The effect of oxygen and volatile combustibles on the sulphation of gaseous KCl

Sulphur/sulphate containing additives, such as elemental sulphur (S) and ammonium sulphate (NH4)(2)SO4), can be used for sulphation of KCl during biomass combustion. These additives convert KCl to an alkali sulphate and a more efficient sulphation is normally achieved for ammonium sulphate compared to sulphur. The presence of SO3 is thus of greater importance than that of SO2. Oxygen and volatile combustibles could also have an effect on the sulphation of gaseous KCl. This paper is based on results obtained during co-combustion of wood chips and straw pellets in a 12 MW circulating fluidised bed (CFB) boiler. Ammonium sulphate was injected at three positions in the boiler i.e. in the upper part of the combustion chamber, in the cyclone inlet, and in the cyclone. The sulphation of KCl was investigated at three air excess ratios (lambda = 1.1, 1.2 and 1.4). Several measurement tools were applied including IACM (on-line measurements of gaseous alkali chlorides), deposit probes (chemical composition in deposits collected) and gas analysis. The position for injection of ammonium sulphate had a great impact on the sulphation efficiency for gaseous KCl at the different air excess ratios. There was also an effect of oxygen on the sulphation efficiency when injecting ammonium sulphate in the cyclone. Less gaseous KCl was reduced during air excess ratio lambda = 1.1 compared to the higher air excess ratios. The optimal position and conditions for injection of ammonium sulphate were identified by measuring KCl with IACM. A correlation was observed between the sulphation of gaseous KCl and reduced chlorine content in the deposits. The experimental observations were evaluated using a detailed reaction mechanism. It was used to model the effect of volatile combustibles on the sulphation of gaseous MCI by SO3. The calculations supported the proposition that the presence of combustibles at the position of SO3 injection (i.e. AS) causes reduction of SO3 to SO2

Counteracting Forces in Implementation of IS-Enabled Global Business Processes

Many companies consider and undertake outsourcing of their software-development activities. Often information systems development is outsourced to vendors in different cultures or with a different level of software-process maturity. Recommendations for managing such outsourcing arrangements typically involve that client and vendor should increase interaction, learn more about the culture of the other part, communicate more, form partnerships, and the like. We have studied a client that did the opposite with a successful outcome. Based on a case study we lay out the story of how interaction between client and vendor on purpose was minimized. What mechanisms were used? What worked and what did not? We conclude that minimizing interaction can be a viable strategy to follow when clients face large cultural and maturity inequality in offshoring their software-development activities

The Day You Gave Us, Lord, Is Ended: SATB Choir

6 pages

On the Potential of Sequential and Nonsequential Regression Models for Sentinel-1-Based Biomass Prediction in Tanzanian Miombo Forests

This study derives regression models for aboveground biomass (AGB) estimation in miombo woodlands of Tanzania that utilize the high availability and low cost of Sentinel-1 data. The limited forest canopy penetration of C-band SAR sensors along with the sparseness of available ground truth restricts their usefulness in traditional AGB regression models. Therefore, we propose to use AGB predictions based on airborne laser scanning (ALS) data as a surrogate response variable for SAR data. This dramatically increases the available training data and opens for flexible regression models that capture fine-scale AGB dynamics. This becomes a sequential modeling approach, where the first regression stage has linked in situ data to ALS data and produced the AGB prediction map; we perform the subsequent stage, where this map is related to Sentinel-1 data.We develop a traditional, parametric regression model and alternative nonparametric models for this stage. The latter uses a conditional generative adversarial network (cGAN) to translate Sentinel-1 images into ALS-based AGB prediction maps. The convolution filters in the neural networks make them contextual. We compare the sequential models to traditional, nonsequential regression models, all trained on limited AGB ground reference data. Results show that our newly proposed nonsequential Sentinel-1-based regression model performs better quantitatively than the sequential models, but achieves less sensitivity to fine-scale AGB dynamics. The contextual cGAN-based sequential models best reproduce the distribution of ALS-based AGB predictions. They also reach a lower RMSE against in situ AGB data than the parametric sequential model, indicating a potential for further development

ADHD in girls and boys – gender differences in co-existing symptoms and executive function measures

Background: ADHD is diagnosed and treated more often in males than in females. Research on gender differences suggests that girls may be consistently underidentified and underdiagnosed because of differences in the expression of the disorder among boys and girls. One aim of the present study was to assess in a clinical sample of medication naïve boys and girls with ADHD, whether there were significant gender x diagnosis interactions in co-existing symptom severity and executive function (EF) impairment. The second aim was to delineate specific symptom ratings and measures of EF that were most important in distinguishing ADHD from healthy controls (HC) of the same gender. Methods: Thirty-seven females with ADHD, 43 males with ADHD, 18 HC females and 32 HC males between 8 and 17 years were included. Co-existing symptoms were assessed with self-report scales and parent ratings. EF was assessed with parent ratings of executive skills in everyday situations (BRIEF), and neuropsychological tests. The three measurement domains (co-existing symptoms, BRIEF, neuropsychological EF tests) were investigated using analysis of variance (ANOVA) and random forest classification. Results: ANOVAs revealed only one significant diagnosis x gender interaction, with higher rates of self-reported anxiety symptoms in females with ADHD. Random forest classification indicated that co-existing symptom ratings was substantially better in distinguishing subjects with ADHD from HC in females (93% accuracy) than in males (86% accuracy). The most important distinguishing variable was self-reported anxiety in females, and parent ratings of rule breaking in males. Parent ratings of EF skills were better in distinguishing subjects with ADHD from HC in males (96% accuracy) than in females (92% accuracy). Neuropsychological EF tests had only a modest ability to categorize subjects as ADHD or HC in males (73% accuracy) and females (79% accuracy). Conclusions: Our findings emphasize the combination of self-report and parent rating scales for the identification of different comorbid symptom expression in boys and girls already diagnosed with ADHD. Self-report scales may increase awareness of internalizing problems particularly salient in females with ADHD

Attention-deficit/hyperactivity disorder persistence from childhood into young adult age: a 10-year longitudinal study

Problems with executive function (EF) are considered a hallmark of Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). However, little is known about the developmental pathway of everyday EF in these two groups, and whether the two groups follow a similar or different developmental course. In this longitudinal study, children and adolescents with ADHD (n = 84, Mage = 11.6, SD = 2.0), ASD (n = 38, Mage = 12.0, SD = 2.3), and typically developing children (TDC; n = 50, Mage = 11.6, SD = 2.0) were clinically diagnosed and assessed with parent-ratings of everyday EF at baseline and at two-year followup (97% retention). Results showed that both individuals with ADHD and individuals with ASD displayed elevated levels of everyday EF problems relative to the TDC at baseline (Hedges g = 1.99 to 2.99). Over the two-year period, everyday EF improved in individuals with ADHD relative to the TDC, whereas individuals with ASD displayed no improvement relative to the TDC. At two-year followup, individuals with ADHD and individuals with ASD continued to display elevated levels of everyday EF problems relative to the TDC (Hedges g = 1.61 to 3.19).submittedVersio

Adolescence internalizing problems as a mediator between autism diagnosis in childhood and quality of life in emerging adults with and without autism: a 10-year longitudinal study

© The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License.Background Individuals with autism tend to have a reduced quality of life across their lifespan. This reduced quality of life may be a result of autism traits, mental distress, and poor person/environment fit. In this longitudinal study, we looked at the role of adolescence internalizing and externalizing problems in mediating the relationship between having an autism diagnosis from childhood and perceived quality of life as emerging adults.Methods A total of 66 participants in a group of emerging adults with autism (mean age 22.2 years), and without autism (mean age 20.9 years) were assessed in three assessment waves (T1 at 12 years, T2 at 14 years, and T3 at 22 years of age). Parents filled out the Child Behavior Checklist at T2 and participants filled out the Perceived Quality of Life Questionnaire at T3. Total and indirect effects were tested in serial mediation analysis.Results The results showed that internalizing problems fully mediated the association between childhood autism diagnosis and the quality of life in emerging adulthood, while externalizing problems did not.Conclusion Our findings suggest that attention to adolescent internalizing problems is important to improve the later quality of life for emerging adults with autism.publishedVersio