Characteristics of pine needle combustion in a semi-gasifier burner

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, June 2011."June 2011." Cataloged from PDF version of thesis.Includes bibliographical references (p. 29).The motivation behind this report was to develop a stronger understanding of pine needle combustion behavior in a semi-gasifier, in order to ultimately design an effective pine needle cook stove for people in the developing world. Pine needles are a cheap, energy-dense fuel source that can be harnessed for cooking purposes, but they are often physically or chemically altered prior to being used as a fuel. The challenge remains to develop a stove that uses unprocessed pine needles. Using principles of a semi-gasification biomass stove, this paper explores the combustion and burn characteristics of unprocessed pine needles by measuring the effects of temperature in a configured burner when altering primary and secondary airflow into the burner. Experiments showed that pine needles in a semi-gasifier combust in two regimes--one characterized by secondary combustion of volatiles released from the primary burn of raw pine needles, and another characterized by the smoldering of pine needle charcoal. Each regime needed unique balances between primary air and secondary airflow. The first regime required a relatively low primary airflow with a high secondary airflow, while the second regime needed a high primary airflow to maintain charring and low or no secondary airflow. The balance of airflow in the first regime was crucial in determining whether the volatiles combusted or were released as plumes of smoke. The findings of this report can be used as an initial benchmark and resource in the further development of an existing proof-of-concept prototype, which was built by the authors with a team of MIT students and affiliates and a community partner in Uttarakhand, India.by Liane Jessica Fang and Caroline M. Hane-Weijman.S.B

Harvesting the results of the mentoring process of knowledge intensive startups

Mentoring is often used by business development programs to assist startups. In this paper we look at the perceptions of protégés and mentors about this process, hereby different business development programs in Europe were incorporated. It was hypothesized that there is a relationship between contact frequency and amount of support delivered to the protégé. This hypothesis was partly supported. Furthermore we hypothesized that if the amount of support is higher that the positive associated outcomes like trust and benefits to the protégé also will be higher. This hypothesis was mainly supported for the benefits of the protégé. Last also the relation between short and long term outcomes was hypothesized. The research showed that there is a relation between the benefits and the profoundness of the relation in the long term. The corresponding implication for program managers are discussed below

Dark matter measurements combining stellar and HI kinematics: 30% 1−σ1-\sigma outliers with low dark matter content at 5Re5R_\mathrm{e}

We construct the Schwarzschild dynamical models for 11 early-type galaxies with the SAURON and Mitchell stellar IFUs out to $2-4 R_\mathrm{e}$, and construct dynamical models with combined stellar and HI kinematics for a subsample of 4 galaxies with HI velocity fields out to $10 R_\mathrm{e}$ obtained from the Westerbork Synthesis Radio Telescope, thus robustly obtaining the dark matter content out to large radii for these galaxies. Adopting a generalised-NFW dark matter profile, we measure an NFW-like density cusp in the dark matter inner slopes for all sample galaxies, with a mean value of $1.00\pm0.04$ (rms scatter $0.15$). The mean dark matter fraction for the sample is $0.2$ within $1 R_\mathrm{e}$, and increases to $0.4$ at $2 R_\mathrm{e}$, and $0.6$ at $5 R_\mathrm{e}$. The dark matter fractions within $1 R_\mathrm{e}$ of these galaxies are systematically lower than the predictions of both the TNG-100 and EAGLE simulations. For the dark matter fractions within $2 R_\mathrm{e}$ and $5 R_\mathrm{e}$, 40% and 70% galaxies are $1-\sigma$ consistent with either the TNG-100 or the EAGLE predictions, while the remaining 60% and 30% galaxies lie below the $1-\sigma$ region. Combined with 36 galaxies with dark matter fractions measured out to $5 R_\mathrm{e}$ in the literature, about 10% of these 47 galaxies lie below the $3-\sigma$ region of the TNG-100 or EAGLE predictions.Comment: 15 pages, 9 figures, accepted by MNRA

Roles for CEP170 in cilia function and dynein-2 assembly

Primary cilia are essential eukaryotic organelles required for signalling and secretion. Dynein-2 is a microtubule-motor protein complex and is required for ciliogenesis via its role in facilitating retrograde intraflagellar transport (IFT) from the cilia tip to the cell body. Dynein-2 must be assembled and loaded onto IFT trains for entry into cilia for this process to occur, but how dynein-2 is assembled and how it is recycled back into a cilium remain poorly understood. Here, we identify centrosomal protein of 170 kDa (CEP170) as a dynein-2-interacting protein in mammalian cells. We show that loss of CEP170 perturbs intraflagellar transport and hedgehog signalling, and alters the stability of dynein-2 holoenzyme complex. Together, our data indicate a role for CEP170 in supporting cilia function and dynein-2 assembly

Exposure to violence is not associated with accuracy in forecasting conflict outcomes

Exposure to harsh or unpredictable environments can impair social and cognitive functioning. However, people may also develop enhanced abilities for solving challenges relevant in those environments (‘hidden talents’). In the current study, we explored the associations between people’s ability to accurately forecast conflict outcomes and their past and current experiences with violence. To do so, we used dynamic, real-world videos with known outcomes, rather than static, artificial stimuli (e.g., vignettes) with unknown outcomes, as previous research has done. We conducted a preregistered study in the Netherlands that included a final sample of 127 participants: 63 from a community sample and 64 college students. We found no support for our core hypothesis that people who experienced more violence are more accurate in forecasting conflict outcomes. Thus, we did not find support for hidden talents, contributing to an evidence base that was already mixed and inconclusive. We did find support for our auxiliary hypothesis that college students would wear ‘rose-colored glasses’, underestimating the number of conflicts that would escalate into fights. Contrary to our other two auxiliary hypotheses, the community sample did not overestimate the number of conflicts that would escalate into fights, and people who have experienced more violence were not more likely to predict that conflicts will escalate into fights. These findings have implications for the literature on hostile attribution bias, which shows that people with more exposure to violence more likely interpret the ambiguous actions of others as hostile. Whereas this pattern is often attributed to negativity bias in people with more exposure to violence, it might also reflect rose-colored glasses on people living safer lives

Nationwide Evaluation of Congenital Hypothyroidism Screening during Neonatal Extracorporeal Membrane Oxygenation

Background: Thyroid hormone concentrations may deviate from normal values during critical illness. This condition is known as nonthyroidal illness syndrome (NTIS), and it can influence the results of screening for congenital hypothyroidism (CH) during neonatal extracorporeal membrane oxygenation (ECMO). Objectives: To determine the incidence of aberrant CH screening results in ECMO-treated neonates, to identify possible determinants, and to follow up patients with abnormal thyroid hormone concentrations. Methods: In this retrospective cohort study, we included 168 ECMO-treated neonates admitted from 2004 to 2014 and screened by protocol and divided them into the following 3 groups: group 1 (screened during ECMO, n = 107), group 2 (screened shortly before ECMO, n = 26), and group 3 (screened shortly after ECMO, n = 35). Results: CH screening results were aberrant in 67.3% (72/107) of the neonates screened during ECMO, in 73.1% (19/26) of the neonates screened before ECMO, and in 31.4% (11/35) of the neonates screened after ECMO (p < 0.001). Of the neonates with an aberrant screening result, all but 2 (i.e. 98%) had a low thyroxine concentration with a normal thyrotropin concentration at screening, as is seen in NTIS. None was diagnosed with CH. Mortality did not significantly differ between neonates with an aberrant screening result (32.4%) and neonates with a normal screening result (22.7%; p = 0.18). Screening before ECMO (OR 5.92; 95% CI 1.93-18.20), screening during ECMO (OR 4.49; 95% CI 1.98-10.19), and a higher Pediatric Logistic Organ Dysfunction-2 score (OR 1.31; 95% CI 1.04-1.66) were associated with an aberrant screening result. Conclusions: Aberrant CH screening results were found in most ECMO-treated neonates screened before or during ECMO, which is likely due to NTIS. Follow-up of thyroid hormone concentrations is best started after recovery from critical illness. Our results suggest that thyroxine therapy is not required during ECMO

Molecular mechanism for kinesin-1 direct membrane recognition

The cargo-binding capabilities of cytoskeletal motor proteins have expanded during evolution through both gene duplication and alternative splicing. For the light chains of the kinesin-1 family of microtubule motors, this has resulted in an array of carboxyl-terminal domain sequences of unknown molecular function. Here, combining phylogenetic analyses with biophysical, biochemical, and cell biology approaches, we identify a highly conserved membrane-induced curvature-sensitive amphipathic helix within this region of a subset of long kinesin light-chain paralogs and splice isoforms. This helix mediates the direct binding of kinesin-1 to lipid membranes. Membrane binding requires specific anionic phospholipids, and it contributes to kinesin-1\u2013dependent lysosome positioning, a canonical activity that, until now, has been attributed exclusively the recognition of organelle-associated cargo adaptor proteins. This leads us to propose a protein-lipid coincidence detection framework for kinesin-1\u2013mediated organelle transport

Decision-making about the use of hormone therapy among perimenopausal women

Women reaching menopause must make a controversial decision about whether to use hormone therapy (HT). The theory of planned behaviour (TPB) was the organizing framework. The objectives were to determine if (1) influence of different TPB constructs varied with stage of menopause and HT use, (2) women with diabetes were influenced in significantly different ways from women without, (3) the overall perceived behavioural control (PBC) and self-efficacy (SE) have independent effects on intention, and (4) physician influence was mediated by subjective norm (SN).Cross-sectional survey of women from a managed care organization.Multiple regression analysis was used to analyse 765 responses (230 from women with diabetes) and separately four main subgroups: (1) early menopause stage and never used HT, (2) late menopause stage and never used HT, (3) late menopause stage and previously used HT, and (4) late menopause stage currently using HT.For the entire sample, the model explains 68% of variance in intention, where SE, physicians' influence, self-identification with menopause as a natural part of ageing, self-identification as someone who wants to delay menopause, HT status, menopause status, and diabetes were added to the TPB. For the entire sample, SE added 2% to the explained variance and the physician determinant added 7%.An augmented TPB is useful for understanding women's HT use decisions. The theory explains more variance in intention before a behaviour is enacted than after, and decision structure changes over time. PBC and SE have independent effects on intention.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79377/1/135910709X457946.pd