1,321 research outputs found

    Combined adsorption and oxidation technique for waste water treatment: potential application in permeable reactive barrier

    Get PDF
    This dissertation explores a combined adsorption and advanced oxidation technology for trapping and destruction of organic pollutants in waste water. The adsorbed/immobilized pollutant onto the surface of metal supported catalyst is oxidized via advanced oxidation technology. The advanced oxidation process is carried out using Co[superscript]2+/KHSO[subscript]5 (Cobalt/peroxymonosulphate) reagent to generate highly active sulphate radical (SO[subscript]4*), which can readily attack and oxidize the organic pollutants in waste water. The reaction mechanism of Co[superscript]2+/KHSO[subscript]5 reagent follows similarly to the Fenton reagent (Fe[superscript]2+/H[subscript]2O[subscript]2) which is used to generate hydroxyl radical (OH*). Co[superscript]2+/KHSO[subscript]5 reagent has been successfully utilized for bleaching applications and oxidation of organic contaminants. Compared to hydroxyl radical, the sulphate radical is highly potent to oxidize contaminants even at basic pH. However the biggest disadvantage of using Co[superscript]2+/KHSO[subscript]5 reagent is the dissolution of Co[superscript]2+ ion into the water which poses a severe environmental hazard. In the current study, cobalt ion is incorporated into supporting media and utilized for advanced oxidation.Very few studies have so far explored the heterogeneous oxidation technology based on Co[superscript]2+/KHSO[subscript]5 for the treatment of organic contaminants in water. With this research focus, various support media have been utilized to load cobalt ions, which included Zeolite A, Zeolite X, ZSM-5, SBA-15, Silica and Activated Carbon. Cobalt metal was incorporated into commercial Zeolites by ion exchange technique whereas in-situ cobalt loading was carried out during the synthesis of SBA-15. Cobalt loading was done into Silica and Activated Carbon by conventional impregnation technique. The choice of cobalt loading technique inherently determines the oxidation state of cobalt species loaded into the sample which in turn determines the oxidation efficiency. Furthermore, the choice of cobalt precursor significantly affects the metal-support bonding which has been investigated by loading on silica support with different types of cobalt precursor such as cobalt chloride, cobalt acetate and cobalt nitrate. Many of these supports such as Zeolite ZSM-5 and Activated Carbon have never been tested before for cobalt loading and oxidation via sulphate based oxidant and demonstrate efficient oxidation of phenolic pollutants.The investigation of organic oxidation using sulphate based oxidants was further extended into photocatalytic reactions. Photo degradation was carried out using artificial solar light and germicidal UV radiation in the presence of ZnO and oxidants such as peroxymonosulphate, peroxidisulphate and hydrogen peroxide. The comparison of photochemical and photocatalytic oxidation was carried out and their synergy of combination was explored.The thesis provides a thorough exploration of heterogeneous oxidation via sulphate based oxidant for the treatment of organic pollutants. The supported catalysts investigated here can be further improved and utilized as a PRB media for groundwater remediation. A final chapter discusses about the mathematical modeling of a column test to mimic a lab scale PRB in order to investigate the process parameters affecting the PRB design. The column modeling also directs towards a development of a novel “Reactive Adsorber” for the treatment of industrial waste by combined adsorption and oxidation

    Thermoplastics Foams: An Automotive Perspective

    Get PDF
    The automotive industry has witnessed a massive shift in terms of materials used, ranging from being a metallic heavyweight in the 1950s to employing a hybrid sandwich of multiple material systems. This apparent shift can be attributed to achieving improvements in performance, safety and fuel efficiency, along with responding to the various environmental regulations imposed by different governments. The recent advocacy of Corporate Average Fuel Economy (CAFE) standard of 54.5 MPG by 2025 by the US Environmental Protection Agency (EPA) to reduce greenhouse gas (GHG) emissions [1] has spurred the sector at large towards the use of lightweight materials

    The autotaxin-LPA2 GPCR axis is modulated by γ-irradiation and facilitates DNA damage repair

    Get PDF
    In this study we characterized the effects of radiation injury on the expression and function of the autotaxin (ATX)-LPA2 GPCR axis. In IEC-6 crypt cells and jejunum enteroids quantitative RT-PCR showed a time- and dose-dependent upregulation of lpa2 in response to γ-irradiation that was abolished by mutation of the NF-κB site in the lpa2 promoter or by inhibition of ATM/ATR kinases with CGK-733, suggesting that lpa2 is a DNA damage response gene upregulated by ATM via NF-κB. The resolution kinetics of the DNA damage marker γ-H2AX in LPA-treated IEC-6 cells exposed to γ-irradiation was accelerated compared to vehicle, whereas pharmacological inhibition of LPA2 delayed the resolution of γ-H2AX. In LPA2-reconstituted MEF cells lacking LPA1&3 the levels of γ-H2AX decreased rapidly, whereas in Vector MEF were high and remained sustained. Inhibition of ERK1&2 or PI3K/AKT signaling axis by pertussis toxin or the C311A/C314A/L351A mutation in the C-terminus of LPA2 abrogated the effect of LPA on DNA repair. LPA2 transcripts in Lin(-)Sca-1(+)c-Kit(+) enriched for bone marrow stem cells were 27- and 5-fold higher than in common myeloid or lymphoid progenitors, respectively. Furthermore, after irradiation higher residual γ-H2AX levels were detected in the bone marrow or jejunum of irradiated LPA2-KO mice compared to WT mice. We found that γ-irradiation increases plasma ATX activity and LPA level that is in part due to the previously established radiation-induced upregulation of TNFα. These findings identify ATX and LPA2 as radiation-regulated genes that appear to play a physiological role in DNA repair

    Foreign body rectum: A case report

    Get PDF
    Rectal foreign bodies are confronted frequently in a surgical emergency. These are often related to sexual behaviour. Due to the fear of social embarrassment, patients tend to hide the facts associated with the incident and present late. Because of the serious complications, foreign body rectum should be considered as an emergency and managed in a well-organised manner. Diagnosis can be made by clinical and radiological examination. In the majority of cases, the transanal approach is successful. Laparotomy is reserved for cases with perforation or peritonitis. Here, we report the case of a 24-year-old male who inserted an electrical beard trimmer in his rectum under alcohol intoxication. Since transanal removal failed, emergency laparotomy with successful removal of foreign body was done

    In vitro effect of polyethylene glycol and sorbitol on two banana varieties viz. Grand naine and Nalla bontha to study drought stress

    Get PDF
    Water stress is one of the foremost categories of stress damaging plants’ overall growth and development. The aim of the present study was to explore and demonstrate stress-induced drought to calibrate changes in stress parameters of two banana plant varieties viz. Grand naine (G9)  and Nalla bontha were cultured in Murashige and Skoog medium (MS) media supplemented with stress inducers -Poly ethylene glycol (PEG)  and sorbitol. The different concentrations of inducers were used to induce drought stress in two varieties of banana with contrasting characters for drought condition. The study indicated that PEG contrived mild to moderate osmotic stress and so does the alditol i.e. sorbitol on in vitro banana plants.  The different concentrations of PEG and sorbitol produced significant effects on various parameters. The maximum decrease in shoot length was prominent in G9(52%) as compared to Nalla bontha (11%). When treated with 3% w/v sorbitol, even average root length showed the same level of damage with G9(59%) while in case of Nalla bontha there  was  a 17% decrease. The banana plantlet produced in vitro was estimated at one and two weeks after inoculation, respectively. Proline content tended to increase as the concentration of osmotic inducers increased (-44 % in G9 at 3% w/v sorbitol), whereas RWC (8.9% in G9 at 3% w/v Peg) showed an opposite effect. It was concluded that quantitative and qualitative changes in physiological (shoot and root length) and biochemical (Proline and relative water content, RWC) parameters played an important role in plants under drought stress conditions. This pattern varied from species to species. This work has been attempted for the first time in banana, especially Grand naine varieties with contrasting characters under induced drought stress.

    Contextually balanced engagement:Navigating paradoxes of localisation and cultural embedding in rural health information systems implementation

    Get PDF
    Although health information systems (HIS) play an important role in elevating health standards, a comprehensive understanding of how to effectively implement HIS in rural areas is lacking. This issue becomes more significant when considering that globally a majority of the approximately 1.5 million deaths of children under the age of five in 2019 that were attributable to vaccine-preventable diseases occurred in rural areas. Accordingly, we ask two questions. How does rurality influence the implementation of information and communication technology for development (ICT4D) projects? How do organisations navigate challenges associated with rurality during the implementation of these projects? Our findings, derived from an in-depth case study of a social enterprise in rural India, reveal two paradoxes that pose challenges to the effective implementation of HIS in rural settings: the localisation paradox and the cultural embedding paradox. We found that contextually balanced engagement was comprised of four organisational responses—prioritising; localising; cultural adjustment; and engaging stakeholders—that help navigate the challenges posed by the localisation and cultural embedding paradoxes. Synthesising these findings, we develop a process model that shows how the implementation of HIS in rural areas is shaped by the descriptive and sociocultural characteristics of rurality. Further, organisations require a dynamic approach, engaging in multiple responses over time to navigate the paradoxes inherent in HIS implementation. We suggest that organisational responses to paradoxical tensions stemming from the descriptive and sociocultural characteristics of rurality lead to the development of HIS enabled for rurality. Our findings contribute the understanding of ICT4D projects implementation.</p

    Impact of Accreditation on Quality and Excellence of Higher Education Institutions

    Get PDF
    Higher education plays a crucial role in the growth and nation development in social, economic, cultural, scientific and political respects. Education empowers people to transform from a human being to having human resources. In present context of globalization, quality higher education is needed to uplift creativity, talent, adaptability and research mindset. In order to fully utilize the outcomes of education, it is important to ensure that education is meeting the minimal prescribed standards to fulfill ever-changing requirements worldwide. Accreditation, a powerful tool of quality assurance, is used to assess the national system of higher education. Accreditation is considered as a quality stamp, which ensures that an accredited institution/programme has undergone a rigorous process of external peer evaluation based on predefined standards/principles and complies with the minimum requirements. This paper focuses on the outcomes of accreditation to enhance excellence in higher education institutions (HEIs) based on a literature review and empirical research. Previous studies in various national contexts are reviewed here, based on which, the question of whether accreditation can really enhance the excellence of HEIs is answered and factors behind it are explored
    corecore