Voltage-temperature charge verification testing of 34 ampere-hour nickel-cadmium cells

This testing was designed to evaluate various voltage-temperature (V-T) charge curves for use in low-Earth-orbit (LEO) applications of nickel-cadmium battery cells. The trends established relating V-T level to utilizable capacity were unexpected. The trends toward lower capacity at higher V-T levels was predominant in this testing. This effect was a function of the V-T level, the temperature, and the cell history. This effect was attributed to changes occurring in the positive plate. The results imply that for some applications, the use of even lower V-T levels may be warranted. The need to limit overcharge, especially in the early phases of missions, is underlined by this test program

The fixed-cycle traffic-light queue with multiple lanes and temporary blockages

Traffic-light modelling is a complex task, because many factors have to be taken into account. In particular, capturing all traffic flows in one model can significantly complicate the model. Therefore, several realistic features are typically omitted from most models. We introduce a mechanism to include pedestrians and focus on situations where they may block vehicles that get a green light simultaneously. More specifically, we consider a generalisation of the Fixed-Cycle Traffic-Light (FCTL) queue. Our framework allows us to model situations where (part of the) vehicles are blocked, e.g. by pedestrians that block turning traffic and where several vehicles might depart simultaneously, e.g. in case of multiple lanes receiving a green light simultaneously. We rely on probability generating function and complex analysis techniques which are also used to study the regular FCTL queue. We study the effect of several parameters on performance measures such as the mean delay and queue-length distribution.</p

The Fixed-Cycle Traffic-Light queue with multiple lanes and temporary blockages

Traffic-light modelling is a complex task, because many factors have to be taken into account. In particular, capturing all traffic flows in one model can significantly complicate the model. Therefore, several realistic features are typically omitted from most models. We introduce a mechanism to include pedestrians and focus on situations where they may block vehicles that get a green light simultaneously. More specifically, we consider a generalization of the Fixed-Cycle Traffic-Light (FCTL) queue. Our framework allows us to model situations where (part of the) vehicles are blocked, e.g. by pedestrians that block turning traffic and where several vehicles might depart simultaneously, e.g. in case of multiple lanes receiving a green light simultaneously. We rely on probability generating function and complex analysis techniques which are also used to study the regular FCTL queue. We study the effect of several parameters on performance measures such as the mean delay and queue-length distribution

Practical guidance for applying the ADNEX model from the IOTA group to discriminate between different subtypes of adnexal tumors.

All gynecologists are faced with ovarian tumors on a regular basis, and the accurate preoperative diagnosis of these masses is important because appropriate management depends on the type of tumor. Recently, the International Ovarian Tumor Analysis (IOTA) consortium published the Assessment of Different NEoplasias in the adneXa (ADNEX) model, the first risk model that differentiates between benign and four types of malignant ovarian tumors: borderline, stage I cancer, stage II-IV cancer, and secondary metastatic cancer. This approach is novel compared to existing tools that only differentiate between benign and malignant tumors, and therefore questions may arise on how ADNEX can be used in clinical practice. In the present paper, we first provide an in-depth discussion about the predictors used in ADNEX and the ability for risk prediction with different tumor histologies. Furthermore, we formulate suggestions about the selection and interpretation of risk cut-offs for patient stratification and choice of appropriate clinical management. This is illustrated with a few example patients. We cannot propose a generally applicable algorithm with fixed cut-offs, because (as with any risk model) this depends on the specific clinical setting in which the model will be used. Nevertheless, this paper provides a guidance on how the ADNEX model may be adopted into clinical practice

Prevalence of Defecation Disorders and their Symptoms is Comparable in Children and Young Adults:Cross-Sectional Study

Purpose: We aimed to compare the prevalence rates and associated symptoms of constipation and fecal incontinence in children and young adults and evaluate how these patient groups cope with these disorders. Methods: A cross-sectional study was performed in which 212 children (8-17 years) and 149 young adults (18-29 years) from the general Dutch population completed a questionnaire about defecation disorders. Results: Constipation occurred in 15.6% of children and 22.8% of young adults (p=0.55), while the prevalence of fecal incontinence was comparable between groups (7%, p=0.91). The symptoms associated with constipation occurred as often in children as in young adults, while most fecal incontinence symptoms occurred more often in young adults. Approximately 43% of children had constipation for more than 5 years, while 26% of young adults experienced constipation since childhood. Only 27% of constipated children and 21% of constipated young adults received treatment (mostly laxatives). For fecal incontinence, 13% of children and 36% of young adults received treatment (mostly antidiarrheal medications or incontinence pads). Conclusion: In contrast to the general belief, the prevalence of defecation disorders and associated symptoms seem to be comparable in children and young adults. Only a few people with defecation disorders receive adequate treatment

Noble gas geochemistry of fluid inclusions in South African diamonds: implications for the origin of diamond-forming fluids

Fibrous diamond growth zones often contain abundant high-density fluid (HDF) inclusions and these provide the most direct information on diamond-forming fluids. Noble gases are incompatible elements and particularly useful in evaluating large-scale mantle processes. This study further constrains the evolution and origin of the HDFs by combining noble gas systematics with δ13C, N concentrations, and fluid inclusion compositions for 21 individual growth zones in 13 diamonds from the Finsch (n = 3), DeBeers Pool (n = 7), and Koffiefontein (n = 3) mines on the Kaapvaal Craton. C isotope compositions range from −2.8 to −8.6‰ and N contents vary between 268 and 867 at.ppm, except for one diamond with contents of &#60;30 at.ppm N. Nine of the thirteen studied diamonds contained saline HDF inclusions, but the other four diamonds had carbonatitic or silicic HDF inclusions. Carbonatitic and silicic HDFs yielded low He concentrations, R/Ra (3He/4Hesample/3He/4Heair) values of 3.2–6.7, and low 40Ar/36Ar ratios of 390–1940. Noble gas characteristics of carbonatitic-silicic HDFs appear consistent with a subducted sediment origin and interaction with eclogite. Saline HDFs are characterised by high He concentrations, with R/Ra mostly between 3.9 and 5.7, and a wide range in 40Ar/36Ar ratios (389–30,200). The saline HDFs likely originated from subducted oceanic crust with low He but moderate Ar contents. Subsequent interaction of these saline HDFs with mantle peridotite could explain the increase in He concentrations and mantle-like He isotope composition, with the range in low to high 40Ar/36Ar ratios dependent on the initial 36Ar content and extent of lithosphere interaction. The observed negative correlation between 4He contents and R/Ra values in saline HDFs indicates significant in situ radiogenic 4He production

Effect of Proton Diffusion, Electron Conductivity, and Charge-Transfer Resistance on Nickel Hydroxide Discharge Curves

Constant-current discharge curves for the nickel hydroxide electrode are simulated assuming resistances due to diffusion of protons and conduction of electrons through the nickel hydroxide film, and charge-transfer resistance at the film/electrolyte interface contribute to the polarization losses of the electrode. Good qualitative agreement is observed between the model predictions and experimental discharge curves. The results suggest that polarization losses due to diffusional limitations of protons is a critical factor in determining the characteristics of the discharge curve. Ohmic resistance has a significant effect on the discharge curves at the end of discharge, and charge-transfer resistance is a minor contributor to the polarization losses. These findings indicate that accurately measuring the diffusion coefficient of protons, the thickness of the hydroxide film, the initial state-of-charge, and the electronic conductivity as a function of state-of-charge towards the end of discharge are critical in accurately predicting the discharge characteristics of nickel hydroxide. Physical constants which were shown to have minor influence on the discharge curves are the film conductivity at the beginning of discharge, and the exchange current density and cathodic transfer coefficient for the reaction. The time-dependent, one-dimensional diffusion equation has been solved analytically which should provide a computationally efficient means of accounting for proton diffusion and variable electronic conductivity in a macrohomogeneous battery model without sacrificing accuracy