Measurements of Solid Spheres Bouncing Off Flat Plates

Recent years have seen a substantial increase of interest in the flows of granular materials whose rheology is dominated by the physical contact between particles and between particles and the containing walls. Considerable advances in the theoretical understanding of rapid granular material flows have been made by the application of the statistical methods of molecular gas dynamics (e.g., Jenkins and Savage (1983), Lun et al. (1984)) and by the use of computers simulations of these flows (e.g., Campbell and Brennen (1985), Walton (1984)). Experimental studies aimed at measurements of the fundamental rheology properties are much less numerous and are understandably limited by the great difficulties involved in trying to measure velocity profiles, solid fraction profiles, and fluctuating velocities within a flowing granular material. Nevertheless, it has become clear that one of the most severe problems encountered when trying to compare experimental data with the theoretical models is the uncertainty in the material properties governing particle/particle or particle/wall collisions. Many of the theoretical models and computer simulations assume a constant coefficient of restitution (and, in some cases, a coefficient of friction). The purpose of the present project was to provide some documentation for particle/wall collisions by means of a set of relatively simple experiments in which solid spheres of various diameters and materials were bounced off plates of various thickness and material. The objective was to provide the kind of information on individual particle/wall collisions needed for the theoretical rheological models and computer simulations of granular material flows: in particular, to help resolve some of the issues associated with the boundary condition at a solid wall. For discussion of the complex issues associated with dynamic elastic or inelastic impact, reference is made to Goldsmith (1960) and the recent text by Johnson (1985)

Counting function for a sphere of anisotropic quartz

We calculate the leading Weyl term of the counting function for a mono-crystalline quartz sphere. In contrast to other studies of counting functions, the anisotropy of quartz is a crucial element in our investigation. Hence, we do not obtain a simple analytical form, but we carry out a numerical evaluation. To this end we employ the Radon transform representation of the Green's function. We compare our result to a previously measured unique data set of several tens of thousands of resonances.Comment: 16 pages, 11 figure

The impact of two-dimensional elastic disk

The impact of a two-dimensional elastic disk with a wall is numerically studied. It is clarified that the coefficient of restitution (COR) decreases with the impact velocity. The result is not consistent with the recent quasi-static theory of inelastic collisions even for very slow impact. The abrupt drop of COR is found due to the plastic deformation of the disk, which is assisted by the initial internal motion.(to be published in J. Phys. Soc. Jpn.)Comment: 6 Pages,2 figure

An optimally concentrated Gabor transform for localized time-frequency components

Gabor analysis is one of the most common instances of time-frequency signal analysis. Choosing a suitable window for the Gabor transform of a signal is often a challenge for practical applications, in particular in audio signal processing. Many time-frequency (TF) patterns of different shapes may be present in a signal and they can not all be sparsely represented in the same spectrogram. We propose several algorithms, which provide optimal windows for a user-selected TF pattern with respect to different concentration criteria. We base our optimization algorithm on $l^p$-norms as measure of TF spreading. For a given number of sampling points in the TF plane we also propose optimal lattices to be used with the obtained windows. We illustrate the potentiality of the method on selected numerical examples

India: Urban Finance and Governance Review - Volume I Executive Summary and Main Report

The report makes an in depth analysis of what to expect of future urban population growth in cities across India. Cities play a critical role in India\u27s development. While its one billion-plus population is predominantly rural, over 300 million people live in urban areas. One-third of this population lives in 35 urban agglomerations or cities exceeding one million. Cities\u27 governments are responsible for delivering various public services, yet severe infrastructures shortages in water supply and sanitation, roads, transportation, housing and waste management, and inefficient management have resulted in poor quality services. These inadequate services and worsening environmental conditions affect the poor. Between 1950 and 2000 India\u27s urban population increased from 62 to 288 million. Already strained to provide services and quality of life to existing urban residents, cities will face tremendous challenges in expanding existing infrastructure and avoiding deterioration of living standards due to congestion, pollution, and lack of basic services. A doubling of the population over 30 years means that by 2030 there will be a second Mumbai, a second Calcutta, and a second Bangalore that must be fed, supplied with water, sanitation, electricity, give public and private transportation options; and where garbage must be disposed of. The report concludes by laying out a series of state and local actions over the short-medium and long-term to enhance fiscal sustainability and strengthening institutional capacity building of state and local governments

India: Urban Finance and Governance Review Volume II: Case Study Annexes

The report makes an in depth analysis of what to expect of future urban population growth in cities across India. Cities play a critical role in India\u27s development. While its one billion-plus population is predominantly rural, over 300 million people live in urban areas. One-third of this population lives in 35 urban agglomerations or cities exceeding one million. Cities\u27 governments are responsible for delivering various public services, yet severe infrastructures shortages in water supply and sanitation, roads, transportation, housing and waste management, and inefficient management have resulted in poor quality services. These inadequate services and worsening environmental conditions affect the poor. Between 1950 and 2000 India\u27s urban population increased from 62 to 288 million. Already strained to provide services and quality of life to existing urban residents, cities will face tremendous challenges in expanding existing infrastructure and avoiding deterioration of living standards due to congestion, pollution, and lack of basic services. A doubling of the population over 30 years means that by 2030 there will be a second Mumbai, a second Calcutta, and a second Bangalore that must be fed, supplied with water, sanitation, electricity, give public and private transportation options; and where garbage must be disposed of. The report concludes by laying out a series of state and local actions over the short-medium and long-term to enhance fiscal sustainability and strengthening institutional capacity building of state and local governments

A model for inter-module analysis and optimizing compilation

Recent research into the implementation of logic programming languages has demonstrated that global program analysis can be used to speed up execution by an order of magnitude. However, currently such global program analysis requires the program to be analysed as a whole: sepárate compilation of modules is not supported. We describe and empirically evalúate a simple model for extending global program analysis to support sepárate compilation of modules. Importantly, our model supports context-sensitive program analysis and multi-variant specialization of procedures in the modules

Introducing Extended Consultations for Patients with Severe Mental Illness in General Practice.:Results from the SOFIA Feasibility Study

Abstract Background People with a severe mental illness (SMI) have shorter life expectancy and poorer quality of life compared to the general population. Most years lost are due to cardiovascular disease, respiratory disease, and various types of cancer. We co-designed an intervention to mitigate this health problem with key stakeholders in the area, which centred on an extended consultations for people with SMI in general practice. This study aimed to1) investigate general practitioners’ (GPs) experience of the feasibility of introducing extended consultations for patients with SMI, 2) assess the clinical content of extended consultations and how these were experienced by patients, and 3) investigate the feasibility of identification, eligibility screening, and recruitment of patients with SMI. Methods The study was a one-armed feasibility study. We planned that seven general practices in northern Denmark would introduce extended consultations with their patients with SMI for 6 months. Patients with SMI were identified using practice medical records and screened for eligibility by the patients’ GP. Data were collected using case report forms filled out by practice personnel and via qualitative methods, including observations of consultations, individual semi-structured interviews, a focus group with GPs, and informal conversations with patients and general practice staff. Results Five general practices employing seven GPs participated in the study, which was terminated 3 ½ month ahead of schedule due to the COVID-19 pandemic. General practices attempted to contact 57 patients with SMI. Of these, 38 patients (67%) attended an extended consultation, which led to changes in the somatic health care plan for 82% of patients. Conduct of the extended consultations varied between GPs and diverged from the intended conduct. Nonetheless, GPs found the extended consultations feasible and, in most cases, beneficial for the patient group. In interviews, most patients recounted the extended consultation as beneficial. Discussion Our findings suggest that it is feasible to introduce extended consultations for patients with SMI in general practice, which were also found to be well-suited for eliciting patients’ values and preferences. Larger studies with a longer follow-up period could help to assess the long-term effects and the best implementation strategies of these consultations

Simulation for the oblique impact of a lattice system

The oblique collision between an elastic disk and an elastic wall is numerically studied. We investigate the dependency of the tangential coefficient of restitution on the incident angle of impact. From the results of simulation, our model reproduces experimental results and can be explained by a phenomenological theory of the oblique impact.Comment: 30 pages, 9 figures, submitted to J. Phys. Soc. Japa