881 research outputs found
Leveraging Lean in construction: A case study of a BIM-based HVAC manufacturing process
The impetus towards efficiency in the AECO (Architecture, Engineering, Construction & Operations) sector is driving the implementation of Lean practices. BIM technologies and BIM processes provide methods by which this can be achieved. Major clients of building services contractors have begun to mandate the use of BIM and some are using BIM preparedness/experience as pre-tender qualification criteria. In this case study, an initial review has been conducted of the achievements of a major Irish M&E contractor in implementing BIM. The firm purpose-built a facility for the off-site manufacture of building services components. The operations of the plant are efficient and qualityassured through the use of an appropriately skilled workforce at all stages of manufacture, and tracking software that has developed as the knowledge of the contractor grew. Standardised processes have been developed which have resulted in greater efficiencies and lower costs for the contractor as a result of fewer requirements for onsite modifications (such as those caused by clashes), less waste, and greater flexibility. Despite some initial objections, the employees of the company are now more satisfied with their working conditions and are, as a result, more productive. Through investment in BIM-based, Lean processes, the contractor can now better compete when tenerding for large-scale projects in Ireland and worldwide, including the rapidly-increasing number where BIM experience and preparedness is mandated
Converting dark matter to dark radiation does not solve cosmological tensions
Tensions between cosmological parameters (in particular the local expansion
rate and the amplitude of matter clustering ) inferred from
low-redshift data and data from the cosmic microwave background (CMB) and
large-scale structure (LSS) experiments have inspired many extensions to the
standard cosmological model, CDM. Models which simultaneously lessen
both tensions are of particular interest. We consider one scenario with the
potential for such a resolution, in which some fraction of the dark matter has
converted into dark radiation since the release of the CMB. Such a scenario
encompasses and generalizes the more standard "decaying dark matter" model,
allowing additional flexibility in the rate and time at which the dark matter
converts into dark radiation. In this paper, we constrain this scenario with a
focus on exploring whether it can solve (or reduce) these tensions. We find
that such a model is effectively ruled out by low- CMB data, in
particular by the reduced peak-smearing due to CMB lensing and the excess
Integrated Sachs--Wolfe (ISW) signal caused by the additional dark energy
density required to preserve flatness after dark matter conversion into dark
radiation. Thus, such a model does not have the power to reduce these tensions
without further modifications. This conclusion extends and generalizes related
conclusions derived for the standard decaying dark matter model.Comment: 19 pages, 8 figures. Our modified Boltzmann code is available at
https://github.com/fmccarthy/class_DMDR Re-uploaded with some more details on
the failure of the DMDR model (v2); Reuploaded with the version published by
PRD (v3
Component-separated, CIB-cleaned thermal Sunyaev--Zel'dovich maps from PR4 data with a flexible public needlet ILC pipeline
We use the full-mission PR4 data to construct maps of the
thermal SunyaevZel'dovich effect (Compton- parameter) in our Universe.
To do so, we implement a custom needlet internal linear combination (NILC)
pipeline in a Python package, , which we make publicly
available. We publicly release our Compton- maps, which we construct using
various constrained ILC ("deprojection") options in order to minimize
contamination from the cosmic infrared background (CIB) in the reconstructed
signal. In particular, we use a moment-based deprojection which minimizes
sensitivity to the assumed frequency dependence of the CIB. Our code
performs needlet or harmonic ILC on mm-wave sky maps in a
flexible manner, with options to deproject various components on all or some
scales. We validate our maps and compare them to the official
2015 -map, finding that we obtain consistent results on large scales and
10-20 lower noise on small scales. We expect that these maps will be useful
for many auto- and cross-correlation analyses; in a companion paper, we use
them to measure the tSZ -- CMB lensing cross-correlation. We anticipate that
will be useful both for data analysis and for pipeline
validation on simulations to understand the propagation of foreground
components through a full NILC pipeline.Comment: 28 pages, 15 figures. Public maps and other data products are
available at https://users.flatironinstitute.org/~fmccarthy/ymaps_PR4_McCH23/
; public code is available at https://github.com/jcolinhill/pyilc . V2: some
additional notes about the effective CIB SED parameters and the halo model,
also removed discussion about apodization of our maps and Planck map
The Engineers' Bookshelf
Our perception of an object’s size arises from the integration of multiple sources of visual information including retinal size, perceived distance and its size relative to other objects in the visual field. This constructive process is revealed through a number of classic size illusions such as the Delboeuf Illusion, the Ebbinghaus Illusion and others illustrating size constancy. Here we present a novel variant of the Delbouef and Ebbinghaus size illusions that we have named the Binding Ring Illusion. The illusion is such that the perceived size of a circular array of elements is underestimated when superimposed by a circular contour – a binding ring – and overestimated when the binding ring slightly exceeds the overall size of the array. Here we characterize the stimulus conditions that lead to the illusion, and the perceptual principles that underlie it. Our findings indicate that the perceived size of an array is susceptible to the assimilation of an explicitly defined superimposed contour. Our results also indicate that the assimilation process takes place at a relatively high level in the visual processing stream, after different spatial frequencies have been integrated and global shape has been constructed. We hypothesize that the Binding Ring Illusion arises due to the fact that the size of an array of elements is not explicitly defined and therefore can be influenced (through a process of assimilation) by the presence of a superimposed object that does have an explicit size
Third molar surgery: the patient's and the clinician's perspective
BACKGROUND: In this report, the problems of third molar surgery have been reviewed from the perspective of both patient and clinician; additionally an overall analysis of preoperative imaging investigations was carried out.Specifically, three main areas of interest were investigated: the prediction of surgical difficulty and potential complications; the assessment of stress and anxiety and finally the assessment of postoperative complications and the surgeon's experience. FINDINGS: In the first study, the prediction of surgical difficulty and potential injury to the inferior alveolar nerve was assessed. This was achieved by examining the patient's orthopantomograms and by using the Pederson Difficulty Index (PDI). Several radiological signs were identified and a classification tree was created to help predict the incidence of such event.In the second study, a prospective assessment addressing the patient's stress and anxiety pre-, intra- and postoperatively was employed. Midazolam was the active drug used against placebo. Objective and subjective parameters were assessed, including measuring the cortisol level in saliva. Midazolam was found to significantly reduce anxiety levels and salivary cortisol was identified as an accurate anxiety marker.In the third study, postoperative complications and the surgeon's experience were examined. Few patients in this study suffered permanent nerve dysfunction. Junior surgeons reported a higher complication rate particularly in trismus, alveolar osteitis, infection and paraesthesia over the distributions of the inferior alveolar and lingual nerves. In apparent contrast, senior surgeons reported higher incidence of postoperative bleeding. DISCUSSION: These studies if well employed can lead to favourable alteration in patient management and might have a positive impact on future healthcare service
A novel powder-epoxy towpregging line for wind and tidal turbine blades
A novel material and process was developed using fibre-reinforced powder-epoxy to produce unidirectional towpreg with a pilot-scale towpregging line, for cost-effective production of large composite structures for the renewable energy market, specifically for wind and tidal turbine blades. Electrostatic attraction was used to coat fibre tows with powder epoxy and either joule or radiant heating employed to heat and melt the polymer, followed by consolidation between rollers. Unidirectional carbon-fibre and basalt-fibre reinforced polymer laminates (UD-CFRP and UD-BFRP, respectively) were manufactured from the towpreg. Tensile test results showed that the towpregging process could be employed to achieve high performance UD-CFRP with 0° tensile properties that are similar or better than commercially-available UD-CFRP systems. The competitive advantages of the powder-epoxy towpreg system include lower cost, better overall manufacturing control for vacuum-bag-only manufacturing and the ability to co-cure parts together at a later stage. Mechanical test results showed some variation between two types of UD-BFRP, but the results compared well with published data on UD-BFRP and equivalent glass-fibre reinforced polymer (GFRP) systems. Finally, the influence of hygrothermal ageing due to water immersion on the tensile properties of the materials was investigated, with tests revealing that the water ageing effect was more severe in the case of UD-BFRP than for UD-CFRP
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Comparison of Two Aspergillus oryzae Genomes From Different Clades Reveals Independent Evolution of Alpha-Amylase Duplication, Variation in Secondary Metabolism Genes, and Differences in Primary Metabolism
Microbes (bacteria, yeasts, molds), in addition to plants and animals, were domesticated for their roles in food preservation, nutrition and flavor. Aspergillus oryzae is a domesticated filamentous fungal species traditionally used during fermentation of Asian foods and beverage, such as sake, soy sauce, and miso. To date, little is known about the extent of genome and phenotypic variation of A. oryzae isolates from different clades. Here, we used long-read Oxford Nanopore and short-read Illumina sequencing to produce a highly accurate and contiguous genome assemble of A. oryzae 14160, an industrial strain from China. To understand the relationship of this isolate, we performed phylogenetic analysis with 90 A. oryzae isolates and 1 isolate of the A. oryzae progenitor, Aspergillus flavus. This analysis showed that A. oryzae 14160 is a member of clade A, in comparison to the RIB 40 type strain, which is a member of clade F. To explore genome variation between isolates from distinct A. oryzae clades, we compared the A. oryzae 14160 genome with the complete RIB 40 genome. Our results provide evidence of independent evolution of the alpha-amylase gene duplication, which is one of the major adaptive mutations resulting from domestication. Synteny analysis revealed that both genomes have three copies of the alpha-amylase gene, but only one copy on chromosome 2 was conserved. While the RIB 40 genome had additional copies of the alpha-amylase gene on chromosomes III, and V, 14160 had a second copy on chromosome II and an third copy on chromosome VI. Additionally, we identified hundreds of lineage specific genes, and putative high impact mutations in genes involved in secondary metabolism, including several of the core biosynthetic genes. Finally, to examine the functional effects of genome variation between strains, we measured amylase activity, proteolytic activity, and growth rate on several different substrates. RIB 40 produced significantly higher levels of amylase compared to 14160 when grown on rice and starch. Accordingly, RIB 40 grew faster on rice, while 14160 grew faster on soy. Taken together, our analyses reveal substantial genome and phenotypic variation within A. oryzae
Systematic screening of 96 Schistosoma mansoni cell-surface and secreted antigens does not identify any strongly protective vaccine candidates in a mouse model of infection.
Background: Schistosomiasis is a major parasitic disease affecting people living in tropical and sup-tropical areas. Transmission of the parasite has been reported in 78 countries, causing significant morbidity and around 200,000 deaths per year in endemic regions. The disease is currently managed by the mass-administration of praziquantel to populations at risk of infection; however, the reliance on a single drug raises the prospect of parasite resistance to the only treatment widely available. The development of an effective vaccine would be a more powerful method of control, but none currently exists and the identification of new immunogens that can elicit protective immune responses therefore remains a priority. Because of the complex nature of the parasite life cycle, identification of new vaccine candidates has mostly relied on the use of animal models and on a limited set of recombinant proteins. Methods: In this study, we have established an infrastructure for testing a large number of vaccine candidates in mice and used it to screen 96 cell-surface and secreted recombinant proteins from Schistosoma mansoni. This approach, using standardised immunisation and percutaneous infection protocols, allowed us to compare an extensive set of antigens in a systematic manner. Results: Although some vaccine candidates were associated with a statistically significant reduction in the number of eggs in the initial screens, these observations could not be repeated in subsequent challenges and none of the proteins studied were associated with a strongly protective effect against infection. Conclusions: Although no antigens individually induced reproducible and strongly protective effects using our vaccination regime, we have established the experimental infrastructures to facilitate large-scale systematic subunit vaccine testing for schistosomiasis in a murine infection model. Copyright: © 2019 Crosnier C et al
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