Large NN reduction with the Twisted Eguchi-Kawai model

We examine the breaking of $Z_N$ symmetry recently reported for the Twisted Eguchi-Kawai model (TEK). We analyse the origin of this behaviour and propose simple modifications of twist and lattice action that could avoid the problem. Our results show no sign of symmetry breaking and allow us to obtain values of the large $N$ infinite volume string tension in agreement with extrapolations from results based upon straightforward methods.Comment: latex file 14 pages, 4 figure

Optimum selection of variable pitch for chatter suppression in face milling operations

Cutting capacity can be seriously limited in heavy duty face milling processes due to self-excited structural vibrations. Special geometry tools and, specifically, variable pitch milling tools have been extensively used in aeronautic applications with the purpose of removing these detrimental chatter vibrations, where high frequency chatter related to slender tools or thin walls limits productivity. However, the application of this technique in heavy duty face milling operations has not been thoroughly explored. In this paper, a method for the definition of the optimum angles between inserts is presented, based on the optimum pitch angle and the stabilizability diagrams. These diagrams are obtained through the brute force (BF) iterative method, which basically consists of an iterative maximization of the stability by using the semidiscretization method. From the observed results, hints for the selection of the optimum pitch pattern and the optimum values of the angles between inserts are presented. A practical application is implemented and the cutting performance when using an optimized variable pitch tool is assessed. It is concluded that with an optimum selection of the pitch, the material removal rate can be improved up to three times. Finally, the existence of two more different stability lobe families related to the saddle-node and flip type stability losses is demonstrated

Soft skills and dental education

Soft skills and hard skills are essential in the practice of dentistry. While hard skills deal with technical proficiency, soft skills relate to a personal values and interpersonal skills that determine a person's ability to fit in a particular situation. These skills contribute to the success of organisations that deal face-to-face with clients. Effective soft skills benefit the dental practice. However, the teaching of soft skills remains a challenge to dental schools. This paper discusses the different soft skills, how they are taught and assessed and the issues that need to be addressed in their teaching and assessment. The use of the module by the Faculty of Dentistry, University of Malaya for development of soft skills for institutions of higher learning introduced by the Ministry of Higher Education, Malaysia.Article Link: http://onlinelibrary.wiley.com/doi/10.1111/eje.12017/abstrac

Contributions towards sustainable cities: urban monitoring and designing tools

The 21st century is the century of cities and urbanization [1]. We live in an increasingly urbanized world where it is projected that by 2050 over 70% of our population will live in cities. The city of the twenty-first century faces major challenges, including social and economic, excessive or even wasteful consumption of resources, transportation congestion, and environmental degradation. In order to address to these critical challenges, an urban renaissance should be founded on principles of sustainable design, economic strength, environmental responsibility, good governance and social well-being [2]. In the current and future research, three elements will be investigated: (i) understanding the consumption and functioning of cities through multi-scalar monitoring systems (ii) improving the air quality and reducing the carbon footprint of cities (iii) and the design of optimal green transportation systems

The response of a neutral atom to a strong laser field probed by transient absorption near the ionisation threshold

We present transient absorption spectra of an extreme ultraviolet attosecond pulse train in helium dressed by an 800 nm laser field with intensity ranging from $2times10^{12}$ W/cm$^2$ to $2times10^{14}$ W/cm$^2$. The energy range probed spans 16-42 eV, straddling the first ionisation energy of helium (24.59 eV). By changing the relative polarisation of the dressing field with respect to the attosecond pulse train polarisation we observe a large change in the modulation of the absorption reflecting the vectorial response to the dressing field. With parallel polarized dressing and probing fields, we observe significant modulations with periods of one half and one quarter of the dressing field period. With perpendicularly polarized dressing and probing fields, the modulations of the harmonics above the ionisation threshold are significantly suppressed. A full-dimensionality solution of the single-atom time-dependent Schr odinger equation obtained using the recently developed ab-initio time-dependent B-spline ADC method reproduce some of our observations

Resonant Enhancement of Charge Density Wave Diffraction in the Rare-Earth Tritellurides

We performed resonant soft X-ray diffraction on known charge density wave (CDW) compounds, rare earth tri-tellurides. Near the $M_5$ (3d - 4f) absorption edge of rare earth ions, an intense diffraction peak is detected at a wavevector identical to that of CDW state hosted on Te$_2$ planes, indicating a CDW-induced modulation on the rare earth ions. Surprisingly, the temperature dependence of the diffraction peak intensity demonstrates an exponential increase at low temperatures, vastly different than that of the CDW order parameter. Assuming 4f multiplet splitting due to the CDW states,we present a model to calculate X-ray absorption spectrum and resonant profile of the diffraction peak, agreeing well with experimental observations. Our results demonstrate a situation where the temperature dependence of resonant X-ray diffraction peak intensity is not directly related to the intrinsic behavior of the order parameter associated with the electronic order, but is dominated by the thermal occupancy of the valence states.Comment: 7 pages, 5 figure

Coerced Hospital Admission and Symptom Change-A Prospective Observational Multi-Centre Study

PMCID: PMC3227658 Freely available online via CCplosone.org

Hawking Radiation of Dirac Particles in a Variable-mass Kerr Space-time

Hawking effect of Dirac particles in a variable-mass Kerr space-time is investigated by using a method called as the generalized tortoise coordinate transformation. The location and the temperature of the event horizon of the non-stationary Kerr black hole are derived. It is shown that the temperature and the shape of the event horizon depend not only on the time but also on the angle. However, the Fermi-Dirac spectrum displays a residual term which is absent from that of Bose-Einstein distribution.Comment: 12 pages in 12pt Revtex, no figure, to appear in Gen. Rel. Grav. Vol.33, No.7 (2001