Expandable takeup reel facilitates paper tape removal

Takeup reel receives continuous paper tapes from data recording machines. The roller is recessed to have four longitudinal members about its periphery which can be extended or retracted to change the overall diameter of the assembly to allow easy removal of the tapes

Spatial and temporal patterns of carabid activity-density in cereals do not explain levels of predation on weed seeds

Seed predation is an important component of seed mortality of weeds in agro-ecosystems, but the agronomic use and management of this natural weed suppression is hampered by a lack of insight in the underlying ecological processes. In this paper, we investigate whether and how spatial and temporal variation in activity-density of granivorous ground beetles (Coleoptera: Carabidae) results in a corresponding pattern of seed predation. Activity-density of carabids was measured by using pitfall traps in two organic winter wheat fields from March to July 2004. Predation of seeds (Capsella bursa-pastoris, Lamium amplexicaule, Poa annua and Stellaria media) was assessed using seed cards at the same sites and times. As measured by pitfall traps, carabids were the dominant group of insects that had access to the seed cards. In the field, predation of the four different species of seed was in the order: C. bursa-pastoris>P. annua>S. media>L. amplexicaule; and this order of preference was confirmed in the laboratory using the dominant species of carabid. On average, seed predation was higher in the field interior compared to the edge, whereas catches of carabids were highest near the edge. Weeks with elevated seed predation did not concur with high activity-density of carabids. Thus, patterns of spatial and temporal variation in seed predation were not matched by similar patterns in the abundance of granivorous carabid beetles. The lack of correspondence is ascribed to effects of confounding factors, such as weather, the background density of seeds, the composition of the carabid community, and the phenology and physiological state of the beetles. Our results show that differences in seed loss among weed species may be predicted from laboratory trials on preference. However, predator activity-density, as measured in pitfall traps, is an insufficient predictor of seed predation over time and space within a fiel

Bomen over ruimte: een studie naar de toekomstige ruimtebehoefte voor de boomteelt in de regio Boskoop

In het kader van de streekplanherziening Zuid-Holland Oost is een schatting gemaakt van de toekomstige ruimtebehoefte voor de boomteelt in de regio Boskoop tot 2015. Op basis van toekomstige ontwikkelingen in de vraag naar boomteeltproducten, de (inter)nationale concurrentiepositie van de boomteelt in de regio Boskoop en de bedrijfsstructuur is de extra ruimtebehoefte geschat op 2% per jaar. Het totale areaal boomteelt in 2015 komt hiermee op 1.435 ha (+ 335 ha), waarvan de helft pot- en containerteelt en de helft in de vollegrond. Ook zal tot 2015 de teelt onder glas gestaag toenemen. Om het boomteeltcentrum in de regio Boskoop in stand te houden is niet alleen behoefte aan extra ruimte, maar zal ook voldaan moeten worden aan een aantal kwalitatieve randvoorwaarden. De belangrijkste randvoorwaarden zijn: planologische zekerheid, ruimte voor ondersteunend glas, goede bedrijfsstructuur, goede infrastructuur, kwalitatief goed opgeleid personeel en professioneel ondernemersscha

Scheppen van ruimte : maatschappelijke ontwikkelingen en verkenning 'zoutwaterkas' : Research Guidance de rode draad bij systeeminnovaties

Zoutwaterlandbou

Feeding and growth of a dyke-laccolith system (Elba Island, Italy) from AMS and mineral fabric data

Dykes feed laccoliths and sills; however, the link between feeder and intrusion is rarely observed. The felsic San Martino laccolith displays a clear feeder–intrusion link, allowing reconstruction of the influence of the size and location of feeder dykes on magma flow during formation of subhorizontal intrusions. This work uses anisotropy of magnetic susceptibility (AMS) combined with mineral shape-preferred orientations of sanidine megacrysts to examine magma flow pathways through feeders into a laccolith. Strong correlation between AMS and K-feldspar datasets indicates that alteration affecting the paramagnetic mineralogy did not influence AMS results. The well-established field relationships between feeder and laccolith provided a robust ‘geo-logical’ model for flow pathways that we have used as a framework to aid interpretation of AMS data. The position and size of the main feeder dyke helped to predict the flow paths in the overlying laccolith. Our results show that magma spread laterally from the feeding system and built the laccolith layers with propagating and inflating divergent flow where tabular particles became aligned perpendicular to the magma displacement direction. The lack of internal discontinuities indicates that the magma was injected as a single pulse or a series of quickly coalescing pulses

Optimization-based reference calculation for Modular Multilevel Converters in balanced and unbalanced network conditions

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper addresses an optimization-based algorithm to calculate the references of the Modular Multilevel Converter (MMC) during normal and constrained scenarios (when the prioritization of quantities is required). The optimization problem prioritizes to satisfy the positive- and negative-sequence active and reactive current set-points demanded by the Transmission System Operator (TSO) through the corresponding grid code. If the TSO’s requirements are achieved, the algorithm minimizes the arm impedances losses. Otherwise, it attempts to reduce the error between the current components and the TSO’s current set-points. The optimization-based current reference calculation is derived based on the steady-state equations of the MMC, considering the maximum currents that can flow through the MMC’s arms, the maximum and minimum arm applied voltages and the maximum sub-module capacitor’s voltage. Simulation in the time-domain have been conducted and the results indicate that this method can be potentially employed to calculate the converter’s references during both normal and faulted conditions.Peer ReviewedPostprint (author's final draft

Improved current reference calculation for MMCs internal energy balancing control

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper addresses an improved inner current reference calculation to be employed in the control of modular multilevel converters operating during either balanced or unbalanced conditions. The suggested reference calculation is derived based on the AC and DC additive and differential voltage components applied to the upper and lower arms of the converter. In addition, the impacts caused not only by the AC networks impedances but also by the MMCs arm impedances are also considered during the derivation of the AC additive current reference expressions. Another issue discussed in this article regards that singular voltage conditions, where the positive-sequence component is equal to the negative one, may occur not only in the AC network but also internally (within the converters applied voltages). Several different inner current reference calculation methods are compared and their applicability during the former fault conditions is analyzed. The paper presents a detailed formulation of the inner current reference calculation and applies it to different unbalanced AC grid faults where it is shown that the presented approach can be potentially used to maintain the internal energy of the converter balanced during normal and fault conditions.Peer ReviewedPostprint (author's final draft

Intuitive learnability of touch gestures for technology-naïve older adults

Touch-based interactions, if intuitive and natural, should be highly learnable. However, the learnability of touch gestures as a computer interaction modality cannot be taken for granted and should be evaluated empirically. This is especially true when technology-naïve older adults are concerned, given the psychological and physical constraints associated with this age range. To investigate this issue, we conducted a study with 17 technology-naïve older adults, whose experience with technology was mostly limited to making calls with mobile phones. Specifically, the participants were presented with three simple digital games on an interactive tabletop surface and asked to play the games on their own with minimal instruction or help. The first two games required the use of a drag gesture whereas the third game required the use of a rotate gesture. The main research question was whether the older adults could learn the gestures effectively and efficiently. A set of variables such as task duration and gesture accuracy were measured. Results showed that the learnability of a drag gesture was relatively high and that the participants could transfer this skill across the games. In contrast, the learnability of a rotate gesture was low and most of the participants failed to demonstrate any improvement over the tasks of the game. These findings partially corroborate those of earlier work. Implications for future work are drawn, especially exploring the potential of social interactions between older adults for enhancing the learning effects

Deploying Big Data To Crack The Genotype To Phenotype Code

Mechanistically connecting genotypes to phenotypes is a longstanding and central mission of biology. Deciphering these connections will unite questions and datasets across all scales from molecules to ecosystems. Although high-throughput sequencing has provided a rich platform on which to launch this effort, tools for deciphering mechanisms further along the genome to phenome pipeline remain limited. Machine learning approaches and other emerging computational tools hold the promise of augmenting human efforts to overcome these obstacles. This vision paper is the result of a Reintegrating Biology Workshop, bringing together the perspectives of integrative and comparative biologists to survey challenges and opportunities in cracking the genotype to phenotype code and thereby generating predictive frameworks across biological scales. Key recommendations include: promoting the development of minimum “best practices” for the experimental design and collection of data; fostering sustained and long-term data repositories; promoting programs that recruit, train, and retain a diversity of talent and providing funding to effectively support these highly cross-disciplinary efforts. We follow this discussion by highlighting a few specific transformative research opportunities that will be advanced by these efforts

Embryopathic Effects of Waterborne and Sediment-Accumulated Cadmium, Mercury and Zinc on Reproduction and Survival of Fish and Amphibian Populations in Kentucky

Fish and amphibian egg cultures were used to determine the embryopathic effects of cadmium, mercury, and zinc released from natural and metal-enriched sediments, and to develop egg culture bioassay procedures suitable for monitoring bottom sediments for hazardous contaminants. Eggs of the narrow-mouthed toad (Gastrophryne carolinensis), goldfish (Carassius auratus), and rainbow trout (Salmo gairdnei) were cultured in contaminant-free water added to natural and metal-enriched sediments. Exposure was initiated after fertilization (toad, goldfish) or at 10 days prehatching (trout) and maintained continuously through 4-10 days posthatching. Sediments were enriched with 0.1-100 ppm cadmium and mercury and 1.0-1000 ppm zinc. Natural control sediments contained average concentrations of 0.052 ppm mercury, 1.0 ppm cadmium, and 108.2 ppm zinc. Substantial frequencies of mortality and teratogenesis occurred for all 3 animal species when eggs were cultured over natural elements further enriched with as little as 0.1-1.0 ppm cadmium or mercury and 1-10ppm zinc. Survival of trout embryos and alevins closely paralleled sediment test concentrations. The sediment TL50 concentrations for trout stages cultured from 10 days prehatching through 10 days posthatching were approximately 1ppm for mercury, 2.15 ppm for cadmium, and 210.6 ppm for zinc. Sediment metals were substantially more lethal to eggs and embryos than to free-living larvae or fry