ENVIRONMENTAL SCIENCE AND TECHNOLOGY
CHAPTER 16
Main Points Covered By Chapter 16
The Earth as made by humans
Anthrospheric constructs, flows, and conduits Infrastructure
Transportation Communications
Technology and Engineering Acquisition of raw materials Agriculture
Industries
Materials science Automation
Robotics
Computers and technology Nanotechnology
The anthrosphere, that part of Earth made and operated by humans, strongly influences, and is strongly influenced by the geosphere, hydrosphere, biosphere, and atmosphere
The remainder of this book deals with the anthrosphere • What it is • What it does • Its effects
Necessary to consider the technological, engineering, and industrial aspects of human activities in the anthrosphere
The anthrosphere includes
16.1. The Earth As Made By Humans
• Anthrospheric constructs including dwellings, factories, commercial centers, mines
• Anthrospheric flows of materials, energy, communications, people
• Anthrospheric conduits for the transmission of materials, energy,
Illustration of Constructs, Flows, and Conduits in the
Atmosphere
constructed by humans
Natural gas well
Gas pipeline,
a conduit
Flow of material,
natural gas
In more affluent societies there has been a large increase in home size and amenities
• More comfort • More energy consumed • More land occupied Homes and other buildings can be designed, constructed, and operated much more sustainably
• Smaller scale • Renewable materials • Energy efficiency
Continuous flows throughout the anthrosphere • Materials • Energy • Information • People
• A measure of prosperity in conventional economic terms
Reduction of flows of materials, energy, and people is one of the most effective ways to enhance sustainability
• Dematerialization to reduce energy flows • Greater energy use efficiency
• Reduce need for people to commute
Anthrospheric conduits are the means by which materials, energy, people, and communications are moved
Anthrospheric conduits have large sustainability/environmental impacts
• Highways, streets, parking lots cover large areas
Railroads, pipelines, underground electrical and communications cables are generally more sustainable alternatives for anthrospheric conduits
Infrastructure consists of utilities, facilities, and systems used in common by members of a society and upon which it depends
• Physical components: Roads, bridges, pipelines
• Instructions: Laws, regulations, operational procedures Some major infrastructure components
• Transportation systems including railroads, highways, air transport • Energy generating and distribution systems
• Buildings
• Telecommunications systems
• Water supply and distribution systems • Waste treatment and disposal systems
Good utilities, water supply systems, waste treatment systems, and energy systems minimize pollution and energy consumption
Better materials and improved design have enhanced infrastructure • Less material used in infrastructure elements
• Less energy consumed by infrastructure
Enormous improvements in communications infrastructure • Solid state electronics • Computer control • Fiber optics Needed improvements in transportation infrastructure
• Less energy consumption
• Less pollution, such as by replacements for private autos
Early transportation advances
• The wheel • Domestication of “beasts of burden” • The sail for water craft
Transportation advances from the 1800s
• Steamships • Steam-powered rail transport Transportation advances from the 1900s
• Internal combustion engine enabling motor vehicles and aircraft Effects of modern transportation practices, especially motor
vehicles
• Alteration of landscape for highways • Pavement of vast areas
• Air pollution
• Exhaustion of petroleum supplies
Computerized engine systems for more efficient, less polluting transport
Advanced air traffic control systems for more efficient movement of people by air
Mixed modes of transport
• People moved long distances by air, to local destinations by rail • Freight moved long distances by rail, then by truck
A systems approach enables favorable tradeoffs among speed, energy consumption, noise, pollution, convenience
The telecommuter society enables people to work at or near their
homes communicating through computers and high-speed modes of communication
• Conserves energy • Saves time • Reduces pollution
The major areas to consider with respect to communication are • Acquisition • Recording • Computing • Storing • Displaying • Transmission
16.7. The Communications Revolution
1. Information taken in and
translated to a form
able for transmission
2. Information transmitted
3. Information received
and displayed
Illustration of the transmitter, the medium, and the receiver in communication
Photonics: Optical Communication Using Optical Fibers
Transmitter
Repeater
Receiver
Humans employ the anthrosphere to provide for their needs • Goods: Food, shelter, clothing
• Services: Transportation, communications
Engineering uses fundamental science to provide people with the plans and means to accomplish practical objectives
Technology employs designs and plans from engineering to accomplish objectives
• Manufacturing consumer goods • Moving people and goods
• Minimizing environmental impact
Technology pre-dating Greek and Roman eras
• Metallurgy starting with copper around 4000 B.C.
• Wheel • Domestication of the horse • Architecture • Canals • Writing for communication
Development of machines from ancient Greece, Rome, China
• Windlass • Pulley • Inclined plane • Water wheel • Wooden gears Tremendous technological developments in 1800s
• Steam power • Railroads • Telegraph • Telephone • Electricity Technology since about 1900
• Increased energy use • Increased manufacturing speed • Increased communication speed • New chemicals
• Synthetic polymers • Electronics (vacuum tube)
Civil engineering largely involves anthrospheric structures, such as roads, on the geosphere and is very important in sustainability
Mechanical engineering deals with machines and how they handle forces, motion, and power
• Has enabled development of much of the anthrosphere
Electrical engineering is concerned with the generation, transmission, and utilization of electrical energy
• Good electrical engineering can lead to environmental benefits • Increased efficiency • Buried electrical lines
Electronics engineering deals with electromagnetic radiation and electron behavior, such as in silicon integrated circuits
• Great current and potential contribution to sustainability
Chemical engineering is used to design and operate processes that generate products and materials through controlled chemical
reactions
• Key to sustainable “green chemical” processes • Importance of catalysis in green processes
Acquisition and processing of materials have a number of environmental implications
• Effects of mining are especially important
• Processing can leave large quantities of wastes needing disposal
Raw materials are substances required for manufacturing
• From extractive (nonrenewable) sources: Minerals, petroleum • From renewable sources: Wood, plant fibers, plant oils, cellulose
Mining
• Surface, often complicated by surface disturbance
• Underground: Problems include subsidence, groundwater harm
Placer deposits of minerals from running water • Mined with water under pressure
Agriculture provides food for humans
• Crops to produce grain, fruit, vegetables, fiber, oils
• Livestock to produce meat milk, and other animal products Agriculture is based upon domestic species developed and improved from wild ancestors
• Hybrids, use of fertilizers, selective breeding great improvement Agriculture has great effects on other environmental spheres
• Large part of geosphere to anthrosphere
Effects of industrialization and development on agriculture • Cropland is lost
• Consumption of livestock products needing cropland increases Sustainable agriculture
• Soil conservation • Low tillage agriculture
Future challenge for agriculture is to provide materials now obtained from petroleum
• Ethanol fuel from corn
An industry is an enterprise that makes a kind of goods or provides a service needed by humans for their existence and well-being
Kinds of industries depend upon many factors such as
• Raw materials • Human resources • Availability of transport Kinds of industries include
• Food production • Extractive minerals • Renewable energy • Extractive energy • Manufacturing • Construction • Utilities • Communications • Transportation • Wholesale/retail trade • Finance • Services • Government
(1) Traditional devoted to basic needs of food and shelter (2) Preconditions for takeoff
(3) Takeoff, growth and investment in industrial development
(4) Drive to maturity, industrial base becomes mature and diversified (5) Age of high mass consumption
• High consumption of consumer goods • Large service industry
Manufacturing: The Industrial Process
Energy
Transportation
Communication
Processing
raw material
to finished
material
Raw material
from extractive
sources
Fabrication and assembly
of product
Raw material
from renewable
sources
Finished
material
Recycling and disposal
Recycled
material
Consumer
Product distribution
Spent product
Materials science deals with the composition, properties, and
applications of substances used to make devices, machines, and structures
Kinds of materials
• Metals • Plastics • Wood • Glass • Concrete • Ceramics Characteristics considered include
• Strength • Weight • Flammability • Costs • Sustainability
Polymers have very large molecules made from smaller monomers Natural polymers include cellulose, lignin, wool
Synthetic polymers include plastics (polyethylene), fibers in textiles, synthetic rubber, epoxy resins
Elastomers that flex and stretch (rubber)
Green polymers come from renewable sources and are
biodegradable
Ceramics are inorganic materials involving ionically bound
constituents, usually silicon and oxygen, but may be carbides, nitrides, and borides or contain aluminum
• Usually formed by high temperature processes
• Usually hard, rigid, resistant to heat and chemical attack • Raw materials include clays, feldspar, synthetic chemicals Ceramics have many uses
• Refractory bricks • Electrical materials • Semiconductors • Composites
Sustainability of ceramics
• Usually from abundant minerals
• Substitute for scarce metals in some cases
Composites are composed of two or more materials, usually high-strength reinforcing materials imbedded in a matrix
Composites have better overall properties of strength, electrical resistance/conductivity, cost, other properties superior to those of constituents
Materials in composites
• Organic polymers • Inorganic substances • metals/alloys Composites have many forms
• Fibers • Rods • Particles • Porous solids • Sheets
Composite matrix may be metal, plastic, ceramic, other moldable material
Reinforcing materials are fibers of substances such as glass, graphite fibers, metal wires, other
Automation uses machines working automatically and repetitively in tasks repeated multiple times and employing electromechanical
devices to replace or extend human activities
Mechanization uses a machine to increase strength, speed, precision of human activities
Open-loop multifunctional devices perform tasks according to preset instructions
Closed-loop multifunctional devices use process feedback information to continuously adjust a process
Artificial intelligence uses simulated reasoning Automation can aid sustainability
• Increased fuel economy with automated engines and transmissions • Fewer pollutants produced
• Less worker harm in dangerous or repetitive tasks • Less wasted material
Automated Feedback Control System
Comparison of
output to input
Output
InputSensors
Process
Robotics is an extension of automation in which a machine mimics human activities through physical movement
A robot is a multifunctional device that can perform a variety of tasks following pre-programmed instructions
Robots use mechanical manipulators in which low-energy signals passing through servomechanisms perform tasks requiring
substantial strength
The “brains” of a robot consist of a computer that is
pre-programmed or that has learned tasks by following motions of the robot carried out by humans
Robots enable technologies that cannot be performed readily or at all by humans
• Work continuously in unhealthy, dangerous surroundings • Do repetitive motions that harm humans
• Perform in high-radiation environments • Work in dangerous mines
• Work in mineral deposits below where humans can function
Computers are everywhere in modern technology
Computer-aided design (CAD) is used to convert an idea to a manufactured product
• Provide a picture of the final product
• Analyze various facets of the product before it is made • Enable facile redesign
Computer-aided manufacturing (CAM)
• Plan and control manufacturing operations • Quality control
• Manage entire manufacturing plants
Computer-aided design and manufacturing combined, CAD/CAM Computers in green technology
Micromachines are devices as small as around 1 millimeter in size • Example: Microcameras for health diagnoses
Microelectromechanical devices (MEMS) made by processes used for making integrated circuits (microchips)
A working model of a 1936 Toyota compared to a matchstick that has 24 working parts and can travel up to 5 millimeters/second
Nanotechnology refers to devices the size of a nanometer (nm) and
nanoscience is the science of the extremely small
The nanorealm deals with materials and systems in which at least one dimension is 1 to 100 nm, are governed by physical and chemical
properties of molecules on a molecular size scale and can be connected to form larger entities
Nanostructures can be fabricated from bulk materials, but it is more promising to build them up from molecules
Nanotechnology in green science and technology • Better, more specific catalysts
• Nanomebranes with specific porosity, surface properties, chemistry • Devices from far less material using much less energy
High technology, commonly called “high tech,” entails many modern technologies
• Voice synthesis • Artificial intelligence • Lasers • CAD/CAM • Light-emitting diodes • Digital video • Cryogenics • Other
High tech has many applications to green science and technology • High efficiency devices and processes using little energy, material • Advanced photovoltaics for solar energy
• Advanced energy storage devices and materials • Many others
