Catalysis with homogeneous membranes loaded with nanoscale metallic clusters and their preparation

Catalytically powerful, non-porous membranes were manufactured from two highly gas permeable poly(amide imides) consisting of structures with moieties of 3,3'-dimethylnaphthidine and hexafluoroisopropylidene (6F) or hexafluoroisopropylidene 2,2-bis(phthalic acid anhydride) (6FDA) and 6F. The catalysts are pure precious metals or precious metal alloys dispersed on a nanoscale uniformly throughout the membrane. The membranes are characterized by electron microscopy, gas permeability, hydrogen uptake and, as a model reaction, the decomposition of nitrous oxide by hydrogen to nitrogen and water catalyzed by Pd/Ag. The permeance to hydrogen and nitrous oxide is round 2–10^-6 cm³ (STP) /cm²·s·cmHg for membranes of 40–50μm in thickness.     

Variance analysis of identified linear MISO models having spatially correlated inputs,with application to parallel Hammerstein models

This contribution concerns variance analysis of linear multi-input single-output models when the inputs are temporally white but where different inputs may be correlated. An expression is provided for the variance of a linearly parametrized estimate of the frequency response function from one block, i.e. from one input to the output. In particular, this expression reveals that the variance increases in one block when the number of estimated parameters in another block is increased, but levels off when the number of parameters in the other block reaches the number of parameters in the block in question. It also quantifies exactly how correlation between inputs affects the resulting accuracy and a graphical representation is provided for this purpose. The results are applicable to parallel MISO Hammerstein models when the nonlinearities are known and generalize an existing variance expression for this type of model.     

冠带层新平台技术

子午线轮胎出现不久，就采用钢丝带束层代替了纤维带束层，这对于实现子午线轮胎提高使用寿命和改善操纵性能的潜能是必要的。     

A case study of factor influencing role improvisation in crisis response teams

Common characteristics of crisis situations are ambiguous and unplanned for events. The need for improvised roles can therefore be an imperative factor for the success of an operation. The aim of this study is to deepen the understanding of the processes taking place during improvised work “as it happens”. A case study of a crisis management team at work is presented and provides an in-depth analysis of the information and communication flow of persons acting in improvised roles, including contextual factors influencing the task at hand. The analysis suggests that three main factors lay behind decreased performance by the team when some of its members were forced to take on roles for which they lacked professional training; lack of language skills, lack of domain knowledge and insufficient organizational structure of the tasks. Based on the observations from this case study, we suggest three ways of improving a team’s performance and hence resilience when forced to improvise due to lack of personnel in one or more required competence areas. These are training to take on the responsibility for tasks or roles outside ones professional area of specialization, developing formal routines for changes in roles and tasks and developing and using tools and routines for information sharing.     

A selective conductive polymer-based sensor for volatile halogenated organic compounds (VHOC)

A novel poly(p-xylylene), PPX, derivative bearing alkoxyphenyl side groups was electrochemically synthesized in 87% yield. The polymer, poly(4′-hexyloxy-2,5-biphenyleneethylene) (PHBPE), presented a fraction (92%) soluble in common organic solvents. It showed to be thermally resistant up to 185 °C. UV–vis analysis revealed an E_gap of 3.5 eV. Gas sensors made from thin films of 10-camphorsulfonic acid-doped PHBPE deposited on interdigitated electrodes exhibited significant changes in electrical conductance upon exposure to five VHOCs: 1,2-dichloroethane, bromochloromethane, trichloromethane, dichloromethane and tetrachloromethane. The conductance decreased after exposure to tetrachloromethane and increased after exposure to all the other VHOCs. Three-dimensional plots of relative response versus time of half response versus time of half recovery showed good discrimination between the five VHOCs tested.     

Connecting the Empire: New Research Perspectives on Infrastructures and the Environment in the (Post)Colonial World

In the academic debate on infrastructures in the Global South, there is a broad consensus that (post)colonial legacies present a major challenge for a transition towards more inclusive, sustainable and adapted modes of providing services. Yet, relatively little is known about the emergence and evolution of infrastructures in former colonies. Until a decade ago, most historical studies followed Daniel Headrick’s (1981) “tools of empire” thesis, painting—with broad brush strokes—a picture of infrastructures as instruments for advancing the colonial project of exploitation and subordination of non-European peoples and environments. This paper explores new research perspectives beyond this straightforward, ‘diffusionist’ perspective on technology transfer. In order to do so, it presents and discusses more recent studies which focus on interactive transfer processes as well as mechanisms of appropriation, and which increasingly combine approaches from imperial history, environmental history, and history of technology.There is much to gain from unpacking the changing motives and ideologies behind technology transfer; tracing the often contested and negotiated flows of ideas, technologies and knowledge within multilayered global networks; investigating the manifold ways in which infrastructures reflected and (re)produced colonial spaces and identities; critically reflecting on the utility of large (socio)technical systems (LTS) for the Global South; and approaching infrastructures in the (post)colonial world through entangled histories of technology and the environment. Following David Arnold’s (2005) plea for a “more interactive, culturally-nuanced, multi-sited debate” on technology in the non-Western world, the paper offers fresh insights for a broader debate about how infrastructures work within specific parameters of time, place and culture.     

Valorisation of mango seed via extraction of starch: preliminary techno-economic analysis

Reducing environmental impacts and obtaining economic benefits based on utilisation of waste materials are drivers for the implementation of cleaner production policies and technologies in food processing industries. Starch is a very versatile material with a wide range of applications in the food, pharmaceutical, textile, paper, cosmetic and construction industries. In Ethiopia, starch is widely used in the textile industry. To meet the starch demand, the country imports approximately 45% of the starch used in the country. Consequently, it is imperative to find additional sources of starch that could substitute for the amount of starch that is currently being imported. Mango seeds, a waste material that is disposed of after consumption of mangos, were studied for potential use as an alternative resource for starch production. The results showed that starch extraction from mango seeds was facile and a good quality product was obtained. The present study is concerned with a techno-economic analysis for industrial production of starch from mango seeds. The study shows that extraction of starch from waste mango seeds is feasible: the project is financially viable with an accounting rate of return of 83% and a break-even analysis of 78% with a payback period of 2 years.     

Frequency-domain identification of continuous-time ARMA models from sampled data

The subject of this paper is the direct identification of continuous-time autoregressive moving average (CARMA) models. The topic is viewed from the frequency domain perspective which then turns the reconstruction of the continuous-time power spectral density (CT-PSD) into a key issue. The first part of the paper therefore concerns the approximate estimation of the CT-PSD from uniformly sampled data under the assumption that the model has a certain relative degree. The approach has its point of origin in the frequency domain Whittle likelihood estimator. The discrete- or continuous-time spectral densities are estimated from equidistant samples of the output. For low sampling rates the discrete-time spectral density is modeled directly by its continuous-time spectral density using the Poisson summation formula. In the case of rapid sampling the continuous-time spectral density is estimated directly by modifying its discrete-time counterpart.