Deformation of AR glass roving embedded in the warp knitted structure

In this paper, the influence of a high‐performance (HP) roving deformation on the composite textile performance and the ultimate composite textile properties is discussed. Also, the deformation of an HP roving during the tightening of a knit stitch is addressed in this paper. The impact of different orientations of the stitch and tensions on the deformation of the roving is analytically investigated. For this purpose, an equation has been derived using the stitch length, the knot tightening tension and the packing density of the HP roving by means of data of the roving deformation in a right‐angle stitch and by a number of assumptions. Furthermore, an empirical method to measure the deformation of an alkali‐resistant (AR) glass roving in a right‐angle stitch is utilized in this study. It was found that the required tension to obtain maximum deformation of an AR glass roving when used in the weft direction is significantly low in comparison with other orientations of the roving. For instance, a 0.41 N tension is sufficient to obtain maximum deformation of an AR glass roving in the weft direction; however, it is estimated that a 3.40 N tension is required to deform the same warp roving embedded in a stitch for a 10‐mm length stitch.     

Geometrical and mechanical properties of a non-crimp fabric applicable for textile reinforced concrete

Nowadays, non-crimp fabrics (NCFs) are extensively employed in many applications like textile reinforced concrete (TRC). Warp-knitting is a well-known system to incorporate high-performance rovings straightly as a grid fabric with specified mesh size. In these kinds of fabrics, geometry of the rovings and configuration of fabric play a vital role in TRC performance and eventually properties of TRC. The influence of knitting process parameters like knitting tension and stitch length on roving geometry and fabric configuration is systematically addressed in this study. To monitor and control knitting tension, a set of tension-meters is installed and calibrated on different positions on knitting yarns. Accordingly, three levels of tension with three different stitch lengths, namely 2.1, 4.2, and 6.3?mm (nine categories) are produced to investigate the influence of knitting parameters on roving geometry and NCFs properties. It is demonstrated that the stitch length is more effective than knitting tension to control both roving geometry and NCFs properties. Indeed, the packing density of fibers and profile shape of warp and rovings can be controlled via appropriate stitch length. Moreover, to fabricate a stiff NCF, the small stitch length with a high level of knitting tension must be applied simultaneously.     

The cytotoxicity of fatty acid/α‐lactalbumin complexes depends on the amount and type of fatty acid

Complexes of the milk protein, α‐lactalbumin, and the fatty acid, oleic acid, have previously been shown to be cytotoxic. Complexes of α‐lactalbumin and five different fatty acids (vaccenic, linoleic, palmitoleic, stearic, and elaidic acid) were prepared and compared to those formed with oleic acid. All complexes were cytotoxic to human promyelocytic leukemia‐derived (HL‐60) cells but to different degrees depending on the fatty acid. The amount of fatty acid per α‐lactalbumin molecule was found to correlate with the cytotoxicity; the higher the number of fatty acids per protein, the more cytotoxic the complex. Importantly, all the tested fatty acids were also found to be cytotoxic on their own in a concentration dependent manner. The cytotoxic effect of complexes between α‐lactalbumin and linoleic acid, vaccenic acid, or oleic acid was further investigated using flow cytometry and found to induce cell death resembling apoptosis on Jurkat cells. Practical applications: Cytotoxic complexes of α‐lactalbumin and several different fatty acids could be produced. The cytotoxicity of all the variants is similar to that previously determined for α‐lactalbumin/oleic acid complexes.     

A W-Band MMIC Radar System for Remote Detection of Vital Signs

In medical and personal health systems for vital sign monitoring, contact-free remote detection is favourable compared to wired solutions. For example, they help to avoid severe pain, which is involved when a patient with burned skin has to be examined. Continuous wave (CW) radar systems have proven to be good candidates for this purpose. In this paper a monolithic millimetre-wave integrated circuit (MMIC) based CW radar system operating in the W-band (75–110?GHz) at 96?GHz is presented. The MMIC components are custom-built and make use of 100?nm metamorphic high electron mobility transistors (mHEMTs). The radar system is employing a frequency multiplier-by-twelve MMIC and a receiver MMIC both packaged in split-block modules. They allow for the determination of respiration and heartbeat frequency of a human target sitting in 1?m distance. The analysis of the measured data is carried out in time and frequency domain and each approach is shown to have its advantages and drawbacks.     

Effect of gas composition and gas utilisation on the dynamic response of a proton exchange membrane fuel cell

The transient response of a proton exchange membrane fuel cell (PEMFC) was measured for various cathode gas compositions and gas utilisations (fraction of supplied reactant gas which is consumed in the fuel cell reaction). For a PEMFC operated on pure hydrogen and oxygen, the cell voltage response to current steps was fast, with response times in the range 0.01–1 s, depending on the applied current. For a PEMFC supplied with air as cathode gas, an additional relaxation process related to oxygen transport caused a slower response (approximately 0.1–2 s depending on the applied current). Response curves up to approximately 0.01 s were apparently unaffected by gas composition and utilisation and were most likely dominated by capacitive discharge of the double layer and reaction with surplus oxygen residing in the cathode. The utilisation of hydrogen had only a minor effect on the response curves, while the utilisation of air severely influenced the PEMFC dynamics. Results suggested that air flow rates should be high to obtain rapid PEMFC response.     

Methods derived from nonlinear dynamics for analysing heart rate variability

Methods from nonlinear dynamics (NLD) have shown new insights into heart rate (HR) variability changes under various physiological and pathological conditions, providing additional prognostic information and complementing traditional time- and frequency-domain analyses. In this review, some of the most prominent indices of nonlinear and fractal dynamics are summarized and their algorithmic implementations and applications in clinical trials are discussed. Several of those indices have been proven to be of diagnostic relevance or have contributed to risk stratification. In particular, techniques based on mono- and multifractal analyses and symbolic dynamics have been successfully applied to clinical studies. Further advances in HR variability analysis are expected through multidimensional and multivariate assessments. Today, the question is no longer about whether or not methods from NLD should be applied; however, it is relevant to ask which of the methods should be selected and under which basic and standardized conditions should they be applied.     

Brain evoked potentials reflect how emotional faces influence our decision making.

Emotion is usually not discussed as a relevant variable in rational models of decision making—but may be one. The present electroencephalographic study demonstrates the influence of emotional primes (angry, happy faces) on purchase decisions. In a within-subject design, pictures of an apartment were shown to participants who then had to make Go/NoGo decisions on whether to rent it. Their decision should be based either on its price or on its brightness. In two thirds of the trials, emotional prime pictures of happy versus unhappy faces preceded the purchase target (apartment); in one third of the trials no prime was given. Response certainty was evaluated by means of reaction times (RT) and peak amplitude of the event-related potential N200. Facial primes accelerated decisions (RT) irrespective of affective expression. Positive face primes elicited larger N200 amplitudes during purchase decision compared to negative ones. Price-based decisions were made faster and elicited larger N200 than brightness-based decisions. These results support the cognitive-tuning model of decision making and validate the N200 as sensitive measure for the interplay of cognitive and affective aspects in decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Survey of air pollution in Cotonou, Benin--air monitoring and biomarkers

Exposure to genotoxic compounds present in ambient air has been studied in Cotonou, Benin, a city where two-stroke motorbikes are the major form of transportation and gasoline quality is poor. Personal monitoring and biomarkers were used to assess the exposure. Non-smoking taxi-moto drivers (city) and village residents were the study subjects. Benzene exposure was significantly higher in the city, as compared to the village (76.0+/-26.8 microg/m(3) versus 3.4+/-3.0, p=0.0004). Urinary excretion of benzene and S-phenylmercapturic acid (S-PMA) were also highest in subjects living in the city, whereas 1-hydroxypyrene was not different. The level of total polycyclic aromatic hydrocarbons (PAHs), associated with particles, ranged from 76.21 to 103.23 in Cotonou versus 1.55 ng/m(3) for the village. Determination of DNA damage in lymphocytes showed that subjects from the city had elevated number of lesions compared to subjects in the village in terms of bulky DNA adducts, 8-hydroxy-2'-deoxyguanosine and 5-methylcytosine, whereas DNA fragmentations analysed by alkaline gel electrophoresis was not different between the subjects. In conclusion, this study shows that air pollution is pronounced in Cotonou, Bénin and is associated with elevated levels of DNA damage in residents of the city compared to people living in a non-polluted rural village.     

Hygrothermisches Verhalten eingebetteter Holzbalkenköpfe im innnengedämmten Außenmauerwerk: Heizungstechnisch gestützte Innendämmung bei Holzbalkendecken

The hygrothermic performance of wooden beam ends embedded in an inside insulated outside wall considering a heating system. Heating pipe aided inside thermal insulation in case of a timber joist floor. An improvement of the hygrothermal performance of worth preserving facades by means of an inside insulation is proved correct for crucial projects also, using capillary activ thermal insulation materials or a vapor retarder dependent on the relative humididy. On the other hand in case of embedded wooden beam ends there are controversial discussions The experts suggest proposals from an airthight construction and the using of fungicides and the sorptive binding of moisture up to a beam end completely open for air flow rate. This paper is focused to the hygric problems of the wooden beam ends. A lot of measurements are carried out in situ under condition of use in testhouses and by means of a teststand in the Building Physics testing floor of the FHL. In each cases the experiments are supported by a numerical simulation of the coupled heat and mass transfer. Apart from the seasonal process of the wooden moisture content and the hygrothermal state of the air gaps of the beam heads area the results quantify also the effect of local heat transfer by means of heating channels near the floor board area and through so‐called passive and active heat bars within the wooden beam ends.     

Beanspruchungsanalyse von Holzbauteilen durch 2D‐Photogrammetrie

Strain analysis of solid wood and glued laminated timber members by close range photogrammetry. The assumption of critical fracture mechanics parameters for the evaluation of the load‐bearing safety of structural units of full and board laminated timber in loaded areas and disturbance ranges the use of fracture mechanics is required. Realistic parameters can be gained only from experimental investigations that are transferred to the determination of the crack opening and the crack length with subsequent FE‐simulation. Due to the insufficient appropriation of measured data gained by tactile position encoders in conventional measuring procedures it is advisable to investigate crack growth with the help of the photogrammetry. Using the developed measuring system it is now possible to measure the crack geometry exactly for the determination of fracture mechanics parameters. Additionally a complete picture of the local deformations and the validity of a test can be improved considerably by the possibility of the varying number of discrete measuring points.