Single-Crystalline Graphene by Low-Pressure CVD Method: Nucleation Limited Growth, Transfer, and Characterization

Graphene has attracted enormous attention due to its unique characteristics. However, the LPCVD graphene grown on copper turns out to be polycrystalline because of the high nucleation density (ND) on the copper foil surface. In order to realize better quality LPCVD graphene, this ND needs to be significantly reduced. Based on the observations from our initial graphene growths on as-received copper, we figured that the uneven Cu surfaces with defects produce large NDs. At a large ND, the graphene flakes nucleated at different sites coalesced to produce polycrystalline graphene. Due to such issues, we have implemented an electropolishing technique to smoothen the native surface of the copper foil. We will discuss the successful implementation of the surface smoothening process to reduce nucleation site formation while limiting the surface defects (which leads to wrinkle formation). The annealing process was also helpful to flatten the surface during the growth process further. We have also observed that graphene grows across Cu grain boundaries and, in the process, produces an additional surface area for graphene growth. That later causes to form wrinkles, which affect graphene properties negatively. In the next project, the effect of multi-step copper surface oxidization, base pressure vacuum in the middle of the process, and integration of Cu enclosures on suppressing the ND will be discussed. The technique is based on the self-cleaning characteristics of copper oxides and the metal evaporation in a high vacuum at high temperatures. The ND has reduced to ~5 nucleation/cm2 on average (an improvement compared to the previously reported minimum value, ten nucleation/cm2 which was obtained using copper enclosures), and the graphene/copper surface has become smoother. The self-aligned graphene island geometry and shape of the flakes have reflected the symmetry and the single crystallinity of graphene. The final project will discuss the growth of cm-scale graphene flakes on Cu and 3D-multilayered graphene on 3D-Ni foams and used Ni\u27s gettering carbon diffusion effect to make the Cu foil carbon-free. The Ni-foam/Cu enclosure was oxidized in situ to assist with the self-cleaning process of metal oxides. The ND has been reduced to ~0.57 nucleation/cm2 and obtained cm-scale graphene flakes

Application of Water Quality Index to Monitor Ground Water Quality: A Case Study in Colombo Catchment of Sri Lanka

Deterioration of groundwater quality directly threatens the livability of a community. Sri Lanka is currently undergoing a rapid increase in the demand for water, particularly for urban/rural water supplies, irrigated agriculture and in the industrial sector, exerting a considerable pressure on the available groundwater resources. This study was carried out to assess the status of groundwater quality around the Parliament Lake, in Colombo catchment, Sri Lanka by employing the Canadian Council of Ministers of the Environment (CCME) Water Quality Index (WQI) from September 2016 to September 2017 (one year). The objective of the study was to assess the suitability of groundwater in the study area as potable water through CCME WQI. Water samples were collected from thirty-four (34) locations including twenty-six (26) domestic shallow wells and eight (08) deep wells. The in-situ measurements of the parameters pH, Temperature, Dissolved Oxygen, Total Dissolved Solids, Electrical Conductivity, Salinity were conducted monthly while the laboratory testing for Ammonia, Nitrate, Phosphate, Chemical Oxygen Demand, Biological Oxygen Demand were conducted twice for fifteen (15) selected wells during the project period. CCME WQI was calculated taking pH, Temperature, Dissolved Oxygen, Total Dissolved Solids, and Electrical Conductivity into account. Results revealed Nitrate, Sulphate and Calcium levels of both shallow and deep wells were within the Maximum Permissible Levels in the SLS 614, 1,983 drinking water standards. The Nitrate levels of both shallow and deep wells were comparatively high in the dry season and in contrast, Phosphate, Calcium, Sulphate and BOD values in most the shallow wells and deep wells were comparatively high in the wet season. High Ammonia levels of five (05) out of fifteen (15) selected shallow wells exceeded the maximum permissible level given in standards. The highest COD levels in dry and wet seasons were recorded 42.0 mg/l and 88.0 mg/l respectively indicating that the water is unsuitable for drinking. According to the CCME WQI, the quality of twenty three (23) out of twenty seven (27) shallow wells were in the “Marginal” level (85.19%) and one in “Poor” condition (3.70%). The water quality of these twenty four (24) shallow wells is frequently endangered or deteriorated. The CCME-WQI values indicated that the water in four Deep Wells is in good quality (57.14%), whereas water in two deep wells is in Marginal level quality. Present study revealed that GW 20, GW 08, GW 09, GW 10 and GW 28 have deteriorating water quality with downgrading parameters of Electrical Conductivity, Salinity, and Total Dissolved Solids. Accordingly, it is proposed to carry out a well-planned groundwater quality management mechanism to avoid further pollution. In addition, detail studies to identify the causes of ground water pollution should be conducted.Keywords: Ground water quality, Pollution, Colombo catchment, Water quality inde

Fighting Against XSS Attacks. A Usability Evaluation of OWASP ESAPI Output Encoding

Cross Site Scripting (XSS) is one of the most critical vulnerabilities exist in web applications. XSS can be prevented by encoding untrusted data that are loaded into browser content of web applications. Security Application Programming Interfaces (APIs) such as OWASP ESAPI provide output encoding functionalities for programmers to use to protect their applications from XSS attacks. However, XSS still being ranked as one of the most critical vulnerabilities in web applications suggests that programmers are not effectively using those APIs to encode untrusted data. Therefore, we conducted an experimental study with 10 programmers where they attempted to fix XSS vulnerabilities of a web application using the output encoding functionality of OWASP ESAPI. Results revealed 3 types of mistakes that programmers made which resulted in them failing to fix the application by removing XSS vulnerabilities. We also identified 16 usability issues of OWASP ESAPI. We identified that some of these usability issues as the reason for mistakes that programmers made. Based on these results, we provided suggestions on how the usability of output encoding APIs should be improved to give a better experience to programmers

Anthropological gleanings of the work of Martin Wickramasinghe

Martin Wickramasinghe is a prominent figure who contributed to various academic spheres in Sri Lanka. Many who define MartinWickramasinghe only as a creative writer disregards the fact that he was an expert who contributed to a Sri Lankan approach inanthropology. This qualitative research paper analyzes the role of Wickramasinghe in emphasizing the anthropological paradigmsin Sri Lankan society during his period. The main objective of this analysis is to provide a comprehensive insight about the impactand contribution of Martin Wickramasinghe’s work to develop anthropology as an academic discipline in Sri Lanka. For thisresearch, we utilized his publications related to anthropology and culture and analyzed the content which underlined importantanthropological characteristics. His ‘Sathwa Santhathiya’, ‘Sakaskada’, ‘Mānawa Vidyāwa Ha Sinhala Sanskruthiya’, ‘Buddhism and Culture’ are some renowned works that were applied for this study. Wickramasinghe read widely the works of Darwin, Spencer, Huxley as well as the ethnographies of scholars like Malinowski, Ruth Benedict. One of his major views was that Sri Lankan culture was undermined by the conflict with Western culture, and that Buddhism is one of the institutions that protected it from collapse and disappearance. He comparatively expressed his ideas about diffusionism, one of the significant ideas in culturalanthropology, as an ordinary process which takes place in every society. Wickramasinghe related the ideals of democracy,humanism, socialism, religion, and culture to the context of Sri Lanka. This research concludes that Wickramasinghe's interest inanthropology came at a time when anthropology was not popular in Sri Lanka. He has used his knowledge and ideology from records on anthropology to express critical views on the socio-cultural divisions of Sri Lanka, although he cannot be defined as ananthropologist. DOI : http://doi.org/10.31357/fhss/vjhss.v06i02.0

Dialectic nature of digital culture: theoretical analysis of evolutionary 'digital Buddhism' of social media debate

Popular Buddhism is one of the key cultural aspects in present Sri Lankan society.  Its main cause is the characteristics of the path of the Buddhism which it currently travels. Digital anthropology is a field that studies the complex relationships between human culture and the concept of digital. Prominently, digital is a concept based on binary numbers which means 1 and 0. This research aims to provide some insight into the behavior of digital within the social institution of religion. To accomplish these objectives the researchers utilized a Facebook page (Siri Sadaham Ashramaya) and conducted an analysis through the comments from its purposively selected post and it was based on speech act theory elaborated by J. L. Austin (1962) and John Searle (1975). The theoretical approach for this research is the first principle of digital anthropology: dialectic nature of digital culture, developed by Daniel Miller and Heather Horst. A hypothesis was applied as: modern popular Buddhism expand the dialectic nature of culture through social media that consisted of thesis, antithesis, and synthesis as Hegal and Marx stated. The results of the study proved the hypothesis and the opinions of the respective audience’s reactions and comments among the applied Facebook page, and emphasized the dialectical nature of digital culture which means the contribution to the increment of logical background of the culture. Consequently, this study suggests that the modern popular Buddhism concept evolved into a novel concept as “Digital Buddhism” and it can be defined as a new division of Sri Lankan Buddhism as proposed by Gananth Obeyesekere and Richard Gombrich during 1988s. Researchers propose a newly designed model to analyze the digital nature and the theoretical perspective of digital anthropology utilizing the nature of modern popular Buddhism. KEYWORDS:  anthropology, digital, dialectic, popular Buddhism, culture  &nbsp

Exposure risk assessment of polycyclic aromatic Hydrocarbons associated with the indoor air particulate Matters in selected indoor environments in Kandy, Sri Lanka

The present work investigates the health risks associated with the inhalation exposure of particulate bound polyaromatic hydrocarbons in selected indoor environment in Kandy city. Particulate samples from five different types of indoor environments were collected for chemical analysis of 16PAH priority pollutants listed by USEPA. Categorization of locations was based on the degree of urbanization, type of fuel used for cooking and proximity to road from the location. Key meteorological parameters such as wind speed, wind direction, ambient temperature and relative humidity were also measured. The collected samples were analysed using a high performance liquid chromatograph (HPLC), after the necessary extraction and cleaning up of the sample. The total concentrations of particulate PAHs are in the range of 0.386 ng/m3 to 14.65 ng/m3. The comparison of PAH levels at different categories of environment indicate that the degree of urbanization, fuel type and proximity to road influences the total concentrations of particulate PAHs. The dominant particulates of PAHs measured at the selected environments are naphthalene, acenaphthylene, acenaphthene. Then benzo[a]pyrene [B(a)P] indicating particulate PAHs are contributed by a mixture of both diesel and petrol engine type of vehicles, and biomass combustion. The total BaPeq concentrations at different environmental categories ranged from 0.06 to 3.08 ng/m3. The total BaP equivalency results showed the potential health risk to cancer due to inhalation exposure is of concern for residents living in high urban area with usage of wood as fuel. Since the total BaPeq concentrations for this category was higher. Very close to, or slightly exceeded the maximum permissible risk level of 1 ng/m3 of benzo(a)pyrene in other categories also