Resumo: Foi avaliado a morfologia de preparos cavitários realizados com o sistema CVDentus® variando-se a potência do ultra-som. As cavidades foram preparadas com a ponta cilíndrica modelo 8.2142, na face vestibular de 15 incisivos bovinos, que foram divididos em 3 grupos: G1 utilizando a potência II do aparelho de ultra-som, G2 a potência III e G3 potência IV do mesmo aparelho, na máquina padronizadora de preparos cavitários durante 1 minuto para cada preparo. Após, os preparos foram seccionados ao meio obtendo-se duas hemi-faces com seus perfis, que foi observado em Lupa Estereoscópica e medidos por meio do programa Leica Qwin. De acordo com os testes estatísticos Kruskal-Wallis e método de Dunn, houve diferença entre a largura e a profundidade dos preparos somente quando comparados às potências III e IV do aparelho de ultrasom, e que a largura da cavidade realizada pela potência III é a mais semelhante ao diâmetro real da ponta. Concluiu-se que a potência III indicada pelo fabricante é de fato a mais apropriada para o uso na clínica diária, pois possibilita a realização de preparos conservadores. / Abstract: This study has evaluated the shape of dental cavities made by CVDentus® system with ultrasound potency variation. The cavities have been made on buccal face of 15 bovine incisors with acylindrical bur (82142). The sample have been divided into three groups: G1, using ultrasound power II; G2, using power II, and G3, using power IV with a standard device. The cavities have been sliced in the middle, allowing thereby the cavity's profile observation with magnifying glasses, and measurement with a Leica Qwin program. The Kruskall-Wallis and Dunn statistical analysis has shown differences between dental cavities shapes when power III and IV were used. However, the cavities who have been made with power III were similar to bur dimension. Therefore, we conclude that the manufacturer indication to use power III is more suitable to clinical use because it allows more conservative cavity preparation. / Orientador: Cyneu Aguiar Pansani / Coorientador: Rita de Cassia Loiola Cordeiro / Banca: Evaldo José Corat / Banca: Silvio Issáo Myaki / Mestre

Made available in DSpace on 2014-10-09T12:32:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:14Z (GMT). No. of bitstreams: 1 00348.pdf: 1090339 bytes, checksum: 89d8cfffeb0919c6046af1f7251d14ae (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Energia Atomica - IEA

Purpose: Describe the perceptions of military registered nurses (RNs) on being prepared to provide nursing care during a deployment. Background: Injuries sustained by war are different from trauma-related injuries occurring within the Unites States. Nurses who provide care during overseas deployment encounter patients with poly-trauma, multiple and highly complex injuries; consequently, this type of nursing requires strong clinical skills beyond what is required in stateside facilities. Additionally, military nurses undergo intense stress related to overseas deployment in a war zone. In fact, military medical providers have one of the highest rates of post-traumatic stress post-deployment. Methods: This project employed a qualitative, case study approach. Semi-structured interviews were conducted with military RNs who worked as nurses during overseas deployment. A script was developed to guide the interview, and further discussion stemmed from participant responses. Recorded interviews were transcribed into text and analyzed for commonalities. Findings: Five military nurses who previously provided nursing care during overseas employment participated in this study. Commonalities included the realization that higher acuity injuries are seen in a deployed setting versus a military stateside hospital. Participants also shared fears that they would not be prepared enough to provide excellent patient care. Another commonality was not knowing how to prepare for an unknown experience. A positive commonality was the sense of pride expressed by the participants regarding their military service and deployment experience. All participants outlined what they had learned and what might have helped them to better prepare for deployment. Unanimously, more clinically relevant training was recommended. The participants shared that they had grown and changed from their deployment experience. Implications: All five participants felt a gap in perceived adequate pre-deployment preparation. They believed they lacked the training to care for the high acuity patients they would encounter during overseas deployment; this shook their self-confidence and caused them to worry about being an effective team member. Military preparedness programs should be expanded to include skills and knowledge relevant to nursing in high acuity, hostile environments. Research looking at the personal preparations, specifically mental and emotional, of military members may be helpful in determining any links between mental resilience and the development of PTSD.

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The energy demands by the industrial world are continuing to rise, while the rate of new oil discoveries is falling. Within the next 30 years, available petroleum supplies are likely to fail to meet the demand, and oil will no longer be able to serve as the world’s major energy source. Coal, being relatively abundant worldwide and potentially adaptable for use in existing plants that have been engineered for petroleum use, can serve as an inexpensive substitute for, or successor to, the more expensive oil fuels in use today. Graphitisable carbon is one of the high-value products from petroleum as its value lies partly in the nuclear industry. Making graphitisable isotropic carbon from well-purified coal is therefore a primary motivation for this study. However, its purity is far too low. Substantial purification is obtained by dissolving the organic part of coal in dimethylformamide with the addition of a little alkali. Results indicated that more than 90% of the organic part of a 10% ash flotation product dissolved in N, N dimethylformamide on addition of 10% NaOH. The bulk of the impurities are removed by centrifugation and the dissolved organic material is recovered by water precipitation. Subsequently, the ash level is lowered from 10% in the coal to < 1.60% in the coal extracts at a washing efficiency of 33 %. The addition of Na2S (the molar ratio of NaOH to Na2S was 1:1) lowered the ash level further to 0.70%. The coal extract solution obtained showed an absorbance of 1.00 with an organic content of 8%. However, addition of sodium sulphide to the extraction medium at 25 ± 1oC lowered the organic content to 5.6%. At high temperature of 90 ± 2oC, the organic content was further lowered to 2.6% with subsequent loss in colour. The coal extract obtained by water precipitation showed low C/H atomic ratio on the addition of S-2. Nucleophiles such as cyanide, thiosulphate made no substantial change to the hydrogen content nor the degree of extraction. On coking by step heating under nitrogen to 480oC at a rate of 10oC min-1 for 1h, then to 900oC with a soaking period of 2h, the coal extracts melt, then reorganise into a liquid crystal phase around 500oC, which then solidifies into a semi-coke on further heat treatment. The heat-treatment of the coal extracts produced 75% carbon yield. When polished specimens of the cokes were observed by reflectance microscopy, flow textures with domain sizes of a few to many microns were observed. Isotropic, poorly graphitising cokes showed little or no structure. Anisotropic cokes were produced when these domains of liquid crystal grew and coalesced. The cokes were found to be highly graphitisable. However, in the heat treated coal extracts prepared at high temperature, the liquid crystal domains were graphitisable but appeared not to have coalesced. Nevertheless, the random orientation of the domains allowed isotropic blocks to be formed with extremely low crystallinity. The precursors that form these liquid crystals are generally materials known to have a high aromatic carbon content. The precursors that form these liquid crystals are generally materials with a high purity and aromatic carbon content, and low in heteroatoms. Optical microscopy of the polished samples prepared at 90  2oC revealed surfaces with much less ordered coke, having smaller crystalline domains than the heat–treated coal extracts derived at room temperature. Essentially, isotropic graphites were obtained. Addition of S-2 produced an extensive flowing texture, and a highly crystalline domain cokes. The carbon yield lowered. The graphitisability of the carbon improved. The X-ray diffraction data on the graphitised carbon showed that the degree of graphitisation decreased in the following order: high S-2 coal extracts derived at room temperature (GSF-25RT) > high S-2 coal extracts derived at high temperature (GSF-25HT) and no S-2 coal extracts derived at room temperature (GSF-0RT) > no S-2 coal extracts derived at high temperature (GSF-0HT), corresponding to 79 > 75% and 67 > 25% respectively. The interlayer spacing (d002 -value) of the graphites follows the order GSF-25RT (3.37Å) < GSF- 25HT (3.38 Å) and GSF-0RT (3.38 Å) < GSF-0HT (3.42 Å). Subsequently, the Raman spectroscopy, consistent with the X-ray diffraction data, showed the ratio of the d-peak (degenerate) to g-peak (graphitic) in the order: GSF-0HT < GSF-0RT and GSF-25HT < GSF-25RT, corresponding to 1.26 <1.75 < and 6.7 < 7.0 respectively. Because the quality of the coke depends on the nature and quality of the starting material, addition of the carbon additives in the starting material prior heat-treatment affected the flow texture of the coke. The carbon black, which has a spherical shape, forms aggregates that disperse much more easily than the flat chains of aggregates of acetylene black. The difficulty in dispersing the carbon additives was, however, overcome by using a high-shear mixer. Analysis of the coal extracts revealed that the hydrogen content in the coal extracts decreased linearly on addition of the carbon additives, favoring dehydrogenative polymerisation. The addition of carbon additives in the coal extract solution produced an isotropic carbon on heat treatment. Optical microscopy of the resin-mounted cokes revealed decreasing size of the crystalline domain with increasing dosage of the carbon additives. The optimum amount of carbon additives required was found no to exceed 0.44%. Beyond this threshold, the anisotropy of the cokes could not be observed through the resolution of the optical microscope. In addition, the amounts of volatiles released were found to decrease with increasing dosage of the carbon additives. At low dosage of the carbon additives, the heat-treated coal extracts produced graphitisable isotropic carbon with low level of crystallinity. However, at high dosage of the carbon additives, the cokes did not graphitise. The temperature of graphitisation decreased from 2976 to 2952oC with increasing dosage of the carbon additives. The decreasing order of graphitisation was 69 > 61 > 62%, corresponding to 0.44 > 0.88 > 1.60 acetylene black. With the addition of carbon black, the decreasing order of graphitisation was 57.7 > 56.5 > 51.5%, corresponding to 0.44 > 0.88 > 1.60 wt % respectively. The interlayer spacing d002, increased in the same order, suggesting a shift towards a turbostratic and formation of a poorly graphitised, and turbostratic carbon. Raman spectroscopy revealed that the intensity ratio R of the g to the d peak decreased with increasing dosage of the carbon additive. Cokes produced from the coal extracts prepared at 25oC but without S-2 showed also a remarkable degree of flow texture. Its crystalline domain units were relatively small. The resin-mounted coke samples observed under an optical microscope (objective x 25) showed reduced flow texture with the addition of carbon black. The graphitisability of the resultant cokes also decreased on addition of carbon black. The optimum dosage observed for reducing the flow texture without reducing the crystallinity was found to be < 0.22%. Improved degree of graphitisation of the carbon was studied on addition of iron (lll) compounds. Iron (lll) compounds showed a promising improvement in the graphitisability of the carbon when added in small amounts. The intracellular hard carbon is converted to soft carbon, thereby improving the degree of graphitisation. The overall effect was a more isotropic graphitic carbon but the degree of graphitisation obtained was far too low: on addition of 1% and 3% (by wt) of iron (lll), the compounds were 21% and 27% respectively. Oxygen intrusion into the precursor’s coal material prior to heat treatment is thought to have inhibited the degree of graphitisation. Increasing the amounts of the iron (lll) compound and prohibiting the intrusion of oxygen during mixing could improve the graphitisability of carbon. However, the optimum amount to be used remains an important subject to be explored in future. / Thesis (PhD (Chemistry))--University of Pretoria, 2007. / Chemistry / unrestricted

Whilst working on a Masters degree on alternative solvents and extractants for the sorghum prolamin protein, kafirin, the author serendipitously found an ethanol-free method of making kafirin microparticles in dilute organic acid. Further, on drying a suspension of kafirin microparticles in dilute organic acid, a clear, transparent film was found to be formed. Microparticles from zein, the maize prolamin protein, have shown potential for food and pharmaceutical applications. Kafirin is more hydrophobic and less digestible than zein so it was hypothesised that it may form microparticles with superior properties. However, the structural and functional characteristics of kafirin microparticles and films made from them needed to be known before any potential applications could be exploited. Kafirin microparticles were made by dissolution of kafirin in glacial acetic acid followed by precipitation on addition of water. They were characterized by Light microscopy (LM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) and were found to be mainly spherical, porous and between 1-10 ìm in diameter. The kafirin microparticles had very large internal surface area due to the presence of many smooth walled holes or vacuoles of variable sizes, probably caused by entrapment of air during microparticle formation. Increasing the final acetic acid concentration resulted in kafirin microparticles of increased size, with an increasing number of internal holes. At 40% acetic acid the spherical microparticle structures completely disappeared and were replaced by an open matrix which resembled an expanded foam. The kafirin microparticles were found to form very thin (<15 ìm) free standing films and coatings. A minimum concentration of organic acid (10.8 percent) is required to form a cohesive kafirin microparticle film relative to the concentration of protein (1 percent for acetic acid). Some functional properties, e.g. smooth film surface properties, low water vapour permeability (WVP) and low protein digestibility of these films are superior to those of similar conventionally cast kafirin films. With the aim of exploiting the porous nature of kafirin microparticles for encapsulation of nutrient additives, several factors were examined for their influence on retarding protein digestibility. Retardation of digestibility of kafirin microparticles would allow controlled release of the encapsulated agent in the stomach and gastrointestinal tract. The importance of disulphide cross-linking and sorghum condensed tannin protein interactions were confirmed as major causal factors of the poor protein digestibility of sorghum. Gamma-kafirin was found to bind the most condensed tannins compared to the a-and b- kafirins, probably due to its high proline content. As expected, the protein digestibility of kafirin-tannin complexes was much lower than unbound kafirins. This seems to slow the biodegradation of kafirin films made with bound tannins. The antioxidants, catechin and sorghum condensed tannins were encapsulated within kafirin microparticles and the antioxidant release profiles investigated under simulated gastric conditions. Over a period of four hours, catechin and condensed tannin encapsulated kafirin microparticles showed virtually no protein digestion but released approximately 70% and 50% respectively total antioxidant activity. The mechanism for the formation of kafirin microparticles and films formed from them seems to involve controlled aggregation of kafirin molecules. Models for the formation of both were proposed based on an analogy with protein body formation and the potential ability of -kafirin to undergo a structural inversion exposing either hydrophilic or hydrophobic ends depending on the prevailing conditions. Research into cross-linking by physical or chemical agents is needed before practical applications can be exploited. However, encapsulation of catechin and sorghum condensed tannins within kafirin microparticles seems to be an effective way to use the binding properties of polyphenols with protein to enhance potential health benefits by controlled release of antioxidant activity within the stomach and gastrointestinal tract. Copyright / Thesis (PhD)--University of Pretoria, 2009. / Food Science / unrestricted

The problem presented is how to handle encoded data for which the encodings or decodings change with respect to time, and which contains codes indicating that certain data is unknown, invalid, or not applicable with respect to certain entities during certain time periods. It is desirable to build a database management system that is capable of knowing about and being able to handle the changes in encodings and the missing information codes by embedding such knowledge in the data definition structure, in order to remove the necessity of having applications programmers and users constantly worrying about how the data is encoded. The experimental database management language DEFINE is utilized to achieve the desired result, and a database structure is created for a real-life example of data which contains many examples of time-variant encodings and missing information. / Science, Faculty of / Computer Science, Department of / Graduate

The aim of this bachelor’s thesis is to go through the process of preparing a specific repertoire for the purpose of perfomance at a piano competition during the Covid-19 world pandemic. The goal will be to give an analysis of such process, and understand the differences and requirements it entails in comparison to the preparation for piano competitions under normal circumstances.  I have used a journal to relate the process and write about the overall experience, as well as videos from group lessons and other performances, insights from my professor and peers and my own analysis of this method as material to examine this subject.I aspire to provide aid for other musicians who show interest in this topic and look for both ideas and other pianists’ experience in the process of competing.

Pre-service teachers are entering the field as novice practitioners with concerns regarding their ability to confidently and effectively implement key components of response to intervention (RTI). This concurrent mixed-methods study explores pre-service teachers' (N =169) perceptions and experiences with key components of RTI (e.g., screening, multi-tiered evidence-based intervention, progress monitoring, and data-based decision making). A questionnaire in conjunction with open-response items and four focus groups provided data to identify aspects of university coursework and field experiences that contribute to pre-service teachers' perceived ability to confidently implement key components of RTI. The results of this investigation show between group differences in perception and experiences related to RTI. Special education certification seekers reported higher perceived confidence, receiving more coursework, and having more field experiences with RTI than elementary, middle grade, and secondary certification seekers. Among all groups, secondary certification seekers reported the lowest confidence, least amount of coursework, and fewest field experiences with RTI. Pre-service teachers in this study valued coursework and knowledgeable instructors who emphasized the components of RTI and participating in hands-on class activities. Participants noted benefits from or a desire for field experiences with struggling learners and having mentors with knowledge and expertise in RTI. Study findings suggest providing pre-service teachers with comprehensive preparation in RTI during coursework in combination with field experiences working with struggling learners may increase perceived confidence and is valued.

Background: Bowel preparation is essential for quality colonoscopy. Although most bowel preparation regimens recommend dietary restriction for 24 to 48 hours before the procedure, the evidence for this is poor. Objectives: To establish whether dietary restriction during bowel preparation improves the quality of bowel preparation. Methods: A prospective single blind, randomised controlled pilot study. The dietary restriction (DR) group was instructed not to ingest high fibre foods for 48 hours prior to the use of a polyethylene glycol (PEG) bowel preparation. The non-dietary restriction (NDR) group was not given any dietary modification, but received instructions for the use of the PEG-based preparation solution. On the day of colonoscopy, the quality of the bowel effluent was assessed, and additional preparation given as necessary. The primary endpoint was quality of bowel cleansing using the Harefield Cleansing Scale during colonoscopy. The secondary endpoint was the need for additional bowel preparation and quantity of additional bowel preparation given prior to endoscopy. Data were analysed on an intention to treat basis. Results: Twenty-three participants were randomised to the intervention group and thirty-four to the control group. Patient demographics were similar in both groups. Dietary restriction did not influence the success rate of bowel preparation: 97% successful bowel preparation in the DR group, vs 91% successful bowel preparation in the NDR group (p=0.559). Additional bowel preparation requirement were similar in both groups: 35% in DR group vs 39% in NDR group (p=0.768). Mean amount of additional bowel preparation required was similar: 560 ml in the DR group vs 460 ml in the NDR group (p=0.633). Conclusion: The quality of bowel preparation was comparable in patients with and without dietary restrictions prior to colonoscopy. Non-restrictive diets prior to bowel preparation should be considered to increase compliance. The sample size of this pilot study prohibited definite statistical conclusions but demonstrated this to be a reasonable methodology for a larger study.