Quantum-Mechanically Induced Asymmetry in the Phase Diagrams of Spin-Glass Systems

The spin-1/2 quantum Heisenberg model is studied in all spatial dimensions d by renormalization-group theory. Strongly asymmetric phase diagrams in temperature and antiferromagnetic bond probability p are obtained in dimensions d \geq 3. The asymmetry at high temperatures approaching the pure ferromagnetic and antiferromagnetic systems disappears as d is increased. However, the asymmetry at low but finite temperatures remains in all dimensions, with the antiferromagnetic phase receding to the ferromagnetic phase. A finite-temperature second-order phase boundary directly between the ferromagnetic and antiferromagnetic phases occurs in d \geq 6, resulting in a new multicritical point at its meeting with the boundaries to the paramagnetic phase. In d=3,4,5, a paramagnetic phase reaching zero temperature intervenes asymmetrically between the ferromagnetic and reentrant antiferromagnetic phases. There is no spin-glass phase in any dimension.Comment: Added discussion of second-order transitions between ordered phases, driven by quenched disorder. 4 pages, 1 figure, 3 tables. Published versio

Infinitely Robust Order and Local Order-Parameter Tulips in Apollonian Networks with Quenched Disorder

For a variety of quenched random spin systems on an Apollonian network, including ferromagnetic and antiferromagnetic bond percolation and the Ising spin glass, we find the persistence of ordered phases up to infinite temperature over the entire range of disorder. We develop a renormalization-group technique that yields highly detailed information, including the exact distributions of local magnetizations and local spin-glass order parameters, which turn out to exhibit, as function of temperature, complex and distinctive tulip patterns.Comment: 5 pages, 4 figures; updated to reflect minor changes in published versio

Frustrated Further-Neighbor Antiferromagnetic and Electron-Hopping Interactions in the d=3 tJ Model: Finite-Temperature Global Phase Diagrams from Renormalization-Group Theory

The renormalization-group theory of the d=3 tJ model is extended to further-neighbor antiferromagnetic or electron-hopping interactions, including the ranges of frustration. The global phase diagram of each model is calculated for the entire ranges of temperatures, electron densities, and further/first-neighbor interaction strength ratios. In addition to the \tau_{tJ} phase seen in earlier studies of the nearest-neighbor d=3 tJ model, the \tau_{Hb} phase seen before in the d=3 Hubbard model appears both near and away from half-filling. These distinct \tau phases potentially correspond to different (BEC-like and BCS-like) superconducting phases.Comment: Improved figures, added discussions, added references. Published version. 12 pages, 5 figures, 6 table

A Distributed Economics-based Infrastructure for Utility Computing

Existing attempts at utility computing revolve around two approaches. The first consists of proprietary solutions involving renting time on dedicated utility computing machines. The second requires the use of heavy, monolithic applications that are difficult to deploy, maintain, and use. We propose a distributed, community-oriented approach to utility computing. Our approach provides an infrastructure built on Web Services in which modular components are combined to create a seemingly simple, yet powerful system. The community-oriented nature generates an economic environment which results in fair transactions between consumers and providers of computing cycles while simultaneously encouraging improvements in the infrastructure of the computational grid itself.Comment: 8 pages, 1 figur

Infinitely Robust Order and Local Order-Parameter Tulips in Apollonian Networks with Quenched Disorder

For a variety of quenched random spin systems on an Apollonian network, including ferromagnetic and antiferromagnetic bond percolation and the Ising spin glass, we find the persistence of ordered phases up to infinite temperature over the entire range of disorder. We develop a renormalization-group technique that yields highly detailed information, including the exact distributions of local magnetizations and local spin-glass order parameters, which turn out to exhibit, as function of temperature, complex and distinctive tulip patterns

D-Day for Decision-Makers: Considerations for a New Public School Financing System in California

Sixteen years have passed since the United States Supreme Court concluded, in Brown v. Board of Education, that the fourteenth amendment required equality in education for all. Although that historical decision confined itself to abolishing segregation in the public schools, teh fourteenth amendment does not so confine itself. Equality is not the province of the blacks. Equality must be practiced wherever inequality looms large, regardless of race, creed, or cause. In August, 1971, the Supreme Court of California found that unequal wealth distribution in California has resulted in unequal education in the public schools. The court in Serrano v. Priest held that the California public school financing system violates the equal protection clause of the fourteenth amendment. This system ...invidiously discriminates against the poor because it makes the quality of a child\u27s education a function of the wealth of his parents and neighbors

Movement disorders care in pakistan

Earlier discussions about a professional society relating to movement disorders took place about a decade ago and were felt to be a little premature. However PSN nominated Dr Nadir Ali Syed to promote movement disorders related activities. Dr Nadir worked with patients to form a patient centered body, the Pakistan Parkinson\u27s Society which has been quite active in the last several years

A Review of Emergent Masculinities: Gendered Power and Social Change in the Biafran Atlantic Age. By Ndubueze L. Mbah. Athens: Ohio University Press, 2019. 307 p. $ 33.20.

For a long period of time, women played significant roles in many pre-colonial African societies, serving in various capacities as religious, political, and economic leaders. The exact roles and status of these women, however, differ contrastively from one society to another based on factors such as religion, culture, and social organization. Though this unpopular fact about African history receives little or no attention from scholars, few studies offer some insights into the history and transformation of the powers of female leaders in Africa (Weir, 2000; Ogbomo, 2005; Weir, 2006; Achebe, 2011; Akyeampong & Fofack, 2014). Along this intersection, Mba\u27s Emergent Masculinities is no doubt a significant contribution, especially to the pre-colonial and colonial history of the Igbo at the Bight of Biafra (1750-1920), focusing mainly on how certain Western influences such as the Trans-Atlantic Slavery, legitimate trade, and colonialism shaped the peoples\u27 socio-political and economic institutions

An Art-Historical Analysis of Selected Sacred Sufi Paintings in Kano, Nigeria

‘Iconoclasm’, which may simply be defined as the destruction of artworks as a result of hatred towards them is a common phenomenon in all the three major Abrahamic desert religions; Judaism, Christianity and Islam. Because Islam frowns at representational art, especially sculptures in the round, many Muslim artists pursue and develop their creativity in the elegant Arabic calligraphic embellishments used to adorn the walls of mosques, palaces and the covers of Islamic books. However, despite the growing nature of iconoclasm amongst mainstream Muslims, the Sufis see no harm in visually and artistically representing their saints and hermits as a way to honour them and seek their barakah (blessings). It is on this basis that this paper examines selected sacred Sufi paintings of Kano, Nigeria. Relying heavily on oral interviews and written sources this paper traces the historical development of sacred Sufi paintings in Kano, Nigeria, focusing largely on the art historical appreciation and contextualization of such paintings. The paper also found out that despite the importance of sacred Sufi paintings in the reconstruction of history, they receive little or no scholarly attention. &nbsp