Search results for: surface potential

Authors: S. K. Ghosh, C. Srivastava, P. K. Limaye, V. Kain

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Electroplated hard chromium is widely known in coatings and surface finishing, automobile and aerospace industries because of its excellent hardness, wear resistance and corrosion properties. However, its precursor, Cr+6 is highly carcinogenic in nature and a consensus has been adopted internationally to eradicate this coating technology with an alternative one. The search for alternate coatings to electroplated hard chrome is continuing worldwide. Various alloys and nanocomposites like Co-W alloys, Ni-Graphene, Ni-diamond nanocomposites etc. have already shown promising results in this regard. Basically, in this study, electroless Ni-P alloys with excellent corrosion resistance was taken as the base matrix and incorporation of tungsten as third alloying element was considered to improve the hardness and wear resistance of the resultant alloy coating. The present work is focused on the preparation of Ni–W–P coatings by electrodeposition with different content of phosphorous and its effect on the electrochemical, mechanical and tribological performances. The results were also compared with Ni-W alloys. Composition analysis by EDS showed deposition of Ni-32.85 wt% W-3.84 wt% P (designated as Ni-W-LP) and Ni-18.55 wt% W-8.73 wt% P (designated as Ni-W-HP) alloy coatings from electrolytes containing of 0.006 and 0.01M sodium hypophosphite respectively. Inhibition of tungsten deposition in the presence of phosphorous was noted. SEM investigation showed cauliflower like growth along with few microcracks. The as-deposited Ni-W-P alloy coating was amorphous in nature as confirmed by XRD investigation and step-wise crystallization was noticed upon annealing at higher temperatures. For all the coatings, the nanohardness was found to increase after heat-treatment and typical nanonahardness values obtained for 400°C annealed samples were 18.65±0.20 GPa, 20.03±0.25 GPa, and 19.17±0.25 for alloy coatings Ni-W, Ni-W-LP and Ni-W-HP respectively. Therefore, the nanohardness data show very promising results. Wear and coefficient of friction data were recorded by applying a different normal load in reciprocating motion using a ball on plate geometry. Post experiment, the wear mechanism was established by detail investigation of wear-scar morphology. Potentiodynamic measurements showed coating with a high content of phosphorous was most corrosion resistant in 3.5wt% NaCl solution.

Keywords: corrosion, electrodeposition, nanohardness, Ni-W-P alloy coating

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Authors: Pawasuth Saengdee, Chamras Promptmas, Ting Zeng, Silke Leimkühler, Ulla Wollenberger

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Sulfite has been used as a versatile preservative to limit the microbial growth and to control the taste in some food and beverage. However, it has been reported to cause a wide spectrum of severe adverse reactions. Therefore, it is important to determine the amount of sulfite in food and beverage to ensure consumer safety. An efficient electrocatalytic biosensor for sulfite detection was developed by immobilizing of human sulfite oxidase (hSO) on 3-aminoproplytriethoxysilane (APTES) modified indium tin oxide (ITO) electrode. Cyclic voltammetry was employed to investigate the electrochemical characteristics of the hSO modified ITO electrode for various pretreatment and binding conditions. Amperometry was also utilized to demonstrate the current responses of the sulfite sensor toward sodium sulfite in an aqueous solution at a potential of 0 V (vs. Ag/AgCl 1 M KCl). The proposed sulfite sensor has a linear range between 0.5 to 2 mM with a correlation coefficient 0.972. Then, the additional polymer layer of PVA was introduced to extend the linear range of sulfite sensor and protect the enzyme. The linear range of sulfite sensor with 5% coverage increases from 2.8 to 20 mM at a correlation coefficient of 0.983. In addition, the stability of sulfite sensor with 5% PVA coverage increases until 14 days when kept in 0.5 mM Tris-buffer, pH 7.0 at 4 8C. Therefore, this sensor could be applied for the detection of sulfite in the real sample, especially in food and beverage.

Keywords: sulfite oxidase, bioelectrocatalytsis, indium tin oxide, direct electrochemistry, sulfite sensor

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Authors: Jayanta Pokharel, Gokarna Aryal, Netra Kanaal, Chris Tsokos

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Investment in stocks and shares aims to seek potential gains while weighing the risk of future needs, such as retirement, children's education etc. Analysis of the behavior of the stock market returns and making prediction is important for investors to mitigate risk on investment. Historically, the normal variance models have been used to describe the behavior of stock market returns. However, the returns of the financial assets are actually skewed with higher kurtosis, heavier tails, and a higher center than the normal distribution. The Laplace distribution and its family are natural candidates for modeling stock returns. The Variance-Gamma (VG) distribution is the most sought-after distributions for modeling asset returns and has been extensively discussed in financial literatures. In this paper, it explore the other Laplace family, such as Asymmetric Laplace, Skewed Laplace, Kumaraswamy Laplace (KS) together with Variance-Gamma to model the weekly returns of the S&P 500 Index and it's eleven business sector indices. The method of maximum likelihood is employed to estimate the parameters of the distributions and our empirical inquiry shows that the Kumaraswamy Laplace distribution performs much better for stock returns modeling among the choice of distributions used in this study and in practice, KS can be used as a strong alternative to VG distribution.

Keywords: stock returns, variance-gamma, kumaraswamy laplace, maximum likelihood

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Authors: Rim Ben Amor, Myriam Abidi, Moncef Gueddari

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The purpose of the present study is to assess the level and the distribution of CaO, SO3, Cd, Cu, Pb and Zn incore sediments of Ghannouch-Gabes coast, Gulf of Gabes, Tunisian Mediterranean coast. The XRD analyses indicate that the sediments of Ghannouch-Gabes coast are mainly composed of quartz, calcite, gypsum and fluorine reflecting the impact of the phosphate fertilizer industrial waste. The vertical distribution of surface sediments shows for all the elements analyzed, that the area located between the commercial and the fishing port of Gabes, is the most polluted zone, where the two harbors acted as barriers and limited the dispersion of phosphogypsum discharge. The abundance order of metals was found to be Zn > Cd > Cu >Pb and that the highest levels of heavy metals were found in the uppermost segment of the sediment core compared to lower depth subsurface due to a continuous input of PG release and showed that the area between the two harbor suffered from several types of pollutants compared to reference core C1, collected from non-industrialized area. The level of pollution was evaluated using contamination factor (Cf), pollution load index (PLI) and the geoaccumulation index (Igeo). The obtained results of Igeo allowed us to distinguish that the area between the commercial harbor of Ghannouch and the fishing harbor of Gabes is the most polluted where sediments are strongly contaminated for Pb, Cu and Cd. The pollution load index (PLI) of all sediments collected classified them as "polluted". According to contamination factor (Cf), the sediments can be considered as ‘considerable’ to ‘very high’ contaminated for Pb, ‘very high to moderate’ for Cd, ‘ moderate’ for Zn, between ‘moderate’ and ‘considerable’ for Cu. Statistical analyses show that heavy metals, fluoride, calcium and sulphate are resulting from the same anthropogenic origin. The metallic pollution status of sediments of Ghanouch -Gabes coast is worrying and requires a serious intervention.

Keywords: trace metals, phosphogypsum, core sediments, accumulation factor, contamination factor

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Authors: Ikram Kamal, Mohamed Blaghen

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Petroleum hydrocarbons are serious problems and global pollutants in the environment due to their toxicity, carcinogenicity and persistent organic pollutant properties. One of the approaches to enhance biodegradation of petroleum hydrocarbons is to use biosurfactant. Biosurfactants are amphiphilic biomolecules produced as metabolic by-products from microorganisms they received considerable attention in the field of environmental remediation processes such as bioremediation. Biosurfactants have been considered as a desirable alternative to synthetic surfactants in various applications particularly in the environmental field. In comparison with their synthetic counterparts, biosurfactants have been reported to be less toxic, biodegradable and persistent. In this study we have investigated the potential of bacterial strains collected aseptically from the lagoon Marchika (water and soil) in Nador, Morocco; for the production of biosurfactants. This study also aimed to optimize the biosurfactant production process by changing the variables that influence the type and amount of biosurfactant produced by these microorganisms such as: carbon sources and also other physical and chemical parameters such as temperature and pH. Emulsification index, methylene blue test and thin layer chromatography (TLC) revealed the ability of strains used in this study to produce compounds that could emulsify gasoline. In addition, a HPLC/MS was used to separate and identify different biosurfactants purified.

Keywords: petroleum hydrocarbons, biosurfactants, biodegradation, lagoon marchika, emulsification index

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Authors: Mohammad Karimizadehardakani, Hooman Minoonejad, Reza Rajabi, Ali Sharifnejad

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Background: Ankle sprain is one of the most important risk factor of anterior cruciate ligament (ACL) injury. Also, functional ankle instability (FAI) population has alterations in lower extremity sagittal plane biomechanics during landing task. We want to examine whether biomechanical alterations demonstrated by FAI patients are associated with the mechanism of ACL injury during high risk and sport related tasks. Methods: Sixteen basketball player with FAI and 16 non-injured control performed a single-leg cross drop landing. Knee sagittal and frontal (ATSF) was calculated. Independent t-tests, multiple linear regression, and Pearson correlation were used for analysis data. Result: Subject with FAI showed more peak ATFS, posterior ground reaction force (GRF) and less knee flexion, compared to the controls (P= 0.001, P= 0.004, P= 0.011). Knee flexion (r= −0.824, P = 0.011) and posterior GRF (r= 0.901, P = .001) were correlated with ATSF; Posterior GRF was factor that most explained the variance in ATSF (R2= 0.645; P = .001) in the FAI group. Conclusions: Result of our study showed there is a potential biomechanical relationship between the presence of FAI and risk factors associated with ACL injury mechanism.

Keywords: functional ankle instability, anterior cruciate ligament, biomechanics, risk factor

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Authors: Ahmed A. Lugard, Mohammed A. Aliyu

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This paper studied the influence of urban development and its accompanied land surface transformation on sediment concentration of a natural flowing Ginzo river across the city of Katsina. An opposite twin river known as Tille river, which is less urbanized, was used to compare the result of the sediment concentration of the Ginzo River in order to ascertain the consequences of the urban area on impacting the sediment concentration. An instrument called USP 61 point integrating cable way sampler described by Gregory and walling (1973), was used to collect the suspended sediment samples in the wet season months of June, July, August and September. The result obtained in the study shows that only the sample collected at the peripheral site of the city, which is mostly farmland areas resembles the results in the four sites of Tille river, which is the reference stream in the study. It was found to be only + 10% different from one another, while at the other three sites of the Ginzo which are highly urbanized the disparity ranges from 35-45% less than what are obtained at the four sites of Tille River. In the generalized assessment, the t-distribution result applied to the two set of data shows that there is a significant difference between the sediment concentration of urbanized River Ginzo and that of less urbanized River Tille. The study further discovered that the less sediment concentration found in urbanized River Ginzo is attributed to concretization of surfaced, tarred roads, concretized channeling of segments of the river including the river bed and reserved open grassland areas, all within the catchments. The study therefore concludes that urbanization affect not only the hydrology of an urbanized river basin, but also the sediment concentration which is a significant aspect of its geomorphology. This world certainly affects the flood plain of the basin at a certain point which might be a suitable land for cultivation. It is recommended here that further studies on the impact of urbanization on River Basins should focus on all elements of geomorphology as it has been on hydrology. This would make the work rather complete as the two disciplines are inseparable from each other. The authorities concern should also trigger a more proper environmental and land use management policies to arrest the menace of land degradation and related episodic events.

Keywords: environment, infiltration, river, urbanization

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Authors: Karissa A. Graham

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Pyoderma gangrenosum (PG) is a prototypic autoinflammatory neutrophilic dermatosis that is a rare disorder. It presents a diagnostic challenge owing to its variable presentation, clinical overlap with other conditions, it is often associated with other systemic conditions, and there is no definitive histological or laboratory characteristic. The Delphai consensus for PG includes the presence of at least one ulcer on the anterior lower limb. Systemic corticosteroids and immunosuppressive therapies are the mainstay treatment for PG. We describe a case report of delayed diagnosis of ulcerative pyoderma gangrenosum in a 44-year-old male on his forearm. The patient presented with an infected ulcer on his right forearm that had been present for over three years. The patient was a Type 2 Diabetic with no personal or family history of inflammatory bowel disease or other autoimmune diseases. The patient was initially investigated for malignancy, but biopsies returned as chronic inflammatory tissue with neutrophilic infiltrate and no malignancy. The patient was commenced on systemic prednisone for the treatment of pyoderma gangrenosum. The diagnosis of ulcerative PG poses a challenge given the vast differential diagnosis for a cutaneous ulcer (i.e., malignant, vascular, autoimmune, trauma, infective, etc.). Diagnostic accuracy is important given that the treatment for PG with steroids does not go without risks and indeed may be contraindicated in other potential causes of the ulcer. Indeed, more common and more sinister causes of ulcers should be investigated first, as death from PG is quite rare.

Keywords: dermatological diagnosis, dermatosis, pyoderma gangrenosum, rare presentation

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Authors: Shan Li, Qiuwen Ma

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Integrated project delivery (IPD) is a project delivery method distinguished by a shared risk/rewards mechanism and multiparty agreement. IPD has drawn increasing attention from construction industry due to its reliability to deliver high-performing buildings. However, unavailable IPD specific insurance concerns the industry participants who are interested in IPD implementation. Even though the risk management capability can be enhanced using shared risk mechanism, some risks may occur when the partners do not commit themselves into the integrated practices in a desired manner. This is because the intense collaboration and close integration can not only create added value but bring new opportunistic behaviors and disputes. The study is aimed to investigate the risks of implementing IPD using Bayesian theory. IPD risk taxonomy is presented to identify all potential risks of implementing IPD and a risk network map is developed to capture the interdependencies between IPD risks. The conditional relations between risk occurrences and the impacts of IPD risks on project performances are evaluated and simulated based on Bayesian theory. The probability of project outcomes is predicted by simulation. In addition, it is found that some risks caused by integration are most possible occurred risks. This study can help the IPD project participants identify critical risks of adopting IPD to improve project performances. In addition, it is helpful to develop IPD specific insurance when the pertinent risks can be identified.

Keywords: Bayesian theory, integrated project delivery, project risks, project performances

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Authors: Omar M. Al Aufi, Abdulwahab Noorwali, Ahmed Al Abd, Safia Alattas, Fathya Zahran, Fahd Almutairi

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Cisplatin (CDDP) is a potent anticancer agent used for several tumor types. Thymoquinone (TQ) is a naturally occurring compound drawing great attention as an anticancer and chemomodulator for chemotherapies. Herein, we studied the potential cytotoxicity of thymoquinone, CDDP and their combination against human oral squamous cell carcinoma cells in contrast to normal oral epithelial cells. CDDP similarly killed both head and neck squamous cell carcinoma cells (UMSCC-14C) and normal oral epithelial cells (OEC). TQ alone exerted considerable cytotoxicity against UMSCC-14C cells, while it induced a weaker killing effect against normal oral epithelial cells (OEC). The equitoxic combination of TQ and CDDP showed additive to synergistic interaction against both UMSCC-14C and OEC cells. TQ alone increased apoptotic cell fraction in UMSCC-14C cells as early as after 6 hours. In addition, prolonged exposure of UMSCC-14C to TQ alone resulted in 96.7±1.6% total apoptosis, which was increased after combination with CDDP to 99.3±1.2% in UMSCC-14C cells. On the other hand, TQ induced a marginal increase in the apoptosis in OEC and even decreased the apoptosis induced by CDDP alone. Finally, apoptosis induction results were confirmed by the change in the expression levels of p53, Bcl-2 and Caspase-9 proteins in both UMSCC-14c and OEC cells.

Keywords: thymoquinone, cisplatin, apoptosis, oral squamous cell carcinoma, P53, Caspase-9, Bcl-2

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Authors: Refal Hussain, Saifuddin M. Nomanbhay

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Glycerol is a valuable raw material for the production of industrially useful metabolites. Among many promising applications for the use of glycerol is its bioconversion to high value-added compounds, such as bioethanol through microbial fermentation. Bioethanol is an important industrial chemical with emerging potential as a biofuel to replace vanishing fossil fuels. The yield of liquid fuel in this process was greatly influenced by various parameters viz, temperature, pH, glycerol concentration, organic concentration, and agitation speed were considered. The present study was undertaken to investigate optimum parameters for bioethanol production from raw glycerol by immobilized mutant Escherichia coli (E.coli) (ATCC11505) strain on chitosan cross linked glutaraldehyde optimized by Taguchi statistical method in shake flasks. The initial parameters were set each at four levels and the orthogonal array layout of L16 (45) conducted. The important controlling parameters for optimized the operational fermentation was temperature 38 °C, medium pH 6.5, initial glycerol concentration (250 g/l), and organic source concentration (5 g/l). Fermentation with optimized parameters was carried out in a custom fabricated shake flask. The predicted value of bioethanol production under optimized conditions was (118.13 g/l). Immobilized cells are mainly used for economic benefits of continuous production or repeated use in continuous as well as in batch mode.

Keywords: bioethanol, Escherichia coli, immobilization, optimization

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Authors: Chikwelu Edward Emenike, Ogbuagu Uchenna Fredrick

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About 34% of the solar radiant energy reaching the earth is immediately reflected back to space as incoming radiation by clouds, chemicals, dust in the atmosphere and by the earth’s surface. Most of the remaining 66% warms the atmosphere and land. Most of the incoming solar radiation not reflect away is degraded into low-quality heat and flows into space. The rate at which this energy returns to space as low-quality heat is affected by the presence of molecules of greenhouse gases. Gaseous emission was measured with the aid of Growen gas Analyzer with a digital readout. Total measurements of eight parameters of twelve selected sample locations taken at two different seasons within two months were made. The ambient air quality investigation in Anambra State has shown the overall mean concentrations of gaseous emission at twelve (12) locations. The mean gaseous emissions showed (NO2=0.66ppm, SO2=0.30ppm, CO=43.93ppm, H2S=2.17ppm, CH4=1.27ppm, CFC=1.59ppb, CO2=316.33ppm, N2O=302.67ppb and O3=0.37ppm). These values do not conform to the National Ambient Air Quality Standard (NAAQS) and thus contribute significantly to the global warming. Because some of these gaseous emissions (SO2, NO2) are oxidizing agents, they act as irritants that damage delicate tissues in the eyes and respiratory passages. These can impair lung function and trigger cardiovascular problems as the heart tries to compensate for lack of Oxygen by pumping faster and harder. The major sources of air pollution are transportation, industrial processes, stationary fuel combustion and solid waste disposal, thus much is yet to be done in a developing country like Nigeria. Air pollution control using pollution-control equipment to reduce the major conventional pollutants, relocating people who live very close to dumpsites, processing and treatment of gases to produce electricity, heat, fuel and various chemical components should be encouraged.

Keywords: ambient air, atmosphere, greenhouse gases, anambra state

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Authors: Hitendra Raj Joshi, Bipin Lamichhane

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Groundwater is the main source of water for the industries of Balaju Industrial District (BID) and the denizens of Balaju-Boratar area. The quantity of groundwater is in a fatal condition in the area than earlier days. Water levels in shallow wells have highly lowered and deep wells are not providing an adequate amount of water as before because of higher extraction rate than the recharge rate. The main recharge zone of the shallow aquifer lies at the foot of Nagarjuna mountain, where recent colluvial debris are accumulated. Urbanization in the area is the main reason for decreasing water table. Recharge source for the deep aquifer in the region is aquiclude leakage. Sand layer above the Kalimati clay is the shallow aquifer zone, which is limited only in Balaju and eastern part of the Boratar, while the layer below the Kalimati clay spreading around Gongabu, Machhapohari, and Balaju area is considered as a potential area of deep aquifer. Over extraction of groundwater without considering water balance in the aquifers may dry out the source and can initiate the land subsidence problem. Hence, all the responsible of the industries in BID area and the denizens of Balaju-Boratar area should be encouraged to practice artificial groundwater recharge.

Keywords: aquiclude leakage, Kalimati clay, groundwater recharge

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Authors: Patrascu Andrei Tudor

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One of the main problems in high energy physics is the fact that we do not have a complete understanding of the interaction between local and global effects in gauge theory. This has an increasing impact on our ability to access the non-perturbative regime of most of our theories. Our theories, while being based on gauge groups considered to be simple or semi-simple and connected, are expected to be described by their simple local linear approximation, namely the Lie algebras. However, higher homotopy properties resulting in gauge anomalies appear frequently in theories of physical interest. Our assumption that the groups we deal with are simple and simply connected is probably not suitable, and ways to go beyond such assumptions, particularly in gauge theories, where the Lie algebra linear approximation is prevalent, are not known. We approach this problem from two directions: on one side we are explaining the potential role of formal group laws in describing certain higher homotopical properties and interferences with local or perturbative effects, and on the other side, we employ a categorical approach leading to synthetic theory and a way of looking at gauge theories. The topos approach is based on a geometry where the fundamental logic is intuitionistic logic, and hence the ‘tertium non datur’ principle is abandoned. This has a remarkable impact on understanding conformal symmetry and its anomalies in string theory in various dimensions.

Keywords: Gauge theory, formal group laws, Topos theory, conformal symmetry

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Authors: Shuofeng Yuan, Bojian Zheng

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Assembly of the heterotrimeric polymerase complex of influenza virus from the individual subunits PB1, PA, and PB2 is a prerequisite for viral replication, in which the interaction between the N-terminal of PB1 (PB1N) and the C terminal of PA (PAC) may be a desired target for antiviral development. In this study, we first compared the feasibility of high throughput screening by enzyme-linked immunosorbent assay (ELISA) and fluorescence polarization (FP) assay. Among the two, ELISA was demonstrated to own broader dynamic range so that it was used for screening inhibitors, which blocked PA and PB1 interaction. Several binding inhibitors of PAC-PB1N were identified and subsequently tested for the antiviral efficacy. Apparently, 3-(2-chlorophenyl)-6-ethyl-7-methyl[1,2,4]triazolo[4,3-a]pyrimidin-5-ol, designated ANA-1, was found to be a strong inhibitor of PAC-PB1N interaction and act as a potent antiviral agent against the infections of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9 and H9N2 subtypes, in cell cultures. Intranasal administration of ANA-1 protected mice from lethal challenge and reduced lung viral loads in H1N1 virus infected BALB/c mice. Docking analyses predicted that ANA-1 bound to an allosteric site of PAC, which would cause conformational changes thereby disrupting the PAC-PB1N interaction. Overall, our study has identified a novel compound with potential to be developed as an anti-influenza drug.

Keywords: influenza, antiviral, viral polymerase, compounds

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Authors: Priyanka Jain, Meera Srivastava

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Among important insect pests of stored grains, the pulse beetle Callosobruchus chinensis Linn. (Coleoptera: Bruchidae) is one such pest causing considerable damage to stored pulses. An effort was made to screen plant Tephrosia purpurea (Family: Fabaceae) for its efficacy against the said pest. The pulse beetle C. chinensis was raised on green gram Vigna radiata in incubators maintained at 28 ± 2°C and 70% RH. Different formulations using plant parts (root, stem, leaf and fruit) were employed in the form of aqueous suspension, aqueous extract and ether extract and the treatments were made using different dose concentrations, namely 1%, 2.5%, 5% and 10%, besides normal and control. Specific number of adult insects were released in muslin cloth covered beakers containing weighed green gram grains and treated with different dose concentrations (w/v). Observations for the number of eggs laid by the pest insect C. chinensis was recorded after three days of treatment and it was observed that in general all the treatments of the plant resulted in significant decrease in the eggs laid (no/pair) by the insect, suggesting that the selected plant has a potential to be used against C. chinensis.

Keywords: Callosobruchus chinensis, egg laying, Tephrosia purpurea, Fabaceae, plant formulations

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Authors: Adhara Puspa Noorita, Azkiyatin Nailil M., Rita Aryanti, Sushanti Nuraini, Pujiati Abbas, Suparmi

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T-Dabuto is a tea made from leaves and fruits of parijoto (Madinella speciosa L.), which flavonoid, saponin and tanin contained in that tea are reported have diarrhea-caused antibacterial activity. However, the in vivo antidiarrhea effect have not clear yet. This study was conducted to determine the effect of T-DABUTO to faecal characteristics in male Balb/C-mice induced oleum ricini. Experimental research with post-test only control group design was conducted using 35 young male mice strain Balb-C which was divided into 5 groups. All groups were induced by 0.7 ml/ head of oleum ricini and 3 hours later followed by aquadest for first group, while the 2nd, 3rd, 4th and 5th group were treated by T-DABUTO solution with 75 mg/kgBW, 150 mg/kgBW, 300 mg/kgBW, and 600 mg/kgBW respectively as 0.7 ml/ head/ 0.5 hous for 8 hours. Feces collected were used to identify the frequency, absorbtion diameter and fecal weight. T-DABUTO on dose 75 mg/kg BW has the highest antidiarrhea activity which the mean of frequency defecation, water feacal absorbsion and feacal weight were 1.71±0.95 times, 0.38±0.49 mm, 0.43±0.28 mg, respectively. The T-DABUTO treatment did not influence the body weight of diarrheal mice. The T-DABUTO is potential as one of natural diarrhea tratment, especially in children.

Keywords: diarrhea, flavonid, tannin, saponin

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Authors: Ogunnaiya Racheal Taiwo

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Children's formative years are crucial to their growth; it is, therefore, necessary for all the stakeholders to ensure that the pupils have an enabling quality of life which is essential for realizing their potential. For children to live and grow, they need a secure home, nutritious food, good health care, and quality education. This paper, therefore, investigates the implications of a depressed economy on the classroom learning of Nigerian children as it is clear that Nigeria is currently experiencing the worst economic depression in several decades, which affects a substantial proportion of children. The study is qualitative research, and it adopts a phenomenological approach where the experiences of respondents are examined qualitatively. Three senatorial districts in Oyo State were considered, and 50 teachers, both male, and female were chosen from each senatorial district for an interview through conversational key informants' interviews. The interviewees were recorded, transcribed, and presented using thematic analysis. Findings showed that more children have dropped out since the beginning of the year than in previous years. It was also recorded that learning has become challenging as children now find it harder to acquire learning materials. It was recommended that the government should reimburse early childhood schools to lessen the effect of the inability to purchase materials and pay school fees. It was also recommended that an intervention be made to approach and resolve issues associated with out-of-school children.

Keywords: childhood, classroom, education, depressed economy, poverty

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Authors: Burcu Doymus, Fatma N. Kok, Sakip Onder

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Titanium and titanium-based materials are commonly used to replace or regenerate the injured or lost tissues because of accidents or illnesses. Hospital infections and strong bond formation at the implant-tissue interface are directly affecting the success of the implantation as weak bonding with the native tissue and hospital infections lead to revision surgery. The purpose of the presented study is to modify the surface of the titanium substrates with nano/microspheres for local drug delivery and to prevent hospital infections. Firstly, titanium surfaces were silanized with APTES (3-Triethoxysilylpropylamine) following the negatively charged oxide layer formation. Then characterization studies using Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were done on the modified surfaces. Secondly, microspheres/nanospheres were prepared with chitosan that is a natural polymer and having valuable properties such as non-toxicity, high biocompatibility, low allergen city and biodegradability for biomedical applications. Antibiotic (ciprofloxacin) loaded micro/nanospheres have been fabricated using emulsion cross-linking method and have been immobilized onto the titanium surfaces with different immobilization techniques such as covalent bond and entrapment. Optimization studies on size and drug loading capacities of micro/nanospheres were conducted before the immobilization process. Light microscopy and SEM were used to visualize and measure the size of the produced micro/nanospheres. Loaded and released drug amounts were determined by using UV- spectrophotometer at 278 nm. Finally, SEM analysis and drug release studies on the micro/nanospheres coated Ti surfaces were done. As a conclusion, it was shown that micro/nanospheres were immobilized onto the surfaces successfully and drug release from these surfaces was in a controlled manner. Moreover, the density of the micro/nanospheres after the drug release studies was higher on the surfaces where the entrapment technique was used for immobilization. Acknowledgement: This work is financially supported by The Scientific and Technological Research Council Of Turkey (Project # 217M220)

Keywords: chitosan, controlled drug release, nanosphere, nosocomial infections, titanium

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Authors: Michał Witas

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This paper presents a technical approach to analysis of security of SCADA systems. Main goal of the paper is to make SCADA administrators aware of risks resulting from SCADA systems usage and to familiarize with methods that can be adopt to existing or planned system, to increase overall system security level. Because SCADA based systems become a industrial standard, more attention should be paid to the security of that systems. Industrial Control Systems (ICS) like SCADA are responsible for controlling crucial aspects of wide range of industrial processes. In pair with that responsibility, goes a lot of money that can be earned or lost – this fact is main reason of increased interest of attackers. Additionally ICS are often responsible for maintaining resources strategic from the point of view of national economy, like electricity (including nuclear power plants), heating, water resources or military facilities, so they can be targets of terrorist cybernetic attacks. Without proper risk analysis and management, vulnerabilities resulting from the usage of SCADA can be easily exploited by potential attacker. Paper is based mostly on own experience in systems security, gathered during academic studies and professional work in international company. As title suggests, it will cover only basics of topic, because every of points mentioned in the document can be base for additional research and papers.

Keywords: denial of service, SCADA, security policy, distributed network

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Authors: Fatemeh Soltani, Simindokht Shirvani Arani, Ali Bahrami Samani, Mahdi Sadeghi, Kamal Yavari

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Cerium-141 [T1/2 = 32.501 days, Eβ (max) = 0.580 (29.8%) and 0.435(70.2%) MeV, Eγ=145.44 (48.2%) keV] possesses radionuclidic properties suitable for use in palliative therapy of bone metastases. 141Ce also has gamma energy of 145.44 keV, which resembles that of 99mTc. Therefore, the energy window is adjustable on the Tc-99m energy because of imaging studies. 141Ce can be produced through a relatively easy route that involves thermal neutron bombardment on natural CeO2 in medium flux research reactors (4–5×1013 neutrons/cm2•s). The requirement for an enriched target does not arise. Ethylenediamine tetramethylene phosphonic acid (EDTMP) was synthesized and radiolabeled with 141Ce. Complexation parameters were optimized to achieve maximum yields (>99%). The radiochemical purity of 141Ce-EDTMP was evaluated by radio-thin layer chromatography. The stability of the prepared formulation was monitored for one week at room temperature, and results showed that the preparation was stable during this period (>99%). Biodistribution studies of the complexes carried out in wild-type rats exhibited significant bone uptake with rapid clearance from blood. The properties of produced 141Ce-EDTMP suggest applying a new efficient bone pain palliative therapeutic agent to overcome metastatic bone pains.

Keywords: bone pain palliative, cerium-141, EDTMP, radiopharmaceutical

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Authors: N. P. G. N. Chandrasekara, R. M. Pashley

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Ion exchange (IEX) resins are commonly available as cationic or anionic resins but not as polyampholytic resins. This is probably because sequential acid and base washing cannot produce complete regeneration of polyampholytic resins with chemically attached anionic and cationic groups in close proximity. The ‘Sirotherm’ process, developed by the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Melbourne, Australia was originally based on the use of a physical mixture of weakly basic (WB) and weakly acidic (WA) ion-exchange resin beads. These resins were regenerated thermally and they were capable of removing salts from an aqueous solution at higher temperatures compared to the salt sorbed at ambient temperatures with a significant reduction of the sorption capacity with increasing temperature. A new process for the efficient regeneration of mixed bead resins using ammonium bicarbonate with heat was studied recently and this chemical/thermal regeneration technique has the capability for completely regenerating polyampholytic resins. Even so, the low IEX capacities of polyampholytic resins restrict their commercial applications. Recently, we have established another novel process for increasing the IEX capacity of a typical polyampholytic resin. In this paper we will discuss the chemical/thermal regeneration of a polyampholytic (WA/WB) resin and a novel process for enhancing its ion exchange capacity, by increasing its internal pore area. We also show how effective this method is for completely recycled regeneration, with the potential of substantially reducing chemical waste.

Keywords: capacity, ion exchange, polyampholytic resin, regeneration

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Authors: Ayoub Azizi-Shotorkhoft, Tahereh Mohammadabadi, Hosein Motamedi, Morteza Chaji, Hasan Fazaeli

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This study was conducted to investigate nutritive value of wheat straw processed with termite gut symbiotic bacteria with lignocellulosic-degrading potential including Bacillus licheniformis, Ochrobactrum intermedium and Microbacterium paludicola in vitro. These bacteria were isolated by culturing termite guts contents in different culture media containing different lignin and lignocellulosic materials that had been prepared from water-extracted sawdust and wheat straw. Results showed that incubating wheat straw with all of three isolated bacteria increased (P<0.05) acid-precipitable polymeric lignin (APPL) compared to control, and highest amount of APPL observed following treatment with B. licheniformis. Highest and lowest (P<0.05) in vitro gas production and ruminal organic matter digestibility were obtained when treating wheat straw with B. licheniformis and control, respectively. However, other fermentation parameters such as b (i.e., gas production from the insoluble fermentable fractions at 144h), c (i.e., rate of gas production during incubation), ruminal dry matter digestibility, metabolizable energy, partitioning factor, pH and ammonia nitrogen concentration were similar between experimental treatments (P>0.05). It is concluded that processing wheat straw with isolated bacteria improved its nutritive value as ruminants feed.

Keywords: termite gut bacteria, wheat straw, nutritive value, ruminant

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Authors: Betina Luiza Koop, Lenilton Santos Soares, Karina Cesca, Germán Ayala Valencia, Alcilene Rodrigues Monteiro

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Active and smart food packaging has been studied to control and extend the food shelf-life. However, active compounds such as anthocyanins (ACNs) are unstable to high temperature, light, and pH changes. Several alternatives to stabilize and protect the anthocyanins have been researched, such as adsorption on nanoclays. Thus, this work aimed to stabilize anthocyanin extracted from jambolan fruit (Syzygium cumini), a noncommercial fruit, to development of food package sensors. The anthocyanin extract from jambolan pulp was concentrated by ultrafiltration and adsorbed on montmorillonite. The final biohybrid material was characterized by pH and color. Anthocyanins were adsorbed on nanoclay at pH 1.5, 2.5, and 3.5 and temperatures of 10 and 20 °C. The highest adsorption values were obtained at low pH at high temperatures. The color and antioxidant activity of the biohybrid was maintained for 60 days. A test of the color stability at pH from 1 to 13, simulating spoiled food using ammonia vapor, was performed. At pH from 1 to 5, the ACNs pink color was maintained, indicating that the flavylium cation form was preserved. At pH 13, the biohybrid presented yellow color due to the ACN oxidation. These results showed that the biohybrid material developed has potential application as a sensor to indicate the freshness of meat products.

Keywords: anthocyanin, biohybrid, food, smart packaging

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Authors: Shaherah Jordan, Paula Vandergert

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The discussion on public charging infrastructure is usually framed around the ‘chicken-egg’ challenge of consumers feeling reluctant to purchase without the necessary infrastructure and policymakers reluctant to invest in the infrastructure without the demand. However, public charging infrastructure may be more crucial to electric vehicle (EV) adoption than previously thought. Historically, access to residential charging was thought to be a major factor in potential for growth in the EV market as it offered a guaranteed place for a vehicle to be charged. The purpose of this study is to understand how the built environment may encourage uptake of EVs by seeking a correlation between EV ownership and public charging points in an urban and densely populated city such as London. Using a statistical approach with data from the Department for Transport and Zap-Map, a statistically significant correlation was found between the total (slow, fast and rapid) number of public charging points and a number of EV registrations per borough – with the strongest correlation found between EV registrations and rapid chargers. This research does not explicitly prove that there is a cause and effect relationship between public charging points EVs but challenges some of the previous literature which indicates that public charging infrastructure is not as important as home charging. Furthermore, the study provides strong evidence that public charging points play a functional and psychological role in the adoption of EVs and supports the notion that the built environment can influence human behaviour.

Keywords: behaviour change, electric vehicles, public charging infrastructure, transportation

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Authors: Mohammad J. Khattak, Atif Khan, Thomas C. Pesacreta

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Millions of tons of sugarcane bagasse ash (SBA) are produced as a byproduct by burning sugarcane bagasse in powerplants to run the steam engines for sugar production. This bagasse ash is disposed into landfills effecting their overall capacity. SBA contains very fine particles that can easily become airborne, causing serious respiratory health risks when inhaled. This research study evaluated the utilization of high dosage of SBA for developing geopolymer based “Green” construction materials. An experimental design matrix was developed with varying dosages of SBA (0, 20%, 60%, and 80%) and Na₂SiO3/NaOH ratio (0, 0.5, 1, 1.5, 2) based on the response surface methodology. Precursor (consisting of SBA and fly ash) to aggregate ration was kept constant at 30:70 and the alkali to binder ratio was maintained at 0.45 for all the mixtures. Geopolymer samples of size 50.8 x 50.8 mm (2” X 2”) were casted and cured at 65oC for 48 hours in a water bath followed by curing at room temperature for 24 hours. The samples were then tested for compressive strength as per ASTM C39. The results revealed that based on varying SBA dosage the compressive strengths ranged from 6.78 MPa to 22.63 MPa. Moreover, the effect of SiO2, Na₂O and Fe₂O₃ on the compressive strength of these mixtures was also evaluated. The results depicted that the compressive strength increased with increasing Na₂O and Fe₂O₃ concentration in the binder. It was also observed that the compressive strength of SBA based geopolymer mixtures improved as the SiO₂ content increased, reaching an optimum at 42%. However, further increase in SiO₂ reduced the strength of the mixtures. The resulting geopolymer mixtures possess compressive strengths according to the requirements set by ASTM standard. Such mixtures can be used as a structural and non-structural element as strong road bases, sidewalks, curbs, bricks for buildings and highway infrastructure. Using industrial SBA in geopolymer based construction materials can address the carbon emissions related to cement production, reduce landfill burden from SBA storage, and mitigate health risks associated with high content of silica in SBA.

Keywords: compressive strength, geopolymer concrete, green materials, sugarcane bagasse ash

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Authors: Amin Kamal Akhnoukh, Lois Zaki Kamel, Magued Mourad Barsoum

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The objective of this research is to mitigate and prevent the alkali silica reactivity (ASR) in highway construction projects. ASR is a deleterious reaction initiated when the silica content of the aggregate reacts with alkali hydroxides in cement in the presence of relatively high moisture content. The ASR results in the formation of an expansive white colored gel-like material which forms the destructive tensile stresses inside hardened concrete. In this research, different types of local aggregates available in the State of Arkansas were mixed and mortar bars were poured according to the ASTM specifications. Mortar bars expansion was measured versus time and aggregates with potential ASR problems were detected. Different types of supplementary cementitious materials (SCMs) were used in remixing mortar bars with highly reactive aggregates. Length changes for remixed bars proved that different types of SCMs can be successfully used in reducing the expansive effect of ASR. SCMs percentage by weight is highly dependent on the SCM type. The result of this study will help avoiding future losses due to ASR cracking in construction project and reduce the maintenance, repair, and replacement budgets required for highways network.

Keywords: alkali silica reaction, aggregates, misture, cracks, Mortar Bar Test, supplementary cementitious materials

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Authors: Michael Aupetit, Mahmoud Al-ismail, Khaled Mohamed

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Cancer is a major public health problem all over the world. Breast cancer has the highest incidence rate over all cancers for women in Qatar making its study a top priority of the country. Human cancer is a dynamic disease that develops over an extended period through the accumulation of a series of genetic alterations. A Darwinian process drives the tumor cells toward higher malignancy growing the branches of a progression tree in the space of genes expression. Although it is not possible to track these genetic alterations dynamically for one patient, it is possible to reconstruct the progression tree from the aggregation of thousands of tumor cells’ genetic profiles from thousands of different patients at different stages of the disease. Analyzing the progression tree is a way to detect pivotal molecular events that drive the malignant evolution and to provide a guide for the development of cancer diagnostics, prognostics and targeted therapeutics. In this work we present the development of a Visual Analytic web platform CanVis enabling users to upload gene-expression data and analyze their progression tree. The server computes the progression tree based on state-of-the-art techniques and allows an interactive visual exploration of this tree and the gene-expression data along its branching structure helping to discover potential driver genes.

Keywords: breast cancer, progression tree, visual analytics, web platform

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Authors: Rakesh Bhatia

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Students often face significant challenges in understanding and applying trigonometric identities, primarily due to the overwhelming need to memorize numerous formulas. This often leads to confusion, frustration, and difficulty in effectively using these formulas across diverse types of problems. Traditional methods of learning trigonometry demand considerable time and effort, which can further hinder comprehension and application. Vedic Mathematics offers an innovative and simplified approach to overcoming these challenges. This paper explores how Baudhayan Numbers, can be used to derive trigonometric identities and simplify calculations related to height and distance. Unlike conventional approaches, this method minimizes the need for extensive paper-based calculations, promoting a conceptual understanding. Using Vedic Mathematics Sutras such as Anurupyena and Vilokanam, this approach enables the derivation of over 100 trigonometric identities through a single, unified approach. The simplicity and efficiency of this technique not only make learning trigonometry more accessible but also foster computational thinking. Beyond academics, the practical applications of this method extend to engineering fields such as bridge design and construction, where precise trigonometric calculations are critical. This exploration underscores the potential of Vedic Mathematics to revolutionize the learning and application of trigonometry by offering a streamlined, intuitive, and versatile framework.

Keywords: baudhayan numbers, anurupyena, vilokanam, sutras

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Authors: Mohammed Seyam, Faridah Othman, Ahmed El-Shafie

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The early warning of high stream flow events (HSF) and floods is an important aspect in the management of surface water and rivers systems. This process can be performed using either process-based models or data driven-based models such as artificial intelligence (AI) techniques. The main goal of this study is to develop efficient AI-based model for predicting the real-time hourly stream flow (Q) and apply it as early warning tool of HSF and floods in the downstream area of the Selangor River basin, taken here as a paradigm of humid tropical rivers in Southeast Asia. The performance of AI-based models has been improved through the integration of the lag time (Lt) estimation in the modelling process. A total of 8753 patterns of Q, water level, and rainfall hourly records representing one-year period (2011) were utilized in the modelling process. Six hydrological scenarios have been arranged through hypothetical cases of input variables to investigate how the changes in RF intensity in upstream stations can lead formation of floods. The initial SF was changed for each scenario in order to include wide range of hydrological situations in this study. The performance evaluation of the developed AI-based model shows that high correlation coefficient (R) between the observed and predicted Q is achieved. The AI-based model has been successfully employed in early warning throughout the advance detection of the hydrological conditions that could lead to formations of floods and HSF, where represented by three levels of severity (i.e., alert, warning, and danger). Based on the results of the scenarios, reaching the danger level in the downstream area required high RF intensity in at least two upstream areas. According to results of applications, it can be concluded that AI-based models are beneficial tools to the local authorities for flood control and awareness.

Keywords: floods, stream flow, hydrological modelling, hydrology, artificial intelligence

Procedia PDF Downloads 250