194 research outputs found
21 Layer troposphere-stratosphere climate model
The global climate model is extended through the stratosphere by increasing the vertical resolution and raising the rigid model top to the 0.01 mb (75 km) level. The inclusion of a realistic stratosphere is necessary for the investigation of the climate effects of stratospheric perturbations, such as changes of ozone, aerosols or solar ultraviolet irradiance, as well as for studying the effect on the stratosphere of tropospheric climate changes. The observed temperature and wind patterns throughout the troposphere and stratosphere are simulated. In addition to the excess planetary wave amplitude in the upper stratosphere, other model deficiences include the Northern Hemisphere lower stratospheric temperatures being 5 to 10 C too cold in winter at high latitudes and the temperature at 50 to 60 km altitude near the equator are too cold. Methods of correcting these deficiencies are discussed
Screening of patients for first time prostheses after amputation of lower limbs
In the world's developed countries, demographic changes, such as aging societies and increased numbers of diabetes patients, have led to an increase in amputations (11), and it is believed that as society ages, the number of people who are older than 65 will face as much as two times more amputations [3]. Of great importance after the amputation of a lower limb is the selection and adaptation of prostheses that allow patients to move around, thus achieving rehabilitation goals much more quickly [5]. A 20090-study of the rehabilitation of people with lower limb amputations in Latvia found that among 183 patients, 50% use their prostheses actively for more than 6 hours a day, 30% did not use them at all or used them for less than 3 hours a day, and 20% used them for 3-6 hours a day. The study included 173 patients with lower limb amputations who were evaluated in 2012 in relation with whether primary prosthesis should be provided. Of 173 patients who were evaluated, only 109 received a decision on primary prostheses, while in 51 cases the process was delayed for 1–3 months, in 12 cases, it was decided that prostheses would not be purposeful. More than 25% of those who followed the recommended treatment and rehabilitation programme to prepare the amputation stump, reduced contracture and enhanced physical working abilities were declared to be appropriate for further prostheses. This indicates serious shortcomings in medical treatments during the early post-amputation period.publishersversionPeer reviewe
Apple scab detection using CNN and Transfer Learning
Received: January 11th, 2021 ; Accepted: April 10th, 2021 ; Published: April 22nd, 2021 ; Correspondence: [email protected] goal of smart and precise horticulture is to increase yield and product quality by
simultaneous reduction of pesticide application, thereby promoting the improvement of food
security. The scope of this research is apple scab detection in the early stage of development using
mobile phones and artificial intelligence based on convolutional neural network (CNN)
applications. The research considers data acquisition and CNN training. Two datasets were
collected - with images of scab infected fruits and leaves of an apple tree. However, data
acquisition is a time-consuming process and scab appearance has a probability factor. Therefore,
transfer learning is an appropriate training methodology. The goal of this research was to select
the most suitable dataset for transfer learning for the apple scab detection domain and to evaluate
the transfer learning impact comparing it with learning from scratch. The statistical analysis
confirmed the positive effect of transfer learning on CNN performance with significance
level 0.05
Predictive use of the Maximum Entropy Production principle for Past and Present Climates
In this paper, we show how the MEP hypothesis may be used to build simple
climate models without representing explicitly the energy transport by the
atmosphere. The purpose is twofold. First, we assess the performance of the MEP
hypothesis by comparing a simple model with minimal input data to a complex,
state-of-the-art General Circulation Model. Next, we show how to improve the
realism of MEP climate models by including climate feedbacks, focusing on the
case of the water-vapour feedback. We also discuss the dependence of the
entropy production rate and predicted surface temperature on the resolution of
the model
EVALUATION OF GREEN LASER SOURCE ADDITIVE MANUFACTURING TECHNOLOGY FOR ACCELERATOR APPLICATIONS WITH ULTRA-HIGH VACUUM REQUIREMENTS
Additive Manufacturing (AM) offers different benefits such as efficient material usage, reduced production time and design freedom. Moreover, with continuous technological developments, AM expands in versatility and different material usage capabilities. Recently new energy sources have been developed for AM – green wavelength lasers, which provide better energy absorption for pure copper. Due to high thermal and electrical conductivity of copper, this novel AM technology is highly promising for various industries, particularly, there is a huge interest to use it for accelerator applications. In particular, these AM produced accelerator components should reach the associated Ultra High Vacuum (UHV)
requirements. In this study, vacuum membranes of pure copper were produced by AM using a green laser source, in different thicknesses and built angles. Furthermore, a vacuum membrane helium leak tightness test was performed at room temperature by using a high-sensitivity mass spectrometer. Comparison of these test results was performed with previously established results. Through this study, novel knowledge and initial results are provided
for green laser source AM technology usage for applications for UHV accelerator components
The GROUSE project II: Detection of the Ks-band secondary eclipse of exoplanet HAT-P-1b
Context: Only recently it has become possible to measure the thermal emission
from hot-Jupiters at near-Infrared wavelengths using ground-based telescopes,
by secondary eclipse observations. This allows the planet flux to be probed
around the peak of its spectral energy distribution, which is vital for the
understanding of its energy budget. Aims: The aim of the reported work is to
measure the eclipse depth of the planet HAT-P-1b at 2.2micron. This planet is
an interesting case, since the amount of stellar irradiation it receives falls
in between that of the two best studied systems (HD209458 and HD189733), and it
has been suggested to have a weak thermal inversion layer. Methods: We have
used the LIRIS instrument on the William Herschel Telescope (WHT) to observe
the secondary eclipse of HATP-1b in the Ks-band, as part of our Ground-based
secondary eclipse (GROUSE) project. The observations were done in staring mode,
while significantly defocusing the telescope to avoid saturation on the K=8.4
star. With an average cadence of 2.5 seconds, we collected 6520 frames during
one night. Results: The eclipse is detected at the 4sigma level, the measured
depth being 0.109+/-0.025%. The uncertainties are dominated by residual
systematic effects, as estimated from different reduction/analysis procedures.
The measured depth corresponds to a brightness temperature of 2136+150-170K.
This brightness temperature is significantly higher than those derived from
longer wavelengths, making it difficult to fit all available data points with a
plausible atmospheric model. However, it may be that we underestimate the true
uncertainties of our measurements, since it is notoriously difficult to assign
precise statistical significance to a result when systematic effects are
important.Comment: 7 pages, 10 figures, Accepted for publication in A&
Локальная система контроля и предупреждения аварийных ситуаций на хлороопасных предприятиях и объектах Украины
Розглянуто деякі питання вирішення проблеми контролю концентрації хлору в повітрі
робочої зони промислових підприємств та запропоновано створення системи контролю і
попередження аварійних ситуацій з використанням засобів газового аналізу.Some questions of the decision of a problem of the control of concentration of chlorine in air of a working zone of the industrial enterprises are considered. The recommendations for creation of the monitoring system and prevention of
emergencies with use of means of the gas
analysis are given.Рассмотрены некоторые вопросы решения
проблемы контроля концентрации хлора в
воздухе рабочей зоны промышленных предприятий. Даны рекомендации по созданию системы контроля и предупреждение аварийных ситуаций с использованием средств газового анализа
Global warming in the pipeline
Improved knowledge of glacial-to-interglacial global temperature change
implies that fast-feedback equilibrium climate sensitivity is at least
~4{\deg}C for doubled CO2 (2xCO2), with likely range 3.5-5.5{\deg}C. Greenhouse
gas (GHG) climate forcing is 4.1 W/m2 larger in 2021 than in 1750, equivalent
to 2xCO2 forcing. Global warming in the pipeline is greater than prior
estimates. Eventual global warming due to today's GHG forcing alone -- after
slow feedbacks operate -- is about 10{\deg}C. Human-made aerosols are a major
climate forcing, mainly via their effect on clouds. We infer from paleoclimate
data that aerosol cooling offset GHG warming for several millennia as
civilization developed. A hinge-point in global warming occurred in 1970 as
increased GHG warming outpaced aerosol cooling, leading to global warming of
0.18{\deg}C per decade. Aerosol cooling is larger than estimated in the current
IPCC report, but it has declined since 2010 because of aerosol reductions in
China and shipping. Without unprecedented global actions to reduce GHG growth,
2010 could be another hinge point, with global warming in following decades
50-100% greater than in the prior 40 years. The enormity of consequences of
warming in the pipeline demands a new approach addressing legacy and future
emissions. The essential requirement to "save" young people and future
generations is return to Holocene-level global temperature. Three urgently
required actions are: 1) a global increasing price on GHG emissions, 2)
purposeful intervention to rapidly phase down present massive geoengineering of
Earth's climate, and 3) renewed East-West cooperation in a way that
accommodates developing world needs.Comment: 48 pages, 27 figures. Correction of formatting error on page 21,
which messed up placement of all following figure
A novel satellite mission concept for upper air water vapour, aerosol and cloud observations using integrated path differential absorption LiDAR limb sounding
We propose a new satellite mission to deliver high quality measurements of upper air water vapour. The concept centres around a LiDAR in limb sounding by occultation geometry, designed to operate as a very long path system for differential absorption measurements. We present a preliminary performance analysis with a system sized to send 75 mJ pulses at 25 Hz at four wavelengths close to 935 nm, to up to 5 microsatellites in a counter-rotating orbit, carrying retroreflectors characterized by a reflected beam divergence of roughly twice the emitted laser beam divergence of 15 µrad. This provides water vapour profiles with a vertical sampling of 110 m; preliminary calculations suggest that the system could detect concentrations of less than 5 ppm. A secondary payload of a fairly conventional medium resolution multispectral radiometer allows wide-swath cloud and aerosol imaging. The total weight and power of the system are estimated at 3 tons and 2,700 W respectively. This novel concept presents significant challenges, including the performance of the lasers in space, the tracking between the main spacecraft and the retroreflectors, the refractive effects of turbulence, and the design of the telescopes to achieve a high signal-to-noise ratio for the high precision measurements. The mission concept was conceived at the Alpbach Summer School 2010
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