The fiber suspension to papermaking consists of a large number of components which differ from each other in various respects such as size, shape, surface area, surface roughness and electrical charge (Figure 1). The suspension of fibers and fine contains mineral filler and additives which aim at improving the process of papermaking and their properties. The fibrous material when dispersed in aqueous medium develops surface charge due to the presence of ionizable functional groups such as the hydroxyl and carbonyl. Which results in the inefficiency in the retention of particles of colloidal nature (such as fines and fillers) [10, 11, 14]. The cellulosic fibers normally carry a negative charge when suspended in water due to the presence of ionisable …show more content…
The zeta potential represents the electrostatic charge density induced near the surface of a particle by the action of ions and polymers in suspension. The magnitude and sign of the charge is derived from the measurement of particle motion applied in an electromagnetic field. Since these movements could be strong or weak and depends on the composition of the surface of the particles may occur zeta potential distributions (since not all particles share the same charge). This occurs when more than one type of material is present in the solution (mineral filler and fines) and when it has a high mechanical shearing after mixing. Thus, both the average of zeta potential as the shape of the distribution is important …show more content…
The global retention is the ratio between the total material (fibers, fillers, additives) that is being fed in the machine, and that is getting trapped in the dry sheet. This retention further includes the step of forming the stage of recovery of the fibers outside the machine, usually a flotation stage. While retaining first step is the ratio between the total material fed into the input box and what is retained on the screen. The first pass retention can also be measured or expressed in only one of the components of the mass, as the first step of retaining of fibers, fines or
An error that could have been present during the lab includes not letting the zinc react completely with the chloride ions by removing the penny too early from the solution. For instance, the percent error of this lab was 45.6%, which was determined by the subtraction of the theoretical percent of Cu 2.5% and the experimental percent of Cu 3.64% and dividing by the theoretical percent of Cu 2.5%. This experiment showed how reactants react with one another in a solution to drive a chemical reaction and the products that result from the
While the solution dissolved, 50 mL of distilled water was added to a 150 mL beaker and heated on the hot plate. When the solution started to boil 2.65 grams of Na2SiO3*5H2O was added to the beaker with a stir bar and heated to a gentle boil. When both solutions began to boil, the sodium silicate solution was slowly added to the sodium aluminate. The solution was kept at 900C for 60 minutes and stirred with stir bar. After 60 minutes, the zeolite solution was cooled for 5 minutes and for the magnetized zeolite , 0.78 grams of FeCl3 and 0.39 grams of FeSO4*7H2O was added to the flask and stirred until the iron parts dissolved.
Pedophile in Penn State The general argument made by Maia Szalavitz in her work, “Bystander Psychology: Why Some Witnesses to Crime Do Nothing”, is that it is wrong when people view crime, and they do not take action. More specifically, Szalavitz argues that people tend to keep quiet for each other as a conglomerate. She writes, ”Mike Mcqueary… witnessed child rape firsthand in 2002...
William G. Tapply is an American legal mystery writer best known for writing the Brady Coyne Mystery series. William was born in Waltham, Massachusetts, before his family moved to Lexington. He lived with his mother Muriel and his father H.G Tapply that used to write a weekly column for Field and Stream. He went to Lexington High School and in 1958 enrolled at Amherst College and then proceeded to Harvard from where he graduated with a Master’s in Education. Over the course of 25 years, the master has published more than 40 novels in mystery and fly-fishing one of his favorite pastime.
Only when the material has an accounting transaction returning it to the proper location in the warehouse, can the material be delivered once again to the assembly line. This data is important to understand because there could be several reasons influencing why the raw materials sent are not being received into the appropriate location. One reason could be the lack of manpower. Other reasons may include simply not following the process or parts being damaged during internal transportation through the manufacturing
Therefore to get rid of these, coagulants and flocculants would need be used to separate them from the
INTRODUCTION A gas chromatograph (GC) can be utilized to analyze the contents of a sample quantitatively or in certain circumstances also qualitatively. In the case of preparative chromatography, a pure compound can be extracted from a mixture. The principle of gas chromatography can be explained as following: A micro syringe is used to inject a known volume of vaporous or liquid analyte into the head or entrance of a column whereby a stream of an inert gas acts a carrier (mobile phase). The column acts as a separator of individual or chemically similar components.
In the story "Saying Goodbye to Yang," written by Alexander Weinstein, and the story "St. Lucy 's Home for Girls Raised by Wolves," written by Karen Russell, there are several ways these stories could be seen as humorous or funny/not funny. Each story that we have read is unique in that they each had some sense of humor about them, whether it be witty humor, dry humor, or maybe even the funny/not funny kind of humor. Different types of humor can be interpreted from each of the stories we have read this semester. Yes, these stories can be seen as a joke but there are serious ideas about them. Each story undoubtedly has important concepts intertwined into them.
Medieval society often put forth the idea that men were superior to women in intellect. Abelard writes, “the weaker sex needs the help of the stronger, so much so…that the man must always be over the woman…” (Abelard 39). This ideology of male superiority is clearly depicted in the wide difference between occupations made available to Abelard and Heloise. Although Abelard chose a life of a scholar and philosopher, he had the option to choose from a wide variety of occupations, ranging anywhere from a merchant to a priest. All of the professions available to men were those that put them in dominant positions over the women in society.
If the consistency or integrity of the membrane is damaged the elements stored in
Critical Analysis “Comment Wang-Fô fut sauvé” by Marguerite Yourcenar The text that I have decided to study is “Comment Wang-Fô fut sauvé” by Marguerite Yourcenar. The extract is located after the first paragraph at the beginning of the story. We are introduced to the characters Ling, Ling’s wife and Wang-Fô .
Wislawa Szymborska’s Perception on Human’s Place in the Universe “Microcosmos”, by Wislawa Szymborska, explains how understanding bacteria expanded human’s understanding of the universe. Throughout the poem, she draws comparison between how small humans are in the vastness of the universe, and how bacteria are so small compared to humans. Szymborska depicts human existence as insignificant when compared to the massive scale of the universe in her poem, “Microcosmos”. The title, “Microcosmos”, is itself an oxymoron which describes how learning about bacteria enlarged human’s understanding of their small place in the universe. The prefix “micro” denotes smallness, whereas the root “cosmos” refers to an entire solar system, much larger than human civilization.
(Molarity)(Volume)(Molar mass) The pellets were dissolved thoroughly then was used in filling up the 100 mL volumetric flask. The solution was mixed well
A small amount of sand was added after the layer of cotton. After that, a layer of silica filled almost 1/3 of the column. Finally, another small amount of sand was added just above the silica. The column was given a little tap with an aspirator to make the silica more compact. Figure 2.
This potential can be obtained by Goldman-Hodgkin-Katz model. It was used to calculate the membrane potential when more than one channels were present in the plasma membrane of the cell, and open at the same time. It majorly depends on the permeability of membranes in use. Permeability refers to the ease in which ions can pass through membranes to reach the opposite side. The ions can never reach their equilibrium potentials because three ions are contributing to the membrane potential.