8,533 research outputs found
Tests on the efficiency of the power plant at the Kansas State Agricultural College
Citation: Fockele, Glick and Cole, Murray S. Tests on the efficiency of the power plant at the Kansas State Agricultural College. Senior thesis, Kansas State Agricultural College, 1902.Morse Department of Special CollectionsIntroduction: The plant is designed to furnish heat and power for the various departments at the Kansas State Agricultural College of Manhattan, Kansas. It was originally intended by the writers to include in their work, tests on the heating power of the plant, but the arrangement of their other college work during the year, made it impossible for them to conduct the experiments at a time when the heating plant was in operation. Another drawback was the absence of suitable apparatus for the determination of the calorific power of the coal. The heating plant consists of six externally fired, horizontal, multitubular boilers, designated as No. 1, 2, 3, 4, 5 and 6. Five are of 60 nominal horsepower and one, No. 6, is of 100 nominal horsepower. The tests were conducted upon No. 1, for the reason that it was the only high pressure boiler which was piped for individual feed water, and with this boiler is our interest concerned. None of the connections with other boilers could possibly affect results of these tests except in the test on April 28th, when No. 3 was turned in on account of the heavy load on the engine. In this case neither boiler made more steam than the engine could use, so the pressure in neither one was affected in the least and the conditions of the test were kept uniform. The boiler itself is 54â diameter, with 34 flues 3-3/4 inches in diameter and 16 feet long. The grates are 4-1/2â by 4-1/2â. The boiler was built by Joseph Bromich of Topeka, Kansas. It was installed in 1896. It was in very good condition for all tests. The fuel used was the coal furnished by the state for use in the institution, and was of very poor quality. It comes from the state mines near Leavenworth, and is mined by the prisoners from the state penitentiary
Ejection of Supernova-Enriched Gas From Dwarf Disk Galaxies
We examine the efficiency with which supernova-enriched gas may be ejected
from dwarf disk galaxies, using a methodology previously employed to study the
self-enrichment efficiency of dwarf spheroidal systems. Unlike previous studies
that focused on highly concentrated starbursts, in the current work we consider
discrete supernova events spread throughout various fractions of the disk. We
model disk systems having gas masses of 10^8 and 10^9 solar masses with
supernova rates of 30, 300, and 3000 per Myr. The supernova events are confined
to the midplane of the disk, but distributed over radii of 0, 30, and 80% of
the disk radius, consistent with expectations for Type II supernovae. In
agreement with earlier studies, we find that the enriched material from
supernovae is largely lost when the supernovae are concentrated near the
nucleus, as expected for a starburst event. In contrast, however, we find the
loss of enriched material to be much less efficient when the supernovae occur
over even a relatively small fraction of the disk. The difference is due to the
ability of the system to relax following supernova events that occur over more
extended regions. Larger physical separations also reduce the likelihood of
supernovae going off within low-density "chimneys" swept out by previous
supernovae. We also find that, for the most distributed systems, significant
metal loss is more likely to be accompanied by significant mass loss. A
comparison with theoretical predications indicates that, when undergoing
self-regulated star formation, galaxies in the mass range considered shall
efficiently retain the products of Type II supernovae.Comment: 16 pages, 14 figures, to appear in Astrophysical Journal; higher
resolution figures available through Ap
Roche Lobe Overflow from Dwarf Stellar Systems
We use both analytical analyses and numerical simulations to examine the
evolution of residual gas within tidally-limited dwarf galaxies and globular
clusters. If the gas sound speed exceeds about 10% of the central velocity
dispersion, as is the case for ionized gas within small stellar systems, the
gas shall have significant density at the tidal radius, and the gas may be lost
on timescales as short as a few times the sound crossing time of the system. In
colder systems, the density at the tidal radius is much lower, greatly reducing
the mass loss rate, and the system may retain its gas for a Hubble time. The
tidally removed gas shall follow an orbit close to that of the original host
system, forming an extended stream of ionized, gaseous debris. Tidal mass loss
severely limits the ability of dwarf systems to continuously form stars. The
ordinary gas content in many dwarf galaxies is fully ionized during high
red-shift epochs, possibly preventing star formation in some systems, leading
to the formation of starless, dark-matter concentrations. In either the field
or in the center of galaxy clusters, ionized gas may be retained by dwarf
galaxies, even though its sound speed may be comparable to or even exceed the
velocity dispersion. These processes may help to explain some observed
differences among dwarf galaxy types, as well as observations of the haloes of
massive galaxies.Comment: 28 pages, LaTeX, AASTex macro
What Would I Know About Mercy? Faith and Optimistic Expectancies Among African Americans
A small body of research has begun to explore the association between faith and optimism among African Americans. However, missing from the extant work is an examination of the extent to which traditional indices of religious commitment work together with beliefs about God to shape optimism. The present study examines the utility of indices of social location, religious commitment (i.e., early and current religious service attendance, subjective religiosity), belief about the quality of oneâs relationship with God (i.e., a belief that one is connected to a loving God), and beliefs about being the recipient of divine forgiveness for predicting dispositional optimism among a sample of community residing African American adults (N = 241). Age, subjective religiosity, and organizational religiosity were positively related to optimism in bivariate analyses. Hierarchical regression analyses demonstrated a significant association between age, subjective religiosity, and optimism; however, those associations were eliminated once relationship with God and belief in oneâs forgiveness by God were entered into the model. Only belief in Godâs love predicted optimism in multivariate analyses. Serial mediation analyses revealed that beliefs about the quality of oneâs relationship with God and belief in divine forgiveness fully mediated the relationship between subjective religiosity and optimism, but that the relationship is driven largely by relationship with God. Implications of these findings are discussed
Supernova Enrichment of Dwarf Spheroidal Galaxies
(Abridged) Many dwarf galaxies exhibit sub-Solar metallicities, with some
star-to-star variation, despite often containing multiple generations of stars.
The total metal content in these systems is much less than expected from the
heavy element production of massive stars in each episode of star formation.
Such a deficiency implies that a substantial fraction of the enriched material
has been lost from these small galaxies. Mass ejection from dwarf galaxies may
have important consequences for the evolution of the intergalactic medium and
for the evolution of massive galaxies, which themselves may have formed via the
merger of smaller systems. We report here the results of three-dimensional
simulations of the evolution of supernova-enriched gas within dwarf spheroidal
galaxies (dSph's), with the aim of determining the retention efficiency of
supernova ejecta. We consider two galaxy models, selected to represent opposite
ends of the dSph sequence. For each model galaxy we investigate a number of
scenarios, ranging from a single supernova in smooth gas distributions to more
complex multiple supernovae in highly disturbed gas distributions. The results
of these investigations suggest that, for low star-formation efficiencies, it
is difficult to completely expel the enriched material from the galaxy. Most of
the enriched gas is, however, lost from the core of the galaxy following
multiple supernovae, especially if the interstellar medium is already highly
disturbed by processes such as photo-ionization and stellar winds. If
subsequent star formation occurs predominantly within the core where most of
the residual gas is concentrated, then these results could explain the poor
self-enrichment efficiency observed in dwarf galaxies.Comment: 29 pages, 10 figures, to appear in Astrophysical Journa
Early postpartum restingâstate functional connectivity for mothers receiving buprenorphine treatment for opioid use disorder: A pilot study
Between 1999 and 2014, the prevalence of opioid use disorder (OUD) among pregnant women quadrupled in the USA. The standard treatment for peripartum women with OUD is buprenorphine. However, the maternal behavior neurocircuit that regulates maternal behavior and motherâinfant bonding has not been previously studied for human mothers receiving buprenorphine treatment for OUD (BT). Rodent research shows opioid effects on reciprocal inhibition between maternal care and defence maternal brain subsystems: the hypothalamus and periaqueductal gray, respectively. We conducted a longitudinal functional magnetic resonance imaging (fMRI) pilot study in humans to specifically examine restingâstate functional connectivity (rsâFC) between the periaqueductal gray and hypothalamus, as well as to explore associations with maternal bonding for BT. We studied 32 mothers who completed fMRI scans at 1Â month (T1) and 4Â months postpartum (T2), including seven mothers receiving buprenorphine for OUD and 25 nonâOUD mothers as a comparison group (CG). The participants underwent a 6âminute restingâstate fMRI scan at each time point. We measured potential bonding impairments using the Postpartum Bonding Questionnaire to explore how rsâFC with periaqueductal gray is associated with bonding impairments. Compared to CG, BT mothers differed in periaqueductal grayâdependent rsâFC with the hypothalamus, amygdala, insular cortex and other brain regions at T1, with many of these differences disappearing at T2, suggesting potential therapeutic effects of continuing buprenorphine treatment. In contrast, the ârejection and pathological angerâ subscale of the Postpartum Bonding Questionnaire at T1 and T2 was associated with the T1âtoâT2 increases in periaqueductal grayâdependent rsâFC with the hypothalamus and amygdala. Preliminary evidence links maternal bonding problems for mothers with OUD early in the postpartum to connectivity between specific care and defence maternal brain circuits, which may be mitigated by buprenorphine treatment. This exploratory study supports a potential mechanism for investigating both the therapeutic benefits and risks of opioids for maternal care and bonding with infants.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151866/1/jne12770.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151866/2/jne12770_am.pd
Germline mutations in the oncogene EZH2 cause Weaver syndrome and increased human height.
The biological processes controlling human growth are diverse, complex and poorly understood. Genetic factors are important and human height has been shown to be a highly polygenic trait to which common and rare genetic variation contributes. Weaver syndrome is a human overgrowth condition characterised by tall stature, dysmorphic facial features, learning disability and variable additional features. We performed exome sequencing in four individuals with Weaver syndrome, identifying a mutation in the histone methyltransferase, EZH2, in each case. Sequencing of EZH2 in additional individuals with overgrowth identified a further 15 mutations. The EZH2 mutation spectrum in Weaver syndrome shows considerable overlap with the inactivating somatic EZH2 mutations recently reported in myeloid malignancies. Our data establish EZH2 mutations as the cause of Weaver syndrome and provide further links between histone modifications and regulation of human growth
An Exploration of Community Palliative Care Clinical Nurse Specialists Experiences of Working as Independent Prescribers: Part 2
The Department of Health has recently reiterated its commitment to the improvement in the quality of end of life care and emphasized the importance of all patients having rapid access to medication. The aim of this study was to explore the lived experiences of clinical nurse specialists who are able to prescribe independently in their role in providing support for patients with palliative care needs within the community setting. Interpretive phenomenology was employed in order to understand and interpret the experiences of six nurse independent prescribes employed as community palliative care clinical nurse specialists. This purposive sampling was preferred with semi-structured interviews as the most appropriate data collection technique. Participants interviewed reported that being able to prescribe enabled them to provide seamless, holistic care which facilitated faster access to medicines for their patients. This was particularly apparent at weekends when the patient's usual general practitioner (GP) was unavailable. Several benefits of nurse independent prescribing were also highlighted. However, the main barrier identified by most participants was the difficulty in accessing the patient's records. The overwhelming conclusion was that independent prescribing by community nurse specialists is beneficial for patients in the palliative care phase of their life and those deemed important to them as they are being cared for at home. Such benefits can also impact on other aspects of the patient's life including prompt availability of medicines, effective symptom control and consequently, an improved or enhanced quality of life for the patients and job satisfaction for the prescribing specialists nurses
- âŠ