Structural-thermal FE simulation of vibration and heat generation of cracked steel plates due to ultrasound excitation used for vibrothermography

A major drawback of ultrasound excited thermography applied to metal components manifests in the pronounced frequency dependence of crack detectability. In order to investigate the crack face interaction by which it is constituted whether a certain crack can be detected or not structural-thermal Finite Element simulations of a massive steel plate are conducted using ANSYS/LS-DYNA considering the physical roughness of the crack faces. The achieved numerical results are in a good agreement with experimental data of a performed ultrasonic sweep thermography (UST)

Chiral metamaterials: retrieval of the effective parameters with and without substrate

After the prediction that strong enough optical activity may result in negative refraction and negative reflection, more and more artificial chiral metamaterials were designed and fabricated at difference frequency ranges from microwaves to optical waves. Therefore, a simple and robust method to retrieve the effective constitutive parameters for chiral metamaterials is urgently needed. Here, we analyze the wave propagation in chiral metamaterials and follow the regular retrieval procedure for ordinary metamaterials and apply it in chiral metamaterial slabs. Then based on the transfer matrix technique, the parameter retrieval is extended to treat samples with not only the substrate but also the top layers. After the parameter retrieval procedure, we take two examples to check our method and study how the substrate influences on the thin chiral metamaterials slabs. We find that the substrate may cause the homogeneous slab to be inhomogeneous, i.e. the reflections in forward and backward directions are different. However, the chiral metamaterial where the resonance element is embedded far away from the substrate is insensitive to the substrate.Comment: 15 pages, 6 figure

Патриарх горного образования Сибири

Описан жизненный путь горного инженера Д. А. Стрельникова, профессора Томского политехнического института

Identification of lineage-specific marker for therapeutic targeting of mast cells

The number of people in the modern world being affected by allergic diseases and asthma has reached epidemic proportions. With over 1 out of three people requiring some sort of treatment for allergic disease, the burden placed onto industrialized nations healthcare systems is increasing. Mild forms of allergic diseases, such as allergic rhinitis, can be treated with anti-histamines or immunological desensitization. However, more severe forms of disease, such as asthma and atopic dermatitis, require a reduction of systemic inflammation by administration of broad acting systemic immunosuppressants, to effectively alleviate symptoms. However, systemic immunosuppression often results in susceptibility to infection. Mast cells, which are evidently involved in numerous allergic pathologies, have not been adequately targeted by conventional therapeutics. Specific removal of mast cells, by means of antibody-dependent depletion, would interrupt the allergic cascade and might yield significant benefit for patients. In order to develop such a mAb- mediated mast cell ablation approach we sought to established proof of principle in a well-controlled system with our newly developed transgenic mouse model. The Cpa3hCD4 mouse model expresses a truncated human CD4 receptor from a knockin into the mast cell specific Cpa3 locus. With this model system, employing an artificial mast cell marker cell surface protein, we could show that several tissue-resident mast cell compartments can be safely and efficiently depleted after intravenous α- hCD4 administration. To identify a physiologically relevant target on the surface of mast cells, we underwent extensive mass spectrometry-assisted proteomic profiling of primary mouse and human mast cells. Analysis of the data revealed a cross- species conserved mast cell protein signature, among which we found several drugable receptors. Quantitative analysis, paired with flow cytometry-based verification of the cell surface expressed mast cell proteins allowed us to identify several highly expressed mast cell specific cell surface markers. Targeting of one of these receptors with an α-CD63-Immunotoxin resulted in the efficient depletion of mast cells in vitro. In vivo however, efficacy of mast cell depletion was limited by excessive on-target toxicities. Along these lines, we are currently evaluating the herein identified physiological mast cell targets for cellular depletion by different antibody-mediated mechanisms

Heterogeneity in criminal behavior after child birth: the role of ethnicity

This paper documents behavioral differences in parental criminality between majority and minority ethnic groups after child birth. The particular effect we exploit is that of the gender of the first-born child on fathers’ convictions rates. Based on detailed judicial and demographic data from New Zealand, we first show that the previously documented inverse relationship between having a son and father’s criminal behaviour holds across the average of the population. However, when splitting the fathers’ sample by ethnicity, the effect appears to be entirely driven by the white part of the population and that there is no effect on the native Māori. The strong ethnic divide is observed along many dimensions and challenges the implicitly made assumption in the economics of crime literature that findings are universally applicable across cultures and race

Ortsaufgelöste Erkennung von Ermüdungsschäden an Schweißnähten mit Hilfe aktiver Infrarot-Thermografie

The paper presents two thermographical approaches for the detection of fatigue damages in welded joints of mild carbon steel S355. First, a recently developed extension of the thermoelastic stress analysis is utilised for early crack detection on butt welds. At low frequency fatigue loading the method separates the linear and nonlinear temperature response related to the harmonic loading. Significant changes during the test reveal the progressive fatigue damage evolution. On the tested components localised damage processes could be observed as early as 10 to 30 % of the total fatigue lifetime. The method is especially suited for laboratory testing since a defined and damage relevant loading is necessary. As a second approach the ultrasound excited thermography is applied using a high intensity ultrasonic transducer working at 20 kHz. Induced elastic waves lead to oscillations of the tested component. Dry friction at the crack faces provides a localised heat generation which allows for crack detection. It was found that the crack can be detected after 35 % of the fatigue lifetime. Although the crack detection on metal components is strongly dependent on the ultrasonic frequency a high potential for a future mobile application can be awarded to this method

Extended thermoelastic stress analysis applied to carbon steel and CFRP

Thermoelastic Stress Analysis (TSA) by means of radiometric full field measurements has been primarily developed over 20 years ago. Although the underlying physics concerning the linear thermal response with respect to the loading as well as dissipative and nonlinear effects have been extensively studied in the past the potential of applications in the field of non destructive testing does not seem to be exhausted, yet. As an extension of the classic thermoelastic analysis the use of second harmonic temperature amplitudes for spatially resolved damage detection due to cyclic plasticity in ferritic low-alloy carbon steel is demonstrated. Temperature variations of several mK are found to be useful as a fatigue damage indicator. Furthermore the application to partially delaminated CFRP coupons under cyclic peeling load reveals that the classic thermoelastic measurement is able to visualise the locally stressed woven fibre ply. In contrast, the evaluation of the spatial temperature response at the double loading frequency clearly allows to detect the delamination front of homogeneous coupons whereas the dominating bending stress distribution is efficiently suppressed

Harbinger II: Deployment and Evolution of Assertive Community Treatment in Michigan

Assertive Community Treatment (ACT) is now recognized as the model proven to be most successful in working with clients with long-term, severe mental illness. The first documented research replication study of ACT was Harbinger of Grand Rapids, in Kent County, Michigan. The Harbinger program influenced significant programmatic changes throughout the public mental health system in Michigan. This paper describes this evolution in community mental health locally and why these changes came about. The state-level strategy to implement replications of Harbinger is described, as well as funding and monitoring mechanisms that have now resulted in over 100 successful ACT programs in Michigan. For mental health administrators, the implications discussed include the future of ACT promotion and implementation, within the reality of a managed care framework.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44094/1/10488_2004_Article_414562.pd

Optical chirality without optical activity: How surface plasmons give a twist to light

Light interacts differently with left and right handed three dimensional chiral objects, like helices, and this leads to the phenomenon known as optical activity. Here, by applying a polarization tomography, we show experimentally, for the first time in the visible domain, that chirality has a different optical manifestation for twisted planar nanostructured metallic objects acting as isolated chiral metaobjects. Our analysis demonstrate how surface plasmons, which are lossy bidimensional electromagnetic waves propagating on top of the structure, can delocalize light information in the just precise way for giving rise to this subtle effect.Comment: Opt. Express 16, 12559 (2008

Myeloid Cell-Restricted Insulin Receptor Deficiency Protects Against Obesity-Induced Inflammation and Systemic Insulin Resistance

A major component of obesity-related insulin resistance is the establishment of a chronic inflammatory state with invasion of white adipose tissue by mononuclear cells. This results in the release of pro-inflammatory cytokines, which in turn leads to insulin resistance in target tissues such as skeletal muscle and liver. To determine the role of insulin action in macrophages and monocytes in obesity-associated insulin resistance, we conditionally inactivated the insulin receptor (IR) gene in myeloid lineage cells in mice (IRΔmyel-mice). While these animals exhibit unaltered glucose metabolism on a normal diet, they are protected from the development of obesity-associated insulin resistance upon high fat feeding. Euglycemic, hyperinsulinemic clamp studies demonstrate that this results from decreased basal hepatic glucose production and from increased insulin-stimulated glucose disposal in skeletal muscle. Furthermore, IRΔmyel-mice exhibit decreased concentrations of circulating tumor necrosis factor (TNF) α and thus reduced c-Jun N-terminal kinase (JNK) activity in skeletal muscle upon high fat feeding, reflecting a dramatic reduction of the chronic and systemic low-grade inflammatory state associated with obesity. This is paralleled by a reduced accumulation of macrophages in white adipose tissue due to a pronounced impairment of matrix metalloproteinase (MMP) 9 expression and activity in these cells. These data indicate that insulin action in myeloid cells plays an unexpected, critical role in the regulation of macrophage invasion into white adipose tissue and in the development of obesity-associated insulin resistance