12508 research outputs found
Sort by
An approximation to the PTT viscoelastic model for Gas Assisted Injection Moulding simulation
Get PDFYesAn approximation to the Phan-Thien Tanner (PTT) constitutive model is
developed with the aim of giving low-cost simulation of Gas Assisted Injection Moulding
(GAIM) while incorporating important viscoelastic characteristics. It is shown that the
developed model gives a response typical of full viscoelastic models in transient and steady state
uniaxial and constant shear rate deformations. The model is incorporated into a 3D
finite element GAIM simulation which uses the ‘pseudo-concentration' method to predict
residual polymer, and applied to published experimental results for a Boger fluid and a
shear-thinning polystyrene melt.
It is shown that the simulation gives a very good match to published results for the Boger
fluid which show increasing Residual Wall Thickness (RWT) with increasing Deborah
number. Against the shear-thinning polymer, the quality of match depends upon which of two
‘plausible' relaxation times is chosen; qualitatively different results arise from two different
means of estimating a single relaxation time. A ‘multi-mode' approach is developed to avoid
this uncertainty. It is shown that the multi-mode approach gives decreasing RWT with
increasing Deborah number in agreement with the published experimental results, and
avoids the issues that arise from estimating a single relaxation time for a molten polymer
Scope and limitations of the mathematical models developed for the forward feed multi-effect distillation process-a review
Get PDFYesDesalination has become one of the obvious solutions for the global water crisis due to affording high-quality water from seawater and brackish water resources. As a result, there are continuing efforts being made to improve desalination technologies, especially the one producing high-quantity freshwater, i.e., thermal desalination. This improvement must be accomplished via enhancement of process design through optimization which is implicitly dependent on providing a generic process model. Due to the scarcity of a comprehensive review paper for modeling multi-effect distillation (MED) process, this topic is becoming more important. Therefore, this paper intends to capture the evolution of modeling the forward feed MED (most common type) and shed a light on its branches of steady-state and dynamic modeling. The maturity of the models developed for MED will be thoroughly reviewed to clarify the general efforts made highlighting the advantages and disadvantages. Depending on the outputs of this review, the requirements of process development and emerging challengeable matters of modeling will be specified. This, in turn, would afford a possible improvement strategy to gain a reliable and sustainable thermal desalination process
Development of a Non-Invasive Proteomic Approach to Profiling Molecular Changes in the Microenvironment to Investigate Stages of Breast Health
Get PDFEarly detection of breast cancer is critical for increasing survival rates. However, currently available screening strategies provide ambiguous results, leaving invasive tissue biopsy procedures necessary for definitive diagnosis. Considerable efforts have investigated using nipple aspirate fluid (NAF), a liquid biopsy rich in proteins representative of the breast microenvironment, as a non-invasive source of early detection biomarkers. However, by using traditional two-dimensional discovery proteomic approaches, many technical challenges of using NAF have limited analysis of large sample sizing: such as low expressed volume (<10µL) or insufficient analytical material (<200µg protein).
Following non-invasive collection by manual massage, we developed a one-dimensional sample preparation workflow that reduced sample handling steps, minimised sample losses and increased sample throughput to 96-samples by using a PVDF-membrane based system, which was ideally suited to the NAF proteome. Samples were prepared within a single working day, and results correlated significantly with conventional in-solution protocols.
Proteins typically associated with the dysregulation of innate immune response and haemostatic pathways had a significantly altered proteome profile in response to breast cancer. Overall, our new workflow will allow future studies to take a more high-throughput approach, revealing biomarkers for breast cancer early detection, and providing a real impact
Reducing Teenage Pregnancy in England, 2010 to 2015: A case study
Get PDFThe policy to reduce teenage pregnancy in England has been used as a case
study to explore health policy sustainability. Between 2010 and 2015 many areas
across England sustained and improved their conception rate reductions
following implementation of the 2000-2010 national Teenage Pregnancy
Strategy. Little is known of the factors underpinning these successes in the policy
context beyond 2010. This thesis investigates sustained and improved reductions
in teenage pregnancy in local authority areas post 2010. The broader political
and economic context in which policy is shaped is examined, and the influence
of New Public Managerialism considered. The findings suggest three overarching
themes which impact on policy sustainability: leadership; understanding the
issue; and resources. The thesis develops a seven elements framework,
identifying factors to be analysed for policy sustainability. The thesis makes a unique contribution to the understanding of teenage pregnancy policy, providing
a detailed review of local actions post 2010. It further adds to the body of
knowledge regarding policy sustainability with the development of the seven
elements framework. In addition, the thesis is presented at a notable point in
history, as the global Covid-19 pandemic takes hold across the world. This
situation is considered in the light of insights from the thesis and implications for
the policy context into the future are contemplated
Corporate Tax Planning: Measurement, Incentives and Governance Effects
Get PDFThis research reviews the existing Tax Planning (TP) measures and explores the
consistency of UK firms’ engagement in TP; evaluates incentives for TP and its value
relevance in a signalling theory framework; and studies corporate governance effects
on TP for the firms in an institutional theory framework. It analyses a unique set of
1,482 hand-collected firm-year observations and proposes ‘undisclosed TP’ as a new
TP measure. It finds that firms consistently engage in TP and their TP disclosures
have improved; internationally oriented firms do not engage in TP to save taxes; risky
firms, firms with low operating cashflows and growing firms, however, do not engage
in TP to arrange funds internally – so they signal their non-engagement in TP to the
market. Further findings confirm public awareness and market valuation of firms’ TP
engagements. Boards’ tax affiliations result in reductions in tax payments (expenses)
for strongly (weakly) governed firms. Professional accountancy qualifications on the
board result in significantly higher tax payments for weakly governed firms. The
auditors’ provided tax services (institutional ownership) result in higher tax payments
for weakly (strongly) governed firms suggesting supplementary (complementary) role
of auditors (institutional ownership) for the internal governance on TP. This research
concludes that there is a need for further TP disclosures to reduce the information
asymmetry associated with negatively valued TP activities; recommends auditors’
involvement in TP services; and recommends tax affiliates on the board to bring tax savings
in a strongly governed environment. The current study’s findings have important theoretical and practical implications.University of Bradfor
An Investigation into the Role of Local Government in Enhancing the Public Participation in Sindh, Pakistan: Policy and Practice in Service Delivery
Get PDFIt is generally recognised that the primary role of the decentralise local
governance is to establish closer relationship between rural communities and the
governing authorities in local development. In Pakistan, the system of local
governments has always been introduced by the non-democratic forces. The
decentralised governments have often been discontinued by the civilian
governments of Pakistan.
This study has sought to examine the role of the decentralised local governance
in initiating the local community participation in local development in the province
of Sindh, Pakistan. This thesis responds the questions about the initiatives taken
by the local government authorities and the genuine local community participation
in local community development programs. It further explores the main barriers
to local public participation in the local policy making and implementation in
Sindh.
The findings suggest that the challenges to participation have been ever
increasing. The military establishment’s hold on the central state policies has
weakened the public empowering national laws. Furthermore, the local
government’s role to initiate meaningful local community involvement in
development projects of the decentralised local governance has been engrossed
by the hold of feudal lords, corruption, favouritism, and the attitude of indifference
on the part of provincial and national governments. Thus, it is argued that, in such
dominant military state and feudal lords’ system, there is no positive link between
the local government reforms and the democratic participation in the local
decision-making. Based on these findings, a realistic model for participation is
introduced and relevant implications are considered
Distribution Network Reconfiguration Considering Security-Constraint and Multi-DG Configurations
No full textYesThis paper proposes a novel method for distribution network reconfiguration considering security-constraints and multi-configuration of renewable distributed generators (DG). The objective of the proposed method is to minimize the total operational cost using security constrained optimal power flow (SCOPF). The impact of multi-configuration of renewable DGs in a meshed network is investigated. In this work, lines were added to the radial distribution network to analyse the network power flow in different network configurations. The added lines were connected to the closest generator bus which offered least operating cost. A 16-bus UK generic distribution system (UKGDS) was used to model the efficiency of the proposed method. The obtained results in multi-DG configuration ensure the security of the network in N-1 contingency criteria
Adipose tissue: a source of stem cells with potential for regenerative therapies for wound healing
No full textYesInterest in adipose tissue is fast becoming a focus of research after many years of being considered as a simple connective tissue. It is becoming increasingly apparent that adipose tissue contains a number of diverse cell types, including adipose-derived stem cells (ASCs) with the potential to differentiate into a number of cell lineages, and thus has significant potential for developing therapies for regenerative medicine. Currently, there is no gold standard treatment for scars and impaired wound healing continues to be a challenge faced by clinicians worldwide. This review describes the current understanding of the origin, different types, anatomical location, and genetics of adipose tissue before discussing the properties of ASCs and their promising applications for tissue engineering, scarring, and wound healing.The authors thank the Plastic Surgery and Burns Research Unit at the University of Bradford, Bradford, UK for financial support for LV
Differences and Similarities between Coronavirus and other Viruses
No full textYesCoronavirus is the most dangerous virus in the world wide and it can easy spread between people, animals and plants because it is existing on one strand of RNA (Ribonucleic Acid) and it can duplicate faster than any virus. The source of coronavirus is still unknown, but some sources said that it came from seafood market and other sources said that it came from bat and snakes. It starts in Wuhan; China and every day the fatality increases. The symptoms are like a SARS-CoV (acute respiratory syndrome coronavirus)) and MERS-CoV (Middle East Respiratory Syndrome Coronavirus). By using nucleotide sequence of coronavirus from NCBI (National Center for Biotechnology Information) and some programs that ran on Matlab, the results show that there are some differences and similarities between coronavirus and other viruses such as Ebola, Flu-b, Hepatitis B, HIV and Zika especially for DEBs (distinct excluded blocks) program that shows at 5bp (base pair) there is a common with slightly difference between coronavirus “cgggg” and Ebola virus “cgtgg”. The aim from this study is to find a way to help doctors and scientists to stop spreading the coronavirus or to destroy it
The Automated Solar Activity Prediction System (ASAP) Update Based on Optimization of a Machine Learning Approach
No full textNoQuite recently, considerable attention has been paid to solar flare prediction because extreme solar eruptions could affect our daily life activities and on different technologies. Therefore, this paper presents a novel method of the development of improved second-generation of the Automated Solar Activity Prediction system (ASAP). The suggested algorithm improves the ASAP system by expanding a period of training vector and generating new machine learning rules to be more successful. Two neural networks are responsible for determining whether the sunspots group will release flare as well as determining if the flare is an M-class or X-class. Several measurement criteria are applied to determine the extent of system performance also all results are provided in this paper. Furthermore, the quadratic score (QR) is used as a metric criterion to compare between the prediction of the proposed algorithm with the Space Weather Prediction Center (SWPC) between 2012 and 2013. The results exhibit that the proposed algorithm outperforms the old ASAP system. Keywords: Solar flares, Machine Learning, Neural network, Space, Prediction, weather