Equivalent factors are factors used to convert quantities from their original physical units into a common accounting unit for the purpose of aggregating energy sources or assessing contributions” to environmental problems from diverse sources (for example, the contribution of different pollutants to global warming).
What is an equivalence factor?
In redox reactions, the equivalence factor describes the number of electrons that an oxidizing or reducing agent can accept or donate. Here, 1 / f eq can have a fractional (non-integer) value. In precipitation reactions, the equivalence factor measures the number of ions which will precipitate in a given reaction.
What is the equivalency factor?
The equivalency factor is based on the quantity of dried cannabis that is required to produce 1 mL of cannabis oil. It takes approximately 1 g of dried flowers to produce 4 mL of cannabis oil.
How to create equivalent fractions?
To find equivalent fractions on a fraction wall:
- Locate the fraction on the fraction wall.
- Draw a vertical line to the right of the fraction.
- Any equivalent fraction will be aligned to this line.
How do you determine whether fractions are equivalent?
- Equivalent fractions may look different, but they have the same value.
- You can multiply or divide to find an equivalent fraction.
- Adding or subtracting does not work for finding an equivalent fraction.
- If you multiply or divide by the top of the fraction, you must do the same to the bottom.
TEQ
Applications
History and development
How do you find the equivalent factor?
Solution : Equivalent factor ( n ) = `( “Molar mass” ( g mol^(-1)))/(“equivalent mass” ( g eq^(-1)))`
The usefulness of this factor is that the equivalent masses of all the substances can be calculated whether it is an acid, base, salt, or an oxidising or reducing agent.
What is number of equivalent?
Equivalent numbers are numbers that have the same value. Each type of number, such as fractions, decimals, or square roots, can be equivalent to other numbers of their types, or to numbers of different types, as long as they have the same value.
What is an acid equivalent?
Acid equivalent may be defined as that portion of a formulation (as in the case of 2,4-D ester for example) that theoretically could be converted back to the corresponding or parent acid.
What are equivalents in chemistry?
An equivalent (symbol: officially equiv; unofficially but often Eq) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount (typically one mole) of another substance in a given chemical reaction.
What is equivalent example?
The definition of equivalent is something that is essentially the same or equal to something else. An example of equivalent is (2+2) and the number 4. Since 2+2= 4, these two things are equivalent. To make equivalent to; to equal.
What equivalence means?
Definition of equivalence 1a : the state or property of being equivalent. b : the relation holding between two statements if they are either both true or both false so that to affirm one and to deny the other would result in a contradiction. 2 : a presentation of terms as equivalent.
What is normality and equivalent weight?
Normality is the number of equivalent weights, EW, per unit volume. An equivalent weight is the ratio of a chemical species’ formula weight, FW, to the number of its equivalents, n. EW=FWn. The following simple relationship exists between normality, N, and molarity, M. N=n×M.
What is equivalent basicity?
“Equivalent acidity” is defined as the acidity developed by a fertilizer when applied to soils, measured in terms of calcium carbonate required for its neutralization. “Equivalent basicity” is defined as the basic residuelef t in soils by fertilization expressed as equivalent calcium carbonate.
What is equivalent weight formula?
Equivalent Weight = Molecular weight/ Valency.
What’s equivalent mean in math?
Equivalent expressions are expressions that work the same even though they look different. If two algebraic expressions are equivalent, then the two expressions have the same value when we plug in the same value(s) for the variable(s).
How do you find the number of equivalence relations?
Number of equivalence relations or number of partitions is given by S(n,k)=S(n−1,k−1)+kS(n−1,k), where n is the number of elements in a set and k is the number of elements in a subset of partition, with initial condition S(n,1)=S(n,n)=1.
What is number of gram equivalent?
Gram equivalent weight is equal to mass in grams numerically equal to Equivalent Weight. To calculate the Gram Equivalent Weight, we use the formula Eq = MW / n. Here we will learn how to calculate the Equivalent Weight Formula of a compound.
Does equivalent mean equal?
Main Difference – Equal vs. Equivalent. Equal and equivalent are terms that are used frequently in mathematics. The main difference between equal and equivalent is that the term equal refers to things that are similar in all aspects, whereas the term equivalent refers to things that are similar in a particular aspect.
How to make a fraction equivalent?
Multiply both the numerator and denominator of a fraction by the same whole number. As long as you multiply both top and bottom of the fraction by the same number, you won’t change the value of the fraction , and you’ll create an equivalent fraction.
What are Equivalent Fractions?
Equivalent fractions are fractions with different numbers representing the same part of a whole. They have different numerators and denominators, but their fractional values are the same.
What is half of a fraction?
For example, think about the fraction 1/2. It means half of something. You can also say that 6/12 is half, and that 50/100 is half. They represent the same part of the whole. These equivalent fractions contain different numbers but they mean the same thing: 1/2 = 6/12 = 50/100
Why are fractions the same?
Why are they the same? Because when you multiply or divide both the top and bottom by the same number, the fraction keeps it’s value.
Can you multiply to get an equivalent fraction?
You only multiply or divide, never add or subtract, to get an equivalent fraction.
What is toxic equivalency?
The toxic equivalency of a mixture is defined by the sum of the concentrations of individual compounds (C i) multiplied by their relative toxicity (TEF):
What is TEF/TEQ?
The TEF/TEQ concept has been developed to facilitate risk assessment and regulatory control. While the initial and current set of TEFs only apply to dioxins and dioxin-like chemicals (DLCs), the concept can theoretically be applied to any group of chemicals satisfying the extensive similarity criteria used with dioxins, primarily that the main mechanism of action is shared across the group. Thus far, only the DLCs have had such a high degree of evidence of toxicological similarity.
Why is additive important in TEF?
Additivity is an important concept here because the TEF method operates under the assumption that the assessed contaminants are dose-additive in mixtures. Because dioxins and DLCs act similarly at the AhR, their individual quantities in a mixture can be added together as proportional values, i.e. TEQs, to assess the total potency. This notion is fairly well supported by research. Some interactions have been observed and some uncertainties remain, including application to other than oral intake.
What is the TEF approach?
The TEF approach uses an underlying assumption of additivity associated with these chemicals that takes into account chemical structure and behavior. For each chemical the model uses comparative measures from individual toxicity assays, known as relative effect potency (REP), to assign a single scaling factor known as the TEF.
What is the TEF of dioxins?
Toxic equivalency factor ( TEF) expresses the toxicity of dioxins, furans and PCBs in terms of the most toxic form of dioxin, 2,3,7,8-TCDD. The toxicity of the individual congeners may vary by orders of magnitude .
What is joint effect?
Joint effects are described as being additive (using dose, response/risk, or measured effect), synergistic, or antagonistic. A dose-additive response occurs when the mixture effect is determined by the sum of the component chemical doses, each weighted by its relative toxic potency.
How are human health risks calculated?
Risks in humans are typically calculated from known ingestion of contaminants or from blood or adipose tissue samples. However, human intake data is limited, and calculations from blood and tissue are not well supported. This presents a limitation to the TEF application in risk assessment to humans.
What is equivalent equation?
Equivalent equations are algebraic equations that have identical solutions or roots. Adding or subtracting the same number or expression to both sides of an equation produces an equivalent equation. Multiplying or dividing both sides of an equation by the same non-zero number produces an equivalent equation.
How to solve two equations with two variables?
Start with the first set. To solve two equations with two variables, isolate one variable and plug its solution into the other equation. To isolate the “y” variable:
What does it mean when you multiply and divide by the same non zero number?
Multiplying or dividing both sides of an equation by the same non-zero number produces an equivalent equation.
What is the difference between the first and second set of equations?
The only difference between the first equation in each set is that the first one is three times the second one (equivalent). The second equation is exactly the same.
Can you use equivalent equations in everyday life?
You can use equivalent equations in daily life. It’s particularly helpful when shopping. For example, you like a particular shirt. One company offers the shirt for $6 and has $12 shipping, while another company offers the shirt for $7.50 and has $9 shipping.
Is it useful to know if an equation is equivalent?
Recognizing these equations are equivalent is great, but not particularly useful . Usually, an equivalent equation problem asks you to solve for a variable to see if it is the same (the same root) as the one in another equation.
What is load equivalency factor?
The equation outputs are load equivalency factors (LEFs) or ESAL factors. This factor relates various axle load combinations to the standard 80 kN (18,000 lbs) single axle load. It should be noted that ESALs as calculated by the ESAL equations are dependent upon the pavement type (flexible or rigid) and the pavement structure ( structural number for flexible and slab depth for rigid). As a rule-of-thumb, the 1993 AASHTO Design Guide, Part III, Chapter 5, Paragraph 5.2.3 recommends the use of a multiplier of 1.5 to convert flexible ESALs to rigid ESALs (or a multiplier of 0.67 to convert rigid ESALs to flexible ESALs). Using load spectra (as proposed in the 2002 G uide for the Design of New and Rehabilitated Pavement Structures) will eliminate the need for flexible-rigid ESAL conversions. Table 1 shows some typical LEFs for various axle-load combinations.
What is the ratio of 7.9 to 1.0?
Comparing the two, the ratio is: 7.9/1.0 = 7.9
Is AASHTO load equivalency easy to remember?
The AASHTO load equivalency equation is quite cumbersome and certainly not easy to remember. Therefore, as a rule-of-thumb, the damage caused by a particular load is roughly related to the load by a power of four (for reasonably strong pavement surfaces). For example, given a flexible pavement with SN = 3.0 and p t = 2.5:
What is the RE factor?
The relative effectiveness factor (RE factor) relates an explosive’s demolition power to that of TNT, in units of the TNT equivalent/kg (TNTe/kg). The RE factor is the relative mass of TNT to which an explosive is equivalent: The greater the RE, the more powerful the explosive.
What is the equivalent of TNT?
TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The ton of TNT is a unit of energy defined by that convention to be 4.184 gigajoules, which is the approximate energy released in the detonation of a metric ton (1,000 kilograms) of TNT.
How many terajoules are in a kiloton?
The ” kiloton (of TNT)” is a unit of energy equal to 4.184 terajoules ( 4.184 × 1012 J ).
What Is the Equivalent Annual Cost (EAC)?
Equivalent annual cost (EAC) is the annual cost of owning, operating, and maintaining an asset over its entire life. Firms often use EAC for capital budgeting decisions, as it allows a company to compare the cost-effectiveness of various assets with unequal lifespans.
How to calculate EAC?
Next, we calculate the EAC, which is equal to the net present value (NPV) divided by the present value annuity factor or A (t,r), while taking into account the cost of capital or r, and the number of years in question or t.
What is EAC calculation?
The EAC calculation factors in a discount rate or the cost of capital. Cost of capital is the required return necessary to make a capital budgeting project—such as building a new factory—worthwhile. Cost of capital includes the cost of debt and the cost of equity and is used by companies internally to judge whether a capital project is worth the expenditure of resources.
Why do firms use EAC?
Firms often use EAC for capital budgeting decisions, as it allows a company to compare the cost-effectiveness of various assets with unequal lifespans. 0:46.
What is EAC used for?
Other uses of EAC include calculating the optimal life of an asset, determining if leasing or purchasing an asset is the better option, determining the magnitude of which maintenance costs will impact an asset, determining the necessary cost savings to support purchasing a new asset, and determining the cost of keeping existing equipment.
What is the difference between EAC and whole life cost?
The equivalent annual cost (EAC) is the annual cost of owning, operating, and maintaining an asset over its entire life while the whole life cost is the total cost of the asset over its entire life.
What is EAC in capital budgeting?
Equivalent annual cost (EAC) is used for a variety of purposes, including capital budgeting. But it is used most often to analyze two or more possible projects with different lifespans, where costs are the most relevant variable.
Overview
Applications
Risk assessment is the process by which one estimates the probability of some adverse effect, such as that of a contaminant in the environment. Environmental risk assessments are conducted to help protect human health and the environment and are often used to assist in meeting regulations such as those stipulated by CERCLA in the United States. Risk assessments may take place retroactively, i.e., when assessing the contamination hazard at a superfund site, or predicti…
Chemical mixtures and additivity
Humans and wildlife are rarely exposed to solitary contaminants, but rather to complex mixtures of potentially harmful compounds. Dioxins and DLCs are no exception. This is important to consider when assessing toxicity because the effects of chemicals in a mixture are often different from when acting alone. These differences can take place on the chemical level, where the properties of the compounds themselves change due to the interaction, creating a new dose at t…
TEF
Exposure to environmental media containing 2,3,7,8-TCDD and other dioxins and dioxin-like compounds can be harmful to humans as well as to wildlife. These chemicals are resistant to metabolism and biomagnify up the food chain. Toxic and biological effects of these compounds are mediated through the aryl hydrocarbon receptor (AhR). Oftentimes results of human activity leads to instances of these chemicals as mixtures of DLCs in the environment. The TEF approac…
TEQ
Toxic Equivalents (TEQs) report the toxicity-weighted masses of mixtures of PCDDs, PCDFs, and PCBs. The reported value provides toxicity information about the mixture of chemicals and is more meaningful to toxicologists than reporting the total number of grams. To obtain TEQs the mass of each chemical in a mixture is multiplied by its TEF and is then summed with all other chemicals to report the total toxicity-weighted mass. TEQs are then used for risk characterizatio…
History and development
Dating back to the 1980s there is a long history of developing TEFs and how to use them. New research being conducted influences guiding criteria for assigning TEFs as the science progresses. The World Health Organization has held expert panels to reach a global consensus on how to assign TEFs in conjunction with new data. Each individual country recommends their own TEF values, typically endorsing the WHO global consensus TEFs.
Other compounds for potential inclusion
Based on mechanistic considerations, PCB 37, PBDDs, PBDFs, PXCDDs, PXCDFs, PCNs, PBNs and PBBs can be included in the TEF concept. However, most of these compounds lack human exposure data. Thus, TEF values for these compounds are in the process of review
See also
• Dioxins and dioxin-like compounds