Midterm! Flashcards
Commit this nonsense to memory.
Entropy
The Second Law of Thermodynamics (Energy spontaneously tends to flow only from being concentrated in one place to becoming diffused or dispersed & spread out). A measure of the amount of energy which is unavailable to do work.
Element
Substance that cannot be decomposed into simpler substances.
Compound
Substance formed by the combination of elements fixed in proportions.
Atom
Smallest part of an element that can ever exist consisting of a dense nucleus of protons and neutrons surrounding by moving electrons.
Molecule
The simplest structural unit that displays the characteristic physical and chemical properties of a compound.
Ion
Atom or group of atoms that has lost one or more electrons making it positively charged (cation) or gained one or more electrons making it negatively charged (anion).
Chemical Bond
Strong force of attraction based on transfer or sharing of electrons that holds atoms together in a molecule.
Chemical Reaction
Change in which one or more chemical elements or compounds form new compounds.
Durability and performance of a material determined by what factors?
Density Porosity Permeability Absorption Adsorption Strength Thermal Properties Acoustic Properties Frost Resistance Soluble Salt Content Chemical Resistance Fire Resistance Susceptibility to Deformation Susceptibility to Deterioration and Decay Natural and Production Defects Appearance
Cellulose
Wood
Crystalline polysaccharide consisting of a long unbranched chain structure of glucose units; responsible for providing rigidity of the cell wall; represents approx. 45-60% of the dry weight of wood.
Hemicellulose
Wood
Semi-crystalline polysaccharide consisting of a shorter chain structure; represents approx. 10-25% of the dry weight of wood.
Lignin
Wood
A complex amorphous organic polymer deposited within the cellulose of plant cell walls; lignification makes the walls woody and therefore rigid; represents approx. 20-35% of the dry weight of wood; greater proportion present in softwoods than hardwoods.
Igneous Rocks
Formed by the solidification of molten rock material.Coarse or fine grained. Granite, basalt, quartz, feldspars, mica
Metamorphic Rocks
Formed through the alteration of igneous and sedimentary rocks by the action of heat and pressure.Slate, schist, gneiss
Sedimentary Rocks
Formed by the accumulation of rock waste at the Earth’s surface.Coarse, medium, or fine grainedClassified according to origin:- Mechanical- Chemical- Organic Limestone, sandstone
Binder
Material used to form the cementing matrix in mortars, renders and plasters, and which typically is derived from lime, gypsum, or artificial cements. Mixed with sands and aggregates to provide workable product.
Concrete
A mix of binder with sands and other aggregates to form an amorphous material capable of use.
Ferrous Metals
Cast and wrought iron.Composed principally of iron with varying amounts of carbon and other elements. Wrought iron strong in tension.Cast iron is brittle in nature; used in compression for columns.
Non-ferrous Metals
Sheet roof coverings, flashings, weatherings, plumbing.Lead, copper, zinc, aluminum.
Bituminous Products
Asphalt and bitumen; amorphous (non-crystalline).Typically resistant to the passage of water and water vapor. Liable to flow or creep under mechanical stress and soften in response to increase in temperature.
Saturation
Maximum water vapor content in the air
Humidity Ratio
The ratio of the water vapor mass to the dry air mass. [units: lb or kg, or as grains of water vapor] Also called Absolute Humidity or Moisture Content.
Relative Humidity
A measure of how much water vapor air is holding relative to how much water vapor it could hold at that temperature and pressure. The ratio of vapor pressure of water (Pv) (partial pressure at saturation) to the actual partial pressure of water vapor(PH20). Relative Humidity = PH2O / Pv x 100%
Dry Bulb Temperature
The temperature of the air as measured with any common thermometer.
Wet Bulb Temperature
Temperature taken with a sling psychrometer
The sling psychrometer has two thermometers, one of which is covered with a wick that is saturated with water. As the psychrometer swings through the air, water is evaporated from the wick, cooling the thermometer. The thermometer with the wick eventually reaches a stable temperature, which is referred to as the wet bulb temperature. The drier the air, the greater the difference between the wet and dry bulb temperatures will be.
Dry Bulb Temperature
The temperature of the air as measured with any common thermometer.
Dew Point Temperature
A temperature at which the water vapor begins to condense. (also: temp at which air becomes completely saturated)
Humid Volume
The total volume of the humid air per unit mass of bone dry air. This quantity may be expressed as either cubic feet per pound of dry air, or cubic meters per kilogram of dry air.
Enthalpy
The enthalpy of humid air is a measure of its heat content. When the air is less than 100% relative humidity, its enthalpy will be lower than if it were saturated. Energy/Mass of Dry Air = Btu/lb Dry Air
Unconsolidated Deposits
Material derived from the disintegration of consolidated rocks. The material consists in different types of unconsolidated deposits of particles of rocks or minerals ranging in size from fractions of a millimeter (clay size) to several meters (boulders). Those important in ground-water hydrology include,
in order of increasing grain size, clay, silt, sand, and gravel. also includes fragments of shells of marine organisms.
Consolidated Rocks
These consist of mineral particles of different sizes and shapes that have been welded by heat and pressure or by chemical reactions into a solid mass. Commonly referred to as bedrock. They include sedimentary rocks that were originally unconsolidated and igneous rocks formed from a molten state. Those important in ground-water hydrology include limestone, dolomite, shale, siltstone, sandstone, and conglomerate . Igneous rocks include granite and basalt.
Primary Openings
Voids formed at the same time as the rock. The pores in sand and gravel and in other unconsolidated deposits are primary openings. Also lava tubes and other openings in basalt.
Secondary Openings
Voids formed after the rock was formed. These include fractures in granite and in consolidated sedimentary rocks are secondary openings. Voids in limestone, which are formed as ground water slowly dissolves the rock, are an especially important type of secondary opening.
Ground Water Hydrology
A subdivision of the science of hydrology. Deals with the occurrence, movement, and quality of water beneath the Earth’s surface.
Semi-Consolidated Rocks
Rocks in which openings include both pores and fractures–both primary and secondary openings.
Unsaturated Zone
The zone which occurs immediately below the land and contains both water and air. This zone can be divided into three parts: the soil zone, the intermediate zone, and the upper part of the capillary fringe.
Saturated Zone
Almost always immediately under the unsaturated zone and where all interconnected openings are full of water.
Capillary Fringe
The subzone between the unsaturated and saturated zones. Results from the attraction between water and rocks.
Water Table
The level in the saturated zone at which hydraulic pressure is equal to atmospheric pressure and is represented by the ater level in unused wells.
Specific Yield
Water in storage in the ground that will drain under the influence of gravity. Tells how much water is available for man’s use.
Specific Retention
The part that is retained as a film on rock surfaces and in very small openings. Tells how much water remains in the rock after it is drained by gravity.
Watterlogged
Where the water table is at a shallow depth, the land may become “waterlogged” during wet weather and unsuitable for residential and many other uses
Latent Energy
A significant change in energy content that must occur before moisture changes state
Adsorption
The process whereby many surfaces in contact with water vapor molecules have the tendency to capture and hold water molecules because of the polar nature of the water molecule. summary: liquid water is ABsorbed into capillary pores, and significant amounts of water vapor can be ADsorbed to the surface of pore walls.
Hydrophobic
Materials that repel water
Hydrophilic
Materials that have the tendency to capture and hold water molecules. Most building materials are this way due to being porous and having very large internal surface areas.