Mathematical models for acoustical pollution prognosis at signalized intersections

Noise related problems are increasing worldwide with detrimental effects on health and quality of life[18]. The regulations and laws of European Union and Lithuania emphasize the importance of noise reduction, the necessity to collect and disseminate information related to traffic flow, the development of traffic flow mathematical models and their implementation for noise evaluation. In this paper, mathematical methods are applied to determine the noise intensity. Measurements of urban traffic noise were performed at the arterial street intersections in Kaunas ant its suburbs. At this location traffic flow rates are high and noise is dominated by low frequencies. It was determined that the LAeq levels decrease continuously till the end of cycle of the green traffic signal. The developed methodology can be used to estimate traffic noise levels in a city and country districts using data provided by the automated traffic flow registration system. The aim of the article is to develop the mathematical model of a longitudinal noise sources and to apply it for the prediction of acoustical pollution in an environment of roads and streets intersections

Prognostics of vibration induced risk to operators of agricultural machinery

Frequent use of vibrating hand-held tools and operation of machinery can result in various chronic diseases. Operators of machinery are often afflicted with peripheral and systematic disorders. The statistical data collected over several decades clearly indicate the lack of operator’s safety from exposure to vibrations. The causes and impacts of vibration effects on humans are reviewed in annual reports by health and safety experts in many countries. One of the most common occupational diseases that has been frequently reported is the musculoskeletal disorder due to extended exposure to mechanical vibrations. The influence of vibrations during time period τ can be described by vibro-energy load aτ2·τ. If this load value over a specified time period does not exceed the permissible level a2·T0, it will not induce negative effects on human health. This approach was used in the present study for the prediction of hands and whole body vibration effects on operators of various vibration inducing machinery. Agricultural operators were selected as test subjects, since agricultural tractors and other mobile machinery emit high levels of vibration. Vibration data were obtained from statistical reports developed in the time period from 1988 to 2008. It was found that majority of agricultural machinery does not guarantee proper vibration safety. Thus organizational prevention methods should be developed and implemented. Reduction of vibrations by various technical methods and/or reduction of vibration exposure could be costly, but they are needed in order to provide effective solutions in reducing vibration risk to operators

Investigagation of vibrations of variable cross-section linking elements

The applicability of analytical models for vibrations of variable cross-section two- layered cylindrical structural elements is investigated. Natural frequencies of longitudinal and lateral vibrations are calculated and validated experimentally. Natural frequency )( 0 n ? dependence on material properties (?, E) and geometric parameters (l, R, r, S) of structural element provide means for optimization of vibration amplitude characteristic

Population genomics of Bronze Age Eurasia

© 2015 Macmillan Publishers Limited. All rights reserved.The Bronze Age of Eurasia (around 3000-1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought

Population genomics of Bronze Age Eurasia

© 2015 Macmillan Publishers Limited. All rights reserved.The Bronze Age of Eurasia (around 3000-1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought