Experimental Study of an Adding Interferometer at Millimeter Waves

In order to study an original detection architecture for future cosmology experiments based on wide band adding interferometry, we have tested a single baseline bench instrument based on commercial components. The instrument has been characterized in the laboratory with a wide band power detection setup. A method which allows us to reconstruct the complete transfer function of the interferometer has been developed and validated with measurements. This scheme is useful to propagate the spurious effects of each component till the output of the detector.     

Determination of pistachio drying behaviour and conditions in a solar drying system

The main object of this study is to determine the drying behaviour and conditions of shelled and unshelled pistachio samples using both solar assisted and open sun drying. For each drying experiment, 100 g each of unshelled and shelled pistachio were used. The least‐squares method was applied to find the drying curve equation of pistachio. During the experiments, shelf temperatures, weight loss of pistachio, moisture content of air, and distribution of solar radiation were measured; and presented depending on the drying time. Also, the mass shrinkage ratios of shelled and unshelled pistachio samples were determined, and the experimental uncertainty ratio was calculated as 15–16.5 per cent based on the experimental results. It was deduced that the shelled and unshelled pistachio samples in the solar assisted forced convection dryer were perfectly dried at temperatures of 50±10°C in the time period of 6 h. Whereas, the samples in the open sun drying were not sufficiently dried at temperatures of 28±4°C in the same time period. Hence, it is suggested that the pistachio samples with approximately 29.0 per cent of moisture are dried in the solar assisted convection dryer at 50±10°C of temperature in the time period of approximately 6 h in order to protect from the negative climatic and environmental effects. However, it is not desirable to dry the pistachio samples in the open sun because of greater drying time, dirt, dust and harmful insects. Copyright © 2001 John Wiley & Sons, Ltd.     

Introducing two landscape components from Turkey: Irim and Kesik

A very particular set of landscape components, namely the irim and the kesik, found in the peri-urban rural area called Karabaglar, are considered. This area is in the contiguous land of the city of Mugla, in southwestern Turkey, and is administered by its municipality. It has a rural character, yet also includes summerhouses for the inhabitants of the city. Physical resemblance of the irim and the kesik to the hedgerow suggests similar functions, but a closer look reveals that they have a wider range of features and aspects. Functioning not only as a marker of agricultural land sub-divisions, they also play an important role in the hydrology of the area. While their specific traditional features can be used in designed landscapes, the intention here is, first, to introduce the irim, the kesik and the very special setting offered by Karabaglar, which are now under the pressure of urban encroachment. A comparison with the hedgerow is nevertheless useful in order to better understand related aspects and features.     

Comparison of the sensory profiles of regular and reduced-fat commercial processed cheese spreads

The sensory character of 16 samples of commercial, processed cheese spread has been characterized. Samples were selected to provide information on variations both between brands and, for products differing in fat content, within brands. Products were rated for eight flavour attributes and six textural attributes by a panel of 13 professional assessors. Significant differences in both the flavour and the texture of the spreads were associated with brand. No systematic differences were found between the flavour attributes and the fat content of the spread. However, differences were revealed between spreads – classified on the basis of fat content as regular, light and ultra light – in the sensory dimensions associated with texture and mouth feel. Nevertheless, within some brands the effect of reducing fat content was minimal. This result was probably achieved by other changes in product formulation.     

Construction projects and the environment in Palestine

Continuing the series of papers on construction in Palestine, one of the most densely populated areas in the world, the author concentrates on the need for harmonized development to sustain the environment. An analysis of the Gaza seaport project demonstrates the need to educate professionals working within the construction industry on environmental issues, in particular the steps needed in carrying out the environmental impact assessment of any construction project. The author believes that further studies to increase knowledge are needed. Poursuivant sa serie d'articles sur les activites du batiment en Palestine, l'une des regions les plus peuplees au monde, l'auteur se penche ici sur la necessite d'un amenagement harmonise soucieux de l'environnement et s'inscrivant dans la duree. Suite a une analyse du projet de port: maritime a Gaza, il apparait clairement que les professionnels du secteur de la construction ont besoin d'une formation dans le domaine de la protection de l'environnement, en particulier pour la realisation d'etudes d'impact sur l'environnement de projets de construction. L'auteur estime que des etudes complementaires sont necessaires pour approfondir les connaissances en la matiere.     

On a consistent field transfer in non linear inelastic analysis and ultimate load computation

In this work we propose a field transfer operator for remeshing carried out in the course of incremental analysis of a non linear inelastic behavior. The proposed procedure is geared towards the ultimate load computation of a complex structure, where we choose the appropriate mesh grading for each different phase of computations, starting with a coarse mesh for the initial linear response and going towards a more refined mesh for highly nonlinear inelastic response. The proposed projection operator is developed on the basis of diffuse approximation method. The key feature of such an operator is to guarantee the conservation of relevant mechanics quantities which ensures a superior performance of the proposed field transfer with respect to the standard remeshing procedure. We present the illustrative results both for an isotropic damage model and standard plasticity model, indicating very satisfying performance.     

Measurements and statistical model calculations of activation cross-sections for 26Mg(n,α)23Ne reaction between 13.6 and 14.9 MeV neutron energies

Activation cross-sections were measured at neutron energies from 13.6 to 14.9 MeV for the reaction ²⁶Mg(n,α)²³Ne. The production of relatively short-lived activity and the spectra accumulation have been carried out by the cyclic activation method. Corrections were made for the effects of gamma-ray attenuation, random coincidence summing (pulse pile-up), dead time, and scattered low energy neutron contribution. Statistical model calculations for which the pre-equilibrium emission effects are taken into consideration were also performed. Results were compared with the previous investigations.     

Prestressed polymeric matrix composites: Longevity aspects

Elastically prestressed polymeric matrix composites (EPPMCs) are produced by stretching fibers (e.g., glass) within the composite during matrix curing. The resulting prestress can enhance mechanical performance, without increasing section dimensions or weight. Viscoelastically prestressed polymeric matrix composites (VPPMCs) can provide similar benefits, these being produced by subjecting polymeric fibers (e.g., nylon 6,6) to a creep load, which is released prior to molding. Although VPPMCs offer simplified processing and flexibility in product geometry, long‐term viscoelastic activity within the prestressing fibers is sensitive to time‐temperature limitations. In this study, nylon 6,6 fiber‐polyester resin samples were subjected to accelerated ageing. Using time‐temperature superposition, the samples were maintained at 70°C for 2,298 h, representing a 20‐fold ageing increase over previous work. Subsequent Charpy impact testing (at 20°C) demonstrated that the VPPMC samples absorbed ∼40% more energy than corresponding control (unstressed) counterparts; i.e., no deterioration in impact performance was observed, over a duration equivalent to ∼25 years at 50°C. In contrast, the longevity of EPPMCs remains unknown, but it is suggested that progressive localized matrix creep at the fiber‐matrix interface regions may cause a deterioration in elastically generated prestress with time and/or elevated ambient temperatures. POLYM. COMPOS., 37:2092–2097, 2016. © 2015 Society of Plastics Engineers     

An application of univariate marginal distribution algorithm in MIMO communication systems

The paper discusses a sequence detector based on univariate marginal distribution algorithm (UMDA) that jointly estimates the symbols transmitted in a multiple input multiple output (MIMO) communication system. While an optimal maximum likelihood detection using an exhaustive search method is prohibitively complex, it has been shown that sphere decoder (SD) achieves the optimal bit error rate (BER) performance with polynomial time complexity for smaller array sizes. However, the worst‐case complexity of SD is exponential in the problem dimensions, this brings in question its practical implementation for larger number of spatial layers and for higher‐order signal constellation. The proposed detector shows promising results for this overly difficult and complicated operating environment, confirmed through simulation results. A performance comparison of the UMDA detector with SD is presented for higher‐order complex MIMO architectures with limited average transmit power. The proposed detector achieves substantial performance gain for higher‐order systems attaining a near optimal BER performance with reduced computational complexity as compared with SD. Copyright © 2009 John Wiley & Sons, Ltd.     

Heat emission from thermal skirting boards

The performance of three hydronic skirting heating systems was investigated. The main focus of the study was to ascertain whether thermal skirting boards served by low-temperature supply flow were able to suppress strong downdraught. The evaluation was made for a two-person office room with mechanical ventilation. Computational Fluid Dynamics (CFD) simulations and three different draught rating models were employed to predict the level of thermal discomfort inside the room. CFD results were validated against several analytical calculations and four sets of experimental data presented in previous studies. Numerical simulations showed that all three skirting heating arrangements were able to cover transmission and ventilation thermal losses of the office room. Horizontal and vertical heat distribution inside the room was uniform for all heating systems. CFD simulations also showed that thermal skirting boards served by 40 and 45 °C supply flow had difficulty in reducing the velocity of the downdraught at ankle level. Consequently the draught rating in this region was around or slightly above 15% for these cases. In contrast, heat-emitting skirting boards supplied by 55 °C hot water showed a better ability to suppress downdraught, and the proportion of people sensing draught at 0.1 m above the floor was low. The conclusion of this study was that thermal performance of hydronic skirting heaters with low-temperature water supply must be improved in order to counter strong downdraughts, in particular where such systems may be combined with heat pumps of other low-valued sustainable energy sources.