Wet Etching and Surface Analysis of Chemically Treated InGaN Films

This paper discusses the performance of different wet chemical etchants on InGaN. It is shown that certain etchants can be used to chemically etch and remove appreciable amounts of InGaN even though the etch rate is not as high as observed for other III-V materials. The performance of etchants studied here were (i) two different ratios of HF, HNO3, (ii) cyclic usage of NH4OH followed by HCl, (iii) hot H2SO4 and H3PO4 mixture, and (iv) conc. NH4OH. The etched surfaces have then been analyzed by x-ray photoelectron spectroscopy (XPS). Different etch residues were observed on the top surface. These results suggest an alternative to reactive plasma etching or photo-enhanced electrochemical etching of InGaN type materials. Based on the observed performance of the etchants studied, it was also possible to segregate the surface cleaning protocols and etchants

African Water: Supporting African involvement in the EU Framework Programme.

Water researchers in developing countries have yet to take full advantage of the funding and collaborative research opportunities presented by the EU Framework Programme. There are a variety of reasons for this, such as insufficient information and a lack of previous experience. The African Water initiative aims to increase the involvement of African water researchers through a range of activities including communication and dissemination, capacity building and development, and complementary initiatives. The project has demonstrated that there is a demand for such sector-specific support activities. However, African Water is a small component of a much larger process of partnership between the developed and the less-developed countries of the world, involving many different European and African organisations working across political, institutional and technical domains, and complementing the wide range of actions already being undertaken

A Methodology to Inter-Compare Brass and Such Alloys Manufactured at Different Geographical Locations

319-329This paper is about a method developed to normalize the Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) data counts of each constituent ion in a mass spectra, by dividing each ion count with the total ion count. So by comparing their statistical means, data of different samples of any alloy like brass etc. from different places around the world can be inter-compared using TOF-SIMS data collected using similar separate instruments under similar experimental conditions. Such a methodology can also be extended to analysis of constituents of other materials using TOF-SIMS as well. Here, all brass samples were chosen on a representative global basis and had similar end uses. Variations in normalized mean counts of major constituent ions suggest that brass produced in different parts of the world for similar uses can be a little different in composition and can be readily identified and distinguished using their normalized statistical mean ion counts using TOF-SIMS. Their performance does not drastically change due to variation in such constituents of the alloy as the thermal treatments used on them were possibly different. Based on these observations, it was felt that unless there is a drastic change in any alloys’ micro-structure or crystalline phase properties, there will be no drastic change in its properties with variation of its’ major or minor alloying constituents. Data from literature using different aluminum alloys as a representative example and using their available data on micro-hardness and noting their variation with alloying also suggests such a phenomena

A Methodology to Inter-Compare Brass and Such Alloys Manufactured at Different Geographical Locations

This paper is about a method developed to normalize the Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) data counts of each constituent ion in a mass spectra, by dividing each ion count with the total ion count. So by comparing their statistical means, data of different samples of any alloy like brass etc. from different places around the world can be inter-compared using TOF-SIMS data collected using similar separate instruments under similar experimental conditions. Such a methodology can also be extended to analysis of constituents of other materials using TOF-SIMS as well. Here, all brass samples were chosen on a representative global basis and had similar end uses. Variations in normalized mean counts of major constituent ions suggest that brass produced in different parts of the world for similar uses can be a little different in composition and can be readily identified and distinguished using their normalized statistical mean ion counts using TOF-SIMS. Their performance does not drastically change due to variation in such constituents of the alloy as the thermal treatments used on them were possibly different. Based on these observations, it was felt that unless there is a drastic change in any alloys’ micro-structure or crystalline phase properties, there will be no drastic change in its properties with variation of its’ major or minor alloying constituents. Data from literature using different aluminum alloys as a representative example and using their available data on micro-hardness and noting their variation with alloying also suggests such a phenomen

Comparison of Cheap Imported Stainless Steel Samples with Indian-made Samples and a Crystalline Phase Based Methodology for Bench-marking them

455-463In the emerging South Asian markets, from the commercial as well as engineering point of view, performance and quality of any local engineering product like steel structures vis a vis similar but imported, cheap materials is always an issue. In this paper, as a representative case, we discuss the composition, crystalline phase and microstructure of two most common stainless steel grades manufactured locally by the major government of India sponsored (GOIS) Steel maker and compare them with similar cheap imported items that some local private businesses prefer due to slightly lower costs but having similar materials usage parameters. We have also used wet etch based micrographic analysis to compare surface morphology and have also done composition analysis in our results. It is shown that even if ASTM standards of composition are followed, since their crystalline phase components are not the same, their performance and properties are never comparable. More stringent quality bench-marking of such alloy materials for checking repeatibility of batches and processes using X-ray diffraction and Raman spectral data analysis is thereby proposed

Rare germline variants in DNA repair genes and the angiogenesis pathway predispose prostate cancer patients to develop metastatic disease

Background Prostate cancer (PrCa) demonstrates a heterogeneous clinical presentation ranging from largely indolent to lethal. We sought to identify a signature of rare inherited variants that distinguishes between these two extreme phenotypes. Methods We sequenced germline whole exomes from 139 aggressive (metastatic, age of diagnosis < 60) and 141 non-aggressive (low clinical grade, age of diagnosis ≥60) PrCa cases. We conducted rare variant association analyses at gene and gene set levels using SKAT and Bayesian risk index techniques. GO term enrichment analysis was performed for genes with the highest differential burden of rare disruptive variants. Results Protein truncating variants (PTVs) in specific DNA repair genes were significantly overrepresented among patients with the aggressive phenotype, with BRCA2, ATM and NBN the most frequently mutated genes. Differential burden of rare variants was identified between metastatic and non-aggressive cases for several genes implicated in angiogenesis, conferring both deleterious and protective effects. Conclusions Inherited PTVs in several DNA repair genes distinguish aggressive from non-aggressive PrCa cases. Furthermore, inherited variants in genes with roles in angiogenesis may be potential predictors for risk of metastases. If validated in a larger dataset, these findings have potential for future clinical application

Infrastructure for Detector Research and Development towards the International Linear Collider

The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture

Diagnosis of chronic conditions with modifiable lifestyle risk factors in selected urban and rural areas of Bangladesh and sociodemographic variability therein

<p>Abstract</p> <p>Background</p> <p>Bangladesh suffers from a lack of healthcare providers. The growing chronic disease epidemic's demand for healthcare resources will further strain Bangladesh's limited healthcare workforce. Little is known about how Bangladeshis with chronic disease seek care. This study describes chronic disease patients' care seeking behavior by analyzing which providers diagnose these diseases.</p> <p>Methods</p> <p>During 2 month periods in 2009, a cross-sectional survey collected descriptive data on chronic disease diagnoses among 3 surveillance populations within the International Center for Diarrheal Disease Research, Bangladesh (ICDDR, B) network. The maximum number of respondents (over age 25) who reported having ever been diagnosed with a chronic disease determined the sample size. Using SAS software (version 8.0) multivariate regression analyses were preformed on related sociodemographic factors.</p> <p>Results</p> <p>Of the 32,665 survey respondents, 8,591 self reported having a chronic disease. Chronically ill respondents were 63.4% rural residents. Hypertension was the most prevalent disease in rural (12.4%) and urban (16.1%) areas. In rural areas chronic disease diagnoses were made by MBBS doctors (59.7%) and Informal Allopathic Providers (IAPs) (34.9%). In urban areas chronic disease diagnoses were made by MBBS doctors (88.0%) and IAP (7.9%). Our analysis identified several groups that depended heavily on IAP for coverage, particularly rural, poor and women.</p> <p>Conclusion</p> <p>IAPs play important roles in chronic disease care, particularly in rural areas. Input and cooperation from IAPs are needed to minimize rural health disparities. More research on IAP knowledge and practices regarding chronic disease is needed to properly utilize this potential healthcare resource.</p