Developments in land mobile satellite service in Europe

The evolution of land mobile radio has reached a stage to benefit from satellite communications. The provision of a service on a pan-European basis makes the use of satellites a viable proposition. The paper describes the European position on both system and space segment aspects of the land mobile satellite service. Also, some of the functions of the European institutions, such as the European Telecommunications Standards Institute (ETSI), the Conference of European Postal and Telecommunications Administrations (CEPT), and the Commission of European Communities (CEC), in establishing these services are identified

Prebisch-Singer Redux

In light of ongoing concern about commodity specialization in Latin America, this paper revisits the argument of Prebisch (1950) that, over the long term, declining terms of trade would frustrate the development goals of the region. This paper has two main objectives. The first is to clarify the issues raised by Prebisch and Singer (1950), as they relate the commodity specialization of developing countries (and Latin America in particular). The second is to reconsider empirically the issue of trends in commodity prices, using recent data and techniques. We show that rather than a downward trend, real primary prices over the last century have experienced one or more abrupt shifts, or “structural breaks,” downwards. The preponderance evidence points to a single break in 1921, with no trend, positive or negative, before or since.

Economic orthodoxy and the East Asian crisis

It is now clear that the economic crisis that struck East Asia so suddenly and violently at the end of 1997 has irrevocably altered the political and economic landscape of the region. Major Asian companies have gone bankrupt, anxious domestic and foreign investors have relocated vast amounts of capital abroad, interest rates have skyrocketed, and inflation and unemployment have soared. At the same time, the economic crisis has also led to the collapse of several governments within the region. In South Korea, an opposition party led ..

Evaluation of brick kiln performances using computational fluid dynamics (CFD)

Modern history of civilization is concurrent to the use of brick and its manufacturing. Nowadays tunnel kiln is the most widely used technology for brick production. This paper tries to provide an idea of the brick making process in tunnel kiln. The computational fluid dynamics (CFD) software, ANSYS CFX is being used to evaluate kiln performances using gas as its fuel. Simplified geometry was drawn and meshed using appropriate tools of ANSYS CFX. Several pertinent assumptions were made to reduce the complication of the simulation. Turbulence, combustion, radiation and NO models were adopted for simulation of a realistic tunnel kiln environment. Simulated temperature profile almost replicates industrial kiln situation as found in existing literature. CFD analysis helps to simulate the temperature profile of the brick kilns, the mass flow fractions of CO2 and NO emissions at outlet, and also the air velocity profile inside the kiln. The simulated temperature generated in a tunnel kiln is found to be between 1300 K and 300 K. CO2 and NOx volume generated inside the kiln is estimated as 1.01 m3/s and 0.108 m3/s respectively

Lattice Green functions and diffusion for modelling traffic routing in ad hoc networks

We describe basic properties of Markov chains on finite state spaces and their application to Green functions, partial differential equations, and their (approximate) solution using random walks on a graph. Attention is paid to the influence of boundary conditions (Dirichlet/von Neumann). We apply these ideas to the study of traffic propagation and distribution in ad hoc networks

Covid-19 and Emergency Medicine: A Scientometric Assessment of Global Publications

This study analyses Covid-19 and Emergency Medicine research output during 2020-2021 on different parameters including global publications share, citation impact, contribution of authors and patterns of research communication in most productive and preferred journals. Web of Science Citation Database has been used to retrieve the data for 2 years (2020-2021) with 991 publications using the combined search of Covid-19 with topic field and Emergency Medicine with using Web of Science Subject Categories. The USA tops the list, with a publications share of 38.6%(383) followed far by Italy and UK ranks second with 7.7%(76), Canada with 7.6% and India ranks 14th positions with global publications share of 1.7 %(17)). The most productive Institutions are: Harvard Medical University lead with 34 Publications and received 134 Citations followed by University Toronto with 29 (96 Citations), Massachusetts Gen Hospital with 26 (86 Citations), Monash University with 22 (92 Citations), Columbia University and University Ottawa with 18 publications. The top most 5 preferred Journals are: AMERICAN JOURNAL OF EMERGENCY MEDICINE (IF: 1.70 with 141 publication followed far by ANNALS OF EMERGENCY MEDICINE (IF: 5.35) with 97 publications, RESUSCITATION (IF: 4.57) with 77, WESTERN JOURNAL OF EMERGENCY MEDICINE (IF: 1.80) with 71 and EMERGENCY MEDICINE JOURNAL (IF: 2.04) with 64. But its average annual publication growth rate and global publication share is high and Citation quality as reflected in Average Citations Per Paper is less. Concludes that the research needs to increase its output and bring about improvement in the quality of its research efforts. This can be done by investing much more international collaboration and by modernizing and strengthening its research infrastructure in the field of Medicines

The role of achievement goal orientation in the development of self efficacy during computer training

Computer self-efficacy (CSE) is a key factor that is related to performance in computer training. A study was conducted to understand the effects of achievement goal orientation on computer self efficacy development with 166 trainees using a database application. Results show that trainees with different achievement motivation dispositions have affects on CSE development through different paths. Individuals with high mastery approach and performance approach dispositions have positive effects on pre training CSE. Mastery avoidance disposition increases Computer Anxiety (CA), this is not seen with performance avoidance. Performance approach affects CSE development by increasing effort. The study provides initial evidence for the need for targeted interventions on CSE and CA, based on trainees’ goal orientation as a personality trait

Computational Modeling of Smoldering Combustion in Wildland Fuels

Smoldering combustion in wildland fires is a critical phenomenon that needs in-depth study because it can initiate with weaker ignition sources, can persist for long periods, is difficult to suppress, and can transit to flaming combustion. Cellulose, hemicellulose, and lignin are the major organic constituents within biomass, in varying proportions based on the type of fuel. The goal of this study is to computationally model and analyze smoldering combustion in mixtures of these constituents that represent real forest fuels. Smoldering combustion is modeled using a kinetic scheme that involves kinetic parameters and thermophysical properties. These data can vary depending on the source and the experimental setup used for measurements. Variations in input parameters significantly impact the output calculations. An uncertainty analysis estimated uncertainties associated with these inputs while a sensitivity analysis identified which parameters have higher influence on outputs. Kinetic properties are highly sensitive to the behavior of smoldering combustion and uncertainties associated with them are lower. In contrast, physical properties have higher uncertainties associated and are less sensitive to smoldering behavior. Further, fuel composition, density, oxygen concentration, and moisture content affect smoldering behavior, including propagation speed and peak temperature. Increases in lignin content decrease the propagation speed, while increasing hemicellulose content raises the propagation speed due to variations in rates of pyrolysis. Peak temperature rises with both increasing lignin and hemicellulose content, caused by the formation of ash. When the density of a mixture increases, propagation speed decreases and peak temperature rises. Accurately modeling smoldering in a given fuel requires characterizing whether moisture content causes expansion. In the context of smoldering ignition, radiative heat sources and hot metal particles can ignite a fire. Chemical kinetics drive the ignition via radiation, while physical properties drive ignition from conduction. Thus, fuels with varying physical and chemical characteristics will behave differently under different ignition sources. The insights gained from the model and these studies act as a novel framework for predicting smoldering combustion of forest fuels in wildland fires

A Scientometric Analysis of Highly Cited Works on Herbal Drugs, Medicines and Vaccines

The present study aims to analyse the research output performance on Herbal Drugs, Medicines and Vaccines. A total of 973 research articles published in Web of Science database were analysed to find out the performance of Herbal Medicines, Drugs and Vaccines developers from all over the world in terms of growth of Publications and Citations impact during the period 1989-2021. Global publication shares, prolific author in the field, high productive Institutions, Journals, are studied in this article. The top most cited countries are: USA with 64799 Citations for 288 (29.6%) Publications followed by People R China with 29264 Citations for 185 (19%) Publications, UK with 22700 Citations for 112 Publications, Germany with 11522 Citations for 65 publications. India recorded 11859 Citations for 61 publications. The most productive institutions were: University Exeter (29), Harvard University National University of Singapore, Chinese Academy of Science and so on. The most Cited Institutions are: Harvard University with 9428 Citations for 22 Publications followed by Beth Israel Deaconess Med Ctr with 6476 Citations for 10 Publications, University of Exeter with 5411 Citations for 29 Publications. The most cited Paper is “Eisenberg DM, Davis RB, Ettner SL, Appel S, Wilkey S, et al., Trends in alternative medicine use in the United States, 1990-1997 - Results of a follow-up national survey, JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION. 1998 NOV 11; 280 (18): 1569-1575” with 4562 Citations. The most Cited journals were: JOURNAL OF ETHNOPHARMACOLOGY topped the list with 17235 Citations for 101 Publications followed by JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION with 7614 Citations for 8 Publications, PHYTOTHERAPY RESEARCH with 4761 Citations for 21 Publications. It noted that researcher has given the preference to highly impact Journals for their publications