Spelling suggestions: "subject:"eggshell."" "subject:"shells.""
11 |
Surface Separation Equilibria and Dynamics of Cationic Dye Loaded Onto Citric Acid and Sodium Hydroxide Treated EggshellsAdeniji, Elisha A., Abodunrin, Temitope O., Ogunnupebi, Temitope A., Koiki, Babatunde A., Olatunde, Abimbola M., Omorogie, Martins O. 01 January 2019 (has links)
This research enthusiastically highlights the bio-adsorption of methylene blue (MB) by local, poultry, NaOH and citric acid modified ubiquitous eggshell (LES, NLES, CLES, PES, NPES and CPES) adsorbents. The microstructures of these adsorbents indicated that they had some surface functional moieties that were responsible for the adsorption of MB. The Langmuir isotherm and PSO model best fit the experiment data. The largest Langmuir monolayer adsorption capacity qmax, was 242.47mg/g, with the largest MB initial concentration of 400mg/L. This was a clear indication and a confirmation that MB adsorption by the powdered eggshells was chemisorptive. Moreover, the values of F $F$, the thickness of the boundary layer/film were >0, showing that the rate limiting step for the adsorption process was controlled by more than one diffusion mechanism. The values of ΔG° for the adsorption of MB by the adsorbents indicated that the adsorption reactions were all non-feasible and non-spontaneous. The values for ΔS° (J/K/mol) for LES, NLES and CPES for the uptake of MB showed decrease in the chaos or degree of randomness of the adsorption reactions, and the reverse was the case for PES, NPES and CLES for the uptake of MB, which showed increase in the chaos or degree of randomness of the adsorption. The adsorption of MB by LES, NLES and CPES gave ΔH°(kJ/mol) values which were indicative of endothermic nature of the adsorption systems, and the reverse was the case for the uptake of MB by PES, NPES and CLES, which was indicative of the exothermic nature of the adsorption systems.
|
12 |
Using eggshell for the development of a quality alternative material to pumice in reducing the surface roughness of heat-cured acrylic resins.Onwubu, Stanley Chibuzor January 2016 (has links)
Submitted in fulfillment of requirements of the degree of Master in Health Sciences: Dental Technology, Durban University of Technology, Durban, South Africa, 2016. / Pumice is used in the polishing of dental appliances to remove surface irregularities. It is usually used in a slurry form that is pumice powder mixed with water. In Nigeria, the increased cost of pumice as a result of its limited supply into the country has encouraged dental technicians to re-use pumice slurry for longer periods than advocated when polishing acrylic dentures, whether new or old dentures which have been worn in the mouth. Consequently, this is likely to increase cross-infection of communicable diseases in the dental technology laboratory. Although materials such as white sand, black sand and porcelnite can be used, literature documents that these materials are less effective in the polishing of acrylic dentures (Areeg 2011). The focus of this study was to use eggshells, a natural waste product, to develop and test the quality of an alternative material to reduce the surface roughness of heat-cured acrylic resins.
A quantitative research paradigm and an experimental research strategy were adopted. The research design included two phases. In phase one of this study, different characterisation techniques such as Brunnae-Emmer Teller (BET); Fourier Transform Infrared Spectroscopy (FTIR); X-ray Diffraction (XRD); Energy Dispersive X-ray Spectroscopy (EDX) and Scanning Electron Microscope (SEM); Transmission Electron Microscopy (TEM); Laser Scattering Particle Size Distribution Analyser (PSA); Thermo-Gravimetric Analysis (TGA); and Induction-Coupling-Optical Emission Spectroscopy (ICP-OES) were used to assess the suitability of the new abrasive material (NAM). In addition, the level of microbial contamination of the NAM was assessed in line with the specified microbial limits for cosmetic products. In contrast, phase two investigated the product-based quality of the NAM as an abrasive material for removable dental appliances. There were two sample groups, that is, the NAM (test group) and Pumice (control), and each sample group had 50 PMMA acrylic specimens. The surface roughness (Ra) was measured using a Talysurf profilometer. An Independent Tukey test was used to analyse the Ra values (p=0.05). A Scanning Electron Microscope (SEM) and Optical Microscope (OEM) were further used to support the results of the profilometer in terms of the quality of surface finish and polish. Validity of the study was achieved following the ISO 20795-1 (2013) methods of preparation and fabrication of the acrylic specimens. The reliability was determined via reproducibility and repeatability of tests.
The BET analysis showed that the NAM is predominantly a mesoporous powder. The FTIR and XRD analyses confirmed that the NAM is pure calcite with unique water absorbing characteristics, and is free of bacteria. The EDX and ICP-OES analyses revealed calcium, oxygen and carbon as the major elemental composition of the NAM. The SEM and TEM images revealed irregular shaped particles in the NAM. The PSA analysis of the particle distribution showed the NAM to be superfine (50nm to 0.3µm) and medium (44µm powder), respectively. The TGA analysis revealed a high-grade carbonate product in the NAM (>66.0 mass% of calcium carbonates). In addition, and in terms of in the qualities of the NAM in reducing the surface roughness of PMMA resins, the test group and the control group produced Ra values that were significant different (p<0.0001). The SEM and OEM analyses further confirmed the differences in the surfaces between the polished sample groups at different magnifications. Overall, the control showed the highest mean average (0.1056±0.03688µm), whereas the test group had the lowest Ra values (0.0476±0.01379).
The lowest Ra values measured with the test group indicated that the NAM improves the surface smoothness of PMMA acrylic specimens. Notably, this study conclusively showed that the NAM effectively reduces the surface roughness to below the threshold limit value of 0.2µm. Significantly, and in associating the Ra values to the threshold limit value of 0.2µm, the NAM produced better results than pumice. Hence the use of the NAM as a polishing material for acrylic dentures is highly recommended. Finally and in line the NAM being a suitable alternative to pumice as it effectively reduces the surface roughness of PMMA specimens, future investigation into the use of eggshell nanoparticles to develop dental prophylaxes will be encouraged. / M
|
13 |
Effects of dietary calcium, phytoestrogen rich diets and estrogen on intestinal calcium transport proteins, egg and eggshell quality in maturing layer hens / Ali Asghar Saki.Saki, Ali Asghar January 1998 (has links)
Corrigenda inserted behind title page. / Copies of author's previously published articles inserted at end. / Includes bibliographical references (leaves 193-210). / xxii, 210 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates whether estrogen modulates the proteins associated with calcium transport (eg calcium binding protein, calbindin D28k) in the intestinal tissue during sexual maturation of laying hens. Studies the temporal and spatial expression of estrogen receptors (ER) and calcium binding protein in jejunal tissue. Findings indicated the potential of estrogen to induce calbindin D28K in the intestinal tissue, from which it can be concluded that estrogen may increase calcium absorption and consequently calcium retention. Shows that the amount of estrogen normally present in the reproductive system is sufficient for the normal capacity of egg and eggshell production. Egg production and shell quality are significantly reduced by phytoestrogen. It is recommended that the concentration of phytoestrogen in poultry diets be investigated in more detail as it may act as an anti-nutritive factor and affect metabolism and productivity. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1999
|
14 |
Effect of local changes to shell permeability on the gas exchange of the avian embryo / by Kerstin Wagner.Wagner, Kerstin January 2000 (has links)
Bibliography: leaves 148-166. / xi, 166 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The chicken embryo's ability to match the perfusion of its chorioallantoic membrane to regional differences in shell conductance was investigated. / Thesis (Ph.D.)--Adelaide University, Dept. of Environmental Biology, 2001
|
15 |
A study of biodiesel production from waste vegetable oil using eggshell ash as a heterogeneous catalystTshizanga, Ngoya January 2015 (has links)
Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology. / While biodiesel has the potential to resolve the energy crisis, its production is hampered by both feedstock and catalyst availability. The aim of this current study is to investigate the production of biodiesel from waste vegetable oil (WVO) as feedstock under heterogeneous catalysis, mediated by calcined eggshell ash. WVO, characterised by 9% free fatty acid (FFA) and 0.17wt% water content, was employed as feedstock in the biodiesel production via transesterification reaction. The composition of WVO was determined using Gas chromatography (GC) analysis. The eggshell was washed with distilled water to remove impurities, dried in an oven at 105°C, and then crushed into fine particle of 75μm, and finally, calcined in a muffle furnace at 800°C. The chemical properties of the catalyst were assessed as follows: 1) using X-ray diffraction (XRD) to determine the major component phase of the element; 2) using X-ray fluorescent (XRF) to determine the elemental composition of the eggshell ash; 3) using Brunauer Emmet Teller (BET) to define the structure, the surface area, pore volume and pore diameter of the eggshell ash; and 4) using SEM to show the morphology structure of the element. The XRD analysis performed on eggshell ash showed 86% CaO as a major component in the catalyst; the remaining 14% was composed of MgO, SiO2, SO3, P2O5, Na2O, Al2O3, K2O and Fe2O3, as obtained from XRF. The BET result of the catalyst prepared was characterised by large pore diameter (91.2 Å) and high surface area (30.7m2/g), allowing reactants to diffuse easily into the interior of the catalyst used
|
16 |
En hårdkokt historia : En studie av äggskalfynd från vikingatida gravkontext med särskilt fokus på Uppland och Gotland / Hard-Boiled Mysteries : A study of archaeological eggshell finds within Viking Age grave contexts in Uppland and Gotland provincesJelicic, Anna January 2017 (has links)
This thesis examines archaeological eggshell finds from cremation graves in the Swedish province of Uppland as well as inhumation graves from the island of Gotland. All graves are dated to the Viking Age, however, the chronology varies by the region, with the period´s ending placed around year 1050 AD in Uppland and around year 1150 AD at the island of Gotland. An attempt is made to create a list of all known cases of egg depositions in graves during the period of interest, and to subsequently analyse them all in order to get a better understanding of this practice. The comparative analysis of the artefact assemblages within the graves and grave constructions is undertaken in order to identify possible regularities in how and when the egg was used within the ritual sequence. Although notable regional variations and differences in Viking Age burial customs are known to exist between the two investigated regions, and artefacts deposited within the graves are adapted to regional conditions, it is possible, amongst other things, to observe similarities in the timing of egg deposition. By understanding the funeral as a rite of passage that signified the transition between the states of life and death, and with the final goal of achieving the distinction between the world of the living and the realm of deceased ancestors, it is possible to better comprehend the funeral rituals and their archaeological remains – in this case avian eggshells. By applying van Gennep's rites of passage tripartite structure, involving separation, liminality, and incorporation, it is concluded that eggs, as we see them in the archaeological material presented in this study, are used in the last stage of this model. This is the part of the process where the main goal is reintegration of those who participated in ritual into a new social order. It is thus proposed here that eggs might be seen as hierophanies: profane, everyday objects that have manifested into something sacred and who are clearly understood as such to those involved in burial but not necessary to outsiders: as symbols for fertility, regeneration, rebirth and transformation.
|
17 |
Oological Record of Dinosaurs in South-Central Pyrenees (SW Europe): Parataxonomy, diversity and biostratigraphical implicationsGarcia Sellés, Albert 22 June 2012 (has links)
Southern Pyrenees has provided an abundant fossil record of dinosaur eggs and eggshells. Historically, the oofamily Megaloolithidae has shown its predominance over any other group of fossil eggs in this region. In addition, this oofamily is world-wide distributed being represented by, at least, four oogenus and 20 oospeices. Considering that the eggshell is a high stable structure, this number of Megaloolithus‘s oospecies is too high for such a relatively short time-interval (Campanian to Maastrichtian; less than 7 My). The structural characters used to define these oospecies are critically revised. As a consequence, three structural groups have been identified, and only ten oospecies have been considered valid. Four of those oospecies have been recognized in Southern Pyrenees: M. aureliensis, M. sirugei, M. mamillare and M. baghensis.
The oogenus Cairanoolithus, historically included in Megaloolithidae oofamily, is reevaluated. All evidences suggest that this type of fossil egg is, definitively, different from any other Megaloolithus. Consequently, a new oofamily is erected (Cairanoolithidae oofam. nov), which emphasizes the singularity of cairanoolithid eggs. Phylogenetical analysis also suggests that the eggs of Cairanoolithidae oofam. nov. could be laid by ornithischian dinosaurs.
New oological material is described here, including the first spheroolithid oospecies (Spheroolithus oosp. nov.) from the Upper Cretaceous of Europe. Several oospecies of Prismatoolithus (Prismatoolithus oosp. nov, Prismatoolithus cf. levis, Prismatoolithus oosp. indet.) and few eggshells of ratite-morphotype (cf. Ageroolithus fontllonguensis) have been identified. In addition, the great number of specimens attributed to Pseudogeckoolithus oogenus allows re-describing and re-assigning this ootaxon to Mesozoic lizards.
The space-temporal variation of the oological diversity in the Southern Pyrenees could be a consequence of environmental changes during the end-Cretaceous or even due to preferences in the nesting-site of each group of dinosaurs.
Finally, biostratigraphical studies based on the successions of megaloolithid oospecies have been performed in Coll de Nargó and Àger-Tremp basins, and the European Megaloolithus succession has been updated. As a result, three oozonones have been described: M. aureliensis + Cairanoolithus oozone dates the Late Campanian, M. siruguei oozone the Early Maastrichtian and M. mamillare + M. baghensis oozone the Late Maastrichtian.
|
18 |
An investigation into the efficacy of eggshells as a low cost adsorbent for the removal of potentially toxic inorganic elements from aqueous solutionsMashangwa, Terence Dambudzo 09 1900 (has links)
Excessive release of metals and metalloids into the environment is a major global environmental concern and there is need for environmentally friendly and cost effective methods for their removal. The present study investigated the adsorptive removal of zinc, lead, copper and nickel ions from synthetic aqueous solutions and various metals from three acid mine drainage (AMD) sites using chicken eggshells. Process parameters including the initial metal concentration were evaluated and the optimum conditions obtained were pH 7, adsorbent dose of 7 g and contact time of 360 minutes (for the removal of 100ppm metal ions). Under these conditions the percentage adsorptions were; 97% for lead, 95% for copper, 94% for nickel and 80% for zinc. Aluminium, iron, potassium, nickel and zinc ions all had percentage adsorptions above 75% in AMD Sample 1. Potassium had a 98.78% adsorption while magnesium, strontium and zinc had 72.33; 68.75 and 53.07% adsorption respectively in Sample 2. Arsenic, chromium, copper, iron, antimony and tellurium ions were above 75% for Sample 3. The study demonstrated the efficacy of chicken eggshells and presents it as a viable low-cost adsorbent for bioremediation. / Environmental Science / M. Sc. (Environmental Science)
|
19 |
Implementing Biomimicry Thinking from fundamental R&D to creating nature-aligned organizationsFecheyr Lippens, Daphne 29 September 2017 (has links)
No description available.
|
20 |
Äggskal,avfall eller resurs? : En materialdriven designprocessSofee, Sofidar January 2021 (has links)
Egg consumption in Sweden is very high, which means a lot of egg shells are thrown out. For example the average swede consumes about 350 eggs every year. In this thesis I have investigated how eggshells can be applied in new areas as a resource, and I want to inspire the reader and encourage them to rethink what is called waste. Is it really waste or a possible resource? The work began with literature search, interviews and a survey to understand people's views on eggshells. I have concluded that not a lot of people know what eggshells are made of, and what they are used for. In a literature search I came across many scientific articles on eggshells. According to King’ori (2011) eggshells are used as fertilizers, used in medicine, cosmetic surgery, and dental care, calcium supplements, in the food industry and in crafts. When eggshell is thrown as food waste it creates problems in recycling stations, the eggshell is like sediment and lies at the bottom of tanks and pipes. The recycling staff have to perform additional work when cleaning tanks and pipes as eggshells are like sediment and lay at the bottom. The staff have to manually shoot out eggshells with many other useful materials that could have been digested and become biogas. This is an exploratory thesis where I investigate the material eggshell through a material-driven design process to find new sustainable uses. I follow the material-driven design process method by Karana et al.( 2015) plus my own added steps during the process. Material driven design process is a process where designers use a material to find the attributes of the material. These are then presented in new contexts or already existing contexts, this means that the material on the existing product can be replaced. This differs from traditional design, where the material is chosen based on wanted attributes. This report will give you an understanding of the material-driven design process-method and how I have carried out a material-driven design process, to develop different material properties of eggshells. The report ends with a concluding discussion and presents new eggshell-based materials that I have produced in the form of a demonstrator. It is a book which has two different materials, a hard material and a paper material which are combined and put together with a steel thread. I will also share my knowledge about eggshells and what potential it has in the future.
|
Page generated in 0.0347 seconds