1,627 research outputs found
Nondestructive evaluation techniques for nickel-cadmium aerospace battery cells
The ac impedance characteristics of Ni-Cd cells as an in-situ, nondestructive means of determining cell lifetime, particularly with respect to the probability of premature failure were evaluated. Emphasis was on evaluating Ni-Cd cell impedance over a wide frequency range (10,000 to 0.0004 Hz) as the cells were subjected to charge/discharge cycle testing. The results indicate that cell degradation is reflected in the low frequency (Warburg) impedance characteristics associated with diffusion processes. The Warburg slope (W) was found to steadily increase as a function of cell aging for completely discharged cells. In addition, based on data for two cells, a high or rapidly increasing value for W signals imminent cell failure by one mechanism. Degradation by another mechanism is apparently reflected in a fall-off (roll-over) of W at lower frequencies. As a secondary result, the frequency dependence of the absolute cell impedance at low frequencies (5 - 500 mHz) was found to be a good indication of the cell state-of-charge
Wind tunnel calibration of the ''Arcasonde 1-A'' at simulated altitudes between 35 and 57 km
Subsonic wind tunnel calibration of Arcasonde 1-A atmospheric temperature sensing unit at simulated altitudes between 35 and 56 k
Deceleration of neutral molecules in macroscopic traveling traps
A new type of decelerator is presented where polar neutral molecules are
guided and decelerated using the principle of traveling electric potential
wells, such that molecules are confined in stable three-dimensional traps
throughout. This new decelerator is superior to the best currently operational
decelerator (Scharfenberg et al., Phys.Rev.A 79, 023410(2009)), providing a
substantially larger acceptance even at higher accelerations. The mode of
operation is described and experimentally demonstrated by guiding and
decelerating CO molecules.Comment: 10 pages, 3 figure
Operation of a Stark decelerator with optimum acceptance
With a Stark decelerator, beams of neutral polar molecules can be
accelerated, guided at a constant velocity, or decelerated. The effectiveness
of this process is determined by the 6D volume in phase space from which
molecules are accepted by the Stark decelerator. Couplings between the
longitudinal and transverse motion of the molecules in the decelerator can
reduce this acceptance. These couplings are nearly absent when the decelerator
operates such that only every third electric field stage is used for
deceleration, while extra transverse focusing is provided by the intermediate
stages. For many applications, the acceptance of a Stark decelerator in this
so-called mode significantly exceeds that of a decelerator in the
conventionally used () mode. This has been experimentally verified by
passing a beam of OH radicals through a 2.6 meter long Stark decelerator. The
experiments are in quantitative agreement with the results of trajectory
calculations, and can qualitatively be explained with a simple model for the 6D
acceptance. These results imply that the 6D acceptance of a Stark decelerator
in the mode of operation approaches the optimum value, i.e. the value
that is obtained when any couplings are neglected.Comment: 13 pages, 11 figure
Characteristics of a Family with the MEN-2A Syndrome
Results of screening and follow-up in a family with the MEN-2A syndrome are described. Fourteen (83%) subjects at risk were affected with medullary thyroid carcinoma (MTC). Asymptomatic pheochromocytoma and parathyroid hyperplasia were found in two instances each. Intrathyroidal MTC without metastases was found in the four youngest subjects and was associated with normal basal but abnormal pentagastrin-stimulated calcitonin (CT) levels. In the ten subjects with abnormal basal CT levels, metastatic spread to at least regional lymph nodes was found. In eight of these ten subjects, total thyroidectomy with excision of affected lymph nodes and additional radioiodine did not return CT levels to normal postoperatively. In the other two subjects, the CT levels returned to normal after thyroidectomy and an ablative dose of radioiodine, and remained normal during follow-up. This study confirms the view that family screening at a young age promotes the detection of MTC at a curable stage. Radioiodine as an adjunct to surgery may be of value in the prevention of tumor recurrence in patients with normal postoperative CT levels but residual thyroid tissue
A traveling wave decelerator for neutral polar molecules
Recently, a decelerator for neutral polar molecules has been presented that
operates on the basis of macroscopic, three-dimensional, traveling
electrostatic traps (Osterwalder et al., Phys. Rev. A 81, 051401 (2010)). In
the present paper, a complete description of this decelerator is given, with
emphasis on the electronics and the mechanical design. Experimental results
showing the transverse velocity distributions of guided molecules are shown and
compared to trajectory simulations. An assessment of non-adiabatic losses is
made by comparing the deceleration signals from 13-CO with those from 12-CO and
with simulated signals.Comment: 10 pages, 7 figure
Healthy ageing and home: The perspectives of very old people in five European countries
This paper reports on in-depth research, using a grounded theory approach, to examine the ways in which very old people perceive healthy ageing in the context of living alone at home within urban settings in five European countries. This qualitative study was part of a cross-national project entitled ENABLE-AGE which examined the relationship between home and healthy ageing. Interviews explored the notion of healthy ageing, the meaning and importance of home, conceptualisations of independence and autonomy and links between healthy ageing and home. Data analysis identified five ways in which older people constructed healthy ageing: home and keeping active; managing lifestyles, health and illness; balancing social life; and balancing material and financial circumstances. Older people reflected on their everyday lives at home in terms of being engaged in purposeful, meaningful action and evaluated healthy ageing in relation to the symbolic and practical affordances of the home, contextualised within constructions of their national context. The research suggests that older people perceive healthy ageing as an active achievement, created through individual, personal effort and supported through social ties despite the health, financial and social decline associated with growing older. The physicality and spatiality of home provided the context for establishing and evaluating the notion of healthy ageing, whilst the experienced relationship between home, life history and identity created a meaningful space within which healthy ageing was negotiated
Performance and variability of thirteen winter wheat composite cross populations (CCP) with differing cultivation histories.
Alternative breeding approaches in organic agriculture have started to address pressing issues such as the lack of appropriate plant varieties particularly suited to cope with higher biotic and abiotic stresses, generally found in low-input and organic production systems. This challenge, coupled with the additional pressure of loss of plant genetic diversity, has driven novel breeding approaches such as Composite Cross Populations (CCPs) and other genotype mixtures, thereby increasing both intra- and inter-varietal diversity. This High genetic Diversity (Hi-D) approach is relevant to organic agricultural systems for two reasons; firstly the availability of diverse germplasm improves chances of finding germplasm suited for low-input conditions as found in organic agriculture. Secondly, the comparatively large environmental variability in organic systems needs to be buffered with higher levels of in-field diversity. COBRA (Coordinating Organic plant BReeding Activities for Diversity) aims to support and develop plant breeding and seed production in Europe by increasing the use of plant material with High genetic Diversity (Hi-D) through coordinating, linking and expanding existing breeding and research in cereals (wheat and barley) and grain legumes (pea and faba bean)
Diabetes alone should not be a reason for withholding adjuvant chemotherapy for stage III colon cancer
Background: With increasing prevalence of diabetes mellitus and colon cancer, the number of patients suffering from both diseases is growing, and physicians are being faced with complicated treatment decisions. Objective: To investigate the association between diabetes and treatment/course of stage III colon cancer and the association between colon cancer and course of diabetes. Materials and Methods: Additional information was collected from the medical records of all patients with both stage III colon cancer and diabetes (n=201) and a random sample of stage III colon cancer patients without diabetes (n=206) in the area of the population-based Eindhoven Cancer Registry (1998–2007). Results: Colon cancer patients without diabetes were more likely to receive adjuvant chemotherapy compared with diabetic colon cancer patients (OR 1.8; 95% CI 1.2–2.7). After adjustment for age, this difference was borderline significant (OR 1.6; 95% CI 1.0–2.6). Diabetic patients did not have: significantly more side-effects from surgery or adjuvant chemotherapy; more recurrence from colon cancer; significantly shorter time interval until recurrence; or a poorer disease-free survival or overall survival. Age and withholding of adjuvant chemotherapy were most predictive of all-cause mortality. After colon cancer diagnosis, the dose of antiglycaemic medications was increased in 22% of diabetic patients, resulting in significantly lower glycaemic indexes than before colon cancer diagnosis. Conclusions: Since diabetic patients did not have more side-effects of adjuvant chemotherapy, and adjuvant chemotherapy had a positive effect on survival for both patients with and without diabetes, diabetes alone should not be a reason for withholding adjuvant chemotherapy.Journal of Comorbidity 2011;1(1):19–2
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