CdSe/CdS core/shell nanocrystals were prepared by organometallic method [26] using Cadmium oxide (CdO 98.9%) was provided by Fluka. Sulfur powder (S 99.5%), Selenium powder (Se 99%), Trioctylphosphine oxide (TOPO 97%), Trioctylphosphine (TOP 90%) Hexadecylamine (HDA 97%) were purchased from Aldrich. Stearic acid 98%, Acetone 98%, Oleic acid (OA) 98%, Methanol 99%, Toluene 99% were from united chemical Lab. All chemicals and solvents had been used as received while not more purification. In the experiment, OA was used as the ligand of and TOP was used as the ligand of the Se precursor.
The two essays that I choose for the synthesis essay are Parkinson’s Alley by Joy Horowitz and The Environmental Issue from Hell: Global Warming Is the Great Moral Crisis of Our Time by Bill Mckibben. Parkinson’s Alley is about residents in California’s Central Valley town of Visalia who have been diagnosed with Parkinson’s. This part of California has the highest number of people diagnosed with the neurodegenerative disease. The pesticides that are used in the surrounding farms seeps into the water that the residents use every day, causing them to get the disease. The Environmental Issue from Hell: Global Warming Is the Great Moral Crisis of Our Time is about how global warming is a moral crisis that, if not combated
This lab could have contained errors. The errors could have happened when performing the lab. Some of the possible errors in this lab are:
One is to determine the gap energy of cadmium sulfide semiconductor thin film using the equation: Eg = h.c/
1. I am used to make die castings for use in the electrical, automotive, and hardware industries. Who am I?
Background of the Chemistry: Cadmium Selenide is an inorganic compound that is widely used for research on nanoparticles. Cadmium Oxide is an inorganic compound that is mostly used for creating other cadmium compounds because it crystallizes in a lattice like that of NaCl. Selenium is an element that has nonmetal properties, but it is rarely ever found in its pure state, it is often found as a compound. Both, selenium and cadmium are used to synthesize the CdSe used in this experiment. Although these materials can be very hazardous, it has been proven that using these items are the best option for this synthesis. The reasoning for this includes the temperature needed to grow them and they have higher
For sample A, I predicted that it was either potassium or sodium because the chloride salt before the experiment was very similar in texture, size, and colour, (small, white/clear, powdery grains). While burning, all three of the samples produced an orange flame that became smoother at the end. As I anticipated, sample A turned out to be potassium. Although, I had trouble distinguishing whether the sample was K or Na because of how similar they were throughout the whole process. As for sample B, my prediction was that it was either zinc or lithium, since they were the only element samples that were wet because water vapour was absorbed from the air. In addition to that, sample B had a bright crimson/orange flame, just like Li, although the overall shape and length of the flame was more similar to Zn. It turned out that sample B is a Zn ion and a Li ion. This seems accurate because the sample had many similarities with both elements, although I wouldn’t have guessed that it was a mix of both elements. Rather, I blamed my perception and the observations I made.
Potential connections exist between total lightning and mesovortex formation, which is the parent circulation from which QLCS tornadoes are born. Many studies have found that mesovortexgenesis is initiated at low levels by tilting, in downdrafts, of crosswise baroclinic horizontal vorticity (Trapp and Weisman 2003 Part II, Wheatley and Trapp 2008, Atkins and St. Laurent 2009 Part II). Additional studies have found that strong low-level updraft is critical in converging and amplifying vertical vorticity associated with the mesovortex (Schenkman et al. 2012, Atkins and St. Laurent 2009). Trapp and Weisman (2003 Part I) also found that the amount of wind shear had large implications on mesovortexgenesis. As wind shear increased in both magnitude and
On 1/7, the Alky started to only process FCCU BB and no longer process Coker BB. Alkylation chemistry neither likes contaminants nor diluents. Contaminants are direct acid consumers. The more contaminants in the feed, the more often the unit will be at an acid constraint. Diluents do not reaction in alkylation chemistry but they take up space and decrease the effective area for isobutane and olefin to contact. With less contact, side reactions like polymerization are more likely to occur; polymerization reactions are a direct acid consumer.
Often, when people think about how something did or will revolutionize the world they think of obvious things. Things such as medical advancements, the camera, or even the telephone, but how often do they think of a fabric? Something so basic that it doesn’t even cross the minds of most people when confronted with this question. There is one entirely unique fabric that can be argued to have revolutionized the world, Polytetrafluoroethylene (PTFE). This wonder material has many benefits, but it also has some consequences.
the N-dealkylated tolterodine. The remainder of population is referred to as the “extensive metabolizers.” Pharmacokinetic studies revealed tolterodine is metabolized at the slower rate in poor metabolizers when compared to extensive metabolizers; these results in higher serum concentrations of the tolterodine and negligible concentrations of 5-HMT.
L-Theanine as one of the nootropic ingredients of Mind Lab Pro is an amino acid compound thought to increase alpha brainwaves, which reduces stress & anxiety while enhancing alertness. It also protects brain cells against damage that makes them fail and eventually shut down
PTEN (Phosphatase and tensin homolog) is a phophatase known for negatively regulating the pathways downstrteam of AKT (protein kinase B), which are involved in cell survival, proliferation and migration. In the central nervous system (CNS), Pten mutation can cause hypertrophy and ectopic ramification of dendrites, macrocephaly and increase of anormal synapses. Along with these morphological anomalies, alterations in memory processes, synaptic plasticity and neurogenesis are also observed. Accordingly, there are several diseases associated to Pten mutations, including autism spectrum disorders. On the other hand, physical exercise when practiced during pregnancy can provide beneficial effects to the offspring, including improved short-term memory and learning and
Americans today are becoming an obese nation. As more people are becoming obese, there are more complications that these people are facing such as their health. To lower obesity in our country, there are a lot of weight management products out in the market that are targeting to help people to loss weight. One of the weight management product is Lipozene pills. Lipozene is a diet pill that claims to help “you” lose weight with no strict diets and easy to use. It has all natural ingredients that are safe, which will make you reduce hunger and make you feel fuller and faster. The ingredients in lipozene is made from Konjac root known as Glucomannan. Glucomannan is a water-soluble fiber that acts as a dietary fiber gel in the stomach that will expands and make your stomach feel full so that “you” can eat
The preparation of the selenide organometallic precursor, trioctylphosphine selenide, was done by dissolving 0.1 mol of a selendie shot in 100 ml of trioctylphosphine, therefore resulting in a 1M solution of trioctylphosphine selenide. Dimethylcadmium was used as the other organometallic precursor. The CdSe quantum dots were synthesized via the pyrolysis of dimethylcadmium and trioctylphosphine selenide in the co-ordinating trioctylphosphine oxide solvent. Precursors were injected at 350oC and dots were grown at 290oC. Selective size precipitation was performed with methanol to collect the quantum dots as powders, then quantum dots were redispersed in hexane. 5g of trioctylphosphine oxide was heated until it reached 190oC under a vacuum and
The purpose of this experiment was to perform a wittig reaction, the horner-emmons wittig specifically, reacting an aldehyde with an ylide to make an alkene. This particular variation of the wittig reaction has several advantages: It gives only the trans product; it uses a much milder base that is easier to handle; and it gives a water soluble byproduct which is easy to separate from the product. The reason that these advantages occur is a change in the structure of the ylide. Instead of a tripheylphosphine ylide, we use a diethylphosphonate ylide. The protons are much more acidic and its byproduct is negatively charged.