Polarisation-diversity receiver for coherent FSK communications

A polarisation-insensitive optical heterodyne receiver, in which two signals with orthogonal polarisations are independently detected and demodulated, and subsequently combined, has been demonstrated for FSK-modulated signals at 50 Mbit/s with a sensitivity of ?55.5 dBm (Pe=10?9). The receiver uses the entire received signal and local oscillator signal with only one photodiode in each branch. Differences between the two PINFET detectors result in a ±ldBm sensitivity variation for all polarisation states of the received signal.     

Evaluation of the radiation pattern of a split aperture linear phased array for high frequency imaging

Developing transducer arrays for high frequency medical imaging is complicated because of the extremely small size and spacing of the array elements. For example, a 50 MHz linear phased array requires a center-to-center spacing of only 15 mum (one-half wavelength in water) to avoid the formation of grating lobes in the radiation pattern of the array. Fabricating an array with these dimensions is difficult using conventional technology. A split aperture design that permits much larger element spacing (3 to 4 times) while avoiding the formation of grating lobes is described. The 3-D radiation pattern of a 1.9x1.4 mm, 50-MHz split aperture linear phased array with 33 transmit elements and 33 receive elements has been evaluated theoretically. The azimuthal beam width is 90 mum at a distance of 4.0 mm. Grating lobes are suppressed by at least 60 dB at distances >4.0 mm (~f/2). The elevation beam width is 220 mum at 4.0 mm, and a useful depth of field over the axial range from 4 to 10 mm is obtained.     

European Consumers' Perceptions of Time–Temperature Indicators in Food Packaging

Food quality is an essential aspect of the food industry. Time–temperature indicator (TTI) technology has the capability to provide information on temperature fluctuations that temperature‐sensitive food products have undergone. However, the adoption of the TTI technology in the consumer market has yet to materialize despite the many benefits that TTIs bring to food manufacturers, retailers and consumers. One of the reasons for this could be the general lack of knowledge regarding consumers' perceptions of TTIs. The aim of this study is to understand the consumers' knowledge, interest and perceptions of TTIs. To reach this aim, 16 focus group discussions and a quantitative survey were conducted in four European countries (Finland, Greece, France and Germany) during May–October 2012. Consumers' views on both the TTI technology concept and two commercially available TTI applications were studied. The results of the study show that consumers in all countries appreciate and understand TTI technology and associate differing benefits with it, especially so in warmer countries. On the other hand, the studied applications did not meet all consumers' expectations implying the need for further work to enable TTIs to gain a wider acceptance. Copyright © 2014 John Wiley & Sons, Ltd.     

Capturing the User Mindset – Using the Online Research Community Method in Packaging Research

The rapid development of Web 2.0 technology has enabled new types of online research methods. The collective intelligence of online communities or ‘crowds’ can be harnessed to contribute actively to bodies of knowledge, work or value by means of crowdsourcing. This paper presents a case study of using a crowd‐based research method, more specifically, an online research community (ORC) for collecting information, user experiences and ideas from a community of packaging users. We will discuss the benefits, challenges and opportunities that the method offers to packaging research. A total of 137 participants were recruited to a closed online platform, with 86 of them as active participants. The discussion topics and tasks were pre‐determined by the researchers, and new topics were introduced daily over a period of 13 days. The discussions were moderated in order to keep them on topic and to propose additional questions when required. The platform suited well for gathering user information, feedback and insights on various packaging designs and development topics. The case study also demonstrated that the ORC method can provide valuable insights on usability, packaging communication, consumer behaviour and user experiences. The research yielded rich data, even on such a complex issue as the relation of packaging to food loss prevention. The method can be employed to collect both quantitative and qualitative data from a crowd. However, answers provided by individual participants may remain less grounded and less rich in detail than those elicited with other qualitative methods, such as interviews or focus groups. Copyright © 2014 John Wiley & Sons, Ltd.     

Ultrasound evaluation of mechanical injury of bovine knee articular cartilage under arthroscopic control

A local cartilage injury can trigger development of posttraumatic osteoarthritis (OA). Surgical methods have been developed for repairing cartilage injuries. Objective and sensitive methods are needed for planning an optimal surgery as well as for monitoring the surgical outcome. In this laboratory study, the feasibility of an arthroscopic ultrasound technique for diagnosing cartilage injuries was investigated. In bovine knees (n = 7) articular cartilage in the central patella and femoral sulcus was mechanically degraded with a steel brush modified for use under arthroscopic control. Subsequently, mechanically degraded and intact adjacent tissue was imaged with a high frequency (40 MHz) intravascular ultrasound device operated under arthroscopic guidance. After opening the knee joint, mechanical indentation measurements were also conducted with an arthroscopic device at each predefined anatomical site. Finally, cylindrical osteochondral samples were extracted from the measurement sites and prepared for histological analysis. Quantitative parameters, i.e., reflection coefficient (R), integrated reflection coefficient (IRC), apparent integrated backscattering (AIB), and ultrasound roughness index (URI) were calculated from the ultrasound signals. The reproducibilities (sCV %) of the measurements of ultrasound parameters were variable (3.7% to 26.1%). Reflection and roughness parameters were significantly different between mechanically degraded and adjacent intact tissue (p < 0.05). Surface fibrillation of mechanically degraded tissue could be visualized in ultrasound images. Furthermore, R and IRC correlated significantly with the indentation stiffness. The present results are encouraging; however, further technical development of the arthroscopic ultrasound technique is needed for evaluation of the integrity of human articular cartilage in vivo.     

Differences in Vole Preference, Secondary Chemistry and Nutrient Levels Between Naturally Regenerated and Planted Norway Spruce Seedlings

Field voles (Microtus agrestis) cause severe damage to young Norway spruce (Picea abies) plantations during wintertime in Fennoscandia. We experimentally investigated vole preference for winter-dormant, naturally regenerated seedlings; spring-planted seedlings; or autumn-planted seedlings; and how preference corresponds with seedling chemistry. Voles showed the highest preference for autumn-planted seedlings and the second highest for spring-planted seedlings, while naturally regenerated seedlings were avoided. The stems of the autumn-planted seedlings contained higher concentrations of nitrogen and piperidine alkaloids and lower concentrations of stilbenes than did the other groups. In addition to differences between naturally regenerated and planted seedlings, we investigated seasonal differences in naturally regenerated P. abies needle and bark secondary chemistry. While piperidine alkaloid concentrations did not vary with season, the soluble non-tannin phenolics of needles and the condensed tannins of bark were lower in May than in November or January. At the time of planting, the concentration of bark piperidine alkaloids was higher in autumn-planted than in spring-planted seedlings. We detected two alkaloids not previously found in P. abies, 2-methyl-6-propyl-1,6-piperideine and a tentatively identified pinidine-isomer. Our results demonstrate that vole choice of spruce seedlings is promoted by high nitrogen and low stilbene content, both associated with seedlings planted late in the season. As vole damage is linked to seedling chemistry, damage potentially could be mitigated by advancing planting or by manipulating plant chemistry in nurseries.     

Factors influencing the choice of solution-specific business models

Services are receiving an increasing amount of attention in project-based firms. This has led project suppliers to employ new business models; the project supplier can offer services as an additional component of the project or take full responsibility for the operation and maintenance of the facility throughout its life-cycle. In this paper, we build on the idea that within the context of project-based firms, assessing business models requires a solution level of analysis which implies services as integral parts of project offering. We analyze business models in five solutions that were delivered by a power plant supplier firm. The evidence clearly demonstrates that there are variations in business models at the solution level. The paper further contributes to existing research by empirically identifying factors that influence the choice of business model for a particular solution. Finally, we formulate propositions on how these identified factors influence the choice of a business model for an individual solution.     

优化磁性粒子为基础的系统的DNA纯化方案的重要性

从复杂生物基质中快速、高效地分离核酸是在获取各种实验的最佳起始原料的重要一步。磁性粒子为基础的操作流程提供了一个快速简单的解决方案,它特别适合用于自动化,在获得纯净和完整的DNA或RNA时以最少的动手时间获得良好的重现性结果。因此,必须优化基于磁珠的纯化流程来达到最高质量与数量的核酸提取。本文介绍了一个自动化、高速、以磁性粒子为基础的纯化系统来实现理想的DNA纯化方案,并考察了不同搅拌速度组合,以及在洗脱步骤的加热效应对DNA纯化数量和质量的影响。     

Separating Biogenic and Adsorbed Pools of Silicon in Sediments Using Bayesian Inference

There are several potentially mobile pools of silicon in sediment, e.g. biogenic Si (BSi), dissolved Si and adsorbed Si (AdSi) which makes the studying of a single pool very difficult because of the interference caused by other Si pools. In order to evaluate the impact that different Si pools have on the Si cycle of water ecosystems, it is important to have reliable estimates of the pool sizes. The objective of this study was to estimate the joint concentration distributions of two pools, AdSi and BSi, in, of a small catchment area in southern Finland. The potential correlation between BSi and AdSi was studied to find out if the AdSi pool can be inferred from the total pool (BSi + AdSi). The potential error caused by simultaneous extraction of AdSi in BSi determinations was also investigated. Because all extraction methods include variability due to measurement imprecision and inter-sample variation, the different sources of variation were explicitly separated to be able to infer the underlying true variation of AdSi and BSi within the study area. We have utilized Bayesian inference for this task.