Numerical analysis of hot deep drawing of din 27MNCRB5 steel sheets under controlled stretching

Hot stamping has been widely studied and increasingly applied in the automotive industry. This process is characterized by its ability to stamp high strength steels, yielding products with high mechanical strength, thus reducing the weight of stamped components and therefore the vehicles weight. It also demands less energy because steel sheets are heated by induction, more efficient than electric furnaces. With controlled stretching it is possible to manufacture thinner stamped parts with high mechanical strength, therefore it is necessary to know the formability limits to prevent failure and achieve the largest possible thickness reduction. In this work the hot formability of DIN 27MnCrB5 steel sheets under stretching conditions was evaluated by numerical simulation with the finite element software Forge2008. The numerical results were compared to experimental results. Initially hot tensile tests were simulated to define the strain rate in different regions of the sample and to evaluate the deformation at fracture. For tests at 700, 800 and 900ºC it was found that the strain rates vary from 0.01 to 0.5 s-1. Experimental tensile tests were also carried out with the same conditions as simulated. Both simulation and experiments presented very similar results for the ultimate tensile strength, and therefore it was possible to assume the experimental fracture strain as a consistent input for the numerical models. With the results of the tensile tests, hot Nakazima tests were simulated to evaluate the highest dome which could be formed without failure risks caused by sheet thickness thinning. The simulation results were validated by experimental tests, and as a result, a new numerical strategy was elaborated to define the hot formability based on the plastic instability and necking localization as a function of the stamping temperature and blank dimensions

Development of a second generation prototype reflectometer for reflectance measurement in space Final technical report

Prototype reflectometer development for reflection measurements in spac

Mucus Hyperconcentration as a Unifying Aspect of the Chronic Bronchitic Phenotype

Abnormalities in mucus production and qualitative properties such as mucus hydration are central to the pathophysiology of airway disease including cystic fibrosis, asthma, and chronic bronchitis. In vitro air–liquid interface epithelial cell cultures demonstrate direct relationships between mucociliary transport, periciliary liquid (PCL) height, and mucus concentration (expressed as percent solids or partial osmotic pressure). In health, the osmotic modulus/pressure of the PCL exceeds that of the mucus layer, resulting in efficient, low-friction movement of mucus. In disease, through multiple mechanisms, the osmotic pressure of the mucus begins to exceed basal PCL values, resulting in compression of the cilia and slowing of mucus transport. The in vivo data in both cystic fibrosis and chronic bronchitis parallel in vitro data demonstrating that when mucus osmotic pressure is increased, mucociliary clearance is decreased. In chronic bronchitis, there is a direct correlation between FEV1 and percent solids of mucus, demonstrating a strong relationship between disease progression and mucus abnormalities. Animal models, based mechanistically on raised sodium absorption (and therefore water absorption) from airway surfaces, mimic the pathophysiology of chronic obstructive pulmonary disease. Collectively, these data suggest the importance of mucus concentration in the pathogenesis of airway disease. It is important to understand the precise mechanisms that result in mucus hyperconcentration, for example, mucin overproduction versus abnormal regulation of ion/water transport, which may be unique to and characteristic of each disease phenotype. The measurement of mucus concentration may be a simple method to diagnose chronic bronchitis, monitor its progression, and serve as a biomarker for development of new therapies

On the poverty of a priorism: technology, surveillance in the workplace and employee responses

Many debates about surveillance at work are framed by a set of a priori assumptions about the nature of the employment relationship that inhibits efforts to understand the complexity of employee responses to the spread of new technology at work. In particular, the debate about the prevalence of resistance is hamstrung from the outset by the assumption that all apparently non-compliant acts, whether intentional or not, are to be counted as acts of resistance. Against this background this paper seeks to redress the balance by reviewing results from an ethnographic study of surveillance-capable technologies in a number of British workplaces. It argues for greater attention to be paid to the empirical character of the social relations at work in and through which technologies are deployed and in the context of which employee responses are played out

Where Lies the Land?

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A simple proof of the Markoff conjecture for prime powers

We give a simple and independent proof of the result of Jack Button and Paul Schmutz that the Markoff conjecture on the uniqueness of the Markoff triples (a,b,c), where a, b, and c are in increasing order, holds whenever $c$ is a prime power.Comment: 5 pages, no figure

An Examination of the Characteristics and Perceptions of School Resource Officers in Rural and Urban Oklahoma Schools

Fueled by concerns about school violence, the number of School Resource Officers (SROs) in the United States has soared. SROs are law enforcement officers who work in elementary and secondary schools and who are tasked to increase school safety. As of 2016, 48 percent of US public schools had SROs, compared to less than one percent in the 1970s, yet there are few studies that measure their effects. In particular, the literature largely ignores rural/urban differences. This study uses survey data from SROs working in public schools in Oklahoma to understand their roles and to determine if there are differences between rural and urban SROs. We look at jurisdiction and school characteristics as well as SRO perceptions of disciplinary practices, school climate, referrals, and community involvement. Identifying variability in these areas is a requisite first step in understanding the effect of the SRO on school safety

Applications of p-deficiency and p-largeness

We use Schlage-Puchta's concept of p-deficiency and Lackenby's property of p-largeness to show that a group having a finite presentation with p-deficiency greater than 1 is large, which implies that Schlage-Puchta's infinite finitely generated p-groups are not finitely presented. We also show that for all primes p at least 7, any group having a presentation of p-deficiency greater than 1 is Golod-Shafarevich, and has a finite index subgroup which is Golod-Shafarevich for the remaining primes. We also generalise a result of Grigorchuk on Coxeter groups to odd primes.Comment: 23 page

Nanotechnology in multimodal theranostic capsule endoscopy

Video capsule endoscopy (VCE) has become a clinically accepted diagnostic modality in the last 20 years and has established a technological roadmap for other capsule endoscopy (CE) devices, incorporating microscale technology, a local power supply and wireless communication. However, VCE does not provide a therapeutic function and research in therapeutic capsule endoscopy (TCE) has been limited. This paper proposes a new route towards viable TCE based on multiple CE devices including essential nanoscale components. A first device is used for multimodal diagnosis, with quantitative microultrasound as a complement to video imaging. Ultrasound-enhanced fluorescent marking of sites of pathology allows follow-up with a second device for therapy. This is based on fluorescence imaging and ultrasound-mediated targeted drug delivery. Subsequent treatment verification and monitoring with a third device exploits the minimally invasive nature of CE. Clinical implementation of a complete patient pathway remains the subject of research but several key components have been prepared in early prototype form. These are described, along with gaps that remain to be filled

Predicting Functional and Regulatory Divergence of a Drug Resistance Transporter Gene in the Human Malaria Parasite

Background: The paradigm of resistance evolution to chemotherapeutic agents is that a key coding mutation in a specific gene drives resistance to a particular drug. In the case of resistance to the anti-malarial drug chloroquine (CQ), a specific mutation in the transporter pfcrt is associated with resistance. Here, we apply a series of analytical steps to gene expression data from our lab and leverage 3 independent datasets to identify pfcrt-interacting genes. Resulting networks provide insights into pfcrt’s biological functions and regulation, as well as the divergent phenotypic effects of its allelic variants in different genetic backgrounds. Results: To identify pfcrt-interacting genes, we analyze pfcrt co-expression networks in 2 phenotypic states - CQ-resistant (CQR) and CQ-sensitive (CQS) recombinant progeny clones - using a computational approach that prioritizes gene interactions into functional and regulatory relationships. For both phenotypic states, pfcrt co-expressed gene sets are associated with hemoglobin metabolism, consistent with CQ’s expected mode of action. To predict the drivers of co-expression divergence, we integrate topological relationships in the co-expression networks with available high confidence protein-protein interaction data. This analysis identifies 3 transcriptional regulators from the ApiAP2 family and histone acetylation as potential mediators of these divergences. We validate the predicted divergences in DNA mismatch repair and histone acetylation by measuring the effects of small molecule inhibitors in recombinant progeny clones combined with quantitative trait locus (QTL) mapping. Conclusions: This work demonstrates the utility of differential co-expression viewed in a network framework to uncover functional and regulatory divergence in phenotypically distinct parasites. pfcrt-associated co-expression in the CQ resistant progeny highlights CQR-specific gene relationships and possible targeted intervention strategies. The approaches outlined here can be readily generalized to other parasite populations and drug resistances