302 resultados para Field assisted sintering technique


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Navigational safety analysis relying on collision statistics is often hampered because of low number of observations. A promising alternative approach that overcomes this problem is proposed in this paper. By analyzing critical vessel interactions this approach proactively measures collision risk in port waters. The proposed method is illustrated for quantitative measurement of collision risks in Singapore port fairways, and validated by examining correlations between the measured risks with those perceived by pilots. This method is an ethically appealing alternative to the collision-based analysis for fast, reliable and effective safety assessment, thus possesses great potential for managing collision risks in port waters.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"The research presented in this volume has been undertaken in a range of settings and across ages, to display the rich, varied, and complex aspects of children and young people's everyday lives. The papers contribute to understanding children's disputes, framed as forms of social practice, by closely examining children's talk and interaction in disputes to offer insight into how they arrange their social lives within the context of school, home, neighborhood, correctional, and cafe settings. As such, this volume contributes to an emerging body of edited volumes that investigate children and young people's everyday interactions (Cromdal, 2009; Cromdal & Tholander, in press; Gardner & Forrester, 2010; Goodwin & Kyratzis, 2007; Hutchby & Moran-Ellis, 1998). Each paper has been peer reviewed, by respected researchers of the field, in some cases authors of this volume, and revised. We also thank Charlotte Cobb-Moore who so ably assisted in the final preparation of the manuscripts."---publisher website

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Current concerns regarding terrorism and international crime highlight the need for new techniques for detecting unknown and hazardous substances. A novel Raman spectroscopy-based technique, spatially offset Raman spectroscopy (SORS), was recently devised for non-invasively probing the contents of diffusely scattering and opaque containers. Here, we demonstrate a modified portable SORS sensor for detecting concealed substances in-field under different background lighting conditions. Samples including explosive precursors, drugs and an organophosphate insecticide (chemical warfare agent surrogate) were concealed inside diffusely scattering packaging including plastic, paper and cloth. Measurements were carried out under incandescent and fluorescent light as well as under daylight to assess the suitability of the probe for different real-life conditions. In each case, it was possible to identify the substances against their reference Raman spectra in less than one minute. The developed sensor has potential for rapid detection of concealed hazardous substances in airports, mail distribution centers and customs checkpoints.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

On 1 January 2010, the Assisted Reproductive Treatment Act 2008 (Vic) came into force. The legislation was the outcome of a detailed review and consultation process undertaken by the Victorian Law Reform Commission. Arguably, the change to the regulatory framework represents a significant shift in policy compared to previous regulatory approaches on this topic in Victoria. This article considers the impact of the new legislation on eligibility for reproductive treatments, focusing on the accessibility of such services for the purpose of creating a “saviour sibling”. It also highlights the impact of the Victorian regulatory body’s decision to abolish its regulatory policies on preimplantation genetic diagnosis and preimplantation tissue-typing, concluding that the regulatory approach in relation to these latter issues is similar to other Australian jurisdictions where such practices are not addressed by a statutory framework.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effects of tumour motion during radiation therapy delivery have been widely investigated. Motion effects have become increasingly important with the introduction of dynamic radiotherapy delivery modalities such as enhanced dynamic wedges (EDWs) and intensity modulated radiation therapy (IMRT) where a dynamically collimated radiation beam is delivered to the moving target, resulting in dose blurring and interplay effects which are a consequence of the combined tumor and beam motion. Prior to this work, reported studies on the EDW based interplay effects have been restricted to the use of experimental methods for assessing single-field non-fractionated treatments. In this work, the interplay effects have been investigated for EDW treatments. Single and multiple field treatments have been studied using experimental and Monte Carlo (MC) methods. Initially this work experimentally studies interplay effects for single-field non-fractionated EDW treatments, using radiation dosimetry systems placed on a sinusoidaly moving platform. A number of wedge angles (60º, 45º and 15º), field sizes (20 × 20, 10 × 10 and 5 × 5 cm2), amplitudes (10-40 mm in step of 10 mm) and periods (2 s, 3 s, 4.5 s and 6 s) of tumor motion are analysed (using gamma analysis) for parallel and perpendicular motions (where the tumor and jaw motions are either parallel or perpendicular to each other). For parallel motion it was found that both the amplitude and period of tumor motion affect the interplay, this becomes more prominent where the collimator tumor speeds become identical. For perpendicular motion the amplitude of tumor motion is the dominant factor where as varying the period of tumor motion has no observable effect on the dose distribution. The wedge angle results suggest that the use of a large wedge angle generates greater dose variation for both parallel and perpendicular motions. The use of small field size with a large tumor motion results in the loss of wedged dose distribution for both parallel and perpendicular motion. From these single field measurements a motion amplitude and period have been identified which show the poorest agreement between the target motion and dynamic delivery and these are used as the „worst case motion parameters.. The experimental work is then extended to multiple-field fractionated treatments. Here a number of pre-existing, multiple–field, wedged lung plans are delivered to the radiation dosimetry systems, employing the worst case motion parameters. Moreover a four field EDW lung plan (using a 4D CT data set) is delivered to the IMRT quality control phantom with dummy tumor insert over four fractions using the worst case parameters i.e. 40 mm amplitude and 6 s period values. The analysis of the film doses using gamma analysis at 3%-3mm indicate the non averaging of the interplay effects for this particular study with a gamma pass rate of 49%. To enable Monte Carlo modelling of the problem, the DYNJAWS component module (CM) of the BEAMnrc user code is validated and automated. DYNJAWS has been recently introduced to model the dynamic wedges. DYNJAWS is therefore commissioned for 6 MV and 10 MV photon energies. It is shown that this CM can accurately model the EDWs for a number of wedge angles and field sizes. The dynamic and step and shoot modes of the CM are compared for their accuracy in modelling the EDW. It is shown that dynamic mode is more accurate. An automation of the DYNJAWS specific input file has been carried out. This file specifies the probability of selection of a subfield and the respective jaw coordinates. This automation simplifies the generation of the BEAMnrc input files for DYNJAWS. The DYNJAWS commissioned model is then used to study multiple field EDW treatments using MC methods. The 4D CT data of an IMRT phantom with the dummy tumor is used to produce a set of Monte Carlo simulation phantoms, onto which the delivery of single field and multiple field EDW treatments is simulated. A number of static and motion multiple field EDW plans have been simulated. The comparison of dose volume histograms (DVHs) and gamma volume histograms (GVHs) for four field EDW treatments (where the collimator and patient motion is in the same direction) using small (15º) and large wedge angles (60º) indicates a greater mismatch between the static and motion cases for the large wedge angle. Finally, to use gel dosimetry as a validation tool, a new technique called the „zero-scan method. is developed for reading the gel dosimeters with x-ray computed tomography (CT). It has been shown that multiple scans of a gel dosimeter (in this case 360 scans) can be used to reconstruct a zero scan image. This zero scan image has a similar precision to an image obtained by averaging the CT images, without the additional dose delivered by the CT scans. In this investigation the interplay effects have been studied for single and multiple field fractionated EDW treatments using experimental and Monte Carlo methods. For using the Monte Carlo methods the DYNJAWS component module of the BEAMnrc code has been validated and automated and further used to study the interplay for multiple field EDW treatments. Zero-scan method, a new gel dosimetry readout technique has been developed for reading the gel images using x-ray CT without losing the precision and accuracy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Six Sigma technique is one of the quality management strategies and is utilised for improving the quality and productivity in the manufacturing process. It is inspired by the two major project methodologies of Deming’s "Plan – Do – Check – Act (PDCA)" Cycle which consists of DMAIC and DMADV. Those two methodologies are comprised of five phases. The DMAIC project methodology will be comprehensively used in this research. In brief, DMAIC is utilised for improving the existing manufacturing process and it involves the phases Define, Measure, Analyse, Improve, and Control. Mask industry has become a significant industry in today’s society since the outbreak of some serious diseases such as the Severe Acute Respiratory Syndrome (SARS), bird flu, influenza, swine flu and hay fever. Protecting the respiratory system, then, has become the fundamental requirement for preventing respiratory deceases. Mask is the most appropriate and protective product inasmuch as it is effective in protecting the respiratory tract and resisting the virus infection through air. In order to satisfy various customers’ requirements, thousands of mask products are designed in the market. Moreover, masks are also widely used in industries including medical industries, semi-conductor industries, food industries, traditional manufacturing, and metal industries. Notwithstanding the quality of masks have become the prioritisations since they are used to prevent dangerous diseases and safeguard people, the quality improvement technique are of very high significance in mask industry. The purpose of this research project is firstly to investigate the current quality control practices in a mask industry, then, to explore the feasibility of using Six Sigma technique in that industry, and finally, to implement the Six Sigma technique in the case company to develop and evaluate the product quality process. This research mainly investigates the quality problems of musk industry and effectiveness of six sigma technique in musk industry with the United Excel Enterprise Corporation (UEE) Company as a case company. The DMAIC project methodology in the Six Sigma technique is adopted and developed in this research. This research makes significant contribution to knowledge. The main results contribute to the discovering the root causes of quality problems in a mask industry. Secondly, the company was able to increase not only acceptance rate but quality level by utilising the Six Sigma technique. Hence, utilising the Six Sigma technique could increase the production capacity of the company. Third, the Six Sigma technique is necessary to be extensively modified to improve the quality control in the mask industry. The impact of the Six Sigma technique on the overall performance in the business organisation should be further explored in future research.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

his paper formulates an edge-based smoothed conforming point interpolation method (ES-CPIM) for solid mechanics using the triangular background cells. In the ES-CPIM, a technique for obtaining conforming PIM shape functions (CPIM) is used to create a continuous and piecewise quadratic displacement field over the whole problem domain. The smoothed strain field is then obtained through smoothing operation over each smoothing domain associated with edges of the triangular background cells. The generalized smoothed Galerkin weak form is then used to create the discretized system equations. Numerical studies have demonstrated that the ES-CPIM possesses the following good properties: (1) ES-CPIM creates conforming quadratic PIM shape functions, and can always pass the standard patch test; (2) ES-CPIM produces a quadratic displacement field without introducing any additional degrees of freedom; (3) The results of ES-CPIM are generally of very high accuracy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of the study: The purpose of this study is to investigate the influence of cultural diversity, in a multicultural nursing workforce, on the quality and safety of patient care and the work environment at King Abdul-Aziz Medical City, Riyadh region. Study background: Due to global migration and workforce mobility, to varying degrees, cultural diversity exists in most health services around the world, particularly occurring where the health care workforce is multicultural or where the domestic population comprises minority groups from different cultures speaking different languages. Further complexities occur when countries have a multicultural workforce which is different from the population for whom they care, in addition to the workers being from culturally diverse countries and with different languages. In Saudi Arabia the health system is mainly staffed by expatriate nurses who comprise 67.7% of the total number of nurses. Study design: This research utilised a case study design which incorporated multiple methods including survey, qualitative interviews and document review. Methods: The participant nurses were selected for the survey via a population sampling strategy; 319 nurses returned their completed Safety Climate Survey questionnaires. Descriptive and inferential statistics (Kruskal–Wallis test) were used to analyse survey data. For the qualitative component of the study, a purposive sampling strategy was used; 24 nurses were interviewed using a semi-structured interview technique. The documentary review included KAMC-R policy documents that met the inclusion criteria using a predetermined data abstraction instrument. Content analysis was used to analyse the policy documents data. Results: The data revealed the nurses‘ perceptions of the clinical climate in this multicultural environment is that it was unsafe, with a mean score of 3.9 out of 5. No significant difference was detected between the age groups or years of experience of the nurses and the perception of safety climate in this context; the study did reveal a statistically significant difference between the cultural background categories and the perception of safety climate. The qualitative phase indicated that the nurses within this environment were struggling to achieve cultural competence; consequently, they were having difficulties in meeting the patients‘ cultural and spiritual needs as well as maintaining a high standard of care. The results also indicated that nurses were disempowered in this context. Importantly, there was inadequate support by the organisation to manage the cultural diversity issue and to protect patients from any associated risks, as demonstrated by the policy documents and supported by the nurses‘ experiences. The study also illustrated the limitations of the conceptual framework of cultural competence when tested in this multicultural workforce context. Therefore, this study generated amendments to the model that is suitable to be used in the context of a multicultural nursing workforce. Conclusion: The multicultural nature of this nursing work environment is inherently risky due to the conflicts that arise from the different cultural norms, beliefs, behaviours and languages. Further, there was uncertainty within the multicultural nursing workforce about the clinical and cultural safety of the patient care environment and about the cultural safety of the nursing workforce. The findings of the study contribute important new knowledge to the area of patient and nurse safety in a multicultural environment and contribute theoretical development to the field of cultural competence. Specifically, the findings will inform policy and practice related to patient care in the context of cultural diversity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This book examines diverse aspects of the social experiences and cultural practices of Lebanese migrants and their descendants in Australia. It is available at the Institute for Migration Studies for the prices listed below. To obtain any additional information about the book please contact the Institute.