Academic literature on the topic 'Multidimensional spring system'

Schizophrenia is a serious mental disease whose pathogenesis has not been fully elucidated. Its clinical evaluation and diagnosis still highly depend on the clinical experience of doctors. It is of great scientific value and clinical significance to study the inducing factors and neuropathological mechanism of schizophrenia. Based on the four research problems of schizophrenia, this paper analyzes the data types that need to be stored in clinical trials and scientific research, including basic information, case report data, neuropsychological and cognitive function evaluation, magnetic resonance data, electroencephalogram (EEG) data, and intestinal flora data. Through the demand analysis of the system, including the data management part, data analysis part, the functional demand of the system management part, and the overall nonfunctional demand of the system, the overall architecture design, functional module division, and database table structure design of the system are completed. Adopting Browser/Server (B/S) architecture and front-end and back-end separation mode and applying Java and Python programming language, based on spring framework and database, a multidimensional information management system for schizophrenia is designed and implemented, which includes four modules: data analysis, data management, system management, and security control. In addition, each functional module of the system is designed and implemented in detail, and the software operation flow of each module is illustrated with the sequence diagram. Finally, the multidimensional data of schizophrenia collected in our laboratory were used for system test to verify whether the system can meet the needs of clinical big data management of schizophrenia and the multidimensional information management system of schizophrenia can meet the needs of clinical big data management. The information management system helps schizophrenic researchers to carry out data management and data analysis. It also has advantages that are easy to use, safe, and efficient and has strong scalability in data management, data analysis, and scalability. It reflects the innovation of the system and provides a good platform for the management, research, and analysis of clinical big data of schizophrenia.

The seismic response of a single-layer spherical lattice shell controlled by restorable sliding isolator is studied under different seismic excitations. The isolation system consists of flat steel-Teflon sliding isolators and superelastic SMA spring restrainers. The NiTi-SMA is used to fabricate helical spring for recentering control of the isolation system. In the first step of this investigation, the configuration scheme and functioning mechanism of a novel SMA spring restrainer are introduced briefly. Then, realistic mechanical behavior of large-scale superelastic NiTi helical spring is studied through a set of cyclic experimental tests. According to the obtained hysteresis loops, a mechanical model combining multilinear model and hysteresis model is developed to simulate the overall response of the SMA-based seismic restrainer. Besides, the sliding isolator is evaluated using a bilinear force-displacement hysteresis model. Finally, a 60 m span single-layer spherical lattice shell with substructure is modeled with finite element program. Nonlinear time history analyses of the controlled and uncontrolled lattice shell are performed considering multidimensional seismic inputs. The study shows that the seismic response of the controlled lattice shell can be effectively reduced by using isolation and control devices. Furthermore, the seismic response of the isolation system such as peak displacement and residual displacement can be effectively controlled by using the developed SMA spring restrainers.

For vehicle-bridge system, structural uncertainties, especially the interval variables with correlation, have a great influence on dynamic response. Therefore, this paper proposes an effective uncertainty analysis method for vehicle-bridge system based on multidimensional parallelepiped (MP) model, which can reasonably deal with the correlation of interval variables. First, the vehicle-bridge system is simplified as a four degrees-of-freedom mass-spring vehicle model running on a simply supported beam. MP model is adopted to describe the uncertainties of all the interval variables. Second, via affine coordinate system transform, the interval variables with correlation are transformed as the independent variables, which is very convenient for uncertainty analysis. Finally, the uncertain dynamic response is approximated through the first-order Taylor interval expansion, and the upper and lower bounds can be calculated using the dynamic response at midpoints and the partial difference multiplied by interval radius. Because the correlation is sufficiently considered, the uncertainty analysis results on vehicle–bridge interaction system will be much more accurate than the traditional interval analysis method (IAM). Numerical example demonstrates the correctness and effectiveness of the proposed method.

In this paper, through data analysis of multimodal knowledge graph optimized neural network and visual analysis of college students’ sports performance, we use huge graph, a graph database supporting distributed storage, to store domain knowledge in the form of the knowledge graph, use Spring Boot to build a server-side framework, use Vue framework combined with vis.js to visualize relational network graphs, and design and implement a knowledge-oriented. This paper proposes a visual analytics system based on the theory of visual analytics. Based on the idea of visual analytics, this paper presents a visual analytics framework combining predictive models. This framework combines the automated analysis capability of predictive models with interactive visualization as a new idea to explore the visual analysis of student behavior and performance changes. Using relevant predictive algorithms in machine learning, corresponding models are built to refine the importance of features for visual analysis and correlate behavioral data with achievement data. In this process, multiple prediction algorithms are used to build prediction models. The model effects are analyzed and compared to select the optimal model for use in the visual analytics framework. The graphical analytic view is integrated. EduRedar, an optical analytical system for sports data based on the performance prediction model, is designed and implemented to support multidimensional and multiangle data analysis and visualize the changes in college students’ sports and performance based on accurate campus exercise data.

Assessment of resource partitioning in pollinators at a particular place can be used to conserve plant communities by minimizing their inter-specific competition. Current study was conducted to investigate the occurrence of this phenomenon among plant communities under sub-tropical conditions for the first time in Pakistan. We considered the entire available flowering plant and floral visitor communities in the study area—Lal Suhanra forest of Bahawalpur, Pakistan- along with different variations among them based on morphology, color and symmetry (functional groups) i.e. four functional groups among insects and nine among plants. Weekly floral visitor censuses were conducted during spring season -from the first week of March to the fourth week of May 2018. Thirty individuals of each plant species -in bloom- were observed for floral visitors in each census. Plant species with different floral shapes, colors and symmetry did not show any significant resource partitioning. The Non-metric multidimensional scaling analysis followed by one-way ANOSIM test showed non- significant differences among all the pair of floral shapes, colors (except white and yellow) and symmetry (R-value < 0.168). However, SIMPER test suggested that flies were the most common group that contributed more towards within group similarities of different floral shapes (19 to 21% similarity), colors (16 to 30%) and symmetry (19%) followed by long-tongue bees i.e. 14 to 21%, 9 to 19% and 18%, respectively. Our results suggest that plant communities under sub-tropical conditions of Pakistan exhibit a generalist pollination system with no significant resource partitioning in pollinator species. Therefore, plant communities may have high competition for pollinator species which exhibits fewer implications of species loss on overall pollination process. Our study provides the basis for understanding the partitioning of pollinator guilds under sub-tropical conditions. Future studies should focus on functional traits in more detail at the community and the population scales for their possible impact on resource partitioning.

This study assessed differences in agility performance between athletes of team and individual sports by assessing change-of-direction speed (CODS) as pre-planned agility and reactive agility (RA) as non-planed in different spatial configurations. The study involved 36 individual (sprint, hurdles, jumping, tennis, and judo) and 34 team (soccer, basketball, and handball) athletes. CODS and RA were measured with a light-based reactive training system in a frontal (FR), universal (UN), semicircular (SC), and lateral (LA) design. Lower limb power and sprint performance were also measured in a 10 m single leg jump test and 15 m sprint. Individual athletes showed significantly better performance in three of the eight agility tests: LA-RA, UN-RA, and SC-CODS (p < 0.008, p < 0.036, and p < 0.027, respectively) and were found to present stronger correlations (p < 0.01) between jump test performance and the CODS condition. Team athletes showed stronger associations between sprint performance and the CODS condition. In the RA condition both jump and sprint performance showed stronger correlations in the group of individual athletes. Agility performance as measured by CODS and RA should improve with enhanced of motor proficiency. Finally, the tests applied in this experiment seem to be multidimensional, but require spatio-temporal adjustment for their implementation, so that they meet the requirements of the particular sport.

In recent decades, global and local vegetation phenology has undergone significant changes due to the combination of climate change and human activities. Current researches have revealed the temporal and spatial distribution of vegetation phenology in large scale by using remote sensing data. However, researches on spatiotemporal differentiation of remote sensing phenology and its changes are limited which involves high-dimensional data processing and analysing. A new data model based on data cube technologies was proposed in the paper to efficiently organize remote sensing phenology and related reanalysis data in different scales. The multidimensional aggregation functions in the data cube promote the rapid discovery of the spatiotemporal differentiation of phenology. The exploratory analysis methods were extended to the data cube to mine the change characteristics of the long-term phenology and its influencing factors. Based on this method, the case study explored that the spring phenology of Qinba Mountains has a strong dependence on the topography, and the temperature plays a leading role in the vegetation green-up date distribution of the high-altitude areas while human activities dominate the low-altitude areas. The response of green-up trend slope seems to be the most sensitive at an altitude of about 2000 meters. This research provided a new approach for analysing phenology phenomena and its changes in Qinba Mountains that had the same reference value for other regional phenology studies.

Intercropping plays an essential role in agricultural production, impacting the soil’s physical and chemical properties and microbial communities. However, the responses of ammonia-oxidizing microorganisms in the continuous-cropping soil to different intercropping systems in different growing seasons are still insufficiently studied. Here, we investigated the effects of seven intercropping systems (alfalfa (Medicago sativa L.)/cucumber, trifolium (Trifolium repens L.)/cucumber, wheat (Triticum aestivum L.)/cucumber, rye (Secale cereale L.)/cucumber, chrysanthemum (Chrysanthemum coronrium L.)/cucumber, rape (Brassica campestris L.)/cucumber, mustard (Brassica juncea L.)/cucumber) on soil physical and chemical properties, potential nitrification rate (PNR), soil ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) communities in the greenhouse in spring and autumn. The results showed that, compared with cucumber monoculture, intercropping increased the soil NH4+-N and NO3−-N. The chrysanthemum–cucumber, rape–cucumber, and mustard–cucumber treatments increased soil PNR. Intercropping increased the AOA and AOB abundances in two seasons, especially in rape–cucumber, wheat–cucumber, chrysanthemum–cucumber, and trifolium–cucumber treatments. The ratio of AOA and AOB decreased with seasonal variation. The wheat–cucumber and rape–cucumber treatments increased soil AOA community diversity. Seasonal variation had a significant effect on the relative abundance of the AOB community. Nonmetric multidimensional scaling analysis showed that the AOA and AOB community structures were obviously different from spring to autumn. Redundancy analysis showed that the AOA community was significantly regulated by moisture, NO3−–N, and available potassium (AK), while the AOB community was significantly regulated by moisture, available phosphorus (AP), AK, NO3−-N, and pH. Network analysis showed that the co-occurrence relationship and complexity of AOA and AOB communities were different in two growing seasons. The AOB community may play a critical role in ammonia oxidation in autumn. Taken together, intercropping improved soil physicochemical state, increased soil PNR and significantly altered soil AOA and AOB communities. Seasonal variation significantly altered the AOA and AOB communities’ structure and interaction between them. The effect of seasonal variation on AOA and AOB communities was greater than intercropping.

According to River Continuum Concept (RCC), channel morphology, including sediment loads and channel width, river habitat, flow regimes and water quality, differs from the tributary to the downstream river’s mainstem, allowing shifts in faunal composition from dominance of shredders to collectors downstream, respectively. Tributaries are responsible for contributing organic carbons, nutrients and water. However, such knowledge is still limited in the monsoon-dominated river systems of the Himalaya. The study was conducted in the river’s mainstem and tributaries of the Karnali River Basin, which are glacier and spring-fed river systems, respectively, in the western Himalaya, Nepal. A total of 38 river stretches in the river’s mainstem and tributaries were sampled during post-monsoon and pre-monsoon seasons in the years 2018 and 2019. Water quality parameters, such as pH, temperature, electrical conductivity, total dissolved solids, dissolved oxygen, alkalinity and hardness, and the benthic macroinvertebrates were studied. Ten subsamples of benthic macroinvertebrates were collected following the multi-habitat sampling approach at each site. High taxa richness was recorded in tributaries compared to the river’s mainstem while abundance was similar between river types. Non-metric multidimensional scaling (NMDS) formed two distinct groups, reflecting high similarities in benthic macroinvertebrate composition within the tributaries and river’s mainstem rather than between river types. Redundancy analysis (RDA) indicated water temperature and pH as major environmental predictors for benthic macroinvertebrate variability between river types. Therefore, river type-based conservation efforts that account for upstream–downstream linkages of aquatic biota and resources in freshwater ecosystems can ensure the ecological integrity of the whole river basin.

This updated issue of the professional publication Bulletin of the Slovenian Armed Forces is dedicated to the question of the Slovenian commitment to finding peaceful solutions to conflicts. As Commander­in­Chief of the Defence Forces of the Republic of Slovenia, I find this subject not only necessary but also entirely essential. There are many reasons for this. The historical experience of the Slovenian people has not always been pleasant regarding the preservation of national identity, manifested in the language as well as in the cultural and national tradition. Despite different repressive and denationalising measures taken by many foreign authorities, our ancestors managed to preserve the Slovenian nation through much wisdom, deep national awareness and political skill. The importance of consistent compliance with the provisions of international law in crisis situations, including wars, was seen in 1991. Slovenia won the war, not only in a military sense but also by complying with all legal norms, thus soon becoming recognised as a young European democratic country founded on high legal and moral principles. The lessons of war in 1991 increased the resolve of the Slovenian people for clear rejection of the use of force in finding solutions to any kind of conflict. For this reason, my pleasure at being invited to write about the topic of Slovenian people in the service of peace is that much greater, in part also due to the fact that I spent a large part of my professional life, from 1992 to 2005, working in the United Nations, first as the ambassador of the Republic of Slovenia, later as UN Assistant Secretary­General. In both functions I dealt with peacekeeping operations to a considerable extent. United Nations peacekeeping operations were in full swing at that time and underwent great development on the one hand, but also bitter disappointment and moments of deep doubt on the other. However, they continued to develop to the current extent. The topic of the Bulletin is presented in truly deep, scientific, theoretical and practical ways, from strategic and tactical levels, considering the evolutionary and transformational characteristics of peacekeeping operations, and deriving from historical experience. The most respected authors in the Slovenian professional field have thrown light upon important conceptual changes in the area of peacekeeping operations, which result from numerous factors, in particular from important geopolitical changes in the world. We must not disregard the increasing cooperation of regional organisations in the implementation of peacekeeping operations, which has indirectly brought about a different understanding of the term “peacekeeping operation” and opened technical discussions in the area of terminology as well as in the technical fulfilment of obligations, all the way to the question of the necessity of a preliminary UN mandate. These deficiencies can also be seen in Slovenia and point to the need for conducting a deep technical discussion as soon as possible and unifying the understanding of both the structure of the Slovenian Armed Forces and the broader defence and security system. The introductory and in particular the more theoretical parts of the Bulletin may be taken as important contributions in this regard. Some of the articles offer interesting historical insight into the cooperation of Slovenian men, and later women, in various endeavours for peace launched by individual great powers and international organisations. Although it is difficult to understand the military intervention of European forces on the island Crete in 1897 as a peacekeeping operation, the objective which is still in the forefront of contemporary efforts of the international community in this area was achieved for at least some time. This intervention ensured an armistice between the parties involved in the conflict and enabled a diplomatic solution on the island without unnecessary victims. The confidence that the highest political and military authorities in the Austro­Hungarian Empire had in the 2nd Battalion of the 87th Infantry Regiment from Celje was truly special. This was particularly the case because the military unit was mainly composed of Slovenes, and at the time of deployment in Crete its commander was a Slovene as well. However, we need to emphasise that such thinking is unconventional. By studying the literature on peacekeeping operations we see that such operations were first mentioned around 1919 in connection with peace conferences after the end of World War I and with managing various border issues in Europe, different plebiscites and other situations which, besides political and other diplomatic action, also required the protection of security and were followed by military operations intended for this particular purpose. History tells us much about peacekeeping operations intended to maintain truces. In these operations, coalition forces were deployed to an area in which a truce already existed and had to be maintained among well organised and disciplined armed forces. Today, the status of armed forces is quite different. We have to look at all of history and every aspect of international military engagement which is not armed combat by nature but a military presence with various aspects of employment of military force and the constant readiness and capability of peace forces to defend themselves effectively and be prepared to use weapons to fulfil their mandate. If today we see peacekeeping operations as valid in this respect, it is clear that we have to be familiar with history and evaluate what we can learn from past experience and how we are obliged to consider the present. Of course, we must consider the present. If we look at the status of peacekeeping operations today, we see how important this military activity is for the modern world. I will only dwell upon the United Nations, which from the standpoint of peacekeeping operations is the most important organisation operating today. Approximately 140,000 soldiers participate in peacekeeping operations under the auspices of the United Nations. No other military force has that number of uniformed personnel operating abroad. These people are assigned to eighteen currently active peacekeeping operations, each costing the organisation about seven billion dollars. This is the largest component of the budget of the United Nations. However, this expenditure is small in comparison to other kinds of military deployment outside the UN, to operations which are not peacekeeping operations by nature. Peacekeeping operations have become very multidimensional. The latest such operations, established in Africa (Darfur, Chad, Central African Republic), have been among the most demanding from the very beginning. We can thus conclude that peacekeeping operations are becoming increasingly more complex, which also results in a higher degree of risk. In 2007, 67 members of UN peacekeeping operations lost their lives. Looking at individual operations we see that six people died in Lebanon alone that year. Ever since peacekeeping operations have been in existence, Lebanon has been one of the most dangerous areas. Today, however, it is somewhat outside the sphere of interest. This may be due to the fact that there is a peacekeeping operation active in the area, on account of which a state of relative peace can be better maintained. Peacekeeping operations are both dangerous and multidimensional, multidimensional because they are no longer focused merely on keeping belligerent parties apart. Modern peacekeeping operations include both standard and supplemental functions. Providing a secure environment for political normalisation, humanitarian activity and development is a comprehensive task, requiring the engagement of peacekeeping forces in operations that are far from being common types of military deployment. This raises different questions about the training and competence of peacekeeping forces. We also have to ask ourselves how we can fully consider the lessons learned from previous peacekeeping operations and organise a system of command, particularly in organisations such as the United Nations, while at the same time making sure that national contingents do not lose their identity. There are thus two lines of communication, one through channels established by international organisations and the other through those established by national systems of armed forces. How to balance this and achieve efficient functioning? How to ensure the operation of different cultures, members and levels of competence in a way that facilitates the success of peacekeeping operations? These are always important questions to consider. In recent years the question of interest has pointed to the complexity of modern peacekeeping operations. Peacekeeping operations are frequently required to facilitate an environment in which elections can be conducted and assist in the establishment of a legal order and institutions to maintain that order. Both tasks are extremely demanding. The establishment of a safe environment for conducting elections in a country with poor communications, with no tradition of elections and with violence linked to every political event, is an extremely difficult task. The establishment of a legal order in areas with no such tradition or adequate infrastructure is even harder. There is often a need to include the civilian police, whose tasks in peacekeeping operations are very demanding. Civilian police have a number of other particularities besides problems connected to the aforementioned multidimensionality. It is necessary to adapt to the local environment in order to facilitate effective police performance. How to facilitate this in an environment such as Haiti, for example, with its difficult past? How to facilitate this in linguistically demanding environments such as East Timor until recently and in other difficult circumstances? These are all extremely demanding tasks. However, there is not much understanding with regard to all the details and problems arising from their implementation. The international political community is often satisfied merely by defining the mandate of a peacekeeping operation. For many people this signifies the solution to the problem, considering that the mandate is defined and that the deployment of forces will occur. However, this is where real problem solving only begins. Only then does it become obvious what little meaning general resolutions of the United Nations Security Council and other acts by which mandates are defined have in the context of actual situations. Therefore, I am of the opinion that we have to take a detailed look at experience from the distant past as well as the present. When speaking of the civilian police we also have to consider the fully human aspects that characterise every peacekeeping operation. Once I spoke to a very experienced leader of civilian police operations about the need to send additional police officers to the mission in Kosovo in the spring, when winter is over and people become more active, which also results in a higher crime rate. He explained that this is not only a problem in the area of this mission but elsewhere in Europe. In spring, the crime rate rises everywhere. Therefore it is difficult to find police officers during this time who are willing to leave their homeland, where they are most needed, and go to a mission area which is just then facing increased needs. I mention this to broaden understanding of the fact that the deployment of peacekeeping forces, both military and civilian police, is not only a matter of mandates and military organisation, but sometimes of the purely elementary questions that accompany social development. I have already mentioned that memory of the past is a very important component of considering present peacekeeping operations. I would like to conclude with another thought. I believe the manner of organising the knowledge of peacekeeping operations is of great importance to all countries, especially those that are new to cooperating in peacekeeping operations. This knowledge cannot be gained from books written at universities, but only from monitoring and carefully analysing the previous experiences of others. It is very important that this knowledge be carefully organised, that these experiences be carefully gathered and analysed, and that a doctrine be developed gradually. This doctrine is required for a country like Slovenia, which is new at conducting peacekeeping operations, to be able to manage well and define its role in international peacekeeping operations properly. To achieve this objective, a new country must cooperate with those countries which have been conducting peacekeeping operations for a long time and therefore have a richer experience. The neighbouring Austria is known to have one of the longest and most interesting systems of experience in peacekeeping operations within the United Nations. Ever since it joined the UN, Austria has been active in numerous activities linked to peacekeeping operations. Its soldiers and the civilian police have participated in a number of peacekeeping operations. Experience gained in this way is of great value, and using this experience is necessary for successful planning of and operating in future peacekeeping operations. The future will be complicated! At one time, when the members of peacekeeping operations numbered approximately 80,000, the United Nations thought that nothing more could be done, and a larger number of members was unthinkable. Today the number of members is significantly larger, development will most likely still continue and conditions will become even more demanding. I do not wish to forecast events which have not yet taken place. However, I would like to strongly emphasise that the history of peacekeeping operations is not over yet and that the future will be full of risks and challenges. I would also again like to stress the importance of this issue of the Bulletin of the Slovenian Armed Forces, which is entering a new decade, and express my pleasure at being able to note down a few thoughts. Let me particularly emphasise that as Commander­in­Chief of the Slovenian Defence Forces I will continue to devote special attention to achievements in the area of cooperation in peacekeeping operations in the future, having a special interest in these experiences. I thank the authors of the articles of this important issue of the Bulletin for their scientific and professional contributions – and I greatly respect those who have already done important work in the name of the Republic of Slovenia with the Slovenian flag on their shoulders, with the hope that they continue to fulfil their obligations in accordance with the rules.

As a consequence of the endless price growing of oil, and oil derivate fuels, automotive industry is experiencing a concerning decreasing in sales. Accordingly, in order to meet customer needs, there is every day a greater interest in solutions for increasing engine efficiency. On the other hand the growing attention to environmental problems leads to increasingly restrictive regulations, such as European EURO 4 and EURO 5. Direct injection of gaseous fuel has emerged to be a high potential strategy to tackle both environmental and fuel economy requirements. However since the electronic gaseous injection technology is rather new for automotive applications, limited experience exists on the optimum configuration of the injection system and the combustion chamber. To facilitate the development of these applications computer models are being developed to simulate gaseous injection, air entrainment and the ensuing combustion. This paper introduces a new method for modelling the injection process of gaseous fuels in multi-dimensional simulations. The proposed model allows holding down grid requirements, thus making it compatible with the three-dimensional simulation of an internal combustion engine. The model is validated and calibrated by comparing numerical results with available experimental data. To highlight the potential applications, some numerical results of the three-dimensional combustion process in a gas engine are presented.

Abstract The ability to deploy a planar surface to a desired convex profile can enhance foldable or morphing airfoils, deployable antennae and reflectors, and other applications where a specific profile geometry is desired from a planar sheet. A model using a system of rigid links joined by torsional springs of tailorable stiffness is employed to create an approximate curved surface when two opposing tip loads are applied. The physical implementation of the model uses compliant torsion bars as the torsion springs. A multidimensional optimization algorithm is presented to minimize the error from the rigid-link approximation and account for additional manufacturing and stress considerations in the torsion bars. A proof is presented to show that equal torsion spring spacing along the horizontal axis of deployed parabolic profiles will result in minimizing the area between the model’s rigid-link approximation and smooth curve. The model is demonstrated through the physical construction of a deployable airfoil surface and a metallic deployable parabolic reflector.

We consider topology optimization of lumped and continuous nonlinear metamaterial systems. Structures that consist of alternating layers of material with high impedance contrast are a simple example of a continuous phononic crystal that may exhibit nonlinearity. Analysis of this system, subject to prescribed constraints, shows that optimal design for a bilayered system consists of a thin nonlinear layer. Optimal, in this context, refers to a design which maximizes the frequency shift (and thus bandgap shift) at the edge of the first Brillouin Zone for the acoustic branch. Computer simulations of this system validate the predicted dispersion behavior. Optimization of two-dimensional arrays is presented using lumped-parameter models with nonlinear spring elements. Pattern-search algorithms identify topology (discrete mass distributions) that produce large increases in complete bandgap width. The analytical expression used in calculating nonlinear frequency shifts reveals that the largest contributions to the frequency shift are primarily produced from the resonant components of the system. Optimizing continuous multidimensional unit cells using a commercial finite-element code is briefly addressed.

The Discrete Channel Method (DCM) is presented as a new approach to model the transient multidimensional behavior of honeycomb-type catalytic converters. DCM combines a detailed modeling of effects taking place inside individual channels with the description of thermal effects occurring in the entire converter. The model is compared to experimental data measured under adiabatic conditions and to solutions generated by the finite difference method. DCM is applied to simulate the light-off behavior for different exhaust gas compositions under adiabatic and non-adiabatic conditions. The results show the influence of changing gas compositions and of radial heat losses on the performance of catalytic converters and aftertreatment systems. Hence, DCM is an effective and computationally fast method tailored for the integration in the engine analysis tool BOOST but also for stand-alone catalyst simulation.

Abstract To use the manifold possibilities that arc spraying offers to deposit wear resistance layers, the knowledge of the particle formation and their characteristics are necessary. The work is focused on studying the particle trajectories during arc spraying with cored wires. Different cored wires under various spraying parameters are investigated by means of a high speed camera. Particle properties in-flight, such as velocity and temperature are determined. Correlation between particle trajectories and particle characteristics at different spraying conditions are established. At the same time, the particle-laden gas flow is simulated numerically and the computed solutions are used to illustrate the utility of the proposed CFD model and compared with experimental results. The employed mathematical model represents a system of macroscopic conservation laws for the continuous gas phase and for the gas-solid mixture. This formulation makes it possible to circumvent the numerical difficulties associated with the implementation of a (potentially ill-posed) two-fluid model. The discretization in space is performed using a high-resolution finite element scheme based on algebraic flux correction in terms of local characteristic variables. The artificial diffusion operator is constructed on the discrete level and fitted to the local solution behavior using a multidimensional flux limiter of TVD type.