Search results for: resistance spot welding

Authors: V. Ziegler, F. Schneider, M. Pesch

Abstract:

With the EDM264, GRIMM offers a solution for mobile short- and long-term measurements in outdoor areas and at production sites. For research as well as permanent areal observations on a near reference quality base. The model EDM264 features a powerful and robust measuring cell based on optical particle counting (OPC) principle with all the advantages that users of GRIMM's portable aerosol spectrometers are used to. The system is embedded in a compact weather-protection housing with all-weather sampling, heated inlet system, data logger, and meteorological sensor. With TSP, PM10, PM4, PM2.5, PM1, and PMcoarse, the EDM264 provides all fine dust fractions real-time, valid for outdoor applications and calculated with the proven GRIMM enviro-algorithm, as well as six additional dust mass fractions pm10, pm2.5, pm1, inhalable, thoracic and respirable for IAQ and workplace measurements. This highly versatile instrument performs real-time monitoring of particle number, particle size and provides information on particle surface distribution as well as dust mass distribution. GRIMM's EDM264 has 31 equidistant size channels, which are PSL traceable. A high-end data logger enables data acquisition and wireless communication via LTE, WLAN, or wired via Ethernet. Backup copies of the measurement data are stored in the device directly. The rinsing air function, which protects the laser and detector in the optical cell, further increases the reliability and long term stability of the EDM264 under different environmental and climatic conditions. The entire sample volume flow of 1.2 L/min is analyzed by 100% in the optical cell, which assures excellent counting efficiency at low and high concentrations and complies with the ISO 21501-1standard for OPCs. With all these features, the EDM264 is a world-leading dust monitor for precise monitoring of particulate matter and particle number concentration. This highly reliable instrument is an indispensable tool for many users who need to measure aerosol levels and air quality outdoors, on construction sites, or at production facilities.

Keywords: aerosol research, aerial observation, fence line monitoring, wild fire detection

Procedia PDF Downloads 151

Authors: Burçak Boztemur, Yue Xu, Laima Luo, M. Lütfi Öveçoğlu, Duygu Ağaoğulları

Abstract:

Tungsten (W) is used chiefly as plasma-facing material. However, it has some problems, such as brittleness after plasma exposure. High-entropy alloys (RHEAs) are a new opportunity for this deficiency. So, the neutron shielding behavior of WNbMoVTa and WNbMoVTaCr₀.₅Al compositions were examined against He⁺ irradiation in this study. The mechanical and irradiation properties of the WNbMoVTa base composition were investigated by adding the Al and Cr elements. The mechanical alloying (MA) for 6 hours was applied to obtain RHEA powders. According to the X-ray diffraction (XRD) method, the body-centered cubic (BCC) phase and NbTa phase with a small amount of WC impurity that comes from vials and balls were determined after 6 h MA. Also, RHEA powders were consolidated with the spark plasma sintering (SPS) method (1500 ºC, 30 MPa, and 10 min). After the SPS method, (Nb,Ta)C and W₂C₀.₈₅ phases were obtained with the decomposition of WC and stearic acid that is added during MA based on XRD results. Also, the BCC phase was obtained for both samples. While the Al₂O₃ phase with a small intensity was seen for the WNbMoVTaCr₀.₅Al sample, the Ta₂VO₆ phase was determined for the base sample. These phases were observed as three different regions according to scanning electron microscopy (SEM). All elements were distributed homogeneously on the white region by measuring an electron probe micro-analyzer (EPMA) coupled with a wavelength dispersive spectroscope (WDS). Also, the grey region of the WNbMoVTa sample was rich in Ta, V, and O elements. However, the amount of Al and O elements was higher for the grey region of the WNbMoVTaCr₀.₅Al sample. The high amount of Nb, Ta, and C elements were determined for both samples. Archimedes’ densities that were measured with alcohol media were closer to the theoretical densities of RHEAs. These values were important for the microhardness and irradiation resistance of compositions. While the Vickers microhardness value of the WNbMoVTa sample was measured as ~11 GPa, this value increased to nearly 13 GPa with the WNbMoVTaCr₀.₅Al sample. These values were compatible with the wear behavior. The wear volume loss was decreased to 0.16×10⁻⁴ from 1.25×10⁻⁴ mm³ by the addition of Al and Cr elements to the WNbMoVTa. The He⁺ irradiation was conducted on the samples to observe surface damage. After irradiation, the XRD patterns were shifted to the left because of defects and dislocations. He⁺ ions were infused under the surface, so they created the lattice expansion. The peak shifting of the WNbMoVTaCr₀.₅Al sample was less than the WNbMoVTa base sample, thanks to less impact. A small amount of fuzz was observed for the base sample. This structure was removed and transformed into a wavy structure with the addition of Cr and Al elements. Also, the deformation hardening was actualized after irradiation. A lower amount of hardening was obtained with the WNbMoVTaCr₀.₅Al sample based on the changing microhardness values. The surface deformation was decreased in the WNbMoVTaCr₀.₅Al sample.

Keywords: refractory high entropy alloy, microhardness, wear resistance, He⁺ irradiation

Procedia PDF Downloads 65

Authors: Dahliz Abderrahmène, Lakhdari Wassim, Bouchikh Yamina, Hammi Hamida, Soud Adila, M’lik Randa, Benglia Sara

Abstract:

Devastating insects constitute one of strains for cultivate tomato. Among this vandal insects, the tomato leafminer (T. absoluta), which has been introduced in Algeria constitute a challenge for both agricultures and scientists. Firstly, this insect is introduced without their natural enemies which may reduce their damage. Secondly, this species has developed insecticide resistance to many active matters. To contribute to establish a control strategy for T. absoluta we have mad an inventory for their enthomopathogenic fungi. Two fungi were identified among others taken from adults and pupae. These fungi are Aspergillus flavus and Metarhizium sp. A study was conducted in laboratory to recognize the efficiency of these antagonists. These species had unregistered a mortality mounts of 42% and 56% respectively.

Keywords: Tuta absoluta, enthomopathogenic fungi, Aspergillus flavus, Metarhizium sp, control strategy

Procedia PDF Downloads 455

Authors: Arthur Thirion

Abstract:

Auxetic geometries allow the generation of a negative Poisson ratio (NPR) in conventional materials. This behaviour allows materials to have certain improved mechanical properties, including impact resistance and altered synclastic behaviour. This means these structures have significant potential when it comes to applications as chronic wound dressings. To this end, 6 different "perforated sheet" structure types were 3D printed. These structures all had variations of key geometrical features included cell length and angle. These were tested in compression and tension to assess their Poisson ratio. Both a positive and negative Poisson ratio was generated by the structures depending on the loading. The a/b ratio followed by θ has been shown to impact the Poisson ratio significantly. There is still a significant discrepancy between modelled and observed behaviour.

Keywords: auxetic materials, 3D printing, negative Poisson's ratio, tunable Poisson's ratio

Procedia PDF Downloads 117

Authors: R. Ziaie Moayed, M. Alibolandi

Abstract:

Dynamic behavior of soil are evaluated relative to a number of factors including: strain level, density, number of cycles, material type, fine content, geosynthetic inclusion, saturation, and effective stress. This paper investigate the dynamic behavior of saturated reinforced sand under cyclic stress condition. The cyclic triaxial tests are conducted on remolded specimens under various CSR which reinforced by different arrangement of non-woven geotextile. Aforementioned tests simulate field reinforced saturated deposits during earthquake or other cyclic loadings. This analysis revealed that the geotextile arrangement played dominant role on dynamic soil behavior and as geotextile close to top of specimen, the liquefaction resistance increased.

Keywords: dynamic behavior, reinforced sand, triaxial test, non-woven geotextile

Procedia PDF Downloads 237

Authors: Jeff Moussodji, Dominique Drouin

Abstract:

The highly complex technology requirements of today’s integrated circuits (ICs), lead to the increased use of several materials types such as metal structures, brittle and porous low-k materials which are used in both front end of line (FEOL) and back end of line (BEOL) process for wafer manufacturing. In order to singulate chip from wafer, a critical laser-grooving process, prior to blade dicing, is used to remove these layers of materials out of the dicing street. The combination of laser-grooving and blade dicing allows to reduce the potential risk of induced mechanical defects such micro-cracks, chipping, on the wafer top surface where circuitry is located. It seems, therefore, essential to have a fundamental understanding of the physics involving laser-dicing in order to maximize control of these critical process and reduce their undesirable effects on process efficiency, quality, and reliability. In this paper, the study was based on the convergence of two approaches, numerical and experimental studies which allowed us to investigate the interaction of a nanosecond pulsed laser and BEOL wafer materials. To evaluate this interaction, several laser grooved samples were compared with finite element modeling, in which three different aspects; phase change, thermo-mechanical and optic sensitive parameters were considered. The mathematical model makes it possible to highlight a groove profile (depth, width, etc.) of a single pulse or multi-pulses on BEOL wafer material. Moreover, the heat affected zone, and thermo-mechanical stress can be also predicted as a function of laser operating parameters (power, frequency, spot size, defocus, speed, etc.). After modeling validation and calibration, a satisfying correlation between experiment and modeling, results have been observed in terms of groove depth, width and heat affected zone. The study proposed in this work is a first step toward implementing a quick assessment tool for design and debug of multiple laser grooving conditions with limited experiments on hardware in industrial application. More correlations and validation tests are in progress and will be included in the full paper.

Keywords: laser-dicing, nano-second pulsed laser, wafer multi-stack, multiphysics modeling

Procedia PDF Downloads 209

Authors: Butchi Kameswara Rao Chittem, Rooban Kumar

Abstract:

Cement concrete is a complex mixture of different materials. Concrete is believed to have a good fire resistance. Behaviour of concrete depends on its mix proportions and its constituent materials when it is subjected to elevated temperatures. Loss in compressive strength, loss in weight or mass, change in colour and spall of concrete are reported in literature as effects of elevated temperature on concrete. In this paper results are reported on the behaviour of normal strength concrete and high strength concrete subjected to temperatures 200°C, 400°C, 600°C, and 800°C and different cooling regimes viz. air cooling, water quenching. Rebound hammer test was also conducted to study the changes in surface hardness of concrete specimens subjected to elevated temperatures.

Keywords: normal strength concrete, high-strength concrete, temperature, NDT

Procedia PDF Downloads 441

Authors: Viera Zatkalíková, Lenka Markovičová, Aneta Tor-Swiatek

Abstract:

The effect of molybdate addition to chloride environment on resistance of AISI 316Ti stainless steel to pitting corrosion was studied. Potentiodynamic polarisation tests were performed in 1 M and 0.1 M chloride acidified solutions with various additions of sodium molybdate at room temperature. The presented results compare the effect of molybdate anions on quality of passive film (expressed by the pitting potential) in both chloride solutions. The pitting potential increases with the increase inhibitor concentration. The inhibitive effect of molybdate ions is stronger in chloride solution of lower aggressiveness (0.1M).

Keywords: AISI 316Ti steel, molybdate inhibitor, pitting corrosion, pitting potential, potentiodynamic polarisation

Procedia PDF Downloads 391

Authors: Yener Tekeli, Hayri Baba

Abstract:

The natural active compounds found in medicinal plants are belong to various chemical structures including polyphenolic compounds, flavonoids, essential oils, and vitamins and some of these compounds have anticancer, antioxidant, and antimicrobial activity. However, these compounds have been little known about mechanisms to confer antibacterial drug resistance. In this study; some macrofungi extracts (Pholiota lucifera, Gnaoderma applanatum and Pleurotus ostreatus) were investigated for their abilities to enhance bacterial permeability by flow cytometry. This experiments exhibited enhancement of these extracts to disrupt the cytoplasmic membrane of living bacterial (Listeria innocua and Escherichia coli) cells. These experiments were designed to detect uptake of PI&SYT by enhancing with a ranged concentration of herb extracts.

Keywords: antimicrobial activity, flow cytometry, macrofungi, multidrug resistant

Procedia PDF Downloads 445

Authors: F. Yelles-Allam, A. A. Nouani

Abstract:

In Algeria, whey is discarded without any treatment and this causes not only pollution problem, but also a loss in nutritive components of milk. In this paper, characterization of EDAM whey, which is resulted from pasteurised mixture of cow’s milk and skim milk, and recovery of whey protein by ultrafiltration / diafiltration, was studied. The physical-chemical analysis of whey has emphasized on its pollutant and nutritive characteristics. In fact, its DBO5 and DCO are 49.33, and 127.71 gr of O2/l of whey respectively. It contains: fat (1,90±0,1 gr/l), lactose (47.32±1,57 gr/l), proteins (8.04±0,2 gr/l) and ashes (5,20±0,15 gr/l), calcium (0,48±0,04 gr/l), Na (1.104gr/l), K (1.014 gr/l), Mg (0.118 gr/l) and P (0.482 gr/l). Ultrafiltration was carried out in a polyetersulfone membrane with a cut-off of 10K. Its hydraulic intrinsic resistance and permeability are respectively: 2.041.1012 m-1 and 176,32 l/h.m2 at PTM of 1 bar. The retentate obtained at FC6, contains 16,33g/l of proteins and 70,25 g/l of dry matter. The retention rate of protein is 97, 7% and the decrease in DBO5 and DCO are at 18.875 g /l and 42.818 g/l respectively. Diafiltration performed on protein concentrates allowed the complete removal of lactose and minerals. The ultrafiltration of the whey before the disposal is an alternative for Algéria dairy industry.

Keywords: diafiltration, DBO, DCO, protein, ultrafiltration, whey

Procedia PDF Downloads 256

Authors: P. H. Le, J. Molina, S. Hirai

Abstract:

In this work, we propose the application of Japanese “Origami” art for a floating function of a small aerial vehicle such as a hexarotor. A preliminary experiment was conducted using Origami magic balls mounted under a hexarotor. This magic ball can expand and shrink using an air pump during free flying. Using this interesting and functional concept, it promises to reduce the resistance of wind as well as reduce the energy consumption when the Origami balls are deflated. This approach can be particularly useful in rescue emergency situations. Furthermore, there are many unexpected reasons that may cause the multi-rotor has to land on the surface of water due to problems with the communication between the aircraft and the ground station. In addition, a complementary experiment was designed to prove that the hexarotor can fly maintaining the stability and also, takes off and lands on the surface of water using air balloons.

Keywords: helicopter, Japanese origami ball, floating, aerial robots, rescue

Procedia PDF Downloads 387

Authors: Prashant Sharma, Jyotsna Dutta Majumdar

Abstract:

The present study concerns development of a composite thermal barrier coating consisting of a mixture of La2O3 and YSZ (with 8 wt.%, 32 wt.% and 50 wt.% 50% La2O3) by plasma spray deposition technique on a CoNiCrAlY based bond coat deposited on Inconel 718 substrate by high velocity oxy-fuel deposition (HVOF) technique. The addition of La2O3 in YSZ causes the formation of pyrochlore (La2Zr2O7) phase in the inter splats boundary along with the presence of LaYO3 phase. The coefficient of thermal expansion is significantly reduced from due to the evolution of different phases and structural defects in the sprayed coating. The activation energy for TGO growth under isothermal and cyclic oxidation was increased in the composite coating as compared to YSZ coating.

Keywords: plasma spraying, oxidation resistance, thermal barrier coating, microstructure, X-ray method

Procedia PDF Downloads 353

Authors: M. Alpaslan Koroglu

Abstract:

Fibre reinforced polymer (FRP) bridge decks have become an innovative alternative, and they have offered many advantages, and this has been increasing attention for applications in not only reinforcement of existing bridges decks but also construction of new bridges decks. The advantages of these FRP decks are; lightweight, high-strength FRP materials, corrosion resistance. However, this high strength deck is not ductile. In this study, the behaviour of hybrid FRP-steel decks are investigated. All FRP decks was analysed with the commercial package ABAQUS. In the FE model, the webs and flanges were discretised by 4 nodes shell elements. A full composite action between the steel and the FRP composite was assumed in the FE analysis because the bond-slip behaviour was unknown at that time. The performance of the proposed hybrid FRP deck panel with steel plates was evaluated by means of FE analysis.

Keywords: FRP, deck, bridge, finite element

Procedia PDF Downloads 475

Authors: Yogesh S. Patel

Abstract:

Novel polyimides were synthesized by Diels–Alder polymerization. Bisfuran was reacted with a couple of bismaleimides containing diglycidyl ether of bisphenol-A and F (epoxy) segment to obtain Diels–Alder polyadducts. Polyadducts were then aromatized and imidized (i.e. cyclized) through carboxylic and amide groups to afford polyimides. Synthesized polyadducts and polyimides were characterized by elemental analysis, spectral features, the number of average molecular weight (Mn) and thermal analysis. The ‘in situ’ glass fiber reinforced composites were prepared and characterized by mechanical, electrical, and chemical properties. These properties were compared with the other reported polyimides. All the composites showed good mechanical and electrical properties and good resistance to organic solvents and mineral acids.

Keywords: Diels-Alder reaction, bisfuran, bismaleimides, polyimide

Procedia PDF Downloads 372

Authors: Satria B. Mahathma, Asri Hendrawati

Abstract:

Background: Diabetes mellitus (DM) is a metabolic disorder syndrome characterized by chronic hyperglycemia. The number of people with diabetes rose from 108 million in 1980 to 422 million in 2014. In general, almost 90% of the prevalence of DM is type 2 DM which marked by insulin resistance and decreased receptor sensitivity. Aside from conventional antidiabetic therapy, the utilization of medicinal plants as alternative medicine has beneficial effects in diabetic patients. Flavonoid contents in radish leaves such as quercetin, pelargonidin, and kaempferol are thought to have antidiabetic activity on decreasing blood glucose levels by tricyclic nucleotide modulation of pancreatic beta cells and ameliorating insulin resistance. This study aimed to determine the effect of variant concentration of radish leaves ethanol extract on blood glucose levels in diabetic rats. Method: This study used pretest-posttest control group design by using 16 male Wistar rats which were induced type-2 diabetic by streptozotocin 60 mg/kg BW-nicotinamide 120 mg/kg BW intraperitoneally. Rats who had developed type-2 DM later divided randomly into 4 groups; negative control received placebo, positive control received glibenclamide 5 mg/kg BW/day, rats intervention I and intervention II received 100% and 50% of radish leaves ethanol extract, respectively. Treatments were administered orally for four weeks. The blood glucose levels were measured using the Enzymatic Colorimetric Test “GOD-PAP”. Data were analyzed by the dependent t-test for pretest-posttest intervention difference and one-way ANOVA followed by post hoc test to determine the significant difference of each treatment to obtain the significant data. Result: The result revealed that intervention group had lower blood glucose levels mean than control group which the lowest was intervention II group (negative control: 540,9 ± 191,7 mg/dl, positive control: 494, 97 ± 64,91 mg/dl, intervention I: 301,92 ± 165,70 mg/dl, and intervention II group: 276,1 ± 139,02 mg/dl. Intervention II group had the highest antidiabetic activity, followed by the intervention I group with the amount of decrease in blood glucose levels were -151,85 ± 77,43 mg/dl and -11,08 ± 186,62 mg/dl, however negative and positive control group didn’t have antidiabetic activity. The dependent t-test result showed there is a significant difference in decreasing blood glucose levels in the intervention II pretest-posttest intervention (p=0,03) while the other group didn’t. Data analyzed by one-way ANOVA also revealed the intervention II group significantly declined blood glucose levels compared to the negative and positive control group (p = 0,033 and p=0,032, respectively). Conclusion: There is a significant effect of radish leaves ethanol extract on blood glucose levels in streptozotocin-nicotinamide-induced diabetic rats with the optimal therapeutic effect at a concentration of 50%.

Keywords: blood glucose levels, medicinal plant, radish leaves, type-2 diabetes mellitus

Procedia PDF Downloads 135

Authors: Soledad Natalia M. Dalisay, Mylene De Guzman

Abstract:

In archipelagic countries like the Philippines, many communities thrive along coastal areas. The sea is the community members’ main source of livelihood and the site of many cultural activities. For these communities, the sea is their life and livelihood. Nevertheless, the sea also poses a hazard during the rainy season when typhoons frequent their communities. Coastal communities often encounter threats from storm surges and flooding that are common when there are typhoons. During such periods, disaster evacuation programs are implemented. However, in many instances, evacuation has been the bane of local government officials implementing such programs in their communities as resistance from community members is often encountered. Such resistance is often viewed by program implementers as due to the fact that people were hard headed and ignorant of the potential impacts of living in hazard prone areas. This paper argues that it is not for these reasons that people refused to evacuate. Drawing from data collected from fieldwork done in three sites in Central Philippines affected by super typhoon Haiyan, this study aimed to provide a contextualized understanding of peoples’ refusal to heed disaster evacuation warnings. This study utilized the multi-sited ethnography approach with in-depth episodic interviews, focus group discussions, participatory risk mapping and key informant interviews in gathering data on peoples’ experiences and insights specifically on evacuation during typhoon Haiyan. This study showed that people have priorities and considerations vital in their social lives that they are protecting in their refusal to leave their homes for pre-emptive evacuation. It is not that they are not aware of the risks when the face the hazard. It is more that they had faith in the local knowledge and strategies that they have developed since the time of their ancestors as a result of living and engaging with hazards in their areas for as long as they could remember. The study also revealed that risk in encounters with hazards was gendered. Furthermore, previous engagement with local government officials and the manner in which the pre-emptive evacuation programs were implemented had cast doubt on the value of such programs in saving their lives. Life in the designated evacuation areas can be as dangerous if not more compared with living in their coastal homes. There seems to be the impression that in the evacuation program of the government, people were being moved from hazard zones to death zones. Thus, this paper ends with several recommendations that may contribute to building more responsive evacuation programs that aim to build people’s resilience while taking into consideration the local moral world in communities in identified hazard zones.

Keywords: coastal communities, disaster evacuation, disaster risk perception, social and cultural responses to hazards

Procedia PDF Downloads 337

Authors: Ammar Boudaka, Maryam Al-Suleimani, Hajar BaOmar, Intisar Al-Lawati, Fahad Zadjali

Abstract:

Background: Hypertension is increasingly becoming a matter of medical and public health importance. The maintenance of normal blood pressure requires a balance between cardiac output and total peripheral resistance. The endothelium, through the release of vasodilating factors, plays an important role in the control of total peripheral resistance and hence blood pressure homeostasis. Transient Receptor Potential Vanilloid type 4 (TRPV4) is a mechanosensitive non-selective cation channel that is expressed on the endothelium and contributes to endothelium-mediated vasodilation. So far, no data are available about the morphological and functional status of this channel in hypertensive cases. Objectives: This study aimed to investigate whether there is any difference in the morphological and functional features of TRPV4 in the mesenteric artery of normotensive and hypertensive rats. Methods: Functional feature of TRPV4 in four experimental animal groups: young and adult Wistar-Kyoto rats (WKY-Y and WKY-A), young and adult spontaneously hypertensive rats (SHR-Y and SHR-A), was studied by adding 5 µM 4αPDD (TRPV4 agonist) to mesenteric arteries mounted in a four-chamber wire myograph and pre-contracted with 4 µM phenylephrine. The 4αPDD-induced response was investigated in the presence and absence of 1 µM HC067047 (TRPV4 antagonist), 100 µM L-NAME (nitric oxide synthase inhibitor), and endothelium. The morphological distribution of TRPV4 in the wall of rat mesenteric arteries was investigated by immunostaining. Real-time PCR was used in order to investigate mRNA expression level of TRPV4 in the mesenteric arteries of the four groups. The collected data were expressed as mean ± S.E.M. with n equal to the number of animals used (one vessel was taken from each rat). To determine the level of significance, statistical comparisons were performed using the student’s t-test and considered to be significantly different at p<0.05. Results: 4αPDD induced a relaxation response in the mesenteric arterial preparations (WKY-Y: 85.98% ± 4.18; n = 5) that was markedly inhibited by HC067047 (18.30% ± 2.86; n= 5; p<0.05), endothelium removal (19.93% ± 1.50; n = 5; p<0.05) and L-NAME (28.18% ± 3.09; n = 5; p<0.05). The 4αPDD-induced relaxation was significantly lower in SHR-Y compared to WKY-Y (SHR-Y: 70.96% ± 3.65; n = 6, WKY-Y: 85.98% ± 4.18; n = 5-6, p<0.05. Moreover, the 4αPDD-induced response was significantly lower in WKY-A than WKY-Y (WKY-A: 75.58 ± 1.30; n = 5, WKY-Y: 85.98% ± 4.18; n = 5, p<0.05). Immunostaining study showed immunofluorescent signal confined to the endothelial layer of the mesenteric arteries. The expression of TRPV4 mRNA in SHR-Y was significantly lower than in WKY-Y (SHR-Y; 0.67RU ± 0.34; n = 4, WKY-Y: 2.34RU ± 0.15; n = 4, p<0.05). Furthermore, TRPV4 mRNA expression in WKY-A was lower than its expression in WKY-Y (WKY-A: 0.62RU ± 0.37; n = 4, WKY-Y: 2.34RU ± 0.15; n = 4, p<0.05). Conclusion: Stimulation of TRPV4, which is expressed on the endothelium of rat mesenteric artery, triggers an endothelium-mediated relaxation response that markedly decreases with hypertension and growing up changes due to downregulation of TRPV4 expression.

Keywords: hypertension, endothelium, mesenteric artery, TRPV4

Procedia PDF Downloads 313

Authors: Mónica P. Cala, Juan S. Carreño, Roland J.W. Meesters

Abstract:

Recently, collection of biological fluids on special filter papers has become a popular micro-sampling technique. Especially, the dried blood spot (DBS) micro-sampling technique has gained much attention and is momently applied in various life sciences reserach areas. As a result of this popularity, DBS are not only intensively competing with the venous blood sampling method but are at this moment widely applied in numerous bioanalytical assays. In particular, in the screening of inherited metabolic diseases, pharmacokinetic modeling and in therapeutic drug monitoring. Recently, microsampling techniques were also introduced in “omics” areas, whereunder metabolomics. For a metabolic profiling study we applied micro-sampling of biological fluids (blood and plasma) from healthy controls and from women with breast cancer. From blood samples, dried blood and plasma samples were prepared by spotting 8uL sample onto pre-cutted 5-mm paper disks followed by drying of the disks for 100 minutes. Dried disks were then extracted by 100 uL of methanol. From liquid blood and plasma samples 40 uL were deproteinized with methanol followed by centrifugation and collection of supernatants. Supernatants and extracts were evaporated until dryness by nitrogen gas and residues derivated by O-methyxyamine and MSTFA. As internal standard C17:0-methylester in heptane (10 ppm) was used. Deconvolution and alignment of and full scan (m/z 50-500) MS data were done by AMDIS and SpectConnect (http://spectconnect.mit.edu) software, respectively. Statistical Data analysis was done by Principal Component Analysis (PCA) using R software. The results obtained from our preliminary study indicate that the use of dried blood/plasma on paper disks could be a powerful new tool in metabolic profiling. Many of the metabolites observed in plasma (liquid/dried) were also positively identified in whole blood samples (liquid/dried). Whole blood could be a potential substitute matrix for plasma in Metabolomic profiling studies as well also micro-sampling techniques for the collection of samples in clinical studies. It was concluded that the separation of the different sample methodologies (liquid vs. dried) as observed by PCA was due to different sample treatment protocols applied. More experiments need to be done to confirm obtained observations as well also a more rigorous validation .of these micro-sampling techniques is needed. The novelty of our approach can be found in the application of different biological fluid micro-sampling techniques for metabolic profiling.

Keywords: biofluids, breast cancer, metabolic profiling, micro-sampling

Procedia PDF Downloads 411

Authors: Aziza Barnawi

Abstract:

Background: Regular exercise reduces risk factors associated with cardiovascular diseases. Over the past decade, exercise interventions have been introduced to reduce the risk of and prevent coronary artery disease (CAD). Elevated low-density lipoproteins (LDL) contribute to the formation of atherosclerosis, its manifestations on the endothelial narrow the coronary artery and affect the endothelial function. Therefore, flow-mediated dilation (FMD) technique is used to assess the function. The results of previous studies have been inconsistent and difficult to interpret across different types of exercise programs. The relationship between exercise therapy and lipid levels has been extensively studied, and it is known to improve the lipid profile and endothelial function. However, the effectiveness of exercise in altering LDL levels and improving blood flow is controversial. Objective: This review aims to explore the evidence and quantify the impact of exercise training on LDL levels and vascular function by FMD. Methods: Electronic databases were searched PubMed, Google Scholar, Web of Science, the Cochrane Library, and EBSCO using the keywords: “low and/or moderate aerobic training”, “blood flow”, “atherosclerosis”, “LDL mediated blood flow”, “Cardiac Rehabilitation”, “low-density lipoproteins”, “flow-mediated dilation”, “endothelial function”, “brachial artery flow-mediated dilation”, “oxidized low-density lipoproteins” and “coronary artery disease”. The studies were conducted for 6 weeks or more and influenced LDL levels and/or FMD. Studies with different intensity training and endurance training in healthy or CAD individuals were included. Results: Twenty-one randomized controlled trials (RCTs) (14 FMD and 7 LDL studies) with 776 participants (605 exercise participants and 171 control participants) met eligibility criteria and were included in the systematic review. Endurance training resulted in a greater reduction in LDL levels and their subfractions and a better FMD response. Overall, the training groups showed improved physical fitness status compared with the control groups. Participants whose exercise duration was ≥150 minutes /week had significant improvement in FMD and LDL levels compared with those with <150 minutes/week.Conclusion: In conclusion, although the relationship between physical training, LDL levels, and blood flow in CAD is complex and multifaceted, there are promising results for controlling primary and secondary prevention of CAD by exercise. Exercise training, including resistance, aerobic, and interval training, is positively correlated with improved FMD. However, the small body of evidence for LDL studies (resistance and interval training) did not prove to be significantly associated with improved blood flow. Increasing evidence suggests that exercise training is a promising adjunctive therapy to improve cardiovascular health, potentially improving blood flow and contributing to the overall management of CAD.

Keywords: exercise training, low density lipoprotein, flow mediated dilation, coronary artery disease

Procedia PDF Downloads 72

Authors: Deepali Rastogi, Akanksha Rastogi

Abstract:

Comfort and safety are two essential factors in a newborn’s clothing. Natural dyes are considered safe for infant clothes because they are non-toxic and have medicinal properties. Natural dyes are sensitive to pH and may show changes in hue under different pH conditions. Infant garments face treatments different than adult clothing, for instance, exposure to infant’s saliva, milk, and urine. The present study was designed to study the suitability of natural dyes for infant clothes. Cotton fabric was dyed using fifteen natural dyes and two mordants, alum, and ferrous sulphate. The dyed samples were assessed for colour fastness to washing, rubbing, perspiration and light. In addition, fastness to milk, saliva, and urine was also tested. Simulated solutions of saliva and urine were prepared for the study. For milk, one of the commercial formulations for infants was taken and used as per the directions. A wide gamut of colours was obtained after dyeing the cotton with different natural dyes and mordants. The colour strength of all the dyed samples was determined in terms of K/S values. Most of the ferrous sulphate mordanted dyes gave higher K/S values than alum mordanted samples. The wash fastness of dyed cotton fabrics ranged from 3/4 -5. Perspiration fastness test for the samples was done in both acidic and alkaline mediums. The ratings ranged from 3-5, with most of the dyes falling in the range of 4-5. The rubbing fastness of the dyed samples was tested in dry and wet conditions. The results showed excellent rub fastness ranging between 4-5. Light fastness was found to be good to moderate. The main food for infants is milk, and this becomes one of the main agents to spot infants' garments. All dyes showed excellent fastness properties against milk with a grey scale rating of 4-5. Fastness against saliva is recommended by various eco-labels, standards, and organizations for fabrics of infants or babies. The fastness of most of the dyes was found to be satisfactory against saliva. Infant garments get frequently soiled with urine. Most of the natural dyes on cotton fabric had good to excellent fastness to simulated urine. The grey scale ratings ranged from 3/4 – 5. Thus, it can be concluded that most of the natural dyes can be successfully used for infant wear and accessories and are fast to various liquids to which infant wear are exposed. Therefore, we can surround little ones with beautiful hues from nature's garden and clothe them in natural fibres dyed with natural dyes.

Keywords: fastness properties, infant wear, mordants, natural dyes

Procedia PDF Downloads 140

Authors: Daniel Y. Abebe, Jaehyouk Choi

Abstract:

This study aims to evaluate the effective size and hysteresis characteristics of Circular Hollow Steel (CHS) damper. CHS damper is among steel dampers which are used widely for seismic energy dissipation because they are easy to install, maintain and are low cost. CHS damper dissipates seismic energy through metallic deformation due to the geometrical elasticity of circular shape and fatigue resistance around connection part. After calculating the effective size, which is found to be height to diameter ratio of √ ("3”), nonlinear FE analyses were conducted to evaluate the hysteresis characteristics. To verify the analysis simulation quasi static loading was carried out and the result was compared and satisfactory result was obtained.

Keywords: SS400 steel, circular hollow steel damper, effective size, quasi static loading, FE analysis

Procedia PDF Downloads 431

Authors: Callistus I. Iheme, Kenneth E. Asika, Emmanuel I. Ugwor, Chukwuka U. Ogbonna, Ugonna H. Uzoka, Nneamaka A. Chiegboka, Chinwe S. Alisi, Obinna S. Nwabueze, Amanda U. Ezirim, Judeanthony N. Ogbulie

Abstract:

Antimicrobial resistance (AMR) is a major threat to the global health sector. Zinc oxide nanocomposites (ZnONCs), composed of zinc oxide nanoparticles and phytochemicals from Azadirachta indica aqueous leaf extract, were assessed for their physico-chemicals, in silico and in vitro antimicrobial properties on multidrug-resistant Escherichia coli enzymes. Gas chromatography coupled with mass spectroscope (GC-MS) analysis on the ZnONCs revealed the presence of twenty volatile phytochemical compounds, among which is scoparone. Characterization of the ZnONCs was done using ultraviolet-visible spectroscopy (UV-vis), energy dispersive spectroscopy (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and x-ray diffractometer (XRD). Dehydrogenase enzyme converts colorless 2,3,5-triphenyltetrazolium chloride to the red triphenyl formazan (TPF). The rate of formazan formation in the presence of ZnONCs is proportional to the enzyme activities. The color formation is extracted and determined at 500 nm, and the percentage of enzyme activity is calculated. To determine the bioactive components of the ZnONCs, characterize their binding to enzymes, and evaluate the enzyme-ligand complex stability, respectively Discrete Fourier Transform (DFT) analysis, docking, and molecular dynamics simulations will be employed. The results showed arrays of ZnONCs nanorods with maximal absorption wavelengths of 320 nm and 350 nm and thermally stable at the temperature range of 423.77 to 889.69 ℃. In vitro study assessed the dehydrogenase inhibitory properties of the ZnONCs, conjugate of ZnONCs and ampicillin (ZnONCs-amp), the aqueous leaf extract of A. indica, and ampicillin (standard drug). The findings revealed that at the concentration of 500 μm/mL, 57.89 % of the enzyme activities were inhibited by ZnONCs compared to 33.33% and 21.05% of the standard drug (Ampicillin), and the aqueous leaf extract of the A. indica respectively. The inhibition of the enzyme activities by the ZnONCs at 500 μm/mL was further enhanced to 89.74 % by conjugating with Ampicillin. In silico study on the ZnONCs revealed scoparone as the most viable competitor of nicotinamide adenine dinucleotide (NAD⁺) for the coenzyme binding pocket on E. coli malate and histidinol dehydrogenase. From the findings, it can be concluded that the scoparone components of the nanocomposites in synergy with the zinc oxide nanoparticles inhibited E. coli malate and histidinol dehydrogenase by competitively binding to the NAD⁺ pocket and that the conjugation of the ZnONCs with ampicillin further enhanced the antimicrobial efficiency of the nanocomposite against multidrug resistant E. coli.

Keywords: antimicrobial resistance, dehydrogenase activities, E. coli, zinc oxide nanocomposites

Procedia PDF Downloads 49

Authors: Mayuri Gandhi, Nayan Agrawal, Harshita Bhatia

Abstract:

In the present work, cerium fluoride (CeF3) was selected as the host material because of its high density, fast response and high radiation resistance, efficient absorption and energy transfer by host (to activator). For the synthesis of CeF3 nanoparticles doped with Sm3+ ion, co-precipitation route was employed. Thus for optimum results, concentration dependent studies of the fluorescence of Sm3+ was carried out. The photoluminescence gave emissions in both visible as well as the NIR region and therefore it can have its application in solar cells, where it can absorb a large spectrum of energy. CeF3:Sm3+ nanoparticles were carefully incorporated in a suitable polymer matrix in order to demonstrate a variety of applications to improve the performance of the polymer materials and use it to develop high grade optoelectronic devices such as LEDs, security labelling, lasers, displays, biological imaging, etc.

Keywords: bioimaging, cerium fluoride, NIR emission, samarium

Procedia PDF Downloads 419

Authors: Nihar Ranjan, Derrick Watkins, Dev P. Arya

Abstract:

Current methods in the study of antibiotic activity of ribosome targeted antibiotics are dependent on cell based bacterial inhibition assays or various forms of ribosomal binding assays. These assays are typically independent of each other and little direct correlation between the ribosomal binding and bacterial inhibition is established with the complementary assay. We have developed novel high-throughput capable assays for ribosome targeted drug discovery. One such assay examines the compounds ability to bind to a model ribosomal RNA A-site. We have also coupled this assay to other functional orthogonal assays. Such analysis can provide valuable understanding of the relationships between two complementary drug screening methods and could be used as standard analysis to correlate the affinity of a compound for its target and the effect the compound has on a cell.

Keywords: bacterial resistance, aminoglycosides, screening, drugs

Procedia PDF Downloads 371

Authors: M. Hadji, A. Haddad, Y. Hadji

Abstract:

The effects of boronizing treatment on the friction coefficient and wear behavior of 0.35 Vf TiC- Ti3 SiC2 composite were investigated. In order to modify the surface properties of Ti3SiC2, boronizing treatment was carried out through powder pack cementation in the 1150-1350 °C temperature range. After boronizing treatment, one mixture layer, composed of TiB2 and SiC, forms on the surface of Ti3SiC2. The growth of the coating is processed by inward diffusion of Boron and obeys a linear rule. The Boronizing treatment increases the hardness of Ti3SiC2 from 6 GPa to 13 GPa. In the pin-on-disc test, i twas found that the material undergoes a steady-state coefficient of friction of around 0.8 and 0.45 in case of Ti3SiC2/Al2O3 tribocouple under 7 N load for the non treated and the boronized samples, respectively. The wear resistance of Ti3SiC2 under Al2O3 ball sliding has been significantly improved, which indicated that the boronizing treatment is a promising surface modification way of Ti3SiC2.

Keywords: MAX phase, boronizing, hardness, wear

Procedia PDF Downloads 349

Authors: Hui Li, Xiongqi Pang

Abstract:

In recent years, tight oil has become a hot spot for unconventional oil and gas exploration and development in the world. Dongpu Depression is a typical hydrocarbon-rich basin in the southwest of Bohai Bay Basin, in which tight sandstone oil and gas have been discovered in deep reservoirs, most of which are buried more than 3500m. The distribution and development characteristics of deep tight sandstone reservoirs need to be studied. The main source rocks in study area are dark mudstone and shale of the middle and lower third sub-member of Shahejie Formation. Total Organic Carbon (TOC) content of source rock is between 0.08-11.54%, generally higher than 0.6% and the value of S1+S2 is between 0.04–72.93 mg/g, generally higher than 2 mg/g. It can be evaluated as middle to fine level overall. The kerogen type of organic matter is predominantly typeⅡ1 andⅡ2. Vitrinite reflectance (Ro) is mostly greater than 0.6% indicating that the source rock entered the hydrocarbon generation threshold. The physical property of reservoir was poor, the most reservoir has a porosity lower than 12% and a permeability of less than 1×10⁻³μm. The rocks in this area showed great heterogeneity, some areas developed desserts with high porosity and permeability. According to SEM, thin section image, inclusion test and so on, the reservoir was affected by compaction and cementation during early diagenesis stage (44-31Ma). The diagenesis caused the tight reservoir in Huzhuangji, Pucheng, Weicheng Area while the porosity in Machang, Qiaokou, Wenliu Area was still over 12%. In the process of middle diagenesis phase stage A (31-17Ma), the reservoir porosity in Machang, Pucheng, Huzhuangji Area increased due to dissolution; after that the oil generation window of source rock was achieved for the first phase hydrocarbon charging (31-23Ma), formed the conventional oil deposition in Machang, Qiaokou, Wenliu, Huzhuangji Area and unconventional tight reservoir in Pucheng, Weicheng Area. Then came to stage B of middle diagenesis phase (17-7Ma), in this stage, the porosity of reservoir continued to decrease after the dissolution and led to a situation that the reservoirs were generally compacted. And since then, the second hydrocarbon filling has been processing since 7Ma. Most of the pools charged and formed in this procedure are tight sandstone oil reservoir. In conclusion, tight sandstone oil was formed in two patterns in Dongpu Depression, which could be concluded as ‘density fist then accumulation’ pattern and ‘accumulation fist next density’ pattern.

Keywords: accumulation process, diagenesis, dongpu depression, tight sandstone oil

Procedia PDF Downloads 118

Authors: M. Jahanandish, Gh. Sadeghian, M. H. Daneshvar, M. H. Jahanandish

Abstract:

The amount of resistance of a particular medium like soil to the moving objects is the interest of many areas in science. These include soil mechanics, geotechnical engineering, powder mechanics etc. Knowledge of drag force is also used for estimating the amount of momentum of fired objects like bullets. This paper focuses on measurement of drag force of sand on a cone when it moves at a low constant speed. A 30-degree apex angle cone has been used for this purpose. The study consisted of both loose and dense conditions of the soil. The applied speed has been in the range of 0.1 to 10 mm/min. The results indicate that the required force is basically independent of the cone speed; but, it is very dependent on the material densification and confining stress.

Keywords: drag force, sand, moving speed, friction angle, densification, confining stress

Procedia PDF Downloads 367

Authors: Yi-Chun Huang, Kuan-Yun Chen, Chuang-Hung Lin

Abstract:

Urban Green Belt and Blue is a part of the city landscape, it is an important constituent element of the urban environment and appearance. The Hsinchu East Gate Moat is situated in the center of the city, which not only has a wealth of historical and cultural resources, but also combines the Green Belt and the Blue Belt qualities at the same time. The Moat runs more than a thousand meters through the vital Green Belt and the Blue Belt in downtown, and each section is presented in different qualities of moat from south to north. The water area and the green belt of surroundings are presented linear and banded spread. The water body and the rich diverse river banks form an urban green belt of rich layers. The watercourse with green belt design lets users have connections with blue belts in different ways; therefore, the integration of Hsinchu East Gate and moat have become one of the unique urban landscapes in Taiwan. The study is based on the fact-finding case of Hsinchu East Gate Moat where situated in northern Taiwan, to research the impact between the SVF variation of the city and spatial sequence of Urban Green Belt and Blue landscape and visual analysis by constituent cross-section, and then comparing the influence of different leaf area index – the variable ecological factors to the degree of enclosure. We proceed to survey the landscape design of open space, to measure existing structural features of the plant canopy which contain the height of plants and branches, the crown diameter, breast-height diameter through access to diagram of Geographic Information Systems (GIS) and on-the-spot actual measurement. The north and south districts of blue green belt areas are divided 20 meters into a unit from East Gate Roundabout as the epicenter, and to set up a survey points to measure the SVF above the survey points; then we proceed to quantitative analysis from the data to calculate open landscape degree of enclosure. The results can be reference for the composition of future river landscape and the practical operation for dynamic space planning of blue and green belt landscape.

Keywords: sky view factor, degree of enclosure, spatial sequence, leaf area indices

Procedia PDF Downloads 556

Authors: Aboli Dhanavade, Shweta Bhimnath, Rutuja Jumale, Ajay Nadargi

Abstract:

Security to any of our personal thing is our most basic need. It is not possible to directly apply that standard Human-computer—interaction approaches. Important usability goal for authentication system is to support users in selecting best passwords. Users often select text-passwords that are easy to remember, but they are more open for attackers to guess. The human brain is good in remembering pictures rather than textual characters. So the best alternative is being designed that is Graphical passwords. However, Graphical passwords are still immature. Conventional password schemes are also vulnerable to Shoulder-surfing attacks, many shoulder-surfing resistant graphical passwords schemes have been proposed. Next, we have analyzed the security and usability of the proposed scheme, and show the resistance of the proposed scheme to shoulder-surfing and different accidental logins.

Keywords: shoulder-surfing, security, authentication, text-passwords

Procedia PDF Downloads 362

Authors: C. Brecher, M. Fey, F. Du Bois-Reymond, S. Neus

Abstract:

Additive manufacturing has emerged into a fast-growing section within the manufacturing technologies. Established machine tool manufacturers, such as DMG MORI, recently presented machine tools combining milling and laser welding. By this, machine tools can realize a higher degree of flexibility and a shorter production time. Still there are challenges that have to be accounted for in terms of maintaining the necessary machining accuracy - especially due to thermal effects arising through the use of high power laser processing units. To study the thermal behavior of laser-integrated machine tools, it is essential to analyze and simulate the thermal behavior of machine components, individual and assembled. This information will help to design a geometrically stable machine tool under the influence of high power laser processes. This paper presents an approach to decrease the loss of machining precision due to thermal impacts. Real effects of laser machining processes are considered and thus enable an optimized design of the machine tool, respective its components, in the early design phase. Core element of this approach is a matched FEM model considering all relevant variables arising, e.g. laser power, angle of laser beam, reflective coefficients and heat transfer coefficient. Hence, a systematic approach to obtain this matched FEM model is essential. Indicating the thermal behavior of structural components as well as predicting the laser beam path, to determine the relevant beam intensity on the structural components, there are the two constituent aspects of the method. To match the model both aspects of the method have to be combined and verified empirically. In this context, an essential machine component of a five axis machine tool, the turn-swivel table, serves as the demonstration object for the verification process. Therefore, a turn-swivel table test bench as well as an experimental set-up to measure the beam propagation were developed and are described in the paper. In addition to the empirical investigation, a simulative approach of the described types of experimental examination is presented. Concluding, it is shown that the method and a good understanding of the two core aspects, the thermo-elastic machine behavior and the laser beam path, as well as their combination helps designers to minimize the loss of precision in the early stages of the design phase.

Keywords: additive manufacturing, laser beam machining, machine tool, thermal effects

Procedia PDF Downloads 265