Actinium is element number 89, and first of the actinide series. This video is one of the 118 clips included in the periodic table of elements themed collection created by Brady Haran and the University of Nottingham in the UK.
Students construct rockets from balloons propelled along a guide string. They use this model to learn about Newton's three laws of motion, examining the effect of different forces on the motion of the rocket.
In this video Paul Andersen explains how the activation energy is a measure of the amount of energy required for a chemical reaction to occur. Due to the collision theory the activation energy requires proper energy and orientation of the colliding molecules.
As emissions of heat-trapping bases accumulate in our atmosphere, Earth's polar regions are warming more quickly than at lower latitudes. The rapid environmental changes that result from this warming can have a significant impact on the physical and mental health of rural Alaskans: unpredictable weather and changes in the seasons have made harvesting food more difficult, hazardous, and stressful. The risk of physical injury has also increased, as poor ice, extreme weather, and coastal erosion bring new travel hazards. Increasingly difficult harvest conditions for fish, shellfish, berries, caribou, and sea mammals have also increased concerns about food security. Additionally, declines in snow pack, the threat of drought, changes in lake and river conditions, and damage and disruptions to community water systems have prompted concerns of water security. The climate-related challenge faced by Alaskas tribal health system is to recognize new health stressors and community vulnerabilities, and then find healthy adaptation strategies in an increasingly uncertain future.
In 2012, water managers in Fredericktown, Missouri, saw their city's main source of water dwindle. They used the EPAs Climate Ready Water Utilities program to consider options and develop plans to protect their water source.
This course will focus for a large part on MOSFET and CMOS, but also on heterojunction BJT, and photonic devices.First non-ideal characteristics of MOSFETs will be discussed, like channel-length modulation and short-channel effects. We will also pay attention to threshold voltage modification by varying the dopant concentration. Further, MOS scaling will be discussed. A combination of an n-channel and p-channel MOSFET is used for CMOS devices that form the basis for current digital technology. The operation of a CMOS inverter will be explained. We will explain in more detail how the transfer characteristics relate to the CMOS design.
This course is about the electronic properties of materials and contains lectures about scattering, transport in metals, phonons and superconductivity.
In this lesson, students learn about work as defined by physical science and see that work is made easier through the use of simple machines. Already encountering simple machines everyday, students will be alerted to their widespread uses in everyday life. This lesson serves as the starting point for the Simple Machines Unit.
Our human society consists of many intertwined Large Scale Socio-Technical Systems (LSSTS), such as infrastructures, industrial networks, the financial systems etc. Environmental pressures created by these systems on EarthŰŞs carrying capacity are leading to exhaustion of natural resources, loss of habitats and biodiversity, and are causing a resource and climate crisis. To avoid this sustainability crisis, we urgently need to transform our production and consumption patterns. Given that we, as inhabitants of this planet, are part of a complex and integrated global system, where and how should we begin this transformation? And how can we also ensure that our transformation efforts will lead to a sustainable world? LSSTS and the ecosystems that they are embedded in are known to be Complex Adaptive Systems (CAS). According to John Holland CAS are "...a dynamic network of many agents (which may represent cells, species, individuals, firms, nations) acting in parallel, constantly acting and reacting to what the other agents are doing. The control of a CAS tends to be highly dispersed and decentralized. If there is to be any coherent behavior in the system, it will have to to arise from competition and cooperation among the agents themselves. The overall behavior of the system is the result of a huge number of decisions made every moment" by many individual agents. Understanding Complex Adaptive Systems requires tools that themselves are complex to create and understand. Shalizi defines Agent Based Modeling as "An agent is a persistent thing which has some state we find worth representing, and which interacts with other agents, mutually modifying each otherŰŞs states. The components of an agent-based model are a collection of agents and their states, the rules governing the interactions of the agents and the environment within which they live." This course will explore the theory of CAS and their main properties. It will also teach you how to work with Agent Based Models in order to model and understand CAS.
Paul Andersen describes the pros and cons of industrial agriculture including: monocropping, irrigation, and the use of pesticides, fertilizers, and GMOs.
This presentation aims to increase the students’ knowledge about environmental epidemiology, by introducing different study designs used to study health effects of exposure to outdoor air pollution. All study designs are illustrated by examples, starting with the Great Smog (Killer Fog) of London in 1952, one of the landmarks in environmental epidemiology.
Nearly one third of the world’s population are exposed to high levels of indoor air pollution from the household’s use of solid fuel. The fuel is mainly biomass burning under poor combustion conditions
in open fires or primitive stoves and with low ventilation. This costs more than 4 million lives every year and enormous suffering in particular among women and children.
What is air pollution? What is it in the air that is harmful? This lecture focuses on air pollution, where it occur, and how it spread.
In this presentation, we will describe the global levels and trends in major air pollutants and related health burden. Air pollution is an important global risk factor for disease. People who live in more polluted areas develop more often chronic and infectious disease and die prematurely as compared to people living in areas with low air pollution.
In large part of the World, people spend more than 90 percent of the time in indoor environments, where air quality is important for health. The environment outside the building, what goes on inside the building and the exchange of air pollutants affects the indoor air. Tight buildings can reduce energy consumption and entry of outdoor air pollutants, but unless ventilation is right indoor air pollutants from combustion processes, dampness, microbes, the dwellers bio effluents,
appliances, care and cleaning products, clothing, furniture, building materials, the underground and many other sources will build up indoors causing important health effects.
In this presentation, we will discuss how we can know whether one individual is more susceptible to harmful effect of air pollution than others are. Everyone is exposed, but some groups may be more susceptible to the harmful effect of air pollution than others may.
In this lecture, we will describe the mechanisms by which air pollution causes pulmonary health effects in the human population. The pulmonary health effects include exacerbation of asthma and chronic obstructive pulmonary diseases (COPD), increased risk of lower
respiratory tracts infections and lung cancer.
In this presentation, we will describe the mechanisms by which air pollution causes health effects in other parts of the body than the lungs. In continuation of this, we will discuss the important mechanisms of extra pulmonary health effect.
There is a long way before the whole world complies with the WHO guidelines for air quality, but the enormous burden of disease from outdoor air pollution forces us to increase action to come as far as possible. In continuation of this, we will discuss what we can do about air pollution at global, international, national, city and individual levels. Most of the actions to reduce air pollution also mitigates climate change and/or promote health in other ways – so there are many win-win and
win-win-win situations
How long of a runway does as a380 need