A client has been given a prescription for levodopa-carbidopa for her newly diagnosed Parkinson’s disease. She comments, however, that her friend was given a prescription for “plain levodopa.” What would you explain to this client about her prescription?

clc; clear;for x = 1:1:2    for y = x:-1:1        fprintf(‘x’);    end    fprintf(‘y’);end

The schematic below shows a refrigerated cooling loop in which pure 1,1 difluoroethane (R-152a) is used as the refrigerant to cool a process stream containing a mixture of hexane and toluene.  Simulate this system using Aspen Plus with the Peng Robinson Equation of State.   The system should be modeled initially where you do not actually connect the loop at the discharge of the compressor but instead specify the input into the condenser (stream 1) and then have the output from the compressor be calculated as stream 1a as shown in the modified PFD below. The following may be assumed: Refrigerant Loop The flow of R-152a refrigerant (stream 1) is 150 kmol/hr and enters the condenser at 12 bar and from the compressor. The temperature of the stream can be assumed to be 85 C initially. Condenser Cooling water (CW) enters the condenser heat exchanger at 30 C, 2.5 bar and a flow rate of 4000 kmol/hr and cools the R-152a stream. The condenser is to condense and sub-cool the hot R-152a refrigerant 5 oC below its boiling point (stream 2) . This should be modeled as a heat exchanger using a HeatX block. The water side has a pressure drop of 0.5 bar and the refrigerant side has a pressure drop of 1 bar. Expansion Valve The valve should drop the R-152a refrigerant to a pressure of 3 bar (stream 3) and can be found in the Pressure Changers group of Aspen Plus. Evaporator The hexane toluene mixture (Process stream) is cooled in the evaporator and enters at 45 C at a pressure of 2 bar is 60 mole% hexane and 40 mole% toluene. The flow rate of the process stream is 340 kmol/hr. The evaporator cools the hot hexane / toluene mixture by evaporation of the cold R-152a liquid to a saturated vapor state (stream 4). It should also be modeled as a heat exchanger using a HeatX block The pressure drop across the evaporator is 1 bar for the R-152a side and 0.5 bar for the hexane / toluene side. Compressor The compressor is a single stage unit that can be specified using the ASME isentropic model in Aspen with a 75% isentropic efficiency. It will compress the R-152A gas to 12 bar (stream 1a).   A) Find the duty of the condenser (cal/sec) ______________ B) Find the brake horsepower (kW) of the compressor______________ C) Find the area (m2) of the evaporator ______________ D) Find the vapor fraction of the refrigerant at the discharge of the valve ______________ E) Find the gas temperature in stream 1A (oC) ______________  

The volumetric flow rate of the fresh aqueous NaOH feed is GPM.  Using material balances determine the wt% of NaOH in the fresh aqueous NaOH.  Assume that specific gravity of pure NaOH from Table B.1 can be used and the method of weighted average approximation for density of a liquid mixture must be used. Your answer has to be within 

Questions 2-6 refer to the statement and information given below. In the manufacture of paper, logs are cut into smaller wood chips that are digested with an alkaline solution to make wood pulp. In one steady state process, logs are composed of 35 wt% water, lignin, insoluble inorganic impurities, and cellulose.  The cellulose content of the logs is 42 wt% on a dry basis. They are cut into wood chips and are continuously fed to a digester unit.  A fresh feed of aqueous NaOH solution is mixed with a recycle stream and fed to the digester as a second input. This combined alkaline liquid solution (stream 3) contains 30 wt% lignin.  While none of the cellulose and the insoluble inorganics from the wood chips dissolve in the alkaline liquid, all of the lignin from the chips is solubilized into the alkaline solution.   The single output from the digester is a solid-liquid slurry that is sent to a filter unit along with a stream (5) of pure water as a fresh feed.  The primary product stream 6 is removed at a rate of 100 ton/day of wet wood pulp containing 60 wt% cellulose, some insoluble species, and a small amount of water.  No NaOH or lignin leave in the wet wood pulp.  The liquid filtrate (stream 7) is split into a recycle and a purge, which is removed from the process as a waste stream 9. For every pound of wood chips fed to the digester, two pounds of alkaline solution is fed to the digester.  The amount of pure water required for the wash stream 5 is 5% of the total mass of slurry (4) fed to the filter. On your pdf submission in Test1_part2, draw a clearly labeled schematic that shows the above information. Without solving any material balances, determine the degrees of freedom for the filter unit. In the pdf upload in Test1_part2 you must briefly explain your answer by indicating the source of unknowns and source of independent equations. The explanation must be consistent with your labeled schematic for credit.

The most radiolucent structure of a tooth is the:

To obtain low, long-scale contrast on a radiograph, the kVp to use would be: 

Which of the following is a form of ionizing radiation? 

The occlusal plane of the arch being radiogreaphed should be: 

The operator must avoid: