Air Coupled Impact Echo Testing of Buried Concrete Pipes

Concrete pipes constitute an integral part of the buried infrastructure, and non-destructive testing (NDT) plays an important role in their maintenance effort. Impact echo (IE) is a well-established NDT technique that is widely used for the investigation of concrete structures. In this technique, the thickness (or resonant) frequency is first measured by inducing (compression) P-wave into the structure using an impact source and recording the elastic wave generated using an accelerometer. From the knowledge of P-wave velocity of the medium, the unknown thickness and subsurface defects are then established. To effectively apply this technique, the transducer should be properly coupled with the surface. However, this often becomes a difficult task due to the poor surface quality of concrete. Alternatively, instead of capturing the elastic wave with a contact-based transducer the leaky acoustic wave that accompany the elastic wave is captured with a microphone and the thickness frequency is calculated. This non-contact variation of IE is called the air-coupled IE (ACIE) and it has been shown to be effective for testing plate like concrete structures (e.g., pavements and bride decks). In this dissertation, the feasibility of ACIE for the NDT of buried concrete pipe is investigated. The investigations are conducted in two stages. First, numerical modelling is conducted to test the effectiveness in pipes and then experimental validations are conducted. A structural-acoustic coupled finite element model is created using the COMSOL Multiphysics software, and the propagation of elastic and acoustic waves in a fluid-filled concrete pipe is simulated for standalone and buried pipe. The effectiveness of ACIE is studied when a pipe is surrounded by soil. Two types of soil surrounding the pipe studied to learn more about the quality of the data that might be anticipated from ACIE technique inside the pipe. Using these models, various aspects of ACIE are studied and its performance against the conventional IE is compared. Following the numerical verifications, two laboratory tests setups are constructed with a standalone and buried reinforced concrete pipes (RCP) and ACIE is demonstrated using them. The (unknown) wall thickness is calculated in each case and the results are compared against the conventional contact-based technique. While the presence of soil caused energy losses which affected the amplitude of acoustic wave, it was enough to be detected with good signal to noise ratio. Several enhancements to improve the performance of this technique are studied. For instance, a way to improve the signal-to noise ratio of the acoustic signal is investigated using noise suppressers. For rapid implementation of technique and fast data gathering a semi-automated ACIE setup is also developed. Finally, the ability of the technique to detect several commonly occurring problems in a concrete pipe is investigated. In summary, ACIE technique shows promising results for buried pipe testing

Hypersaline Actinomycetes and Their Biological Applications

Actinomycetes are the potential sources of novel metabolites, therapeutic compounds, enzymes, and other chemicals. Among them, the applications of halophilic actinomycetes toward the medically and industrially important metabolites and enzymes are gaining increasing attention by the scientific community. A large number of novel compounds and enzymes from halophilic actinomycetes have been isolated and characterized from various geographic regions around the world. In this chapter, occurrence, characterization, halotolerant mechanisms, medical importance, metabolites, enzymes, and industrial applications of halophilic actinomycetes are discussed. Halophilic actinomycetes may also serve as good models for the production of important metabolites and enzymes with respect to stress response

Response and resilience of soil microbial communities inhabiting in edible oil stress/contamination from industrial estates

Metagenomic DNA extracted from polluted as well as control soil sample and electrophoresed on 0.8 % agarosa gel. Lane M is of marker, Lane 1, is for polluted sample (representing pooled metagenomic DNA for P1 + P2 + P3 = P) and Lane 2 is for control soil sample (representing pooled metagenomic DNA for C1 + C2 + C3 = C). Figure S2. Distribution of taxa among bacteria at rank phylum classified according to 16S rDNA using RDP classifier for both polluted as well as control sample. Figure S3. Distribution of taxa among bacteria at rank phylum classified according to lowest common ancestor (LCA) for both polluted as well as control sample. Figure S4. Comparative distribution of taxa among bacteria at rank class classified according to WebCARMA and M5NR datasets for both polluted as well as control sample. Table S1. Enzymes mapped for lipid metabolism pathways in KEEG database. (DOC 300 kb

Cultural intelligence and leadership style in the education sector

Purpose: Schools in UAE are multicultural in nature. In this context, cultural intelligence (CQ) is a tool, which can increase an individual’s ability to interact with people outside his/her culture. The purpose of this paper is to explore the perceptions of the school leaders regarding the key influences of cultural intelligence on their ability to adapt their leadership style in the Abu Dhabi Education Sector. Design/methodology/approach: An extensive review of the literature was carried out to acknowledge the cultural intelligence and leadership style adaptability concepts. This research has adopted a qualitative method of inquiry. Data for the study have been collected from three focus groups with 14 schools leaders in the Emirate of Abu Dhabi. Findings: This pilot study reveals that cultural intelligence has some influence on the school leaders’ ability to adapt their leadership style within a diverse work environment. This influence is complex in nature and multiple factors have been identified. Research limitations/implications: The main limitations of this study are associated with the small sample size. Regarding the implications, while this study was conducted in a UAE cultural context, it can be extended to other Gulf countries. Future research should prompt educational leaders, administrators, students, and research academics to further consider the impact of cultural intelligence on leadership style. Practical implications: This study contributes towards cultural intelligence literature. Schools should provide cultural training to managers before appointing them to leadership positions, which helps in understanding the culture which they are going to operate in, and effectively manage their drives, workforce, students, and the community. Originality/value: The paper highlights six core factors that influence the ability of school leaders to adapt their leadership style in culturally diverse environments. These preliminary factors need to be examined further to validate the dimensions of leadership adaptability in various contexts

DIGITAL AGRICULTURE: ANALYSIS OF VIBRATION TRANSMISSION FROM SEAT TO BACK OF TRACTOR DRIVERS UNDER MULTI-DIRECTIONAL VIBRATION CONDITIONS

The present research examines the impact of vibrations on seat-to-back transmissibility in tractor drivers. This study utilized a smart device for real-time data transmission to improve the experimentation by eliminating potential sources of error. Data was assessed using metrics such as weighted acceleration, daily exposure, power spectral density, and seat-to-back transmissibility. The seat pan and backrest were found to have high vibration levels on the vertical axis. Daily exposure response exceeded the exposure action limit of 0.5 m/s2, as specified in Directive 2002/44/EU. Power spectral densities at the seat pan and the backrest revealed dominant frequencies in the low-frequency range. Seat-to-back transmissibility demonstrated primary and secondary resonance within the 4.1-7.2 Hz and 8.2-11.8 Hz frequency ranges. Tractor manufacturers and designers could utilize the findings of this study to decrease the excessive vibration intensities and crucial resonating frequencies and thus enhance the operator's ride comfort

Flavonoids: Anticancer Properties

Flavonoids are plant secondary metabolites. They are mainly classified into four major groups, such as flavanols, flavones, anthocyanidins, and isoflavonoids. Furthermore, they are divided into some subclasses. They are available in dietary foods and they cure various diseases. Certain plants and spices contain flavonoids, which have been commonly used for thousands of years in traditional medicine. Some of the flavonoids have been clinically used in many countries. Baicalein and its glycosides are one among them to have been experimented clinically. Flavonoids have the capability to regulate cell division and proliferation in an important pathway. They have medicinal activities including anticancer properties. The isoflavone analog rotenone is one of the flavonoid compounds, which has been revealed to be actual anticancer agent. Scutellaria species having flavones retain cytotoxic activities against many human cancer cell lines. At the same time, they do not harm the myeloid cells, normal peripheral and normal epithelial blood cells. Epidemiological studies also confirmed that the intake of dietary flavonoids reduces a risk condition in cancer

Melanin-templated rapid synthesis of silver nanostructures

BACKGROUND: As a potent antimicrobial agent, silver nanostructures have been used in nanosensors and nanomaterial-based assays for the detection of food relevant analytes such as organic molecules, aroma, chemical contaminants, gases and food borne pathogens. In addition silver based nanocomposites act as an antimicrobial for food packaging materials. In this prospective, the food grade melanin pigment extracted from sponge associated actinobacterium Nocardiopsis alba MSA10 and melanin mediated synthesis of silver nanostructures were studied. Based on the present findings, antimicrobial nanostructures can be developed against food pathogens for food industrial applications. RESULTS: Briefly, the sponge associated actinobacterium N. alba MSA10 was screened and fermentation conditions were optimized for the production of melanin pigment. The Plackett-Burman design followed by a Box-Behnken design was developed to optimize the concentration of most significant factors for improved melanin yield. The antioxidant potential, reductive capabilities and physiochemical properties of Nocardiopsis melanin was characterized. The optimum production of melanin was attained with pH 7.5, temperature 35°C, salinity 2.5%, sucrose 25 g/L and tyrosine 12.5 g/L under submerged fermentation conditions. A highest melanin production of 3.4 mg/ml was reached with the optimization using Box-Behnken design. The purified melanin showed rapid reduction and stabilization of silver nanostructures. The melanin mediated process produced uniform and stable silver nanostructures with broad spectrum antimicrobial activity against food pathogens. CONCLUSIONS: The melanin pigment produced by N. alba MSA10 can be used for environmentally benign synthesis of silver nanostructures and can be useful for food packaging materials. The characteristics of broad spectrum of activity against food pathogens of silver nanostructures gives an insight for their potential applicability in incorporation of food packaging materials and antimicrobials for stored fruits and foods

CYTOTOXIC AND ANTIOXIDANT PROPERTIES OF FRACTIONS ISOLATED FROM FERONIA ELEPHANTUM

Objective: The leaves of Feronia elephantum are widely used in folk medicine in India to treat various ailments. In the present communication we report the cytotoxic and antioxidant properties of extracts and fractions of F. elephantum leaves. Methods: The leaves of F. elephantum were extracted with hexane and ethyl acetate and checked for cytotoxic properties against human A549 lung adenocarcinoma cancer cell line. The active extract was subjected to column chromatography and fractions were bio-assayed. The active fraction was subjected to GC-MS analysis. Results: Hexane extract exhibited good cytotoxic activity against A549 lung cancer cell line compared to ethyl acetate extract. Hexane extract showed 77.3% activity at the dose of 500 µg/mL with IC50 (50.6%) value of 125 µg/mL. Hexane extract was also tested at different time intervals of 12h, 24h, 48h and 72 h. The activity gradually increased. The active hexane extract was subjected to column chromatography. Based on thin layer chromatography profiles, similar fractions were combined to give 9 fractions. When the fractions were bio-assayed fraction 5 showed maximum cytotoxic activity. Fraction 5 was tested against A549 lung cancer cell line at different time intervals; the activity gradually increased. Fraction 5 was used to test the antioxidant properties using DPPH analysis. Maximum antioxidant activity was observed at 1000 µg/mL (71.63 ± 0.15). Active fraction 5 was identified using GC-MS. It showed the presence of Estragole (50.82%), trans-anethole (p-propenylanisole, anise camphor) (14.98%) and Caryophyllene (9.22%). Conclusion: The results showed that hexane extract of F. elephantum could be probed further in drug discovery programme

Cow Dung Is a Novel Feedstock for Fibrinolytic Enzyme Production from Newly Isolated Bacillus sp. IND7 and Its Application in In Vitro Clot Lysis

Bacterial fibrinolytic enzymes find great applications to treat and prevent cardiovascular diseases. The novel fibrinolytic enzymes from food grade organisms are useful for thrombolytic therapy. This study reports fibrinolytic enzyme production by Bacillus sp. IND7 in solid-state fermentation (SSF). In this study, cow dung was used as the cheap substrate for the production of fibrinolytic enzyme. Enzyme production was primarily improved by optimizing the nutrient and physical factors by one-variable-at-a-time approach. A statistical method (two-level full factorial design) was applied to investigate the significant variables. Of the different variables, pH, starch, and beef extract significantly influenced on the production of fibrinolytic enzyme (p < 0.05). The optimum levels of these significant factors were further investigated using response surface methodology. The optimum conditions for enhanced fibrinolytic enzyme production were 1.23% (w/w) starch and 0.3 % (w/w) beef extract with initial medium pH 9.0. Under the optimized conditions, cow dung substrate yielded 8,345 U/g substrate, and an overall 2.5-fold improvement in fibrinolytic enzyme production was achieved due to its optimization. This is the first report of fibrinolytic enzyme production using cow dung substrate from Bacillus sp. in SSF. The crude enzyme displayed potent activity on zymography and digested goat blood clot completely in in vitro condition