Colour Confinement and Deformed Baryons in Quantum Chromodynamics

The confinement of coloured entities in Quantum Chromodynamics (QCD) is traced to colour singletness of the observed entities. This is believed to arise from colour singlet state of quark-antiquark for mesons and a fully colour antisymmetric state for baryons. This demands a spherically symmetric baryon in the ground state. However it is pointed out that a deformed baryon in the ground state has been found to be extremely successful phenomenology. There are convincing experimental supports for a deformed nucleon as well. This means that something has been missed in the fundamental theory. In this paper this problem is traced to a new colour singlet state for baryons which has been missed hitherto and incorporation of which provides a consistent justification of a deformed baryon in the ground state. Interestingly this new colour singlet state is global in nature.Comment: 5 pages, 1 figur

Shearfree Condition and dynamical Instability in f(R,T)f(R,T) gravity

The implications of shearfree condition on instability range of anisotropic fluid in $f(R,T)$ are studied in this manuscript. A viable $f(R, T)$ model is chosen to arrive at stability criterion, where $R$ is Ricci scalar and $T$ is the trace of energy momentum tensor. The evolution of spherical star is explored by employing perturbation scheme on modified field equations and contracted Bianchi identities in $f(R, T)$. The effect of imposed shearfree condition on collapse equation and adiabatic index $\Gamma$ is studied in Newtonian and post-Newtonian regimes.Comment: 16 page

Sociological Knowledge and Transformation at ‘Diversity University’, UK

This chapter is based on a case study of one UK university sociology department and shows how sociology knowledge can transform the lives of ‘non-traditional’ students. The research from which the case is drawn focused on four departments teaching sociology-related subjects in universities positioned differently in UK league tables. It explored the question of the relationship between university reputation, pedagogic quality and curriculum knowledge, challenging taken-for-granted judgements about ‘quality’ and in conceptualising ‘just’ university pedagogy by taking Basil Bernstein’s ideas about how ‘powerful’ knowledge is distributed in society to illuminate pedagogy and curriculum. The project took the view that ‘power’ lies in the acquisition of specific (inter)disciplinary knowledges which allows the formation of disciplinary identities by way of developing the means to think about and act in the world in specific ways. We chose to focus on sociology because (1) university sociology is taken up by all socio-economic classes in the UK and is increasingly taught in courses in which the discipline is applied to practice; (2) it is a discipline that historically pursues social and moral ambition which assists exploration of the contribution of pedagogic quality to individuals and society beyond economic goals; (3) the researchers teach and research sociology or sociology of education - an understanding of the subjects under discussion is essential to make judgements about quality. ‘Diversity’ was one of four case study universities. It ranks low in university league tables; is located in a large, multi-cultural English inner city; and, its students are likely to come from lower socio-economic and/or ethnic minority groups, as well as being the first in their families to attend university. To make a case for transformative teaching at Diversity, the chapter draws on longitudinal interviews with students, interviews with tutors, curriculum documents, recordings of teaching, examples of student work, and a survey. It establishes what we can learn from the case of sociology at Diversity, arguing that equality, quality and transformation for individuals and society are served by a university curriculum which is research led and challenging combined with pedagogical practices which give access to difficult-to-acquire and powerful knowledge

Computation of supersonic jet mixing noise for an axisymmetric CD nozzle using k-epsilon turbulence model

The turbulent mixing noise of a supersonic jet is calculated for a round convergent-divergent nozzle at the design pressure ratio. Aerodynamic computations are performed using the PARC code with a k-epsilon turbulence model. Lighthill's acoustic analogy combined with Ribner's assumption is adopted. The acoustics solution is based upon the methodology followed by GE in the MGB code. The source correlation function is expressed as a linear combination of second-order tensors. Assuming separable second-order correlations and incorporating Batchelor's isotropic turbulence model, the source term was calculated from the kinetic energy of turbulence. A Gaussian distribution for the time-delay of correlation was introduced. The computational fluid dynamics (CFD) solution was used to obtain the source strength as well as the characteristic time-delay of correlation. The effect of sound/flow interaction was incorporated using the high frequency asymptotic solution to Lilley's equation for axisymmetric geometries. Acoustic results include sound pressure level directivity and spectra at different polar angles. The aerodynamic and acoustic results demonstrate favorable agreement with experimental data

A survey of the broadband shock associated noise prediction methods

Several different prediction methods to estimate the broadband shock associated noise of a supersonic jet are introduced and compared with experimental data at various test conditions. The nozzle geometries considered for comparison include a convergent and a convergent-divergent nozzle, both axisymmetric. Capabilities and limitations of prediction methods in incorporating the two nozzle geometries, flight effect, and temperature effect are discussed. Predicted noise field shows the best agreement for a convergent nozzle geometry under static conditions. Predicted results for nozzles in flight show larger discrepancies from data and more dependable flight data are required for further comparison. Qualitative effects of jet temperature, as observed in experiment, are reproduced in predicted results

Analysis and Evaluation of Different Compensation Techniques for Fiber Losses

تعتبر التأثيرات الخطية وغير الخطية في الألياف الضوئية من العوامل المهمة جدًا والمؤثرة التي تؤثر على قوة الإشارة المنقولة داخل الألياف الضوئية. في هذا البحث تم عرض النموذج الرياضي لهذه التأثيرات. كما تم استعراض أهم الطرق المستخدمة لتعويض هذه الخسائر. تتضمن طرق التعويض التي تمت مراجعتها تأثيرات خطية وغير خطية متنوعة ، حيث ركزت معظم الطرق التي تمت مراجعتها على زيادة طول الألياف الضوئية لنقل الإشارة بأقل طاقة مستهلكة ومعدل نقل بيانات مرتفع بتكلفة تصميم منخفضة.The Linear and nonlinear effects in optical fibers are very important and influential factors that effect on the power of the signal transmitted within the optical fiber. In this paper, the mathematical model for these effects was presented. The most important methods used to compensate these losses were also reviewed. The compensation methods reviewed include various linear and nonlinear effects most of the methods reviewed focused on increasing the length of the optical fiber to transmit the signal with the least consumed power and high data transfer rate at low design cos

M-ATTEMPT: A New Energy-Efficient Routing Protocol for Wireless Body Area Sensor Networks

In this paper, we propose a new routing protocol for heterogeneous Wireless Body Area Sensor Networks (WBASNs); Mobility-supporting Adaptive Threshold-based Thermal-aware Energy-efficientMulti-hop ProTocol (M-ATTEMPT). A prototype is defined for employing heterogeneous sensors on human body. Direct communication is used for real-time traffic (critical data) or on-demand data while Multi-hop communication is used for normal data delivery. One of the prime challenges in WBASNs is sensing of the heat generated by the implanted sensor nodes. The proposed routing algorithm is thermal-aware which senses the link Hot-spot and routes the data away from these links. Continuous mobility of human body causes disconnection between previous established links. So, mobility support and energy-management is introduced to overcome the problem. Linear Programming (LP) model for maximum information extraction and minimum energy consumption is presented in this study. MATLAB simulations of proposed routing algorithm are performed for lifetime and successful packet delivery in comparison with Multi-hop communication. The results show that the proposed routing algorithm has less energy consumption and more reliable as compared to Multi-hop communication.Comment: arXiv admin note: substantial text overlap with arXiv:1208.609