1,357 research outputs found
Organics and Ices in the Outer Solar System: Connections to the Interstellar Medium
The solar nebula, that aggregate of gas and dust that formed the birthplace of the Sun, planets and plethora of small bodies comprising the Solar System, originated in a molecular cloud that is thought to have spawned numerous additional stars, some with their own planets and attendant small bodies. The question of the chemical and physical reprocessing of the original interstellar materials in the solar nebula has challenged both theory and observations. The acquisition and analysis of samples of comet and asteroid solids, and a growing suite of in-situ and close-up analyses of relatively unaltered small Solar System bodies now adds critical new dimensions to the study of the origin and evolution of the early solar nebula. Better understanding the original composition of the material from which our solar nebula formed, and the processing that material experienced, will aid in formulations of chemistry that might occur in other solar systems. While we seek to understand the compositional history of planetary bodies in our own Solar System, we will inevitably learn more about the materials that comprise exoplanets and their surrounding systems
Interstellar Organics, the Solar Nebula, and Saturn's Satellite Phoebe
The diffuse interstellar medium inventory of organic material (Pendleton et al. 1994, Pendleton & Allamandola 2002) was likely incorporated into the molecular cloud in which the solar nebula condensed. This provided the feedstock for the formation of the Sun, major planets, and the smaller icy bodies in the region outside Neptune's orbit (transneptunian objects, or TNOs). Saturn's satellites Phoebe, Iapetus, and Hyperion open a window to the composition of one class of TNO as revealed by the near-infrared mapping spectrometer (VIMS) on the Cassini spacecraft at Saturn. Phoebe (mean diameter 213 km) is a former TNO now orbiting Saurn. VIMS spaectral maps of PHoebe's surface reveal a complex organic spectral signature consisting of prominent aromatic (CH) and alophatic hydrocarbon (CH2, CH3) absorption bands (3.2-3.6 micrometers). Phoebe is the source of a huge debris ring encircling Saturn, and from which particles (approximately 5-20 micrometer size) spiral inward toward Saturn. They encounter Iapetus and Hperion where they mix with and blanket the native H2O ice of those two bodies. Quantitative analysis of the hydrocarbon bands on Iapetus demonstrates that aromatic CH is approximately 10 times as abundant as aliphatic CH2+CH3, significantly exceeding the strength of the aromatic signature in interplanetary dust particles, comet particles, ad in carbonaceous meteorites (Cruikshank et al. 2013). A similar excess of aromatics over aliphatics is seen in the qualitative analysis of Hyperion and Phoebe itself (Dalle Ore et al. 2012). The Iapetus aliphatic hydrocarbons show CH2/CH3 approximately 4, which is larger than the value found in the diffuse ISM (approximately 2-2.5). In so far as Phoebe is a primitive body that formed in the outer regions of the solar nebula and has preserved some of the original nebula inventory, it can be key to understanding the content and degree of procesing of the nebular material. There are other Phoebe-like TNOs that are presently beyond our ability to study in the organic spectral region, but JWST will open that possibility for a number of objects. We now need to explore and understand the connection of this organic-bearing Solar System material to the solar nebula the the inventory of ISM materials incorporated therein
The Effects of Some Nitrogen Fertilizers on Nitrification
A number of investigations have shown the effects of certain nitrogen fertilizers on the nitrification process and it has generally been noted that nitrates would stimulate the production of nitrates. The work of Coleman, Brown and Gowda and Greaves may be referred to in this connection
Working collaboratively to support people living with dementia
This short paper introduces the âliving labâ concept in dementia care and outlines its value as an innovative and cost-effective strategy
Spectral Hardness Decay with Respect to Fluence in BATSE Gamma-Ray Bursts
We have analyzed the evolution of the spectral hardness parameter Epk as a
function of fluence in gamma-ray bursts. We fit 41 pulses within 26 bursts with
the trend reported by Liang & Kargatis (1996) which found that Epk decays
exponentially with respect to photon fluence. We also fit these pulses with a
slight modification of this trend, where Epk decays linearly with energy
fluence. In both cases, we found the set of 41 pulses to be consistent with the
trend. For the latter trend, which we believe to be more physical, the
distribution of the decay constant is roughly log-normal, with a mean of 1.75
+/- 0.07 and a FWHM of 1.0 +/- 0.1. Regarding an earlier reported invariance in
the decay constant among different pulses in a single burst, we found
probabilities of 0.49 to 0.84 (depending on the test used) that such invariance
would occur by coincidence, most likely due to the narrow distribution of decay
constant values among pulses.Comment: 17 pages, 7 figure pages, 2 table pages, submitted to The
Astrophysical Journa
A Method for Balancing Provider Schedules in Outpatient Specialty Clinics
Background. Variability in outpatient specialty clinic schedules contributes to numerous adverse effects including chaotic clinic settings, provider burnout, increased patient waiting times, and inefficient use of resources. This research measures the benefit of balancing provider schedules in an outpatient specialty clinic. Design. We developed a constrained optimization model to minimize the variability in provider schedules in an outpatient specialty clinic. Schedule variability was defined as the variance in the number of providers scheduled for clinic during each hour the clinic is open. We compared the variance in the number of providers scheduled per hour resulting from the constrained optimization schedule with the actual schedule for three reference scenarios used in practice at M Health Fairviewâs Clinics and Surgery Center as a case study. Results. Compared to the actual schedules, use of constrained optimization modeling reduced the variance in the number of providers scheduled per hour by 92% (1.70â0.14), 88% (1.98â0.24), and 94% (1.98â0.12). When compared with the reference scenarios, the total, and per provider, assigned clinic hours remained the same. Use of constrained optimization modeling also reduced the maximum number of providers scheduled during each of the actual schedules for each of the reference scenarios. The constrained optimization schedules utilized 100% of the available clinic time compared to the reference scenario schedules where providers were scheduled during 87%, 92%, and 82% of the open clinic time, respectively. Limitations. The scheduling modelâs use requires a centralized provider scheduling process in the clinic. Conclusions. Constrained optimization can help balance provider schedules in outpatient specialty clinics, thereby reducing the risk of negative effects associated with highly variable clinic settings
Sustainable Competitive Advantage of Internet Firms - A Strategic Framework and Implications for Global Marketers
Purpose â At the core of an international marketing strategy is the internet firmâs goal of building and sustaining a competitive advantage. The purpose of this paper is to present an integrative framework to explain the role that customer behavior and customer relationship management (CRM) play in developing a profitable, sustainable competitive advantage for internet companies.
Design/methodology/approach â The integrative framework utilizes existing theoretical concepts from the areas of strategy and internet marketing and develops a framework to provide firms with insights into how they can gain the competitive advantage. Findings â This paper links global customer behavior to the firmsâ business value chain and provides guidelines for strategic implications. In this conceptual paper, it is discussed that understanding consumer decision-making behavior on the web and managing these relationships are critically important to achieve a superior performance.
Research limitations/implications â This is not empirical research. A theoretical model is presented for future testing by researchers using statistical techniques such as structural equation modeling. Practical implications â The framework provides managerial insights into building and sustaining a competitive advantage using a consumer-centric approach, coupled with CRM technology on a global scale. Managerial value is derived by providing an understanding of the link between a sustainable competitive advantage, customer-focused strategies, consumersâ needs and wants, the firmâs performance, and shareholder value.
Originality/value â It is important for global marketers to understand how consumer decision-making on the web affects strategic and financial performance. This paper extends the current literature by integrating consumer decision behavior on the web, CRM, and the firmsâ performance. This framework explains the creation of a sustainable competitive advantage using customer-focused strategies to develop customer loyalty for superior firm performance
Sustainable Competitive Advantage of Internet Firms - A Strategic Framework and Implications for Global Marketers
Purpose â At the core of an international marketing strategy is the internet firmâs goal of building and sustaining a competitive advantage. The purpose of this paper is to present an integrative framework to explain the role that customer behavior and customer relationship management (CRM) play in developing a profitable, sustainable competitive advantage for internet companies.
Design/methodology/approach â The integrative framework utilizes existing theoretical concepts from the areas of strategy and internet marketing and develops a framework to provide firms with insights into how they can gain the competitive advantage. Findings â This paper links global customer behavior to the firmsâ business value chain and provides guidelines for strategic implications. In this conceptual paper, it is discussed that understanding consumer decision-making behavior on the web and managing these relationships are critically important to achieve a superior performance.
Research limitations/implications â This is not empirical research. A theoretical model is presented for future testing by researchers using statistical techniques such as structural equation modeling. Practical implications â The framework provides managerial insights into building and sustaining a competitive advantage using a consumer-centric approach, coupled with CRM technology on a global scale. Managerial value is derived by providing an understanding of the link between a sustainable competitive advantage, customer-focused strategies, consumersâ needs and wants, the firmâs performance, and shareholder value.
Originality/value â It is important for global marketers to understand how consumer decision-making on the web affects strategic and financial performance. This paper extends the current literature by integrating consumer decision behavior on the web, CRM, and the firmsâ performance. This framework explains the creation of a sustainable competitive advantage using customer-focused strategies to develop customer loyalty for superior firm performance
Gamma photometric redshifts for long gamma-ray bursts
It is known that the soft tail of the gamma-ray bursts' spectra show excesses
from the exact power-law dependence. In this article we show that this
departure can be detected in the peak flux ratios of different BATSE DISCSC
energy channels. This effect allows to estimate the redshift of the bright long
gamma-ray bursts in the BATSE Catalog. A verification of these redshifts is
obtained for the 8 GRB which have both BATSE DISCSC data and measured optical
spectroscopic redshifts. There is good correlation between the measured and
esti redshifts, and the average error is . The method is
similar to the photometric redshift estimation of galaxies in the optical
range, hence it can be called as "gamma photometric redshift estimation". The
estimated redshifts for the long bright gamma-ray bursts are up to . For the the faint long bursts - which should be up to - the
redshifts cannot be determined unambiguously with this method.Comment: accepted in A&A, 7 pages incl. 7 figure
- âŠ