Combined micro-cogeneration and electric vehicle system for household application: An energy and economic analysis in a Northern European climate

In recent years, Denmark boosted investments in renewable energy and electrification of transportation. The Danish Agenda proposed that all primary energy consumption will be covered by renewable sources such as wind, biomass and solar by 2050. These changes require significant investment and re-thinking of entire energy infrastructures and types of consumption. The Agenda also suggested, among other things, improving the efficiency of energy systems.In this paper, the interactions between charging an electric car and an innovative cogeneration system for household application (micro-solid oxide fuel cell with an integrated heating system) are investigated. The charge of the electric car by the cogenerator produces waste heat that can be used to partially cover the heat demand of the house. In this way it may be possible to increase overall efficiency and decrease total energy costs. Different innovative strategies are proposed and analyzed to manage charging an electric car and efficiently using the waste heat available. The aims of this study are to make the system grid-independent, to decrease the thermal stress of SOFCs and to determine the nominal power of an integrated heating system. The results show energy efficiency and economic profitability of the system, even if subsidies are not included.     

Phase study on solid fission products,Ba, Sr and Zr in oxide fuel

Behavior of pseudo-fission products (Ba, Sr, and Zr) as oxides in UO₂ has been investigated by means of high-temperature X-ray diffraction and microprobe analysis. Two identifiable compounds were formed as reaction products in the mixed oxides which initially consisted of UO₂, BaO, SrO, and ZrO₂ powder. These compounds were present and were identified crystallographically as (Ba, Sr) ZrO₃ and (Ba, Sr)UO₃ after heat treatment of the powders at 1500°C for 30 min. Both compounds are isostructural with perovskite, CaTiO₃, and the lattice parameters of both (Ba, Sr)ZrO₃ and (Ba, Sr)UO₃ decrease with increasing content of Sr. (Ba, Sr)UO₃ is decomposed almost completely at 1800°C while (Ba, Sr) ZrO₃ is stable up to 2000°C. The behavior of Ba, Sr, and Zr in fuel under irradiation is discussed.     

The effects of VDT work on the regulation of hemodynamics compared with aging

Urinary excretions of aldosterone, blood pressure, and heart rate were examined for three age groups of volunteers searching for target words on VDT for two hours. Aldosterone excretion did not change in the young and middle-aged groups, but increased in the elderly group. Blood pressure decreased midway through the work in the young group, and increased during the work in the middle-aged and elderly groups. Aldosterone excretion did not increase during hard-copy work or during VDT work with large letters, but increased during VDT work with small letters. During VDT work with both large and small letters, blood pressure increased. During hard-copy work, neither blood pressure nor heart rate changed, although blood pressure increased after the work. These data suggest that the sympathetic nervous activation represented by the increases in aldosterone excretion and blood pressure occurred definitively during VDT work with small letters under the conditions of this study. It is also suggested that this effect is enhanced by aging.     

Microsatellite instability and frameshift mutations in the Bax gene in hereditary nonpolyposis colorectal carcinoma

Patients with ulcerative colitis (UC) are at higher risk for cancer. Risk factors are duration of disease, extent of colitis, associated primary sclerosing cholangitis and possibly early onset of UC in childhood. Epithelial dysplasias are considered as precursors of colorectal cancer within the concept of an inflammation-dysplasia-carcinoma sequence. Dysplasia originates multifocally and is difficult to identify by colonoscopy. Histomorphological diagnosis can also be problematical. Surveillance programs utilize colonoscopy with random biopsies to diagnose dysplasia in patients with risk factors. The efficiency of these programs can be markedly increased when certain rules are applied. The ultimate aim must be to perform a proctocolectomy in patients at higher risk before invasive cancer develops. With only a few exceptions, colorectal cancer in UC can be treated by restorative proctocolectomy. Partial resection of the colon should be avoided because of the high frequency of occult carcinomas and multifocal carcinogenesis. There are first results that indicate a higher risk for malignant deterioration in the terminal ileum. After an ileoanal pouch procedure patients with chronic pouchitis seem to have a higher risk for dysplasia. At the moment the risk for malignancy cannot be calculated because of the relatively short follow-up time after ileoanal pouch procedures. However, it is recommended that after restorative proctocolectomy patients be followed by endoscopy and random biopsies for the rest of their lives.     

Emulsion polymerisation of vinyl acetate in relation to the chemical structure of polyvinyl alcohol

The effects of content and sequence distribution of residual acetyl groups in the polymer chain, and carbonyl content of polyvinyl alcohol, on the emulsion polymerisation of vinyl acetate in the presence of polyvinyl alcohol were investigated. Properties of modified polyvinyl alcohol grades as a protective colloid were also studied. Results show that the viscosity, particle size, stability and the freeze-thaw stability of the emulsion are determined largely by the fine chemical structure of the polyvinyl alcohol used in the polymerisation.     

Pd–Pt bimetallic catalyst supported on SAPO‐5 for catalytic combustion of diluted methane in the presence of water vapor

The examination of the combustion of a trace amount of methane over Pd‐ion‐exchanged silicoaluminophosphate‐5 (Pd‐SAPO‐5) at low temperature in the presence of water vapor reveals that water vapor strongly depresses methane combustion and causes a significant decrease in catalytic activity with time. The newly prepared bimetallic catalyst Pd–Pt‐SAPO‐5, on the other hand, shows higher performance for methane combustion under similar conditions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Clock synchronization of MPEG-2 services over packet networks

We address the problem of time-base synchronization for MPEG services in the presence of network jitter. The conventional methods to obtain a stable clock indication are based on Phase Locked Loops (PLLs). They have the disadvantage of a long startup phase and thus are unsuitable for services that require simultaneous accuracy and rapidity. We develop a new time-base synchronization technique based on a Least-square Linear Regression algorithm (LLR). We show that LLR is able to perform time-base synchronization with the same accuracy as of a PLL and with a substantial gain of rapidity. Finally, we discuss the implementation of the LLR technique as an intermediate time-base synchronization level between the network and a generic multimedia application.     

Combustion of a trace amount of CH4 in the presence of water vapor over ZrO2-supported Pd catalysts

Combustion of a trace amount of CH₄ over Pd catalysts supported on calcined ZrO₂ was examined under nearly exhaust gas conditions where the temperature is not so high and water vapor coexists. High catalytic activity was obtained with ZrO₂ support calcined at 1073 and 1273 K. The durability test at 673 K for 100 h revealed that the activity of these catalysts hardly decreased, while that of the Pd catalysts supported on calcined Al₂O₃ were much decreased in the course of time. These results demonstrated the advantages of ZrO₂ as a support for Pd catalysts in the present reaction. This revised version was published online in November 2006 with corrections to the Cover Date.     

The change in colour critical flicker fusion (CFF) values and accommodation times during experimental repetitive tasks with CRT display screens

Two groups of normal subjects were loaded an experimental visual task, or a calculating and discriminating task, on a CRT display screen under different work speeds and amounts. The colour (red, green and yellow) CFF values of the subjects were measured every 15 min during the task and their accommodative function, represented by the accommodation time, was measured before and after the task. The two groups of subjects showed no significant differences in the pattern of change in the colour CFF values. The green and yellow CFF deteriorated significantly at 30 min after the start of the task. The red CFF values decreased significantly at 15 min after the start of the task and this conditions continued to the end of the task. Both groups showed a lengthening accommodation relaxation time but no change in the accommodation relaxation time after the task. This increase in the relaxation time was larger in the group of subjects who were loaded a larger amount of work at a higher speed. The results suggest that the decrease in the CFF value of the subject, particularly when the subject sees light directly using a CRT display screen, does not signify the decline in the activity or consciousness level of the brain centre alone.