12,647 research outputs found
Recommended from our members
A common phytoene synthase mutation underlies white petal varieties of the California poppy.
The California poppy (Eschscholzia californica) is renowned for its brilliant golden-orange flowers, though white petal variants have been described. By whole-transcriptome sequencing, we have discovered in multiple white petal varieties a single deletion leading to altered splicing and C-terminal truncation of phytoene synthase (PSY), a key enzyme in carotenoid biosynthesis. Our findings underscore the diverse roles of phytoene synthase in shaping horticultural traits, and resolve a longstanding mystery of the regaled golden poppy
A remark on non-integral -adic slopes for modular forms
We give a sufficient condition, namely “Buzzard irregularity”,
for there to exist a cuspidal eigenform which does not have integral
-adic slope.Accepted manuscrip
The relation between solar cell flight performance data and materials and manufacturing data Quarterly report
Analysis of flight performance data for solar cell power systems in satellite
On the freeness of anticyclotomic selmer groups of modular forms
We establish the freeness of certain anticyclotomic Selmer groups of modular forms. The freeness of these Selmer groups plays a key role in the Euler system arguments introduced by Bertolini and Darmon in their work on the anticyclotomic main conjecture for modular forms. In particular, our result fills some implicit gaps which appeared in generalizations of the Bertolini-Darmon result to the case where the associated residual representation is not minimally ramified. The removal of such a minimal ramification hypothesis is essential for applications involving congruences of modular forms.Accepted manuscrip
Temperature and pressure measurement techniques for an advanced turbine test facility
A high pressure, high-temperature turbine test facility constructed for use in turbine cooling research is described. Several recently developed temperature and pressure measuring techniques are used in this facility. The measurement techniques, their status, previous applications and some results are discussed. Noncontact surface temperature measurements are made by optical methods. Radiation pyrometry principles combined with photoelectric scanning are used for rotating components and infrared photography for stationary components. Contact (direct) temperature and pressure measurements on rotating components are expected to be handled with an 80 channel rotary data package which mounts on and rotates with the turbine shaft at speeds up to 17,500 rpm. The data channels are time-division multiplexed and converted to digital words in the data package. A rotary transformer couples power and digital data to and from the shaft
Demonstration of the Zero-Crossing Phasemeter with a LISA Test-bed Interferometer
The Laser Interferometer Space Antenna (LISA) is being designed to detect and
study in detail gravitational waves from sources throughout the Universe such
as massive black hole binaries. The conceptual formulation of the LISA
space-borne gravitational wave detector is now well developed. The
interferometric measurements between the sciencecraft remain one of the most
important technological and scientific design areas for the mission.
Our work has concentrated on developing the interferometric technologies to
create a LISA-like optical signal and to measure the phase of that signal using
commercially available instruments. One of the most important goals of this
research is to demonstrate the LISA phase timing and phase reconstruction for a
LISA-like fringe signal, in the case of a high fringe rate and a low signal
level. We present current results of a test-bed interferometer designed to
produce an optical LISA-like fringe signal previously discussed in the
literature.Comment: find minor corrections in the CQG versio
Universality in Three- and Four-Body Bound States of Ultracold Atoms
Under certain circumstances, three or more interacting particles may form
bound states. While the general few-body problem is not analytically solvable,
the so-called Efimov trimers appear for a system of three particles with
resonant two-body interactions. The binding energies of these trimers are
predicted to be universally connected to each other, independent of the
microscopic details of the interaction. By exploiting a Feshbach resonance to
widely tune the interactions between trapped ultracold lithium atoms, we find
evidence for two universally connected Efimov trimers and their associated
four-body bound states. A total of eleven precisely determined three- and
four-body features are found in the inelastic loss spectrum. Their relative
locations on either side of the resonance agree well with universal theory,
while a systematic deviation from universality is found when comparing features
across the resonance.Comment: 16 pages including figures and Supplementary Online Materia
Carbon Free Boston: Waste Technical Report
Part of a series of reports that includes:
Carbon Free Boston: Summary Report;
Carbon Free Boston: Social Equity Report;
Carbon Free Boston: Technical Summary;
Carbon Free Boston: Buildings Technical Report;
Carbon Free Boston: Transportation Technical Report;
Carbon Free Boston: Energy Technical Report;
Carbon Free Boston: Offsets Technical Report;
Available at http://sites.bu.edu/cfb/OVERVIEW:
For many people, their most perceptible interaction with their environmental footprint is through the
waste that they generate. On a daily basis people have numerous opportunities to decide whether to
recycle, compost or throwaway. In many cases, such options may not be present or apparent. Even
when such options are available, many lack the knowledge of how to correctly dispose of their waste,
leading to contamination of valuable recycling or compost streams. Once collected, people give little
thought to how their waste is treated. For Boston’s waste, plastic in the disposal stream acts becomes a
fossil fuel used to generate electricity. Organics in the waste stream have the potential to be used to
generate valuable renewable energy, while metals and electronics can be recycled to offset virgin
materials. However, challenges in global recycling markets are burdening municipalities, which are
experiencing higher costs to maintain their recycling.
The disposal of solid waste and wastewater both account for a large and visible anthropogenic impact
on human health and the environment. In terms of climate change, landfilling of solid waste and
wastewater treatment generated emissions of 131.5 Mt CO2e in 2016 or about two percent of total
United States GHG emissions that year. The combustion of solid waste contributed an additional 11.0 Mt
CO2e, over half of which (5.9 Mt CO2e) is attributable to the combustion of plastic [1]. In Massachusetts,
the GHG emissions from landfills (0.4 Mt CO2e), waste combustion (1.2 Mt CO2e), and wastewater (0.5
Mt CO2e) accounted for about 2.7 percent of the state’s gross GHG emissions in 2014 [2].
The City of Boston has begun exploring pathways to Zero Waste, a goal that seeks to systematically
redesign our waste management system that can simultaneously lead to a drastic reduction in emissions
from waste. The easiest way to achieve zero waste is to not generate it in the first place. This can start at
the source with the decision whether or not to consume a product. This is the intent behind banning
disposable items such as plastic bags that have more sustainable substitutes. When consumption occurs,
products must be designed in such a way that their lifecycle impacts and waste footprint are considered.
This includes making durable products, limiting the use of packaging or using organic packaging
materials, taking back goods at the end of their life, and designing products to ensure compatibility with
recycling systems. When reducing waste is unavoidable, efforts to increase recycling and organics
diversion becomes essential for achieving zero waste. [TRUNCATED]Published versio
Diurnal variations in optical depth at Mars: Observations and interpretations
Viking lander camera images of the Sun were used to compute atmospheric optical depth at two sites over a period of 1 to 1/3 martian years. The complete set of 1044 optical depth determinations is presented in graphical and tabular form. Error estimates are presented in detail. Optical depths in the morning (AM) are generally larger than in the afternoon (PM). The AM-PM differences are ascribed to condensation of water vapor into atmospheric ice aerosols at night and their evaporation in midday. A smoothed time series of these differences shows several seasonal peaks. These are simulated using a one-dimensional radiative convective model which predicts martial atmospheric temperature profiles. A calculation combining these profiles with water vapor measurements from the Mars Atmospheric Water Detector is used to predict when the diurnal variations of water condensation should occur. The model reproduces a majority of the observed peaks and shows the factors influencing the process. Diurnal variation of condensation is shown to peak when the latitude and season combine to warm the atmosphere to the optimum temperature, cool enough to condense vapor at night and warm enough to cause evaporation at midday
Using Kotter’s Eight Stage Process to Manage an Organisational Change Program: Presentation and Practice
© 2014, Springer Science+Business Media New York. Kotter’s eight stage process for creating a major change is one of the most widely recognised models for change management, and yet there are few case studies in the academic literature that enquire into how this process has been used in practice. This paper describes a change manager’s action research enquiring into the use of this Process to manage a major organisational change. The change was initiated in response to the organisation’s ageing workforce, introducing a knowledge management program focusing on the interpersonal aspects of knowledge retention. Although Kotter’s process emphasises a top-led model for change, the change team found it was necessary to engage at many levels of the organisation to implement the organisational change. The process is typically depicted as a linear sequence of steps. However, this image of the change process was found to not represent the complexity of the required action. Managing the change required the change team to facilitate multiple concurrent instances of Kotter’s process throughout the organisation, to re-create change that was locally relevant to participants in the change process
- …
