Environmental life-cycle inventory of detergent-grade surfactant sourcing and production

Life-cycle inventories were compiled to characterize natural resource requirements and environmental emissions associated with the sourcing and production of selected, detergent-grade surfactants and surfactant feedstocks. Petrochemical surfactant types examined were linear alkylbenzene sulfonate, alcohol sulfate (AS), alcohol ethoxylate (AE) and alcohol ethoxylate sulfate (AES). Oleochemical surfactants derived from palm oil, palm kernel oil and inedible tallow were AS, AE, AES and (for palm oil and tallow) methyl ester sulfonate. It was determined that natural resource requirements were primarily related to the source of feedstock and secondarily to surfactant type. Likewise, the composition and mass of atmospheric, aqueous and solid emissions were principally determined by feedstock source. Energy requirements varied as a function of both feedstock and surfactant type. The inventories do not support fundamental shifts in surfactant usage or feedstock sourcing on the basis of environmental concerns, as no single surfactant or feedstock was identified as superior across all resource and emissions criteria examined. The data provide baselines for evaluating opportunities for resource optimization, pollution prevention and waste minimization within each production technology surveyed.     

The influence of problem ownership on teachers' perceptions of and strategies for coping with problem students.

98 elementary school teachers read vignettes depicting incidents involving (fictional) students who presented chronic behavior problems and then told how they would respond if the incidents occurred in their classrooms. Responses were coded for attributions about the students and about the Ss' roles in causing and correcting the problems. Ss attributed controllability and intentionality to students presenting teacher-owned problems but not to students presenting student-owned problems. Students presenting shared problems often were seen as able to control their behavior but not as misbehaving intentionally. The contrasting patterns of attribution seen in these 3 levels of problem ownership were associated with contrasting patterns of goals and strategies, as well. The data bear out expectations based on attributional analyses of helping behavior but raise questions about teachers' preparedness to cope with problem students. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Energy and Mass Transfer Phenomena in Natural Draft Cooling Towers

In this paper, the development of natural draft cooling towers diagnostics is presented. Diagnostic method is based on measurements of velocity and temperature fields of the airflow in the entire surface area of cooling tower and the raised phenomenological model of heat and mass transfer in a selected reference vertical segment of cooling tower. Velocity and temperature fields of the airflow were measured with the aid of a remote control mobile robot unit that was developed to enable measurements in an arbitrary measurement point above the spray zones over the entire cooling tower area. Topological structures of the humid air velocity profiles and temperature profiles above the spray zones were obtained at constant integral parameters of a power plant. Measurement results of temperature and mass flow characteristics of the air and water flows in a selected reference vertical segment of cooling tower are presented in the form of phenomenological dependence. Phenomenological dependence links local cooling tower efficiency, geometrical characteristics of spray elements, and air and water flow rates. In the concluding part, both methods are applied together on a selected segment of cooling tower, and local and integral cooling tower efficiency can be determined.     

Efficient current reuse for low-power transceivers

Current boosting is a method where the performance of an active circuit block is optimized by placing a constant current source in parallel with the active signal path to provide optimal biasing for different components. In this paper, a technique to replace the constant dc current source with active building blocks typically required in transceivers is proposed. By using this method the total current consumption of the transceiver can be efficiently reduced without modifying its performance. A design example where the proposed technique reduces the receiver current consumption by 45% is given.     

Relationships between teachers' presentations of classroom tasks and students' engagement in those tasks.

Correlated the presence/absence of various teacher task-presentation statements with measures of subsequent student task engagement to investigate the possibility that expectations about classroom tasks that teachers communicate to students in the process of presenting those tasks might affect student engagement in the tasks. Reading and math lessons were observed (8–25 times each) in 2 4th-grade, 2 5th-grade, and 2 6th-grade classes. Typically, each reading or math period was subdivided into 2–4 tasks. For example, a math period might begin with a review of the previous day's seatwork/homework assignment, followed by presentation of a new concept or skill, followed by presentation of a new assignment. Teacher-presentation data and student-engagement data were collected for each task observed. Contrary to expectation, student engagement was generally higher when teachers moved directly into tasks than when they began with some presentation statement. Within the subset of tasks that were begun with teacher-presentation statements, those presentation statements classified as likely to have negative effects on student engagement were associated with lower student engagement, but there was no corresponding tendency for teacher-presentation statements classified as likely to have positive effects on student engagement to be associated with high rates of student engagement. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Research on the self-fulfilling prophecy and teacher expectations.

Reviews the literature on self-fulfilling prophecy and teacher expectations and concludes that a minority of teachers have major expectation effects on their students' achievement. However, such effects are minimal for most teachers because their expectations are generally accurate and open to corrective feedback. It is difficult to predict the effects of teachers' expectations, even with knowledge of their accuracy and the degree of rigidity with which they are held. Expectations interact with beliefs about learning and instruction to determine teacher behavior; similar expectations may lead to different behavior. Students will also differ in their interpretation of and response to teacher behavior; similar behavior may produce different student outcomes. (106 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Classroom observation scales: Stability across time and context and relationships with student learning gains.

Used 12 Classroom Observation Scales developed from prior factor-analytic work by E. Emmer and R. Peck (1973) in a process-product study of 165 2nd- and 3rd-grade teachers' success in producing student learning gains on the Metropolitan Achievement Tests. The scales, which measure general process variables stressed in previous classroom research, showed good stability across years and across contexts within years. However, they did not show the numbers and kinds of relationships with student learning gains expected on the basis of previous research. These unexpected findings are indicative of the effects of pupil characteristics and teaching-learning patterns unique to the early elementary grades which call for different teacher behaviors than those which appear to be optimal at higher grade levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Classroom dyadic interaction: Factor structure of process variables and achievement correlates.

Obtained data from 28 2nd- and 3rd-grade teachers who were consistent in obtaining student achievement gains on the Metropolitan Achievement Test. 21 dyadic interaction process variables obtained from the Texas Teacher Effectiveness Project Coding System were entered into factor analyses which showed more congruence between the factor structures of the whole-class contexts (morning and afternoon) than between those data subsets and reading group factors. Resulting factor scores were correlated with achievement criteria. Although significant correlations were few in number, the data suggest that in higher socioeconomic status classes, verbal praise was particularly ineffective; also, successful teachers in lower social status classrooms interacted privately with students (instead of during public discussions). Effective teachers in lower and higher social status classes placed an emphasis on fast-paced activities during reading groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Megaprojects as organizational platforms and technology platforms for value creation

Megaprojects are multi-actor and multi-technology constellations that create value for society. Previous research on joint and coordinated activities to create value for multiple actors in megaprojects over system lifecycle is scarce. This study explores how the actors in a megaproject jointly create value. We analyze value creation in megaprojects by theorizing on the research on organizational platforms, which draws together knowledge from research on other types of platforms, ecosystems and networks. In our empirical study, we analyze a city district renewal megaproject, by focusing on the actors' joint activities that contribute to synergetic project processes, solutions and outcomes both tangible and intangible that participating actors find beneficial. We derive five propositions that explain how actors in a megaproject create value through jointly planned and governed design principles, and through value-leveraging activities. Jointly planned and governed design principles include inter-organizational coordinating bodies and joint activities that share ownership and decision-making. In value-leveraging activities, leader actors facilitate megaproject actors' competition and value capture that determine most suitable participants to value-creating activities.