Unit VIII Problem Solving Worksheet

/0 Comments/in /by

Unit VIII Problem Solving Worksheet

This assignment will allow you to demonstrate the following objectives:

Describe thermodynamic concepts and their applications.

Extend the first law of thermodynamics to various daily life activities.

Identify the maximum efficiency of a heat engine.

Explain the role of latent heat while phases are changing.

Instructions: Choose 8 of the 10 problems below. Show your work in detail. Answer the questions directly in this template. Before doing this, it is highly recommending that you thoroughly review the four examples in the Unit Lesson.

The efficiency of a Carnot engine is e=1-Tc/TH, where Tc is a temperature of the cold reservoir and TH is a temperature of the hot reservoir. What is the condition to have 100% efficiency? Hint: What is the mathematical condition for Tc/TH to be zero.

Suppose the work done to compress a gas is 100 J. If 70 J of heat is lost in the process, what is the change in the internal energy of the gas? Hint: Use the first law of thermodynamics. The internal energy of a system changes due to heat (Q) and work (W): U=Q-W. The change in internal energy is equivalent to the difference between the heat added to the system and the work done by the system. Think if the work done is to the system or by the system. This determines the sign of W.

An engine’s fuel is heated to 2,000 K and the surrounding air is 300 K. Calculate the ideal efficiency of the engine. Hint: The efficiency (e) of a Carnot engine is defined as the ratio of the work (W) done by the engine to the input heat QH : e=W/QH. W=QH – QC, where Qc is the output heat. That is, e=1-Qc/QH =1-Tc/TH, where Tc for a temperature of the cold reservoir and TH for a temperature of the hot reservoir. The unit of temperature must be in Kelvin.

Mr. White claims that he invented a heat engine with a maximum efficiency of 90%. He measured the temperature of the hot reservoir as 100o C and that of cold reservoir as 10o C. Find the error that he made and calculate the correct efficiency. Hint: The efficiency (e) of a Carnot engine is defined as the ratio of the work (W) done by the engine to the input heat QH : e=W/QH. W=QH – QC, where Qc is the output heat. That is, e=1-Qc/QH =1-Tc/TH, where Tc for a temperature of the cold reservoir and TH for a temperature of the hot reservoir. The unit of temperature must be in Kelvin.

How much energy is needed to change 100 g of 0o C ice to 0o C water? The latent heat of fusion for water L=335,000 J/kg. Hint: The heat (Q) used to change from one phase to another phase of the matter is Q=mL, where L is the latent heat. Its unit is J/kg.

It was determined in the 19th century that the normal human body temperature is 98.6o F. A more recent study found that it is 98.2o F. Express the difference in the temperature in Celsius. Hint: Use the converting formula between Fahrenheit and Celsius scales: F=9/5C +32. Be careful about the unit.

Suppose 0.5 kg of blood flows from the interior to the surface of John’s body while he is exercising. The released energy is 2,000 J. The specific heat capacity of blood is 4,186 J/kgo C. What is the temperature difference between when the blood arrives at the body surface and returns back to the interior of the body? Hint: Use the formula regarding heat Q, specific heat capacity c, mass m, and temperature change dT. Q= cm dT. Please look at p.290 in our textbook. Also, review Example 1 with its solution in Study Guide.

A student does 1,000 J of work when she moves to her dormitory. Her internal energy is decreased by 3,000 J. Determine the heat during this process. Does she gain or lose her heat? Hint: Use the first law of thermodynamics. The internal energy of a system changes due to heat Q and work done W: U=Q-W. Also, look at a similar case, Example 3 with its solution in Study Guide.

In a construction site, 2 kg of aluminum shows the increment of temperature by 5oC. Ignoring the work, what is the change in the internal energy of the material? The specific heat capacity of aluminum is 900 J/kg oC. Hint: The internal energy of a system changes due to heat Q and work done W: U=Q-W. If we ignore, the work, the internal energy U is identical to the heat Q of the system. We know that relation between heat Q, specific heat capacity c, mass m, and temperature change dT; Q= cm dT. That is, U=Q=cm dT.

The input heat of a Carnot engine is 3,000 J. The temperature of a hot reservoir is 600 K and that of a cold reservoir is 300 K. What is the work done? Hint: The efficiency e of a Carnot engine is defined as the ratio of the work done, W, by the engine to the input heat QH : e=W/QH. W=QH – QC, where Qc is the output heat. That is, e=1-Qc/QH =1-Tc/TH, where Tc for a temperature of the cold reservoir and TH for a temperature of the hot reservoir. The unit of temperature must be in Kelvin.

Use the formula, e=1-Tc/TH. Please review the Example 4 with its solution in Study Guide. Once you evaluate, you can find the work done of the system using the formula, e=W/QH

IHP 330 Module Two Worksheet Measuring Disease

/0 Comments/in /by

IHP 330 Module Two Worksheet Measuring Disease

A causal relationship between cigarette smoking and lung cancer was first suspected in the 1920s on the basis of clinical observations. To test this apparent association, numerous epidemiologic studies were undertaken between 1930 and 1960. Two studies were conducted by Richard Doll and Austin Bradford Hill in Great Britain. The first was a case-control study begun in 1947 comparing the smoking habits of lung cancer patients with the smoking habits of other patients. The second was a cohort study begun in 1951 recording causes of death among British physicians in relation to smoking habits. This case study deals first with the case-control study, then with the cohort study.

Data for the case-control study were obtained from hospitalized patients in London and vicinity over a four-year period (April 1948 – February 1952). Initially, 20 hospitals, and later more, were asked to notify the investigators of all patients admitted with a new diagnosis of lung cancer. These patients were then interviewed concerning smoking habits, as were controls selected from patients with other disorders (primarily nonmalignant) who were hospitalized in the same hospitals at the same time. Data for the cohort study were obtained from the population of all physicians listed in the British Medical Register who resided in England and Wales as of October 1951. Information about present and past smoking habits was obtained by questionnaire. Information about lung cancer came from death certificates and other mortality data recorded during ensuing years.

Over 1700 patients with lung cancer, all under age 75 were eligible for the case-control study. About 15% of these persons were not interviewed because of death, discharge, severity of illness, or inability to speak English. An additional group of patients were interviewed by later excluded when initial lung cancer diagnosed proved mistaken. The final study group included 1,465 cases (1,357 males and 108 females). The following table shows the relationship between cigarette smoking and lung cancer among male cases and controls:

Table 1

Cases Controls
Cigarette Smoker 1,350 1,296
Nonsmoker 7 61
Total 1,357 1,357

1. Accurately calculate the proportion of cases that smoked. Be sure to show your calculations.

2. Accurately calculate the proportion of controls that smoked. Be sure to show your calculations.

3. Accurately calculate the odds ratio, with the correct equation. What do you infer from the odds ratio about the relationship between smoking and lung cancer?

Table 2 shows the frequency distribution of male cases and controls by average number of cigarettes smoked per day.

Table 2: Daily cigarette consumption

Daily Number of Cigarettes Number of Cases Number of Controls Odds Ratio
0 7 61 Referent
1–14 565 706
15–24 445 408
25+ 340 182
All smokers 1350 1296
Total 1357 1357

4. Accurately calculate the odds ratios by category of daily cigarette consumption, comparing each category to nonsmokers. Be sure to show your calculations.

5. Interpret these results, and describe the trends or patterns you see in the data.

Part 2: The Cohort Study

Data for the cohort study were obtained from the population of all physicians listed in the British Medical Register who resided in England and Wales as of October 1951. Questionnaires were mailed in October 1951 to 59,600 physicians. The questionnaire asked the physicians to classify themselves into one of three categories: 1) current smoker, 2) ex-smoker, or 3) nonsmoker. Smokers and ex-smokers were asked the amount they smoked, their method of smoking, the age they started to smoke, and, if they had stopped smoking, how long it had been since they last smoked. Nonsmokers were defined as persons who had never consistently smoked as much as one cigarette day for as long as one year. Physicians were also asked whether or not they had a diagnosis of lung cancer. Usable responses to the questionnaires were received from 40,637 (68%) physicians, of whom 34,445 were males and 6,192 were females. The next section of this case study is limited to the analysis of male physician respondents, 35 years of age or older.

The occurrence of lung cancer in physicians responding to the questionnaire was documented over a 10-year period (November 1951 through October 1961) from death certificates filed with the Registrar General of the United Kingdom and from lists of physician deaths provided by the British Medical Association. All certificates indicating that the decedent was a physician were abstracted. For each death attributed to lung cancer, medical records were reviewed to confirm the diagnosis.

Diagnoses of lung cancer were based on the best evidence available; about 70% were from biopsy, autopsy, or sputum cytology (combined with bronchoscopy or X-ray evidence); 29% were from cytology, bronchoscopy, or X-ray alone; and only 1% were from just case history, physical examination, or death certificate. In total, there were 355 cases of lung cancer during this 10-year time period, with 255 newly diagnosed cases of lung cancer.

Of 4,597 deaths in the cohort over the 10-year period, 157 were reported to have been caused by lung cancer; in 4 of the 157 cases this diagnosis could not be documented, leaving 153 confirmed deaths from lung cancer.

The following table shows numbers of lung cancer deaths by daily number of cigarettes smoked at the time of the 1951 questionnaire (for male physicians who were nonsmokers and current smokers only). Person-years of observation (“person-years at risk”) are given for each smoking category. The number of cigarettes smoked was available for 136 of the persons who died from lung cancer.

Table 3: Number and rate (per 100,000 person-years) of lung cancer deaths by number of cigarettes smoked per day, Doll and Hill physician cohort study, Great Britain, 1951–1961.

Daily number of cigarettes smoked Deaths from lung cancer Person-years at risk Mortality rate per 1,000 person-years
0 3 42,800 0.07
1–14 22 38,600
15–24 54 38,900
25+ 57 25,100
All smokers 133 102,600
Total 136 145,400

6. Accurately calculates the lung cancer mortality rates for each smoking category. Be sure to show your calculations.

7. Describe the trends or patterns you see in the data about mortality, and explain what the trends or patterns mean.

8. Accurately calculate the incidence for lung cancer during the 10 year time period. Be sure to show your calculations.

9. Accurately calculate the prevalence for lung cancer during this 10 year time period. Be sure to show your calculations.

Explain intersectionality

/0 Comments/in /by
  1. Explain intersectionality
  2. Explain at least one social philosophy from the textbook. For instance, you might discuss utilitarianism, Rawls, Marx, Nozick, Du Bois, King, or Beauvoir. If the theory has a clear correlate, please discuss it as well.
  3. Illustrate your understanding of both the intersectional and traditional social justice approaches with examples.
  4. Support your account of the theories with citations to the textbook and online lectures in correct APA format. Use this APA Citation Helper as a convenient reference for properly citing resources.

Decision making is a function relegated to department officers of rank who are empowered with the authority to make decisions that affect many other emergency response personnel

/0 Comments/in /by

Question 1

Decision making is a function relegated to department officers of rank who are empowered with the authority to make decisions that affect many other emergency response personnel. Discuss the concepts and importance of CRM and The 2&7 Tool as both are applied to the fire service. Include details of each element of both managerial decision making applications.

Your response should be at least 200 words in length. You are required to use at least your textbook as source material for your response. All sources used, including the textbook, must be referenced; paraphrased and quoted material must have accompanying citations.

19 points

Question 2

Hazardous material incidents require keen observation and a cautious approach, as many hazardous materials may not be properly identified or known to emergency responders. Incident management is critical in order to reduce injury and loss of life. Discuss the appropriate methodology for approaching a hazardous material incident. Include details of managerial responsibility and personnel safety, including proper protective clothing.

Your response should be at least 200 words in length. You are required to use at least your textbook as source material for your response. All sources used, including the textbook, must be referenced; paraphrased and quoted material must have accompanying citations.

8.1 Examining the Hydrologic Cycle

/0 Comments/in /by

8.1 Examining the Hydrologic Cycle

1. Sketch, label, and discuss the hydrologic cycle.

Earth’s water is constantly moving between Earth’s surface and atmosphere. The hydrologic cycle describes the continuous movement of water from the oceans to the atmosphere, from the atmosphere to the land, and from the land back to the sea. Over most of Earth, the quantity of precipitation that falls on the land must eventually be accounted for by the sum total of evaporation, transpiration (the release of water vapor by vegetation), runoff, and infiltration.

A portion of the precipitation that falls on land will soak into the ground through a process called infiltration. If the rate of rainfall exceeds the ability of the surface to absorb it, the additional water flows over the surface and becomes runoff. Runoff initially flows in broad sheets that form tiny channels called rills. The rills merge to form gullies, which eventually join to create streams. Erosion by both groundwater and running water wears down the land and shapes Earth’s surface.

Figure 8.1 illustrates Earth’s water balance, a quantitative view of the hydrologic cycle. The figure implies a globally uniform exchange of water between Earth’s atmosphere and surface, but factors such as climate, steepness of slope, surface materials, vegetation, and degree of urbanization produce local variations.

SmartFigure 8.1 Earth’s water balance, a quantitative view of the hydrologic cycle.

Watch

SmartFigure: The Water Cycle

Activity 8.1: Examining the Hydrologic Cycle

Use Figure 8.1 as a reference to complete the following:

1. Globally, from which source does more water evaporate into the atmosphere: oceans or land?

 

2. Approximately what percentage of the total water evaporated into the atmosphere comes from the oceans?

Percentage from oceans=Ocean evaporationTotal evaporation×100%=−−−−−−−−−−−−− %Percentage from oceans=Ocean evaporationTotal evaporation×100%=_ %

3. Notice in Figure 8.1 that more water evaporates from the oceans than is returned directly by precipitation. If sea level is not dropping, identify a source of water for the oceans in addition to precipitation.

 

4. Worldwide, about how much of the precipitation that falls on the land becomes runoff: 35, 55, or 75 percent?

About                                    % becomes runoff.

5. Much of the water that falls on land does not immediately return to the ocean via runoff. Instead, it is temporarily stored in reservoirs such as lakes. In some mountainous and polar regions, what features serve as reservoirs to temporarily store water?

 

6. Label the drawing in Figure 8.2 with the letters that correspond to the following terms:

Figure 8.2Illustration (cross section) of the hydrologic cycle.

9.3 Glaciers and Ice Sheets

1. Contrast alpine (valley) glaciers and ice sheets.

Present-day glaciers cover nearly 10 percent of Earth’s land area. At the height of the Quaternary Ice Age, glaciers were three times more extensive than they are today. These moving masses of ice create many unique landforms and are part of an important link in the rock cycle in which the products of weathering are transported and deposited as sediment.

A glacier is a thick ice mass that, over hundreds or thousands of years, forms on land as the yearly snowfall exceeds the quantity of ice lost by melting. A glacier appears to be motionless, but it is not; glaciers move very slowly. Thousands of glaciers exist in lofty mountain areas, where they usually follow valleys originally occupied by streams. Because of their settings, these moving ice masses are termed valley glaciers, or alpine glaciers.

Ice sheets (sometimes called continental glaciers) exist on a much larger scale than valley glaciers. These enormous masses flow out in all directions from one or more snow-accumulation centers and completely obscure all but the highest areas of underlying terrain. Presently each of Earth’s polar regions supports an ice sheet—Greenland in the Northern Hemisphere and Antarctica in the Southern Hemisphere.

Glacial erosion and deposition leave unmistakable imprints on Earth’s surface (Figure 9.5). In regions once covered by ice sheets, glacially scoured surfaces and subdued terrain dominate. By contrast, erosion caused by alpine glaciers accentuates the irregular mountainous topography, often producing spectacular scenery characterized by sharp, angular features. Glacial deposits are usually visible in both settings.

Figure 9.5Moving glacial ice, armed with sediment, acts like sandpaper, scratching and polishing rock and creating glacial striations.

(Photo by Michael Collier)

Activity 9.3: Glaciers and Ice Sheets

1. What percentage of Earth’s land surface do glaciers presently cover?

%

2. Identify two locations where ice sheets are currently found.

 

3. Briefly compare an ice sheet to a valley glacier.

 

Activity 9.6B: Identifying Glacial Features on a Topographic Map

Refer to Figure 9.13, a portion of the Holy Cross, Colorado, topographic map. This is a mountainous area that has been shaped by alpine glaciers.

Figure 9.13Holy Cross, Colorado

(Courtesy of U.S. Geological Survey)

1. Identify the glacial feature indicated by each of the following letters. Use Figure 9.12C as a reference.

· Letter A:

· Letter B:

2. A tarn is a lake that forms in a cirque. Of the features labeled C, D, E, and F, which indicate(s) a tarn(s)?

Letter(s):

3. The feature marked G on the map is a depositional feature composed of glacial till. What type of glacial feature is it? How did it form?

 

 

4. Explain how Turquoise Lake likely formed.

 

 

5. Use Figure 9.14 to draw a topographic profile along the X–Y line from Sugar Loaf Mountain to Bear Lake and mark the position of the Lake Fork stream. (Use only index contours.)

Figure 9.14Topographic profile of the valley of Lake Fork on the Holy Cross, Colorado, map.

6. Describe the shape of Lake Fork Valley, based on your profile.

 

7. What glacial feature is Lake Fork Valley?

 

Mastering GeologyTM

Looking for additional review and lab prep materials? Go to www.masteringgeology.com for Pre-Lab Videos, Geoscience Animations, RSS Feeds, Key Term Study Tools, The Math You Need, an optional Pearson eText, and more.

 

How has technology influenced ethical decision-making in healthcare?

/0 Comments/in /by

How has technology influenced ethical decision-making in healthcare?

After your answer, In a separate page Give your opinion on two different paragraph to Tiah Denton and Tiffany Laubach

Tiah Denton

Technology has influenced ethical decision-making in healthcare by the rapidly changing medical technology and availability of high tech and changing practices of doctors over the course of time has evolved the way healthcare is being produced today. Today’s medical technology is more advanced, more effective, and also more costly than ever before. This makes the healthcare industry have an increasing demand for high technology diagnostic facilities to have conflict with medical necessity and social justice which all ties into ethics. Current trends in health care decision making support a transition from a rationale based primarily on resources and opinion to a rationale derived from research.

It is important to recognize the impact of developing a new health care technology within the healthcare system. Demands for increased productivity despite small financial resources brings up cost effectiveness in healthcare. Most issues within decision making are cost versus benefit analysis. It is very difficult to place a dollar value on a person’s life especially when it comes to decisions made within healthcare.

The ethical issues on medical technology and availability are broad. Before any technological changes were made ethics and medicine were not often in conflict. The providing physician would attempt to save lives when he or she could, but technology was limited so this made practicing more along the lines of ethics. Now since technology is available and constantly changing, physicians have the options to keep life going for an unknown periods, undermining distinctions between life and death.