Black limestone used in Lombard architecture

Black limestone samples from the quarries of Varenna (Lecco, I), Cene (Bergamo, I) and Riva di Solto (Bergamo, I) and widely used in Lombard architecture have been studied in terms of mineralogical, petrographic and chemical properties in order to provide a detailed characterisation and allow an unambiguous determination of their provenance. The inorganic and organic fractions have been separated from each other, and investigated using X-ray powder diffraction, atomic absorption, Hg-porosimetry, high performance liquid chromatography, gas chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopy. The occurrence of specific mineral phases, some binary chemical patterns (Fe/Mn, Zn/Sr, Zn/Co and Na/Cd) and the carbon chain relative molecular masses has proven to be useful markers to characterise unequivocally the materials studied.     

Three-dimensional kinematic analysis of the golf swing using instantaneous screw axis theory,part 1: methodology and verification

A number of recent studies have measured the extent and timing of segment rotation during the golf swing. A promising technique, instantaneous screw axis (ISA) theory, could provide a better expression of segment rotation. In Part 1 of this two-part study, the objectives are to identify the ISA of the pelvis, shoulders and left arm during the downswing, compute segment angular velocity relative to that segment’s ISA and verify that ISA theory is a valid tool to analyse segment rotation during the golf swing. Results indicate that for all subjects, at least 71% of marker velocity is a result of rotation about their respective ISA, when averaging results over the duration of the downswing, confirming that motion is primarily rotational. Furthermore, ISA position and orientation of each segment approaches, on average, the expected gross axis of rotation, confirming that motion about the ISA is representative of joint motion.     

Suppression of DC-link voltage unbalance in three-level neutral-point clamped converters

Two different control approaches for suppressing DC-link voltage unbalance in Three-Level Neutral-Point Clamped Converters (NPCs) are presented in this paper. They both guarantee DC-link voltage equalization over any NPC operating conditions, i.e. when the NPC feeds or is supplied by the main AC grid at different active and/or reactive power rates. The proposed control approaches consist of either a hysteresis or a proportional regulator, each of which synthesizes the most suitable control action based on the actual DC-link voltage unbalance. Particularly, two different PWM techniques have been developed in order to achieve DC-link voltage equalization successfully, preserving NPC voltage and current waveforms at the same time. The performances achievable by means of both the proposed control approaches have been compared to each other through an extensive simulation study in order to highlight their most important advantages and drawbacks, as well as their effectiveness over any operating conditions. Particularly, both control approaches are validated in the Matlab-Simulink environment referring to DC-link voltage equalization of an NPC that represents the point of common coupling between a DC microgrid and the main AC grid.     

A concurrent assessment of the positive and negative properties of a signaled shock schedule

A choice and a conditioned suppression procedure were used to assess concurrently the positive and negative properties of stimuli within a signaled shock schedule, Occasional shocks were presented to Ss responding on a variable-interval food schedule. Ss could choose whether shocks occurred alone or whether they were preceded by a 1-min signal. All Ss chose the signaled shock condition over the unsignaled one, even though food reinforced responding in the presence of the signal was suppressed. Rate of responding for food varied across stimulus conditions, with the lowest rate in the presence of the signal and the highest rate in its absence. An intermediate rate occurred under the unsignaled shock schedule. A safety analysis was applied to the data.     

TradeSmith: An Exercise to Demonstrate the Illusion of Control in Decision Making

Resource allocation decisions are a fundamental class of problems common throughout a business and therefore are found throughout business school curricula. Entrepreneurs must allocate capital, financiers must allocation cash, and production managers must create the best mix of multiple‐use resources. Within this context, a business school's curriculum, instructional materials, and learning processes must consider the implications of individual decision making. Our traditional instructional content and delivery methods may effectively teach how to set up a decision “problem” and how to obtain an optimal answer. Yet, we may not be teaching a key underlying factor: that entrepreneurs, managers, and future leaders appear to have implicit cognitive biases, which discount information and skew individual decision making. The results of this study demonstrate that a phenomenon known as the “illusion of control” presents a fundamental challenge to the efficacy of formalized educational programs on decision making. TradeSmith was designed as a problem‐based learning exercise to elicit for the illusion of control in a basic, resource allocation, decision environment. The subjects in this study demonstrate a decision‐making pattern consistent with the “illusion of control” phenomenon. Finally, by revealing individuals' implicit design‐making paradigms, TradeSmith helps them experience key issues for managerial decision making.     

Signal duration and choosing between signaled and unsignaled reward

The effects of signal duration when choosing between signaled and unsignaled response-independent reinforcers were examined in two experiments. In Experiment 1, albino rats were given a choice between signaled and unsignaled food delivered on variable-time 60-sec schedules using a 20-sec signal. All subjects preferred the signaled schedule at a level comparable to that reported in an earlier study using a 5-sec signal. Experiment 2 presented six rats with a direct choice between a 5-sec and a 20-sec signal condition, and three rats with a choice between a 1.5-sec and a 5-sec signal duration. Subjects preferred the 20-sec signal over the 5-sec signal, but no pReference was found with the 1.5-sec vs. a 5-sec signal. Current theoretical views, such as delay reduction and behavioral competition, are considered.     

Learner motivation for MOOC registration and the role of MOOCs as a university ‘taster’

Despite the widespread adoption of Massive Open Online Courses (MOOCs), no business model has emerged to make them sustainable from an institution standpoint. Using MOOCs as a marketing platform shows promise; but for this to succeed, it is necessary to understand the motivations of those who undertake them and to demonstrate how these same motivations can be better satisfied through enrolment in a fee-paying university course. We discuss the motivations for students as they progress through a MOOC and the factors that might lead to subsequent university enrolment. Our arguments are informed by MOOC statistics, the AIDA (attention, interest, desire, action) marketing model, and the literature on adult education, technology adoption, goal seeking and consumer value. We argue that most students are led to MOOC enrolment through close alignment of the course topic and subject matter with their personal goals and through the establishment of an attractive value proposition. Progress in the MOOC depends on whether this goal alignment is maintained, and whether the value assumptions of students are met or exceeded. We predict that subsequent university enrolment will most likely occur when the MOOC experience is both satisfying and representative of the university experience, and where the increased time and financial commitment demanded by formal study is offset by the greater likelihood of attaining the focal goal. For this strategy to succeed, it will be necessary for the host institution to actively work with MOOC students to create an awareness of appropriate fee-paying courses and to promote the benefits of university study. This has implications for the way institutions market their courses to MOOC students.     

Output-orientated Data Envelopment Analysis for measuring recycling efficiency: an application at Italian regional level

Pro-environmental behaviours associated with reducing, reusing and recycling have become increasingly matters of public policy concern. However, the existing literature on waste management rarely considers the cultural factors associated with predictors and enablers of recycling behaviours, nor has it deeply explored the relation between cultural access and such behaviours. Mindful of the relationship between cultural participation and learning, the main objective of this paper is to examine which Italian regions are ranked among the most ‘efficient’ in recycling, taking into account the variable of cultural participation. Using a Data Envelopment Analysis method applied to Italian regions for the period 2002–2007, we provide a measure of ‘efficiency’ that considers cultural consumptions (as input) and recycling (as output). Public data are drawn from two sources: the Italian Institute of Statistics database, ‘Cultura in cifre’, and the survey ‘Noi Italia – Environment section’. The results from the empirical analysis rank efficient and non-efficient regions in terms of connection between pro-environmental behaviour and cultural participation. The results also indicate a benchmark for ‘inefficient’ regions. The findings add to the discussion of cultural considerations for designing and implementing preventative pro-environmental strategies, that seek to reduce environmental costs and public environmental expenditure by factoring in – rather than out – the importance, role and impact of cultural access and participation.     

Classroom discussion and individual problem-solving in the teaching of history: Do different instructional approaches affect interest in different ways?

In this study, 100 Italian eighth graders were divided into two groups to compare the effects of two instructional interventions – the first based on problem-solving through discussion, the second on individual problem-solving – on students' learning of two historical topics (World War I and the economic boom), interest and self-perception of competence in history. The intervention based on discussion produced greater situational interest and understanding of the historical inquiry. The topic of World War I turned out to be an effective source of situational interest. Structural equation models showed that situational interest elicited by the use of discussion and by World War I impacted both on students' individual interest and on self-perception of competence in history.