汽车应用中的磁阻传感器磁阻传感器系统的建模和仿真

磁阻效应支持汽车内的多种传感器应用。磁阻传感器主要用来测量机械系统的速度和角度。这样,磁阻传感器就成为电气元件、磁性元件和机械元件所组成的复杂系统的一部分。因为所有元件都会影响系统的反应,所以在规划系统及其操作时要非常重视对整个系统的仿真。下面重点讨论这种系统的建模和仿真。     

Zur Durchstanzbemessung von ausmittig beanspruchten Stützenknoten und Einzelfundamenten nach Eurocode 2

Punching Shear Capacity of Column‐Slab Connections with Moment Transfer and Footings According to Eurocode 2 The design provisions for punching of interior column‐slab connections without moment transfer are not sufficient for practical design issues. Very often, an additional moment transfer between slab and column has to be considered. While for interior columns moment transfer is caused by unequal spans or loadings, it is unavoidable for edge and corner columns. In addition, the determination of the punching shear capacity of footings is a very common problem. Compared to the German Building Code DIN 1045‐1, the Eurocode 2 provides different provisions to account for an interaction between moment and shear, and to determine the punching shear capacity of footings. In this paper, the Eurocode 2 provisions are critically reviewed and compared to the ultimate capacities of tests from literature.     

An Engineered Mannoside Presenting Platform: Escherichia coli Adhesion under Static and Dynamic Conditions

The study of the adhesion mechanisms of pathogens to host tissues has gained increased interest as bacterial adhesion is involved in the early stages of surface colonization and infection. Here we describe a platform to study the specific binding of the bacterium Escherichia coli (E. coli) K‐12 strain to molecularly well‐defined surfaces mimicking cellular interfaces. This approach uses a poly(ethylene glycol) brush interface, which displays synthetic determinants of the high mannose N‐linked glycans in a range of densities (3.8 × 10⁴–1.6 × 10⁵ mannosides µm^?2) for the investigation of multivalent interactions with bacteria. The bacterial attachment is mediated by specific interactions between the adhesive protein FimH located on the tip of the bacterial type 1 pili and the mannosylated surfaces. With synthetically engineered mannoses, it is found that the number of strongly adhering bacteria is co‐regulated by many structural physical parameters. Beyond the dependency on carbohydrate density, higher numbers of E. coli attach to the branched trimannose Man(α1–3)(Man(α1–6))Man compared to the monomannose, while larger oligomannoses exposing Man(α1–2) Man at their non reducing end show low binding capacity. The linker used between the mannose moiety and PEG is also affecting the binding efficacy of E. coli. The (hydrophobic) propyl linker results in higher bacteria numbers in comparison to the (hydrophilic) tri(EG), likely a consequence of additional stabilization of the binding complex by hydrophobic interactions. Furthermore, differences are observed in bacteria attachment between stagnant and flow conditions that depend on the type of mannose ligand. Finally, a photolithographic resist lift‐off combined with site‐selective assembly of the glycopolymers is used to produce micropatterns with bacteria colonies confined to defined areas and at controlled colony numbers.     

Bemessungsrelevante Kennwerte von Feinbeton für einaxiale Druckbeanspruchung

Design Parameters of Fine Grained Concrete for Uniaxial Compressive Loading Textile reinforced concrete (TRC) allows the design of thin‐structured concrete elements with a high load‐bearing capacity. The mechanical properties and stress‐strain relations under shortterm compressive loading of so called fine grained binder systems which are used as matrix are presented in this paper. The application of known mathematical formulations (e. g. simplified parabola‐rectangle stress‐strain curves for dimensioning purposes, prediction models for characteristic creep parameters) is investigated and design values of fine grained concrete are proposed.     

Diet Prevents Social Stress-Induced Maladaptive Neurobehavioural and Gut Microbiota Changes in a Histamine-Dependent Manner

Exposure to repeated social stress may cause maladaptive emotional reactions that can be reduced by healthy nutritional supplementation. Histaminergic neurotransmission has a central role in orchestrating specific behavioural responses depending on the homeostatic state of a subject, but it remains to be established if it participates in the protective effects against the insults of chronic stress afforded by a healthy diet. By using C57BL/6J male mice that do not synthesize histamine (Hdc^−/−) and their wild type (Hdc^+/+) congeners we evaluated if the histaminergic system participates in the protective action of a diet enriched with polyunsaturated fatty acids and vitamin A on the deleterious effect of chronic stress. Behavioural tests across domains relevant to cognition and anxiety were performed. Hippocampal synaptic plasticity, cytokine expression, hippocampal fatty acids, oxylipins and microbiota composition were also assessed. Chronic stress induced social avoidance, poor recognition memory, affected hippocampal long-term potentiation, changed the microbiota profile, brain cytokines, fatty acid and oxylipins composition of both Hdc^−/− and Hdc^+/+ mice. Dietary enrichment counteracted stress-induced deficits only in Hdc^+/+ mice as histamine deficiency prevented almost all the diet-related beneficial effects. Interpretation: Our results reveal a previously unexplored and novel role for brain histamine as a mediator of many favorable effects of the enriched diet. These data present long-reaching perspectives in the field of nutritional neuropsychopharmacology.     

Lactation response to short-term abomasal infusion of choline, inositol, and soy lecithin

Five lactating Holstein cows averaging 13 wk postpartum were used in a Latin square design to examine the effect of daily abomasal infusion of choline (22 g), myo-inositol (37 g), soy oil (325 ml), or crude soy lecithin (900 ml) on lactation performance. Dry matter intake was reduced by infusion of soy lecithin as compared with infusion of water (18.1 and 21.1 kg/d, respectively). Plasma beta-hydroxybutyrate concentration was increased when cows received the myo-inositol or soy lecithin infusion, and plasma glucose was lower when cows received the choline or soy lecithin treatment. Infusion of soy lecithin caused approximately a twofold increase in plasma triglyceride-rich lipoprotein concentration. Milk fat percentage and milk fat yield were greater during soy lecithin infusion (3.54%, 1.11 kg/d) than during water (3.09%, .98 kg/d) or soy oil (3.06%, .98 kg/d) infusion. This resulted in greater 3.5% FCM yield during soy lecithin infusion (31.6 kg/d) than during water (29.5 kg/d) or soy oil (29.6 kg/d) infusion. Infusion of phospholipid with triglyceride allowed more fatty acid to be infused without causing diarrhea. Infusion of triglyceride in the presence of phospholipid increased milk fat synthesis whereas infusion of triglyceride alone did not.     

The Americans with Disabilities Act: promise or problem?

Now that some states have restricted workers' compensation claims related to stress, the author predicts that the Americans with Disabilities Act, with its many ambiguous definitions, will become a favored target of litigation brought by employees seeking redress for work-related grievances. The ADA is reviewed in terms of the potential problems that employees increasingly are facing in regard to mental disabilities.     

Self-assembly of iron oxide-poly(ethylene glycol) core-shell nanoparticles at liquid-liquid interfaces

Nanoparticles (NPs) play an increasingly important role in the fabrication of functional advanced materials. Two major steps need to be carried out in order to achieve control of the material properties. First of all, the properties of the single NPs have to be under control, especially in relation to colloidal stability; aggregation and corrosion negate all the benefits associated to the nanoscopic dimensions. Secondly, the assembly process has to be controlled to achieve a material with the desired properties. We propose here to use stabilized ceramic NPs consisting of a magnetite core, coated by a poly(ethylene glycol) (PEG) shell and study their assembly at polar/ non-polar liquid interfaces, en route to fabricating functional NP membranes. These NPs show extraordinary stability in aqueous solutions achieved by anchoring linear PEG chains through an end-terminating nitroDOPA group to their surface. Furthermore, the core and shell sizes of these NPs can be independently varied with ease. We first describe the details of the NP synthesis and stabilization in bulk solutions, discussing the PEG molecular weight needed to achieve bulk stability. Subsequently, we demonstrate self-assembly of these particles at liquid-liquid interfaces (SALI) into monolayers of stable properties. SALI has been chosen as path for the assembly given its suitability for fabricating two-dimensional materials. We report here results from pendant drop tensiometry which illustrate the kinetics of NP adsorption at the liquid-liquid interface and highlight the role played by the molecular weight of the PEG shell in the interfacial assembly. In particular we show that the requisites to ensure particle stability at a liquid interface are more stringent compared to the bulk case.     

Integration of Low-Impact Development into the International Stormwater BMP Database

Low impact development (LID) strategies are being encouraged in many communities as an approach to reduce potential adverse impacts of development on receiving streams. Many questions exist regarding how well various LID strategies perform in different settings, just as similar questions have been raised regarding performance of traditional stormwater best management practices (BMPs). Whereas historical focus on BMP performance has been water quality concentrations or loads, characterization of volume reduction benefits for both conventional and LID practices is increasingly an objective of researchers and stormwater managers. More than a decade ago, Urban Water Resources Research Council (UWRRC) members worked to develop a set of standardized monitoring and reporting protocols for traditional BMPs and to establish a master database for the purpose of evaluating BMP performance and the factors affecting performance. This effort culminated in the International Stormwater BMP Database (www.bmpdatabase.org), which contains data for more than 360 BMPs and continues to operate as a clearinghouse for stormwater BMP data and performance analyses. During 2008–2009, the International Stormwater BMP Database project expanded to better integrate LID into the database and develop a set of metrics that can be used to characterize BMP performance with regard to surface runoff volume reduction. This paper provides a condensed overview and progress report on the LID-focused effort, including the following topics: (1)?monitoring guidance for LID at the overall site development level, (2)?an overview of recent changes to the International Stormwater BMP Database to better accommodate LID studies, (3)?a summary of LID studies currently included in the database, and (4)?a proposed approach for evaluating performance of LID studies with regard to reducing surface runoff volumes.     

Calibrating whole building energy models: An evidence-based methodology

This paper reviews existing case studies and methods for calibrating whole building energy models to measured data. This research describes a systematic, evidence-based methodology for the calibration of these models. Under this methodology, parameter values in the final calibrated model reference the source of information used to make changes to the initial model. Thus, the final model is based solely on evidence. Version control software stores a complete record of the calibration process, and the evidence on which the final model is based. Future users can review the changes made throughout the calibration process along with the supporting evidence. In addition to the evidence-based methodology, this paper also describes a new zoning process that represents the real building more closely than the typical core and four perimeter zone approach. Though the methodology is intended to apply to detailed calibration studies with high resolution measured data, the primary aspects of the methodology (evidence-based approach, version control, and zone-typing) are independent of the available measured data.