Showing papers by "Leibniz University of Hanover published in 2015"
07 Jun 2015
TL;DR: A novel model and dataset for 3D scene flow estimation with an application to autonomous driving by representing each element in the scene by its rigid motion parameters and each superpixel by a 3D plane as well as an index to the corresponding object.
Abstract: This paper proposes a novel model and dataset for 3D scene flow estimation with an application to autonomous driving. Taking advantage of the fact that outdoor scenes often decompose into a small number of independently moving objects, we represent each element in the scene by its rigid motion parameters and each superpixel by a 3D plane as well as an index to the corresponding object. This minimal representation increases robustness and leads to a discrete-continuous CRF where the data term decomposes into pairwise potentials between superpixels and objects. Moreover, our model intrinsically segments the scene into its constituting dynamic components. We demonstrate the performance of our model on existing benchmarks as well as a novel realistic dataset with scene flow ground truth. We obtain this dataset by annotating 400 dynamic scenes from the KITTI raw data collection using detailed 3D CAD models for all vehicles in motion. Our experiments also reveal novel challenges which cannot be handled by existing methods.
1,918 citations
TL;DR: In this article, the authors review the spectacular accuracy and stability gains that can be obtained when working with laser cooled ions or neutral atoms and discuss some important applications of these optical clocks, from geodesy to tests of fundamental theories to many body physics.
Abstract: Since 1967 the primary time standard is the cesium atomic clock, based on a hyperfine transition in the microwave domain The development of ultrastable laser sources now allows one to operate on electronic transitions in the optical domain, corresponding to a 5-order-of-magnitude increase in the clock frequency This article reviews the spectacular accuracy and stability gains that can be obtained when working with laser cooled ions or neutral atoms It also discusses some important applications of these optical clocks, from geodesy to tests of fundamental theories to many-body physics
1,393 citations
TL;DR: In this paper, the authors review the performance of the LIGO instruments during this epoch, the work done to characterize the detectors and their data, and the effect that transient and continuous noise artefacts have on the sensitivity of the detectors to a variety of astrophysical sources.
Abstract: In 2009–2010, the Laser Interferometer Gravitational-Wave Observatory (LIGO) operated together with international partners Virgo and GEO600 as a network to search for gravitational waves (GWs) of astrophysical origin. The sensitivity of these detectors was limited by a combination of noise sources inherent to the instrumental design and its environment, often localized in time or frequency, that couple into the GW readout. Here we review the performance of the LIGO instruments during this epoch, the work done to characterize the detectors and their data, and the effect that transient and continuous noise artefacts have on the sensitivity of LIGO to a variety of astrophysical sources.
1,266 citations
TL;DR: The state of the art in continuum robot manipulators and systems intended for application to interventional medicine are described, and relevant research in design, modeling, control, and sensing for continuum manipulators are discussed.
Abstract: In this paper, we describe the state of the art in continuum robot manipulators and systems intended for application to interventional medicine. Inspired by biological trunks, tentacles, and snakes, continuum robot designs can traverse confined spaces, manipulate objects in complex environments, and conform to curvilinear paths in space. In addition, many designs offer inherent structural compliance and ease of miniaturization. After decades of pioneering research, a host of designs have now been investigated and have demonstrated capabilities beyond the scope of conventional rigid-link robots. Recently, we have seen increasing efforts aimed at leveraging these qualities to improve the frontiers of minimally invasive surgical interventions. Several concepts have now been commercialized, which are inspiring and enabling a current paradigm shift in surgical approaches toward flexible access routes, e.g., through natural orifices such as the nose. In this paper, we provide an overview of the current state of this field from the perspectives of both robotics science and medical applications. We discuss relevant research in design, modeling, control, and sensing for continuum manipulators, and we highlight how this work is being used to build robotic systems for specific surgical procedures. We provide perspective for the future by discussing current limitations, open questions, and challenges.
986 citations
TL;DR: In this article, advances in the strategies for the visible light activation, origin of visible light activity, and electronic structure of various visible-light active TiO 2 photocatalysts are discussed in detail.
Abstract: The remarkable achievement by Fujishima and Honda (1972) in the photo-electrochemical water splitting results in the extensive use of TiO 2 nanomaterials for environmental purification and energy storage/conversion applications. Though there are many advantages for the TiO 2 compared to other semiconductor photocatalysts, its band gap of 3.2 eV restrains application to the UV-region of the electromagnetic spectrum ( λ ≤ 387.5 nm). As a result, development of visible-light active titanium dioxide is one of the key challenges in the field of semiconductor photocatalysis. In this review, advances in the strategies for the visible light activation, origin of visible-light activity, and electronic structure of various visible-light active TiO 2 photocatalysts are discussed in detail. It has also been shown that if appropriate models are used, the theoretical insights can successfully be employed to develop novel catalysts to enhance the photocatalytic performance in the visible region. Recent developments in theory and experiments in visible-light induced water splitting, degradation of environmental pollutants, water and air purification and antibacterial applications are also reviewed. Various strategies to identify appropriate dopants for improved visible-light absorption and electron–hole separation to enhance the photocatalytic activity are discussed in detail, and a number of recommendations are also presented.
921 citations
TL;DR: To improve ingrowth of blood vessels into porous implants, proangiogenic factors like Vascular Endothelial Growth Factor (VEGF) and High Mobility Group Box 1 (HMGB1) were incorporated into PCL coated, porous titanium and magnesium implants.
Abstract: For healing of critically sized bone defects, biocompatible and angiogenesis supporting implants are favorable. Murine osteoblasts showed equal proliferation behavior on the polymers poly-e-caprolactone (PCL) and poly-(3-hydroxybutyrate)/poly-(4-hydroxybutyrate) (P(3HB)/P(4HB)). As vitality was significantly better for PCL, it was chosen as a suitable coating material for further experiments. Titanium implants with 600 µm pore size were evaluated and found to be a good implant material for bone, as primary osteoblasts showed a vitality and proliferation onto the implants comparable to well bottom (WB). Pure porous titanium implants and PCL coated porous titanium implants were compared using Live Cell Imaging (LCI) with Green fluorescent protein (GFP)-osteoblasts. Cell count and cell covered area did not differ between the implants after seven days. To improve ingrowth of blood vessels into porous implants, proangiogenic factors like Vascular Endothelial Growth Factor (VEGF) and High Mobility Group Box 1 (HMGB1) were incorporated into PCL coated, porous titanium and magnesium implants. An angiogenesis assay was performed to establish an in vitro method for evaluating the impact of metallic implants on angiogenesis to reduce and refine animal experiments in future. Incorporated concentrations of proangiogenic factors were probably too low, as they did not lead to any effect. Magnesium implants did not yield evaluable results, as they led to pH increase and subsequent cell death.
883 citations
TL;DR: An overview of the current knowledge on mineral-organic associations can be found in this article, where the authors identify key questions and future research needs, as well as a survey of the existing research work.
Abstract: Minerals and organic matter (OM) may form intricate associations via myriad interactions. In soils, the associations of OM with mineral surfaces are mainly investigated because of their role in determining the long-term retention of OM. OM “must decay in order to release the energy and nutrients that drive live processes all over the planet” ( Janzen, 2006 ). Thus, the processes and mechanisms that retain OM in soil are a central concern to very different branches of environmental research. An agronomist may want to synchronize periods of high nutrient and energy release with the growth stages of a crop. An environmental chemist may wish to either immobilize an organic soil contaminant or enhance its decomposition into less harmful metabolites, while climate scientists need to understand the processes that mediate the production of potent greenhouse gases from decomposing OM. Associations of OM with pedogenic minerals (henceforth termed mineral–organic associations (MOAs)) are known to be key controls in these and many other processes. Here we strive to present an overview of the current knowledge on MOAs and identify key questions and future research needs.
818 citations
TL;DR: The biological role of amino acid catabolism is discussed, current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology is summarized and current knowledge about building blocks for several biosynthesis pathways is summarized.
749 citations
TL;DR: The field of metal–organic framework based mixed matrix membranes (M4s) is critically reviewed, with special emphasis on their application in CO2 capture during energy generation.
Abstract: The field of metal–organic framework based mixed matrix membranes (M4s) is critically reviewed, with special emphasis on their application in CO2 capture during energy generation. After introducing the most relevant parameters affecting membrane performance, we define targets in terms of selectivity and productivity based on existing literature on process design for pre- and post-combustion CO2 capture. Subsequently, the state of the art in M4s is reviewed against these targets. Because final application of these membranes will only be possible if thin separation layers can be produced, the latest advances in the manufacture of M4 hollow fibers are discussed. Finally, the recent efforts in understanding the separation performance of these complex composite materials and future research directions are outlined.
673 citations
TL;DR: This work proposes the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard, to facilitate consistent and systematic deposition and retrieval of data on biosynthetic gene clusters.
Abstract: A wide variety of enzymatic pathways that produce specialized metabolites in bacteria, fungi and plants are known to be encoded in biosynthetic gene clusters. Information about these clusters, pathways and metabolites is currently dispersed throughout the literature, making it difficult to exploit. To facilitate consistent and systematic deposition and retrieval of data on biosynthetic gene clusters, we propose the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard.
633 citations
TL;DR: The latest developments in zeolite membranes are reviewed, with an emphasis on the synthesis techniques, including seed assembly and secondary growth methods, and the latest advancements in MOF and mixed matrix membranes are highlighted.
Abstract: The latest developments in zeolite membranes are reviewed, with an emphasis on the synthesis techniques, including seed assembly and secondary growth methods. This review also discusses the current industrial applications of zeolite membranes, the feasibility of their use in membrane reactors and their hydrothermal stability. Finally, zeolite membranes are compared with metal–organic framework (MOF) membranes and the latest advancements in MOF and mixed matrix membranes are highlighted.
TL;DR: A detailed description of the current version of the Parallelized Large-Eddy Simulation Model (PALM) and its features, such as an embedded Lagrangian cloud model and the possibility to use Cartesian topography are given.
Abstract: . In this paper we present the current version of the Parallelized Large-Eddy Simulation Model (PALM) whose core has been developed at the Institute of Meteorology and Climatology at Leibniz Universitat Hannover (Germany). PALM is a Fortran 95-based code with some Fortran 2003 extensions and has been applied for the simulation of a variety of atmospheric and oceanic boundary layers for more than 15 years. PALM is optimized for use on massively parallel computer architectures and was recently ported to general-purpose graphics processing units. In the present paper we give a detailed description of the current version of the model and its features, such as an embedded Lagrangian cloud model and the possibility to use Cartesian topography. Moreover, we discuss recent model developments and future perspectives for LES applications.
TL;DR: In this article, the uncertainty of the band-to-band absorption coefficient of crystalline silicon was analyzed using the Guide to the expression of uncertainty in measurement (GUM) as well as an extensive characterization of the measurement setups.
Abstract: We analyze the uncertainty of the coefficient of band-to-band absorption of crystalline silicon. For this purpose, we determine the absorption coefficient at room temperature (295 K) in the wavelength range from 250 to 1450 nm using four different measurement methods. The data presented in this work derive from spectroscopic ellipsometry, measurements of reflectance and transmittance, spectrally resolved luminescence measurements and spectral responsivity measurements. A systematic measurement uncertainty analysis based on the Guide to the expression of uncertainty in measurement (GUM) as well as an extensive characterization of the measurement setups are carried out for all methods. We determine relative uncertainties of the absorption coefficient of 0.4% at 250 nm, 11% at 600 nm, 1.4% at 1000 nm, 12% at 1200 nm and 180% at 1450 nm. The data are consolidated by intercomparison of results obtained at different institutions and using different measurement approaches.
TL;DR: This review revisits and discusses various correction factors which are mandatory for an accurate derivation of the resistivity from the measured resistance, including sample thickness, dimensionality, anisotropy, and the relative size and geometry of the sample with respect to the contact assembly.
Abstract: The electrical conductivity of solid-state matter is a fundamental physical property and can be precisely derived from the resistance measured via the four-point probe technique excluding contributions from parasitic contact resistances. Over time, this method has become an interdisciplinary characterization tool in materials science, semiconductor industries, geology, physics, etc, and is employed for both fundamental and application-driven research. However, the correct derivation of the conductivity is a demanding task which faces several difficulties, e.g. the homogeneity of the sample or the isotropy of the phases. In addition, these sample-specific characteristics are intimately related to technical constraints such as the probe geometry and size of the sample. In particular, the latter is of importance for nanostructures which can now be probed technically on very small length scales. On the occasion of the 100th anniversary of the four-point probe technique, introduced by Frank Wenner, in this review we revisit and discuss various correction factors which are mandatory for an accurate derivation of the resistivity from the measured resistance. Among others, sample thickness, dimensionality, anisotropy, and the relative size and geometry of the sample with respect to the contact assembly are considered. We are also able to derive the correction factors for 2D anisotropic systems on circular finite areas with variable probe spacings. All these aspects are illustrated by state-of-the-art experiments carried out using a four-tip STM/SEM system. We are aware that this review article can only cover some of the most important topics. Regarding further aspects, e.g. technical realizations, the influence of inhomogeneities or different transport regimes, etc, we refer to other review articles in this field.
TL;DR: A novel unified approach which reasons jointly about 3D scene flow as well as the pose, shape and motion of vehicles in the scene is proposed and the results provide a prove of concept and demonstrate the usefulness of the method.
Abstract: . driving. While much progress has been made in recent years, imaging conditions in natural outdoor environments are still very challenging for current reconstruction and recognition methods. In this paper, we propose a novel unified approach which reasons jointly about 3D scene flow as well as the pose, shape and motion of vehicles in the scene. Towards this goal, we incorporate a deformable CAD model into a slanted-plane conditional random field for scene flow estimation and enforce shape consistency between the rendered 3D models and the parameters of all superpixels in the image. The association of superpixels to objects is established by an index variable which implicitly enables model selection. We evaluate our approach on the challenging KITTI scene flow dataset in terms of object and scene flow estimation. Our results provide a prove of concept and demonstrate the usefulness of our method.
TL;DR: It is demonstrated that the sol–gel process represents a powerful “bottom-up” strategy for creating nanostructured materials that tackles the problems of high cost, insufficient activity, and inadequate long-term durability of metal aerogels.
Abstract: ConspectusMetallic and catalytically active materials with high surface area and large porosity are a long-desired goal in both industry and academia. In this Account, we summarize the strategies for making a variety of self-supported noble metal aerogels consisting of extended metal backbone nanonetworks. We discuss their outstanding physical and chemical properties, including their three-dimensional network structure, the simple control over their composition, their large specific surface area, and their hierarchical porosity. Additionally, we show some initial results on their excellent performance as electrocatalysts combining both high catalytic activity and high durability for fuel cell reactions such as ethanol oxidation and the oxygen reduction reaction (ORR). Finally, we give some hints on the future challenges in the research area of metal aerogels. We believe that metal aerogels are a new, promising class of electrocatalysts for polymer electrolyte fuel cells (PEFCs) and will also open great op...
18 Apr 2015
TL;DR: The prevalent malicious activity on crowdsourcing platforms is analyzed and different types of workers in the crowd are defined, a method to measure malicious activity is proposed, and guidelines for the efficient design of crowdsourced surveys are presented.
Abstract: Crowdsourcing is increasingly being used as a means to tackle problems requiring human intelligence. With the ever-growing worker base that aims to complete microtasks on crowdsourcing platforms in exchange for financial gains, there is a need for stringent mechanisms to prevent exploitation of deployed tasks. Quality control mechanisms need to accommodate a diverse pool of workers, exhibiting a wide range of behavior. A pivotal step towards fraud-proof task design is understanding the behavioral patterns of microtask workers. In this paper, we analyze the prevalent malicious activity on crowdsourcing platforms and study the behavior exhibited by trustworthy and untrustworthy workers, particularly on crowdsourced surveys. Based on our analysis of the typical malicious activity, we define and identify different types of workers in the crowd, propose a method to measure malicious activity, and finally present guidelines for the efficient design of crowdsourced surveys.
TL;DR: The implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light and is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector.
Abstract: When quantum key distribution is composed with other secure protocols the overall security has to be guaranteed, which adds further security requirements. Here, the authors demonstrate continuous-variable quantum key distribution with composable security and one-sided-device independence.
TL;DR: The authors present their recent work in this field, ranging from sensor systems fabricated on traditional substrate materials like silicon (Si), over new fabrication techniques for magnetoresistive sensors on flexible substrates for special applications, e.g., a flexible write head for component integrated data storage.
Abstract: The research and development in the field of magnetoresistive sensors has played an important role in the last few decades. Here, the authors give an introduction to the fundamentals of the anisotropic magnetoresistive (AMR) and the giant magnetoresistive (GMR) effect as well as an overview of various types of sensors in industrial applications. In addition, the authors present their recent work in this field, ranging from sensor systems fabricated on traditional substrate materials like silicon (Si), over new fabrication techniques for magnetoresistive sensors on flexible substrates for special applications, e.g., a flexible write head for component integrated data storage, micro-stamping of sensors on arbitrary surfaces or three dimensional sensing under extreme conditions (restricted mounting space in motor air gap, high temperatures during geothermal drilling).
TL;DR: The simple homogeneous reaction S → P is considered and the rate equations for the thermal and photochemical version are compared and the first order rate constant is obtained.
Abstract: Quantum Yields? P constitutes the most promising method for the chemical utilization of solar energy. It is based on homogeneous or heterogeneous photocatalysts enabling electron transfer reactions with various organic and inorganic compounds. Typical examples are dissolved transition metal complexes, suspended semiconductor powders, and thin films in contact with gaseous or dissolved substrates. When comparing the reactivity (activity) of various photocatalysts very often rate constants are reported in the literature, as usually done in thermal chemistry. This is not justified for any photoreaction, irrespective of whether homoor heterogeneous, stoichiometric or catalytic. Therefore, most of previously reported comparisons have to be taken with care. In the following, we briefly summarize why only quantum yields and not rate constants can be compared. We consider the simple homogeneous reaction S → P and compare the rate equations for the thermal and photochemical version. In the thermal reaction, the disappearance rate of S is given by eq 1, which affords the final expression (eq 3) after rearrangement to eq 2 and integration. From the slope of the corresponding linear plot the first order rate constant is obtained.
TL;DR: The most important mycotoxins with phytotoxic effects and their producers in addition to their discovery are briefly outlined below and will be addressed in this article.
Abstract: Mycotoxins are secondary fungal metabolites, toxic to humans, animals and plants. Among the hundreds of known mycotoxins, aflatoxins, citrinin, patulin, penicillic acid, tenuazonic acid, ochratoxin A, cytochalasins, deoxynivalenol, fumonisins, fusarin C, fusaric acid, and zearalenone are considered the types that most contaminate cereal grain. The majority of the mycotoxins in these groups are produced by three fungal genera: Aspergillus, Penicillium and Fusarium. These metabolites primarily affect the seed quality, germination, viability, seedling vigour, growth of root and cleoptile. Additionally, since the fungi responsible for the production of these mycotoxins are often endophytes that infect and colonize living plant tissues, accumulation of mycotoxins in the plant tissues may at times be associated with development of plant disease symptoms. The presence of mycotoxins, even in the absence of disease symptoms, may still have subtle biological effects on the physiology of plants. Several studies highlight the toxic effects of mycotoxins on animals and cell lines but little is known about the mode of action of most of these metabolites on plant cells. The most important mycotoxins with phytotoxic effects and their producers in addition to their discovery are briefly outlined below and will be addressed in this article.
TL;DR: This work reports on the deterministic preparation of antiferromagnetic Heisenberg spin chains consisting of up to four fermionic atoms in a one-dimensional trap that are stabilized by strong repulsive interactions between the two spin components without the need for an external periodic potential.
Abstract: We report on the deterministic preparation of antiferromagnetic Heisenberg spin chains consisting of up to four fermionic atoms in a one-dimensional trap. These chains are stabilized by strong repulsive interactions between the two spin components without the need for an external periodic potential. We independently characterize the spin configuration of the chains by measuring the spin orientation of the outermost particle in the trap and by projecting the spatial wave function of one spin component on single-particle trap levels. Our results are in good agreement with a spin-chain model for fermionized particles and with numerically exact diagonalizations of the full few-fermion system.
University of South Carolina1, Embry–Riddle Aeronautical University2, Institut d'Astrophysique de Paris3, University of Birmingham4, University of Bordeaux5, European Space Agency6, University of Naples Federico II7, Leibniz University of Hanover8, Sapienza University of Rome9, University of Zurich10, Centre national de la recherche scientifique11, University of Düsseldorf12, University of Florence13, German National Metrology Institute14, Carleton College15
TL;DR: The STE-QUEST science case as mentioned in this paper describes the scientific objectives in fundamental physics of the Space-Time Explorer (STE-QUEST), which carries out tests of different aspects of the Einstein equivalence principle using atomic clocks, matter wave interferometry and long distance time/frequency links.
TL;DR: In this paper, the geochemistry of magnetite from the Cretaceous Kiruna-type Los Colorados IOA deposit in Chile has been studied using laser ablation-inductively coupled plasma mass spectroscopy (LA-ICP-MS) transects and electron probe micro-analyzer (EPMA) wavelength-dispersive X-ray (WDX) spectrometry mapping.
University of Western Australia1, Chinese Academy of Sciences2, Shanxi University3, Zhejiang University4, Beijing Normal University5, California Institute of Technology6, University of Florida7, West Virginia University8, Commonwealth Scientific and Industrial Research Organisation9, Curtin University10, International School for Advanced Studies11, Henan University12, Capital Normal University13, Max Planck Society14, Leibniz University of Hanover15
TL;DR: In the centenary year of Einstein's General Theory of Relativity, the authors reviewed the current status of gravitational wave astronomy across a spectrum which stretches from attohertz to kilo-hertz frequencies.
Abstract: In the centenary year of Einstein’s General Theory of Relativity, this paper reviews the current status of gravitational wave astronomy across a spectrum which stretches from attohertz to kilohertz frequencies. Sect. 1 of this paper reviews the historical development of gravitational wave astronomy from Einstein’s first prediction to our current understanding the spectrum. It is shown that detection of signals in the audio frequency spectrum can be expected very soon, and that a north-south pair of next generation detectors would provide large scientific benefits. Sect. 2 reviews the theory of gravitational waves and the principles of detection using laser interferometry. The state of the art Advanced LIGO detectors are then described. These detectors have a high chance of detecting the first events in the near future. Sect. 3 reviews the KAGRA detector currently under development in Japan, which will be the first laser interferometer detector to use cryogenic test masses. Sect. 4 of this paper reviews gravitational wave detection in the nanohertz frequency band using the technique of pulsar timing. Sect. 5 reviews the status of gravitational wave detection in the attohertz frequency band, detectable in the polarisation of the cosmic microwave background, and discusses the prospects for detection of primordial waves from the big bang. The techniques described in sects. 1–5 have already placed significant limits on the strength of gravitational wave sources. Sects. 6 and 7 review ambitious plans for future space based gravitational wave detectors in the millihertz frequency band. Sect. 6 presents a roadmap for development of space based gravitational wave detectors by China while sect. 7 discusses a key enabling technology for space interferometry known as time delay interferometry.
TL;DR: In this article, the authors investigated the interaction of migration, vulnerability to poverty, and welfare of rural households in three provinces in Central Vietnam and found that migration, especially migration for employment, is a livelihood support strategy for households exposed to agricultural and economic shocks.
TL;DR: An intuitive approach to the stochastic network calculus is contributed, where the method uses moment generating functions, known from the theory of effective bandwidths, to characterize traffic arrivals and network service.
Abstract: The aim of the stochastic network calculus is to comprehend statistical multiplexing and scheduling of non-trivial traffic sources in a framework for end-to-end analysis of multi-node networks. To date, several models, some of them with subtle yet important differences, have been explored to achieve these objectives. Capitalizing on previous works, this paper contributes an intuitive approach to the stochastic network calculus, where we seek to obtain its fundamental results in the possibly easiest way. In detail, the method that is assembled in this work uses moment generating functions, known from the theory of effective bandwidths, to characterize traffic arrivals and network service. Thereof, affine envelope functions with an exponentially decaying overflow profile are derived to compute statistical end-to-end backlog and delay bounds for networks.
TL;DR: The current state of the art in terms of HPP microbial inactivation mechanisms in model systems and various low aw food environments is assessed with an emphasis on mechanisms of inactivation and treatment of products that have low or non-uniform water activity (aw) profiles.
Abstract: The benefits of high pressure processing (HPP) for microbial inactivation in food production include reduced thermal treatment and minimized effects on sensory and nutritional profiles. These benefits have resulted in increasing commercial production of high pressure pasteurized foods. In this review, the current state of the art in terms of vegetative cell and bacterial spore inactivation by HPP in complex food matrices is assessed with an emphasis on mechanisms of inactivation and treatment of products that have low or non-uniform water activity (aw) profiles. Low aw can be the result of a high concentration in solutes, the presence of oils/fats, or the physical removal of water through dehydration. Microbial inactivation in low aw environments remains a particular challenge for HPP and studies on microbial inactivation observed in the different types of low aw food matrices are reviewed in detail. Industrial relevance HPP-treated food products with low aw have been on the market since the nineties, but the mechanisms of microbial inactivation at low aw are still not well understood, which hinders the development of new applications in low or inhomogeneous aw food. This review summarizes the state of the art in terms of HPP microbial inactivation mechanisms in model systems and various low aw food environments. Thereby, it identifies existing and potential new applications as well as the current gaps and future research needs.
TL;DR: An extension of ICON is presented that enables it to perform as a large eddy simulation (LES) model, and the details of the implementation of the LES turbulence scheme in ICON are explained and test cases are performed to validate it against two standard LES models.
Abstract: ICON (ICOsahedral Nonhydrostatic) is a unified modeling system for global numerical weather prediction (NWP) and climate studies. Validation of its dynamical core against a test suite for numerical weather forecasting has been recently published by Zangl et al. (2014). In the present work, an extension of ICON is presented that enables it to perform as a large eddy simulation (LES) model. The details of the implementation of the LES turbulence scheme in ICON are explained and test cases are performed to validate it against two standard LES models. Despite the limitations that ICON inherits from being a unified modeling system, it performs well in capturing the mean flow characteristics and the turbulent statistics of two simulated flow configurations—one being a dry convective boundary layer and the other a cumulus-topped planetary boundary layer.
TL;DR: The method of composite pulses is demonstrated by creating a symmetric matter-wave interferometers which combines the advantages of conventional Bragg- and Raman-type concepts and leads to an interferometer with a high immunity to technical noise.
Abstract: By keeping its atomic components in the same state, a team was able to reduce one typical source of noise in a rotation-measuring device.