Search results for: multi band antenna
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5139

Search results for: multi band antenna

1239 Mode of Action of Surface Bound Antimicrobial Peptides Melimine and Mel4 against Pseudomonas aeruginosa

Authors: Muhammad Yasir, Debarun Dutta, Mark Willcox

Abstract:

Biomaterial-associated infections are a multi-billion dollar burden globally. Antimicrobial peptide-based coatings may be able to prevent such infections. The aim of this study was to investigate the mechanism of action surface bound peptides (AMPs) against Pseudomonas aeruginosa 6294. Melimine and Mel4 were covalently attached to glass coverslips using azido-benzoic acid. Attachment was confirmed using X-ray photoelectron spectroscopy. P. aeruginosa was allowed to attach to AMP-coated glass for up to 6 hours. The effect of the surface-bound AMPs on bacterial cell membranes was evaluated using the dyes DiSC3-(5), Sytox green, SYTO 9 and propidium iodide with fluorescence microscopy. Release of cytoplasmic materials ATP and DNA/RNA were determined in the surrounding fluid. The amount of cell death was estimated by agar plate counts. The AMPs were successfully covalently bound to the glass as demonstrated by increases in %nitrogen of 3.6% (melimine) and 2.3% (Mel4) compared to controls. Immobilized peptides disrupted the cytoplasmic membrane potential of P. aeruginosa within 10 min. This was followed by the release of ATP after 2 h. Membrane permeabilization started at 3 h of contact with glass coated AMPs. There was a significant number of bacteria (59% for melimine; 36% for Mel-4) with damaged membranes after 4 h of contact. At the 6 h time point, release of DNA occurred with melimine releasing 2 times the amount of DNA/RNA than Mel4 surfaces (p < 0.05). Surface bound AMPs were able to disrupt cell membranes with subsequent release of cytoplasmic materials, and ultimately resulting in bacterial death.

Keywords: biomaterials, immobilized antimicrobial peptides, P. aeruginosa, mode of action

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1238 Possible Management of Acute Liver Failure Caused Experimentally by Thioacetamide Through a Wide Range of Nano Natural Anti-Inflammatory And Antioxidants Compounds [Herbal Approach]

Authors: Sohair Hassan, Olfat Hammam, Sahar Hussein, Wessam Magdi

Abstract:

Objective: Acute liver failure (ALF) is a clinical condition with an unclear history of pathophysiology, making it a challenging task for scientists to reverse the disease in its initial phase and to help the liver re-function customary: this study aimed to estimate the hepatoprotective effects of Punica granatum Lpeel and Pistacia atlantica leaves as a multi-rich antioxidants ingredients either in their normal and/or in their nanoforms against thioacetamide induced acute liver failure in a rodent model. Method: Male Wistar rats (n=60) were divided into six equal groups, the first group employed as a control; The second group administered a dose of 350 mg /Kg/ b.w of thioacetamide (TAA)-IP, from the third to the sixth group received TAA + [2mls / 100 g b.w/d] of aqueous extracts of Punica granatum L and Pistacia atlantica either in their normal and/or Nano forms consecutively for (14 days) Results: Recorded significant elevation in liver enzymes, lipid profiles, LPO (p= 0.05) and NO with a marked significant decrease in GSH and SOD accompanied by an elevation in inflammatory cytokine (IL6, TNF-α, and AFP) in addition to a noticeable increase in HSP70 level & degradation in DNA respectively in TAA challenged group. However significant and subsequent amelioration of most of the impaired markers was observed with ip nano treatment of both extracts. Conclusion: The current results highlighted the high performance of both plant nano extracts and their hepatoprotective impact and their possible therapeutic role in the amelioration of TAA induced acute liver failure in experimental animals.

Keywords: acute liver failure HPLC, IL6, nano extracts, thioacetamide, TNF-α

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1237 Electrochemical Recovery of Lithium from Geothermal Brines

Authors: Sanaz Mosadeghsedghi, Mathew Hudder, Mohammad Ali Baghbanzadeh, Charbel Atallah, Seyedeh Laleh Dashtban Kenari, Konstantin Volchek

Abstract:

Lithium has recently been extensively used in lithium-ion batteries (LIBs) for electric vehicles and portable electronic devices. The conventional evaporative approach to recover and concentrate lithium is extremely slow and may take 10-24 months to concentrate lithium from dilute sources, such as geothermal brines. To response to the increasing industrial lithium demand, alternative extraction and concentration technologies should be developed to recover lithium from brines with low concentrations. In this study, a combination of electrocoagulation (EC) and electrodialysis (ED) was evaluated for the recovery of lithium from geothermal brines. The brine samples in this study, collected in Western Canada, had lithium concentrations of 50-75 mg/L on a background of much higher (over 10,000 times) concentrations of sodium. This very high sodium-to-lithium ratio poses challenges to the conventional direct-lithium extraction processes which employ lithium-selective adsorbents. EC was used to co-precipitate lithium using a sacrificial aluminium electrode. The precipitate was then dissolved, and the leachate was treated using ED to separate and concentrate lithium from other ions. The focus of this paper is on the study of ED, including a two-step ED process that included a mono-valent selective stage to separate lithium from multi-valent cations followed by a bipolar ED stage to convert lithium chloride (LiCl) to LiOH product. Eventually, the ED cell was reconfigured using mono-valent cation exchange with the bipolar membranes to combine the two ED steps in one. Using this process at optimum conditions, over 95% of the co-existing cations were removed and the purity of lithium increased to over 90% in the final product.

Keywords: electrochemical separation, electrocoagulation, electrodialysis, lithium extraction

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1236 Migrant Labour in Kerala: A Study on Inter-State Migrant Workers

Authors: Arun Perumbilavil Anand

Abstract:

In the recent years, Kerala is witnessing a large inflow of migrants from different parts of the country. Though initially, the migrants were largely from the districts of Tamil Nadu and mostly of seasonal nature, but at a later period, the state started getting migrants from the far-off states like UP, Assam, Bengal, etc. Higher wages for unskilled labour, large opportunities for employment, the reluctance on the part of Kerala workers to do menial and hard physical work, and the shortage of local labour, paradoxically despite the high unemployment rate in the state, led to the massive influx of migrant labourers. This study takes a multi-dimensional overview of migrant labour in Kerala by encompassing factors such as channels of migration, nature of employment contracts entered into and the corresponding wages and benefits obtained by them. The study also analysed the circumstances that led to the large influx of migrants from different states of India. It further makes an attempt to examine the varying dimensions of living and working environment, and also the health conditions of migrants. The study is based on the empirical findings obtained as a result of the primary interviews conducted with migrants in the districts of Palakkad, Malappuram, and Ernakulam. The study concludes by noting that Kerala will inevitably have to depend on migrant labour and is likely to experience heavy in-migration of labour in future, provided that if the existing socioeconomic and demographic situations persist. Since, this is inevitable, the best way before the state is to prepare well in advance to receive and accommodate such migrant labour to lead a comfortable life in a hassle free environment, so that it would definitely play a vital role in further strengthening and sustaining the growth trajectory of not only Kerala’s economy but also the states of origin.

Keywords: Kerala, labour, migration, migrant workers

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1235 Cost Benefit Analysis of Adoption of Climate Change Adaptation Options among Rural Rice Farmers in Nepal

Authors: Niranjan Devkota , Ram Kumar Phuya, Durga Lal Shreshta

Abstract:

This paper estimates cost and benefit of adoption of climate change adaptation options available to the rural rice farmers of Nepal. Adoption of adaptation strategies, intensity of use of adaptation options, identification of labor and non-labor cost and finally per unit cost and benefit analysis of climate change adaptation were made. Multi-stage sampling technique was used to source respondents for the study and used structured questionnaire techniques to collect data from 773 households from seven districts; 3 from Terai and 4 from Hilly region of Nepal. The result revealed that there are 13 major adaptation options rice farmers practice in order to protect themselves from climatic risk. Among the given adaptation options, the first three popular adaptation options practiced by rice farmers are (i) increasing use of chemical fertilizer (60.93%) (ii) use of climate smart verities (49.29%) and (iii) change in nursery date (32.08%). Adaptation cost is obvious, based on that, the first three costly adaptation options are the alternative irrigation practice which incurred average cost of US $69.95 (US$ 1 = 102.84 Nepalese Rupees) followed by a denser plantation of local seeds ($ 20.69) and using climate smart varieties ($ 18.06). 88% farmers practiced more than one adaptation strategies on the same farm with the aim of reducing the effect of extreme climatic conditions. Total cost and revenue revealed that per unit total cost ranges from $28.34 to $32.79 whereas per unit total revenue ranges $33.4 to $49.02. Surprisingly, it is observed that farmers who do not adopt any adaptation options are able to receive highest income from per unit production. As Net Present Value (NPV) is positive and Benefit Cost Ration (BCR) is greater than one for every adaptation options that indicates the available adaptation options are profitable to the rice farmers.

Keywords: climate change, adaptation options, cost benefit analysis, rural rice farmers, Nepal

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1234 Screening and Isolation of Lead Molecules from South Indian Plant Extracts against NDM-1 Producing Escherichia coli

Authors: B. Chandar, M. K. Ramasamy, P. Madasamy

Abstract:

The discovery and development of newer antibiotics are limited with the increase in resistance of such multi-drug resistant bacteria creating the need for alternative new therapeutic agents. The recently discovered New Delhi Metallo-betalactamase-1 (NDM-1), which confers antibiotic resistance to most of the currently available β-lactams, except colistin and tigecycline, is a global concern. Several antibacterial drugs approved are natural products or their semisynthetic derivatives, but plant extracts remain to be explored to find molecules that are effective against NDM-1 bacteria. Therefore, it is necessary to explore the possibility of finding new and effective antibacterial compounds against NDM-1 bacteria. In the present study, we have screened a diverse set South Indian plant species, and report most plant species as a potential source for antimicrobial compounds against NDM-1 bacteria. Ethanol extracts from the leaves of taxonomically diverse South Indian medicinal plants were screened for antibacterial activity against NDM-1 E. coli using streak plate method. Among the plant screened against NDM-1 E. coli, the ethanol extracts from many plant extracts showed minimum bactericidal concentration between 5 and 15 mg /ml and MIC between 2.54 and 5.12 mg/ml. These extracts also showed a potent synergistic effect when combined with antibiotics colistin and tetracycline. Combretum albidum that was effective was taken for further analysis. At 5mg/L concentration, these extracts inhibited the NDM-1 enzyme in vitro, and residual activity for Combretum albidum was 33.09%. Treatment of NDM-1 E. coli with the extracts disrupted the cell wall integrity and caused 89.7% cell death. The plant extract of Combretum albidum that was effective was subjected to fractionation and the fraction was further subjected to HPLC, LC-MS for identification of antibacterial compound.

Keywords: antibacterial activity, combretum albidum, Escherichia coli, NDM-1

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1233 Photonic Dual-Microcomb Ranging with Extreme Speed Resolution

Authors: R. R. Galiev, I. I. Lykov, A. E. Shitikov, I. A. Bilenko

Abstract:

Dual-comb interferometry is based on the mixing of two optical frequency combs with slightly different lines spacing which results in the mapping of the optical spectrum into the radio-frequency domain for future digitizing and numerical processing. The dual-comb approach enables diverse applications, including metrology, fast high-precision spectroscopy, and distance range. Ordinary frequency-modulated continuous-wave (FMCW) laser-based Light Identification Detection and Ranging systems (LIDARs) suffer from two main disadvantages: slow and unreliable mechanical, spatial scan and a rather wide linewidth of conventional lasers, which limits speed measurement resolution. Dual-comb distance measurements with Allan deviations down to 12 nanometers at averaging times of 13 microseconds, along with ultrafast ranging at acquisition rates of 100 megahertz, allowing for an in-flight sampling of gun projectiles moving at 150 meters per second, was previously demonstrated. Nevertheless, pump lasers with EDFA amplifiers made the device bulky and expensive. An alternative approach is a direct coupling of the laser to a reference microring cavity. Backscattering can tune the laser to the eigenfrequency of the cavity via the so-called self-injection locked (SIL) effect. Moreover, the nonlinearity of the cavity allows a solitonic frequency comb generation in the very same cavity. In this work, we developed a fully integrated, power-efficient, electrically driven dual-micro comb source based on the semiconductor lasers SIL to high-quality integrated Si3N4 microresonators. We managed to obtain robust 1400-1700 nm combs generation with a 150 GHz or 1 THz lines spacing and measure less than a 1 kHz Lorentzian withs of stable, MHz spaced beat notes in a GHz band using two separated chips, each pumped by its own, self-injection locked laser. A deep investigation of the SIL dynamic allows us to find out the turn-key operation regime even for affordable Fabry-Perot multifrequency lasers used as a pump. It is important that such lasers are usually more powerful than DFB ones, which were also tested in our experiments. In order to test the advantages of the proposed techniques, we experimentally measured a minimum detectable speed of a reflective object. It has been shown that the narrow line of the laser locked to the microresonator provides markedly better velocity accuracy, showing velocity resolution down to 16 nm/s, while the no-SIL diode laser only allowed 160 nm/s with good accuracy. The results obtained are in agreement with the estimations and open up ways to develop LIDARs based on compact and cheap lasers. Our implementation uses affordable components, including semiconductor laser diodes and commercially available silicon nitride photonic circuits with microresonators.

Keywords: dual-comb spectroscopy, LIDAR, optical microresonator, self-injection locking

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1232 Configuring Systems to Be Viable in a Crisis: The Role of Intuitive Decision-Making

Authors: Ayham Fattoum, Simos Chari, Duncan Shaw

Abstract:

Volatile, uncertain, complex, and ambiguous (VUCA) conditions threaten systems viability with emerging and novel events requiring immediate and localized responses. Such responsiveness is only possible through devolved freedom and emancipated decision-making. The Viable System Model (VSM) recognizes the need and suggests maximizing autonomy to localize decision-making and minimize residual complexity. However, exercising delegated autonomy in VUCA requires confidence and knowledge to use intuition and guidance to maintain systemic coherence. This paper explores the role of intuition as an enabler of emancipated decision-making and autonomy under VUCA. Intuition allows decision-makers to use their knowledge and experience to respond rapidly to novel events. This paper offers three contributions to VSM. First, it designs a system model that illustrates the role of intuitive decision-making in managing complexity and maintaining viability. Second, it takes a black-box approach to theory development in VSM to model the role of autonomy and intuition. Third, the study uses a multi-stage discovery-oriented approach (DOA) to develop theory, with each stage combining literature, data analysis, and model/theory development and identifying further questions for the subsequent stage. We synthesize literature (e.g., VSM, complexity management) with seven months of field-based insights (interviews, workshops, and observation of a live disaster exercise) to develop a framework of intuitive complexity management framework and VSM models. The results have practical implications for enhancing the resilience of organizations and communities.

Keywords: Intuition, complexity management, decision-making, viable system model

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1231 Quince Seed Mucilage (QSD)/ Multiwall Carbonano Tube Hybrid Hydrogels as Novel Controlled Drug Delivery Systems

Authors: Raouf Alizadeh, Kadijeh Hemmati

Abstract:

The aim of this study is to synthesize several series of hydrogels from combination of a natural based polymer (Quince seed mucilage QSD), a synthetic copolymer contained methoxy poly ethylene glycol -polycaprolactone (mPEG-PCL) in the presence of different amount of multi-walled carbon nanotube (f-MWNT). Mono epoxide functionalized mPEG (mP EG-EP) was synthesized and reacted with sodium azide in the presence of NH4Cl to afford mPEG- N3(-OH). Then ring opening polymerization (ROP) of ε–caprolactone (CL) in the presence of mPEG- N3(-OH) as initiator and Sn(Oct)2 as catalyst led to preparation of mPEG-PCL- N3(-OH ) which was grafted onto propagylated f-MWNT by the click reaction to obtain mPEG-PCL- f-MWNT (-OH ). In the presence of mPEG- N3(-Br) and mixture of NHS/DCC/ QSD, hybrid hydrogels were successfully synthesized. The copolymers and hydrogels were characterized using different techniques such as, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The gel content of hydrogels showed dependence on the weight ratio of QSD:mPEG-PCL:f-MWNT. The swelling behavior of the prepared hydrogels was also studied under variation of pH, immersion time, and temperature. According to the results, the swelling behavior of the prepared hydrogels showed significant dependence in the gel content, pH, immersion time and temperature. The highest swelling was observed at room temperature, in 60 min and at pH 8. The loading and in-vitro release of quercetin as a model drug were investigated at pH of 2.2 and 7.4, and the results showed that release rate at pH 7.4 was faster than that at pH 2.2. The total loading and release showed dependence on the network structure of hydrogels and were in the range of 65- 91%. In addition, the cytotoxicity and release kinetics of the prepared hydrogels were also investigated.

Keywords: antioxidant, drug delivery, Quince Seed Mucilage(QSD), swelling behavior

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1230 Seismic Reflection Highlights of New Miocene Deep Aquifers in Eastern Tunisia Basin (North Africa)

Authors: Mourad Bédir, Sami Khomsi, Hakim Gabtni, Hajer Azaiez, Ramzi Gharsalli, Riadh Chebbi

Abstract:

Eastern Tunisia is a semi-arid area; located in the northern Africa plate; southern Mediterranean side. It is facing water scarcity, overexploitation, and decreasing of water quality of phreatic water table. Water supply and storage will not respond to the demographic and economic growth and demand. In addition, only 5 109 m3 of rainwater from 35 109 m3 per year renewable rain water supply can be retained and remobilized. To remediate this water deficiency, researches had been focused to near new subsurface deep aquifers resources. Among them, Upper Miocene sandstone deposits of Béglia, Saouaf, and Somaa Formations. These sandstones are known for their proven Hydrogeologic and hydrocarbon reservoir characteristics in the Tunisian margin. They represent semi-confined to confined aquifers. This work is based on new integrated approaches of seismic stratigraphy, seismic tectonics, and hydrogeology, to highlight and characterize these reservoirs levels for aquifer exploitation in semi-arid area. As a result, five to six third order sequence deposits had been highlighted. They are composed of multi-layered extended sandstones reservoirs; separated by shales packages. These reservoir deposits represent lowstand and highstand system tracts of these sequences, which represent lowstand and highstand system tracts of these sequences. They constitute important strategic water resources volumes for the region.

Keywords: Tunisia, Hydrogeology, sandstones, basin, seismic, aquifers, modeling

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1229 Voices of the Grown-Ups: Transnational Rearing among Chinese Families

Authors: Laura Lamas Abraira

Abstract:

Large-scale Chinese immigration in Spain emerged in the 80's. Engaged in their own businesses or working for other Chinese migrants with long schedules, young couples had to choose between contracting or transnationalising the care labour as they were unable to combine productive and reproductive tasks. In most cases, they decided to transnationalize the care labour embodied on grandparents or children migratory paths. Either the grandparents go to Spain to take care of their grandchildren or the kids were left behind or sent to China after being born in Spain in order to be raised with their extended family members. Very little is known about how the people who have been raised in a transnational context relates their own experience and agency as care managers within the family care cycle. In order to fill this gap, this paper aims to inquire into these transnationally-reared Chinese young adults’ narratives about their own experience and expectations (past, present and future) by adopting care circulation and care cycle approach within life course framework. Drawing upon a qualitative study resulting from a multi-sited ethnography (Spain-China), we argue that young adults raised in transnational context build their narratives as a result of an otherness process related to their parents and an essentialization of their Chinese roots to use selectively among different contexts. In doing so, these family narratives constitute a part of their social identity that interact with other dimensions such as the ethnic one. We suggest when building their parent's otherness they also build their sameness among pairs, as members of the same club, marked by transnational care on a double time basis: the practices of their parents as wrong past, and their own as an amendable future.

Keywords: Chinese families, narratives, transnational care, young adults

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1228 Orientia Tsutsugamushi an Emerging Etiology of Acute Encephalitis Syndrome in Northern Part of India

Authors: Amita Jain, Shantanu Prakash, Suruchi Shukla

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Introduction: Acute encephalitis syndrome (AES) is a complex multi etiology syndrome posing a great public health problem in the northern part of India. Japanese encephalitis (JE) virus is an established etiology of AES in this region. Recently, Scrub typhus (ST) is being recognized as an emerging aetiology of AES in JE endemic belt. This study was conducted to establish the direct evidence of Central nervous system invasion by Orientia tsutsugamushi leading to AES. Methodology: A total of 849 cases with clinical diagnosis of AES were enrolled from six districts (Deoria and its adjoining area) of the traditional north Indian Japanese encephalitis (JE) belt. Serum and Cerebrospinal fluid samples were collected and tested for major agent causing acute encephalitis. AES cases either positive for anti-ST IgM antibodies or negative for all tested etiologies were investigated for ST-DNA by real-time PCR. Results: Of these 505 cases, 250 patients were laboratory confirmed for O. tsutsugamushi infection either by anti-ST IgM antibodies positivity (n=206) on serum sample or by ST-DNA detection by real-time PCR assay on CSF sample (n=2) or by both (n=42).Total 29 isolate could be sequenced for 56KDa gene. Conclusion: All the strains were found to cluster with Gilliam strains. The majority of the isolates showed a 97–99% sequence similarity with Thailand and Cambodian strains. Gilliam strain of O.tsusugamushi is an emerging as one of the major aetiologies leading to AES in northern part of India.

Keywords: acute encephalitis syndrome, O. tsutsugamushi, Gilliam strain, North India, cerebrospinal fluid

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1227 Heterologous Expression of a Clostridium thermocellum Proteins and Assembly of Cellulosomes 'in vitro' for Biotechnology Applications

Authors: Jessica Pinheiro Silva, Brenda Rabello De Camargo, Daniel Gusmao De Morais, Eliane Ferreira Noronha

Abstract:

The utilization of lignocellulosic biomass as source of polysaccharides for industrial applications requires an arsenal of enzymes with different mode of action able to hydrolyze its complex and recalcitrant structure. Clostridium thermocellum is gram-positive, thermophilic bacterium producing lignocellulosic hydrolyzing enzymes in the form of multi-enzyme complex, termed celulossomes. This complex has several hydrolytic enzymes attached to a large and enzymically inactive protein known as Cellulosome-integrating protein (CipA), which serves as a scaffolding protein for the complex produced. This attachment occurs through specific interactions between cohesin modules of CipA and dockerin modules in enzymes. The present work aims to construct celulosomes in vitro with the structural protein CipA, a xylanase called Xyn10D and a cellulose called CelJ from C.thermocellum. A mini-scafoldin was constructed from modules derived from CipA containing two cohesion modules. This was cloned and expressed in Escherichia coli. The other two genes were cloned under the control of the alcohol oxidase 1 promoter (AOX1) in the vector pPIC9 and integrated into the genome of the methylotrophic yeast Pichia pastoris GS115. Purification of each protein is being carried out. Further studies regarding enzymatic activity of the cellulosome is going to be evaluated. The cellulosome built in vitro and composed of mini-CipA, CelJ and Xyn10D, can be very interesting for application in industrial processes involving the degradation of plant biomass.

Keywords: cellulosome, CipA, Clostridium thermocellum, cohesin, dockerin, yeast

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1226 Impact of Climate Change on Sea Level Rise along the Coastline of Mumbai City, India

Authors: Chakraborty Sudipta, A. R. Kambekar, Sarma Arnab

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Sea-level rise being one of the most important impacts of anthropogenic induced climate change resulting from global warming and melting of icebergs at Arctic and Antarctic, the investigations done by various researchers both on Indian Coast and elsewhere during the last decade has been reviewed in this paper. The paper aims to ascertain the propensity of consistency of different suggested methods to predict the near-accurate future sea level rise along the coast of Mumbai. Case studies at East Coast, Southern Tip and West and South West coast of India have been reviewed. Coastal Vulnerability Index of several important international places has been compared, which matched with Intergovernmental Panel on Climate Change forecasts. The application of Geographic Information System mapping, use of remote sensing technology, both Multi Spectral Scanner and Thematic Mapping data from Landsat classified through Iterative Self-Organizing Data Analysis Technique for arriving at high, moderate and low Coastal Vulnerability Index at various important coastal cities have been observed. Instead of data driven, hindcast based forecast for Significant Wave Height, additional impact of sea level rise has been suggested. Efficacy and limitations of numerical methods vis-à-vis Artificial Neural Network has been assessed, importance of Root Mean Square error on numerical results is mentioned. Comparing between various computerized methods on forecast results obtained from MIKE 21 has been opined to be more reliable than Delft 3D model.

Keywords: climate change, Coastal Vulnerability Index, global warming, sea level rise

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1225 Understanding Talent Management In French Small And Medium-Sized Enterprises: Towards Multi-Level Modeling

Authors: Abid Kousay

Abstract:

Appeared and developed essentially in large companies and multinationals, Talent Management (TM) in Small and Medium-Sized Enterprises (SMEs) has remained an under-explored subject till today. Although the literature on TM in the Anglo-Saxon context is developing, it remains monopolized in non-European contexts, especially in France. Therefore, this article aims to address these shortcomings through contributing to TM issues by adopting a multilevel approach holding the goal of reaching a global holistic vision of interactions between various levels while applying TM. A qualitative research study carried out within 12 SMEs in France, built on the methodological perspective of grounded theory, will be used in order to go beyond description, to generate or discover a theory or even a unified theoretical explanation. Our theoretical contributions are the results of the grounded theory, the fruit of context considerations and the dynamic of the multilevel approach. We aim firstly to determine the perception of talent and TM in SMEs. Secondly, we formalize TM in SME through the empowerment of all 3 levels in the organization (individual, collective, and organizational). And we generate a multilevel dynamic system model, highlighting the institutionalization dimension in SMEs and the managerial conviction characterized by the domination of the leader’s role. Thirdly, this first study sheds light on the importance of rigorous implementation of TM in SMEs in France by directing CEO and HR and TM managers to focus on elements that upstream TM implementation and influence the system internally. Indeed, our systematic multilevel approach policy reminds them of the importance of strategic alignment while translating TM policy into strategies and practices in SMEs.

Keywords: French context, multilevel approach, talent management, , TM system

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1224 Multi-Stage Classification for Lung Lesion Detection on CT Scan Images Applying Medical Image Processing Technique

Authors: Behnaz Sohani, Sahand Shahalinezhad, Amir Rahmani, Aliyu Aliyu

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Recently, medical imaging and specifically medical image processing is becoming one of the most dynamically developing areas of medical science. It has led to the emergence of new approaches in terms of the prevention, diagnosis, and treatment of various diseases. In the process of diagnosis of lung cancer, medical professionals rely on computed tomography (CT) scans, in which failure to correctly identify masses can lead to incorrect diagnosis or sampling of lung tissue. Identification and demarcation of masses in terms of detecting cancer within lung tissue are critical challenges in diagnosis. In this work, a segmentation system in image processing techniques has been applied for detection purposes. Particularly, the use and validation of a novel lung cancer detection algorithm have been presented through simulation. This has been performed employing CT images based on multilevel thresholding. The proposed technique consists of segmentation, feature extraction, and feature selection and classification. More in detail, the features with useful information are selected after featuring extraction. Eventually, the output image of lung cancer is obtained with 96.3% accuracy and 87.25%. The purpose of feature extraction applying the proposed approach is to transform the raw data into a more usable form for subsequent statistical processing. Future steps will involve employing the current feature extraction method to achieve more accurate resulting images, including further details available to machine vision systems to recognise objects in lung CT scan images.

Keywords: lung cancer detection, image segmentation, lung computed tomography (CT) images, medical image processing

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1223 A Self Beheld the Eyes of the Other: Reflections on Montesquieu's Persian Letters

Authors: Seyed Majid Alavi Shooshtari

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As a multi-layered prose piece of artistry and craftsmanship Charles de Secondat, baron de Montesquieu’s Persian Letters (1721) is a satirical work which records the experiences of two Persian noblemen, Usbek and Rica, traveling through France in the early eighteenth century. Montesquieu creates Persian Letters as a critique of the French society, a critical explanation of what was considered to be 'the Orient' in the period, and an invaluable historical document which illustrates the ways Europe and the East understood each other in the first half of the eighteenth century. However, Persian Letters is considered today, in part, an Orientalist text because of it presenting the culture of the East using stereotypical images. Although, when Montesquieu published Persian Letters, the term Orientalist was a harmless word for people who studied or took an interest in it, the ways in which this Western intellectual author exerts his critique of French social and political life through the eyes of Persian protagonists by placing the example of the Orient (the Other) at the service of an ongoing Eighteen century discourse does raise some Eastern eyebrows. The fact that Persian side of the novel is considered by some critics as a fanciful decor, and the letters sent home are seen as literary props, yet these Eastern men intelligently question the rationality of religious, state, military and cultural practices and uncover much of the absurdity, irrationality or frivolity of European life. By drawing on the insight that Montesquieu’s text problematizes the assumption that orientalism monolithically constructs the Orient as the Other, the present paper aims to examine how the innocent gaze of two Eastern travelers mirrors the ways Europe’s identity defines its-Self.

Keywords: montesquieu, persian letters, ‘the orint’, identity politics, self, the other

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1222 Understanding Retail Benefits Trade-offs of Dynamic Expiration Dates (DED) Associated with Food Waste

Authors: Junzhang Wu, Yifeng Zou, Alessandro Manzardo, Antonio Scipioni

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Dynamic expiration dates (DEDs) play an essential role in reducing food waste in the context of the sustainable cold chain and food system. However, it is unknown for the trades-off in retail benefits when setting an expiration date on fresh food products. This study aims to develop a multi-dimensional decision-making model that integrates DEDs with food waste based on wireless sensor network technology. The model considers the initial quality of fresh food and the change rate of food quality with the storage temperature as cross-independent variables to identify the potential impacts of food waste in retail by applying s DEDs system. The results show that retail benefits from the DEDs system depend on each scenario despite its advanced technology. In the DEDs, the storage temperature of the retail shelf leads to the food waste rate, followed by the change rate of food quality and the initial quality of food products. We found that the DEDs system could reduce food waste when food products are stored at lower temperature areas. Besides, the potential of food savings in an extended replenishment cycle is significantly more advantageous than the fixed expiration dates (FEDs). On the other hand, the information-sharing approach of the DEDs system is relatively limited in improving sustainable assessment performance of food waste in retail and even misleads consumers’ choices. The research provides a comprehensive understanding to support the techno-economic choice of the DEDs associated with food waste in retail.

Keywords: dynamic expiry dates (DEDs), food waste, retail benefits, fixed expiration dates (FEDs)

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1221 Advocating for Those with Limited Mobility

Authors: Dorothy I. Riddle

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Limited mobility (or an inability to walk more than 15 meters without sitting down to rest) restricts full community participation for 13 percent of Canadian adults or 4.2 million persons), yet Canadian accessibility standards are silent on distance to be walked as an accessibility barrier to be addressed. Instead, they focus on ensuring access for the wheeled mobility devices used regularly by le The Accessible Canada Act mandates that Canada be barrier free by 2040, which will necessitate eliminating distance to be walked as a barrier in federal programs and services. This paper details the results of a multi-year research project funded by Accessibility Standards Canada to document the lived experience of those struggling with limited mobility and make recommendations regarding how to ensure accessibility for those with limited mobility. Over 2,600 Canadians from across Canada participated in an online survey and follow-up focus groups. The results underscored the importance of providing not only mobility supports in public facilities but also the information necessary for planning access to federal programs and services. As numerous participants indicated, if they weren’t sure how far they would have to walk, they simply stayed home and depended on friends and relatives for help with errands or appointments. This included failing to participate in civic activities, such as voting, for fear of having to walk too far and stand unsupported for too long. Types of information that were deemed critical included whether or not mobility aids were available, where seating to rest was located throughout the facility, what alternatives to standing while waiting for service and having to walk to the service provider (rather than the provider coming to the customer) were available, and diagrams of accessible parking and its relationship to elevators and services.

Keywords: accessibility standards, distance to be walked, limited mobility, mobility aids, service to customer

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1220 Multi-Modality Imaging of Aggressive Hoof Wall Neoplasia in Two Horses

Authors: Hannah Nagel, Hayley Lang, Albert Sole Guitart, Natasha Lean, Rachel Allavena, Cleide Sprohnie-Barrera, Alex Young

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Aggressive neoplasia of the hoof is a rare occurrence in horses and has been only sporadically described in the literature. In the few cases reported intra-hoof wall, aggressive neoplasia has been documented radiographically and has been described with variable imaging characteristics. These include a well-defined osteolytic area, a smoothly outlined semi-circular defect, an extensive draining tract beneath the hoof wall, as well as an additional large area of osteolysis or an extensive central lytic region. A 20-year-old Quarterhorse gelding and a 10-year-old Thoroughbred gelding were both presented for chronic reoccurring lameness in the left forelimb and left hindlimb, respectively. Both of the cases displayed radiographic lesions that have been previously described but also displayed osteoproliferative expansile regions of additional bone formation. Changes associated with hoof neoplasia are often non-specific due to the nature and capacity of bone to react to pathological insult, which is either to proliferate or be absorbed. Both cases depict and describe imaging findings seen on radiography, contrast radiography, computed tomography, and magnetic resonance imaging before reaching a histological diagnosis of malignant melanoma and squamous cell carcinoma. Although aggressive hoof wall neoplasia is rare, there are some imaging features which may raise our index of suspicion for an aggressive hoof wall lesion. This case report documents two horses with similar imaging findings who underwent multiple assessments, surgical interventions, and imaging modalities with a final diagnosis of malignant neoplasia.

Keywords: horse, hoof, imaging, radiography, neoplasia

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1219 Omni-Modeler: Dynamic Learning for Pedestrian Redetection

Authors: Michael Karnes, Alper Yilmaz

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This paper presents the application of the omni-modeler towards pedestrian redetection. The pedestrian redetection task creates several challenges when applying deep neural networks (DNN) due to the variety of pedestrian appearance with camera position, the variety of environmental conditions, and the specificity required to recognize one pedestrian from another. DNNs require significant training sets and are not easily adapted for changes in class appearances or changes in the set of classes held in its knowledge domain. Pedestrian redetection requires an algorithm that can actively manage its knowledge domain as individuals move in and out of the scene, as well as learn individual appearances from a few frames of a video. The Omni-Modeler is a dynamically learning few-shot visual recognition algorithm developed for tasks with limited training data availability. The Omni-Modeler adapts the knowledge domain of pre-trained deep neural networks to novel concepts with a calculated localized language encoder. The Omni-Modeler knowledge domain is generated by creating a dynamic dictionary of concept definitions, which are directly updatable as new information becomes available. Query images are identified through nearest neighbor comparison to the learned object definitions. The study presented in this paper evaluates its performance in re-identifying individuals as they move through a scene in both single-camera and multi-camera tracking applications. The results demonstrate that the Omni-Modeler shows potential for across-camera view pedestrian redetection and is highly effective for single-camera redetection with a 93% accuracy across 30 individuals using 64 example images for each individual.

Keywords: dynamic learning, few-shot learning, pedestrian redetection, visual recognition

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1218 Characterization of Potato Starch/Guar Gum Composite Film Modified by Ecofriendly Cross-Linkers

Authors: Sujosh Nandi, Proshanta Guha

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Synthetic plastics are preferred for food packaging due to high strength, stretch-ability, good water vapor and gas barrier properties, transparency and low cost. However, environmental pollution generated by these synthetic plastics is a major concern of modern human civilization. Therefore, use of biodegradable polymers as a substitute for synthetic non-biodegradable polymers are encouraged to be used even after considering drawbacks related to mechanical and barrier properties of the films. Starch is considered one of the potential raw material for the biodegradable polymer, encounters poor water barrier property and mechanical properties due to its hydrophilic nature. That apart, recrystallization of starch molecules occurs during aging which decreases flexibility and increases elastic modulus of the film. The recrystallization process can be minimized by blending of other hydrocolloids having similar structural compatibility, into the starch matrix. Therefore, incorporation of guar gum having a similar structural backbone, into the starch matrix can introduce a potential film into the realm of biodegradable polymer. However, hydrophilic nature of both starch and guar gum, water barrier property of the film is low. One of the prospective solution to enhance this could be modification of the potato starch/guar gum (PSGG) composite film using cross-linker. Over the years, several cross-linking agents such as phosphorus oxychloride, sodium trimetaphosphate, etc. have been used to improve water vapor permeability (WVP) of the films. However, these chemical cross-linking agents are toxic, expensive and take longer time to degrade. Therefore, naturally available carboxylic acid (tartaric acid, malonic acid, succinic acid, etc.) had been used as a cross-linker and found that water barrier property enhanced substantially. As per our knowledge, no works have been reported with tartaric acid and succinic acid as a cross-linking agent blended with the PSGG films. Therefore, the objective of the present study was to examine the changes in water vapor barrier property and mechanical properties of the PSGG films after cross-linked with tartaric acid (TA) and succinic acid (SA). The cross-linkers were blended with PSGG film-forming solution at four different concentrations (4, 8, 12 & 16%) and cast on teflon plate at 37°C for 20 h. From the fourier-transform infrared spectroscopy (FTIR) study of the developed films, a band at 1720cm-1 was observed which is attributed to the formation of ester group in the developed films. On the other hand, it was observed that tensile strength (TS) of the cross-linked film decreased compared to non-cross linked films, whereas strain at break increased by several folds. Moreover, the results depicted that tensile strength diminished with increasing the concentration of TA or SA and lowest TS (1.62 MPa) was observed for 16% SA. That apart, maximum strain at break was also observed for TA at 16% and the reason behind this could be a lesser degree of crystallinity of the TA cross-linked films compared to SA. However, water vapor permeability of succinic acid cross-linked film was reduced significantly, but it was enhanced significantly by addition of tartaric acid.

Keywords: cross linking agent, guar gum, organic acids, potato starch

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1217 Hip Resurfacing Makes for Easier Surgery with Better Functional Outcomes at Time of Revision: A Case Controlled Study

Authors: O. O. Onafowokan, K. Anderson, M. R. Norton, R. G. Middleton

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Revision total hip arthroplasty (THA) is known to be a challenging procedure with potential for poor outcomes. Due to its lack of metaphyseal encroachment, hip resurfacing arthroplasty (HRA) is classified as a bone conserving procedure. Although the literature postulates that this is an advantage at time of revision surgery, there is no evidence to either support or refute this claim. We identified 129 hips that had undergone HRA and 129 controls undergoing first revision THA. We recorded the clinical assessment and survivorship of implants in a multi-surgeon, single centre, retrospective case control series for both arms. These were matched for age and sex. Data collected included demographics, indications for surgery, Oxford Hip Score (OHS), length of surgery, length of hospital stay, blood transfusion, implant complexity and further surgical procedures. Significance was taken as p < 0.05. Mean follow up was 7.5 years (1 to 15). There was a significant 6 point difference in postoperative OHS in favour of the revision resurfacing group (p=0.0001). The revision HRA group recorded 48 minutes less length of surgery (p<0.0001), 2 days less in length of hospital stay (p=0.018), a reduced need for blood transfusion (p=0.0001), a need for less complexity in revision implants (p=0.001) and a reduced probability of further surgery being required (P=0.003). Whilst we acknowledge the limitations of this study our results suggest that, in contrast to THA, the bone conservation element of HRA may make for a less traumatic revision procedure with better functional outcomes. Use of HRA has seen a dramatic decline as a result of concerns regarding metallosis. However, this information remains of relevance when counselling young active patients about their arthroplasty options and may become pertinent in the future if the promise of ceramic hip resurfacing is ever realized.

Keywords: hip resurfacing, metallosis, revision surgery, total hip arthroplasty

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1216 Integrating Knowledge Distillation of Multiple Strategies

Authors: Min Jindong, Wang Mingxia

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With the widespread use of artificial intelligence in life, computer vision, especially deep convolutional neural network models, has developed rapidly. With the increase of the complexity of the real visual target detection task and the improvement of the recognition accuracy, the target detection network model is also very large. The huge deep neural network model is not conducive to deployment on edge devices with limited resources, and the timeliness of network model inference is poor. In this paper, knowledge distillation is used to compress the huge and complex deep neural network model, and the knowledge contained in the complex network model is comprehensively transferred to another lightweight network model. Different from traditional knowledge distillation methods, we propose a novel knowledge distillation that incorporates multi-faceted features, called M-KD. In this paper, when training and optimizing the deep neural network model for target detection, the knowledge of the soft target output of the teacher network in knowledge distillation, the relationship between the layers of the teacher network and the feature attention map of the hidden layer of the teacher network are transferred to the student network as all knowledge. in the model. At the same time, we also introduce an intermediate transition layer, that is, an intermediate guidance layer, between the teacher network and the student network to make up for the huge difference between the teacher network and the student network. Finally, this paper adds an exploration module to the traditional knowledge distillation teacher-student network model. The student network model not only inherits the knowledge of the teacher network but also explores some new knowledge and characteristics. Comprehensive experiments in this paper using different distillation parameter configurations across multiple datasets and convolutional neural network models demonstrate that our proposed new network model achieves substantial improvements in speed and accuracy performance.

Keywords: object detection, knowledge distillation, convolutional network, model compression

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1215 Micro-Meso 3D FE Damage Modelling of Woven Carbon Fibre Reinforced Plastic Composite under Quasi-Static Bending

Authors: Aamir Mubashar, Ibrahim Fiaz

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This research presents a three-dimensional finite element modelling strategy to simulate damage in a quasi-static three-point bending analysis of woven twill 2/2 type carbon fibre reinforced plastic (CFRP) composite on a micro-meso level using cohesive zone modelling technique. A meso scale finite element model comprised of a number of plies was developed in the commercial finite element code Abaqus/explicit. The interfaces between the plies were explicitly modelled using cohesive zone elements to allow for debonding by crack initiation and propagation. Load-deflection response of the CRFP within the quasi-static range was obtained and compared with the data existing in the literature. This provided validation of the model at the global scale. The outputs resulting from the global model were then used to develop a simulation model capturing the micro-meso scale material features. The sub-model consisted of a refined mesh representative volume element (RVE) modelled in texgen software, which was later embedded with cohesive elements in the finite element software environment. The results obtained from the developed strategy were successful in predicting the overall load-deflection response and the damage in global and sub-model at the flexure limit of the specimen. Detailed analysis of the effects of the micro-scale features was carried out.

Keywords: woven composites, multi-scale modelling, cohesive zone, finite element model

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1214 The Essence of Culture and Religion in Creating Disaster Resilient Societies through Corporate Social Responsibility

Authors: Repaul Kanji, Rajat Agrawal

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In this era where issues like climate change and disasters are the topics of discussion at national and international forums, it is very often that humanity questions the causative role of corporates in such events. It is beyond any doubt that rapid industrialisation and development has taken a toll in the form of climate change and even disasters, in some case. Thus, demanding to fulfill a corporate's responsibilities in the form of rescue and relief in times of disaster, rehabilitation and even mitigation and preparedness to adapt to the oncoming changes is obvious. But how can the responsibilities of the corporates be channelised to ensure all this, i.e., develop a resilient society? More than that, which factors, when emphasised upon, can lead to the holistic development of the society. To answer this query, an extensive literature review was done to identify several enablers like legislations of a nation, the role of brand and reputation, ease of doing Corporate Social Responsibility, mission and vision of an organisation, religion and culture, etc. as a tool for building disaster resilience. A questionnaire survey, interviews with experts and academicians followed by interpretive structural modelling (ISM) were used to construct a multi-hierarchy model depicting the contextual relationship among the identified enablers. The study revealed that culture and religion are the most powerful driver, which affects other enablers either directly or indirectly. Taking cognisance of the fact that an idea of separation between religion and workplace (business) resides subconsciously within the society, the study tries to interpret the outcome of the ISM through the lenses of past researches (The Integrating Box) and explores how it can be leveraged to build a resilient society.

Keywords: corporate social responsibility, interpretive structural modelling, disaster resilience and risk reduction, the integration box (TIB)

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1213 Fly-Ash/Borosilicate Glass Based Geopolymers: A Mechanical and Microstructural Investigation

Authors: Gianmarco Taveri, Ivo Dlouhy

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Geopolymers are well-suited materials to abate CO2 emission coming from the Portland cement production, and then replace them, in the near future, in building and other applications. The cost of production of geopolymers may be seen the only weakness, but the use of wastes as raw materials could provide a valid solution to this problem, as demonstrated by the successful incorporation of fly-ash, a by-product of thermal power plants, and waste glasses. Recycled glass in waste-derived geopolymers was lately employed as a further silica source. In this work we present, for the first time, the introduction of recycled borosilicate glass (BSG). BSG is actually a waste glass, since it derives from dismantled pharmaceutical vials and cannot be reused in the manufacturing of the original articles. Owing to the specific chemical composition (BSG is an ‘alumino-boro-silicate’), it was conceived to provide the key components of zeolitic networks, such as amorphous silica and alumina, as well as boria (B2O3), which may replace Al2O3 and contribute to the polycondensation process. The solid–state MAS NMR spectroscopy was used to assess the extent of boron oxide incorporation in the structure of geopolymers, and to define the degree of networking. FTIR spectroscopy was utilized to define the degree of polymerization and to detect boron bond vibration into the structure. Mechanical performance was tested by means of 3 point bending (flexural strength), chevron notch test (fracture toughness), compression test (compressive strength), micro-indentation test (Vicker’s hardness). Spectroscopy (SEM and Confocal spectroscopy) was performed on the specimens conducted to failure. FTIR showed a characteristic absorption band attributed to the stretching modes of tetrahedral boron ions, whose tetrahedral configuration is compatible to the reaction product of geopolymerization. 27Al NMR and 29Si NMR spectra were instrumental in understanding the extent of the reaction. 11B NMR spectroscopies evidenced a change of the trigonal boron (BO3) inside the BSG in favor of a quasi-total tetrahedral boron configuration (BO4). Thanks to these results, it was inferred that boron is part of the geopolymeric structure, replacing the Si in the network, similarly to the aluminum, and therefore improving the quality of the microstructure, in favor of a more cross-linked network. As expected, the material gained as much as 25% in compressive strength (45 MPa) compared to the literature, whereas no improvements were detected in flexural strength (~ 5 MPa) and superficial hardness (~ 78 HV). The material also exhibited a low fracture toughness (0.35 MPa*m1/2), with a tangible brittleness. SEM micrographies corroborated this behavior, showing a ragged surface, along with several cracks, due to the high presence of porosity and impurities, acting as preferential points for crack initiation. The 3D pattern of the surface fracture, following the confocal spectroscopy, evidenced an irregular crack propagation, whose proclivity was mainly, but not always, to follow the porosity. Hence, the crack initiation and propagation are largely unpredictable.

Keywords: borosilicate glass, characterization, fly-ash, geopolymerization

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1212 Polymer Nanocoatings With Enhanced Self-Cleaning and Icephobic Properties

Authors: Bartlomiej Przybyszewski, Rafal Kozera, Katarzyna Zolynska, Anna Boczkowska, Daria Pakula

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The build-up and accumulation of dirt, ice, and snow on structural elements and vehicles is an unfavorable phenomenon, leading to economic losses and often also posing a threat to people. This problem occurs wherever the use of polymer coatings has become a standard, among others in photovoltaic farms, aviation, wind energy, and civil engineering. The accumulated pollution on the photovoltaic modules can reduce their efficiency by several percent, and snow stops power production. Accumulated ice on the blades of wind turbines or the wings of airplanes and drones disrupts the airflow by changing their shape, leading to increased drag and reduced efficiency. This results in costly maintenance and repairs. The goal of the work is to reduce or completely eliminate the accumulation of dirt, snow, and ice build-up on polymer coatings by achieving self-cleaning and icephobic properties. It is done by the use of a multi-step surface modification of the polymer nanocoatings. For this purpose, two methods of surface structuring and the preceding volumetric modification of the chemical composition with proprietary organosilicon compounds and/or mineral additives were used. To characterize the surface topography of the modified coatings, light profilometry was utilized. Measurements of the wettability parameters (static contact angle and contact angle hysteresis) on the investigated surfaces allowed to identify their wetting behavior and determine relation between hydrophobic and anti-icing properties. Ice adhesion strength was measured to assess coatings' anti-icing behavior.

Keywords: anti-icing properties, self-cleaning, polymer coatings, icephobic coatings

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1211 Experimental Monitoring of the Parameters of the Ionosphere in the Local Area Using the Results of Multifrequency GNSS-Measurements

Authors: Andrey Kupriyanov

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In recent years, much attention has been paid to the problems of ionospheric disturbances and their influence on the signals of global navigation satellite systems (GNSS) around the world. This is due to the increase in solar activity, the expansion of the scope of GNSS, the emergence of new satellite systems, the introduction of new frequencies and many others. The influence of the Earth's ionosphere on the propagation of radio signals is an important factor in many applied fields of science and technology. The paper considers the application of the method of transionospheric sounding using measurements from signals from Global Navigation Satellite Systems to determine the TEC distribution and scintillations of the ionospheric layers. To calculate these parameters, the International Reference Ionosphere (IRI) model of the ionosphere, refined in the local area, is used. The organization of operational monitoring of ionospheric parameters is analyzed using several NovAtel GPStation6 base stations. It allows performing primary processing of GNSS measurement data, calculating TEC and fixing scintillation moments, modeling the ionosphere using the obtained data, storing data and performing ionospheric correction in measurements. As a result of the study, it was proved that the use of the transionospheric sounding method for reconstructing the altitude distribution of electron concentration in different altitude range and would provide operational information about the ionosphere, which is necessary for solving a number of practical problems in the field of many applications. Also, the use of multi-frequency multisystem GNSS equipment and special software will allow achieving the specified accuracy and volume of measurements.

Keywords: global navigation satellite systems (GNSS), GPstation6, international reference ionosphere (IRI), ionosphere, scintillations, total electron content (TEC)

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1210 Symbiotic Functioning, Photosynthetic Induction and Characterisation of Rhizobia Associated with Groundnut, Jack Bean and Soybean from Eswatini

Authors: Zanele D. Ngwenya, Mustapha Mohammed, Felix D. Dakora

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Legumes are a major source of biological nitrogen, and therefore play a crucial role in maintaining soil productivity in smallholder agriculture in southern Africa. Through their ability to fix atmospheric nitrogen in root nodules, legumes are a better option for sustainable nitrogen supply in cropping systems than chemical fertilisers. For decades, farmers have been highly receptive to the use of rhizobial inoculants as a source of nitrogen due mainly to the availability of elite rhizobial strains at a much lower compared to chemical fertilisers. To improve the efficiency of the legume-rhizobia symbiosis in African soils would require the use of highly effective rhizobia capable of nodulating a wide range of host plants. This study assessed the morphogenetic diversity, photosynthetic functioning and relative symbiotic effectiveness (RSE) of groundnut, jack bean and soybean microsymbionts in Eswatini soils as a first step to identifying superior isolates for inoculant production. According to the manufacturer's instructions, rhizobial isolates were cultured in yeast-mannitol (YM) broth until the late log phase and the bacterial genomic DNA was extracted using GenElute bacterial genomic DNA kit. The extracted DNA was subjected to enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and a dendrogram constructed from the band patterns to assess rhizobial diversity. To assess the N2-fixing efficiency of the authenticated rhizobia, photosynthetic rates (A), stomatal conductance (gs), and transpiration rates (E) were measured at flowering for plants inoculated with the test isolates. The plants were then harvested for nodulation assessment and measurement of plant growth as shoot biomass. The results of ERIC-PCR fingerprinting revealed the presence of high genetic diversity among the microsymbionts nodulating each of the three test legumes, with many of them showing less than 70% ERIC-PCR relatedness. The dendrogram generated from ERIC-PCR profiles grouped the groundnut isolates into 5 major clusters, while the jack bean and soybean isolates were grouped into 6 and 7 major clusters, respectively. Furthermore, the isolates also elicited variable nodule number per plant, nodule dry matter, shoot biomass and photosynthetic rates in their respective host plants under glasshouse conditions. Of the groundnut isolates tested, 38% recorded high relative symbiotic effectiveness (RSE >80), while 55% of the jack bean isolates and 93% of the soybean isolates recorded high RSE (>80) compared to the commercial Bradyrhizobium strains. About 13%, 27% and 83% of the top N₂-fixing groundnut, jack bean and soybean isolates, respectively, elicited much higher relative symbiotic efficiency (RSE) than the commercial strain, suggesting their potential for use in inoculant production after field testing. There was a tendency for both low and high N₂-fixing isolates to group together in the dendrogram from ERIC-PCR profiles, which suggests that RSE can differ significantly among closely related microsymbionts.

Keywords: genetic diversity, relative symbiotic effectiveness, inoculant, N₂-fixing

Procedia PDF Downloads 194