Conductance quantization in etched Si/SiGe quantum point contacts

We fabricated strongly confined Schottky-gated quantum point contacts by etching Si/SiGe heterostructures and observed intriguing conductance quantization in units of approximately 1e2/h. Non-linear conductance measurements were performed depleting the quantum point contacts at fixed mode-energy separation. We report evidences of the formation of a half 1e2/h plateau, supporting the speculation that adiabatic transmission occurs through 1D modes with complete removal of valley and spin degeneracies.Comment: to appear in Physical Review

Geographies of Religion and Spirituality: Beyond the ‘officially’ sacred

The papers in this special issue, Geographies of Religion and Spirituality: Pilgrimage beyond the ‘Officially Sacred,’ are placed in the context of a comprehensive theoretical overview of the role that the sacred plays in shaping, conducting, controlling, and contesting pilgrimage. As scholarship examining the lived experiences of travelers has demonstrated, pilgrimages need not necessarily be religious in nature, nor be officially sanctioned. Rather, if pilgrimages are perceived as ‘hyper-meaningful’ by the practitioner, the authors in this special issue argue that a common denominator of all of these journeys is the perception of sacredness—a quality that is opposed to profane, everyday life. Separating the social category of ‘religion’ from the ‘sacred,’ these articles employ an interdisciplinary approach to theorize sacredness, its variability, and the ways in which it is officially recognized or condemned. Thus, the authors pay particular attention to the authorizing processes that religious and temporal power centers employ to either promote, co-opt, or stave off, such popular manifestations of devotion, focusing on three ways: through tradition, text or institutionalized norms. Referencing examples from across the globe, and linking them to the varied contributions in this special issue, this introduction complexifies the ways in which pilgrims, central authorities, locals and other stakeholders on the ground appropriate, negotiate, shape, contest, or circumvent the powerful forces of the sacred. Delving ‘beyond the officially sacred,’ this collective examination of pilgrimages, both well-established and new; religious and secular; authorized and not; the contributions to this special issue, as well as this Introduction, examines the interplay of a transcendent sacred for pilgrims and tourists so as to provide a blueprint for how work in the geography of religion and the fields of pilgrimage and religious tourism may move forward

Controlling the Cassie-to-Wenzel Transition: an Easy Route towards the Realization of Tridimensional Arrays of Biological Objects

In this paper we provide evidence that the Cassie-to-Wenzel transition, despite its detrimental effects on the wetting properties of superhydrophobic surfaces, can be exploited as an effective micro-fabrication strategy to obtain highly ordered arrays of biological objects. To this purpose we fabricated a patterned surface wetted in the Cassie state, where we deposited a droplet containing genomic DNA. We observed that, when the droplet wets the surface in the Cassie state, an array of DNA filaments pinned on the top edges between pillars is formed. Conversely, when the Cassie-to-Wenzel transition occurs, DNA can be pinned at different height between pillars. These results open the way to the realization of tridimensional arrays of biological objects

Gate-source distance scaling effects in H-terminated diamond MESFETs

In this paper, an analysis of gate-source and gate-drain scaling effects in MESFETs fabricated on hydrogen-terminated single-crystal diamond films is reported. The experimental results show that a decrease in gate-source spacing can improve the device performance by increasing the device output current density and its transconductance. On the contrary, the gate--drain distance produces less pronounced effects on device performance. Breakdown voltage, knee voltage, and threshold voltage variations due to changes in gate-source and drain-source distances have also been investigated. The obtained results can be used as a design guideline for the layout optimization of H-terminated diamond-based MESFETs

Reframing and Reconceptualising Gambling tourism in Macau as a Chinese Pilgrimage

While dominant discourses, media representations and corporate entities in China downplay the presence of Chinese mainland gambling in Macau, Beijing sanctions millions of its citizens to make the journey to Macau to gamble each year. While Macau’s success is often put down to the extent to which visitors are drawn to a secular destination with integrated resorts to engage in individualistic activities, our approach explores Chinese gambling tourists’ movements, rituals and behaviours along post-structuralist lines, so as to generate new insights. The analysis shows how the metaphor of pilgrimage is an important lens to address individual and communal practices amongst outbound Chinese gambling tourists and brings to light the hyper-meaningfulness, shared values, ritualization, play, risk, and liminal conditions that characterise the processes of their entanglements and the centrality of commercial and political interests. In particular, the analysis indicates the need to explore the significance of cultural, spiritual, economic and social dimensions of Chinese outbound tourism, as well as the unique discourses of power and control affecting their movement and practices. By reframing and reconceptualising gambling tourists as a Chinese pilgrimage, we account for manifestations of culture, governmentality and intentional ritualization as well as contribute an alternative construction of pilgrimage beyond euro-centric accounts, which in turn, will stimulate discussion on geographies of pilgrimage

Clinical utility of dual energy computed tomography in gout: Current concepts and applications

Summary. Gout is the most common inflammatory arthritis and is increasing in prevalence and incidence in many countries worldwide. Dual Energy Computed Tomography (DECT) has a high diagnostic accuracy in established gout, but its diagnostic sensitivity is low in subjects with recent-onset gout. A meta-analysis of 17 studies showed a pooled sensitivity and specificity of 0.85 and 0.88, respectively. DECT is a useful diagnostic tool for patients with contraindications for joint aspiration or for those who refuse joint aspiration. This article aims to give an up to date review and summary of existing literature on the role and accuracy of DECT in the imaging of gout. (www.actabiomedica.it)

imaging the coupling of terahertz radiation to a high electron mobility transistor in the near field

We used AlGaN/GaN high electron mobility transistors as room-temperature direct detectors of radiation at 0.15 THz from a free electron laser, hence 5 times higher than their cutoff frequency of 30 GHz. By near-field active mapping we investigated the antenna-like coupling of the radiation to the transistor channel. We formulate a model for the detection based on self-mixing in the transistor channel. The noise equivalent power is found in the range of 10^{-7} W/Hz^{0.5} without any optimization of the device responsivity. Present day AlGaN/GaN fabrication technology may provide operation at higher frequency, integration of amplifiers for improved responsivity and fast switches for multiplexing, which make the detector here described the basic element of a monolithic terahertz focal plane array

Accurate large-signal equivalent circuit of surface channel diamond FETs based on the Chalmers model

The paper presents a large-signal nonlinear circuit-oriented model for polycrystalline and single-crystal H-terminated diamond MESFETs implemented within the Agilent ADS design suite. The DC characteristics of such devices suggest that the channel free charge control law may be modeled using the same strategy adopted for III-V HEMTs. For this reason, the well-known nonlinear Chalmers (Angelov) circuit model was chosen as the starting point for the development of the present non-linear diamond MESFET model. Model fitting was performed against DC and multibias small signal measurements, with good agreement. Model validations versus large-signal (power) measurements point out the accuracy of the proposed approach to simulate the behavior of H-terminated diamond MESFETs under large-signal operatio