243 research outputs found
Effects of the solid-liquid interface in filter cake formation and consolidation
New data are reported on the formation of filter cakes. Cake formation data are analysed through
two consecutive mechanisms, filtration and consolidation. Process design parameters for each
mechanism are obtained from the models which might allow calculations to be made from small
scale experiments. The magnitude and dependence of the constitutive parameters on pressure,
pH and surface charge, particle size and shape, and the nature of the particle-particle interactions
are shown through the experimental results
Effects of particle surface properties on filter cake formation and consolidation
Data are reported on the formation of filter cakes under pressure where the particles are largely
finer than about 10 μm. The data are analysed through two consecutive mechanisms, filtration
and consolidation. Process design parameters for each mechanism are obtained, which will allow
calculations to be made from small scale experiments. The magnitude and dependence of the
constitutive parameters on pressure, pH, particle size and shape, and the nature of the particleparticle
interactions are shown
Factors affecting the formation and properties of wet compacts
New data are reported on the formation of wet compacts from slurries. The compaction data are
analysed through two consecutive mechanisms, filtration and consolidation. Process design
parameters for each mechanism are obtained from the models which might allow calculations to be
made from small-scale experiments. The magnitude and dependence of the constitutive
parameters on pressure, pH and surface charge, particle size and shape, and the nature of the
particle-particle interactions are shown through the experimental results
Automatic 3D building model generation using deep learning methods based on cityjson and 2D floor plans
In the past decade, a lot of effort is put into applying digital innovations to building life cycles. 3D Models have been proven to be efficient for decision making, scenario simulation and 3D data analysis during this life cycle. Creating such digital representation of a building can be a labour-intensive task, depending on the desired scale and level of detail (LOD). This research aims at creating a new automatic deep learning based method for building model reconstruction. It combines exterior and interior data sources: 1) 3D BAG, 2) archived floor plan images. To reconstruct 3D building models from the two data sources, an innovative combination of methods is proposed. In order to obtain the information needed from the floor plan images (walls, openings and labels), deep learning techniques have been used. In addition, post-processing techniques are introduced to transform the data in the required format. In order to fuse the extracted 2D data and the 3D exterior, a data fusion process is introduced. From the literature review, no prior research on automatic integration of CityGML/JSON and floor plan images has been found. Therefore, this method is a first approach to this data integration
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Comparisons of Limb Structural Properties in Free-Ranging Chimpanzees From Kibale, Gombe, Mahale and Taï Communities
Structural characteristics of limbs bones provide insight into how an animal dynamically loads its limbs during life. Cause-and-effect relationships between loading and the osteogenic response it elicits are complex. In spite of such complexities, cross-sectional geometric properties can be useful indicators of locomotor repertoires. Typical comparisons use primates that are distinguished by broad habitual locomotor differences, usually with samples garnered from several museum collections. Intraspecific variability is difficult to investigate in such samples because behavior or life histories, which are tools for interpreting intraspecific variability, are limited. Clearly intraspecific variation both in morphology and behavior/life history exists. Here we expand an ongoing effort towards understanding intraspecific variation in limb structural properties by comparing free-ranging chimpanzees that have associated behavioral and life history data. Humeral and femoral data from eleven adult chimpanzees (Pan troglodytes) of Kibale National Park (Uganda) are compared to 29 adult habituated chimpanzees from Gombe (Tanzania), Mahale Mountains (Tanzania), and Taï Forest (Côte d’Ivoire) National Park communities. Overall, limb structural morphology of Kibale chimpanzees most resembles limb structural morphology of Mahale chimpanzees. Shape ratios and percentage cortical areas of Kibale chimpanzees are most similar to non-Gombe chimpanzees, while Kibale structural properties (e.g., maximum rigidity) are most similar to non-Taï structural properties. Even after adding Kibale females, Taï females continue to stand out from females in other communities. This research was supported in part by the L.S.B. Leakey Foundation and the National Science Foundation (DDIG, BCS-0002686).Human Evolutionary Biolog
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The context of female dispersal in Kanyawara chimpanzees
In most social mammals, members of either one sex or both leave their natal group at sexual maturity. In catarrhine primates, male emigration is the predominant pattern. Female philopatry facilitates cooperation among kin, and female reproductive success is influenced by these relationships. Chimpanzees (Pan troglodytes) are unusual in that dispersal is almost exclusively by females. While plausible ultimate hypotheses can explain this dispersal pattern, the proximate causes of female dispersal are unknown and warrant examination due to variation in dispersal behaviour and the associated high costs of immigration. In this study, we examine the behavioural and hormonal context of female dispersal in chimpanzees of Kibale National Park, Uganda, in order to understand variation in dispersal patterns and gain insight into functional explanations. Using over 10 years of behavioural, endocrinological, and demographic records, we examined the significance of 5 potential predictors of the timing of dispersal: (1) maturational state; (2) association patterns; (3) mating patterns; (4) physiological stress; and (5) feeding ecology. Female dispersal was not strictly predicted by chronological or gynaecological age, and dispersal did not correlate with shifts in glucocorticoid levels. We found no evidence that females avoided mating in their natal group, even with known relatives, suggesting that inbreeding avoidance is not a sufficient proximate explanation for dispersal in chimpanzees. Instead, variation in social development and the availability of energy for dispersal were implicated and necessitate more intensive examination along with subtler variation in maturational trajectories.Human Evolutionary Biolog
Ultrafast electro-optical disk modulators for logic, communications, optical repeaters, and wavelength converters
We propose a U-shaped pn junction in a silicon-on-insulator microdisk resonator to effectively double the junction–mode overlap in the state-of-the-art, vertical pn junction microdisk electro-optical (EO) modulators. The U-shaped pn junction promotes the maximum overlap between the junction depletion zone and the whispering gallery optical mode in the microdisk. By fully depleting the p region of the npn-sequenced U-junction, the capacitance is reduced below 3 fF, which significantly improves the speed and power performance. In this work, we implement the high-efficiency, depleted U-junction design to maximize the operating bandwidth of EO modulators, EO logic elements, EO 2 × 2 switches for wavelength-division cross-connects, 2 × 2 reconfigurable optical add–drop multiplexers, optical-to-electrical-to-optical (OEO) repeaters-with-gain, OEO wavelength converters, and 2 × 2 optical–optical logic gates. These devices all operate in the 7.6-to-50 GHz bandwidth range with ultralow energy consumption between 0.4 and 9.8 fJ/bit. By using CMOS-compatible materials and fabrication-feasible design dimensions, our proposed high-performance devices offer a promising potential in next-generation, high-volume electro-optical communications and computing circuits
Genotype by environment interactions in identifying cassava (Manihot esculenta Crantz) resistant to cassava brown streak disease
Cassava landraces were evaluated for resistance to cassava brown streak disease (CBSD) for two cropping seasons at a disease hotspot area in Naliendele, Tanzania. Based on reactions to CBSD, several landraces including Chimaje, Mfaransa and Supa B were considered to be resistant to the disease while Kikwada, Mbuyu, and Nyoka were tolerant. ANOVA revealed that the largest sum of squares (SS) (41.9–86.7%) was attributed to the genotype of the cassava landraces, while a smaller proportion of SS (8.1–38.2%) was due to genotype by environment interactions for all traits tested, which included disease symptoms, root weight, number of roots per plant and dry matter content. Environment accounted for the smallest effect (0.01–26.3%), however, the mean squares was nonetheless significant for a few genotypes, which indicated that their disease expression was indeed influenced by the environment. Increased CBSD severity was associated with low temperatures and rainfall. Increased rainfall towards harvesting led to higher root weight but lower dry matter content in the first cropping season. Correlation analysis showed that the presence of CBSD symptoms reduces the amount of usable roots, total root weight, and root dry matter content. Many resistant/tolerant landraces also had high root weight and dry matter content, and they can be used by farmers to reduce CBSD losses. The landraces described here form novel sources of CBSD resistance that can be used for breeding disease-resistant cassava varieties with superior agronomic characteristics
Cardiometabolic health in offspring of women with PCOS compared to healthy controls: a systematic review and individual participant data meta-analysis
BACKGROUND: Women diagnosed with polycystic ovary syndrome (PCOS) suffer from an unfavorable cardiometabolic risk profile, which is already established by child-bearing age. OBJECTIVE AND RATIONALE: The aim of this systematic review along with an individual participant data meta-analysis is to eva
A review of Monte Carlo simulations of polymers with PERM
In this review, we describe applications of the pruned-enriched Rosenbluth
method (PERM), a sequential Monte Carlo algorithm with resampling, to various
problems in polymer physics. PERM produces samples according to any given
prescribed weight distribution, by growing configurations step by step with
controlled bias, and correcting "bad" configurations by "population control".
The latter is implemented, in contrast to other population based algorithms
like e.g. genetic algorithms, by depth-first recursion which avoids storing all
members of the population at the same time in computer memory. The problems we
discuss all concern single polymers (with one exception), but under various
conditions: Homopolymers in good solvents and at the point, semi-stiff
polymers, polymers in confining geometries, stretched polymers undergoing a
forced globule-linear transition, star polymers, bottle brushes, lattice
animals as a model for randomly branched polymers, DNA melting, and finally --
as the only system at low temperatures, lattice heteropolymers as simple models
for protein folding. PERM is for some of these problems the method of choice,
but it can also fail. We discuss how to recognize when a result is reliable,
and we discuss also some types of bias that can be crucial in guiding the
growth into the right directions.Comment: 29 pages, 26 figures, to be published in J. Stat. Phys. (2011
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