153 research outputs found
Major factors influencing local dust radiative forcing
No full textIn conclusion, it is shown in this paper that surface albedo variations over desert regions can have a significant influence on the solar and net radiative forcing of desert dust. It is furthermore concluded that desert dust has mostly a cooling effect over oceans, and a warming effect over highly reflecting desert regions. The widespread non-sphericity of the dust particles causes a challenge; it yields an additional contribution to the cooling effect. It is also concluded here that it might be more appropriate not to start with microphysical properties in order to quantify the dust particle radiative effects. Direct measurements of the optical dust particle properties are preferable, otherwise too much uncertainties are coming into play (shape, composition, size). Using the microphysical properties is more suited if the sensitivity of the radiative forcing is investigated
Dust mobilization and transport in the northern Sahara during SAMUM 2006 � a meteorological overview
No full textThe SAMUM field campaign in southern Morocco in May/June 2006 provides valuable data to study the emission, and the horizontal and vertical transports of mineral dust in the Northern Sahara. Radiosonde and lidar observations show differential advection of air masses with different characteristics during stable nighttime conditions and up to 5-km deep vertical mixing in the strongly convective boundary layer during the day. Lagrangian and synoptic analyses of selected
dust periods point to a topographic channel from western Tunisia to central Algeria as a dust source region. Significant emission events are related to cold surges from the Mediterranean in association with eastward passing upper-level waves and lee cyclogeneses south of the Atlas Mountains. Other relevant events are local emissions under a distinct
cut-off low over northwestern Africa and gust fronts associated with dry thunderstorms over the Malian and Algerian Sahara. The latter are badly represented in analyses from the European Centre for Medium�Range Weather Forecasts and in a regional dust model, most likely due to problems with moist convective dynamics and a lack of observations in this region. This aspect needs further study. The meteorological source identification is consistent with estimates of optical and mineralogical properties of dust samples
Cultural Particularities and Its Role in the “Innovation Divide”: A Closer Look at the Origins of “Spreading Excellence and Widening Participation”
No full textPublisher Copyright: © 2023, The Author(s).The “innovation divide” has been a common and persistent problem since the onset of Framework Programmes for Research and Innovation. Especially, for the group of countries that joined the European Union after 2004. Several initiatives have been implemented by the Union for encouraging the participation of these countries in these collaborative programmes, trying to maximize and extend the benefits of a knowledge economy across the EU. In this chapter, we explore how these instruments have been deployed paying special attention to the origins of “Spreading Excellence and Widening Participation” Horizon 2020 Work Programme. We explore its objectives and rationale, and we address some of its weaknesses and pitfalls. We argue that the “innovation divide” is not only a matter of providing adequate resources and encouraging participation for these countries and they cannot be treated as a homogeneous group. Particularly, in a moment of transition regarding innovation policies.Peer reviewe
Mixed-method research to foster energy efficiency investments by small private landlords in Germany
No full textThe decarbonisation of the building stock is an important element for the success of the German Energiewende (energy transition). Despite some progress having been made, the rate of energy renovation falls below the level required to meet political commitments. This gives rise to the question: what deters property owners from making energy efficiency investments and how can the policy framework foster such investments? To answer this question, the paper focuses on a widely neglected property owner group: small private landlords (SPL). Although they manage 37% of all residential rental properties in Germany, very little is known about their decision-making processes for energy efficiency investments. We applied a mixed-method design to identify factors that hindered and supported their investments. In an explorative study, we initially conducted 18 problem-centred interviews. Subsequently, we carried out a postal survey and analysed the questionnaires using a hierarchical linear regression model. The results show that energy renovation is a multi-dimensional decision-making process, which can only be adequately addressed by a comprehensive policy package. To develop such a package, the author recommends that the specific investment behaviour of SPL must be better targeted, their knowledge about energy efficiency investments must be improved through exchange and networking, a sense of responsibility for the neighbourhood must be fostered, and greater focus must be placed on improving local framework condition
Airborne observations and simulations of three-dimensional radiative interactions between Arctic boundary layer clouds and ice floes
No full textBased on airborne spectral imaging observations, three-dimensional
(3-D) radiative effects between Arctic boundary layer clouds and highly variable Arctic
surfaces were identified and quantified. A method is presented to
discriminate between sea ice and open water under cloudy conditions based on airborne nadir reflectivity γλ
measurements in the visible spectral range.
In cloudy cases the transition of γλ from open water to
sea ice is not instantaneous but horizontally smoothed. In
general, clouds reduce γλ above bright surfaces in
the vicinity of open water, while
γλ above open sea is enhanced. With the help of
observations and 3-D radiative transfer simulations, this effect
was quantified to range between 0 and 2200 m distance to the sea ice edge
(for a dark-ocean albedo of αwater = 0.042
and a sea-ice albedo of αice = 0.91 at 645 nm wavelength). The affected distance Δ L was found to depend
on both cloud and sea ice properties. For a low-level cloud
at 0–200 m altitude, as observed during the Arctic field
campaign VERtical Distribution of Ice in Arctic clouds (VERDI) in 2012,
an increase in the cloud optical thickness τ
from 1 to 10 leads to a decrease in Δ L from 600 to
250 m. An increase in the cloud base altitude or cloud
geometrical thickness results in an increase in Δ L;
for τ = 1/10 Δ L = 2200 m/1250 m in case of a cloud at
500–1000 m altitude. To quantify the effect for
different shapes and sizes of ice floes, radiative transfer simulations were performed with various albedo fields
(infinitely long straight ice edge, circular ice floes, squares, realistic ice floe
field). The simulations show that Δ L increases with
increasing radius of the ice floe and reaches maximum values for ice floes with radii larger than 6 km
(500–1000 m cloud altitude), which matches the results found for an infinitely long, straight ice edge.
Furthermore, the influence of these 3-D radiative effects on the retrieved
cloud optical properties was investigated. The enhanced
brightness of a dark pixel next to an ice edge results in
uncertainties of up to 90 and 30 % in retrievals of τ
and effective radius reff, respectively.
With the help of Δ L, an estimate of the distance to the ice
edge is given, where the retrieval uncertainties due to 3-D radiative effects are negligible
A Simulation based model for the berth allocation and quay crane assignment problem
No full textWith the global development of container transport, container terminals have become important nodes in transport networks which serve as hubs for the transshipment of containerized goods from ship to ship or from ship to other transport modes. As the container transport system is capital intensive, the turnaround time of ships at container terminals is an important factor for liner shipping companies to consider in order to decrease their costs. The turnaround time includes berthing, unloading, loading and departure and therefore, berth allocation and quay cranes assignment for unloading and loading operations is critical to the efficiency of container terminal systems. In addition, the rising competition between ports has compelled them to improve their service levels with the efficiency of container terminal operations becoming an important factor for success (Zeng, 2009)
Erste Erfahrungen mit Sitagliptin als Zusatz zu Insulin in diabetologischen Schwerpunktpraxen
No full textThe Effects of Visuospatial Environment on Endurance Treadmill Running Performance, RPE, and Heart Rate
No full textThe psychobiological model of endurance exercise suggests that endurance exercise performance is determined primarily by perception of effort. Previous research has shown that inducing mental and physical fatigue affects rating of perceived exertion (RPE), ultimately affecting endurance performance. However, there is limited literature describing the effect of visual stimuli on RPE. In particular, effects of visuospatial environment, one that elicits thought processes involving visual and spatial awareness, have not been investigated. PURPOSE: The purpose of this study was to investigate the effect of visuospatial environment on endurance exercise performance, RPE, and heart rate (HR). METHODS: 22 participants completed a self-paced 20-minute treadmill run in an open visuospatial environment (treadmill in front of an open window) and a closed visuospatial environment (treadmill surrounded by privacy curtains). A randomized cross-over design was used and each participant experienced each condition. The main outcome measures were total distance covered during the 20-minute trial and RPE, which was measured every 2 minutes. Additionally, HR was recorded throughout the trial. RESULTS: Total distance traveled was similar between groups (3.49 (0.51) km and 3.44 (0.60) km for open and closed conditions, respectively) with no differences between groups in RPE or HR (p \u3e 0.05). This suggests that open and closed visuospatial environments are not influencing factors on endurance performance, RPE, and HR. Further research is required to investigate other factors that contribute to perceived effort during endurance exercise. CONCLUSION: Results suggest that visuospatial environment has no effect on perception or performance during endurance exercise on a motorized treadmill . Future studies should consider using a non-motorized endurance test, such as a stationary bike or non-motorized treadmill. Additionally, unwanted visual stimuli should be limited
Webs of Innovation and Value Chains of Additive Manufacturing under Concideration of RRI: D2.1 Literature review
No full textFour extensive literature reviews on factors for innovation success in terms of market, strategic and social impact for additive manufacturing were performed where the focus lies on three levels of analysis; (inter)organizational, business model, and project.I AM RRI Identifier: IAMRRI_D2_1_V2_Final Version date: 14.03.2019 Work package: WP2Economics of Technology and Innovatio
Combined retrieval of Arctic liquid water cloud and surface snow properties using airborne spectral solar remote sensing
No full textThe passive solar remote sensing of cloud properties over highly
reflecting ground is challenging, mostly due to the low contrast
between the cloud reflectivity and that of the underlying
surfaces (sea ice and snow). Uncertainties in the retrieved
cloud optical thickness τ and cloud droplet effective
radius reff, C may arise from uncertainties in the
assumed spectral surface albedo, which is mainly determined by
the generally unknown effective snow grain size reff, S.
Therefore, in a first step the effects of the assumed snow grain
size are systematically quantified for the conventional
bispectral retrieval technique of τ and reff, C
for liquid water clouds. In general, the impact of uncertainties
of reff, S is largest for small snow grain sizes. While
the uncertainties of retrieved τ are independent of the
cloud optical thickness and solar zenith angle, the bias of
retrieved reff, C increases for optically thin clouds
and high Sun. The largest deviations between the retrieved and
true original values are found with 83 % for τ and 62 %
for reff, C.In the second part of the paper a retrieval method is presented that
simultaneously derives all three parameters (τ, reff, C, reff, S) and therefore accounts for changes
in the snow grain size. Ratios of spectral cloud
reflectivity measurements at the three wavelengths
λ1 = 1040 nm (sensitive to reff, S),
λ2 = 1650 nm (sensitive to τ), and
λ3 = 2100 nm (sensitive to reff, C) are
combined in a trispectral retrieval algorithm. In a feasibility
study, spectral cloud reflectivity measurements collected by the
Spectral Modular Airborne Radiation measurement sysTem (SMART)
during the research campaign Vertical Distribution of Ice in
Arctic Mixed-Phase Clouds (VERDI, April/May 2012) were used to
test the retrieval procedure. Two cases of observations above
the Canadian Beaufort Sea, one with dense snow-covered sea ice
and another with a distinct snow-covered sea ice edge are
analysed. The retrieved values of τ, reff, C, and
reff, S show a continuous transition of cloud properties
across snow-covered sea ice and open water and are consistent
with estimates based on satellite data. It is shown that the
uncertainties of the trispectral retrieval increase for high
values of τ, and low reff, S but nevertheless allow
the effective snow grain size in cloud-covered areas to be estimated
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