Isolation and Development

This paper exploits cross-country variation in the degree of geographical isolation, prior to the advent of sea-faring and airborne transportation technologies, to examine its impact on the course of economic development across the globe. The empirical investigation establishes that prehistoric geographical isolation has generated a persistent beneficial effect on the process of development and contributed to the contemporary variation in the standard of living across countries.Growth, Development, Isolation, Agglomeration, Globalization

Models of Jupiter's Polar Aurora

Auroral emissions from Jupiter have been observed across the photon spectrum including ultraviolet and x-ray wavelengths. UV observations suggest an input flux power of 1013 - 1014 W for the aurora in each hemisphere. X-ray emissions with a total power of about 1 GW were observed by the Einstein Observatory, the Roentgen satellite, Chandra x-ray Observatory (CXO), and XMM-Newton. Previous theoretical studies have shown that precipitating energetic sulfur and oxygen ions can produce the observed x-rays. This study focuses on the ion precipitation of the polar region and its effects in the ionosphere. We present the results of a hybrid Monte Carlo model for sulfur and oxygen ion precipitation at high latitudes, look at differences with the continuous slowdown model, and compare the results to synthetic spectra fitted to observations. We concentrate on the effects of altitude on the observed spectrum and find that the opacity of the atmosphere to the outgoing x-ray photons is important for incident ion energies greater than about 1.2 MeV per nucleon for both sulfur and oxygen. Quenching of longer-lived excited states of the oxygen ions is also found to be important. Opacity considerably diminishes the outgoing x-ray intensity calculated, particularly when the viewing geometry is not favorable. We estimate an emission efficiency for the x-ray aurora of &epsilon ~ 7 x 10-5. Secondary electrons from the ion precipitation as well as photoelectrons and auroral electrons also affect the polar cap atmosphere. We calculated the secondary electron production due to the oxygen ion precipitation for the first time. We analyze the secondary electron fluxes due to the ion aurora and estimate their effects on the ionosphere and field aligned electrical currents. We find that the secondary electrons affect the ionosphere similarly to auroral electrons responsible for the diffuse UV aurora and are therefore important for the magnetospheric dynamics and our better understanding of the ionosphere-magnetosphere coupling

Cryptocurrencies and regulations: a comparative framework for international implementations

Purpose- The recent developments in technology have created a remarkable increase in the financial markets. The decentralization of crypto assets and the price movements attract investors attention as an demanding financial instrument. Since the beginning of pandemics, inflation is one of the major macroeconomic issue in the globe that push the investors to seek for new investment opportunities. Perhaps the positive perception regarding the cryptocurrency investment is its protection from inflation. In addition cost-effective mode of transaction and easy transfer of funds make these instruments unique. On the other hand, it can also lead to unsolicited consequences such as money laundering, illegal purchases, and the elimination of corruption. In this context, regulations are being formed to bring crypto assets, which attract the attention of experts, into compliance with the tax and trade-related laws of countries in the financial system. In this study, it is aimed to convey the importance of regulation and regulations on the world. Methodology- Since the first launch of Bitcoin as a cryptocurrency in 2009; the recent discussion came forward on how to regulate this market. Understanding cryptocurrency takes time and effort while they are extremely volatile investment. The crypto money applications of the countries and their taxation and approaches towards these applications have been evaluated by examining the official reports of the countries. Findings- Countries' perspectives on crypto money, the concept and definitions of crypto money vary. Some accept the cryptocurrencies as legal investment tools and draw a legal framework, while some announce that they eliminate these investments. Perhaps developing a framework can help to regulate both actors and also the transactions in the crypto ecosystem. National authorities plan to take a position how technology can be used to create cryptoassets. Conclusion- Regulations are important for making the financial system safe, protecting individual investors and ensuring an orderly environment in enterprises. Countries need to accept the crypto currency system and keep up with the innovations of crypto money by changing the current standards if necessary.Publisher's Versio

Vibration-based condition monitoring of wind turbine blades

Significant advances in wind turbine technology have increased the need for maintenance through condition monitoring. Indeed condition monitoring techniques exist and are deployed on wind turbines across Europe and America but are limited in scope. The sensors and monitoring devices used can be very expensive to deploy, further increasing costs within the wind industry. The work outlined in this thesis primarily investigates potential low-cost alternatives in the laboratory environment using vibration-based and modal testing techniques that could be used to monitor the condition of wind turbine blades. The main contributions of this thesis are: (1) the review of vibration-based condition monitoring for changing natural frequency identification; (2) the application of low-cost piezoelectric sounders with proof mass for sensing and measuring vibrations which provide information on structural health; (3) the application of low-cost miniature Micro-Electro-Mechanical Systems (MEMS) accelerometers for detecting and measuring defects in micro wind turbine blades in laboratory experiments; (4) development of an in-service calibration technique for arbitrarily positioned MEMS accelerometers on a medium-sized wind turbine blade. This allowed for easier aligning of coordinate systems and setting the accelerometer calibration values using samples taken over a period of time; (5) laboratory validation of low-cost modal analysis techniques on a medium-sized wind turbine blade; (6) mimicked ice-loading and laboratory measurement of vibration characteristics using MEMS accelerometers on a real wind turbine blade and (7) conceptualisation and systems design of a novel embedded monitoring system that can be installed at manufacture, is self-powered, has signal processing capability and can operate remotely. By applying the conclusions of this work, which demonstrates that low-cost consumer electronics specifically MEMS accelerometers can measure the vibration characteristics of wind turbine blades, the implementation and deployment of these devices can contribute towards reducing the rising costs of condition monitoring within the wind industry

Nasca classification of hemivertebra in five dogs

<p/> <p>Five dogs, four small mixed breed and a Doberman Pinscher, presented in our clinic with hemivertebra. Complete physical, radiological and neurological examinations were done and the spinal deformities were characterized in accord with the Nasca classification used in human medicine. Two dogs had multiple hemivertebrae (round, oval or wedge-shaped: Type 3) in the thoracic region; one dog had an individual surplus half vertebral body (Type 1) plus a wedge-shaped hemivertebra (Type 2b) in the lumbar region; one dog had multiple hemivertebrae which were fused on one side (Type 4a) in the thoracic region; and one dog had a wedge-shaped hemivertebra (Type 2a) in the cervical region.</p

Condition monitoring of wind turbine blades using MEMS accelerometers

Wind turbine rotors in operation are subject to fatigue which is reflected as cracks and delamination in composite blades. Blade condition monitoring is becoming important to operators and insurers alike as the cost of damaged-blade repairs or replacement is very high and hence, the need for cheaper long-term solutions in the current strives for sustainable energy. In this paper, vibration/modal analysis non-destructive testing (NDT) method was used in conjunction with Signal Processing techniques to investigate the feasibility of integrating low-cost micro electro-mechanical systems (MEMS) accelerometers for blade condition monitoring as an alternative to the conventional piezoelectric accelerometers which are bulky and expensive. A rig-mounted 4.5m long blade from a 25kW Carter wind turbine was retrofitted with five MEMS accelerometers of type ADXL335 and vibration response measurements were recorded and analysed as the blade’s angle of orientation was changed by 10° from 0° to 180°. Results showed that the MEMS accelerometers are capable of measuring the blade response at each set angle of orientation. This shows potential for MEMS accelerometer integration for condition monitoring as in reality, wind turbine blades will continuously be in rotation in order to generate energy. Thus these accelerometers can perform as normal when there is a change in the blade’s orientation. In conclusion, MEMS accelerometers have a great potential to be integrated easily either retrofitted externally or embedded in blades at manufacture for condition monitoring at marginal cost

Nonstandard definition of the stratonovich integral

By using the relation between the Ito integral and the Stratonovich integral, a nonstandard definition of the Stratonovich integral is given