10,284 research outputs found
Implications of the Improvement of Teaching Quality for Professional Development (PD) of Academics at the Colleges of Applied Sciences (CASs) in the Sultanate of Oman
No full textThe Oman Accreditation Council (OAC), which is called later the Oman Academic Accreditation Authority (OAAA), designed a higher education institution (HEI) Quality Assurance (QA) framework for Omani public and private Higher Education Institutions (HEIs), starting with a quality audit process in 2008. The Colleges of Applied Sciences (CASs), as a public HEI, are required to ensure the quality of all services and activities to meet particular national standards (specified in the framework) in order to gain a HEI and programme certificate. In line with a quality audit scope, the quality of the fields of PD and related teaching quality should be ensured and enhanced by the promotion and contribution of the former field to the maintenance and improvement of the latter one.
The chief purpose of this study was to identify the uptake and implications of the growing requirement to improve teaching quality and the PD of academics at the CASs in the Sultanate of Oman especially in the context of the application of the QA framework. The study focused on examining the academics’ participation in professional development programmes (PDPs) and current perceptions of PD with respect to the improvement of teaching quality improvement at these colleges. The current study also dealt with a reorganization and prioritization of academics’ PD needs, barriers to effective PD, and factors to enhance PD of academics regarding teaching quality improvement in the colleges.
Based on the purpose and research objectives, the current study adopted both positivist (quantitative) and interpretive (qualitative) research paradigms. Because the study perused quantitative and qualitative data regarding certain variables, it chose a mixed-research design. The researcher designed survey questionnaire to collect quantitative data and a semi-structured interview and a focus group discussion to probe and interpret quantitative findings. After fulfillment of the validity and reliability measurements, a self-completion questionnaire was distributed to a stratified random sample of academics (170) over the six CASs. A total of 150 questionnaires (out of 170) were completed and returned and the response-rate reached 88.2%. The quantitative data was analyzed by appropriate analysis using the Statistical Package for Social sciences (SPSS), while the qualitative data was analyzed by appropriate qualitative analysis.
The findings of the study showed that the level of academics’ participation in PDPs to improve teaching quality in the last two years in the CASs seems to be unsatisfactorily low. The current perceptions of the PD situations in the colleges, relating to teaching quality improvement, signified a shortage in the number of available PDPs and/or a discouragement of academics’ participation in these programmes in the last two years. The study also revealed all the 22 PD needs of academics regarding the improvement of teaching quality are significantly demanded by participants; the higher rated needs focused on a development of ‘student centred’ skills, such as critical thinking and problem-solving skills.
Furthermore, the study illustrated that the highest significant perceived barriers to effective PD in the CASs, as related to teaching quality improvement, focus on a lack of a clear institutional PD policy and a lack of appropriately systematic PD plans. The study also revealed all 10 perceived factors to enhance PD regarding teaching quality improvement are very important. The most significant factors represented and stressed particular problematic issues (the high rated barriers) and a reduction of a heavy workload to enhance academics’ participation in PD regarding the improvement of teaching quality.
Conclusions drawn from the discussion of the findings of study include a lack of a clear PD policy at national and institutional levels and absence of a particular authority/unit concerning PD issues in Omani HEIs. The two problematic issues resulted in a lack of systematic and realistic PD plans in the CASs, involving a lack of academics’ involvement in PD plans, a misconnection of academics’ PD needs to PD, inappropriate facilities and resources allocation, and inappropriate evaluation processes of PD. In addition, the conclusions also include that PD of academics regarding the improvement of teaching quality in the colleges requires more attention and focus to manage particular significant issues perceived by participants as both barriers and potential facilitators relating to PD of academics.
Based on identified conclusions, particular implications for policy and practice to enhance PD to improve teaching quality were set at three levels: governmental, institutional, and individual. Moreover, achievements of the current study according to the research questions were identified and contributions of the study to the fields of PD, teaching quality, and the context of QA and quality audit in HE were addressed. Based on the findings and conclusions, particular directions and recommended issues were suggested to be studied by further research to benefit the enhancement of PD and related teaching quality improvement
Proprieta' fisiche della materia
No full textQuesto libro vuole servire da introduzione al tema complesso delle proprieta' fisiche della materia. La prima parte del testo e' dedicata a tracciare origini, riassumere i concetti e descrivere i fondamenti della meccanica quantistica. La seconda parte del libro affronta il tema principale e discute le proprieta' elettriche, magnetiche, ottiche e termiche della materia solida. Per completare vengono discussi i cristalli liquidi
Fullerene-like WS<sub>2</sub> supported Pd catalyst for hydrogen evolution reaction
No full textHydrogen is the most desirable green energy carrier and electrocatalytic hydrogen evolution reaction (HER) from water is a promising route for hydrogen production. The search for efficient, low-cost HER catalysts is a challenging and attracting topic. In this work, we report that inorganic fullerene-like WS2 supported Pd nanoparticles (Pd/WS2), with Pd loading of 0.76 wt%, are active for electrocatalytic HER conducted in 0.5 M H2SO4 solution, with overpotential at 10 mA cm−2 current density of ~130 mV and Tafel slope of 82.4 mV dec−1, which is comparable to that of Pt/WS2 (0.88 wt% Pt loading) with higher costs. Characteristic results indicate that WO3 impurities were in-situ produced on the WS2 surface and the Pd NPs are primarily located inside the WS2 nanocages. Contrasting experiments suggest that the WO3 impurities play a crucial role in generating Hads intermediate and the Pd NPs are active sites of H2 production, and a reaction mechanism is proposed. The Pd/WS2 catalyst also shows good long-term stability owing to the location of Pd NPs inside the WS2 cages. The high HER activity, low costs and good stability make the Pd catalyst a potential alternative to Pt catalyst for HER.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Micro and Nano Engineerin
Enhanced T-Cell Immunity to Osteosarcoma Through Antibody Blockade of PD-1/PD-L1 Interactions
No full textabstract: Osteosarcoma is the most common bone cancer in children and adolescents. Although 70% of patients with localized disease are cured with chemotherapy and surgical resection, patients with metastatic osteosarcoma are typically refractory to treatment. Numerous lines of evidence suggest that cytotoxic T lymphocytes (CTLs) limit the development of metastatic osteosarcoma. We have investigated the role of PD-1, an inhibitory TNFR family protein expressed on CTLs, in limiting the efficacy of immune-mediated control of metastatic osteosarcoma. We show that human metastatic, but not primary, osteosarcoma tumors express a ligand for PD-1 (PD-L1) and that tumor-infiltrating CTLs express PD-1, suggesting this pathway may limit CTLs control of metastatic osteosarcoma in patients. PD-L1 is also expressed on the K7M2 osteosarcoma tumor cell line that establishes metastases in mice, and PD-1 is expressed on tumor-infiltrating CTLs during disease progression. Blockade of PD-1/PD-L1 interactions dramatically improves the function of osteosarcoma-reactive CTLs in vitro and in vivo, and results in decreased tumor burden and increased survival in the K7M2 mouse model of metastatic osteosarcoma. Our results suggest that blockade of PD-1/PD-L1 interactions in patients with metastatic osteosarcoma should be pursued as a therapeutic strategy.This is a non-final version of an article published in final form as Lussier, Danielle M., O'Neill, Lauren, Nieves, Lizbeth M., McAfee, Megan S., Holechek, Susan A., Collins, Andrea W., Dickman, Paul, Jacobsen, Jeffrey, Hingorani, Pooja, & Blattman, Joseph N. (2015). Enhanced T-Cell Immunity to Osteosarcoma Through Antibody Blockade of PD-1/PD-L1 Interactions. JOURNAL OF IMMUNOTHERAPY, 38(3), 96-106. http://dx.doi.org/10.1097/CJI.000000000000006
Modeling of Surface Segregation for Binary Alloys in Vacuum and Gas Environments: Applied to Pd-alloys
No full textComputational modeling offers the possibility to design alloys in a cheaper and faster way. A model for surface segregation for binary alloys in vacuum and by adsorption and absorption of gases was developed and applied. The proposed model was used in conjunction with the Miedema semi-empirical model for the calculation of enthalpies of solution and formation of binary alloys and with the cluster variation method (CVM) for the calculation of the ? and ? phase boundaries in the ternary Pd-M-H systems. The models for segregation were applied in a temperature range from 298K to 600K, considering the surface plane (111) of the FCC crystal structure. The model for segregation in vacuum was applied to Pd-Au, Pd-Ag, Pd-Cu, Pd-Ni and Pd-Pt. For this case Pd is segregated for the Pd-Pt alloys only. By increasing the temperature from 298K to 600K, the surface concentrations of Pd decreased for all of the alloys. By varying the plane from (111) to (100) few changes were observed. The calculated results compared to experiments were found to be in good agreement for Pd-Au and Pd-Ag. For the model of surface segregation by adsorption and chemisorption, H2, CO and O2 gases on Pd-Ag, Pd-Cu, Pd-Ni and Pd-Pt were considered. In the presence of adsorbed or chemisorbed hydrogen, segregation of Pd was found for Pd-Ag, Pd-Cu and Pd-Pt alloys. For adsorbed O2 and CO on Pd-Ag and Pd-Cu alloys gases, segregation of Pd was enhanced. The model for segregation by absorption of hydrogen was applied for Pd-Ag, Pd-Cu, Pd-Ni and Pd-Pt alloys, using a hydrogen (bulk) concentration of 0.50 H/M. No Pd segregation was found for Pd-Ag alloys. For Pd-Pt alloys, Pd segregation was observed. For Pd-Cu alloys with large concentrations of Pd, a surface enrichment of Pd was calculated, while for alloys with low concentration of Pd a slight Cu surface enrichment was observed. Enhanced segregation of Ni was found for Pd-Ni alloys. The H/M fractions at the boundaries of the ? and ? phase obtained with the CVM for the Pd85Ag15H system were used as input values to calculate the surface concentration of Ag. As the hydrogen concentration was increased, the surface segregation of Pd also increased. For the surface segregation by adsorption and absorption combined, segregation of Pd was observed for Pd-Ag, Pd-Cu and Pd-Pt alloys. Surface enrichment of Ni was found for Pd-Ni alloys. The proposed model enables to predict surface segregation under various conditions and the results show that it is affected by many parameters.Master Materials Science and EngineeringDepartment of Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
Performação simbólica da nação portuguesa: Ada de Castro e o Culto Fadista de Lisboa
No full textEsta tese explora detalhes da utilização da categoria musical fado como instrumento de
poder. Sublinha em particular a reutilização de modelos românticos que perpetuam, hoje ainda,
noções de portugalidade. O estudo etnomusicológico centrado em Ada de Castro, fadista
emérita lisboeta que serviu o Estado Novo nas décadas de 1960 e 1970, sobretudo reincarnando
Maria Severa, e celebrou o cinquentenário da sua carreira profissional em 2010, revela
situações inéditas, à margem da historiografia mainstream do fado. Entre as categorias de
análise propostas, a das cativações através de representações mediáticas de produtos do fado,
exprime marcos significativos da construção identitária nacionalista portuguesa. O quadro
teórico, na perspetiva etnosimbólica dos estudos de nacionalismo de Anthony D. Smith, cruza
cinco dos seus conceitos-chave – recursos simbólicos, la longue durée, elitismo, etnicidade e
conflito e reinterpretação – com tropos de património e memória da simbologia da nação
portuguesa. Este trabalho, fruto de uma etnografia colaborativa intensa, de seis anos de
pesquisa de campo, de uma década de vivência performativa do fado nos bairros antigos de
Lisboa, e de consulta exaustiva de uma série de periódicos antigos, entre a bibliografia da
especialidade, contribui para a compreensão documentada do papel do fado como recurso
simbólico emocionalmente poderoso. O seu objetivo é desconstruir anacronismos, moldando
resquícios da velha consciência nacional, que assolam ainda uma parte significativa da
cidadania portuguesa.This thesis delves into the intricate use of the musical category of fado as a tool of
power. It highlights the ongoing perpetuation of romanticized models that still shape notions
of Portuguese identity today. The ethnomusicological study focuses on Ada de Castro, a
renowned Lisbon-based fadista who served the Estado Novo regime during the 1960s and
1970s, especially through her reincarnation of Maria Severa. In 2010, Ada de Castro celebrated
fifty years of her professional career, marking a significant moment in the history of fado. This
research uncovers previously undocumented situations that remain on the fringes of
mainstream fado historiography. Among the categories of analysis, the concept of cativações
(captivations) through media representations of fado products highlights key moments in the
construction of Portuguese nationalist identity. The theoretical framework employs Anthony
D. Smith's ethnosymbolic approach to nationalism studies, intersecting five of his key concepts
– symbolic resources, la longue durée, elitism, ethnicity, and conflict and reinterpretation –
with heritage and memory tropes associated with Portuguese national symbolism. This work is
the result of six years of intense collaborative ethnography, extensive fieldwork, and over a
decade of performance experience in Lisbon's old neighborhoods. It also draws on a thorough
consultation of a series of historical periodicals, along with specialized bibliography,
contributing to a well-documented understanding of fado's role as a symbolically and
emotionally powerful resource. Furthermore, the thesis seeks to deconstruct the anachronisms
that continue to shape remnants of old national consciousness, which still resonate in
significant aspects of Portuguese citizenship today
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Novel fuzzy logic controllers with self-tuning capability
No full textTwo controllers which extend the PD+I fuzzy logic controller to deal with the plant having time varying nonlinear dynamics are proposed. The adaptation ability of the first self tuning PD+I fuzzy logic controller (STPD+I_31) is achieved by adjusting the output scaling factor automatically thereby contributing to significant improvement in performance. Second controller (STPD+I_9) is the simplified version of STPD+I_31 which is designed under the imposed constraint that allows only minimum number of rules in the rule bases. The proposed controllers are compared with two classical nonlinear controllers: the pole placement self tuning PID controller and sliding mode controller. All the controllers are applied to the two-links revolute robot for the tracking control. The tracking performance of STPD+I_31 and STPD+I_9 are much better than the pole placement self tuning PID controller during high speed motions while the performance are comparable at low and medium speed. In addition, STPD+I_31 and STPD+I_9 outperform sliding mode controller using same method of comparison study
Partial Discharge Detection in High-Voltage Gas Insulated Switchgear Using Fiber Optic Based Acoustic Sensors
No full textPartial discharges (PD) are small current pulses that can occur within the insulation of medium and high voltage (HV) electrical assets such as cable accessories, transformers and switchgear. In GIS units, PD's can occur near the high-voltage conductor or at other locations commonly due to metallic particles from the erosion of the switchgear contacts or left behind after maintenance. For that reason, GIS units are usually equipped with multiple embedded UHF sensors in selected compartments that can detect PD in their vicinity. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ESP LA
High-resolution LMN and LMM Auger spectra of Pd, Ag, In, Sn and Sb
No full textFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSConsiderable interest in high-resolution Auger spectroscopy of the 4d metals has arisen because of the possibility of treating Auger spectroscopy as an excited state probe in order to extract new information regarding electronic structure. Auger transitions involving only core levels are interesting because current theories of line shapes and energies usually assume that the final core holes are either atomic or quasi-atomic. Comparison of the results of atomic calculations with experimental Auger spectra comprises a crucial test of the atomic theories. We present the results of high-resolution measurements of several high energy LMN and LMM Auger spectra of Pd, Ag, In, Sn and Sb excited with Ti Kα radiation. Assignments of the peaks are based upon energy and intensity considerations. We compare the experimental spectra with the results of atomic transition probability calculations, which indicates the reliability of such calculations as we proceed from open to closed 4d shell metals. © 1998 Elsevier Science B.V. All rights reserved.Considerable interest in high-resolution Auger spectroscopy of the 4d metals has arisen because of the possibility of treating Auger spectroscopy as an excited state probe in order to extract new information regarding electronic structure. Auger transitions involving only core levels are interesting because current theories of line shapes and energies usually assume that the final core holes are either atomic or quasi-atomic. Comparison of the results of atomic calculations with experimental Auger spectra comprises a crucial test of the atomic theories. We present the results of high-resolution measurements of several high energy LMN and LMM Auger spectra of Pd, Ag, In, Sn and Sb excited with Ti K? radiation. Assignments of the peaks are based upon energy and intensity considerations. We compare the experimental spectra with the results of atomic transition probability calculations, which indicates the reliability of such calculations as we proceed from open to closed 4d shell metals.Considerable interest in high-resolution Auger spectroscopy of the 4d metals has arisen because of the possibility of treating Auger spectroscopy as an excited state probe in order to extract new information regarding electronic structure. Auger transitions involving only core levels are interesting because current theories of line shapes and energies usually assume that the final core holes are either atomic or quasi-atomic. Comparison of the results of atomic calculations with experimental Auger spectra comprises a crucial test of the atomic theories. We present the results of high-resolution measurements of several high energy LMN and LMM Auger spectra of Pd, Ag, In, Sn and Sb excited with Ti Kα radiation. Assignments of the peaks are based upon energy and intensity considerations. We compare the experimental spectra with the results of atomic transition probability calculations, which indicates the reliability of such calculations as we proceed from open to closed 4d shell metals.7. International Conference on Electron Spectroscopy943253257FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSSem informaçãoSem informaçãoSem informaçãoFuggle, J.C., (1981) Electron Spectroscopy, p. 85. , C.R. Brundle and A.D. Baker (Eds.), Academic Press, LondonWeightman, P., (1982) Rep. Prog. 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Metrological Qualification of PD Analysers for Insulation Diagnosis of HVDC and HVAC Grids
No full textOn-site partial discharge (PD) measurements have turned out to be a very efficient technique for determining the insulation condition in high-voltage electrical grids (AIS, cable systems, GIS, HVDC converters, etc.); however, there is not any standardised procedure for determining the performances of PD measuring systems. In on-line and on-site PD measurements, high-frequency current transformers (HFCTs) are commonly used as sensors as they allow for monitoring over long distances in high-voltage installations. To ensure the required performances, a metrological qualification of the PD analysers by applying an evaluation procedure is necessary. A novel evaluation procedure was established to specify the quantities to be measured (electrical charge and PD repetition rate) and to describe the evaluation tests considering the measured influence parameters: noise, charge amplitude, pulse width and time interval between consecutive pulses. This procedure was applied to different types of PD analysers used for off-line measurements, sporadic on-line measurements and continuous PD monitoring. The procedure was validated in a round-robin test involving two metrological institutes (RISE from Sweden and FFII from Spain) and three universities (TUDelft from the Netherlands, TAU from Finland and UPM from Spain). With this round-robin test, the effectiveness of the proposed qualification procedure for discriminating between efficient and inappropriate PD analysers was demonstrated. Furthermore, it was shown that the PD charge quantity can be properly determined for on-line measurements and continuous monitoring by integrating the pulse signals acquired with HFCT sensors. In this case, these sensors must have a flat frequency spectrum in the range between several tens of kHz and at least two tens of MHz, where the frequency pulse content is more significant. The proposed qualification procedure can be useful for improving the future versions of the technical specification TS IEC 62478 and the standard IEC 60270.High Voltage Technology Grou
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