Atmospheric aerosols

at
Categories
Tags

Question 1 [20 points]

a. Sketch by hands the typical size distribution of atmospheric aerosols in number concentration, surface area concentration and volume concentration and mark on the graphs what are ultrafine particles, fine particles and coarse particles. [6 points]

b. Point out the major difference in the size distribution between number concentration and volume concentration and explain clearly what makes the variation in size distribution. [3 points]

c. Name the major gas-particle and particle-particle interactions for atmospheric aerosols and describe what they are. Indicate clearly how these processes influence the number and volume size distributions. [6 points]

d. It is well-known that the concentration and composition can vary substantially from location to location and from time to time due to the variations in the emission sources, meteorology and a number of other factors. And it has also been reported that the composition (the relative composition) can change with the particle size. For example, it is found that carbons in atmospheric aerosols in an urban environment decrease in the percentage composition with increasing size like PM0.1 > PM1.0 > PM2.5 > PM10. What are the causes? [5 points]

———————————————————————————

Question 2 [18 points]

a. Atmospheric aerosols impair visibility through two types of effect on lights. What are they? Name one of the chemical species common in aerosols that will contribute to these effects. [4 points]

b. It is often that when we report the reduction of visibility due to haze, we have to specify the high RH cases are excluded, e.g. situation with RH > 95%. Why? What high RH phenomenon we want to avoid/minimize? [4 points]

c. A number of emission control measures have been successfully implemented years ago on PM10, like dust emission reduction from power plants, but the visibility was not improved as expected. And in certain occasions, the visibility was continually deteriorating. Why? Please do an analysis on the potential cause. [10 points]

———————————————————-

Question 3 [17 points]

a. PM2.5 is a criteria pollutant that can have immense impact to our health and visibility. It is defined using the aerodynamic diameter. But how is this diameter being defined, i.e. what is the definition of aerodynamic diameter? [2 points]

b. Why is PM2.5 defined using aerodynamic diameter? [2 points]

c. What is the physical meaning of relaxation time of an atmospheric particle? And explain how the relaxation time is associated with the size of the particles. [4 point]

d. Impactor and cyclone are commonly used size-selection devices to separate PM2.5 particles from the particle-laden air. Describe with sketches by hands to illustrate how the separation is achieved with the impactor. Please define relaxation time and explain how the particles separated with an impactor using the relaxation time concept. Be reminded to label the sketches clearly. [9 points]

—————————————————————–

Question 4 [16 points]

a. What are positive artefact and negative artefact for sampling and measurement of aerosols?

Now, for the reaction on the NaCl in the particles collected on filter upon the absorption of acidic gases like
NaCl (aq) + HNO3 (g) -> NaNO3 (aq) + HCl (g)
What are the sampling artefacts to sodium, chloride and nitrate? [5 points]

b. When doing gravimetric measurement on filter samples of PM, we often use Teflon filters but always avoid using glass filter filters. Why? Is it a positive or a negative artefact? [4 points]

c. When doing online size distribution measurement of atmospheric aerosols, it is often set up with the sampling inlet at outdoor while the instrument is installed indoor with air-conditioning. In Hong Kong, it is often over 30C in the summer while the air-conditioned indoor environment is usually kept at temperatures no higher than 25C. What sampling/measurement artefact can cause to the size distribution measurement (i.e. what changes have been made to the atmospheric aerosols in their size distribution when they are sampled into the indoor for measurement)? Please explain. [7 points]

– END-

virtuoso piano player, organist and musician, with his music grasping concertos, show, choral, chamber, instrumental, ensemble and vocal viewpoints.

Mozart was conceived in Salzburg in 1756 to a dad of an aspiring Composer and Violinist; be that as it may, his sister, Nannerl was the kid wonder of the family. At 16 years old, Mozart had before long gotten one of music’s first “independent” experts in spite of holding the status of a gourmet expert in the Court of Salzburg.

Mozart showed up in Vienna in 1781, when he was 25, and wedded Constanze Weber a year later in 1782. During this time he started to put on shows, distribute music and get commission for his dramas. From 1781 to 1791, Mozart composed around 200+ works and merged his notoriety, yet he despite everything needed to show piano exercises in his spare time just as taking in outskirts and obtaining cash to keep up the luxurious way of life he had picked up from his high melodic status.

Mozart made his Sonata for Two Pianos in D major, k. 488, in 1781 when he was 25. It has three developments and is written in a sonata-allegro structure with a “Galant” style that contains interlocking tunes and synchronous rhythms. It was created for his companion Josepha Auernhammer for a presentation they would give together, making it one of Mozart’s couple of organizations composed for two pianos.

47.

Mozart is said to have passed on the fifth of December 1791 at the youthful age of 35, anyway it is dubious what he kicked the bucket from. There are theories of homicide by his companion Antonio Salieri by poison, yet ever-present indications of disease for a mind-blowing duration excused this hypothesis. The Parish register, a book recording christenings, relationships, and internments at a ward church, states he kicks the bucket from an extreme instance of “military fever”.

Mozart was known to have been an evil kid and to have experienced limbs of sickness as he was growing up; from the age of nine years of age he encountered the perilous ailment, potentially known as typhoid fever, just as ramifications of smallpox, tonsillitis, bronchitis, pneumonia, stiffness and gum infection. Mozart’s awful safe framework drives us to the inquiry that if Mozart’s music should mend and improve the psyche and body, for what reason did he experience the ill effects of such extraordinary ailments all through his lifetime.

The Original Study

The Original ‘Mozart Effect’ study was performed and done by three looks into, Frances Rauscher, Katherine Ky and Dr Gordon Shaw in 1993. The investigation depended on thirty-six college understudies from the brain research office at the University of California, Irvine.

The understudies demonstrated a normal score increment of eight to nine focuses on the Stanford-Binet Intelligence Scale in the wake of tuning in to 10 minutes of Mozart’s Sonata for Two Pianos in D Major K.448 (the old style piece was recommended by Daniel Remler). As per Rauscher “The impact endured 10 minutes, and was not found for different spaces of insight, for example, transient memory or spatial acknowledgment. (Rauscher 2018)

48.

This question has been answered.

Get Answer
WeCreativez WhatsApp Support
Our customer support team is here to answer your questions. Ask us anything!
👋 Hi, Welcome to Compliant Papers.
Hi, how can I help?