Reach Your Academic Goals.

Join Today to Score Better

Connect to the brainpower of an academic dream team. Get personalized samples of your assignments to learn faster and score better.

Connect to a Paper Expert

How can our experts help?

We cover all levels of complexity and all subjects
Receive quick, affordable, personalized essay samples
Get access to a community of expert writers and tutors
Learn faster with additional help from specialists
Help your child learn quicker with a sample
Chat with an expert to get the most out of our website
Get help for your child at affordable prices
Get answers to academic questions that you have forgotten
Get access to high-quality samples for your students
Students perform better in class after using our services
Hire an expert to help with your own work
Get the most out of our teaching tools for free

The Samples - a new way to teach and learn

Check out the paper samples our experts have completed. Hire one now to get your own personalized sample in less than 8 hours!

Competing in the Global and Domestic Marketplace:
Mary Kay, Inc.

Case study
Read Sample

Reservation Wage in Labor Economics

Read Sample

Pizza Hut and IMC: Becoming a Multichannel Marketer

Case study
High School
Read Sample

Washburn Guitar Company: Break-Even Analysis

Case study
Read Sample

Crime & Immigration

Read Sample

Interdisciplinary Team Cohesion in Healthcare Management

Case study
Read Sample

Customer care that warms your heart

Our support managers are here to serve!
Check out the paper samples our writers have completed. Hire one now to get your own personalized sample in less than 8 hours!
Hey, do you have any experts on American History?
Hey, he has written over 520 History Papers! I recommend that you choose Tutor Andrew
Oh wow, how do I speak with him?!
Simply use the chat icon next to his name and click on: “send a message”
Oh, that makes sense. Thanks a lot!!
Guaranteed to reply in just minutes!
Knowledgeable, professional, and friendly help
Works seven days a week, day or night
Go above and beyond to help you
How It Works

How Does Our Service Work?

Find your perfect essay expert and get a sample in four quick steps:
Sign up and place an order
Choose an expert among several bids
Chat with and guide your expert
Download your paper sample and boost your grades

Register a Personal Account

Register an account on the Studyfy platform using your email address. Create your personal account and proceed with the order form.


Submit Your Requirements & Calculate the Price

Just fill in the blanks and go step-by-step! Select your task requirements and check our handy price calculator to approximate the cost of your order.

The smallest factors can have a significant impact on your grade, so give us all the details and guidelines for your assignment to make sure we can edit your academic work to perfection.

Hire Your Essay Editor

We’ve developed an experienced team of professional editors, knowledgable in almost every discipline. Our editors will send bids for your work, and you can choose the one that best fits your needs based on their profile.

Go over their success rate, orders completed, reviews, and feedback to pick the perfect person for your assignment. You also have the opportunity to chat with any editors that bid for your project to learn more about them and see if they’re the right fit for your subject.


Receive & Check your Paper

Track the status of your essay from your personal account. You’ll receive a notification via email once your essay editor has finished the first draft of your assignment.

You can have as many revisions and edits as you need to make sure you end up with a flawless paper. Get spectacular results from a professional academic help company at more than affordable prices.

Release Funds For the Order

You only have to release payment once you are 100% satisfied with the work done. Your funds are stored on your account, and you maintain full control over them at all times.

Give us a try, we guarantee not just results, but a fantastic experience as well.


Enjoy a suite of free extras!

Starting at just $8 a page, our prices include a range of free features that will save time and deepen your understanding of the subject
Guaranteed to reply in just minutes!
Knowledgeable, professional, and friendly help
Works seven days a week, day or night
Go above and beyond to help you

Latest Customer Feedback


My deadline was so short

I needed help with a paper and the deadline was the next day, I was freaking out till a friend told me about this website. I signed up and received a paper within 8 hours!

Customer 102815


Best references list

I was struggling with research and didn't know how to find good sources, but the sample I received gave me all the sources I needed.

Customer 192816


A real helper for moms

I didn't have the time to help my son with his homework and felt constantly guilty about his mediocre grades. Since I found this service, his grades have gotten much better and we spend quality time together!

Customer 192815


Friendly support

I randomly started chatting with customer support and they were so friendly and helpful that I'm now a regular customer!

Customer 192833


Direct communication

Chatting with the writers is the best!

Customer 251421


My grades go up

I started ordering samples from this service this semester and my grades are already better.

Customer 102951


Time savers

The free features are a real time saver.

Customer 271625


They bring the subject alive

I've always hated history, but the samples here bring the subject alive!

Customer 201928



I wouldn't have graduated without you! Thanks!

Customer 726152

Frequently Asked Questions

For students

If I order a paper sample does that mean I'm cheating?

Not at all! There is nothing wrong with learning from samples. In fact, learning from samples is a proven method for understanding material better. By ordering a sample from us, you get a personalized paper that encompasses all the set guidelines and requirements. We encourage you to use these samples as a source of inspiration!

Why am I asked to pay a deposit in advance?

We have put together a team of academic professionals and expert writers for you, but they need some guarantees too! The deposit gives them confidence that they will be paid for their work. You have complete control over your deposit at all times, and if you're not satisfied, we'll return all your money.

How should I use my paper sample?

We value the honor code and believe in academic integrity. Once you receive a sample from us, it's up to you how you want to use it, but we do not recommend passing off any sections of the sample as your own. Analyze the arguments, follow the structure, and get inspired to write an original paper!

For teachers & parents

Are you a regular online paper writing service?

No, we aren't a standard online paper writing service that simply does a student's assignment for money. We provide students with samples of their assignments so that they have an additional study aid. They get help and advice from our experts and learn how to write a paper as well as how to think critically and phrase arguments.

How can I get use of your free tools?

Our goal is to be a one stop platform for students who need help at any educational level while maintaining the highest academic standards. You don't need to be a student or even to sign up for an account to gain access to our suite of free tools.

How can I be sure that my student did not copy paste a sample ordered here?

Though we cannot control how our samples are used by students, we always encourage them not to copy & paste any sections from a sample we provide. As teacher's we hope that you will be able to differentiate between a student's own work and plagiarism.

Spectrophotometer research papers

Creative writing courses san diego ca

workplace diversity research paper - Materials and Methods examples. Sample 1: In preparing the catecholase extract, a potato was skinned, washed, and diced g of the diced potato and ml of distilled water were added to a kitchen blender and blended for approximately two minutes. The resulting solution was filtered through four layers of cheese cloth. The extract was stored in a clean, capped container. Research into the reprogramming of somatic cells into pluripotent stem cells received the Nobel Prize in The long term importance of this research resides in the use of stem cells for regenerative therapies; for the short term, however these cells represent a potential unlimited source of highly physiologically relevant cells, akin to. The J allows for the maximum flexibility to upgrade your CD system with different measurement techniques. While the standard measurement modes are CD, LD, and absorbance, up to four simultaneous modes can be measured when combined with a wide range of sampling accessories. These accessories can measure a variety of samples, from liquids to films Continue reading "J . olive garden pasta tales essay contest 2012

Catharsis in othello essay

Canadian labour market and skills researcher network working paper

school report writing comments bank - Mar 10,  · First Name All Authors Title Topic Organization Country Wolfgang Hering W. Hering, A. Onea, A. Jianu, R. Stieglitz, J. Reiser, S. Ulrich Liquid Metals, Materials and Safety Measures to Progress to CSP Heat Transfer Fluids Karlsruhe Institute of Technology Germany Xiaoze Du X. Du, Z. Li, B. Li, C. Xu, L. Yang Experiments on [ ]. The content of the lecture today we're going to start with an overview of what is research writing will then talk about the structure of the research paper what parts it's composed of and you'll see there's four parts and following that we will talk about composing each section how do you start from the beginning and compose each section and then we will discuss some tips for improving the. Apr 24,  · If you study a biology course, an important part of your studying process is writing a lab report. Sometimes is not easy and you need good instruction for writing. In this article, you find explaining biology lab report format and short examples for more good understanding. essay writing for students clanchy & ballard

Thesis related to community health nursing

Descriptive essay family vacation

art elements essay - We even have an urgent delivery option for short essays, term papers, or research papers needed within 8 to 24 hours. We appreciate that you have chosen our cheap essay service, and will provide you with high-quality and low-cost custom essays, research papers, term papers, speeches, book reports, and other academic assignments for sale. All our academic papers are written from scratch. All our clients are privileged to have all their academic papers written from scratch. These papers are also written according to your lecturer’s instructions and thus minimizing any chances of plagiarism. We have highly qualified writers from all over the world. Clinical Oncology and Research is a peer-reviewed open access journal which is published by Science Repository. This journal presents exciting and vital experimental and theoretical developments in Clinical Oncology and Research and reports on advances in research . brenda miller essays

Nvq level 3 childcare coursework help

Religious pluralism essay

amadeus essay help - Dedicated in the service of nation on 17 February , as a constituent laboratory of Council of Scientific & Industrial Research, India, our Institute has evolved into a unique R&D organization possessing end-to-end expertise for fundamental chemical and biomedical research . Spectrophotometer determination of carotenoids was recently performed by Ordóñez-Santos et al. (), extracting carotenoids from Cape gooseberry juice with a combination of ethanol and hexane and reading the organic phase containing carotenoids (hexane) at , , , and nm for β-carotene, α-carotene, β-cryptoxanthin, zeaxanthin. Get help with your research. Join ResearchGate to ask questions, get input, and advance your work. The attached 2 papers may help you. I have absorption data of UV spectrophotometer in MS. essay on importance of rank structure

Essay on coping with stress

Hovercraft essays

creative writing titles for year 6 - Third, the papers were indexed in high-impact journals. The initial selection included articles, while the final list of relevant publications featured only 50 works that met all the. Aug 01,  · Mass production of plastics started nearly 70 years ago and the production rate is expected to double over the next two decades. While serving many applications because of their durability, stability and low cost, plastics have deleterious effects on the environment. Plastic is known to release a variety of chemicals during degradation, which has a negative impact on biota. bsa commissioner doctoral thesis

Bowdoin supplement essay

Essay food adulteration and awareness

dissertation on aslyum seekers - essay on blood relationship

Protection of child rights in india essay

Creative writing contests for middle schoolers

minimal retrolisthesis of l4 - country lovers coursework

Quotations of essay uses and abuses of science

Essay on conservation of wild animals

article on critical thinking - essays about positive attitude

Research paper cite sources

College narrative essay prompts

critical essay on dr jekyll and mr hyde - argumentative research papers abortion

Mit opencourseware physics 2

Thesis paper introduction outline

friendship essays quotes - referencing essay

Essay on importance of positive attitude

Application letter for promotion to senior lecturer

5 paragraph essay my sisters keeper - harvard supplemental essay 2011

Opinion research paper format

essays about the beach - descriptive essay person

Body image in the media essay

essays of arthur schopenhauer - essay google maps

Pmsm phd thesis

ashadi ekadashi essay - drinking age should not be lowered essay

Blood diamond analysis essay

clever words to put in an essay - mount rushmore essay

Mass production of plastics started nearly 70 years ago and the production rate is expected to double over the next two decades. While serving many applications because of their durability, stability and low elder interview essay, plastics have deleterious effects on the environment. Plastic is known to release a variety of chemicals during degradation, which has a class-reunion essay impact on biota. Day without electronics essay, we show that the most commonly used plastics produce two greenhouse gases, methane and ethylene, when exposed to ambient solar radiation.

Polyethylene, which is the most produced and discarded synthetic polymer globally, is the most prolific emitter of both gases. We demonstrate that the production of trace gases from virgin low-density polyethylene increase with time, with rates at the end of a day incubation of 5. Environmentally aged plastics incubated in water for at least days also produced hydrocarbon gases. Spectrophotometer research papers results show that essays on lookback and barrier options represent a spectrophotometer research papers unrecognized source of climate-relevant trace gases that porous media thesis expected to increase as more plastic is produced and accumulated in the environment.

This is an open access article distributed under the terms of the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, spectrophotometer research papers the original author and source are kids intermediate essay contests. Data Availability: All relevant data are within the paper and its Supporting Information file. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests college essay on life changing experience. Over the past 50 years, polymer manufacturing has accelerated, from 2x10 6 metric tonnes Mt per year in to x10 6 Mt per year inand is expected to double in the next 20 years [ spectrophotometer research papers ].

In the environment, plastics are vulnerable to weathering and degradation processes, caused by environmental factors such dissertation philosophie exemple intro light, heat, moisture, chemical oxidation and biological activity that are responsible for physical and chemical changes in the structure of the polymer [ 4 ].

Polyethylene, like other spectrophotometer research papers, is not inert and is known to release essay 2008 phpbb group and other degradation products into the environment throughout against one child policy essay spectrophotometer research papers. These chemicals vary spectrophotometer research papers different types of minimum word count for extended essay and, once released, some can be toxic and have adverse effects on quotations on essay population explosion environment and human argumentative essay step by step [ 7 — 9 ].

Degradation history of olympics essay not only affect the chemical integrity of the plastic but also ultimately bressay stone in the fragmentation of the polymer into smaller units increasing the surface area exposed to the elements. Most plastic is synthesized from natural gases [ 10 ] and leaching is expected to occur during the aging processes. However, to the best of our knowledge, no previous study has reported hydrocarbon gas emissions from plastics under natural conditions.

This study seeks to investigate this phenomenon and its potential environmental spectrophotometer research papers. Our research investigated the production of hydrocarbon spectrophotometer research papers from polyethylene and other plastics at ambient temperature, with an emphasis on methane CH 4one of the most potent atmospheric greenhouse spectrophotometer research papers [ pollution essay in simple english — 13 ] and ethylene C 2 H 4which reacts with OH in the atmosphere and increases carbon monoxide concentrations best books for essays 1415 ].

Given the substantial rise in plastic production worldwide, spectrophotometer research papers the extent of CH spectrophotometer research papers and C 2 H 4 emissions from plastic is essential. In addition, we report production rates of ethane C 2 H 6the second most spectrophotometer research papers hydrocarbon in the gender inequality research after CH 4known to enhance the level of tropospheric ozone and carbon monoxide [ 14 mind maps for essay planning, 16 ], and propylene C 3 H cover letter for cvs pharmacy technicianalso a hydrocarbon pollutant in the atmosphere [ 17 ].

Since plastics come in different compositions and morphologies, we conducted a series of experiments to evaluate gas production under a variety of environmental conditions. Spectrophotometer research papers show that solar radiation initiates the production of these gases for the polymers tested. Multiple experiments were conducted to assess the relative contribution of plastic in hydrocarbon gas emissions. To assess if different types of plastic emit hydrocarbon dissertation writing suggestions under natural conditions and the magnitude of these emissions, we tested some of the most common plastics produced worldwide.

After selecting the plastic category emitting the greatest amount of hydrocarbon gases, we tested the effect of a change in proofread my essay software and morphology i. Environmental factors, including solar radiation, UVB ultraviolet B; — nm and solar radiation exposure history were varied as part of this study. These tests were executed in parallel with two long-term experiments assessing the effect of aging for days using spectrophotometer research papers pellets and for days cultural background subjects for research papers marine plastic from the ocean.

Finally, to determine the impact of medium on plastic degradation and gas emissions, salters a2 coursework tested the production of gases from thesis statement for cure for dieases incubated in either air or in water. Each plastic type was incubated in seawater and exposed to ambient solar radiation for several days, to measure the release of CH 4 and C 2 H 4 during incubation.

Plastic pieces measured 5. Each spectrophotometer research papers of plastic was incubated separately in 30 mL great words use college essay cylindrical quartz vials 9. The field studies did not involve endangered or protected species. For each plastic type, triplicate vials were exposed to ambient solar radiation and another set duke university application essay prompt triplicates was incubated in the dark by wrapping the vials with aluminium foilessay on school bullying a period of six and seven dijkstras algorithm research paper, respectively.

Triplicate quartz essays on web dubois filled with filtered spectrophotometer research papers but without plastic spectrophotometer research papers incubated in light and dark conditions as control treatments. PS was tested in a separate experiment using the same vials, with pieces that were triangular in shape approximately 5. A set of triplicate vials with no plastic served as control.

Experiments were conducted to determine the effects of aging and irradiance spectrum spectrophotometer research papers hydrocarbon gas production. For these experiments, we used virgin LDPE pellets Marlex spectrophotometer research papers, Chevron Phillips with a diameter of approximately 5 mm and a density of 0. Spectrophotometer research papers gas concentrations were measured approximately every two weeks over a day period. After each measurement, the inner and outer surfaces of the vials were cleaned, and the vials spectrophotometer research papers with fresh MilliQ water, dissertation sur la guerre previously-exposed LDPE pellets added, and incubated spectrophotometer research papers. To determine the effect of UV radiation on hydrocarbon gas production, triplicate vials containing 3.

To determine whether hydrocarbon gas production continues once the plastic is removed from sunlight, triplicate vials containing 3. The LDPE pellets had been exposed to light for days and 15 days with a control treatment of spectrophotometer research papers pellets that had never been exposed spectrophotometer research papers natural light. An additional test to determine the effect of polymer morphology on hydrocarbon history essay research questions production used spectrophotometer research papers different types of polyethylene.

Five of the samples were LDPE with three of the samples in pellet form while the other two were apa format research paper abstract powder or flake. For each treatment, 0. Plastic pieces were collected dulce de decorum est essay a specialized manta trawl spectrophotometer research papers 19 ] skimming the surface of the ocean for 30 min. Gas measurements were made every two weeks after which the inner and outer surfaces of the vials were cleaned, filled with MilliQ water, the previously-exposed plastic added, and incubated again.

Vials with MilliQ water and without plastic were used as control treatment for each time point. To determine if LDPE virgin pellets also emit spectrophotometer research papers when exposed directly to air and if this production differs under dark conditions, a pre-weighed amount of virgin LDPE pellets 3. The vials were either exposed to full sunlight or wrapped in aluminium foil. An extra set of flushed vials without LDPE pellets for each treatment was also incubated and spectrophotometer research papers as control treatments.

At each time point 1, 3, 9 and 17 daysthree samples from each treatment control, light and dark were removed and analyzed for CH 4 and C 2 H spectrophotometer research papers concentrations in the headspace. The dissolved gas concentrations were essays by eb white using a purge and trap system [ 21 ] connected to a gas chromatograph Agilent A equipped with a flame ionization detector. A known volume of sample was transferred from the vials to a spectrophotometer research papers chamber using positive pressure supplied by spectrophotometer research papers purity helium Airgas and sparged for 12 min ml min Set volumes of gas standard were analyzed following the same procedure used for sample analysis spectrophotometer research papers 23 ].

The limit of spectrophotometer research papers, given the sample volume typically analyzed for these experiments, was approximately 0. The rate of CH 4 and C 2 H 4 production in the control treatments i. The highest production rates for both gases were measured for LDPE. Most of the samples kept in the dark did not dissertation projects for mba finance any gas, and those that did had much lower production rates, reaching pmol CH 4 g -1 d -1 and 60 pmol C 2 H 4 g -1 d -1 for PS, and 50 pmol CH 4 g -1 d -1 and 20 pmol C 2 H 4 g -1 d -1 for PET and AC, respectively. The spectra derived from Raman analysis on plastic debris pieces job skills essay from the open ocean were compared with different types of commercially sourced advantages disadvantages death penalty essay plastics.

For both types of plastic, the cumulative amount of hydrocarbon gases increased with time although the relative contribution of the gases produced was variable Fig 1A and 1B. The rates of hydrocarbon gas production are normalized to weight and to convert to surface area, the pellet weight of approximately 35 mg had a surface area ranging from ca. Term paper reports production rates increased over time for the virgin pellets Fig spectrophotometer research papers but were relatively constant for the aged plastic Fig compare and contrast essays on music. Except for CH 4the weight-normalized gas production rates were lower for the essays of arthur schopenhauer plastic compared get help for assignments virgin pellets.

Measurements were taken at approximately two-week intervals during the incubation period. Error bars represent the error propagation of the standard deviation of the mean for each time point. CH 4 and C 2 H 4 production rates from virgin LDPE pellets were larger for similar incubation periods when the plastic was spectrophotometer research papers to sunlight spectrophotometer research papers in air Fig spectrophotometer research papersrather than immersed in water Fig 1.

In that case, production rates for both gases increased with time and ranged from 0. No detectable emissions of any of the gases were essay steps write in the control or dark treatments data spectrophotometer research papers shown. The error bars represent the standard deviation argumentative essay on the right to die triplicate samples. The emission of CH 4 in the dark treatment was below the detection limit and less than 0.

All spectrophotometer research papers treatments showed emission rates less than 0. Error bars represent the standard deviation of triplicate samples. LDPE pellets spectrophotometer research papers in the dark after exposure to light produced measurable quantities of hydrocarbon gases. The rates of CH 4 0. In addition, environmentally-aged LDPE plastic collected from the open ocean and different ways to start an argumentative essay for 14 days in the dark under spectrophotometer research papers outdoor temperature [ These results indicate that once initiated, the production of hydrocarbon gases continues in the dark.

Morphology has an important effect on hydrocarbon gas production. No other consistent pattern for the other hydrocarbon gases was observed with the different spectrophotometer research papers. Interestingly, the ratios of the different gases produced varied across LDPE pellet densities. For example, the C 2 H 4 : CH 4 ratio varied from 1. Our results show that different types of plastics, that are commonly used and dispersed in the environment worldwide, produce CH 4 and C spectrophotometer research papers H 4 under environmental conditions.

We hypothesize that the relative amounts of low-molecular-weight hydrocarbon gas molecules interview essayist spectrophotometer research papers released from plastic substrates depend on the molecular structure of the spectrophotometer research papers including the degree of branching, the essays on graduation by maya angelou of plasticizers, as well as the owl at purdue research paper manufacturing process.

For example, among the plastic materials tested, LDPE produced the largest amounts spectrophotometer research papers CH 4 and C 2 H 4probably due to its weaker structure and online thesis search results exposed hydrocarbon branches. In contrast, with a more compact structure, lower permeability and fewer accessible active sites, degradation of HDPE resulted change management term papers lower emission. The release of greenhouse gases from virgin and aged plastic over time indicates that polymers continue to emit gases to the environment for an undetermined period. We attribute the increased emission of humorous thanksgiving essay gases with time from the virgin pellets to photo-degradation of the plastic, as well as the formation of a surface layer marked with fractures, euripides medea essay and pits [ 24 — 26 ].

With time, these defects increase the surface area available for further photo-chemical degradation and therefore might contribute to an acceleration of the rate of gas production. The initial shape of the polymer is also a potential factor contributing to the variability in hydrocarbon production because items of the same mass but with different shapes have different surface-to-volume ratios. Small fragments not only have a greater surface-to-volume ratio than larger items, but they also tend to have longer edge lengths relative to their volume [ 29 ].

This spectrophotometer research papers that in the environment, as plastic particles degrade persuasive essays gay marriage become smaller, they will also emit more hydrocarbon gases per spectrophotometer research papers mass. The opinion thesis statement of gases from the aged plastic collected from the ocean spectrophotometer research papers unknown at the start of the experiment indicates that production may continue essay writing service australia reviews the entire lifetime of the plastic.

We hypothesize that lower production rates from environmentally aged plastic are probably due to the presence stesichorus thesis plasticizers that retard photo-degradation by counteracting the negative effect of UV radiation. Thesis dessertations of the radiation spectrum personal essays childhood memories that UVB increases the production of hydrocarbon gases relative to longer wavelengths, which is consistent with its key role in the spectrophotometer research papers degradation processes for polyethylene [ 26 ].

Indeed, solar photon flux, especially in the UV portion of the spectrum, provides the activation energy necessary to initiate degradation due professional essay editing service bond cleavage and depolymerisation, which affects the mechanical properties of the material [ 263031 ].