On the Deflexion of Anisotropic Structural Composite Aerodynamic Components

This paper presents closed form solutions to the classical beam elasticity differential equation in order to effectively model the displacement of standard aerodynamic geometries used throughout a number of industries. The models assume that the components are constructed from in-plane generally anisotropic (though shown to be quasi-isotropic) composite materials. Exact solutions for the displacement and strains for elliptical and FX66-S-196 and NACA 63-621 aerofoil approximations thin wall composite material shell structures, with and without a stiffening rib (shear-web), are presented for the first time. Each of the models developed is rigorously validated via numerical (Runge-Kutta) solutions of an identical differential equation used to derive the analytical models presented. The resulting calculated displacement and material strain fields are shown to be in excellent agreement with simulations using the ANSYS and CATIA commercial finite element (FE) codes as well as experimental data evident in the literature. One major implication of the theoretical treatment is that these solutions can now be used in design codes to limit the required displacement and strains in similar components used in the aerospace and most notably renewable energy sector

Preface: The Legal and Ethical Environment of Business

In writing The Legal and Ethical Environment of Business, Terence Lau and Lisa Johnson had simple aims: To present the often overwhelming legal environment of business in an exciting and relevant way To provide faculty a way of achieving that goal WHAT\u27S NEW IN 2.0: RELEVANT CASES & EXAMPLES With updated information in each chapter, this textbook will continue to illustrate the relevance of law and ethics to the happenings of the present day. NEW AREAS OF COVERAGE: Agency law, ethics, bankruptcy, consumer protection, debtor-creditor relations, and secured transactions. Some of this material may be contained in one or two new chapters, and some of this material may be added as a new section or sections in an existing chapter. This record contains the book\u27s prefac

The Biological Data Sustainability Paradox

Biological data in digital form has become a, if not the, driving force behind innovations in biology, medicine, and the environment. No study and no model would be complete without access to digital data (including text) collected by others and available in public repositories. With this ascent in the fundamental importance of data for reproducible scientific progress has come a troubling paradox.Comment: 12 pages 5852 words 1 figur

Scent chemistry and patterns of thermogenesis in male and female cones of the African cycad Encephalartos natalensis (Zamiaceae)

Most, if not all, extant cycads are pollinated by insects which use the cones as larval brood sites. These interactions appear to be mediated by cone volatiles, and, in some species, by patterns of thermogenesis. We investigated the chemical composition of volatile emissions and patterns of thermogenesis in cones of the South African cycad Encephalartos natalensis, using a gas chromatograph–mass spectrometer (GC–MS) and miniature temperature data loggers (ibuttons), respectively. This was done during various developmental stages (before and during receptivity and pollen release) for both female and male cones. A total of 31 compounds were identified in headspace samples; 17 of which were common to both sexes, 12 found only in male cones, and two found only in female cones. The major volatiles in pollen and female cones are (3E)-1,3-octadiene (averaging 54.25% and 15.82% of total emissions), (3E,5Z)-1,3,5-octatriene (averaging 13.37% and 47.66%), and α-pinene (averaging 16.29% and 12.24%). Female cones were not thermogenic before and during receptivity whereas pollen cones were thermogenic during pollen shedding. Thermogenesis of male cones occurred between 1400 h and 1530 h on successive afternoons, reaching an average of c. 10.5 °C above ambient temperature. Volatile emissions and thermogenesis occurred in association with insect activity on the cones suggesting that they both play a role in regulating insect behaviour

Cash Transfers as a Response to COVID-19: A Randomized Experiment in Kenya

We deliver an unconditional cash transfer equal to one month’s average profit to a randomly selected group of Kenyan female microenterprise owners in May 2020 at the outset of exponential growth in COVID-19 cases. Firm profit, inventory spending, and food expenditures increased relative to a control group. Entrepreneurs recovered about one third of the profit lost during the crisis. The transfers caused greater business activity by inducing previously closed businesses to re-open. PPE spending and precautionary management practices increase to mitigate this effect, but only among those who perceive major health risk from COVID-19. The results suggest cash transfers promoted economic stabilization during the crisis, but may work against the public health goal of reducing interpersonal interaction

Ice Dynamics Preceding Catastrophic Disintegration of the Floating Part of Jakobshavn Isbræ, Greenland

The floating terminal of Jakobshavn Isbræ, the fastest Greenland ice stream, has disintegrated since 2002, resulting in a doubling of ice velocity and rapidly lowering inland ice elevations. Conditions prior to disintegration were modeled using control theory in a plane-stress solution, and the Missoula model of ice-shelf flow. Both approaches pointed to a mechanism that inhibits ice flow and that is not captured by either approach. Jamming of flow, an inherent property of granular materials passing through a constriction (Jakobshavn Isfjord), is postulated as the mechanism. Rapid disintegration of heavily crevassed floating ice accompanies break-up of the ice jam

Ice Dynamics Preceding Catastrophic Disintegration of the Floating Part of Jakobshavn Isbrie, Greenland

The floating terminal of Jakobshavn Isbr ae, the fastest Greenland ice stream, has disintegrated since 2002, resulting in a doubling of ice velocity and rapidly lowering inland ice elevations. Conditions prior to disintegration were modeled using control theory in a plane-stress solution, and the Missoula model of ice-shelf flow. Both approaches pointed to a mechanism that inhibits ice flow and that is not captured by either approach. Jamming of flow, an inherent property of granular materials passing through a constriction (Jakobshavn Isfjord), is postulated as the mechanism. Rapid disintegration of heavily crevassed floating ice accompanies break-up of the ice jam

The Relationship between Real-Time EEG Engagement, Distraction and Workload Estimates and Simulator-Based Driving Performance

Identifying potentially impaired drivers is often dependent upon using cognitive testing from a controlled environment (clinic, laboratory) to predict behavior in a dynamic and unpredictable real world driving environment. The goal of this study was to determine the feasibility, and validity, of using a wireless EEG system to ultimately differentiate between impaired and unimpaired drivers. We utilized the B-Alert X10 portable wireless EEG/ECG system and applied previously validated EEG algorithms estimating engagement, workload, and distraction within a sample of normal control (n = 10) and HIV seropositive individuals (n = 14). Participants underwent a 30-minute fully interactive driving simulation. Overall, the HIV+ group evidenced significantly higher distraction during the simulation. When grouped according to poor and good performers on the simulation (regardless of HIV serostatus), those performing worse on the simulation had higher distraction, with a trend for lower workload, levels. We then examined EEG profiles immediately preceding a crash. Prior to a crash, participants evidenced a significant increase in distraction ~ 10-14 seconds leading up to the crash; the greatest increase was seen in the HIV+ group. These preliminary data support the potential utility of using EEG data in patient populations to identify individuals who might be at risk for impaired drivin