Study of the crystallization behavior of polyethylene oxide in compatibilized and uncompatibilized polypropylene/polyethylene oxide blends

Compatibilization of incompatible isotactic polypropylene (iPP)/polyethylene oxide (PEO) is studied with an emphasis on the crystallization behavior of polyethylene oxide. An attempt is made to correlate the crystallization data for PEO obtained from optical microscopy, differential scanning calorimetry, x-ray diffraction, infrared spectroscopy and dynamic mechanical analysis. PEO and iPP are incompatible in the temperature range -50C to 200C. iPP was used as the matrix while PEO was used as the dispersed phase. Experimental observations demonstrated that PEO underwent fractionated crystallization in the blends in the temperature region from -10C to 40C when cooled at a rate of 10C/min. PEO domains nucleated homogeneously as well as heterogeneously in these blends. Larger domains (30-100 microns) crystallized at higher temperatures (heterogeneous nucleation), while smaller domains (10-60 microns) crystallized at lower temperatures (homogeneous nucleation). Heterogeneous nucleation occurred both thermally, and athermally. The graft copolymer, polypropylene-graft-maleic anhydride-graft-polyethylene glycol was used to increase compatibility between iPP and PEO. Three blends systems were studied; iPP and PEO, polypropylene-graft-maleic anhydride and PEO and polypropylene-graft-maleic anhydride-graft-polyethylene oxide and PEO. An increase in the concentration of PEO in the blends increased its crystallinity. However there was a decrease in the crystallinity of PEO, as the blends were made more compatible. This behavior of PEO was observed both by optical microscopy differential scanning calorimetry. Results from x-ray diffraction, however, showed an increase in the crystallinity of PEO relative to iPP as compatibility between the blends increased. The compatibilizer reduced the size of the dispersed phase thus increasing compatibility between iPP and PEO. There was clustering of small PEO domains in the compatibilized blends. Heterogeneous nucleation can be seen only for the 30% PEO concentration of the uncompatibilized blends. The melting point of PEO in the blends was depressed, while that of iPP was the same as the pure polymer. PEO domains existed as spherical droplets in the melt. The crystallization temperatures for PEO were higher when seen through optical microscopy as compared to differential scanning calorimetry. Results from infrared spectroscopy revealed a change in the nature of the spectra for iPP and PEO in the blends as compared to the pure spectra. The infrared spectra of the blends are distinctly different from the coadded spectra of iPP and PEO. Spectroscopy also revealed a change in the composition or structure of PEO in the blends from the targeted compositions. Mechanical analysis revealed a change in the nature of the graph of the loss modulus versus temperature, as the blends are made compatible. Crystal rearrangement of both iPP and PEO is seen as the blends were heated in the temperature range from -50C to 100C

Lymphedema In Ovarian Cancer Survivors: Assessing Diagnostic Methods And Risk Factors

Purpose: Lymphedema is a poorly understood but significant side effect of treatment for gynecologic cancer. We sought to determine the prevalence of lower limb lymphedema (LLL) in a sample of ovarian cancer survivors via three different diagnostic methods while also evaluating the agreement between each method and assessing potential risk factors for LLL. Methods: LLL was measured via self-report questionnaire, optoelectric perometry, and evaluation by a certified lymphedema specialist in women (n = 48) who had completed treatment for their ovarian cancer and were physically inactive. Results: LLL prevalence ranged from 19-42% depending on the diagnostic method, with the self-report questionnaire and the lymphedema specialist evaluation having the highest agreement (k = 0.646). No risk factors were significantly associated with LLL, although there was a trend towards higher total body fat and BMI among those with LLL versus lower body fat and BMI among those without LLL. Conclusion: There is a strong need for further research, given that the prevalence of LLL could be as high as 42 percent among women treated for ovarian cancer

The Road to Retirement: Bumpy or Smooth, Depends on Your Route

Defined Contribution (DC) plans are rapidly becoming the primary retirement investment vehicle for a majority of employees across the US and other markets around the globe. Asset allocation for DC plans has to strike a balance between growth and protection assets over the savings lifecycle while protecting the long-term purchasing power of the nest egg. Due to the long duration of retirement investing and various risks associated with it, implementing the right asset allocation has become critical and challenging for DC plans. The unique Risk Focused methodology presented in this paper aims to address the shortcomings of conventional Target Date Funds experienced during the 2008 financial crisis. The proposed approach addresses the cumulative impact of shortfall, sequence of returns, longevity, and market risks in determining asset allocation at different time horizons. This is accomplished by combining the term structure of risk, return, and covariance of asset classes with an explicit risk budget. The Risk Focused glide path potentially delivers comparable retirement wealth outcomes with enhanced downside protection, lower journey volatility, and attempts to facilitate a smoother journey on the road to retirement. Hence, the caption of the paper, Road to Retirement – Bumpy or Smooth, Depends on your Route

Is M&A Self-Dealing in the Context of Peer Benchmarking of CEO Pay?

We define two effects: (a) percentage difference between median CEO pay of compensation peers and their counterfactual peers (Peer pay effect, PPE), and (b) percentage difference between focal firm CEO pay and the median CEO pay of their compensation peers (CEO pay effect, CPE). We find a negative relation between M&A announcement period abnormal returns and pre-announcement PPE. The PPE (CPE) is lower (higher) in acquiring years relative to non-acquiring years. We show that the lower PPE is consistent with better governance and higher CPE is due to benchmarking against peers with higher median CEO pay and for completing acquisitions

Priority Based Approach for Operation of Rural Energy Centers

Electrical Engineering Technolog

A foundation for integrating heterogeneous data sources

We study the foundations of the integration issues that arise in a federation of heterogeneous data sources, possibly storing related information. Some of the notable features of our approach, motivated by the shortcomings of existing technology, include (a) the ability to share data across multiple heterogeneous data sources, (b) the ability to manipulate the meta-data (schema) component of a data source in the same vein as data can be manipulated, and (c) the ability to query besides well-structured data sources (such as relational databases), semi-structured data sources (such as the HTML documents on the World Wide Web). Our approach is declarative and is based on a simple logic called SchemaLog. SchemaLog's syntax is higher-order but it enjoys a first-order semantics. We present a formal account of the semantics of SchemaLog by developing a model theory, a proof theory, and a fixpoint theory. SchemaLog can be implemented on top of existing database systems in a 'non-intrusive' way. Realizing an efficient implementation of a SchemaLog-based system warrants the study of the calculus and algebraic languages underlying SchemaLog. We develop a new algebra by extending the conventional relational algebra with some new operations that are capable of manipulating both data and schema information in a federation of databases. We also develop a calculus language inspired by SchemaLog. Based on the calculus language, we study varying notions of safety that naturally arise in a federation scenario. One of our primary concerns in this dissertation has been the practical relevance and industrial impact of our contributions. In this vein and inspired by the SchemaLog experience, we develop a principled extension of SQL, called SchemaSQL. SchemaSQL is downward compatible with SQL syntax and semantics and is capable of (a) representing data in a database, in a structure substantially different from the original database, in which data and meta-data may be interchanged, (b) creating views whose schema is dynamically dependent on the input database, (c) expressing novel aggregation (over rows, and in general blocks of information) operations, in the spirit of some of the functionalities needed in OLAP applications, and (d) providing a great facility for interoperability and data, meta-data management in multidatabase systems. Legacy as well as non-traditional information systems constitute an important fragment of the data sources available in real-life. We demonstrate that SchemaLog can be naturally extended to support non-relational systems as well. In particular, we address the fundamental problem of retrieving specific information of interest to the user, from the enormous number of resources that are available on the Web. With this in mind, and inspired by SchemaLog, we develop a simple logic called WebLog and illustrate the simplicity and power of WebLog for Web querying and restructuring using a variety of applications involving real-life information in the Web. (Abstract shortened by UMI.

The effectiveness of the Right to Education (RTE) Act in unrecognised schools of Delhi, India

PhD ThesisIn 2009, the Government of India introduced a new Education Act known as the “Right to Education” (RTE). The Act was brought out with all good intentions that would focus on the provision of education to 6 –14 years of age. Focused heavily, on input based indicators the Act intended to improve learning outcomes of children enrolled in private and public schools. The RTE act is being imposed stringently on several low-cost private schools across Delhi, and they have been, threatened with closure in the case of non-compliance to the RTE indicators. This thesis investigates the possible consequences of the Act. The current research using mixed methods attempts to understand the relationship between the various RTE input indicators and the academic outcomes of the children enrolled in the threatened private schools of Delhi. The study used two sets of instruments to measure the learning outcomes of students. First, a test for subject-specific competence was measured through a bespoke exam, known as the ‘diagnostic test’. Second, general intelligence was, measured through Raven’s standard progressive matrices test to control for innate ability. The background of children was also gathered using a questionnaire. Information on school RTE indicators were collected through a school questionnaire. Teacher data related to the RTE were gathered through a semi-structured teacher questionnaire. An in-depth interview was carried out to collect qualitative data and gained narrative accounts from school head teachers and principals to understand more deeply how the RTE indicators were impacting on student outcomes and low-cost private schools in Delhi. These data were analysed using linear regression models, to investigate the impact of the RTE on schools and student outcomes. The study revealed that most RTE infrastructure indicators were not statistically significant regarding student outcomes. Only, two factors were positively significant first, the provision of mid-day meals and second the presence of a library. Teacher qualifications have a positive influence on student outcomes, however other factors mentioned in the RTE including job status of the teacher, the salary range or parent-teacher association meetings, were found not to influence test scores. Finally, regarding the core indicators of the RTE, only two factors affected academic outcomes positively and were found to be significant. First, practising inclusivity and second, allowing ‘hands-on-learning’ for students. Schools that charged a fee on a higher spectrum, as compared to those which charged fees on a lower range, were found to affect student outcomes negatively, at a significant level. Other RTE academic and institutional indicators seemed to have negative or no impact on student learning outcomes, however, they were not significant. ii A major policy implication of this research is to provide feedback to the Government of IndiaA major policy implication of this research is to provide feedback to the Government of India on the gaps that currently exist in the RTE act, that affect student’s learning in low-cost private schools, threatened with closure notices. The study is unique as it gathered data from officially threatened schools, from the districts of New Delhi, that weakly comply with the RTE. The research provides insights generated from data and in-depth discussions with school owners on schooling inputs likely to affect student learning outcomes, teaching and the operation of low-cost private schools to inform future discussions around the RTE

Resilient Supply Chain in United Arab Emirates

Supply chain disruption refers to any event or occurrence that interrupts the flow of goods or services from suppliers to customers. This disruption can have a significant impact on businesses and can lead to delays, shortages, and increased costs. To mitigate the impact of supply chain disruptions, businesses can take several steps. These include diversifying their supplier base, maintaining safety stock levels, investing in technology to improve supply chain visibility, and developing contingency plans for dealing with disruptions. In addition, businesses can work with their suppliers and customers to build stronger relationships and improve communication and collaboration. This can help to identify potential issues early and allow for more effective problem-solving when disruptions do occur. Overall, supply chain disruption is a significant challenge for businesses, but with careful planning and proactive measures, it is possible to minimize the impact and maintain business continuity. The mixed methodology used in the research to capture the expertise opinions and the stakeholder’s expectations of the Supply chain and its necessity to be resilient