8) was varied across blocks. Masked priming was not reduced under load compared with a no-load group. Surprisingly, only the load group showed an RP effect in response latencies, although the no-load group showed an RP effect in the error rates. Our results show that masked priming is automatic, yet the influence of masked primes can nonetheless be adjusted at an unconscious level. Implications for accounts of masked priming are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dysfunctional beliefs and attitudes about sleep among older adults with and without insomnia complaints.

Examined the beliefs and attitudes about sleep among 145 older adults. Ss were either chronic insomniacs (n?=?74) or self-defined good sleepers (n?=?71). They rated their level of agreement or disagreement (visual analog scale) with 28 statements tapping various beliefs, expectations, and attributions about several sleep-related themes. The results showed that insomniacs endorsed stronger beliefs about the negative consequences of insomnia, expressed more hopelessness about the fear of losing control of their sleep, and more helplessness about its unpredictability. Findings suggest that some beliefs and attitudes about sleep may be instrumental in perpetuating insomnia. The main clinical implication is that these cognitions should be identified and targeted for alteration in the management of late-life insomnia. (PsycINFO Database Record (c) 2011 APA, all rights reserved)