Synthesis of ZnO-based varistor precursor powders by means of the reaction spray process

High-purity, fine-grained oxide ceramic powders that are commonly used for ZnO-based varistors were synthesized by means of the reaction spray process. Processing steps included formation of the solutions of zinc nitrate and/or certain metal additives and spraying of the solution into a heated reaction column using a two-phase nozzle. After water evaporation from the droplets, the precursor salts were decomposed at elevated temperatures (up to 1473 K) in order to obtain homogeneous oxide powders with complex compositions corresponding to the final multicomponent varistor system. The decomposition behaviour of the precursors, as well as the characteristics of the resulting powders: crystallinity, phase composition, particle shape, morphology and particle-size distribution, were examined. It was shown that the characteristics of the reaction spray-derived powders can be controlled by adjusting the system and the solutions parameters.     

Use of flow-normalization to evaluate nutrient concentration and flux changes in Lake Champlain tributaries, 1990–2009

The U.S. Geological Survey evaluated 20 years of total phosphorus (P) and total nitrogen (N) concentration data for 18 Lake Champlain tributaries using a new statistical method based on weighted regressions to estimate daily concentration and flux histories based on discharge, season, and trend as explanatory variables. The use of all the streamflow discharge values for a given date in the record, in a process called “flow-normalization”, removed the year-to-year variation due to streamflow and generated a smooth time series from which trends were calculated. This approach to data analysis can be of great value to evaluations of the success of restoration efforts because it filters out the large random fluctuations in the flux that are due to the temporal variability in streamflow. Results for the full 20 years of record showed a mixture of upward and downward trends for concentrations and yields of P and N. When the record was broken into two 10-year periods, for many tributaries, the more recent period showed a reversal in N from upward to downward trends and a similar reversal or reduction in magnitude of upward trends for P. Some measures of P and N concentrations and yields appear to be related to intensity of agricultural activities, point-source loads of P, or population density. Total flow-normalized P flux aggregated from the monitored tributaries showed a decrease of 30 metric tons per year from 1991 to 2009, which is about 15% of the targeted reduction established by the operational management plan for the Lake Champlain Basin.     

Multi-product economic lot scheduling problem with manufacturing and remanufacturing using a basic period policy

In this research we study the multi-product Economic Lot Scheduling Problem (ELSP) with manufacturing and remanufacturing opportunities. Manufacturing and remanufacturing operations are performed on the same production line. Both manufactured and remanufactured products have the same quality thus they fulfil the same demand stream. Tang and Teunter (2006) firstly studied this type of Economic Lot Scheduling Problem with Returns (ELSPR) and presented a complex algorithm for the optimal solution. More recently Teunter, Tang, and Kaparis (2009) proposed several heuristics to deal with the same problem using more computational efficient approaches. However, both studies have limited the attention to the common cycle policy with the assumption that a single (re)manufacturing lot is used for each item in each cycle. Relaxing the constraint of common cycle time and a single (re)manufacturing lot for each item in each cycle, we propose a simple, easy to implement algorithm, based on Segerstedt (1999), to solve the model using a basic period policy. Several numerical examples show the applicability of the algorithm and the cost savings.     

A longitudinal study of emoticon use in text messaging from smartphones

Our goal in the present study was to understand how emoticons are used in text messaging and, in particular, how genders differed in the frequency and variety of emoticons used via this medium. Previous research has found small and sundry differences in emotive expression online suggesting that technology has closed the gender gap. However, the data collected in these studies were public. In this study, we collected real portions of private communications data from individuals’ smartphones over a 6-month period. SMS messages, in general, were not used very much overall, with only 4% of all messages containing at least one emoticon. Still, differences between genders manifested in the amount and variety of emoticons used. Females sent more messages with emoticons; however, surprisingly, males used a more diverse range of emoticons.     

On using planning poker for estimating user stories

While most studies in psychology and forecasting stress the possible hazards of group processes when predicting effort and schedule, agile software development methods recommend the use of a group estimation technique called planning poker for estimating the size of user stories and developing release and iteration plans. It is assumed that the group discussion through planning poker helps in identifying activities that individual estimators could overlook, thus providing more accurate estimates and reducing the over-optimism that is typical for expert judgment-based methods. In spite of the widespread use of agile methods, there is little empirical evidence regarding the accuracy of planning poker estimates. In order to fill this gap a study was conducted requiring 13 student teams to develop a Web-based student records information system. All teams were given the same set of user stories which had to be implemented in three Sprints. Each team estimated the stories using planning poker and the estimates provided by each team member during the first round were averaged to obtain the statistical combination for further comparison. In the same way the stories were estimated by a group of experts. The study revealed that students’ estimates were over-optimistic and that planning poker additionally increased the over-optimism. On the other hand, the experts’ estimates obtained through planning poker were much closer to actual effort spent and tended to be more accurate than the statistical combination of their individual estimates. The results indicate that the optimism bias caused by group discussion diminishes or even disappears as the expertise of the people involved in the group estimation process increases.     

Self-Organising Maps: A new way to screen the level of satisfaction of dialysis patients

Evaluation of patient satisfaction has become an important indicator for assessing health care quality. Fresenius Medical Care (FME) as a global provider of dialysis services through its NephroCare network has a strong interest in monitoring patient satisfaction.The aim of the paper is to test and validate a methodology for detecting a residual area of low satisfaction in dialysis patients.The FME Patient Satisfaction Programme questionnaire was distributed to haemodialysis (HD) patients treated in 335 centers of its network. It contained 79 questions covering various satisfaction aspects regarding Dialysis Unit, Dialysis Arrangement, Nurses, Doctors, etc.To analyse the data provided by the questionnaire, the Self-Organising Map (SOM) method was used. SOM is a neural network model for clustering and projecting high-dimensional data into a low-dimensional space, preserving topological relationships of original high-dimensional data spaces.10,632 HD patients completed the questionnaire. Mean age was 63.05 ± 14.93 years with 56.69% males. Response rate was 66%. Overall level of satisfaction was 1.99 (range from ?3 to +3). On average patients were very satisfied with all issues. Nevertheless, a group of patients, around 60 years old, balanced gender ratio, whose level of satisfaction was lower than 1, were highlighted.In the NephroCare clinics patient satisfaction with service is rather high. While traditional analysis usually stops here, the SOM method allows identification of areas of potential improvement for specific patient groups.     

Divergent trajectories in the aging mind: Changes in working memory for affective versus visual information with age.

Working memory mediates the short-term maintenance of information. Virtually all empirical research on working memory involves investigations of working memory for verbal and visual information. Whereas aging is typically associated with a deficit in working memory for these types of information, recent findings suggestive of relatively well-preserved long-term memory for emotional information in older adults raise questions about working memory for emotional material. This study examined age differences in working memory for emotional versus visual information. Findings demonstrate that, despite an age-related deficit for the latter, working memory for emotion was unimpaired. Further, older adults exhibited superior performance on positive relative to negative emotion trials, whereas their younger counterparts exhibited the opposite pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Telehealth Brain Injury Training for Rural Behavioral Health Generalists: Supporting and Enhancing Rural Service Delivery Networks.

Rural psychologists are frontline primary behavioral health care providers for nearly 60 million Americans, but they face limited access to peer consultation and continuing education. This article describes a program that matched 70 rehabilitation inpatients who had new brain injury with rural clinicians from patients' home communities. Neuropsychologists provided one-on-one training for clinicians through telehealth video teleconferencing. Clinicians showed gains in brain injury knowledge, and clients rated trained providers higher than untrained providers. Families seeking brain injury services can connect with these trained rural providers through a Web site, which receives more than 800 hits per month. Telehealth offers potential for rural clinicians to receive support, reduce professional isolation, gain working knowledge of specialty conditions, and deliver high-quality services for their rural clients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Socioeconomic Status, Resources, Psychological Experiences, and Emotional Responses: A Test of the Reserve Capacity Model.

The current study used ecological momentary assessment to test several tenets of the reserve capacity model (L.C. Gallo & K. A. Matthews, 2003). Women (N = 108) with varying socioeconomic status (SES) monitored positive and negative psychosocial experiences and emotions across 2 days. Measures of intrapsychic and social resources were aggregated to represent the reserve capacity available to manage stress. Lower SES was associated with less perceived control and positive affect and more social strain. Control and strain contributed to the association between SES and positive affect. Lower SES elicited greater positive but not negative emotional reactivity to psychosocial experiences. Women with low SES had fewer resources relative to those with higher SES, and resources contributed to the association between SES and daily experiences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Permutation routing in double-loop networks: design and empirical evaluation

A double-loop network is an undirected graph whose nodes are integers 0,1,…,n−1 and each node u is adjacent to four nodes u±h₁(mod>n), u±h₂(mod>n), where 0<h₁<h₂<n/2. There are initially n packets, one at each of the n nodes. The packet at node u is destined to node π(u), where the mapping uπ(u) is a permutation. The aim is to minimize the number of routing steps to route all the packets to their destinations. If ℓ is the tight lower bound for this number, then the best known permutation routing algorithm takes, on average, 1.98ℓ routing steps (and 2ℓ routing steps in the worst-case).Because the worst-case complexity cannot be improved, we design four new static permutation routing algorithms with gradually improved average-case performances, which are 1.37ℓ, 1.35ℓ, 1.18ℓ, and 1.12ℓ. Thus, the best of these algorithms exceeds the optimal routing by at most 12% on average.To support our algorithm design we develop a program which simulates permutation routing in a network according to the given topology, routing model as well as communication pattern and measure several quality criteria. We have tested our algorithms on a large number of double-loop networks and permutations (randomly generated and standard).