Finite element algorithms for the static and dynamic analysis of time-dependent and time-independent plastic bodies

Includes bibliographical references.Continuum and finite element formulations of the static and dynamic initial-boundary value evolution (elastoplastic) problems are considered in terms of both the classical and internal variable frameworks. The latter framework is employed to develop algorithms in the form of convex mathematical programming and Newton-Raphson schemes. This latter scheme is shown to be linked to the former in the sense that it expresses the conditions under which the convex non-linear function can be minimised. A Taylor series expansion in time and space is extensively employed to derive integration schemes which include the generalised trapezoidal rule and a generalised Newton-Raphson scheme. This approach provides theoretical foundations for the generalised trapezoidal rule and the generalised Newton-Raphson scheme that have some geometrical insights as well as an interpretation in terms of finite differences and calculus. Conventionally, one way of interpreting the generalised trapezoidal rule is that it uses a weighted average of values (such as velocity or acceleration) at the two ends of the time interval. In this dissertation, the generalised trapezoidal scheme is shown to be a special case of the forward-backward difference scheme for solving first order differential equations

Competitive swimmers modify racing start depth upon request

To expand upon recent findings showing that competitive swimmers complete significantly shallower racing starts in shallower pools, 12 more experienced and 13 less experienced swimmers were filmed underwater during completion of competitive starts. Two starts (1 routine and 1 “requested shallow”) were executed from a 0.76 m block height into water 3.66 m deep. Dependent measures were maximum head depth, head speed at maximum head depth, and distance from the starting wall at maximum head depth. Statistical analyses yielded significant main effects (p < 0.05) for both start type and swimmer experience. Starts executed by the more experienced swimmers were deeper and faster than those executed by the less experienced swimmers. When asked to dive shallowly, maximum head depth decreased (0.19 m) and head speed increased (0.33 ms-1) regardless of experience. The ability of all swimmers to modify start depth implies that spinal cord injuries during competitive swimming starts are not necessarily due to an inherent inability to control the depth of the start

Modify-and-Forward for Securing Cooperative Relay Communications

We proposed a new physical layer technique that can enhance the security of cooperative relay communications. The proposed approach modifies the decoded message at the relay according to the unique channel state between the relay and the destination such that the destination can utilize the modified message to its advantage while the eavesdropper cannot. We present a practical method for securely sharing the modification rule between the legitimate partners and present the secrecy outage probability in a quasi-static fading channel. It is demonstrated that the proposed scheme can provide a significant improvement over other schemes when the relay can successfully decode the source message.Comment: IEEE International Zurich Seminar on Communications, Feb. 201

FNAS modify matric and transparent experiments

Monotectic alloy materials are created by rapid melt/rapid solidification processing on the NASA KC-135. Separation of the uniform liquid into two liquids may occur by either of two processes; spinodal decomposition or nucleation followed by growth. In the first case, the liquid is unstable to composition waves, which form and grow, giving liquids of two different compositions. In the latter process discrete particles of the second liquid phase form via thermal fluctuations and then grow by diffusion. The two processes are very different, with the determining process being dictated by temperature, composition, and thermodynamic characteristics of the alloy. The first two quantities are process variables, while the third is determined by electronic interactions between the atoms in the alloy. In either case the initial alloy decomposition is followed by coarsening, resulting in growth of the particle size at nearly constant volume fraction. In particular, reduced gravity experiments on monotectic solutions have shown a number of interesting results in the KC-135. Monotectic solutions exhibit a miscibility gap in the liquid state, and consequently, gravity driven forces can dominate the solidification parameters at 1 g. In reduced gravity however, the distribution of the phases is different, resulting in new and interesting microstructures. The Rapid Melt/Rapid Quench Furnace allows one to melt a sample and resolidify it in one parabola of the KC-135's flight path, thus eliminating any accumulative influence of multiple parabolas to affect the microstructure of the material

Peran Guru Sekolah Minggu dalam Mengembangkan Talenta Anak Usia13-14 Tahun Melalui Tindakan Membangkitkan Semangat

Bakat anak sering kali terabaikan oleh orang tua dan guru. Hal ini dikarenakan kesibukan pekerjaan dan kurangnya perhatian terhadap pertumbuhan anak. Penelitian ini bertujuan untuk menemukan peran guru Sekolah Minggu dalam mengembangkan talenta melalui membangkitkan semangat. Usia objek penelitian adalah 13-14 tahun. Metode yang digunakan adalah kualitatif dengan teknik studi pustaka. Hasil penelitian menunjukkan bahwa membangkitkan semangat anak sekolah minggu dapat dilakukan dengan tiga cara. Pertama, peran guru sekolah minggu yang maksimal. Kedua, memahami psikologi anak usia 13-14 tahun. Ketiga, memfokuskan anak pada talenta yang dimiliki dengan melibatkan mereka dalam pelayanan di gereja. Manfaat dari penelitian ini adalah mengefektifkan anak-anak sekolah minggu dalam melayani di gereja dengan mengembangkan talenta. Talenta akan berfungsi secara efektif jika semangat anak Sekolah Minggu dibangkitkan dalam kegiatan sehari-hari.Bakat anak sering kali terabaikan oleh orang tua dan guru. Hal ini dikarenakan kesibukan pekerjaan dan kurangnya perhatian terhadap pertumbuhan anak. Penelitian ini bertujuan untuk menemukan peran guru Sekolah Minggu dalam mengembangkan talenta melalui membangkitkan semangat. Usia objek penelitian adalah 13-14 tahun. Metode yang digunakan adalah kualitatif dengan teknik studi pustaka. Hasil penelitian menunjukkan bahwa membangkitkan semangat anak sekolah minggu dapat dilakukan dengan tiga cara. Pertama, peran guru sekolah minggu yang maksimal. Kedua, memahami psikologi anak usia 13-14 tahun. Ketiga, memfokuskan anak pada talenta yang dimiliki dengan melibatkan mereka dalam pelayanan di gereja. Manfaat dari penelitian ini adalah mengefektifkan anak-anak sekolah minggu dalam melayani di gereja dengan mengembangkan talenta. Talenta akan berfungsi secara efektif jika semangat anak Sekolah Minggu dibangkitkan dalam kegiatan sehari-hari

MutLα heterodimers modify the molecular phenotype of Friedreich ataxia

This article has been made available through the Brunel Open Access Publishing Fund.Background: Friedreich ataxia (FRDA), the most common autosomal recessive ataxia disorder, is caused by a dynamic GAA repeat expansion mutation within intron 1 of FXN gene, resulting in down-regulation of frataxin expression. Studies of cell and mouse models have revealed a role for the mismatch repair (MMR) MutS-heterodimer complexes and the PMS2 component of the MutLα complex in the dynamics of intergenerational and somatic GAA repeat expansions: MSH2, MSH3 and MSH6 promote GAA repeat expansions, while PMS2 inhibits GAA repeat expansions. Methodology/Principal Findings: To determine the potential role of the other component of the MutLα complex, MLH1, in GAA repeat instability in FRDA, we have analyzed intergenerational and somatic GAA repeat expansions from FXN transgenic mice that have been crossed with Mlh1 deficient mice. We find that loss of Mlh1 activity reduces both intergenerational and somatic GAA repeat expansions. However, we also find that loss of either Mlh1 or Pms2 reduces FXN transcription, suggesting different mechanisms of action for Mlh1 and Pms2 on GAA repeat expansion dynamics and regulation of FXN transcription. Conclusions/Significance: Both MutLα components, PMS2 and MLH1, have now been shown to modify the molecular phenotype of FRDA. We propose that upregulation of MLH1 or PMS2 could be potential FRDA therapeutic approaches to increase FXN transcription. © 2014 Ezzatizadeh et al.This article has been made available through the Brunel Open Access Publishing Fund

How Should We Modify the High Energy Interaction Models ?

An analysis has been made of the present situation with respect to the high energy hadron-nucleus and nucleus-nucleus interaction models as applied to cosmic rays. As is already known, there are inconsistencies in the interpretation of experimental data on the primary mass composition, which appear when different EAS components are used for the analyses, even for the same experiment. In the absence of obvious experimental defects, there is a clear need for an improvement to the existing models; we argue that the most promising way is to enlist two effects which should be present in nucleus- nucleus collisions but have not been allowed for before. These are: a few percent energy transfer into the EAS electromagnetic component due to electron- positron pair production or electromagnetic radiation of the quark-gluon plasma and a small slow-down of the cascading process in its initial stages associated with the extended lifetime of excited nuclear fragments. The latter process displaces the shower maximum deeper into the atmosphere.Comment: 4 pages, 3 figures, talk presented at XII International Symposium on Very High Energy Cosmic Ray Interactions, CERN, Geneva, 15-19 July 2002, to be published in Nucl.Phys.B (Proc. Suppl.

How hole defects modify vortex dynamics in ferromagnetic nanodisks

Defects introduced in ferromagnetic nanodisks may deeply affect the structure and dynamics of stable vortex-like magnetization. Here, analytical techniques are used for studying, among other dynamical aspects, how a small cylindrical cavity modify the oscillatory modes of the vortex. For instance, we have realized that if the vortex is nucleated out from the hole its gyrotropic frequencies are shifted below. Modifications become even more pronounced when the vortex core is partially or completely captured by the hole. In these cases, the gyrovector can be partially or completely suppressed, so that the associated frequencies increase considerably, say, from some times to several powers. Possible relevance of our results for understanding other aspects of vortex dynamics in the presence of cavities and/or structural defects are also discussed.Comment: 9 pages, 4 page