73 results on '"Alan Christie"'
Search Results
2. Production of PHB Scaffolds Reinforced with HAp Through Electrospinning
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Tácito Iago Dourado dos Santos, Alan Christie da Silva Dantas, Nelson Cárdenas Olivier, Andre Moreira, Caio Oliveira, and José Américo de Sousa Moura
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Electrospinning ,Hydroxyapatite ,Polyhydroxybutyrate ,Scaffold ,Tissue engineering ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Electrospinning, an economical technique, is widely used for biomedical scaffold fabrication, crucial in tissue and organ regeneration, particularly with biomaterials. Polymers, either pure or reinforced with ceramics, aid in cell proliferation and tissue formation. Polyhydroxybutyrate (PHB) is a promising biopolymer for tissue engineering, offering biocompatibility comparable to petroleum-derived polymers. Combining PHB with hydroxyapatite (HAp) enhances mechanical strength and osteoconductivity. This study aims to produce electrospun PHB microfibrous webs reinforced with HAp for scaffold fabrication. Morphological variations are analyzed through manipulation of electrospinning parameters. The study observed microfibrous webs with diameters ranging from 2 to 9 µm. Mechanical and microstructural evaluations demonstrate superior strength of PHB/HAp microfibrous webs compared to pure PHB, 1.23 MPa and 0.58 MPa respectively, demonstrating the efficacy of HAp reinforcement. These findings highlight the potential of PHB/HAp microfibrous webs in bone tissue engineering.
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- 2024
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3. Case report: A rare case of immunotherapy induced isolated left CN VI palsy in a patient with unresectable melanoma
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Samantha Su Ping Low, Karim El-Shakankery, Ewan Brown, Alan Christie, Sally McCormack, and Mark Stares
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case report ,immunotherapy ,immune-related adverse events ,cranial nerve palsy ,unresectable melanoma ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
IntroductionImmune checkpoint inhibitors are the mainstay of treatment in patients with unresectable or metastatic melanoma. Combination immunotherapy with ipilimumab and nivolumab has shown to improve survival outcomes as compared to single agent immunotherapy in these patients. Neurological immune-related adverse effects (irAEs) are uncommon and cranial nerve palsies are seen even more infrequently.Case presentationA 66-year-old woman with a background of metastatic, unresectable melanoma with supraclavicular and axillary lymph nodal involvement presented with a headache, photophobia and diplopia 3 weeks after her first cycle of ipilimumab and nivolumab. She was subsequently diagnosed with a left-sided cranial nerve VI palsy and treated with high dose oral steroids and steroid eye drops, with complete resolution of symptoms. She also experienced Grade 3 dermatitis requiring topical steroids, Grade 2 hypothyroidism and vitiligo. She continues to have an excellent clinical and radiological response, despite further immunotherapy being suspended.ConclusionThis is the first reported UK case of immunotherapy-induced isolated cranial nerve VI palsy. Multiple irAEs are more common with combination immunotherapy and its occurrence is associated with more favourable outcomes in melanoma. Immunotherapy continues to revolutionise oncological care, but clinicians must be cognizant of unpredictable irAEs, which may require prompt assessment and intervention.
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- 2024
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4. Case Report of Exercise to Attenuate Side Effects of Treatment for Pancreatic Cancer
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Marie McLaughlin, Alan Christie, and Anna Campbell
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pancreatic cancer ,exercise ,chemotherapy ,case report ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Treatments for pancreatic cancer can have debilitating side effects including fatigue, weight loss, and cardiac toxicity, resulting in functional loss and psychological distress. Exercise has been proposed as a therapy to counteract physical and psychological detriments. The case: A 47-year-old male undergoing chemotherapy for stage 3 locally advanced pancreatic cancer. He was cycling during hospital chemotherapy infusions (6 fortnightly cycles of FOLFIRINOX: 5-FU 2, 400 mg/m2, over 48 h: irinotecan 180 mg/m2, oxaliplatin 85 mg/m2, no 5-FU bolus) plus 12 weeks of twice weekly aerobic and resistance exercise. Over 12 weeks, body composition was maintained, and physical function improved, with specific increases in muscular strength of up to 50% and aerobic capacity improving by 9%. Moreover, quality of life, fatigue, psychological distress, and sleep quality improved by 38, 113, 50, and 9%, respectively. Additionally, the participant experienced more severe side effects in week 6, when he did not cycle to a high intensity during hospital infusion and had less total weekly exercise. After cycle 6 (week 11), chemotherapy was halted, and a Whipple resection procedure was successfully performed. It can be concluded that regular aerobic and resistance exercise plus exercise during infusion can attenuate expected decline in physical and mental health with pancreatic cancer treatment and may reduce treatment side effects and have favourable effects on prognosis.
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- 2019
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5. The production of hydroxyapatite prototypes from solid bodies of gypsum/polyvinyl alcohol composites
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Amanda Alves Barbosa, Andréa de Vasconcelos Ferraz, Alan Christie Dantas, and Nelson Cárdenas Olivier
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hydroxyapatite ,gypsum ,PVA ,prototypes ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Prototypes of porous hydroxyapatite (HAp) were produced from Gypsum/PVA composite, using a mass proportion of 15% polymer. The material was obtained by means of chemical conversion in (NH4)2HPO4 0.5 mol.L-1 solution and NH4OH 6.0 mol.L-1 alkaline medium for pH control, maintained between 6.0 and 9.0. The reaction occurred at a temperature of 100ºC at different test times. The obtained HAp was characterized by several techniques, such as FTIR, which identified the SO4(2-) groups characteristic for the Gypsum block, and the PO4(3-) groups that are attributed to the biomaterial HAp, besides XRD and SEM, which made it possible to confirm a successful conversion of the material. Tests for mechanical resistance to compression (σc) were carried out for both materials as well.
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- 2014
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6. Mechanical behavior of pumpkin fruits subjected to compression during maturation
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Acácio Figueiredo Neto, Francisco de Assis Cardoso Almeida, Nelson Cárdenas Olivier, Alan Christie Silva Dantas, and Marcos Antonio Silva Irmão
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Rheological properties ,mechanical damage ,deformability modulus ,Agriculture (General) ,S1-972 - Abstract
During handling operations, many problems that reduce the quality of vegetables may occur. Mechanical injuries are the leading cause of postharvest losses for the pumpkin, and can take place at any point of the production chain. This study aimed at evaluating the pumpkin fruits behavior, during their ripening stages, on the values of maximum compression force for fixed deformations, and determining the proportional deformability modulus of the fruits under compression at the repose position. Fruits were harvested at 15, 30, 40, 50 and 60 days after flowering and uniaxially compressed between two parallel plates. The results allowed to conclude that both the required compression force and the proportional deformability modulus increased during the maturation course, reaching a maximum force of 1,778 N and a maximum deformation modulus of 164 MPa, after 30 days. After this period, both the maximum force and the modulus values decreased, reaching 1,514.8 N of maximum force and a modulus of 132.09 MPa, after 60 days of ripening. Over the course of a longer maturation time, the fruit firmness increased, therefore requiring an increase in the maximum load to achieve greater deformation. The ideal period for harvest and transport of 'Jacarezinho' pumpkin fruits was set from 30 to 40 days after anthesis.
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- 2013
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7. Comportamiento mecánico de dos variedades de mango (Mangifera Indica) bajo compresión axial
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Luis Ivan Negrín Hernández, Rômulo Barros Barbosa, Alan Christie Da Silva Dantas, Acácio Figueiredo Neto, and Nelson Cárdenas Olivier
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Agriculture ,Environmental technology. Sanitary engineering ,TD1-1066 - Abstract
En este trabajo se caracteriza la respuesta mecánica del mango en función de los problemas encontrados durante las etapas de producción y comercialización. Problemas como daños físicos provocados por la manipulación inadecuada de la fruta, sea en el momento de la cosecha, almacenamiento, procesamiento o transporte. Los problemas señalados son característicos de la falta de información sobre el máximo esfuerzo que el fruto puede soportar sin que el mismo sufra daño interno o rotura externa que comprometa su comercialización. Fueron realizados ensayos de compresión en mangos (Mangifera Indica) de las variedades “Keitt” y “Tommy Atkins”, en la posición natural de reposo, lo que posibilitó la determinación del módulo de elasticidad y la fuerza máxima soportada en función de las fases 1, 2 y 3 de maduración. El módulo de elasticidad se reduce con el avance de la fase de maduración, obteniéndose valores para la variedad “Keitt” de 2,065 MPa, 1,734 MPa y 1,381 MPa para las fases de maduración 1, 2 y 3 respectivamente, y para la variedad “Tommy Atkins” de 1,698 MPa, 1, 657 MPa y 1,518 para las mismas fases de maduración. Las medidas de las fuerzas máximas, que antecede la rotura de la fruta, soportadas por la variedad “Tommy Atkins” fueron superiores a las soportadas por la “Keitt”. Este hecho está relacionado con la diferente organización estructural de estas dos variedades, en la que la variedad “Tommy Atkins” presenta un porciento de fibra superior a la variedad “Keitt”.
- Published
- 2013
8. SOUND POWER LEVEL EMITTED BY AGRICULTURAL TRACTOR UNDER STATIC AND DINAMIC CONDITIONS NÍVEIS DE POTÊNCIA SONORA EMITIDOS POR TRATOR AGRÍCOLA EM CONDIÇÕES ESTÁTICAS E DINÂMICAS
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Alan Christie da Silva Dantas, Jorge Wilson Cortez, Fernanda Rodrigues Lima da Costa, Aline Dantas da Silva Alves, and Hideo de Jesus Nagahama
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Ruído ,ergonomia ,mecanização agrícola ,Agriculture (General) ,S1-972 - Abstract
The noise produced by farm machinery may cause hearing problems to its operators along the time. The objective of this study was to evaluate the sound power level emitted by agricultural tractor under static and dynamic conditions, in relation to the IEC651 and IEC61672 norms. It was conducted at the Universidade Federal do Vale do São Francisco, in Petrolina, Pernambuco State, Brazil, in 2009, by using a Valtra 785 TDA tractor without cabin and equipment to measure its sound power level. The measurements were: static (anterior, posterior, right, and left positions, in relation to the operator’s seat, for each meter along the maximum distance of 10 m, and different engine rotation speeds, with two measuring devices) and dynamic (five speeds on concrete and soil test tracks, with two devices). Two measurement devices were used to evaluate the sound power level. For the devices in accordance with the IEC651 and IEC62672 norms, the second one always presented higher sound power levels, due to the fact that the first one was equipped with a wind protector. In all positions, the sound power level was higher than allowed by law. As the engine rotation speed increases, the sound power level also increases. It was noticed that both test tracks can be used for sound power level analysis, due to their similar results. The tractor speed affected its sound power level, with higher values for longer gears.KEY-WORDS: Noise; ergonomics; agricultural mechanization.O ruído das máquinas agrícolas, com o passar do tempo, pode provocar problemas auditivos em seus operadores. O objetivo deste trabalho foi avaliar o nível de potência sonora emitido por trator agrícola, em condições estáticas e dinâmicas, comparando-o às normas IEC651 e IEC61672. O trabalho foi realizado na Universidade Federal do Vale do São Francisco, Petrolina (PE), em 2009, utilizando-se um trator Valtra, modelo 785 TDA sem cabine, e medidores do nível de potência sonora. As medições foram: estática (posições anterior, posterior, direita e esquerda do assento do operador a cada metro, até a distância máxima de 10 m, e diferentes rotações do motor, com dois equipamentos de medição) e dinâmica (cinco velocidades de deslocamento, em pista de concreto e terra batida, utilizando-se dois equipamentos de medição). Para os equipamentos que atendem às normas IEC651 e IEC61672, o segundo sempre apresentou maiores valores do nível de potência sonora, devido ao primeiro ser utilizado com protetor de vento. Em todas as condições, o nível de potência sonora foi maior do que o permitido pela legislação. À medida que se aumenta a rotação do motor, ocorre incremento no nível de potência sonora. Verificou-se que as pistas de terra batida e concreto podem ser utilizadas para análise do nível de potência sonora, devido aos resultados similares apresentados. A velocidade de deslocamento do trator influenciou no nível de potência sonora, sendo que as marchas mais longas apresentaram maiores valores. PALAVRAS-CHAVE: Ruído; ergonomia; mecanização agrícola.
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- 2011
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9. ENGENHARIA REVERSA: CULTIVANDO O INTERESSE NO ÂMBITO AUTOMOTIVO
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Nascimento, Matheus de Souza, primary, Medeiros, José Bismark de, additional, and Dantas, Alan Christie da Silva, additional
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- 2023
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10. Avaliação das propriedades mecânicas de fios de pesca de poliamida para aplicação como suturas em cirurgias veterinárias
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Silva, Josilane Soares da, primary, Silva, Willas Matias da, additional, Barbosa, Jefferson Natanael, additional, Baraúna Júnior, Durval, additional, Nesio, Francimario Beserra, additional, Cordeiro, Erlon Rabelo, additional, Silva, Alan Christie Da, additional, Negrin, Luis Iván, additional, Irmao, Marcos Antonio da Silva, additional, and Olivier, Nelson Cárdenas, additional
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- 2022
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11. Influência da ação de sais solúveis na resistência das argamassas, em Petrolina PE
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Calado, Bruno Marinho, primary, Dantas, Alan Christie da Silva, additional, and Queiroz, Thiago César de Andrade, additional
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- 2022
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12. Production of PHB Scaffolds Reinforced with HAp Through Electrospinning
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Santos, Tácito Iago Dourado dos, primary, Dantas, Alan Christie da Silva, additional, Olivier, Nelson Cárdenas, additional, Moreira, Andre, additional, Oliveira, Caio, additional, and Moura, José Américo de Sousa, additional
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- 2024
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13. ENGENHARIA REVERSA: CULTIVANDO O INTERESSE NO ÂMBITO AUTOMOTIVO
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Matheus de Souza Nascimento, José Bismark de Medeiros, and Alan Christie da Silva Dantas
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- 2023
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14. Characterisation and outcomes of patients referred to a regional cancer of unknown primary team: a 10-year analysis
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Marjory MacLennan, Karin Purshouse, Sally Clive, Mark Stares, C. Barrie, Rachel Haigh, Rebekah Patton, Aoife Gatenby, Jo McGinty, Jenny Irvine, Alan Christie, and Gillian Knowles
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Male ,Cancer Research ,medicine.medical_specialty ,Time Factors ,MEDLINE ,Article ,Secondary care ,Cancer of unknown primary ,Regional cancer ,medicine ,Humans ,Prospective Studies ,Pathological ,Aged ,business.industry ,General surgery ,Cancer ,medicine.disease ,Treatment Outcome ,Oncology ,Unknown primary ,Neoplasms, Unknown Primary ,Female ,business ,Median survival - Abstract
Background In the United Kingdom, national guidance published in 2010 recommended the establishment of specialist teams to improve clinical pathways for patients presenting with malignancies of undefined primary origin (MUO) and cancer of unknown primary (CUP). This study sought to define outcomes of patients referred to a regional MUO/CUP service. Methods Data were collected prospectively on all patients (n = 1225) referred to a regional CUP team over a 10-year period. Patient demographics, clinical, pathological and outcome data were recorded and analysed. Results Confirmed CUP (cCUP) was diagnosed in 25% of patients. A primary metastatic cancer was identified in 36%, 5% were diagnosed with provisional CUP (pCUP), 27% retained the diagnosis of MUO and in 8% a non-cancer diagnosis was made. Median survival was low in all patients with a final malignant diagnosis: primary identified 9.0 months, cCUP 4.0 months, pCUP 1.5 months and MUO 1.5 months. Conclusions Patients presenting with MUO have poor outcomes irrespective of the final diagnosis. These patients need a patient-centred, streamlined, rapid diagnostic pathway. There are clear benefits to primary and secondary care teams having access to a dedicated, multidisciplinary MUO/CUP service, with clinical nurse specialists supporting the patients, to help facilitate this pathway and ensure early oncology review.
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- 2021
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15. Advance care planning in primary care for patients with gastrointestinal cancer : feasibility randomised trial
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Anne Canny, Bruce Mason, Jacqueline Stephen, Samantha Hopkins, Lucy Wall, Alan Christie, Richard JE Skipworth, Joanna Bowden, Louise Graham, Marilyn Kendall, Christopher J Weir, Kirsty Boyd, University of St Andrews. Arctic Research Centre, and University of St Andrews. School of Medicine
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Adult ,MCC ,Mixed methods ,Adolescent ,Primary Health Care ,RC0254 Neoplasms. Tumors. Oncology (including Cancer) ,Palliative Care ,NDAS ,Anticipatory care planning ,NIS ,humanities ,RC0254 ,Advance Care Planning ,SDG 3 - Good Health and Well-being ,RA Public aspects of medicine ,Feasibility Studies ,Humans ,Family Practice ,General practice ,RA ,Gastrointestinal Neoplasms ,Cancer ,Primary health care ,Advance care planning - Abstract
BackgroundAdvance (anticipatory) care planning (ACP) requires discussions between patients and healthcare professionals about planning for future deterioration in health. ACP improves care coordination but uptake is limited and often deferred.AimTo assess the feasibility and acceptability to patients, carers, and GPs of a primary care ACP intervention for people with incurable oesophageal, gastric, or pancreatic cancer.Design and settingA 12-month feasibility randomised controlled trial (RCT) in a Scottish Cancer Network.MethodPatients aged ≥18 years starting palliative oncology treatment were randomised 1:1 to an ACP intervention or standard care. Patients in the intervention group received an oncologist letter supporting them to request a GP review along with a patient information leaflet about ACP. Pre-specified analyses with masking included trial recruitment and retention, ACP completion, and quality-of-life questionnaires (EuroQol EQ-5D-5L and ICECAP Supportive Care Measure) at baseline, 6, 12, 24, and 48 weeks. Qualitative interviews with purposive sampling explored patient, carer, and GP experiences.ResultsOf 99 eligible participants (269 screened), 46% were recruited (n = 46) and randomised; 25 to intervention and 21 to control. By 12 weeks, 45% (n = 9/20) of the individuals in the intervention and 59% (n = 10/17) in the control group had a documented ACP plan. By 24 weeks, 30% (n = 14) had died; in the remaining participants quality of life was maintained at 24 weeks except for physical symptoms. Social norms associating ACP with dying were prevalent among 23 participants interviewed. No psychological or clinical harms were identified.ConclusionAn RCT of ACP for people with incurable cancer in primary care is feasible. Patient, carer, and GP attitudes and behaviours determined acceptability and timing of care planning.
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- 2022
16. Avaliação das propriedades mecânicas de fios de pesca de poliamida para aplicação como suturas em cirurgias veterinárias
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Josilane Soares da Silva, Willas Matias da Silva, Jefferson Natanael Barbosa, Durval Baraúna Júnior, Francimario Beserra Nesio, Erlon Rabelo Cordeiro, Alan Christie Da Silva, Luis Iván Negrin, Marcos Antonio da Silva Irmao, and Nelson Cárdenas Olivier
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- 2022
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17. Influência da ação de sais solúveis na resistência das argamassas, em Petrolina PE
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Bruno Marinho Calado, Alan Christie da Silva Dantas, and Thiago César de Andrade Queiroz
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- 2022
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18. ESTRUTURAÇÃO DO SETOR DE MANUTENÇÃO DE UMA EMPRESA DO RAMO DO AGRONEGÓCIO LOCALIZADA NO VALE DO SÃO FRANCISCO
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Danillo Emanuel Leite Guimarães, Fernanda Cavalcante de Alencar, and Alan Christie da Silva Dantas
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- 2022
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19. Mechanical Properties of a Composite of Gypsum Reinforced with Caroá Fiber and PVAc
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Alessandra Félix da Costa Pereira, Aoliabe Pedro da Silva, Edpo Ferreira Santos, Alan Christie da Silva Dantas, and Nelson Cárdenas Olivier
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010302 applied physics ,Gypsum ,Materials science ,Mechanical Engineering ,Composite number ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Mechanics of Materials ,0103 physical sciences ,engineering ,General Materials Science ,Fiber ,Composite material ,0210 nano-technology - Abstract
The Development of new materials for building industry is a necessary issue to promote sustainability. Gypsum is an important low cost material very abundant in the northeast region of Brazil. Its physical properties make it an interesting material to form composite materials. This work presents a study of gypsum reinforced with Caroá (neoglasiovia variegate) natural fibers, where different amounts of fibers (1, 2, and 3%) were added into gypsum matrix. Three different fiber sizes (5, 10, and 20mm) were used to evaluate the effect of fiber size on the properties. PVAc was added in order to enhance the interactions between matrix and fibers. Mechanical strength was characterized by compression and bending tests. The addition of 1% mass Caroá fibers leads to a slightly increase on the mechanical strength independently of fiber size.
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- 2019
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20. Determination Compressive and Bending Strength of Porous Bodies from Plaster Reinforced with Polyacetate of Vinila (PVAc)
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Aoliabe Pedro da Silva, Nelson Cárdenas Olivier, Laudir de Castro Ferreira Neto, Alan Christie da Silva Dantas, and Alessandra Félix da Costa Pereira
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Materials science ,Flexural strength ,Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Composite material ,Condensed Matter Physics ,Porosity ,Compression (physics) - Abstract
Calcium sulfate dehydrate β (CaSO4. 0,5H2O) is a material obtained from the calcination of gypsite (CaSO4.2H2O). This is a low cost ceramic material very used in building industry. The improvement of their applications is of fundamental technological interest. Polymers are an interesting alternative of reinforcement. Polyvinyl acetate (PVAc) is an addition polymer obtained by the polymerization of vinyl acetate. This polymer is well known to achieve good adhesion to cellulosic surfaces. The aim of this work was to evaluate the mechanical properties of porous plaster bodies reinforced with PVAc. Mechanical behavior was characterized by compression and bending strength. Three water / gypsum ratios: 0.5 0.6 and 0.7 were used on this work. An amount of 5% and 10% PVAc promoted increase on the mechanical properties of gypsum. Higher amounts polymer promoted further decrease of the mechanical properties.
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- 2019
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21. Comportamiento mecanico de dos variedades de mango (Mangifera Indica) bajo compresion axial
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Negrín Hernández, Luis Ivan, Barros Barbosa, Rômulo, Da Silva Dantas, Alan Christie, Figueiredo Neto, Acácio, and Cárdenas Olivier, Nelson
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- 2013
22. Estudo Comparativo da Influência do Uso de Hidrorrepelentes nas Propriedades no Estado Fresco e no Estado Endurecido do Gesso Beta
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Rodrigues, Sheila Daiane De Souza, primary, De Sousa, José Getúlio Gomes, primary, Dantas, Alan Christie da Silva, primary, Hernández, Luis Iván Negrín, primary, Silva, Mateus Amorim, primary, and Olivier, Nelson Cárdenas, primary
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- 2021
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23. GAINS IN PERFORMANCE OF DIESEL CYCLE ENGINE USING B10 COMPARED TO OTHER MIXTURES
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Camila Coelho Guimarães, Vivianni Marques Leite dos Santos, Paulo José Pereira, Jorge Wilson Cortez, and Alan Christie da Silva Dantas
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Biodiesel ,Diesel fuel ,Biofuel ,law ,Electric generator ,Environmental science ,General Medicine ,Thrust specific fuel consumption ,Renewable fuels ,Diesel cycle ,Diesel engine ,Automotive engineering ,law.invention - Abstract
Studies to develop renewable fuels, such as biodiesel, as substitutes for petroleum diesel have a great environmental importance. However, in order to be effectively incorporated into the energy mix, a satisfactory performance of a diesel cycle engine under the effect of this biofuel must be ensured. The objective of this study was to evaluate the specifc fuel consumption, effective power and torque of a diesel engine related to resistive loads under varying volumetric proportions of soybean biodiesel in mineral diesel oil (5% (B5), 10% (B10), 25% (B25) and 50% (B50)) under varying applied loads (1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 kW). For the test, a 7.36 kW engine coupled to a 28.8 kW three-phase electric generator was used. The loads were elevated up to 9.0 kW via a three-phase resistive bench. In terms of power and torque, the performances of the B5 and B10 mixtures were not signifcantly different, whereas the B25 and B50 mixtures displayed lower performances. The B10 mixture showed better performance in terms of consumption because the remaining mixtures had similar results to those B5 mixture. For this reason, it can be a basis for encouraging anticipation of this mixture in diesel cycle engines use. Additionally, the reduction in power and torque for mixtures with higher concentration of biodiesel should not be considered signifcant front the environmental gains from the use of renewable fuels and the analyzed technical aspects.
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- 2018
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24. Use of a modified Delphi approach to develop research priorities in HPB surgery across the United Kingdom
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Michael Wilson, Keith J. Roberts, Mark A. Taylor, Ewen M Harrison, Samir Pathak, Hayley Davies, Alan Christie, Stephen R Knight, Giles J. Toogood, P G Vaughan-Shaw, Jonathan Rees, and Louise Jones
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Biomedical Research ,Delphi Technique ,media_common.quotation_subject ,Digestive System Diseases ,Modified delphi ,MEDLINE ,Delphi method ,03 medical and health sciences ,0302 clinical medicine ,Quality of life (healthcare) ,Multidisciplinary approach ,Medicine ,Upper gastrointestinal ,Humans ,Quality (business) ,computer.programming_language ,media_common ,Medical education ,Hepatology ,business.industry ,Health Priorities ,Gastroenterology ,United Kingdom ,Centre for Surgical Research ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,business ,computer ,Delphi - Abstract
BackgroundResearch prioritisation can help identify clinically relevant questions and encourage high-quality, patient-centred research. Delphi methodology aims to develop consensus opinion within a group of experts, with recent Delphi projects helping to define the research agenda and funding within several medical and surgical specialties.MethodsAll members of the Association of Upper Gastrointestinal Surgeons (AUGIS) were asked to submit clinical research questions using an online survey (Phase 1). Two consecutive rounds of Delphi prioritisation by multidisciplinary HPB healthcare professionals (Phase 2) were undertaken to establish a final list of the most highly prioritised research questions. A multidisciplinary steering committee analysed the results of each phase.ResultsNinety-three HPB-focussed questions were identified in Phase 1, with thirty-seven questions of sufficient priority to enter a further prioritisation round. A final group of 11 questions considered highest priority were identified. The most highly ranked research questions related to treatment pathways, operative strategies and the impact of HPB procedures on quality of life, particularly for malignant disease.ConclusionExpert consensus has identified research priorities within the UK HPB surgical community over the coming years. Funding applications, to establish well-designed, high quality collaborative research are now required to address these questions.
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- 2019
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25. Production of Single-Phase Hydroxyapatite Porous Bodies from Gypsum/Polystyrene
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Andréa de Vasconcelos Ferraz, Amanda Alves Barbosa, Geciane A. Santos, Nelson Cárdenas Olivier, and Alan Christie da Silva Dantas
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chemistry.chemical_classification ,Materials science ,Gypsum ,Mechanical Engineering ,Mixing (process engineering) ,Polymer ,engineering.material ,Condensed Matter Physics ,Solvent ,chemistry.chemical_compound ,Compressive strength ,chemistry ,Mechanics of Materials ,Acetone ,engineering ,General Materials Science ,Polystyrene ,Composite material ,Porosity - Abstract
Porous bodies were produced using hydroxyapatite as a starting material, gypsum, high purity material, low cost and that can be molded into the desired shape. Also, beads of polystyrene polymer. The first step of this work was to produce porous gypsum blocks obtained by mixing gypsum, water and polystyrene. After drying, they were submerged in acetone solvent for solubilizing the polymer and pore formation. The porous hydroxyapatite was synthesized in a second stage, where the porous gypsum blocks were immersed in a solution of (NH4)2HPO4 0.5 mol L-1 to 100 ° C and pH 7.0-9.0 for 24 hours. From this method, it was possible to produce bodies single phase hydroxyapatite with a maximum porosity of 70 ± 3% and a compressive strength of 1.48 ± 0.17 MPa.
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- 2016
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26. Caracterização mecânica de mangas usando testes de compressão
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Dantas, Alan Christie Da Silva, Barbosa, Romulo, Neto, Acácio Figueiredo, Olivier, Nelson Cárdenas, and Negrin Hernández, Luiz Iván
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0106 biological sciences ,Chemistry ,040103 agronomy & agriculture ,food and beverages ,0401 agriculture, forestry, and fisheries ,04 agricultural and veterinary sciences ,General Medicine ,01 natural sciences ,010606 plant biology & botany - Abstract
Brazil is one of the largest producers of mangoes, and the São Francisco Valley accounts for about 87 % of Brazilian exports of this product to the European market. This study aimed to characterize the mechanical behavior of the fruits according to the maturation stages, in order to prevent physical damage caused by improper handling of the fruit during harvest, storage, processing and transportation. The compression tests were performed on the mango cultivars (Mangifera indica L.) Keitt and Tommy Atkins at different maturation stages in order to characterize the internal elastic modulus and determine the maximum stress until rupture of the sleeve. The fruits showed a decrease in mechanical properties correlated with the increase of maturation stage, for both cutivars. The Tommy Atkins variety showed better mechanical properties probably related to a higher concentration of fibers in the pulp which yields better mechanical stabilization., Revista de Ciências Agrárias, vol. 40 n.º 2 (2017)
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- 2019
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27. Mechanical Properties of a Composite of Gypsum Reinforced with Caroá Fiber and PVAc
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Santos, Edpo Ferreira, primary, da Silva, Aoliabe Pedro, additional, Olivier, Nelson Cárdenas, additional, Pereira, Alessandra Félix da Costa, additional, and Dantas, Alan Christie da Silva, additional
- Published
- 2019
- Full Text
- View/download PDF
28. Determination Compressive and Bending Strength of Porous Bodies from Plaster Reinforced with Polyacetate of Vinila (PVAc)
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da Silva, Aoliabe Pedro, primary, Ferreira Neto, Laudir de Castro, additional, Olivier, Nelson Cárdenas, additional, Pereira, Alessandra Félix da Costa, additional, and Dantas, Alan Christie da Silva, additional
- Published
- 2019
- Full Text
- View/download PDF
29. Design of Highly Porous Hydroxyapatite Scaffolds by Conversion of 3D Printed Gypsum Structures – A Comparison Study
- Author
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Roberta De Farias, Andréa de Vasconcelos Ferraz, Cynthia Wirth, Alan Christie da Silva Dantas, Amanda Alves Barbosa, and Debora H. Scalabrin
- Subjects
3d printed ,Gypsum ,Materials science ,business.industry ,Metallurgy ,3D printing ,02 engineering and technology ,engineering.material ,Hydroxiapatite ,021001 nanoscience & nanotechnology ,gypsum ,CNC machining ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Highly porous ,engineering ,Comparison study ,General Earth and Planetary Sciences ,0210 nano-technology ,business ,General Environmental Science - Abstract
Hydroxyapatite (HA) is a bioceramic material with excellent biological properties. However, these properties are strongly dependent of its crystallinity degree, with high values of crystallinity associated to poor resorption rates and bioactivity. This work evaluates the properties of HA samples produced by two different free-forming conformation methods, CNC machining and 3D printing. In both cases, porous gypsum samples were produced and subsequently converted into HA in a reaction with di-ammonium hydrogen phosphate at 100°C and pH 8. A total conversion of the samples was achieved after 36h independently of the conformation method used. The microstructure, however, before and after the conversion is showed to be dependent on the method used. After conversion the machined samples achieved a maximum compressive strength of 3.5 MPaforporosities of circa 80%, while 3D printed samples achieved a tensile strength of 2.0MPa by porosities of 61%.
- Published
- 2016
- Full Text
- View/download PDF
30. Modeling of Two-Dimensional Orthotropic Heat Conduction in Porous Gypsum
- Author
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José Pereira Alencar, Alan Christie da Silva Dantas, Andréa de Vasconcelos Ferraz, Carlos R.N. Souza, and Nelson Cárdenas Olivier
- Subjects
Thermal contact conductance ,Materials science ,Gypsum ,business.industry ,Mechanical Engineering ,Mineralogy ,engineering.material ,Condensed Matter Physics ,Thermal conduction ,Thermal diffusivity ,Thermal conductivity measurement ,Thermal conductivity ,Mechanics of Materials ,Thermal insulation ,engineering ,General Materials Science ,Composite material ,business ,Porosity - Abstract
The gypsum is a versatile material that shows low thermal conductivity, which makes this material very suitable for application as thermal insulation. The increase of the porosity of gypsum bodies promotes a decrease on the thermal conductivity. This effect optimize the range of applications of gypsum on the thermal insulate field. The present study aimed the numerical modeling of two-dimensional heat conduction by finite differences in a steady state to evaluate the ortotrophy of the thermal conductivity of porous gypsum using the elements of the protected hot plate method. Computer simulations were performed using thermal conductivity of the gypsum equal to 0.35 W/m.K. This value was varied on the x and y directions by 5%, 10% and 15%. The heat flow applied to the numerical simulations were equal 75 W/m2, 100 W/m2 to 125 W/m2.It was possible to produce temperature profiles where is visible the displacement of isotherms as a function of the change in thermal conductivity in the x direction.
- Published
- 2015
- Full Text
- View/download PDF
31. Production of Hydroxyapatite/Polyhydroxibutirate Based Composites for Biomaterials Applications
- Author
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Wilson Acchar, Andréa de Vasconcelos Ferraz, Nelson Cárdenas Olivier, Alan Christie da Silva Dantas, Leticia M. Oliveira, and Geciane A. Santos
- Subjects
Materials science ,Mechanical Engineering ,Composite number ,technology, industry, and agriculture ,Young's modulus ,Condensed Matter Physics ,Bone tissue ,Biodegradable polymer ,Polyhydroxybutyrate ,symbols.namesake ,Compressive strength ,medicine.anatomical_structure ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,symbols ,medicine ,General Materials Science ,Ceramic ,Composite material ,Porosity - Abstract
Hydroxyapatite (HA) is a ceramic material broadly studied due to its great similarity with the human bone. However, this material presents high stiffness and young modulus in comparison with the bone tissue. The polyhydroxybutyrate (PHB) is a themoplatic and biodegradable polymer that presents bone like young modulus and gradative degradation that results in a permanence of the mechanical properties after implantation. The aim of this study is to evaluate the effect of the infiltration of melted PHB on the mechanical properties of porose HA bodies. The composite samples were characterized by SEM, EDS and compressive strength. The samples produced with 10% paraffin and sintered at 1200 °C showed the best mechanical properties and reached an increase of the compressive strength from 29,00 ± 4,70 MPa before infiltration to 83,00 MPa ± 4,41 after infiltration with PHB for a final porosity of 5%.
- Published
- 2015
- Full Text
- View/download PDF
32. Caracterização mecânica de mangas usando testes de compressão
- Author
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Dantas, Alan Christie da Silva, Barbosa, Romulo, Neto, Acácio Figueiredo, Olivier, Nelson Cárdenas, and Negrin Hernández, Luiz Iván
- Subjects
manga ,mango ,maturation ,mechanical behavior ,módulo de elasticidade ,elasticity modulus ,maturação ,comportamento mecânico - Abstract
O Brasil é um dos maiores produtores de manga e o Vale do São Francisco corresponde por cerca de 87% das exportações brasileiras deste produto para o mercado europeu. O objetivo deste estudo foi caracterizar o comportamento mecânico dos frutos de acordo com os estádios de maturação, a fim de evitar danos físicos causados pelo manejo inadequado do fruto durante a colheita, armazenamento, processamento e transporte. Os testes de compressão foram realizados nas cultivares de manga (Mangifera indicaL.) Keitt e Tommy Atkins em diferentes estádios de maturação para caracterizar o módulo elástico interno e determinar o estresse máximo até a ruptura da manga. Os frutos mostraram diminuição das propriedades mecânicas correlacionadas com o aumento do estádio de maturação, para ambos os cultivares. A variedade Tommy Atkins mostrou melhores propriedades mecânicas, provavelmente relacionadas a uma maior concentração de fibras na polpa, o que resulta em melhor estabilização mecânica., Brazil is one of the largest producers of mangoes, and the São Francisco Valley accounts for about 87 % of Brazilian exports of this product to the European market. This study aimed to characterize the mechanical behavior of the fruits according to the maturation stages, in order to prevent physical damage caused by improper handling of the fruit during harvest, storage, processing and transportation. The compression tests were performed on the mango cultivars (Mangifera indicaL.) Keitt and Tommy Atkins at different maturation stages in order to characterize the internal elastic modulus and determine the maximum stress until rupture of the sleeve. The fruits showed a decrease in mechanical properties correlated with the increase of maturation stage, for both cutivars. The Tommy Atkins variety showed better mechanical properties probably related to a higher concentration of fibers in the pulp which yields better mechanical stabilization.
- Published
- 2017
33. MECHANICAL BEHAVIOUR OF PUMPKIN USING TESTS COMPRESSION
- Author
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Acácio Figueiredo Neto, Heric Cesar Martins Machado, Alan Christie da Silva Dantas, and Nelson Cárdenas Olivier
- Abstract
Os materiais biologicos possuem propriedades elasticas e viscoelasticas, cujo conhecimento torna-se importante para o desenvolvimento de equipamentos e tecnicas adequadas de colheita, transporte e processamento de produtos horticolas. O presente trabalho apresenta os resultados das tensoes transversais maximas que causam a ruptura de abobora (Cucurbita moschata) das variedades leite e jacarezinho, atraves de ensaios mecânicos de compressao axial, evidenciando, dessa forma, quais as cargas maximas que sao capazes de provocar o rompimento das estruturas destes frutos. Foram analisadas as particularidades referentes a geometria das duas variedades de aboboras, realizando-se cortes em suas secoes transversais, para que fossem determinadas as tensoes de flexao e de compressao atuantes nas estruturas rigidas das hortalicas estudadas. Corpos de prova cilindricos, extraidos das polpas das aboboras, foram submetidos a ensaios de compressao axial, com o objetivo de se determinarem os coeficientes de Poisson distintos para ambas as variedades, cujos valores medidos sao 0,50 e 0,46, para as variedades leite e jacarezinho, respectivamente. O Modelo proposto para a analise da fratura nos frutos de abobora mostrou-se compativel com os dados experimentais resultando em um modo de falha por fratura longitudinal ao eixo de aplicacao das cargas. A carga transversal resultante e no minimo 4 vezes maior que a carga maxima de compressao aplicada para ambas as variedades.
- Published
- 2014
- Full Text
- View/download PDF
34. Effect of the Mg2+ Substitution on the Sintering Behavior and Compressive Strength of Doped Β-TCP/CPP Ceramics
- Author
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Alan Christie da Silva Dantas and Wilson Acchar
- Subjects
Materials science ,Mechanical Engineering ,Metallurgy ,Sintering ,Activation energy ,Abnormal grain growth ,Condensed Matter Physics ,Phosphate ,law.invention ,Grain growth ,chemistry.chemical_compound ,Compressive strength ,Chemical engineering ,chemistry ,Mechanics of Materials ,law ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Calcination ,Ceramic - Abstract
β-Tricalcium phosphate (β-TCP) ceramics are of interest for bone requirements implants due to resoption behavior. The mechanical properties of β-TCP, however, are not yet sufficient to allow load bearing application of implants. The aim of this work was to investigate the effect of Mg2+substitution on the strength sintered TCP. Due to promotion of a liquid phase at 1200°C, Calcium pyrophosphate (CPP-C2P2O7) was used to improve the sintering of the samples. The introduction of CPP was promoted by use of a Ca/P molar ratio of 1.45. The powders were synthesized using a mixture of Ca (OH)2suspension and diluted H3PO4with addition of MgO and calcined at 750 °C, 900 °C and 1050 °C. The cold isostatic pressing compacts were sintered at 1200 °C and 1300 °C, respectively.It was shown that a small Mg content (1.5 mol%) increased both compressive strength and fractional density of the TCP material sintered at 1200 °C from 132 ± 39 MPa at 92.1 % of fractional density to 193 ± 29 MPa at 94.5 % of theoretical density. Higher amounts of Mg inhibited the grain growth provoking a increase of the boundary mobility activation energy. Abnormal grain growth (AGG) was observed after sintering at 1300°C, as result CPP - liquid phase formation. Increase of Mg content promoted AGG, due to inhibition of grain growth during normal grain growth resulting in a increase of the residual elastic energy of the system.
- Published
- 2014
- Full Text
- View/download PDF
35. Implications ofBRCA1andBRCA2status for cancer clinical study outcomes
- Author
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David Cameron, Alan Christie, and Charlie Gourley
- Subjects
endocrine system diseases ,business.industry ,Cancer ,General Medicine ,Synthetic lethality ,medicine.disease ,Germline ,Prostate cancer ,Germline mutation ,medicine.anatomical_structure ,Breast cancer ,Prostate ,Pancreatic cancer ,Cancer research ,Medicine ,skin and connective tissue diseases ,business - Abstract
Germline mutations of the BRCA1 and BRCA2 genes are associated with higher risk of breast, ovarian, prostate and pancreatic cancers. Initial conventional treatment is largely the same as for non-BRCA1/2-mutated cancers although there is increasing evidence in a variety of cancer types to suggest that BRCA1 or BRCA2 mutation or inactivation has a role in predicting response to DNA-damaging chemotherapy. The development of PARP inhibitors promises an exciting new therapy in germline BRCA1/2 mutated cancers that directly exploits the genetic mutation. Studies in both germline BRCA1/2 mutation carriers and in platinum-sensitive, high-grade, serous ovarian cancer have demonstrated impressive efficacy when given either as a single agent or maintenance treatment following platinum-based chemotherapy. Initial studies in pancreatic and prostate cancer also suggest significant efficacy. In breast cancer, although efficacy has been demonstrated, the optimal patient population remains to be defined.
- Published
- 2014
- Full Text
- View/download PDF
36. GAINS IN PERFORMANCE OF DIESEL CYCLE ENGINE USING B10 COMPARED TO OTHER MIXTURES
- Author
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Guimarães, Camila Coelho, primary, Santos, Vivianni Marques Leite dos, additional, Dantas, Alan Christie da Silva, additional, Cortez, Jorge Wilson, additional, and Pereira, Paulo José, additional
- Published
- 2018
- Full Text
- View/download PDF
37. Development and implementation of a service for patients with cancer of unknown primary
- Author
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Lucy Wall, Carolyn Bedi, Lesley Dawson, Melanie Mackean, Ewan Brown, Gillian Knowles, Sally Clive, and Alan Christie
- Subjects
Service (business) ,medicine.medical_specialty ,Cancer of unknown primary ,Referral ,business.industry ,Emergency medicine ,medicine ,General Medicine ,Medical emergency ,Disease management (health) ,medicine.disease ,business ,Hospital stay - Published
- 2013
- Full Text
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38. Effect of CO32−Incorporation on the Mechanical Properties of Wet Chemically Synthesized β-Tricalcium Phosphate (TCP) Ceramics
- Author
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Peter Greil, Alan Christie da Silva Dantas, and Frank A. Müller
- Subjects
Materials science ,Scanning electron microscope ,Sintering ,Mineralogy ,Phosphate ,law.invention ,chemistry.chemical_compound ,Compressive strength ,chemistry ,law ,visual_art ,Ultimate tensile strength ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Calcination ,Ceramic ,Porosity ,Nuclear chemistry - Abstract
Calcium-deficient hydroxyapatite (CDHA) powders were synthesized by a wet chemical precipitation method using Ca(OH)2 and H3PO4 solutions. Single-phase β-tricalcium phosphate (β-TCP) powder with a molar (Ca+Mg)/P ratio of 1.5 was obtained after calcination of CDHA synthesized under vacuum. During synthesis in air, CO2 can be adsorbed and HBO42− is partly substituted by CO32−, resulting in a lower phosphorous content and consequently an increase of the molar (Ca+Mg)/P ratio to 1.53. A two-phase β-TCP powder containing 20 wt% hydroxyapatite (HA) was obtained after calcination. Samples prepared from β-TCP powders synthesized under vacuum achieved a compressive strength of 301±23 MPa at 99.6% fractional density, while TCP/HA samples prepared in air achieved a maximum compressive strength of 132±29 MPa at 91.7% fractional density. This decrease in strength can be correlated to the porosity retaining due to CO2 release during sintering and residual tensile stresses in the TCP matrix caused by the thermal expansion mismatch of β-TCP and HA.
- Published
- 2008
- Full Text
- View/download PDF
39. Mechanical characterization of mango fruit using compression tests
- Author
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Dantas, Alan Christie da Silva, primary, Barbosa, Romulo, additional, Neto, Acácio Figueiredo, additional, Olivier, Nelson Cárdenas, additional, and Negrin Hernández, Luiz Iván, additional
- Published
- 2017
- Full Text
- View/download PDF
40. Influence of Mg-substitution on the physicochemical properties of calcium phosphate powders
- Author
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Alan Christie da Silva Dantas, Peter Greil, Juliana Marchi, Ana Helena A. Bressiani, José Carlos Bressiani, and Frank A. Müller
- Subjects
Materials science ,Annealing (metallurgy) ,Mechanical Engineering ,Analytical chemistry ,Sintering ,Mineralogy ,Crystal structure ,Condensed Matter Physics ,Microstructure ,law.invention ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,law ,X-ray crystallography ,General Materials Science ,Calcination ,Phosphoric acid ,Magnesium ion - Abstract
Tricalcium phosphate based ceramics (TCP) are bioresorbable and thereby considered to be promising bone replacement materials. The differences in crystal structure between {alpha} and {beta}-TCP phases gives rise for different dissolution rates in vitro and in vivo, which may alter the bioresorbable behavior of TCP ceramics. It is suggested that the addition of magnesium ions, which are also present in biological tissues, stabilizes {beta}-phase to higher temperatures and thus enables the sintering of {beta}-TCP at elevated temperatures compared to Mg free TCP. In this paper, Mg-substituted TCP, with the general formula (Ca{sub 1-x}Mg {sub x}){sub 3}(PO{sub 4}){sub 2} and 0.01 {
- Published
- 2007
- Full Text
- View/download PDF
41. Acaricidal activity of extracts from the leaves and aerial parts of Neoglaziovia variegata (Bromeliaceae) on the cattle tick Rhipicephalus (Boophilus) microplus
- Author
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Jackson Roberto Guedes da Silva Almeida, Sarah Raquel Gomes de Lima-Saraiva, M.C. Horta, D.M.R. Machado, A.C. Araujo, Raimundo G. Oliveira-Junior, Alan Christie da Silva Dantas, and Luciano Augusto de Araújo Ribeiro
- Subjects
Bromeliaceae ,Veterinary medicine ,Ethyl acetate ,chemistry.chemical_compound ,parasitic diseases ,Botany ,Rhipicephalus ,Animals ,Acaricides ,General Veterinary ,biology ,Acaricide ,business.industry ,Plant Extracts ,fungi ,Pest control ,Pesticide ,biology.organism_classification ,Fecundity ,Plant Leaves ,Distilled water ,chemistry ,Female ,business - Abstract
This experiment was carried out to study the bioacaricidal activity of Neoglaziovia variegata against engorged females of Rhipicephalus (Boophilus) microplus. The mortality and fecundity of groups of engorged adult females exposed to different concentrations of ethanol, hexane, chloroform, and ethyl acetate extracts obtained from the leaves and aerial parts of N. variegata were evaluated, using three treatments with concentrations of 5, 10 e 25 mg/ml; two controls (distilled water and distilled water with drops of cremophor); with three replicates. The hexane extract of the leaves demonstrated significant results, presenting 94.1% inhibition of oviposition; 0.33% the average percentage of eclosion of eggs; and 99.8% of effectiveness. These results indicate N. variegata, particularly the hexane extract of leaves, as potential alternative control agents of R. (B.) microplus. Pharmacological and chemical studies are continuing in order to characterize the mechanism responsible for this effect.
- Published
- 2014
42. Production of Single-Phase Hydroxyapatite Porous Bodies from Gypsum/Polystyrene
- Author
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Barbosa, Amanda A., primary, Ferraz, Andrea V., additional, Santos, Geciane A., additional, Olivier, Nelson C., additional, and Dantas, Alan Christie Silva, additional
- Published
- 2016
- Full Text
- View/download PDF
43. Dermatomyositis as presenting feature of ovarian cancer, treated with neo-adjuvant chemotherapy and interval debulking surgery
- Author
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Fiona Nussey, Alan Christie, and Neil McKay
- Subjects
myalgia ,Chemotherapy ,medicine.medical_specialty ,endocrine system ,endocrine system diseases ,business.industry ,medicine.medical_treatment ,Obstetrics and Gynecology ,Case Report ,Neo-adjuvant chemotherapy ,Dermatomyositis ,Debulking ,medicine.disease ,female genital diseases and pregnancy complications ,Surgery ,Oncology ,Anterior chest ,Ovarian cancer ,Maculopapular rash ,medicine ,medicine.symptom ,Myopathy ,business - Abstract
IntroductionDermatomyositis is a rare, idiopathic, inflammatory myopathy withreported incidences varying from 0.5–0.89 per 100,000 (Robinson andReed, 2011). There is a well documented relationship with malignan-cies such as breast, lung or ovarian cancer (Sigurgeirsson et al., 1992;Hilletal.,2001)andithaspreviouslybeenreportedasapresentingfea-ture of ovarian cancer. However, previous reports in ovarian cancer areof cases treated with primary de-bulkingsurgery. Webelieve this to bethe first report of a case treated with neo-adjuvant chemotherapy andinterval debulking surgery.CaseA 57 year old Caucasian lady presented to her General Practitionerwith a pruritic rash on her anterior chest, upper arms, hands and face.Two weeks later proximal myalgia and stiffness of all four limbs de-veloped and a dermatology opinion was sought. On physical exami-nation there was an erythematous maculopapular rash affecting the
- Published
- 2013
44. Níveis de potência sonora emitidos por trator agrícola em condições estáticas e dinâmicas
- Author
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Hideo de Jesus Nagahama, Fernanda Rodrigues Lima da Costa, Alan Christie da Silva Dantas, Jorge Wilson Cortez, and Aline Dantas da Silva Alves
- Subjects
Tractor ,ergonomia ,business.product_category ,Soil test ,Agricultural machinery ,business.industry ,Acoustics ,Ruído ,Rotational speed ,mecanização agrícola ,Sound power ,Noise ,Metre ,business ,Agronomy and Crop Science ,Rotation (mathematics) ,Mathematics - Abstract
O ruído das máquinas agrícolas, com o passar do tempo, pode provocar problemas auditivos em seus operadores. O objetivo deste trabalho foi avaliar o nível de potência sonora emitido por trator agrícola, em condições estáticas e dinâmicas, comparando-o às normas IEC651 e IEC61672. O trabalho foi realizado na Universidade Federal do Vale do São Francisco, Petrolina (PE), em 2009, utilizando-se um trator Valtra, modelo 785 TDA sem cabine, e medidores do nível de potência sonora. As medições foram: estática (posições anterior, posterior, direita e esquerda do assento do operador a cada metro, até a distância máxima de 10 m, e diferentes rotações do motor, com dois equipamentos de medição) e dinâmica (cinco velocidades de deslocamento, em pista de concreto e terra batida, utilizando-se dois equipamentos de medição). Para os equipamentos que atendem às normas IEC651 e IEC61672, o segundo sempre apresentou maiores valores do nível de potência sonora, devido ao primeiro ser utilizado com protetor de vento. Em todas as condições, o nível de potência sonora foi maior do que o permitido pela legislação. À medida que se aumenta a rotação do motor, ocorre incremento no nível de potência sonora. Verificou-se que as pistas de terra batida e concreto podem ser utilizadas para análise do nível de potência sonora, devido aos resultados similares apresentados. A velocidade de deslocamento do trator influenciou no nível de potência sonora, sendo que as marchas mais longas apresentaram maiores valores.
- Published
- 2011
45. Níveis de potência sonora emitidos por trator agrícola em condições estáticas e dinâmicas
- Author
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Alves, Aline Dantas da Silva, Costa, Fernanda Rodrigues Lima da, Cortez, Jorge Wilson, Dantas, Alan Christie da Silva, and Nagahama, Hideo de Jesus
- Subjects
ergonomia ,ergonomics ,Ruído ,mecanização agrícola ,Noise ,agricultural mechanization - Abstract
O ruído das máquinas agrícolas, com o passar do tempo, pode provocar problemas auditivos em seus operadores. O objetivo deste trabalho foi avaliar o nível de potência sonora emitido por trator agrícola, em condições estáticas e dinâmicas, comparando-o às normas IEC651 e IEC61672. O trabalho foi realizado na Universidade Federal do Vale do São Francisco, Petrolina (PE), em 2009, utilizando-se um trator Valtra, modelo 785 TDA sem cabine, e medidores do nível de potência sonora. As medições foram: estática (posições anterior, posterior, direita e esquerda do assento do operador a cada metro, até a distância máxima de 10 m, e diferentes rotações do motor, com dois equipamentos de medição) e dinâmica (cinco velocidades de deslocamento, em pista de concreto e terra batida, utilizando-se dois equipamentos de medição). Para os equipamentos que atendem às normas IEC651 e IEC61672, o segundo sempre apresentou maiores valores do nível de potência sonora, devido ao primeiro ser utilizado com protetor de vento. Em todas as condições, o nível de potência sonora foi maior do que o permitido pela legislação. À medida que se aumenta a rotação do motor, ocorre incremento no nível de potência sonora. Verificou-se que as pistas de terra batida e concreto podem ser utilizadas para análise do nível de potência sonora, devido aos resultados similares apresentados. A velocidade de deslocamento do trator influenciou no nível de potência sonora, sendo que as marchas mais longas apresentaram maiores valores. The noise produced by farm machinery may cause hearing problems to its operators along the time. The objective of this study was to evaluate the sound power level emitted by agricultural tractor under static and dynamic conditions, in relation to the IEC651 and IEC61672 norms. It was conducted at the Universidade Federal do Vale do São Francisco, in Petrolina, Pernambuco State, Brazil, in 2009, by using a Valtra 785 TDA tractor without cabin and equipment to measure its sound power level. The measurements were: static (anterior, posterior, right, and left positions, in relation to the operator’s seat, for each meter along the maximum distance of 10 m, and different engine rotation speeds, with two measuring devices) and dynamic (five speeds on concrete and soil test tracks, with two devices). Two measurement devices were used to evaluate the sound power level. For the devices in accordance with the IEC651 and IEC62672 norms, the second one always presented higher sound power levels, due to the fact that the first one was equipped with a wind protector. In all positions, the sound power level was higher than allowed by law. As the engine rotation speed increases, the sound power level also increases. It was noticed that both test tracks can be used for sound power level analysis, due to their similar results. The tractor speed affected its sound power level, with higher values for longer gears.
- Published
- 2011
46. Production of Hydroxyapatite/Polyhydroxibutirate Based Composites for Biomaterials Applications
- Author
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Santos, Geciane A., primary, Dantas, Alan Christie Silva, additional, Oliveira, Leticia M., additional, Ferraz, Andrea V., additional, Acchar, Wilson, additional, and Olivier, Nelson C., additional
- Published
- 2015
- Full Text
- View/download PDF
47. Modeling of Two-Dimensional Orthotropic Heat Conduction in Porous Gypsum
- Author
-
Souza, Carlos R.N., primary, Alencar, José P., additional, Dantas, Alan Christie Silva, additional, Ferraz, Andrea V., additional, and Olivier, Nelson C., additional
- Published
- 2015
- Full Text
- View/download PDF
48. Mechanical Properties of Mg substituted ß-tricalcium phosphate bioceramics
- Author
-
Dantas, Alan Christie da Silva
- Subjects
Biokeramik ,ddc:620 ,Technische Fakultät -ohne weitere Spezifikation - Abstract
ß-TCP und Mg-dotiertes ß-TCP wurden durch nasschemische Fällungsreaktion aus Calciumnitrat und Di-Ammoniumhydrogenphosphat hergestellt. Der Effekt von Reifungszeit, pH-Wert und Mg-Anteil auf das resultierende molare (Ca+Mg)/P Verhältnis und die Phasenzusammensetzung wurde analysiert. Mg-Dotierung führt zur Produktion von ß-TCP Mischkristall-Pulvern, aus denen vollständig verdichtete Keramikkörper mit verbesserten mechanischen Eigenschaften hergestellt werden können. Mit 1 Mol-% Mg dotiertem ß-TCP wird eine Sinterdichte von ca. 99% und Biegefestigkeiten von über 125 MPa erreicht. Die Erhöhung der Mg-Dotierung führt ebenfalls zu einer Steigerung der Bruchzähigkeit von 0.65 0.05 MPam-1/2 auf 1.14 0.04 MPam-1/2 für mit 1 Mol-% Mg dotiertem ß-TCP. Der Einbau von Mg2+ führt zu niedrigeren Löslichkeitsraten in wässriger Lösung im Vergleich zu b-TCP. Die mechanischen Eigenschaften nach Auslagerung in wässriger Lösung werden durch Bildung von Oberflächerissen reduziert, wobei b-TCP eine transkristalline Rissbildung und Mg-dotierte ß-TCP Mischkristall eine interkristalline Rissbildung zeigt. Die Synthese bei pH-Werten von unter 8.5 führt zur Bildung von ß-CPP als Sekundärphase, die einen negativen Einfluss auf die mechanischen Eigenschaften hat. Synthesen bei pH 8.5 und Reifungszeiten von länger als 24 h produzierten zweiphasige Pulver mit ca. 5 Masse-% HA als Sekundärphase. Die Anwesenheit von HA in einer ß-TCP Matrix begünstigt die Bildung von Zugspannungen in der Matrix und eine Abnahme der Bruchfestigkeit und Bruchzähigkeit. Für den umgekehrten Fall, bei dem die Matrix aus HA und die Partikel aus ß-TCP sind, ist eine Erhöhung der Bruchzähigkeit und der Bruchfestigkeit zu erwarten. ß-TCP and Mg substituted ß-TCP were synthesized by chemical reaction of Calcium nitrate and Di-ammoniumhydrogenphosphate. The effect of ripening time, pH and Mg amount on the phase composition of the powders was studied. Mg addition produces powders which can be used to manufacture dense ceramic bodies with increased mechanical properties. 1 mol-% Mg doted samples reaches a relative density of 99% and flexural strength of 126 MPa. Increase of the fracture toughness from 0.65 0.05 MPam-1/2 up to 1.14 0.04 MPam-1/2 is also caused by 1 Mol-% Mg substitution. The Mg substitution leads to lower solubility rates in aqueous solutions. The mechanical properties are reduced after soaking in water, due to formation of cracks at the surface. -TCP shows a transcrystalline crack formation and Mg-substituted TCP shows an intercrystalline crack formation. Single phase ß-TCP can only be synthesized by a controlled pH of 8.5 and after a ripening time of 5 h. Longer times and lower pH lead to formation of biphasic ceramics with reduced mechanical properties due to a negative effect of the second phase into the ß-TCP matrix. Residual stress is produced by the mismatch between the HA inclusions and the ß-TCP matrix. An increase of the mechanical strength and fracture toughness are expected for ß-TCP reinforced HA.
- Published
- 2009
49. MECHANICAL BEHAVIOUR OF PUMPKIN USING TESTS COMPRESSION
- Author
-
Dantas, Alan Christie da Silva, primary, Olivier, Nelson Cardenas, additional, FIGUEIREDO NETO, Acácio, additional, and Machado, Heric Cesar Martins, additional
- Published
- 2014
- Full Text
- View/download PDF
50. Effect of the Mg2+ Substitution on the Sintering Behavior and Compressive Strength of Doped Β-TCP/CPP Ceramics
- Author
-
Dantas, Alan Christie Silva, primary and Acchar, Wilson, additional
- Published
- 2014
- Full Text
- View/download PDF
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