Using macromolecular composition to predict optimal process settings in ring-die biomass pellet production

This study was performed to investigate if the process settings that give high pellet durability can be modelled from the biomass’ macromolecular composition. Process and chemical analysis data was obtained from a previous pilot-scale study of six biomass assortments that by Principal Component Analysis (PCA) was confirmed as representative for their biomass types: hardwood, softwood bark, short rotation coppice (SRC), and straw and energy crops. Orthogonal Partial Least Squares Projections to Latent Structures (OPLS) models were created with the content of macromolecules as factors and the die compression ratio and the feedstock moisture content at which the highest pellet durability was obtained as responses. The models for die compression ratio (R2X = 0.90 and Q2 = 0.58) and feedstock moisture content (R2X = 0.87 and Q2 = 0.60), rendered a prediction error for obtained mechanical durability of approximately ±1%-unit, each. Important factors for modelling of the die compression ratio were: soluble lignin (negative), acetyl groups (negative), acetone extractives (positive), and arabinan (positive). For modelling of the feedstock moisture content, Klason lignin (negative), xylan (positive), water-soluble extractives (negative), and mannan (negative), were the most influential. Results obtained in this study indicate that it is possible to predict optimal process conditions in pelletizing based on the macromolecular composition of the raw material. In practice, this would mean a higher raw material flexibility in the pellet factories through drastically reduced risk when introducing new raw materials

Estrés y desempeño laboral en trabajadores de una empresa privada de servicios de Lima, 2020

El objetivo general de la presente investigación fue determinar la relación que existe entre el estrés y desempeño laboral en trabajadores de una empresa privada de servicios de Lima, 2020. La muestra estuvo conformada por 151 colaboradores de ambos sexos. Los instrumentos empleados fueron la Escala de Estrés Laboral de la OIT – OMS y el Cuestionario de desempeño laboral de Montoya. Los resultados indicaron que existe una relación estadísticamente significativa, inversa y débil entre las variables estrés y desempeño laboral. En cuanto a la variable estrés laboral se encontró un nivel medio y en la variable desempeño laboral se encontró un nivel alto

Pelleting torrefied biomass at pilot-scale – Quality and implications for co-firing

The co-firing of solid biofuels in coal plants is an attractive and fast-track means of cutting emissions but its potential is linked to biomass densification. For torrefied materials this topic is under-represented in literature. This pilot-scale (121–203 kg h−1) pelleting study generated detailed knowledge on the densification of torrefied biomass compared to untreated biomass. Four feedstock with high supply availability (beech, poplar, wheat straw and corn cob) were studied in their untreated and torrefied forms. Systematic methods were used to produce 180 batches of 8 mm dia. pellets using press channel length (PCL) and moisture content (MC) ranges of 30–60 mm and 7.3–16.6% (wet basis) respectively. Analysis showed that moderate degrees of torrefaction (250–280 °C, 20–75 min) strongly affected pelleting behaviour. The highest quality black pellets had a mechanical durability and bulk density range of 87.5–98.7% and 662–697 kg m−3 respectively. Pelleting energy using torrefied feedstock varied from −15 to +53 kWh t−1 from untreated with increases in production fines. Optimal pelleting MC and PCL were reduced significantly for torrefied feedstock and pellet quality was characterised by a decrease in mechanical durability and an increase in bulk density. Energy densities of 11.9–13.2 GJ m−3 (as received) were obtained

Influence of moisture contents on the fast pyrolysis of trommel fines in a bubbling fluidized bed reactor

In this study, the effect of moisture contents [2.69 wt% (bone-dry), 5 wt% and 10 wt%] on product yields and process conversion efficiency during fast pyrolysis of a pre-treated trommel fines feedstock was investigated at 500 °C. Experiments were carried out using a 300 g h −1 bubbling fluidised bed rig. Yields of organic liquids ranged from 15.2 to 19.6 wt% of feedstock, which decreased with increasing moisture content. Hence, the bone-dry feedstock gave the maximum yield and consequently the highest process conversion efficiency of 43%. Increased moisture content also led to increase formation of unidentified gas products, indicating increased conversion of organic liquids. Due to the high ash content of the feedstocks, about 52 wt% solid residues, containing around 82% ash was recovered in the char pot in each case. Hence, to maximize oil yields during fast pyrolysis, trommel fines would require extensive drying to remove the original 46 wt% moisture as well as reducing the ash content considerably. XRF analysis of the ash in the feedstock and solid residues showed that the main elements present included Ca, Si, Fe, Pb, K, Cl and Al. Apart from the presence of Pb (which may be from the glass contents of the feedstock), the solid residues could be used for land reclamation or co-incinerated at cement kilns for cement manufacture

The effect of a complementary e-learning course on implementation of a quality improvement project regarding care for elderly patients: a stepped wedge trial

<p>Abstract</p> <p>Background</p> <p>Delirium occurs frequently in elderly hospitalised patients and is associated with higher mortality, increased length of hospital stay, functional decline, and admission to long-term care. Healthcare professionals frequently do not recognise delirium, indicating that education can play an important role in improving delirium care for hospitalised elderly. Previous studies have indicated that e-learning can provide an effective way of educating healthcare professionals and improving quality of care, though results are inconsistent.</p> <p>Methods and design</p> <p>This stepped wedge cluster randomised trial will assess the effects of a complementary delirium e-learning course on the implementation of quality improvement initiative, which aims to enhance the recognition and management of delirium in elderly patients. The trial will be conducted in 18 Dutch hospitals and last 11 months. Measurements will be taken in all participating wards using monthly record reviews, in order to monitor delivered care. These measurements will include the percentage of elderly patients who were screened for the risk of developing delirium, use of the Delirium Observation Screening scale, use of nursing or medical interventions, and the percentage of elderly patients who were diagnosed with delirium. Data regarding the e-learning course will be gathered as well. These data will include user characteristics, information regarding use of the course, delirium knowledge before and after using the course, and the attitude and intentions of nurses concerning delirium care.</p> <p>Setting</p> <p>The study will be conducted in internal medicine and surgical wards of eighteen hospitals that are at the beginning stages of implementing the Frail Elderly Project in the Netherlands.</p> <p>Discussion</p> <p>Better recognition of elderly patients at risk for delirium and subsequent care is expected from the introduction of an e-learning course for nurses that is complementary to an existing quality improvement project. This trial has the potential to demonstrate that e-learning can be a vital part of the implementation process, especially for quality improvement projects aimed at complex health issues such as delirium. The study will contribute to a growing body of knowledge concerning e-learning and the effects it can have on knowledge as well as delivered care.</p> <p>Trial registration</p> <p>Netherlands Trial Register (NTR): <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2885">NTR2885</a></p

Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN

Real-Time Dynamics of Ca2+, Caspase-3/7, and Morphological Changes in Retinal Ganglion Cell Apoptosis under Elevated Pressure

Quantitative information on the dynamics of multiple molecular processes in individual live cells under controlled stress is central to the understanding of the cell behavior of interest and the establishment of reliable models. Here, the dynamics of the apoptosis regulator intracellular Ca2+, apoptosis effector caspase-3/7, and morphological changes, as well as temporal correlation between them at the single cell level, are examined in retinal gangling cell line (differentiated RGC-5 cells) undergoing apoptosis at elevated hydrostatic pressure using a custom-designed imaging platform that allows long-term real-time simultaneous imaging of morphological and molecular-level physiological changes in large numbers of live cells (beyond the field-of-view of typical microscopy) under controlled hydrostatic pressure. This examination revealed intracellular Ca2+ elevation with transient single or multiple peaks of less than 0.5 hour duration appearing at the early stages (typically less than 5 hours after the onset of 100 mmHg pressure) followed by gradual caspase-3/7 activation at late stages (typically later than 5 hours). The data reveal a strong temporal correlation between the Ca2+ peak occurrence and morphological changes of neurite retraction and cell body shrinkage. This suggests that Ca2+ elevation, through its impact on ion channel activity and water efflux, is likely responsible for the onset of apoptotic morphological changes. Moreover, the data show a significant cell-to-cell variation in the onset of caspase-3/7 activation, an inevitable consequence of the stochastic nature of the underlying biochemical reactions not captured by conventional assays based on population-averaged cellular responses. This real-time imaging study provides, for the first time, statistically significant data on simultaneous multiple molecular level changes to enable refinements and testing of models of the dynamics of mitochondria-mediated apoptosis. Further, the platform developed and the approach has direct significance to the study of a variety of signaling pathway phenomena

Part II, Provider perspectives: should patients be activated to request evidence-based medicine? a qualitative study of the VA project to implement diuretics (VAPID)

<p>Abstract</p> <p>Background</p> <p>Hypertension guidelines recommend the use of thiazide diuretics as first-line therapy for uncomplicated hypertension, yet diuretics are under-prescribed, and hypertension is frequently inadequately treated. This qualitative evaluation of provider attitudes follows a randomized controlled trial of a patient activation strategy in which hypertensive patients received letters and incentives to discuss thiazides with their provider. The strategy prompted high discussion rates and enhanced thiazide-prescribing rates. Our objective was to interview providers to understand the effectiveness and acceptability of the intervention from their perspective, as well as the suitability of patient activation for more widespread guideline implementation.</p> <p>Methods</p> <p>Semi-structured phone interviews were conducted with 21 primary care providers. Interviews were transcribed verbatim and reviewed by the interviewer before being analyzed for content. Interviews were coded, and relevant themes and specific responses were identified, grouped, and compared.</p> <p>Results</p> <p>Of the 21 providers interviewed, 20 (95%) had a positive opinion of the intervention, and 18 of 20 (90%) thought the strategy was suitable for wider use. In explaining their opinions of the intervention, many providers discussed a positive effect on treatment, but they more often focused on the process of patient activation itself, describing how the intervention facilitated discussions by informing patients and making them more pro-active. Regarding effectiveness, providers suggested the intervention worked like a reminder, highlighted oversights, or changed their approach to hypertension management. Many providers also explained that the intervention 'aligned' patients' objectives with theirs, or made patients more likely to accept a change in medications. Negative aspects were mentioned infrequently, but concerns about the use of financial incentives were most common. Relevant barriers to initiating thiazide treatment included a hesitancy to switch medications if the patient was at or near goal blood pressure on a different anti-hypertensive.</p> <p>Conclusions</p> <p>Patient activation was acceptable to providers as a guideline implementation strategy, with considerable value placed on the activation process itself. By 'aligning' patients' objectives with those of their providers, this process also facilitated part of the effectiveness of the intervention. Patient activation shows promise for wider use as an implementation strategy, and should be tested in other areas of evidence-based medicine.</p> <p>Trial registration</p> <p>National Clinical Trial Registry number NCT00265538</p

Model and experiences of initiating collaboration with traditional healers in validation of ethnomedicines for HIV/AIDS in Namibia

Many people with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) in Namibia have access to antiretroviral drugs but some still use traditional medicines to treat opportunistic infections and offset side-effects from antiretroviral medication. Namibia has a rich biodiversity of indigenous plants that could contain novel anti-HIV agents. However, such medicinal plants have not been identified and properly documented. Various ethnomedicines used to treat HIV/AIDS opportunistic infections have not been scientifically validated for safety and efficacy. These limitations are mostly attributable to the lack of collaboration between biomedical scientists and traditional healers. This paper presents a five-step contextual model for initiating collaboration with Namibian traditional healers in order that candidate plants that may contain novel anti-HIV agents are identified, and traditional medicines used to treat HIV/AIDS opportunistic infections are subjected to scientific validation. The model includes key structures and processes used to initiate collaboration with traditional healers in Namibia; namely, the National Biosciences Forum, a steering committee with the University of Namibia (UNAM) as the focal point, a study tour to Zambia and South Africa where other collaborative frameworks were examined, commemorations of the African Traditional Medicine Day (ATMD), and consultations with stakeholders in north-eastern Namibia. Experiences from these structures and processes are discussed. All traditional healers in north-eastern Namibia were willing to collaborate with UNAM in order that their traditional medicines could be subjected to scientific validation. The current study provides a framework for future collaboration with traditional healers and the selection of candidate anti-HIV medicinal plants and ethnomedicines for scientific testing in Namibia