Farooq

1. Method for measuring the flow rate in a fluid flow (30), particularly a two-phase flow comprising oil, water and gas from a development well offshore, characterized in: performing a temporary transistory shut-off of the fluid flow by means of a valve (33), and recording the fluid pressure at a location (37) immediately upstream of the valve (33) from a moment of time when the valve starts closing to a selected moment of time after the valve is fully closed, and opening the valve to re-establish the fluid flow, and determining the fluid mass flux G according to the ratio ##EQU7## where ρ=fluid density, f=friction factor, d=pipe diameter, t'=a selected moment of time after closure of the valve, Δpf is friction loss recorded at time t and Δpa is pressure surge pressure represented by recorded pressure increase at the moment the valve is fully closed. 2. The method of claim 1, characterized in determining the velocity of acoustic pulse propagation in the fluid by measuring pressure as a function of time during shut-off of the valve by a reference metering means (35) and a metering means (36) located at a known distance downstream of the reference metering means (35), and determining said acoustic pulse propagation velocity according to the equation a=L/t. 3. The method of claim 1, characterized in determining the flow rate and acoustic pulse propagation velocity in a flowing multi-phase medium from a development well by a reference metering means (57) located immediately upstream of the shut-off valve (51) and a metering means (58) located at a known distance upstream of the reference metering means (57). 4. Method for measuring the flow rate of a fluid flow (40) comprising at least two phases, by means of pressure sensors (45, 46) downstream and pressure sensors (47, 48) upstream of a pulse generating means (43), characterized in using a quick-closing valve as said pulse generating means (43), and changing the valve (43) position from substantially open to fully closed, recording the fluid pressure by the pressure sensors (47, 48) and (45, 46) from a time when the valve starts closing to a selected moments time after the valve is fully closed, and then opening the valve to re-establish the fluid flow, determining the fluid flow velocity and specific acoustic velocity according to the ratio ##EQU8## where uN is the pressure pulse propagation velocity downstream and uo is the pressure pulse propagation velocity upstream, and providing the fluid flow velocity u from the formula u=0.5(uN -uo) or by substracting the fluid specific acoustic velocity a from the measured pulse propagation velocity: u=uN -a, and determining the fluid density ρ according to the ratio Δpa =ρaΔu (2) where Δu is the change of fluid velocity, a is the velocity of acoustic pulse propagation in the fluid, thus determining the fluid flow rate G according to the equation G-ρu (7) where u is the fluid flow rate immediately before the valve starts closing.

Abstract Different structured activated carbons were prepared from macadamia nutshell by chemical activation with potassium hydroxide and zinc chloride. The influence of process variables on the carbons' pore structure was studied in order to optimise these parameters. The results were also compared with those previously obtained on the chemical activation of coal. The most important parameter in chemical activation with both chemical agents was found to be the impregnation ratio. Carbonization temperature is the second important variable which had significant effect on pore volume evolution. Under the experimental circumstances studied, the optimum conditions in preparation of carbons with high surface area and pore volumes with both chemical agents are identified.

Abstract In a previous work, the use of a Spanish anthracite for the preparation of activated carbons by chemical activation was analyzed. The results indicated that this raw material is promising for that purpose. In the present paper, that previous work is extended and the effect of different preparation variables on the final porous texture is discussed, such as KOH/anthracite ratio, heating rate, carbonization temperature and carbonization time. Among those different variables studied, the KOH/anthracite ratio seems to be the most important one. In addition, this study introduces an investigation of the nitrogen flow rate, showing that this variable has a very important effect on porosity development. The study confirms that the raw material used is appropriate for the preparation of activated carbons in a single stage pyrolysis process. The proper choice of the preparation conditions allows us to produce microporous activated carbons with a micropore volume up to 1.45 cm3/g and a BET surface area of 3290 m2/g. This work is extended in Part II with a detailed study using NaOH as activating agent and a different preparation method (physical mixing).

Measuring the Flow of a Stream suggested grade levels: 7-12 view Idaho achievement standards for this lesson

Overview: Idaho has more than 93,000 miles of streams, rivers, and creeks. We depend heavily on these waters for irrigation, power, fishing, and other things. Rivers have shaped our landscape. The following activity will expose students to the concept of stream flow. This activity can be done at a local stream as part of a field trip. Objectives: 1. Students will be exposed to the Digital Atlas of Idaho. 2. Students will understand the concept of stream flow. 3. Students will learn how to take quantitative measurements. Materials: Tape measure (meters) Meter sticks Clipboard with pen and paper

Watch (with second hand) Small ball or stick

Procedure: 1. Encourage students to use the Surface Hydrology section Digital Atlas of Idaho. To get there: Click on Atlas Home, mouse-over Hydrology, then click on Ground & Surface Water Concepts. Scroll down and encourage students to read the section on Instantaneous Streamflow Measurement. This section will describe how to measure streamflow. 2. Have a class discussion on the role of streams and their importance in watershed systems. Also mention erosion, organisms influenced by streamflow, human influence, etc. 3. Go outside with the class to give students the opportunity to have a hands-on learning experience. Measure off a 30-meter section of a stream using a tape measure. 4. Float an object (ball or stick) down the 30-meter section and time how long it takes. Repeat two more times and take the average in meters per second. Record all data on a clipboard. 5. Have the students measure the width of stream at three different places and take the average. Use meters. 6. Measure the depth in meters on a line running perpendicular to the stream. Measure in 5-8 locations and take the average. 7. Calculate stream flow using the equation given in the Digital Atlas. Be sure to report your velocity, width, and depth as the averages calculated. Stream Flow = Velocity X Width X Depth (Answer should be in cubic meters per second) 8. Have discussion on stream flow. 1. What did we measure? 2. What time of year is streamflow usually the highest? 3. How could we have measured streamflow more accurately?

Handouts/Activity links: These are links to access the handouts and printable materials. Ground & Surface Water Concepts Related Lesson Topics: Hydrology: Hydrology Topics Lesson plan by James Scannell and Stefan Sommer, 2001

Idaho Achievement Standards (as of 7/2001) met by completing this activity: 351.01.02.03 798.01.02.03 352.01 799.01 357.01 804.01 358.01 805.01

Measuring streamflow In order to accurately determine streamflow, measurements must be made of its width, depth, and speed (velocity) of the water at many horizontal and vertical points across the stream. To develop a streamstage/streamflow relation (rating curve), streamflow must be measured at many different stages. The well-developed rating curve allows for estimation of streamflows at virtually any stream stage. More simply, if a stream is measured at stages of 3.5, 6, 7.1, 9, and 10.2 feet, then an estimate can be made for a streamflow at 8 feet -that is the goal.

For example, let's say we need a measurement of Example Creek when it is at a stream stage of approximately 3 feet. First, someone has to go out to the stream when the stage is near 3 feet. The diagram below shows a cross-section of Example Creek at a 3-foot stage. Note that the stream stage does not necessarily correlate to the actual depth of the stream. Example Creek is about 10 feet wide. The stream-measurement procedure is to go across the stream at selected intervals and measure the total depth and the velocity of the water at selected depths at each interval across the stream. The picture shows a current meter (attached above the torpedo-looking weight), which is lowered into the stream and measures water velocity. The spinning cups on the current meter measure velocity. In the diagram, the hydrologist would take a measurement of how fast the water is moving at every green 'X', and would then determine the areas between all of the measured intervals, such as the one shown by the purple box.

In the diagram, water depth/velocity measurements are obtained horizontally across the stream at 1, 3, 5, 7, and 9 feet (the vertical lines in the diagram). At each location, measurements of velocity and total depth are obtained. Depending on the depth and flow conditions, one or more velocity reading(s) are obtained in each vertical. For our example, a water depth/velocity measurement is obtained at a point 5 feet from the edge of the stream. The total depth is slightly more than 3 feet and velocity readings are obtained at depths of 1, 2, and 3 feet (the 'X's on the 5-foot vertical line). The purple box represents an area that is midway between this measurement point and the measurement points on either side. The purple area is 2 feet across and one foot high, or 2 square feet. The measured velocity at the big X in the purple box is is 2 feet per second. To compute the amount of water flowing in that purple area each second, multiply the area of the purple box times the velocity of the water: (1) 2 feet wide x 1 foot high = 2 square feet (2) 2 square feet x 2 feet per second = 4 cubic feet per second. To compute the total stream streamflow the hydrologist has to create imaginary purple boxes between all of the 'X's and, using the velocity of the water in every box, compute the streamflow for each purple area. Summing the streamflows for all the purple areas will give the total streamflow. Actually, the example above is a simplified explanation of how streamflow is measured. When an actual measurement is made, the hydrologist takes measurements at about 20 points across the stream. The goal is to have no one vertical crosssection contain more than 5 percent of the total stream discharge.