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Using if Statements to Make Decisions
You use an if statement when you want to choose between executing two different blocks
of code depending on the result of a Boolean expression.
Understanding if Statement Syntax
The syntax of an if statement is as follows (if and else are keywords):
if ( booleanExpression )
statement-1;
else
statement-2;
If booleanExpression evaluates to true, then statement-1 runs; otherwise
booleanExpression is false, and statement-2 runs. The else keyword and the following
statement-2 are optional. If there is no else clause, nothing happens when the
booleanExpression is false.
For example, here's an if statement that increments the seconds hand of a stopwatch
(minutes are ignored for now). If the value of the seconds variable is 59, it is reset to 0,
otherwise it is incremented using the ++ operator:
int seconds;
if (seconds == 59)
seconds = 0;
else
seconds++;
Boolean Expressions Only Please!
The expression in an if statement must be enclosed in parentheses. Additionally, the
expression must be a Boolean expression. In some other languages (notably C and C++),
you can write an integer expression, and the compiler will silently convert the integer
value to true (nonzero) or false (zero). C# does not support this behavior, and the
compiler reports an error if you write such an expression.
If you accidentally write an assignment instead of an equality test in an if statement, the
C# compiler recognizes your mistake. For example:
int seconds;
if (seconds = 59) // compile-time error
if (seconds == 59) // ok
Accidental assignments were another common source of bugs in C and C++ programs,
which would silently convert the value assigned (59) into a Boolean expression (anything
non-zero was considered to be true), with the result that the code following the if
statement would be performed every time.
Finally, you can use a Boolean variable as the expression, as in this example:
bool inWord;
if (inWord == true) // ok, but not commonly used
if (inWord) // better
Using Blocks to Group Statements
Sometimes you'll want to run two or more statements when a Boolean expression is true.
You could group the statements inside a new method and then call the new method, but a
simpler solution is to group the statements inside a block. A block is simply a sequence
of statements grouped between an opening and a closing curly brace. In the following
example, two statements that reset the seconds variable to zero and increment the minutes
variable are grouped inside a block, and the whole block executes if the value of seconds
is equal to 59:
int seconds = 0;
int minutes = 0;
if (seconds == 59)
{
seconds = 0;
minutes++;
}
else
seconds++;
IMPORTANT
If you omit the curly braces, the C# compiler associates only the first statement (seconds
= 0) with the if statement. The subsequent statement (minutes++) will not be recognized
by the compiler as part of the if statement when the program is compiled. Furthermore,
when the compiler reaches the else keyword, it will not associate it with the previous if
statement, so it reports a syntax error instead.
Cascading if Statements
You can nest if statements inside other if statements. In this way, you can chain together
a sequence of Boolean expressions, which are tested one after the other until one of them
evaluates to true. In the following example, if the value of day is 0, the first test evaluates
to true and dayName is assigned Sunday. If the value of day is not 0, the first test fails
and control passes to the else clause, which runs the second if statement and Using Light Energy to Make Organic Molecules Using Light Energy to Make Organic Molecules Bởi: OpenStaxCollege After the energy from the sun is converted into chemical energy and temporarily stored in ATP and NADPH molecules, the cell has the fuel needed to build carbohydrate molecules for long-term energy storage The products of the light-dependent reactions, ATP and NADPH, have lifespans in the range of millionths of seconds, whereas the products of the light-independent reactions (carbohydrates and other forms of reduced carbon) can survive for hundreds of millions of years The carbohydrate molecules made will have a backbone of carbon atoms Where does the carbon come from? It comes from carbon dioxide, the gas that is a waste product of respiration in microbes, fungi, plants, and animals The Calvin Cycle In plants, carbon dioxide (CO2) enters the leaves through stomata, where it diffuses over short distances through intercellular spaces until it reaches the mesophyll cells Once in the mesophyll cells, CO2 diffuses into the stroma of the chloroplast—the site of light-independent reactions of photosynthesis These reactions actually have several names associated with them Another term, the Calvin cycle, is named for the man who discovered it, and because these reactions function as a cycle Others call it the CalvinBenson cycle to include the name of another scientist involved in its discovery The most outdated name is dark reactions, because light is not directly required ([link]) However, the term dark reaction can be misleading because it implies incorrectly that the reaction only occurs at night or is independent of light, which is why most scientists and instructors no longer use it 1/8 Using Light Energy to Make Organic Molecules Light reactions harness energy from the sun to produce chemical bonds, ATP, and NADPH These energy-carrying molecules are made in the stroma where carbon fixation takes place The light-independent reactions of the Calvin cycle can be organized into three basic stages: fixation, reduction, and regeneration Stage 1: Fixation In the stroma, in addition to CO2, two other components are present to initiate the lightindependent reactions: an enzyme called ribulose bisphosphate carboxylase (RuBisCO), and three molecules of ribulose bisphosphate (RuBP), as shown in [link] RuBP has five atoms of carbon, flanked by two phosphates Art Connection 2/8 Using Light Energy to Make Organic Molecules The Calvin cycle has three stages In stage 1, the enzyme RuBisCO incorporates carbon dioxide into an organic molecule, 3-PGA In stage 2, the organic molecule is reduced using electrons supplied by NADPH In stage 3, RuBP, the molecule that starts the cycle, is regenerated so that the cycle can continue Only one carbon dioxide molecule is incorporated at a time, so the cycle must be completed three times to produce a single three-carbon GA3P molecule, and six times to produce a six-carbon glucose molecule Which of the following statements is true? In photosynthesis, oxygen, carbon dioxide, ATP, and NADPH are reactants GA3P and water are products In photosynthesis, chlorophyll, water, and carbon dioxide are reactants GA3P and oxygen are products In photosynthesis, water, carbon dioxide, ATP, and NADPH are reactants RuBP and oxygen are products In photosynthesis, water and carbon dioxide are reactants GA3P and oxygen are products RuBisCO catalyzes a reaction between CO2 and RuBP For each CO2 molecule that reacts with one RuBP, two molecules of another compound (3-PGA) form PGA has three carbons and one phosphate Each turn of the cycle involves only one RuBP and one carbon dioxide and forms two molecules of 3-PGA The number of carbon atoms remains the same, as the atoms move to form new bonds during the reactions (3 atoms from 3CO2 + 15 atoms from 3RuBP = 18 atoms in atoms of 3-PGA) This process is called carbon fixation, because CO2 is “fixed” from an inorganic form into organic molecules 3/8 Using Light Energy to Make Organic Molecules Stage 2: Reduction ATP and NADPH are used to convert the six molecules of 3-PGA into six molecules of a chemical called glyceraldehyde 3-phosphate (G3P) That is a reduction reaction because it involves the gain of electrons by 3-PGA Recall that a reduction is the gain of an electron by an atom or molecule Six molecules of both ATP and NADPH are used For ATP, energy is released with the loss of the terminal phosphate atom, converting it into ADP; for NADPH, both energy and a hydrogen atom are lost, converting it into NADP+ Both of these molecules return to the nearby light-dependent reactions to be reused and reenergized Stage 3: Regeneration Interestingly, at this point, only one of the G3P molecules leaves the Calvin cycle and is sent to the cytoplasm to contribute to the formation of other compounds needed by the plant Because the G3P exported from the chloroplast has three carbon atoms, it takes three “turns” of the Calvin cycle to fix enough net carbon to export ...[...]... information 16 In the know | Information, information, information: relevance, quality and presentation In the know | Information, information, information: relevance, quality and presentation 17 should apply these principles when considering the information that they need, how they can ensure it is available to them, and whether they have the right information presented in a way they can interpret easily This... good judgement about what to use and how, but also creates opportunities to make good use of information across whole areas 26 In the know | Information, information, information: relevance, quality and presentation Information quality depends on data quality 54 Information is derived by combining data in ways which create meaning, often alongside contextual information Good quality information depends... politicians make assessments of the views of their electors every day, and these may be the best available information on what electors want or would accept But politicians also have to weigh up competing priorities, and they rely on relevant, objective information to help them understand the consequences of the trade-offs inherent in the decisions that they have to take In the know | Information, information, ... Example 3 highlights some of the existing good practice in the use of information at different geographic levels Example 3 Managing and using geographic information Manchester Salford Partnership Housing Market Renewal Pathfinder has in place a suite of analytical tools to monitor and understand housing markets at different geographical levels The tracking Neighbourhood Change Model plots indicators... have indicated an alarm in the Shipman and Bristol Royal Infirmary cases (Ref 20) The research looked at adverse clinical outcomes for patients aged 65 years and over under the care of Harold Shipman between 1979 and 1997, and patients under one year of age undergoing paediatric heart surgery in Bristol Royal Infirmary between 1984 and 1995 The research showed that monitoring annual and 30-day mortality... considerations to bear in mind include: the level of aggregation (whether that is over geography, time or by type of information) ; using a range of information to provide a fuller picture; not relying exclusively on performance indicators; and sharing information within and between public and other bodies Aggregating information to make it relevant 36 Some decisions rely on local information, whereas others... time period they require information The opportunity for using trends to generate relevant and important insights was exposed in the cases of both Dr Harold Shipman and Bristol Royal Infirmary, as shown by Example 4 20 In the know | Information, information, information: relevance, quality and presentation Example 4 Shipman and Bristol Royal Infirmary Research has identified that using longer-term trends... styles, and the amount of time they have to consider the information Otherwise important information will be ignored or misunderstood, or inconvenient information may cause an unhelpful In the know | Information, information, information: relevance, quality and presentation 31 reaction
June 20, 2011
Using Qualified Energy Conservation Bonds (QECBs)
to Fund a Residential Energy Efficiency Loan Program:
Case Study on Saint Louis County, MO
Qualified Energy Conservation Bonds (QECBs) are federally-subsidized debt instruments that enable
state, tribal, and local government issuers to borrow money to fund a range of qualified energy
conservation projects. QECBs offer issuers very attractive borrowing rates and long terms, and can
fund low-interest energy efficiency loans for home and commercial property owners. Saint Louis
County, MO recently issued over $10 million of QECBs to finance the Saint Louis County SAVES
residential energy efficiency loan program. The county’s experience negotiating QECB regulations and
restrictions can inform future issuers.
QECB Background
A Qualified Energy Conservation Bond (QECB) is a debt instrument that enables qualified state, tribal
and local government issuers to borrow money to fund qualified energy conservation projects.
1
First
established by the Energy Improvement and Extension Act of 2008, QECB issuance capacity was
expanded from $800 million to $3.2 billion by the American Recovery and Reinvestment Act of 2009.
The Department of Energy estimates that between 10 and 15 percent of this issuance capacity has been
used. A QECB is among the lowest-cost public financing tools because the U.S. Department of
Treasury subsidizes the issuer's borrowing costs. Issuers may choose between structuring QECBs as
tax credit bonds (bond investors receive federal tax credits in lieu of—or in addition to—interest
payments) or as direct subsidy bonds (bond issuers receive cash rebates from the Treasury to subsidize
their interest payments). Both tax credit and direct payment bonds subsidize borrowing costs, but most
QECBs are being issued as direct subsidy bonds due to lack of investor appetite for tax credit bonds.
1
For a full list of eligible projects, visit http://www1.eere.energy.gov/wip/solutioncenter/financialproducts/QECB.html
ThisispartofanongoingseriesofCleanEnergyFinancingPolicyBriefsproducedbyLBNL.Usingcasestudies,these
workingpaperswillhighlightemergingfinancingprogrammodels,importantissuesthatnewprogramsface,andhow
theseissuesarebeingaddressed.TheworkdescribedinthisPolicyBriefwasfunded
bytheDepartmentofEnergyOffice
ofEnergyEfficiencyandRenewableEnergy,WeatherizationandIntergovernmentalProgramunderContractNo.DE
AC02‐05CH11231.PleasedirectquestionsorcommentstoMarkZimring(mzimring@lbl.gov
).
QECB Applications: Green Communities Programs
The Federal legislation that established QECBs listed several ‘qualified’ uses of bond proceeds
including energy upgrades to public buildings, mass transit projects, and green community programs.
The term ‘green community program’ is undefined in Federal statute, but the controlling legislative
history in the Conference Report to the American Recovery and Reinvestment Act provides clear
guidance that loan programs for energy upgrades on private buildings do qualify as green community
programs. The Conference Report includes the following statement regarding Congressional intent
about the broad intended scope of this term:
Also, the provision clarifies that capital expenditures to implement green community programs
includes grants, loans, and other [...]... traffic” to a brick -and- mortar store or web traffic to an e-commerce store Google and the other “Pay Per Click” advertising systems—can help you generate that traffic We’ve split this book into three main parts In Part I, you’ll learn how to begin working through eBay, selling your wares through auctions, Buy It Now sales, and the eBay store In Part II, you’ll find out how to set up a Web store using Yahoo!’s... 241 Configuring Shipping, Taxes, and Inventory 243 Specifying Where You Ship—Foreign Orders 243 xv xvi How to Make Money Online with eBay, Yahoo!, and Google CHAPTER 20 Setting Up Shipping Methods and Rates Using UPS OnLineTM Tools Creating Shipping Methods Defining Shipping Rates and Creating Rules ... Shipping, Taxes, and Inventory Processing Orders Promotion Strategies and Tools 139 153 173 189 205 217 231 243 261 273 ix x How to Make Money Online with eBay, Yahoo!, and Google Using Google Pay Per Click and More to Grow Traffic PART III 22 23 24 25 26 27 28 29 Google AdWords and Other Pay Per Click... another Using multiple channels to sell and to reach people increases the likelihood that you find the best one Copyright © 2006 by The McGraw-Hill Companies Click here for terms of use 4 How to Make Money Online with eBay, Yahoo!, and Google ■ Multiple channels provide multiple opportunities If you can find people to buy your products more than one way, why leave money on the table by only using one... ThinkGeek.com, which sells tons of really cool stuff (Figure 1-1) Another example of a great word-of-mouth site is Despair.com This company sells products that people put on their office walls and laugh about with their friends 5 6 How to Make Money Online with eBay, Yahoo!, and Google FIGURE 1-1 ThinkGeek.com is a classic word-of-mouth site—people love it and tell their friends ■ No need to touch, smell, or... 146 xiii xiv How to Make Money Online with eBay, Yahoo!, and Google CHAPTER 13 CHAPTER 14 CHAPTER 15 CHAPTER 16 Picking a Domain Name Registering for a Yahoo! Merchant Solutions Account Pointing Your Domain to Your Store Pointing www to the Store Finding Your Way Around the Store Manager... patience and a willingness to go through the steps to get it right, though That’s what we’re going to teach you here Why Three Services? In this book we explain how to use three different “channels” to build your business online: ■ Selling products through eBay auctions ■ Chapter Photosynthesis: Using Light to Make Food PowerPoint Lectures for Campbell Biology: Concepts & Connections, Seventh Edition Reece, Taylor, Simon, and Dickey © 2012 Pearson Education, Inc Lecture by Edward J Zalisko Introduction Plants, algae, and certain prokaryotes – convert light energy to chemical energy and – store the chemical energy in sugar, made from – carbon dioxide and – water © 2012 Pearson Education, Inc Introduction Algae farms can be used to produce – oils for biodiesel or – carbohydrates to generate ethanol © 2012 Pearson Education, Inc Figure 7.0_1 Chapter 7: Big Ideas An Overview of Photosynthesis The Calvin Cycle: Reducing CO2 to Sugar The Light Reactions: Converting Solar Energy to Chemical Energy Photosynthesis Reviewed and Extended AN OVERVIEW OF PHOTOSYNTHESIS © 2012 Pearson Education, Inc 7.1 Autotrophs are the producers of the biosphere Autotrophs – make their own food through the process of photosynthesis, – sustain themselves, and – not usually consume organic molecules derived from other organisms © 2012 Pearson Education, Inc 7.1 Autotrophs are the producers of the biosphere Photoautotrophs use the energy of light to produce organic molecules Chemoautotrophs are prokaryotes that use inorganic chemicals as their energy source Heterotrophs are consumers that feed on – plants or – animals, or – decompose organic material © 2012 Pearson Education, Inc 7.1 Autotrophs are the producers of the biosphere Photosynthesis in plants – takes place in chloroplasts, – converts carbon dioxide and water into organic molecules, and – releases oxygen © 2012 Pearson Education, Inc Figure 7.1A-D 7.2 Photosynthesis occurs in chloroplasts in plant cells Chloroplasts are the major sites of photosynthesis in green plants Chlorophyll – is an important light-absorbing pigment in chloroplasts, – is responsible for the green color of plants, and – plays a central role in converting solar energy to chemical energy © 2012 Pearson Education, Inc 7.10 ATP and NADPH power sugar synthesis in the Calvin cycle The Calvin cycle makes sugar within a chloroplast To produce sugar, the necessary ingredients are – atmospheric CO2 and – ATP and NADPH generated by the light reactions The Calvin cycle uses these three ingredients to produce an energy-rich, three-carbon sugar called glyceraldehyde-3-phosphate (G3P) A plant cell may then use G3P to make glucose and other organic molecules © 2012 Pearson Education, Inc Figure 7.10A Input CO2 ATP NADPH Calvin Cycle Output: G3P 7.10 ATP and NADPH power sugar synthesis in the Calvin cycle The steps of the Calvin cycle include – carbon fixation, – reduction, – release of G3P, and – regeneration of the starting molecule ribulose bisphosphate (RuBP) © 2012 Pearson Education, Inc Figure 7.10B_s1 Step Carbon fixation Input: CO2 Rubisco P P RuBP 3-PGA Calvin Cycle P Figure 7.10B_s2 Step Carbon fixation Input: CO2 Rubisco P Step Reduction P RuBP 3-PGA P ATP ADP Calvin Cycle NADPH P G3P NADP+ P Figure 7.10B_s3 Step Carbon fixation Input: CO2 Rubisco P Step P RuBP Reduction 3-PGA P ATP ADP Calvin Cycle Step Release of one molecule of G3P G3P NADPH P P NADP+ G3P Output: P G3P Glucose and other compounds P Figure 7.10B_s4 Step Carbon fixation Input: CO2 Rubisco P Step P RuBP Reduction 3-PGA P ADP Calvin Cycle G3P Step Regeneration of RuBP ATP ADP ATP Step Release of one molecule of G3P 6 NADPH P P NADP+ G3P Output: P G3P Glucose and other compounds P 7.11 EVOLUTION CONNECTION: Other methods of carbon fixation have evolved in hot, dry climates Most plants use CO2 directly from the air, and carbon fixation occurs when the enzyme rubisco adds CO2 to RuBP Such plants are called C3 plants because the first product of carbon fixation is a three-carbon compound, 3-PGA © 2012 Pearson Education, Inc 7.11 EVOLUTION CONNECTION: Other methods of carbon fixation have evolved in hot, dry climates In hot and dry weather, C3 plants – close their stomata to reduce water loss ... from an inorganic form into organic molecules 3/8 Using Light Energy to Make Organic Molecules Stage 2: Reduction ATP and NADPH are used to convert the six molecules of 3-PGA into six molecules. .. this photosynthesis remain largely the same Photosystems absorb light and use electron transport chains to convert 4/8 Using Light Energy to Make Organic Molecules energy into the chemical energy. . .Using Light Energy to Make Organic Molecules Light reactions harness energy from the sun to produce chemical bonds, ATP, and NADPH These energy- carrying molecules are made
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