sfairfield's blog

         First the extraction was performed. Ground nutmeg (0.995 g, 2.573 mmol), tert-butyl methyl ether (3.0 mL, 251.843 mmol), and three boiling chips were placed in a round-bottomed (RB) flask, and the distillation column was attached to the RB flask using a black connector. The flask was lowered completely into the aluminum black of the hot plate, set to 250 °C. Carefully adjust the position of the flask so that the mixture boils very gently. The mixture in the flask was heated to boiling for 10 minutes, then removed from the heat and allowed to cool to room temperature. A micro-scale filtration assembly was prepared, with a 25 mL Erlenmeyer flask placed underneath. The contents of the RB flask were transferred gradually via pipet into the filtration apparatus. A rinse was done on the remaining solid in the RB flask using fresh tert-butyl methyl ether (2.0 mL, 16.789 mmol), which was then heated and filtered again. The solvent in the Erlenmeyer flask was evaporated until only crude trimyristin remained in the form of a gummy yellowish solid.

          In this experiment, a purified sample of 1, 2-diphenylethane-1, 2-diol was obtained through the reduction of benzoin with sodium borohydride and the recrystallization of the product with acetone, resulting in 71.73% yield. The product was identified to be 1, 2-diphenylethane-1, 2-diol via TLC analysis and comparison of the experimental melting point to the known melting point. The known melting point of 1, 2-diphenylethane-1, 2-diol is 138 °C, while the experimental melting point was 135-137 °C. That the experimental range is slightly lower than the known range indicates the presence of impurities in the sample, but the relatively narrow experimental range indicates that whatever impurities remain in the final sample are likely present in only small amounts. During TLC analysis, visualization was achieved via short-wave UV light and iodine staining. Iodine produced yellow stains when reacted with the pure benzoin sample, but not the samples of only the recrystallized or crude product. This contributed to the identification of the spots derived from a mixture of benzoin and my experimental samples. Rf numbers were obtained for benzoin, the crude product, and the recrystallized product. Higher Rf numbers indicate higher polarity. Benzoin is less polar than 1,2-diphenylethane-1,2-diol because alcohols are more polar than carbonyls and 1,2-diphenylethane-1,2-diol has two alcohol groups where benzoin only has one. Since benzoin is less polar, it would be expected to travel farther on the TLC plate and have higher Rf values because it has less absorption with the polar silica gel on the TLC plate than 1,2-diphenylethane-1,2-diol. In the experimental TLC analysis, spots derived from benzoin did move further than spots derived from 1,2-diphenylethane-1,2-diol. 

          The Socioecological Model is a method of categorizing female social relationships through agonism. This is further examined along three social dimensions. The first dimension seeks to establish whether or not a dominance hierarchy is present in the given group being analyzed. A group which lacks a strict hierarchy is defined as egalitarian, in which there are undetectable or poorly defined dominance relationships, or in which the dominance hierarchy is not clear or nonlinear. In these groups, food is often dispersed in a way such that patches cannot be defended, resulting in scramble competition in which the first female to arrive at a food resource may get a larger share of the food simply because she got there first. This means there is nothing to gain from contesting the resource, and thus typically produces weak social relationships in females, with no need for post conflict resolution like grooming. In contrast, a group which exhibits a strict hierarchy is known as despotic, in which there are clearly established, formalized dominance relationships that are usually linear. When there is competition over essential resources, aggressive interactions maintain dominance hierarchy and contest competition is high. High rank can provide priority of access to resources, and potentially higher reproductive success, and may may also result in alliances or affiliative behaviors like grooming. The second dimension aims, once a hierarchy has been observed, to further classify the type of hierarchy present. There may be a nepotistic hierarchy, in which female relatives rank close together due to coalitions and often don’t disperse, or individualistic hierarchies, in which the rank of female relatives are independent of each other, and females do disperse. The third and final dimension seeks to assign the degree of tolerance within the group structure, and generally assumes that as tolerance increases, the severity of aggression decreases while threats toward dominant individuals increases.

          In this experiment, a purified sample of 1, 2-diphenylethane-1, 2-diol was obtained through the reduction of benzoin with sodium borohydride and the recrystallization of the product with acetone, resulting in 71.73% yield. The product was identified to be 1, 2-diphenylethane-1, 2-diol via TLC analysis and comparison of the experimental melting point to the known melting point. The known melting point of 1, 2-diphenylethane-1, 2-diol is 138 °C, while the experimental melting point was 135-137 °C. That the experimental range is slightly lower than the known range indicates the presence of impurities in the sample, but the relatively narrow experimental range indicates that whatever impurities remain in the final sample are likely present in only small amounts. During TLC analysis, visualization was achieved via short-wave UV light and iodine staining. Iodine produced yellow stains when reacted with the pure benzoin sample in lane A of both plate 1 and plate 2, but not the samples of only the recrystallized or crude product in lane B of plates 1 and 2 respectively. This contributed to the identification of the spots derived from a mixture of benzoin and my experimental samples in lane C of both plates, in that the spot that reacted with iodine was likely benzoin, and the spot that did not react with iodine was likely the crude/recrystallized product. Rf numbers were obtained for benzoin, the crude product, and the recrystallized product. Higher Rf numbers indicate higher polarity. Benzoin is less polar than 1,2-diphenylethane-1,2-diol because alcohols are more polar than carbonyls and 1,2-diphenylethane-1,2-diol has two alcohol groups where benzoin only has one. Since benzoin is less polar, it would be expected to travel farther on the TLC plate and have higher Rf values because it has less absorption with the polar silica gel on the TLC plate than 1,2-diphenylethane-1,2-diol. In the experimental TLC analysis, spots derived from benzoin did move further than spots derived from 1,2-diphenylethane-1,2-diol. Benzoin had an average Rf value of 0.717, which is slightly beyond the ideal 0.3-0.7 range. The crude product had an average Rf value of 0.575, while the recrystallized product had an average Rf value of 0.5875. There were two additional spots derived from the recrystallized product, labelled 2 and 3 in lane B of plate 1, with an average Rf value of 0.85. This is well beyond the ideal range of 0.3 - 0.7. These spots could possibly be attributed to impurities in the sample. The Rf values exceeding 0.7 could indicate that ethyl acetate was not the best possible solvent for those substances. 

          Benzoin (0.5 g, 2.0 mmol) and ethanol (4.0 mL, 68.0 mmol) were added to a 25-mL Erlenmeyer flask and swirled gently at room temperature until fully dissolved. Sodium borohydride (0.1 g, 3.0 mmol) was added gradually over the course of five minutes using a microspatula, and the mixture was swirled at room temperature for twenty additional minutes. The mixture was cooled in an ice-water bath, then water (5.0 mL, 278.0 mmol) and 6M HCl (0.3 mL, 9.0 mmol) were added. After fifteen minutes, the mixture was quenched with another addition of water (2.5 mL, 139.0 mmol). The product was collected via vacuum filtration on a Hirsch funnel, allowed to dry on the filter for fifteen minutes, and the crude yield and melting points were recorded. Two milligrams of crude material were set aside for TLC analysis. The remaining crude material was recrystallized in a 25 mL Erlenmeyer flask using 6 drops of acetone. The final yield and melting point were recorded. Approximately two milligrams each of benzoin, the recrystallized product, and the reserved crude product were dissolved in ethyl acetate in three separate vials. The contents of the three vials were used to spot two TLC plates such that one plate contained benzoin, crude product and a combination of those two, while the other plate contained benzoin, recrystallized product, and a combination of those two. The TLC plates were run in 9:1 CH2Cl2:ethanol solution. The spots were visualized using short-wave UV light and an iodine chamber. The Rf values were calculated. 

          In this experiment, acid-catalyzed dehydration of cyclohexanol using phosphoric acid was performed in order to synthesize cyclohexene and analyze the product. Following fractional distillation, the product resulted in a 28% yield of cyclohexene. This low yield could have been caused by a combination of transfer loss, insufficiently thorough mixing during the wash, or incomplete removal of impurities. This product was analyzed through a series of tests to detect the presence of alkenes that would be expected in a successful reaction. The two chemical tests confirmed the presence of alkenes by exhibiting the expected color changes. In the bromine dichloromethane test, the vial containing the product remained clear despite the dropwise addition of the brownish-red chemical, indicating that the alkene reacted with bromine to form a colorless dibromide. In contrast, the vial containing cyclohexane briefly turned a reddish-orange color upon the dropwise addition of the chemical, indicating no reaction. In the potassium permanganate test, the vial containing the product turned brown, indicating the purple chemical reacted with the alkenes to produce a colorless diol and a finely-divided brown precipitate of manganese dioxide. In contrast, the dropwise addition of the chemical into the vial of cyclohexane resulted in a purple solution, indicating no reaction. The product was further analyzed by gas chromatography. The resulting GC trace displayed only one peak of 0.299. IR spectroscopy was also used to analyze the sample. The known absorption frequency for an alkenyl is approximately 3083, and the experimental absorption frequency was 3063.09. The known absorption frequency for an alkene is 1644, and the experimental absorption frequency was 1653.07. The experimental values were close enough to the expected values to confirm the presence of cyclohexene.

The fatal canine retrovirus spreading quickly through the global domestic dog population in conjunction with the limited doses of vaccines available necessitate choosing one mother and litter of a particular breed to receive the vaccine, and the best candidate for this is the labrador retriever. The labrador retriever is among the most common breeds used as both pets as well as work/service animals, and it is one of the healthiest of the larger dog breeds, therefore administering the vaccine to this breed would be the most effective use of it in the time constraints we are presented with. The lab is among the most popular dog breeds not only for families seeking beloved pets, but for people seeking work animals or those with disabilities seeking assistance animals. Certain temperaments and physical traits are preferred for service animals, and labs exhibit the necessary intelligence, energy, and gentle-natured that makes them one of the most common breeds for this kind of work. By giving the vaccine to labs, we would be preserving a breed who performs a vital function for those with illness or impairments. Similarly, they were originally bred for sport, and still display the moderate to high energy level and hardy physique for all kinds of physical labor, whether it be hunting, fishing, or other activities. This allows people to train and use them as work animals, which provides economic benefits. Even when only considering them as pets, by administering the vaccine to labs and preserving a breed that is known to have relatively few health issues and long-lifespan compared to other pure breeds, future dog owners can keep their beloved pets around for a long time and can likely anticipate comparatively fewer vet bills than they would with alternative breeds.

Pearce’s overarching theme this section of the pitfalls of pumping from aquifers, whether it be in the American midwest, North Africa, of Asia, was illuminating and troubling, as he highlighted again and again in each of his examples how quickly and often wastefully groundwater resources are depleted, and how few alternatives there are once those groundwater reserves are gone. The part of this section I found most disturbing was the mass poisoning of the Bangladeshi people due to arsenic contamination of the water wells across much of their country. The statistic Pearce offered, that more than 1 out of 20 deaths in the country were a result of arsenic poisoning, was staggering. I was surprised to learn that these arsenic deposits were naturally occuring, and common in delta regions with new inland sediments and alkaline inland drainage basins, as my first guess would have been that the arsenic levels were related to some form of man-made pollution.

          In this experiment, an acid-catalyzed dehydration of cyclohexanol using phosphoric acid was performed in order to synthesize cyclohexene. Following fractional distillation, the product resulted in 28% yield of cyclohexene. This low yield could have been caused by insufficiently thorough mixing during the wash or incomplete removal of impurities. This product was analyzed through a series of tests to detect the presence of alkenes that would be expected in a successful reaction. The two chemical tests confirmed the presence of alkenes by exhibiting the expected color changes. In the bromine dichloromethane test, the vial containing the product remained clear despite the dropwise addition of the brownish-red chemical, indicating that the alkene reacted with bromine to form a colorless dibromide. In contrast, the vial containing cyclohexane briefly turned a reddish-orange color upon the dropwise addition of the chemical, indicating no reaction. In the potassium permanganate test, the vial containing the product turned brown, indicating the purple chemical reacted with the alkenes to produce a colorless diol and a finely-divided brown precipitate of manganese dioxide. In contrast, the dropwise addition of the chemical into the vial of cyclohexane resulted in a purple solution, indicating no reaction. The product was further analyzed by gas chromatography. The resulting GC trace displayed only one peak of 0.299. IR spectroscopy was also used to analyze the sample. The known absorption frequency for an R-C=C-H bond is approximately 3083, and the experimental absorption frequency was 3063.09. The known absorption frequency for a C=C bond is 1644, and the experimental absorption frequency was 1653.07. The experimental values were close enough to the expected values to confirm the presence of cyclohexene. 

           A hot plate was turned on and set to 250 °C. Cyclohexanol (2.0 grams, 20 mmol) was pipetted into a 5 mL round-bottomed (RB) flask RB flask. A buret was used to add phosphoric acid (0.5 mL, 9 mmol) to the RB flask. Boiling chips were added to the RB flask. A fractional distillation was performed on the liquid mixture inside the RB flask at a rate of one drop every 20-30 seconds. The temperature was recorded at the time of the first drop, and again once every four drops after that. The distillate was collected at 68°C. The liquid mixture was distilled until approximately 10% of the original volume remained in the flask. The contents of the collection vial were pipetted into a test tube, and a work-up was performed. The mixture was washed by adding 1 mL of water to the test tube, mixing thoroughly, and removing the lower, aqueous layer. This process was repeated with 1 mL of NaOH and 1 mL of NaCl. The contents of the test tube were pipetted to a new vial. Several CaCl2 spheres were added to the vial until the CaCl2 spheres no longer clumped together. After being transported to a third and final vial, the mass of the liquid was recorded. Samples were taken of the liquid to be analyzed by gas chromatography and infrared spectroscopy. With the remaining contents of the vial, two chemical tests were performed. First, 0.5 mL of cyclohexene product was added to one vial, and 0.5 mL of cyclohexane was added to a second vial. Three to four drops of bromine in dichloromethane was added to both vials and the resulting color changes were recorded. Finally, 0.3 mL of cyclohexene were added to one vial and 0.3 mL of cyclohexane were added to a second vial. Two to three drops of potassium permanganate were added to both vials and the resulting color changes were recorded.