Search results for: compressive resistance

Authors: Hamid Mohammadi, S. H. Eftekhar Afzali

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The irregular usage of chemical fertilizer cause different types of water and soil pollution and problems in health of human in past decades and organic fertilizer has been considered more and more. Mycorrhizal fungi have symbiosis with plant families and significantly effect on plant growth. Proper management of these symbiosis causes to reduce the usage of chemical fertilizers and absorb nutrition especially phosphor. Pistacia vera is endemic in Iran and is one of the most important products for this country. Considering special circumstances of pistachio orchards according to increasing salinity of water and soil and mismanagement of fertilizer reveals the necessity of the usage of Mycorrhizal fungi in these orchards.

Keywords: pistachio, mycorhiza, nutrition, salinity

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Authors: Rupinder Bakshi, Geeta Walia, Anita Gupta

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Introduction: Urinary tract infections (UTI) are considered to be one of the most common bacterial infections with an estimated annual global incidence of 150 million. Antimicrobial drug resistance is one of the major threats due to widespread usage of uncontrolled antibiotics. Materials and Methods: A total number of 9149 urine samples were collected from R.H Patiala and processed in the Department of Microbiology G.M.C Patiala. Urine samples were inoculated on MacConkey’s and blood agar plates by using calibrated loop delivering 0.001 ml of sample and incubated at 37 °C for 24 hrs. The organisms were identified by colony characters, gram’s staining and biochemical reactions. Antimicrobial susceptibility of the isolates was determined against various antimicrobial agents (Hi – Media Mumbai India) by Kirby-Bauer disk diffusion method on Muller Hinton agar plates. Results: Maximum patients were in the age group of 21-30 yrs followed by 31-40 yrs. Males (34%) are less prone to urinary tract infections than females (66%). Out of 9149 urine sample, the culture was positive in 25% (2290) samples. Esch. coli was the most common isolate 60.3% (n = 1378) followed by Klebsiella pneumoniae 13.5% (n = 310), Proteus spp. 9% (n = 209), Staphylococcus aureus 7.6 % (n = 173), Pseudomonas aeruginosa 3.7% (n = 84), Citrobacter spp. 3.1 % (70), Staphylococcus saprophyticus 1.8 % (n = 142), Enterococcus faecalis 0.8%(n=19) and Acinetobacter spp. 0.2%(n=5). Gram negative isolates showed higher sensitivity towards, Piperacillin +Tazobactum (67%), Amikacin (80%), Nitrofurantoin (82%), Aztreonam (100%), Imipenem (100%) and Meropenam (100%) while gram positive showed good response towards Netilmicin (69%), Nitrofurantoin (79%), Linezolid (98%), Vancomycin (100%) and Teicoplanin (100%). 465 (23%) isolates were resistant to Penicillins, 1st generation and 2nd generation Cehalosporins which were further tested by double disk approximation test and combined disk method for ESBL production. Out of 465 isolates, 375 were ESBLs consisting of n 264 (70.6%) Esch.coli and 111 (29.4%) Klebsiella pneumoniae. Susceptibility of ESBL producers to Imipenem, Nitrofurantoin and Amikacin were found to be 100%, 76%, and 75% respectively. Conclusion: Uropathogens are increasingly showing resistance to many antibiotics making empiric management of outpatients UTIs challenging. Ampicillin, Cotrimoxazole, and Ciprofloxacin should not be used in empiric treatment. Nitrofurantoin could be used in lower urinary tract infection. Knowledge of uropathogens and their antimicrobial susceptibility pattern in a geographical region will help inappropriate and judicious antibiotic usage in a health care setup.

Keywords: Urinary Tract Infection, UTI, antibiotic susceptibility pattern, ESBL

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Authors: Halima Djaaboube, Redha Aouati, Ibtissem Loucif, Yassine Bouachiba, Mouad Chettab, Adel Taabouche, Sihem Abed, Salima Ouendadji, Abderrahmane Bouabellou

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Thin films of pure and barium-doped zinc oxide (ZnO) were prepared using spray pyrolysis process. The films were deposited on glass substrates at 450°C. The different samples are characterized by X-ray diffraction (XRD) and UV-Vis spectroscopy. X-ray diffraction patterns reveal the formation of a single ZnO Wurtzite structure and the good crystallinity of the films. The substitution of Ba ions influences the texture of the layers and makes the (002) plane a preferential growth plane. At concentrations below 6% Ba, the hexagonal structure of ZnO undergoes compressive stresses due to barium ions which have a radius twice of the Zn ions. This result leads to the decrees of a and c parameters and therefore the volume of the unit cell. This result is confirmed by the decrease in the number of crystallites and the increase in the size of the crystallites. At concentrations above 6%, barium substitutes the zinc atom and modifies the structural parameters of the thin layers. The bandgap of ZnO films decreased with increasing doping, this decrease is probably due to the 4d orbitals of the Ba atom due to the sp-d spin-exchange interactions between the band electrons and the localized d-electrons of the substituted Ba ion. Although, the Urbache energy undergoes an increase which implies the creation of energy levels below the conduction band and decreases the band gap width. The photocatalytic activity of ZnO doped 9% Ba was evaluated by the photodegradation of methylene blue under UV irradiation.

Keywords: barium, doping, photodegradation, spray pyrolysis, ZnO.

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Authors: Johannes Bibinger, Sebastian Eibl, Hans-Joachim Gudladt

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This study considers the influence of different irradiation scenarios on the thermal degradation of carbon fiber-reinforced polymers (CFRP). Real threats are simulated, such as fires with long-lasting low heat fluxes and nuclear heat flashes with short-lasting high heat fluxes. For this purpose, coated and uncoated quasi-isotropic samples of the commercially available CFRP HexPly® 8552/IM7 are thermally irradiated from one side by a cone calorimeter and a xenon short-arc lamp with heat fluxes between 5 and 175 W/cm² at varying time intervals. The specimen temperature is recorded on the front and backside as well as at different laminate depths. The CFRP is non-destructively tested with ultrasonic testing, infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and micro-focused computed X-Ray tomography (μCT). Destructive tests are performed to evaluate the mechanical properties in terms of interlaminar shear strength (ILSS), compressive and tensile strength. The irradiation scenarios vary significantly in heat flux and exposure time. Thus, different heating rates, radiation effects, and temperature distributions occur. This leads to unequal decomposition processes, which affect the sensitivity of the strength type and damage behaviour of the specimens. However, with the use of surface coatings, thermal degradation of composite materials can be delayed.

Keywords: CFRP, one-sided thermal damage, high heat flux, heating rate, non-destructive and destructive testing

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Authors: Gurleen Kour, Mowkshi Khullar, B. K. Chandan, Parvinder Pal Singh, Kushalava Reddy Yumpalla, Gurunadham Munagala, Ram A. Vishwakarma, Zabeer Ahmed

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New chemotherapeutic compounds against multidrug-resistant Mycobacterium tuberculosis (Mtb) are urgently needed to combat drug resistance in tuberculosis (TB). Apart from in-vitro potency against the target, physiochemical properties and pharmacokinetic properties play an imperative role in the process of drug discovery. We have identified novel nitroimidazole derivatives with potential activity against mycobacterium tuberculosis. One lead candidates, MCD-017, which showed potent activity against H37Rv strain (MIC=0.5µg/ml) and was further evaluated in the process of drug development. Methods: Basic physicochemical parameters like solubility and lipophilicity (LogP) were evaluated. Thermodynamic solubility was determined in PBS buffer (pH 7.4) using LC/MS-MS. The partition coefficient (Log P) of the compound was determined between octanol and phosphate buffered saline (PBS at pH 7.4) at 25°C by the microscale shake flask method. The compound followed Lipinski’s rule of five, which is predictive of good oral bioavailability and was further evaluated for metabolic stability. In-vitro metabolic stability was determined in rat liver microsomes. The hepatotoxicity of the compound was also determined in HepG2 cell line. In vivo pharmacokinetic profile of the compound after oral dosing was also obtained using balb/c mice. Results: The compound exhibited favorable solubility and lipophilicity. The physical and chemical properties of the compound were made use of as the first determination of drug-like properties. The compound obeyed Lipinski’s rule of five, with molecular weight < 500, number of hydrogen bond donors (HBD) < 5 and number of hydrogen bond acceptors(HBA) not more then 10. The log P of the compound was less than 5 and therefore the compound is predictive of exhibiting good absorption and permeation. Pooled rat liver microsomes were prepared from rat liver homogenate for measuring the metabolic stability. 99% of the compound was not metabolized and remained intact. The compound did not exhibit cytoxicity in hepG2 cells upto 40 µg/ml. The compound revealed good pharmacokinetic profile at a dose of 5mg/kg administered orally with a half life (t1/2) of 1.15 hours, Cmax of 642ng/ml, clearance of 4.84 ml/min/kg and a volume of distribution of 8.05 l/kg. Conclusion : The emergence of multi drug resistance (MDR) and extensively drug resistant (XDR) Tuberculosis emphasize the requirement of novel drugs active against tuberculosis. Thus, the need to evaluate physicochemical and pharmacokinetic properties in the early stages of drug discovery is required to reduce the attrition associated with poor drug exposure. In summary, it can be concluded that MCD-017 may be considered a good candidate for further preclinical and clinical evaluations.

Keywords: mycobacterium tuberculosis, pharmacokinetics, physicochemical properties, hepatotoxicity

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Authors: Mom Bishwakarma

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This research traces out how the Dalit in Nepal evolved from the early 1950s to the current day, from invoking Dalit against caste discrimination through to the asserting proportional representation in state structures. The research focused most closely on the formation of Dalit association and resistance, as well as on the different struggles throughout this period. It then discusses the expansion of Dalit movement in NGOs, its internationalization and responses. The research sees that Dalit movement has been influenced by its network with the national and international civil rights movement particularly Dalit movement in India and argues that Dalit movement in Nepal have in many ways, challenged the orthodox based caste stratification for Dalit equality and justice. It can be seen that at the same time as Dalit participation was increasing, divisions by caste line also emerged. Rather reshaping the power structures, Dalit movement encircled into division and contentious politics.

Keywords: Dalit, equality, justice, movements, Nepal

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Authors: Reham Alwazzan

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Ibn Sina (d. 1037) is perhaps the most important philosopher of the pre-modern era. Among his many contributions, the proof for the existence of the necessary existent stands out. Ibn Sina proceeds to extract each of God’s attributes (sifat) from His necessary existence. Although his ideas met with resistance in some quarters, they found a warm reception in the Akbarian school, particularly in the works of Sadr al-Din al-Qunawi (d. 1274) and ‘Abd al-Razzaq al-Qashani (d. 1335). This paper argues that the influence of Ibn Sina’s concept of necessity (wujub) had a great impact on the founder of the Akbarian school, Muhyi al-Din ibn ‘Arabi (d. 1240). Ibn ‘Arabi reformulates God’s necessary existence (wujud) as God’s necessary/metaphysical mercy (rahma) in order to extract all of the divine names from this primary attribute of God. Even as he denies all influences and insists his work is the product of spiritual unveiling (kashf), Ibn ‘Arabi seems to be following the same path delineated by his illustrious predecessor, if in his own way.

Keywords: existence, Ibn ‘Arabi, Ibn Sina, mercy, necessity

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Authors: Mohammad Moonesun

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One of the most important future technologies is related to solar Autonomous Underwater Vehicles (AUVs). In this technical paper, some aspects of solar winged AUV design are mentioned. The case study is for Arya project. The submarine movement cyclograms, weight quotas for internal equipment, hydrodynamic test results are mentioned, and some other technical notes are discussed here. The main body is the SUBOFF type and has two hydroplanes on the both sides of the body with the NACA0015 cross section. On these two hydroplanes, two 50-W photovoltaic panel will be mounted. Four small hydroplanes with the same cross section of the NACA0015 are arranged at the stern of the body at a 90° angle to each other. This test is performed in National Iranian Marine Laboratory with the length of 402 m.

Keywords: AUV, solar, model test, hydrodynamic resistance

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Authors: Aymen Arfaoui, Abdelkader Soumaya, Ali Kadri, Noureddine Ben Ayed

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The Tunisian dorsal backland is located on the Eastern Atlas side of the Maghrebides (North Africa). The analysis of collected field data in the Rouas and Ruissate mountains area allowed us to develop new interpretations for its structural framework. Our kinematic analysis of fault-slip data reveals the presence of an extensional tectonic regime with NE-SW Shmin, characterizing the Mesozoic times. In addition, geophysical data shows that the synsedimentary normal faulting is accompanied by thickness variations of sedimentary sequences and Triassic salt movements. Then, after the Eurasia-Africa plate’s convergence during the Eocene, compressive tectonic deformations affected and reactivated the inherited NW-SE and N-S trending normal faults as dextral strike-slip and reverse faults, respectively. This tectonic inversion, with compression to the transpressional tectonic regime and NW-SE SHmax, continued during the successive shortening phases of the upper Miocene and Quaternary. The geometry of the Rouas and Ruissate belt is expressed as a fault propagation fold, affecting Jurassic and Cretaceous deposits. The Triassic evaporates constitute the decollement levels, facilitating the detachment and deformation of the sedimentary cover. The backland of this thrust belt is defined by NNE-SSW trending imbrication features that are controlled by a basement N-S fault.

Keywords: Tunisian dorsal backland, fault slip data; synsedimentary faults, tectonic inversion, decollement level, fault propagation fold

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Authors: Rideci Farias, Haroldo Paranhos

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The present work deals with the use of drainage geo-composite as a deep drainage and geogrid element to reinforce the base of the body of the landfill destined to the road pavement on geological faults in the stretch of the TO-342 Highway, between the cities of Miracema and Miranorte, in the State of Tocantins / TO, Brazil, which for many years was the main link between TO-010 and BR-153, after the city of Palmas, also in the state of Tocantins / TO, Brazil. For this application, geotechnical and geological studies were carried out by means of SPT percussion drilling, drilling and rotary drilling, to understand the problem, identifying the type of faults, filling material and the definition of the water table. According to the geological and geotechnical studies carried out, the area where the route was defined, passes through a zone of longitudinal fault to the runway, with strong breaking / fracturing, with presence of voids, intense alteration and with advanced argilization of the rock and with the filling up parts of the faults by organic and compressible soils leachate from other horizons. This geology presents as a geotechnical aggravating agent a medium of high hydraulic load and very low resistance to penetration. For more than 20 years, the region presented constant excessive deformations in the upper layers of the pavement, which after routine services of regularization, reconformation, re-compaction of the layers and application of the asphalt coating. The faults were quickly propagated to the surface of the asphalt pavement, generating a longitudinal shear, forming steps (unevenness), close to 40 cm, causing numerous accidents and discomfort to the drivers, since the geometric positioning was in a horizontal curve. Several projects were presented to the region's highway department to solve the problem. Due to the need for partial closure of the runway, the short time for execution, the use of geosynthetics was proposed and the most adequate solution for the problem was taken into account the movement of existing geological faults and the position of the water level in relation to several Layers of pavement and failure. In order to avoid any flow of water in the body of the landfill and in the filling material of the faults, a drainage curtain solution was used, carried out at 4.0 meters depth, with drainage geo-composite and as reinforcement element and inhibitor of the possible A geogrid of 200 kN / m of resistance was inserted at the base of the reconstituted landfill. Recent evaluations, after 13 years of application of the solution, show the efficiency of the technique used, supported by the geotechnical studies carried out in the area.

Keywords: geosynthetics, geocomposite, geogrid, road, recovery, geological failure

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Authors: G. Nitesh

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The shear strength of soils is a crucial parameter instability analysis. Therefore, it is important to determine reliable values for the accuracy of stability analysis. Direct shear tests are mostly performed to determine the shear strength of cohesionless soils. The major limitation of the direct shear test is that the failure takes place through the pre-defined failure plane but the failure is not along pre-defined plane and is along the weakest plane in actual shearing mechanism that goes on in the field. This leads to overestimating the strength parameter; hence, a new apparatus called simple shear is developed and used in this study to determine the shear strength parameter that simulates the field conditions.

Keywords: direct shear, simple shear, angle of shear resistance, cohesionless soils

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Authors: Yiqiang Ni, Xuanlong Chen, Enliang Li, Linting Zheng, Shizheng Yang

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Bipolar ICs are playing an important role in military applications, mainly used in logic gates, such as inverter and NAND gate. The defect of metal break located on the step is one of the main failure mechanisms of bipolar ICs, resulting in open-circuit or functional failure. In this situation, general failure localization methods like optical beam-induced resistance change (OBIRCH) and photon emission microscopy (PEM) might not be fully effective. However, active voltage contrast (AVC) can be used as a voltage probe, which may pinpoint the incorrect potential and thus locate the failure position. Two case studies will be present in this paper on how to implement AVC for failure localization, and the detailed failure mechanism will be discussed.

Keywords: bipolar IC, failure localization, metal break, open failure, voltage contrast

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Authors: Robin Anderson, Elizabeth Latham, David Nisbet

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Propagation and dissemination of antimicrobial resistant and pathogenic microbes from spoiled silages and composts represents a serious public health threat to humans and animals. In the present study, the antimicrobial activity of the short chain nitro-compound, 2-nitro-1-propanol (9 mM) as well as the medium chain fatty acid, lauric acid, and its glycerol monoester, monolaurin, (each at 25 and 17 µmol/mL, respectfully) were investigated against select pathogenic and multi-drug resistant antimicrobial resistant Gram-positive bacteria common to spoiled silages and composts. In an initial study, we found that growth rates of a multi-resistant Enterococcus faecalis (expressing resistance against erythromycin, quinupristin/dalfopristin and tetracycline) and Staphylococcus aureus strain 12600 (expressing resistance against erythromycin, linezolid, penicillin, quinupristin/dalfopristin and vancomycin) were more than 78% slower (P < 0.05) by 2-nitro-1-propanol treatment during culture (n = 3/treatment) in anaerobically prepared ½ strength Brain Heart Infusion broth at 37oC when compared to untreated controls (0.332 ± 0.04 and 0.108 ± 0.03 h-1, respectively). The growth rate of 2-nitro-1-propanol-treated Listeria monocytogenes was also decreased by 96% (P < 0.05) when compared to untreated controls cultured similarly (0.171 ± 0.01 h-1). Maximum optical densities measured at 600 nm were lower (P < 0.05) in 2-nitro-1-propanol-treated cultures (0.053 ± 0.01, 0.205 ± 0.02 and 0.041 ± 0.01, respectively) than in untreated controls (0.483 ± 0.02, 0.523 ± 0.01 and 0.427 ± 0.01, respectively) for E. faecalis, S. aureus and L. monocytogenes, respectively. When tested against mixed microbial populations during anaerobic 24 h incubation of spoiled silage, significant effects of treatment with 1 mg 2-nitro-1-propanol (approximately 9.5 µmol/g) or 5 mg lauric acid/g (approximately 25 µmol/g) on populations of wildtype Enterococcus and Listeria were not observed. Mixed populations treated with 5 mg monolaurin/g (approximately 17 µmol/g) had lower (P < 0.05) viable cell counts of wildtype enterococci than untreated controls after 6 h incubation (2.87 ± 1.03 versus 5.20 ± 0.25 log10 colony forming units/g, respectively) but otherwise significant effects of monolaurin were not observed. These results reveal differential susceptibility of multi-drug resistant enterococci and staphylococci as well as L. monocytogenes to the inhibitory activity of 2-nitro-1-propanol and the medium chain fatty acid, lauric acid and its glycerol monoester, monolaurin. Ultimately, these results may lead to improved treatment technologies to preserve the microbiological safety of silages and composts.

Keywords: 2-nitro-1-propanol, lauric acid, monolaurin, gram positive bacteria

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Authors: Roman Knizek, Denisa Karhankova, Ludmila Fridrichova

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For their exceptional properties nanofibers, respectively, nanofiber layers are achieving an increasingly wider range of uses. Nowadays nanofibers are used mainly in the field of air filtration where they are removing submicron particles, bacteria, and viruses. Their efficiency is not changed in time, and the power consumption is much lower than that of electrically charged filters. Nanofibers are primarily used for converting and storage of energy in both air and liquid filtration, in food and packaging, protecting the environment, but also in health care which is made possible by their newly discovered properties. However, a major problem of the nanofiber layer is practically zero abrasion resistance; it is, therefore, necessary to laminate the nanofiber layer with another suitable material. Unfortunately, lamination of nanofiber layers is a major problem since the nanofiber layer contains small pores through which it is very difficult for adhesion to pass through. Therefore, there is still only a small percentage of products with these unique fibers 5.

Keywords: nanofiber layer, nanomembrane, lamination, electrospinning

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Authors: R. Bensaada, M. Almansba, M. Ould Ouali, R. Ferhoum, N. E. Hannachi

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The aim of this work is to simulate the ductile fracture of SEN specimens in aluminium alloy. The assessment of fracture toughness is performed with the calculation of Jc (the critical value of J-Integral) through the resistance curves. The study is done using finite element code calculation ABAQUSTM including an elastic plastic with damage model of material’s behaviour. The procedure involves specimens of four different thicknesses and four ligament sizes for every thickness. The material of study is an aluminium alloy 6061-T6 for which the necessary parameters to complete the study are given. We found the same results for the same specimen’s thickness and for different ligament sizes when the fracture criterion is evaluated.

Keywords: j-integral, critical-j, damage, fracture toughness

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Authors: Dosu Malomo, O. E. Edeh, P. O. Okolo, F. C. Ibeh

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The preparation of various samples of ebonite vulcanizates and their physico-mechanical properties have been investigated using standard methods. This work explores the production of ebonite dust, production of ebonite vulcanizates and investigation of the characterisation of the ebonite. Five different ebonite materials – labelled A, B, C, D, and E with sulphur content in parts per hundred grams of rubber (Phr) of 32, 34, 36, 38 and 40 respectively were produced. The physico-mechanical properties carried out were tensile strength, hardness and abrasion resistance. The tensile strength (MPa) for sample A, B, C, D and E were 5.6, 3.5, 4.7, 1.7 and 2.0 respectively while the abrasion(%mass loss) were 8.49, 4.24, 2.59, 1.08 and 1.05 respectively and the hardness (IRHD) being 63, 64, 65, 70 and 82. The results show that the preparation of ebonite from natural rubber as a base polymer is feasible considering the results of characterisation obtained.

Keywords: compounding, ebonite dust, natural rubber, vulcanization

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Authors: S. Abou El-Azm, U. Kruchonak, M. Gostkin, A. Guskov, A. Zhemchugov

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Semiconductor detectors are widely used in nuclear physics and high-energy physics experiments. The application of semiconductor detectors could be limited by their ultimate radiation resistance. The increase of radiation defects concentration leads to significant degradation of the working parameters of semiconductor detectors. The investigation of radiation defects properties in order to enhance the radiation hardness of semiconductor detectors is an important task for the successful implementation of a number of nuclear physics experiments; we presented some information about radiation hardness materials like diamond, sapphire and CdTe. Also, the results of measurements I-V characteristics, charge collection efficiency and its dependence on the bias voltage for different doses of high resistivity (GaAs: Cr) and Si at LINAC-200 accelerator and reactor IBR-2 are presented.

Keywords: semiconductor detectors, radiation hardness, GaAs, Si, CCE, I-V, C-V

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Authors: K. Bala Subramanian, A. Siva, S. Swaminathan, Arul. M. G. Ajin

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Concrete is an essential building material which is widely used in construction industry all over the world due to its compressible strength. Curing of concrete plays a vital role in durability and other performance necessities. Improper curing can affect the concrete performance and durability easily. When areas like scarcity of water, structures is not accessible by humans external curing cannot be performed, so we opt for internal curing. Internal curing (or) self-curing plays a major role in developing the concrete pore structure and microstructure. The concept of internal curing is to enhance the hydration process to maintain the temperature uniformly. The evaporation of water in the concrete is reduced by self-curing agent (Super Absorbing Polymer – SAP) thereby increasing the water retention capacity of the concrete. The research work was carried out to reduce water, which is prime material used for concrete in the construction industry. Concrete curing plays a major role in developing hydration process. Concept of self-curing will reduce the evaporation of water from concrete. Self-curing will increase water retention capacity as compared to the conventional concrete. Proper self-curing (or) internal curing increases the strength, durability and performance of concrete. Super absorbing Polymer (SAP) used as internal curing agent. In this study 0.2% to 0.4% of SAP was varied in different grade of high strength concrete. In the experiment replacement of cement by silica fumes with 5%, 10% and 15% are studied. It is found that replacement of silica fumes by 10 % gives more strength and durability when compared to others

Keywords: compressive strength, high strength concrete rapid chloride permeability, super absorbing polymer

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Authors: Aidoud Assia, Bencheikh Messaouda, Boukour Salima

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Polystyrene is often seen in the ocean and on Algerian beaches, mainly as food containers. It's one of the top 10 most common items found there. This happens because it's light and easily carried away from its original source, like packaging or transport, into the environment. Unfortunately, it's not recycled much because it's not very profitable to do so. Hence, turning this waste into a resource can turn challenges into opportunities for a territory's economic and environmental development, which is the focus of this study. the goal is to analyze the physical and mechanical properties of a new type of mortar made from dune sand mixed with recycled polystyrene. it also aim to assess its potential for use in various construction applications. The mixtures were prepared by replacing portions of dune sand with polystyrene waste at varying volumes (10%, 20%, and 30%), while keeping the amount of cement constant. The results indicate a noticeable impact on both the physical and mechanical properties because of incorporating polystyrene waste.

Keywords: polystyrène, eco-mortier, sable de dune, résistance

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Authors: Viriyavudh Sim, WooYoung Jung

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Damage due to high wind is not limited to load resistance components such as beam and column. The majority of damage is due to breach in the building envelope such as broken roof, window, and door. In this paper, wind fragility of window glass in residential apartment was determined to compare the difference between two window configuration models. Monte Carlo Simulation method had been used to derive damage data and analytical fragilities were constructed. Fragility of window system showed that window located in leeward wall had higher probability of failure, especially those close to the edge of structure. Between the two window models, Model 2 had higher probability of failure, this was due to the number of panel in this configuration.

Keywords: wind fragility, glass window, high rise building, wind disaster

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Authors: Laura Dembovska, Diana Bajare, Ina Pundiene, Daira Erdmane

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The aim of this research is to estimate effect of pozzolanic substitutes and their combination on the hydration heat and final strength of high performance concrete. Ternary cementitious systems with different ratios of ordinary Portland cement, silica fume and calcined clay were investigated. Local illite clay was calcined at temperature 700oC in rotary furnace for 20 min. It has been well recognized that the use of pozzolanic materials such as silica fume or calcined clay are recommended for high performance concrete for reduction of porosity, increasing density and as a consequence raising the chemical durability of the concrete. It has been found, that silica fume has a superior influence on the strength development of concrete, but calcined clay increase density and decrease size of dominating pores. Additionally it was found that the rates of pozzolanic reaction and calcium hydroxide consumption in the silica fume-blended cement pastes are higher than in the illite clay-blended cement pastes, it strongly depends from the amount of pozzolanic substitutes which are used. If the pozzolanic reaction is dominating then amount of Ca(OH)2 is decreasing. The identity and the amount of the phases present were determined from the thermal analysis (DTA) data. The hydration temperature of blended cement pastes was measured during the first 24 hours. Fresh and hardened concrete properties were tested. Compressive strength was determined and differential thermal analysis (DTA) was conducted of specimens at the age of 3, 14, 28 and 56 days.

Keywords: high performance concrete, pozzolanic additives, silica fume, ternary systems

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Authors: Raj Kumar Rajak, Bharat Mishra

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Bio-battery represents an entirely new long term, reasonable, reachable and ecofriendly approach to production of sustainable energy. Types of batteries have been developed using MnO₂ in various ways. MnO₂ is suitable with physical, chemical, electrochemical, and catalytic properties, serving as an effective cathodic depolarizer and may be considered as being the life blood of the battery systems. In the present experimental work, we have studied the effect of generation of power by bio-battery using different concentrations of MnO₂. The tests show that it is possible to generate electricity using cow’s urine as an electrolyte. After ascertaining the optimum concentration of MnO₂, various battery parameters and performance indicates that cow urine solely produces power of 695 mW, while a combination with MnO₂ (40%) enhances power of bio-battery, i.e. 1377 mW. On adding more and more MnO₂ to the electrolyte, the power suppressed because inflation of internal resistance. The analysis of the data produced from experiment shows that MnO₂ is quite suitable to energize the bio-battery.

Keywords: bio-batteries, cow’s urine, manganese dioxide, non-conventional

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Authors: A. Jatau, H. M. Bandiya, Q. Majeed, M. A. Yahaya

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An investigation on the insect infestation of stored seeds of cowpea seeds varieties (Sokoto Loacal and Kanannado) was carried out in Sokoto central market, Sokoto. Two insects' species, Callosobrunchus maculatus and Callosobrunchus chinensis were found on the stored seeds with C. maculutus found to be the most prevalent. The rate of infestation of the cowpea seeds by the two insect species were significantly (P< 0.05) higher in Sokoto local than in Kanannado variety. The result shows that kanannado variety is more resistance to cowpea seeds weevils, hence should be used for long storage in Sokoto.

Keywords: insect, infestation, cowpea seeds, grainaries

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Authors: Trunal Bhujangrao, Catherine Froustey, Fernando Veiga, Philippe Darnis, Franck Girot Mata

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The understanding of the material behavior under shear loading has great importance for a researcher in manufacturing processes like cutting, machining, milling, turning, friction stir welding, etc. where the material experiences large deformation at high temperature. For such material behavior analysis, hot shear tests provide a useful means to investigate the evolution of the microstructure at a wide range of temperature and to improve the material behavior model. Shear tests can be performed by direct shear loading (e.g. torsion of thin-walled tubular samples), or appropriate specimen design to convert a tensile or compressive load into shear (e.g. simple shear tests). The simple shear tests are straightforward and designed to obtained very large deformation. However, many of these shear tests are concerned only with the elastic response of the material. It is becoming increasingly important to capture a plastic response of the material. Plastic deformation is significantly more complex and is known to depend more heavily on the strain rate, temperature, deformation, etc. Besides, there is not enough work is done on high-temperature shear loading, because of geometrical instability occurred during the plastic deformation. The aim of this study is to design a new shear tensile specimen geometry to convert the tensile load into dominant shear loading under plastic deformation. Design of the specimen geometry is based on FEM. The material used in this paper is AA7075 alloy, tested quasi statically under elevated temperature. Finally, the microstructural changes taking place during

Keywords: AA7075 alloy, dynamic recrystallization, edge effect, large strain, shear tensile test

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Authors: Ying-Chang Yu, Yuan-Lung Lo

Abstract:

Building envelope design is one of the most popular design fields of architectural profession in nowadays. The main design trend of such system is to highlight the designer's aesthetic intention from the outlook of building project. Due to the trend of current façade design, the building envelope contains more and more layers of components, such as double skin façade, photovoltaic panels, solar control system, or even ornamental components. These exterior components are designed for various functional purposes. Most researchers focus on how these exterior elements should be structurally sound secured. However, not many researchers consider these elements would help to improve the performance of façade system. When the exterior elements are deployed in large scale, it creates an additional layer outside of original façade system and acts like a porous interface which would interfere with the aerodynamic of façade surface in micro-scale. A standard façade performance consists with 'water penetration, air infiltration rate, operation force, and component deflection ratio', and these key performances are majorly driven by the 'Design Wind Load' coded in local regulation. A design wind load is usually determined by the maximum wind pressure which occurs on the surface due to the geometry or location of building in extreme conditions. This research was designed to identify the air damping phenomenon of micro turbulence caused by porous exterior layer leading to surface wind load reduction for improvement of façade system performance. A series of wind tunnel test on dynamic pressure sensor array covered by various scale of porous exterior skin was conducted to verify the effect of wind pressure reduction. The testing specimens were designed to simulate the typical building with two-meter extension offsetting from building surface. Multiple porous exterior skins were prepared to replicate various opening ratio of surface which may cause different level of damping effect. This research adopted 'Pitot static tube', 'Thermal anemometers', and 'Hot film probe' to collect the data of surface dynamic pressure behind porous skin. Turbulence and distributed resistance are the two main factors of aerodynamic which would reduce the actual wind pressure. From initiative observation, the reading of surface wind pressure was effectively reduced behind porous media. In such case, an actual building envelope system may be benefited by porous skin from the reduction of surface wind pressure, which may improve the performance of envelope system consequently.

Keywords: multi-layer facade, porous media, facade performance, turbulence and distributed resistance, wind tunnel test

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Authors: Supunmali Ahangama, Danny Chiang Choon Poo

Abstract:

Health analytics (HA) is used in healthcare systems for effective decision-making, management, and planning of healthcare and related activities. However, user resistance, the unique position of medical data content, and structure (including heterogeneous and unstructured data) and impromptu HA projects have held up the progress in HA applications. Notably, the accuracy of outcomes depends on the skills and the domain knowledge of the data analyst working on the healthcare data. The success of HA depends on having a sound process model, effective project management and availability of supporting tools. Thus, to overcome these challenges through an effective process model, we propose an HA process model with features from the rational unified process (RUP) model and agile methodology.

Keywords: agile methodology, health analytics, unified process model, UML

Procedia PDF Downloads 486

Authors: M. L. Dinis, M. C. Vila, A. Fiúza, A. Futuro, C. Nunes

Abstract:

The present paper describes the study of paste tailings prepared in laboratory using gold tailings, produced in a Finnish gold mine with the incorporation of coal ash. Natural leaching tests were conducted with the original materials (tailings, fly and bottom ashes) and also with paste mixtures that were prepared with different percentages of tailings and ashes. After leaching, the solid wastes were physically and chemically characterized and the results were compared to those selected as blank – the unleached samples. The tailings and the coal ash, as well as the prepared mixtures, were characterized, in addition to the textural parameters, by the following measurements: grain size distribution, chemical composition and pH. Mixtures were also tested in order to characterize their mechanical behavior by measuring the flexural strength, the compressive strength and the consistency. The original tailing samples presented an alkaline pH because during their processing they were previously submitted to pressure oxidation with destruction of the sulfides. Therefore, it was not possible to ascertain the effect of the coal ashes in the acid mine drainage. However, it was possible to verify that the paste reactivity was affected mostly by the bottom ash and that the tailings blended with bottom ash present lower mechanical strength than when blended with a combination of fly and bottom ash. Surface paste disposal offer an attractive alternative to traditional methods in addition to the environmental benefits of incorporating large-volume wastes (e.g. bottom ash). However, a comprehensive characterization of the paste mixtures is crucial to optimize paste design in order to enhance engineer and environmental properties.

Keywords: coal ash, mine tailings, paste blends, surface disposal

Procedia PDF Downloads 275

Authors: Mustafa Engin Başoğlu, Bekir Çakır

Abstract:

The most important component affecting the efficiency of photovoltaic power systems are solar panels. Efficiency of these systems are significantly affected because of being low efficiency of solar panel. Therefore, solar panels should be operated under maximum power point conditions through a power converter. In this study, design boost converter with maximum power point tracking (MPPT) operation has been designed and performed with Incremental Conductance (Inc-Cond) algorithm by using direct duty control. Furthermore, it is shown that performance of boost converter with MPPT operation fails under low load resistance connection.

Keywords: boost converter, incremental conductance (Inc-Cond), MPPT, solar panel

Procedia PDF Downloads 1026

Authors: Amir Mahmoudi

Abstract:

In this investigation, AISI321 steel after welding by Shilded Metal Arc Welding (SMAW) was solution heat treated in various temperatures and times, and then was sensitizied. Results indicated, increasing of temperature in solution heat treatment raises the sensitization and creates the cavity structure in grain boundaries. Besides, in order to examine the effect of time on solution heat treatment, all samples were solution heat treated at different times and fixed temperature (1050°C). By increasing the time, more chrome carbides were created due to dissolution of delta ferrite phase and reproduce titanium carbides. Additionally, the best process for solution heat treatment for this steel was suggested.

Keywords: stainless steel, solution heat treatment, intergranular corrosion, DLEPR

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Authors: Natalia Espinosa, Arthur Amorim, Rudolf Huebner

Abstract:

Epilepsy is a chronic neural disease and around 50 million people in the world suffer from this disease, however, in many cases, the individual acquires resistance to the medication, which is known as drug-resistant epilepsy, where a detection system is necessary. This paper showed the development of an automatic system for seizure detection based on artificial neural networks (ANN), which are common techniques of machine learning. Discrete Wavelet Transform (DWT) is used for decomposing electroencephalogram (EEG) signal into main brain waves, with these frequency bands is extracted features for training a feedforward neural network with backpropagation, finally made a pattern classification, seizure or non-seizure. Obtaining 95% accuracy in epileptic EEG and 100% in normal EEG.

Keywords: Artificial Neural Network (ANN), Discrete Wavelet Transform (DWT), Epilepsy Detection , Seizure.

Procedia PDF Downloads 192