Thin Lenses Lab Report Essay Example

Thin Lenses Lab Report Essay Example Thin Lenses Lab Report Paper Thin Lenses Lab Report Paper As reaction is reversible, removal of water or the addition of an excess of one of the reactants (cheaper one) drives the reaction towards formation of ester. Excess carboxylic acid is used) Adding excess arbitrarily acid is preferred as it is easier to separate carboxylic acid and ester compared to removing water t] solvent used is (Chocoholic), as water is insoluble in the solvent, so reverse reaction will not take place D using concentrated acid as catalyst rather than aqueous drives equilibrium to the right Reactivity of alcohol: COUCH > primary > secondary > tertiary > phenol In the reaction, no anion can exist, as it is in acidic condition, or acid will react Why dilute the reaction mixture after refluxing? When it is diluted, the ester will be depredation anion and thus enervative as electrophoresis Why sodium bicarbonate is added? To remove excess carboxylic acid and sulfuric acid in mixture Why add brine? Brine is added to remove any water in the mixture as the by product Anhydrous sodium sulfate is added to dry the ester For IR spectrum: C] 1740. CACM-1 (C=O strong absorption shows there is an ester) 0 3500-3100 cam-1 (lack of broad O-H peak shows substance is not alcohol)

How Itching Works and Why Scratching an Itch Feels Good

How Itching Works and Why Scratching an Itch Feels Good Humans and other animals itch for a variety of reasons. Scientists believe the underlying purpose of the annoying sensation (called pruritus) is so we can remove parasites and irritants and protect our skin. However, other things can lead to itching, including drugs, diseases, and even a psychosomatic response. How Itching Works While drugs and disease typically stimulate itching because of a chemical response, most of the time the sensation is a result of skin irritation. Whether the irritation starts from dry skin, a parasite, an insect bite, or chemical exposure, the itch-sensing nerve fibers (called pruriceptors) become activated. Chemicals that activate the fibers may be histamine from inflammation, opioids, endorphins, or the neurotransmitters acetylcholine and serotonin. These nerve cells are a special type of C-fiber, structurally like the C-fibers that transmit pain, except they send a different signal. Only about 5% of C-fibers are pruriceptors. When stimulated, pruriceptor neurons fire a signal to the spinal cord and the brain, which stimulates a rubbing or scratching reflex. In contrast, the response to the signal from pain receptors is an avoidance reflex. Scratching or rubbing an itch stops the signal by stimulating pain receptors and touch receptors in the same region. Drugs and Diseases That Make You Itch Since the nerve fibers for itching are in the skin, it makes sense most itching starts there. Psoriasis, shingles, ringworm, and chicken pox are conditions or infections that affect the skin. However, some drugs and illnesses can cause itching without underlying skin irritation. The antimalarial drug chloroquine is known to cause severe itching as a common side effect. Morphine is another drug known to cause itching. Chronic itching can result from multiple sclerosis, certain cancers, and liver disease. The ingredient that makes peppers hot, capsaicin, can cause itching as well as pain. Why Scratching an Itch Feels Good (But Isnt) The most satisfying relief for an itch is to scratch it. When you scratch, neurons fire pain signals to your brain, which temporarily overrides the itching sensation. The feel-good neurotransmitter serotonin is released to provide relief from the pain. Essentially, your brain rewards you for scratching. However, a study conducted at Washington University School of Medicine in St. Louis indicates scratching ultimately intensifies the itch because serotonin binds 5HT1A receptors in the spinal cord that activate GRPR neurons that stimulate more itchiness. Blocking serotonin isnt a good solution for people suffering chronic itching because the molecule is also responsible for growth, bone metabolism, and other key processes. How to Stop Itching So, scratching an itch, while pleasurable, is not a good way to stop itching. Getting relief depends on the cause of the pruritis. If the issue is skin irritation, it may help to cleanse the area with a gentle soap and apply an unscented lotion. If inflammation is present, an antihistamine (e.g., Benadryl), calamine, or hydrocortisone may help. Most pain relievers dont diminish itchiness, but opioid antagonists  offer relief to some people. Another option is to expose skin to sunlight or ultraviolet light (UV) therapy, apply a cold pack, or apply a few electrical zaps. If itching persists, its a good idea to see a doctor to check for underlying medical conditions or itching in response to a drug. If you absolutely cant resist the urge to scratch, try rubbing the area rather than scratching it. If all else fails, a German study indicates you can lessen itching by looking into a mirror and scratching the corresponding non-itching body part. Itching Is Contagious Are you getting itchy reading this article? If so, its a completely normal reaction. Itching, like yawning, is contagious. Doctors who treat itchy patients often find themselves scratching as well. Writing about itching leads to itchiness (trust me on this). Researchers have found people attending lectures on itching scratch themselves a lot more often than if they were learning about a different topic. There may be an evolutionary advantage to scratching when you see another person or animal do it. Its likely a good indicator you might want to check for biting insects, parasites, or irritating plants.

Suit Sales and Production in UK Research Paper Example | Topics and Well Written Essays - 3250 words

Suit Sales and Production in UK - Research Paper Example The store must there take advantage of the consumers who prefer luxurious good or even take advantage of a decline in the price of its goods in order to increase demand for its products in order to increase sales and therefore increase profits. Twenty consumers were interviewed in order to find out what level of price they were willing to pay for a suit, the respondents were men and each respondent was interviewed for the purpose of collecting data, after randomly selecting a sample of 20 individuals who were to volunteer for the study it was found out that the mean price for the suits that the consumers were willing to pay was lower than the prevailing market prices. Suit sales involves the purchase of these product at wholesale prices and then reselling them at a profit, the level of sales will depend on the prices attached to the product, however this will depend on the consumers preferences, some consumers may prefer high priced good because they have the assumption that the high price is a sign of quality. We will assume that we produce for the medium class individuals who are the majority in the market, using this assumption we will then assume that the store will only sell men suits whose study is accompanied in this paper, through the consideration of all the costs involved in sales we will be in a position to determine expected sales levels and also profits. Methods: This study involves two methods of collecting data. The first form of data collected was to collect the consumer's willingness to pay which involved a random sample of twenty who were involved in a face to face interview. The interview involved the collection of data aimed at determining the consumers willingness to pay, also it contained finding out how frequently consumers purchase suits. All the respondents were to be men due to our first assumption and this sample was collected randomly. The second study was to determine the price level of existing companies in the market, due to time constraints and financial constraints the best method for collecting this data was to be online, data on the prices of these suits was done through the official websites Top shop, Burton, Marks Spencer, Austin reed store, Armani and Hugo Boss. The choice of stores was in such a way that the study considered the various what segment the stores targeted depending on the income group, low pricing stores include top shop and Burton, medium priced stores include Marks Spencer and Austin reed store and finally the high pricing stores include Armani and Hugo Boss. Results: From the sample of twenty data was collected and the willingness to pay of these consumers was determined, there were variations in the data collected depending on the consumers preferences and economic class, the data collected is summarised in the table below: F X FX frequency class mid point price range class 0 to 100 2 50 100 101 to 200 14 150 2100 201 to 300 3 250 750 300 to 401 1 350 350 total 20 3300 mean 165 From the twenty respondents only 2 people agreed that they would pay 0 to 100 pounds for a suit, 14 agreed that they were willing to pay 101 to 201 pounds for the same suit and 3 respondents stated that they would pay 201 to 300 pounds and finally only one respondent agreed that he was willing to pay 0ver 301 pound for a suit. The data was grouped data and after analysing the data the mean price

The Impact of Death on a Child Essay Example | Topics and Well Written Essays - 1000 words

The Impact of Death on a Child - Essay Example Apparently, the dramatic situation at home when they discovered my grandmother had died; during a nap, so they thought she was sleeping for quite some time before they found her and came to a consensus that she was, indeed, dead, warranted forgetting to pick me up. At the time, though, it felt like they forgot my existence. My mother finally arrived looking tormented, even to my young eyes. I started crying as soon as she got out of the car and I saw her swollen eyes and reddened face, the deep creases set around her mouth. She did try to comfort me as best she could, given the situation, but her own suffering just added to my fear. We both cried the entire drive home despite the fact that she never actually told me my grandmother had died, perhaps she thought my immature emotions could not handle this information or maybe she could simply not bear to say the words, either way I was puzzled nonetheless and my tears were just a knee jerk reaction to the intense emotions of my mother, it is always scary for a child to see their parent distressed. When we finally arrived home (the seven-minute drive seemed like hours to me at the time) our entire family was at our house, yet, the packed bungalow was silent. Perhaps the state my mother and I led them to believe I had already been told, but the truth was I wondered and waited for my "Nana" for days before I understood she was never coming back. Looking back at this time I remember a dark and menacing atmosphere where I just tried to stay out of people's way (our house was the headquarters for all grief, big and small) and try and figure out what everything that was going on meant and, mainly, where my 'Nana' was and when she would be coming home. I recall relating the idea of my grandmother's return to one of my older cousins whose parents had come by to 'let it all out' (a phrase I'd overheard my mother using when one of our guests would buckle, allowing their face to contort as their pain cascaded down their cheeks); I think I simply mentioned an activity I would partake in as soon as my grandmother returned and I was met with the cruel and mocking laughter and was told she wasn't coming back, she was dead and that meant asleep forever.

The Hobbit Questions Essay Example for Free

The Hobbit Questions Essay 1. The first three chapters reveal Bilbo’s â€Å"ordinary world†, how he is comfortable and relaxed with his same old life, then the â€Å"call to adventure†, when Gandalf shows up and asks Bilbo for his help and Bilbo’s â€Å"refusal of the call†, and â€Å"meeting with the mentor† was when all the dwarves and Gandalf took over Bilbo’s house, then the morning after the â€Å"crossing the first threshold† is revealed when Bilbo leaves his house and town accompanying the dwarves into the new mysterious world. 2. The Hero – Bilbo Baggins, he is the main character, â€Å"The Hobbit†. Mentor – Gandalf, he is very wise, he guides and helps Bilbo. 3. Bilbo’s â€Å"ordinary world† is his house and town, and Bilbo crossing the threshold is when he enters the unknown world, which is when he accompanies the dwarves without proper preparation and encounters his first enemies, the trolls. 4. Smaug, â€Å"The Shodow†, is introduced in the dwarves’ story as the dragon that drove all the dwarves out of their mountain and claiming their treasure. Smaug’s flaming breath can scorch a city, his huge wings can carry him great distances, and his armor-like hide is almost impenetrable. Smaug can also speak and possesses a dark, ironic sense of humor. 5. At Chapter one, in Bilbo’s â€Å"Ordinary World† food wasn’t the issue at all, Bilbo’s little party had lots of food and everyone ate. At Chapter 2 food was very limited and was hard to find. Chapter 5 1. I believe that Gollum is the â€Å"Shapeshifter†, he might not change his look but he is two-faced, as if there are 2 people in his little body, which disrupts Bilbo from his adventure. 2. In Chapter 5 Bilbo is alone without Gandalf or the dwarves to assist him and he has to deal with Gollum all by himself. This helps Bilbo transform and grow into a smarter, more courageous and confident little â€Å"Hero† by making his own decisions the â€Å"right† decisions, for example he could’ve killed Gollum but he felt bad and let him live. 3. The Hobbit is a children’s story and since Chapter 5 seems to be a dark scary place Tolkien had to use something to enlighten the mood and he used riddles and he made Gollum have almost like 2 sides, a â€Å"good† and â€Å"bad† side. Up to Chapter 14 1. Bilbo had to overcome trolls in the forest, goblins in the misty mountains cavern, Gollum in the tunnels bellow, the goblins’ Wargs chasing the group down, giant spiders in Mirkwood, being then captured by the wood elves, dealing with Smaug in his lair. 2. In the beginning Bilbo Baggins is very home-sick, he wanted to be back in his â€Å"ordinary world†, but the Took in him made him want to continue with the journey. After every challenge, enemy or problem Bilbo overcame he became smarter, making better decisions, confident and courageous, making him less scared to move forward and fair, being caring towards all. 3. Bilbo was hired to be a â€Å"burglar† and most of the crew thought of him being useless although he ended up being far more than that, he saved his crew countless number of times from their enemy, he also was doubting himself a whole bunch in the beginning, he then overcame one problem at a time, building his inner confidence, and without Bilbo and his perks (the ring, his fairness and decision making skills) his crew would’ve gone nowhere.

Graduation Speech: Dont Forget Where You Came From -- Graduation Spee

Good afternoon, I would like to begin by thanking the staff for the privilege of speaking before you on this bittersweet day. It seems like this past year has been a jumble of excitement, reminiscence of the past and uncertainty for the future. After dreaming about graduating since we jumped off the bus on the first day of kindergarten, it's finally here. With the years of number two pencils, group projects and final bells behind us, we find ourselves on the threshold of our future. Yet, it's difficult not to timidly glance back at our past and wonder if we are prepared for what lies ahead. Are we ready to face that thing called reality which our parents and teachers have constantly warned us about? I was unsure if I would be prepared to face this world which exists beyond the doors of high school until a recent incident changed my mind. It forced me to put all of my accumulated knowledge from high school to the test in order to survive. I wish I could say this experience happened to me when I was a silly freshman; unfortunately it was only a few months ago. It began with a routine trip to the high school to pick up my brother from a basketball game one cold, January evening. I arrived to find the game was long over, although at the time I didn't know that he had already gotten a ride home. I went looking for him, taking a shortcut fr om the gym through the courtyard. As I stepped into the frigid air, the door quickly clicked shut behind me. I strode briskly across the courtyard to the double doors in the old commons, only to find they wouldn't budge. Remaining calm, I tried the doors next to them and the gym doors; they were also locked. My heart began to race as I tried every door and gate in that courtyard, only to find I wa... ...e world, but also the memories and lessons from each other. Every time we lent our shoulder for somebody to cry on, laughed even when the joke wasn't funny or cheered loudly whether our team was ahead or not, we were teaching each other important lessons. This type of knowledge is just as necessary as math, science and history to carry with you in the future. So, when you step onto your college campus, begin your first day of work or travel the world this fall, be confident in your abilities and intelligence. However, as you drive into your future, remember to check your rearview mirror every so often so you don't forget where you came from. Laugh aloud when you mess up or lock yourself in a dark courtyard, for these experiences will become the lessons and memories which you pack into the trunk of your car to strengthen you as you drive down the road of life.

A V R Essay

Appearance vs. reality explores how the more persistent illusion will triumph over what the individual want to be true. While reality is persistent, appearance it is less convincing as it based upon the fragile network of an individual’s values, expectation and deepest desires. Pleasantville (1998) directed by Gary Ross examines this idea through the protagonist who escapes his troubles and unforgiving reality to Pleasantville; a fake world that reflects his utopic vision and 1950’s American society.Similarly Robert Frost’s poem â€Å"Birches† shows no matter how hard he tries to escape his reality to a better illusion he was made for himself, reality is persistent and will always bring him back. In Pleasantville the idea that reality will triumph over appearances is shown by David’s negative view of his family and yearning for the family he sees in Pleasantville.. The appearance that David sees in Pleasantville is peace, calm, relaxing and great bu t in his reality it is the opposite of Pleasantville as he has difficult problems with his family.This is shown by of contrast of the perfect family living the American Dream in Pleasantville compared to David’s own family. The montage of shots of all the members of Bud’s family in Pleasantville contrasts heavily to the empty and wide shot of David and just his mother, emphasising how his family is so different from his ideal family on Pleasantville. Although David wants to become part of Bud’s family, he realises this is just an illusion based on his desires.This is clear when he realises Bud’s family isn’t as perfect as it seems through the uncomfortableness he feels with the repetition of the word â€Å"swell† to describe what he thinks is good and returns to his persistent illusion of his real family, his mother. Reality is shown to be the more persistent illusion through the corruption of values in Pleasantville. Jennifer instigates the corruption of Pleasantville by bringing in values and practices of her reality to the untainted illusion of Pleasantville.When Jennifer has sexual intercourse with skip on Lover’s Lane, there is a change in the scenery shown in the close up shot of the grey rose turning into a bright red. The previous monotone colours represent†¦. And the red represents†¦.. This shown that reality is more persistant than the illusion of appearance as†¦. FILL IT IN! Another example is shown through when Betty sees Mr. Johnson for the first time and she starts to feel different from seeing him. The technique that is used is contrast of colour and grey background. The wife changes as she ealise her true feelings, and it is this persistent emotion that overcomes her role as the faithful wife in the American Dream. This shows the wife is being seeing her true feeling and her true reality from Mr. Johnson, ultimately breaking the illusion of appearances . Similarly, in Frost’ s â€Å"Birches†, reality is illustrated as persistent reality that will triumph over any illusions of appearances but does this through the poet who reminisces about his childhood past with the birches tree. The poet feels a strong connection with the illusion he has made of the birches as a sentimental figure of his past time.He does this by portraying birches during the autumn time as †like girls on hands and knees who throw their hair before them†¦ to dry in the sun†. The personification combined with simile to reinforces the illusion the poet has created from his expectations and desires. However,. reality attempts to bring the poet back from his constructed illusion that has been â€Å"shattered and avalanched†¦. [reduced to] broken glass to sweep away†. This is emphasised by the â€Å"black† branches surrounding the â€Å"snow white trunk†.The black branches symbolise the persistent illusion of reality trying to bring him back to what is more real surrounding the white trunk that symbolises the dying purity and untainted illusion he has created of the birches, showing that reality is more persistent than appearances. Unlike Pleasantville, where David does not want to return to the persistent callings of his reality , the poet in â€Å"Birches† realises that although he can visit his â€Å"heaven† using his childhood memory of the birches, he would â€Å"then come back to it [earth] and begin all over†.The nostalgic tone emphasises that he cannot go back to his illusion of appearances as he recognises the reality is more persistent. Through the close study of the Ross’s â€Å"Pleasantville† and Frost’s â€Å"Birches† it is clear that reality is more persistent than appearances. Pleasantville shows the corruption of values and the perfect family based on the American dreams to shows how reality will triumph over appearances similarly â€Å"Birches† us es the poet reminisces that frost can visit his appearance but when he returns to his reality he understands that reality is the more persistent one.