Radiation Concern

Write a minimum of two paragraphs, minimum of 200 words.
Questions: A patient who is scheduled for an x-ray expressed concerns about being exposed to radiation because he witnessed the effects of radiation on his father, who died of cancer. How should the dental assistant respojvznd to this patient’s concerns?

Geotechnical Mechanics FINAL EXAMINATION

Question # 1 Short Answer questions (15 marks)
1.1 Which of the following unit weights will have the lowest value in soil?
a) Bulk unit weight b) Buoyant unit weight c) Saturated unit weight d) Dry unit weight
1.2 Which of the following soils would have lower hydraulic conductivity?
a) SM b) GC c) GP d) CH
1.3 What is the optimum water content of a soil?
a) The water content at which soil will have the highest permeability b) The water content at which the
soil will have the highest dry density c) Swelling water content d) Shrinkage water content

1.4 How the excess pore water pressure can affect the shear strength of a fine-grained soil?
a) Increases effective stress b) Decreases effective stress c) Increases friction angle
d) Decreases cohesion
1.5 Which of the following factors will decrease the effective stress in soil?
a) Downward seepage b) Upward seepage c) External loading d) Drop in ground water table

Question #2 (15 marks)
a) The dry density of a soil is 1780 kg/m3
. Given GS=2.68, what would be the moisture content of the soil
when saturated? (5 marks)
b) In its natural state, a soil has a bulk density of 2.15 Mg/m3
and a water content of 12% (GS = 2.65).
Would it be possible to compact the above soil at a water content of 13% to dry density of 2.0 Mg/m3? (10
marks)
Question #3 (30 marks)
A layer of sand of 18 m thick overlies
impermeable rock, and a long
cofferdam is formed by driving sheet
piling to a depth of 9 m below ground
surface.
a) If the flow of water through
underneath the cofferdam is 0.3 m3
/hr
per unit length of the dam, what is the
coefficient of permeability of the sand?
b) If the specific gravity of the soil
solids is 2.65 and e=0.7, do you
expect piping downstream of the
cofferdam?
c) Calculate pore water pressures at
points b and f.
Figure 1
Question #4 (10 marks)
Determine the increase in vertical stress at
a depth of 3 m below point X on the Lshaped foundation shown in Figure 2 (plan
view), when the foundation is subjected to a
uniform pressure of 200 kPa.

Question #5 (20 marks)
A building with the net foundation pressure (uniformly distributed) of 330 kN/m2 is supported on a 40 m  30 m
mat foundation located at a depth of 3 m from ground surface. The soil profile is given in the figure below. The
following values were measured from consolidation test for the clay layer: Cc=0.15, Cr=0.03, e0=0.96, p
’=130
kPa).
a) Determine the total settlement under the
center of the foundation due to the
consolidation of the clay.
b) If the water table is lowered 5 m after
the settlement calculated in part (a) is
complete, will the clay layer continue to
consolidate, remain at the same
thickness, or rebound? If the thickness
of the clay layer does change, calculate
the magnitude of the change.

Figure 3
Question # 6 (10 marks)
A sandy soil has a drained friction angle of 34. In a drained triaxial test on the same soil, the deviator stress at
failure was measured at 255 kPa. What is the cell pressure of the test sample?

 

Hazardous Materials Safety
Find some examples of the new Globally Harmonized System of Classification and Labeling
(GHS) label for chemicals you are familiar with and the corresponding National Fire Protection
Association (NFPA) or Hazardous Materials Identification System (HMIS) labels for that
chemical. Which type of label do you think provides the most information to help control risks
associated with the chemical? Do you believe the two labels conflict with each other or
complement each other?
Your essay entry must be at least 200 words in length. APA format.

Hazardous Materials Safety

For this assignment, assume you have been given the task of developing a spill response
program for Acme Chemical Manufacturing, Inc. The company uses chemicals in large
containers to produce specialty chemical blends for clients that they then ship in smaller
containers. Using the existing chemical inventory list, you confirm the following hazardous
materials are present in the following locations:
Chemical Quantity (Container) Location
Acetone (100%) 10,000 gal. (AST) Building 2

Benzene (100%) 600 gal. (5 plastic totes) Storage Room A
Formaldehyde (100%) 1,000 gal. (AST) Storage Room A
Methanol (100%) 500 gal. (5 gal. bottles) Storage Room A
Sulfuric Acid (70%) 250 gal. (2 plastic totes) Storage Room B
AST=Aboveground storage tank
Building 2 is a 15’ X 15’ building with a concrete floor, CMU block walls, and no drainage that is
located adjacent to the main building. Acetone is transferred to the main building through piping.
The room has a portable ABC fire extinguisher on the wall.
Storage Room A is a 20’ X 20’ storage room inside the main building. The plastic totes and glass
bottles are stored on commercial racks on two separate walls inside the room. The aboveground
storage tank (AST) is located in a corner of the room. The room has a concrete floor with CMU
block walls and no drainage. There is a diked area around the AST that can hold up to 1,500
gallons of a liquid. The room has three portable ABC fire extinguishers spread throughout the
room.
Storage Room B is a 10’ X 10’ storage room in the main building. The room has a concrete floor
and CMU walls with no drain. There are no fire extinguishers in the room.
In your written spill response program, address the areas below.
Explain what additional information you would need to perform a risk assessment for the

hazardous materials used at the site. Where could you obtain the necessary information?
After obtaining the necessary information, perform a risk assessment for health on each of the
hazards using the risk assessment matrix in the unit lesson. Report the numerical score for each
hazard.
Discuss which hazard you believe represents the greatest health risk to workers in the area.
Discuss which hazard you believe represents the greatest environmental hazard.
Develop a list of the equipment and personal protective equipment (PPE) that you would
recommend to be procured and maintained for a spill response for each of the hazards.
Explain why you chose each of the pieces of equipment and PPE and where you would store the
equipment and PPE relative to the locations of the hazardous materials.
What level(s) of training do you think would be necessary for members of the spill response team
if you were planning to conduct spill response operations with in-house employees?
Your assignment must be at least three pages in length, not counting the title page and
references page. You must include at least two references to support your assignment.