Modeling the stress dependence of magnetic hysteresis based on Stoner-Wohlfarth theory

© 2015 IEEE. This paper presents an improved approach for simulating magnetic hysteresis, which takes into account the effect of applied stress, based on an extended Stoner-Wohlfarth (S-W) model. Meanwhile, the S-W asteroid rotates and shrinks, and the stable direction of magnetization of the particle can be calculated from the new energy minimum conditions. This developed model is applied to analyze the magnetic hysteresis phenomenon of a soft magnetic composite (SMC) material under different compaction process, and the results of simulations are in good quantitative agreement with experimental data

Two-dimensional elemental operator for modeling the vectorial hysteresis of soft magnetic composite material

© 2015 IEEE. This paper presents a two-dimensional elemental operator with biaxial anisotropy based on the physical mechanisms of the cubic textured magnetic materials, and deduces an analytical expression of the direct relationship between magnetic field strength H and magnetization M for a single elemental operator by the partial approximate substitutions. To verify the proposed model, the magnetic hysteresis of a soft magnetic composite material SOMALOYTM 500 under alternating excitations was simulated and compared with the experimental results obtained by a 3D magnetic property tester. The results suggest that the proposed approach can be a useful tool in the modeling of vectorial magnetic hysteresis and the calculation of iron loss in practical engineering electromagnetic field analysis

Effects of swim training on the expression of gastrocnemius’ iron transport proteins in rats

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Influence of exercise on iron metabolism

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Identification of aberrant forms of alkaline sphingomyelinase (NPP7) associated with human liver tumorigenesis

Alkaline sphingomyelinase (alk-SMase) is expressed in the intestine and human liver. It may inhibit colonic tumorigenesis, and loss of function mutations have been identified in human colon cancer. The present study investigates its expression in human liver cancer. In HepG2 liver cancer cells, RT–PCR identified three transcripts with 1.4, 1.2 and 0.4 kb, respectively. The 1.4 kb form is the wild-type cDNA with five translated exons, the 1.2 kb product lacks exon 4 and the 0.4 kb form is a combination of exons 1 and 5. Genomic sequence showed that these aberrant transcripts were products of alternative splicing. Transient expression of the 1.2 kb form showed no alk-SMase activity. In HepG2 cells, the alk-SMase activity is low in monolayer condition and increased with cell polarisation. Coexistence of 1.4 and 1.2 kb forms was also identified in one hepatoma biopsy. GenBank search identified a cDNA clone from human liver tumour, which codes a protein containing full length of alk-SMase plus a 73-amino-acid tag at the N terminus. The aberrant form was translated by an alternative starting codon upstream of the wild-type mRNA. Expression study showed that linking the tag markedly reduced the enzyme activity. We also analysed human liver biopsy samples and found relatively low alk-SMase activity in diseases with increased risk of liver tumorigenesis. In conclusion, expression of alk-SMase is changed in hepatic tumorigenesis, resulting in loss or marked reduction of the enzyme function

Security challenges of small cell as a service in virtualized mobile edge computing environments

Research on next-generation 5G wireless networks is currently attracting a lot of attention in both academia and industry. While 5G development and standardization activities are still at their early stage, it is widely acknowledged that 5G systems are going to extensively rely on dense small cell deployments, which would exploit infrastructure and network functions virtualization (NFV), and push the network intelligence towards network edges by embracing the concept of mobile edge computing (MEC). As security will be a fundamental enabling factor of small cell as a service (SCaaS) in 5G networks, we present the most prominent threats and vulnerabilities against a broad range of targets. As far as the related work is concerned, to the best of our knowledge, this paper is the first to investigate security challenges at the intersection of SCaaS, NFV, and MEC. It is also the first paper that proposes a set of criteria to facilitate a clear and effective taxonomy of security challenges of main elements of 5G networks. Our analysis can serve as a staring point towards the development of appropriate 5G security solutions. These will have crucial effect on legal and regulatory frameworks as well as on decisions of businesses, governments, and end-users

Laboratory toxicity studies demonstrate no adverse effects of Cry1Ab and Cry3Bb1 to larvae of Adalia bipunctata (Coleoptera: Coccinellidae): the importance of study design

Scientific studies are frequently used to support policy decisions related to transgenic crops. Schmidt et al., Arch Environ Contam Toxicol 56:221–228 (2009) recently reported that Cry1Ab and Cry3Bb were toxic to larvae of Adalia bipunctata in direct feeding studies. This study was quoted, among others, to justify the ban of Bt maize (MON 810) in Germany. The study has subsequently been criticized because of methodological shortcomings that make it questionable whether the observed effects were due to direct toxicity of the two Cry proteins. We therefore conducted tritrophic studies assessing whether an effect of the two proteins on A. bipunctata could be detected under more realistic routes of exposure. Spider mites that had fed on Bt maize (events MON810 and MON88017) were used as carriers to expose young A. bipunctata larvae to high doses of biologically active Cry1Ab and Cry3Bb1. Ingestion of the two Cry proteins by A. bipunctata did not affect larval mortality, weight, or development time. These results were confirmed in a subsequent experiment in which A. bipunctata were directly fed with a sucrose solution containing dissolved purified proteins at concentrations approximately 10 times higher than measured in Bt maize-fed spider mites. Hence, our study does not provide any evidence that larvae of A. bipunctata are sensitive to Cry1Ab and Cry3Bb1 or that Bt maize expressing these proteins would adversely affect this predator. The results suggest that the apparent harmful effects of Cry1Ab and Cry3Bb1 reported by Schmidt et al., Arch Environ Contam Toxicol 56:221–228 (2009) were artifacts of poor study design and procedures. It is thus important that decision-makers evaluate the quality of individual scientific studies and do not view all as equally rigorous and relevant

Von Bezold assimilation effect reverses in stereoscopic conditions

Lightness contrast and lightness assimilation are opposite phenomena: in contrast, grey targets appear darker when bordering bright surfaces (inducers) rather than dark ones; in assimilation, the opposite occurs. The question is: which visual process favours the occurrence of one phenomenon over the other? Researchers provided three answers to this question. The first asserts that both phenomena are caused by peripheral processes; the second attributes their occurrence to central processes; and the third claims that contrast involves central processes, whilst assimilation involves peripheral ones. To test these hypotheses, an experiment on an IT system equipped with goggles for stereo vision was run. Observers were asked to evaluate the lightness of a grey target, and two variables were systematically manipulated: (i) the apparent distance of the inducers; and (ii) brightness of the inducers. The retinal stimulation was kept constant throughout, so that the peripheral processes remained the same. The results show that the lightness of the target depends on both variables. As the retinal stimulation was kept constant, we conclude that central mechanisms are involved in both lightness contrast and lightness assimilation

New chemolysis for urological calcium phosphate calculi – a study in vitro

BACKGROUND: Advances in techniques have left very few indications for open surgical extraction of urinary stones currently. These advances notwithstanding, the search continues for medical approaches to urinary stone management. In this study, we perform an in vitro study analyzing the efficiency and prospect of two new complex solutions in urological calcium phosphate calculi dissolution. METHODS: Eighteen stones composed mainly of calcium phosphates were taken from patients who underwent kidney stone surgery. These stones were large enough (weight range 0.514–0.928 g) to be fragmented and matched equally into six groups. Chemolysis of phosphate stones was done with six different solvents and was repeated 3 times with 6 stones for each solution. At 24, 48 and 72 h, reduction in weight, percentage weight change, and dissolution rate; the dissolution rates at pH 5.0, 7.0 and 8.5 for each solution, using different cations (Na(+), K(+ )or Ca(2+)), according to different dilutions (1:1, 1:2, 1:3, 1:4) of S1 and S2 were simultaneously determined. RESULTS: Calcium phosphate calculi were poorly dissolved by Phys and Art, and they had a low dissolution rate in pH 8.5 EDTA. The most effective solutions were S1, S2 and R, with 72 h mean dissolution rates: 5.75 ± 0.44 mg/hr (S1), 5.2 ± 0.63 mg/hr (S2), 4.55 ± 0.46 mg/hr (R) ([Image: see text] ± s, p < 0.01 R, S1 and S2 vs Phys, Art and EDTA; p < 0.05, S1 vs R, LSD-test). The mean percentage weight loss at 72 h was: 52.1 ± 15.75 % (S1), 44.4 ± 7.37 % (S2) and 40.5 ± 3.67 % (R) ([Image: see text] ± s, p < 0.01 R, S1 and S2 vs Phys, Art and EDTA, LSD-test). Diluted twice, S1 and S2 had even better effectiveness than their initial solution. The additive of Na(+), K(+ )or Ca(2+ )greatly reduced the dissolution rates of S1, S2. CONCLUSION: Our data indicate that test solutions S1 and S2 are effective solvents in the chemolysis of calcium phosphate stones. At twice dilutions, these solutions are even more useful in the treatment of stone disease