Comparison of accelerated anaerobic granulation obtained with a bench-scale rotating bioreactor vs. a stationary container for three different substrates

Anaerobic digestion is a very efficient technology for the treatment of wastewater from the food industries. The upflow sludge blanket reactor (UASB) is used to convert carbon in waste streams to CO2 and CH4. The risk of a shortage of anaerobic granules in a situation that requires a replacement granule charge for the UASB is a barrier to implementation of anaerobic technology in countries without UASB reactors, producing a surplus of granules to provide for an adequate inventory of granules. Accelerated granulation provides a means to reduce this risk. Peach cannery effluent (PCE), sucrose and lactate were tested as possible substrates for accelerated granulation inducement for un-granulated sewage sludge. Six experimental runs of 20 d each were done to explore granule growth. Each substrate was seeded with sewage sludge in a 5.4 ℓ bioreactor rotating at 2 r/min, as well as in a stationary container. A rapid drop in pH occurred during the first few days of every run. A lower overall pH in the bioreactor indicates a higher bacterial activity relative to the stationary container. The big drop in pH initially with PCE and sucrose inhibited methanogenic activity and granule growth for these substrates. The settleability of the final effluent from the reactor is superior to that of the stationary container. The total suspended solids analysis showed that the reactor produced a marked increase in the larger particulate sizes, indicating the positive contribution of the rolling action towards growth of granules.Keywords: anaerobic digestion, granulation, wastewater, accelerated granulatio

Investigating the impact of a combined approach of perceived organisational support for strengths use and deficit correction on employee outcomes

Orientation: The positive psychology paradigm suggests a balanced focus on employee strengths and deficits. However, an overemphasis on strengths has raised questions regarding the value of a focus on strengths use, deficit improvement or a combined approach with a balanced focus on both. Research purpose: The primary objective was to examine whether perceived organisational support (POS) for strengths use, POS for deficit improvement or a combined approach would be the strongest predictor of work engagement, learning, job satisfaction and turnover intention. Motivation for the study: In the literature, there is little empirical evidence to support an approach where both employees’ strengths are used and their deficits improved. Research design, approach and method: This study was conducted among 266 teachers from four public schools in the Western Cape. A cross-sectional survey design was used. Main findings: The results suggest that both strengths use and deficit improvement are important predictors of work engagement, learning, job satisfaction and turnover intention. Learning was higher and turnover intention lower for individuals experiencing a combined approach compared to those believing that their school did not support them in either using their strengths or improving their deficits. Furthermore, a combined approach was associated with higher job satisfaction than a strengths-based approach, and a deficit-based approach was shown to be associated with higher levels of work engagement and lower turnover intentions compared to an environment where neither employees’ strengths nor deficits were addressed. Practical or managerial implications: The results urge organisations to invest an equal amount of resources in their employees’ strengths and deficits, as opposed to neglecting either one. Such a combined approach may be associated with increased work engagement, learning and job satisfaction and lower turnover intention. Contribution: This study provides empirical evidence that supports a combined approach where both employees’ strengths are used and their deficits developed

Patients' experiences of transitioning between different renal replacement therapy modalities : a qualitative study

BACKGROUND: Different kidney replacement therapy modalities are available to manage end-stage kidney disease, such as home-based dialysis, in-center hemodialysis, and kidney transplantation. Although transitioning between modalities is common, data on how patients experience these transitions are scarce. This study explores patients' perspectives of transitioning from a home-based to an in-center modality. METHODS: Patients transitioning from peritoneal dialysis to in-center hemodialysis were purposively selected. Semi-structured interviews were performed, digitally recorded, and transcribed verbatim. Data analysis, consistent with Charmaz' constructivist approach of grounded theory was performed. RESULTS: Fifteen patients (10 males; mean age 62 years) participated. The conditions of the transitioning process impacted the participants' experiences, resulting in divergent experiences and associated emotions. Some participants experienced a loss of control due to the therapy-related changes. Some felt tied down and having lost independence, whereas others stated they regained control as they felt relieved from responsibility. This paradox of control was related to the patient having or not having (1) experienced a fit of hemodialysis with their personal lifestyle, (2) a frame of reference, (3) higher care requirements, (4) insight into the underlying reasons for transitioning, and (5) trust in the healthcare providers. CONCLUSIONS: Care teams need to offer opportunities to elicit patients' knowledge and fears, dispel myths, forge connections with other patients, and visit the dialysis unit before transition to alleviate anxiety. Interventions that facilitate a sense of control should be grounded in the meaning that the disorder has for the person and how it impacts their sense of self

Detailed abundance study of four s-process enriched post-AGB stars in the Large Magellanic Cloud

Context. The photospheric abundances of evolved solar-type stars of different metallicities serve as probes into stellar evolution theory. Aims. Stellar photospheres of post-asymptotic giant branch (post-AGB) stars bear witness to the internal chemical e

Impairment in preattentive visual processing in patients with Parkinson's disease

We explored the possibility of whether preattentive visual processing is impaired in Parkinson's disease. With this aim, visual discrimination thresholds for orientation texture stimuli were determined in two separate measurement sessions in 16 patients with idiopathic Parkinson's disease. The results were compared with those of 16 control subjects age-matched and 16 young healthy volunteers. Discrimination thresholds were measured in a four-alternative spatial forced-choice paradigm, in which subjects judged the location of a target embedded in a background of distractors. Four different stimulus configurations were employed: (i) a group of vertical targets among horizontal distractors (`vertical line targets'); (ii) targets with varying levels of orientation difference on a background of spatially filtered vertically oriented noise (`Gaussian filtered noise'); (iii) one `L' among 43 `+' signs (`texton'), all of which assess preattentive visual processing; and (iv) control condition, of one `L' among 43 `T' distractors (`non-texton' search target), which reflects attentive visual processing. In two of the preattentive tasks (filtered noise and texton), patients with Parkinson's disease required significantly greater orientation differences and longer stimulus durations, respectively. In contrast, their performance in the vertical line target and non-texton search target was comparable to that of the matched control subjects. These differences were more pronounced in the first compared with the second session. Duration of illness and age within the patient group correlated significantly with test performance. In all conditions tested, the young control subjects performed significantly better than the more elderly control group, further indicating an effect of age on this form of visual processing. The results suggest that, in addition to the well documented impairment in retinal processing, idiopathic Parkinson's disease is associated with a deficit in preattentive cortical visual processing