Search results for: vacuum packed

Authors: Dingding Chen, Kazuo Arakawa, Masakazu Uchino, Changheng Xu

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Vacuum assisted resin transfer moulding (VARTM) is a promising manufacture process for making large and complex fiber reinforced composite structures. However, the complexity of the flow of the resin in the infusion stage usually leads to nonuniform property distribution of the produced composite part. In order to control the flow of the resin, the situation of flow should be mastered. For the safety of the usage of the produced composite in practice, the understanding of the property distribution is essential. In this paper, we did some trials on monitoring the resin infusion stage and evaluation for the fiber volume fraction distribution of the VARTM produced composite using the digital image correlation methods. The results show that 3D-DIC is valid on monitoring the resin infusion stage and it is possible to use 2D-DIC to estimate the distribution of the fiber volume fraction on a FRP plate.

Keywords: digital image correlation, VARTM, FRP, fiber volume fraction

Procedia PDF Downloads 343

Authors: A. Aljohani, D. Burke, D. Clarke, M. Gormally, M. Byrne, G. Fleming

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Introduction: House Dust Mites (HDMs) are a source of allergen particles embedded in textiles and furnishings. Vacuum sampling is commonly used to recover and determine the abundance of HDMs but the efficiency of this method is less than standardized. Here, the efficiency of recovery of HDMs was evaluated from home-associated textiles using vacuum sampling protocols.Methods/Approach: Living Mites (LMs) or dead Mites (DMs) House Dust Mites (Dermatophagoides pteronyssinus: FERA, UK) were separately seeded onto the surfaces of Smooth Cotton, Denim and Fleece (25 mites/10x10cm2 squares) and left for 10 minutes before vacuuming. Fabrics were vacuumed (SKC Flite 2 pump) at a flow rate of 14 L/min for 60, 90 or 120 seconds and the number of mites retained by the filter (0.4μm x 37mm) unit was determined. Vacuuming was carried out in a linear direction (Protocol 1) or in a multidirectional pattern (Protocol 2). Additional fabrics with LMs were also frozen and then thawed, thereby euthanizing live mites (now termed EMs). Results/Findings: While there was significantly greater (p=0.000) recovery of mites (76% greater) in fabrics seeded with DMs than LMs irrespective of vacuuming protocol or fabric type, the efficiency of recovery of DMs (72%-76%) did not vary significantly between fabrics. For fabrics containing EMs, recovery was greatest for Smooth Cotton and Denim (65-73% recovered) and least for Fleece (15% recovered). There was no significant difference (p=0.99) between the recovery of mites across all three mite categories from Smooth Cotton and Denim but significantly fewer (p=0.000) mites were recovered from Fleece. Scanning Electron Microscopy images of HMD-seeded fabrics showed that live mites burrowed deeply into the Fleece weave which reduced their efficiency of recovery by vacuuming. Research Implications: Results presented here have implications for the recovery of HDMs by vacuuming and the choice of fabric to ameliorate HDM-dust sensitization.

Keywords: allergy, asthma, dead, fabric, fleece, live mites, sampling

Procedia PDF Downloads 141

Authors: Khaled Mohamed Ibrahim

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A comprehensive study on two biomaterials of NiTi and Ti-6Al-4V (Ti64) was done. Those materials were cast using vacuum arc remelting technique. As-cast structure of Ni-Ti alloy consists of NiTi matrix and some fine precipitates of Ni4Ti3. Ti-6Al-4V alloy showed a structure composed of equiaxed β grains and varied α-phase morphologies. Maximum ultimate compressive strength and reduction in height of 2042 MPa of 18%, respectively, were reported for the cast Ti64 alloy. However, minimum ultimate compressive strength of 1804 MPa and low reduction in height of 3% were obtained for the cast NiTi alloy. Wear rate of both Ni-Ti and Ti-6Al-4V alloys significantly increased at saline solution (0.9% NaCl) condition as compared to dry testing condition. Saline solution harmed the wear resistance of about 2 to 4 times compared to the dry condition. Corrosion rate of NiTi alloy at saline solution (0.9% NaCl) was (0.00038 mm/yr) is almost three times the value of Ti64 alloy (0.000171 mm/yr). The corrosion rate of Ti64 in SBF (0.00024 mm/yr) was lower than Ni-Ti (0.0003 mm/yr).

Keywords: NiTi, Ti64, vacuum casting, biomaterials

Procedia PDF Downloads 82

Authors: Oscar Corredor, Alexander Guzman, Adan Leon

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Density is a bulk physical property that indicates the quality of a petroleum fraction. It is also a useful property to estimate various physicochemical properties of fraction and petroleum fluids; however, the determination of density of extra heavy residual (EHR) fractions by standard methodologies, (ASTM D70) shows limitations for samples with higher densities than 1.0879 g/cm3. For this reason, a dilution methodology was developed in order to determinate density for those particular fractions, 87 (EHR) fractions were obtained as products of the fractionation of Colombian typical Vacuum Distillation Residual Fractions using molecular distillation (MD) and extraction with Solvent N-hexane in Supercritical Conditions (SFEF) pilot plants. The proposed methodology showed reliable results that can be demonstrated with the standard deviation of repeatability and reproducibility values of 0.0031 and 0.0061 g/ml respectively. In the same way, it was possible to determine densities in fractions EHR up to 1.1647g/cm3 and °API values obtained were ten times less than the water reference value.

Keywords: API, density, vacuum residual, molecular distillation, supercritical fluid extraction

Procedia PDF Downloads 268

Authors: Suren Chilingaryan

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We study two models describing a single two-level system coupled to two boson field modes in either a parallel or orthogonal setup. Both models may be feasible for experimental realization through Raman adiabatic driving in cavity QED. We study their ground state configurations; that is, we find the quantum precursors of the corresponding semi-classical phase transitions. We found that the ground state configurations of both models present the same critical coupling as the quantum Rabi model. Around this critical coupling, the ground state goes from the so-called normal configuration with no excitation, the qubit in the ground state and the fields in the quantum vacuum state, to a ground state with excitations, the qubit in a superposition of ground and excited state, while the fields are not in the vacuum anymore, for the first model. The second model shows a more complex ground state configuration landscape where we find the normal configuration mentioned above, two single-mode configurations, where just one of the fields and the qubit are excited, and a dual-mode configuration, where both fields and the qubit are excited.

Keywords: quantum optics, quantum phase transition, cavity QED, circuit QED

Procedia PDF Downloads 368

Authors: David A. Harness

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Natural evolution of ATP cognitive systems is to meet AI peer review standards. ATP process of axiom selection from Mizar to prove a conjecture would be further refined, as in all human and machine learning, by solving the real world problem of the proposed AI peer review challenge: Determine which conjecture forms the higher confidence level constructive proof between Standard Model of Physics SU(n) lattice gauge group operation vs. present non-standard 4D GEM EOS SU(n) lattice gauge group spatially extended operation in which the photon and electron are the first two trace angular momentum invariants of a gravitoelectromagnetic (GEM) energy momentum density tensor wavetrain integration spin-stress pressure-volume equation of state (EOS), initiated via 32 lines of Mathematica code. Resulting gravitoelectromagnetic spectrum ranges from compressive through rarefactive of the central cosmological constant vacuum energy density in units of pascals. Said self-adjoint group operation exclusively operates on the stress energy momentum tensor of the Einstein field equations, introducing quantization directly on the 4D spacetime level, essentially reformulating the Yang-Mills virtual superpositioned particle compounded lattice gauge groups quantization of the vacuum—into a single hyper-complex multi-valued GEM U(1) × SU(1,3) lattice gauge group Planck spacetime mesh quantization of the vacuum. Thus the Mizar corpus already contains all of the axioms required for relevant DeepMath premise selection and unambiguous formal natural language parsing in context deep learning.

Keywords: automated theorem proving, constructive quantum field theory, information theory, neural networks

Procedia PDF Downloads 180

Authors: Zafer Ceylan, Gülgün F.Unal Şengör, Onur Gönülal

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In this study, sous vide technology were treated with different herbs into different fish species which were caught from northern Aegean and Marmara Sea. Before samples were packaged under vacuum, herbs had been cut and added at the same ratio into the package. Samples were sliced, the weight of each sample was about 150 g, and packaged under vacuum. During the storage period at 4ºC, taste, odor, texture properties of fish samples treated with sous vide were evaluated by trained panelists. Meanwhile, the effect of different herbs on pH values of the samples was investigated. These results were correlated with sensorial results. Furthermore, the effects of different herbs on L, a, b values of fish samples treated with sous vide were evaluated by color measurement. All sensorial results indicated that the values of samples treated with herbs were higher than that of the control group. Color measurement results and pH values were found parallel with sensorial results.

Keywords: Sous vide, fish, herbs, consumer preferences, pH, color measurement

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Authors: Yafri Hazbi, Zaenal Bachruddin, Nafiatul Umami, Lies Mira Yusiati

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The objective of this study was to identify the benefits of total mixture concentrate based on tofu waste silage (TMC-TWS) as ration containing lactic acid bacteria on performance of lambs. Fifteen weaning lambs (2-3 months old) were randomly divided into two treatment groups, treatment group I (TI) was fed with TMC-TWS as ration and treatment group II (TII) was fed with TMC-TWS fresh (without silage fermentation). The performance of lambs was evaluated on day 0, 15, and 30 to have data of body weight per day. Meanwhile, blood sampling and feces were made on the 30th day to get an analysis on the blood profile (erythrocytes (mill/ml), hemoglobin (g/dL), packed cell volume (%), and leukocytes (mill/ml)) and the number of worm eggs in feces. The results of this study showed no significant difference between the effect of different feed on the blood profile (erythrocytes (mill/ml), hemoglobin (g/dL), packed cell volume (%), as well as the number of worm eggs in the feces. However the results showed significant differences if it is low (P<0.05) due to the treatment group based on sex on body weight gain per day, feed conversion rate and the number of erythrocytes.

Keywords: lambs, total mixture concentrate, silage, acid lactid bacteria, blood profile, eggs worm in feces

Procedia PDF Downloads 179

Authors: K. B. Vinay, K. G. Vismay, S. Kasturirengan, G. A. Vivek

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Cryosorption pumps are considered to be safe, quiet and ultra-high vacuum production pumps which have their application from Semiconductor industries to ITER [International Thermonuclear Experimental Reactor] units. The principle of physisorption of gases over highly porous materials like activated charcoal at cryogenic temperatures (below -1500°C) is involved in determining the pumping speed of gases like Helium, Hydrogen, Argon and Nitrogen. This paper aims at providing detailed overview of development of Cryosorption pump which is the modern ultra-high vacuum pump and characterization of different activated charcoal materials that optimizes the performance of the pump. Different grades of charcoal were tested in order to determine the pumping speed of the pump and were compared with commercially available Varian cryopanel. The results for bare panel, bare panel with adhesive, cryopanel with pellets, and cryopanel with granules were obtained and compared. The comparison showed that cryopanel adhered with small granules gave better pumping speeds than large sized pellets.

Keywords: adhesive, cryopanel, granules, pellets

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Authors: Saman Mostafazadeh-Fard, Zohrab Samani, Kenneth Suazo

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Agricultural ditch liners are used to prevent soil erosion and reduce seepage losses. This paper introduced an approach to validate a computational fluid dynamics (CFD) platform FLOW-3D code and its use to design a flow-regulating corrugated agricultural ditch liner system (Smart Ditch (SM)). Hydrodynamic and sediment transport analyses were performed on the proposed liner flow using the CFD platform FLOW-3D code. The code's hydrodynamic and scour and sediment transport models were calibrated and validated using lab data with an accuracy of 94 % and 95%, respectively. The code was then used to measure hydrodynamic parameters of sublayer turbulent intensity, kinetic energy, dissipation, and packed sediment mass normalized with respect to sublayer flow velocity. Sublayer turbulent intensity, kinetic energy, and dissipation in the SM flow were significantly higher than CR flow. An alternative corrugated liner was also designed, and sediment transport was measured and compared to SM and CR flows. Normalized packed sediment mass with respect to average sublayer flow velocity was 27.8 % lower in alternative flow compared to SM flow. CFD platform FLOW-3D code could effectively be used to design corrugated ditch liner systems and perform hydrodynamic and sediment transport analysis under various corrugation designs.

Keywords: CFD, hydrodynamic, sediment transport, ditch, liner design

Procedia PDF Downloads 123

Authors: Oluwadele Joshua Femi, Akinlabi Ebenezer Yemi, Onaopemipo Adeitan, Kazeem Bello, Anthony Ekeocha, Miraim Tawose

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This study was carried out to determine the physiological and stress index of scavenging chickens in LAFARGE (Ewekoro) and Dangote (Ibese) Cement Factories Area of Ogun State. One hundred adult scavenging chickens comprising of 25 chickens from LAFARGE, Dangote and respective adjourning communities (Imasayi and Wasimi) were used. Experimental birds were caught at night on their perch and kept in cages till the next morning. Data were collected on rectal temperature, pulse rate, and respiratory rate of the birds. Also, 5ml blood was collected through the wing vein of the chickens in each location using a sterilized needle and syringe and transported to laboratory for analysis. Significant (P<0.05) highest pulse rate (215.64 beat/minute) and respiratory rate (19.90 breaths/minute) were recorded among scavenging chickens at LAFARGE (Ewekoro) Area and the least (198.61 beat/minute and 16.93 breaths/minute, respectively) at Imasayi. There was no significant (P>0.05) difference in the rectal temperature of the birds in the study area. Significant (P<0.05) differences were also recorded in the Packed Cell Volume (PCV), Hemoglobin (Hb), White Blood Cell (WBC), Monocyte, and Glucose level of the chickens in study area with the highest (P<0.05) Packed Cell Volume (28.06%) and Haemoglobin (4.01g/dl) recorded in Ibese and the least Packed Cell Volume (22.00%) and Haemoglobin (288g/dl) in Imasayi. Highest (P<0.05) Monocyte (4.28%) and glucose (256.53g/dl) were recorded among scavenging chickens at Dangote (Ibese) while the least Monocyte (0.00%) and Glucose (194.53g/dl) was recorded among chickens at Wasimi. Highest (P<0.05) White Blood Cell (6488.89×103µl) was recorded among chickens at Ewekoro and the lowest value in Ibese (4388.44×103µl). There was no significant (P>0.05) difference in the Heterophyl, Lymphocyte, Basophyl and Heterophyl/Lymphocyte ratio of the chickens in the study Area. The study concluded that chickens reared at LAFARGE (Ewekoro) were stressed and had comprised welfare and health status compared to Dangote (Ibese) cement area and other agrarian communities. Effective environmental mitigation programme should be put in place to enhance the welfare of the scavenging chickens in LAFARGE Cement Factory Area.

Keywords: blood, chicken, poisonous substances, pack cell volume, communities

Procedia PDF Downloads 86

Authors: S Eli, DGB Kalio, BOA Altraide, P Kua, DA MacPepple, FE Okonofua

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Background: Anaemia in pregnancy is worrisome morbidity encountered by obstetricians and gynaecologist in the developing countries of the world. It is an indirect cause of maternal mortality and also a cause of perinatal mortality. Aim: The study aimed to ascertain the prevalence of anaemia amongst antenatal clinic (ANC) attendees at booking at The Rivers State University Teaching Hospital (RSUTH), Port Harcourt, Rivers State, Nigeria. Method: The method was a cross-sectional study of ANC attendees at booking at RSUTH. The cut-off for anaemia by the WHO used for this study was packed cell volume (PCV) less than 33%. Simple randomized sampling method was used. Information was analyzed using SPSS version 25. Result: A total of 500 questionnaires were distributed, and 488 questionnaires retrieved. The mean age was of the ANC attendees was 31.44 years, and the modal parity was 0. Three hundred and fifty-seven (73.2%) of the respondents had a tertiary level of education, 126(25.8%) had a secondary level of education while 5 (1%) of the respondents had a primary level of education. Five (1%) of the respondents did not volunteer their educational status. The modal packed cell volume was 32%. Three hundred and eighty-two (78.3%) of the ANC attendees had PCV level less than 33% compared to 106 (21.7%) who had PCV equal or greater than 33%. Conclusion: The study revealed that the prevalence of anaemia in pregnancy amongst ANC attendees at the RSUTH was high, representing 73.3% of the subjects. Anaemia was common amongst multiparas (38.5%). Malaria prophylaxis, as well as encouraging pregnant women to be compliant with their routine antenatal drugs as well as counseling on the right diet, cannot be overemphasized during pregnancy. In addition, women should use family planning for child spacing for them to recover from previous pregnancies.

Keywords: anaemia, ANC attendees, Nigeria, prevalence

Procedia PDF Downloads 120

Authors: Seyed-Ahmad Shahidi, Salemeh Kazemzadeh, Mehdi Sharifi Soltani, Azade Ghorbani-HasanSaraei

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The kinetics of colour changes of American Pokeweed extract, due to concentration by various heating methods was studied. Three different heating/evaporation processes were employed for production of American Pokeweed extract concentrate. The American Pokeweed extract was concentrated to a final 40 °Brix from an initial °Brix of 4 by microwave heating, rotary vacuum evaporator and evaporating at atmospheric pressure. The final American Pokeweed extract concentration of 40 °Brix was achieved in 188, 216 and 320 min by using microwave, rotary vacuum and atmospheric heating processes, respectively. The colour change during concentration processes was investigated. Total colour differences, Hunter L, a and b parameters were used to estimate the extent of colour loss. All Hunter colour parameters decreased with time. The zero-order, first-order and a combined kinetics model were applied to the changes in colour parameters. All models were found to describe the L, a and b-data adequately. Results indicated that variation in TCD followed both first-order and combined kinetics models. This model implied that the colour formation and pigment destruction occurred during concentration processes of American Pokeweed extract.

Keywords: American pokeweed, colour, concentration, kinetics

Procedia PDF Downloads 499

Authors: Azade Ghorbani-HasanSaraei, Seyed-Ahmad Shahidi, Sakineh Alizadeh, Adeleh Maghsoudlou

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Improvement of color, as a quality attribute of Plum Concentrate, has been made possible by the increase in knowledge of kinetic of color change. Three different heating/evaporation processes were employed for the production of pPlum juice concentrate. The Plum juice was concentrated to a final 55 °Bx from an initial °Bx of 15 by microwave heating, rotary vacuum evaporator and evaporating at atmospheric pressure. The final Plum juice concentration of 55 °Bx was achieved in 17, 24 and 57 min by using the microwave, rotary vacuum and atmospheric heating processes, respectively. The colour change during concentration processes was investigated. Total colour differences, Hunter L, a and b parameters were used to estimate the extent of colour loss. All Hunter colour parameters decreased with time. The zero-order, first-order and a combined kinetics model were applied to the changes in colour parameters. Results indicated that variation in TCD followed both first-order and combined kinetics models, and parameters L, a and b followed only combined model. This model implied that the colour formation and pigment destruction occurred during concentration processes of plum juice.

Keywords: colour, kinetics, concentration, plum juice

Procedia PDF Downloads 521

Authors: H. K. Shivanand, Ranjith R. Hombal, Paraveej Shirahatti, Gujjalla Anil Babu, S. ShivaPrakash

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When it comes to the selection of materials the knowledge of materials science plays a vital role in selection and enhancements of materials properties. In the world of material science a composite material has the significant role based on its application. The composite materials are those in which two or more components having different physical and chemical properties are combined to create a new enhanced property substance. In this study three different materials (Kenaf, Kevlar and Graphene) been chosen based on their properties and a composite material is developed with help of vacuum bagging process. The fibers (Kenaf and Kevlar) and Resin(vinyl ester) ratio was maintained at 70:30 during the process and 0.5% 1% and 1.5% of Graphene was added during fabrication process. The material was machined to thedimension ofASTM standards(300×300mm and thickness 3mm)with help of water jet cutting machine. The composite materials were tested for Mechanical properties such as Interlaminar shear strength(ILSS) and Flexural strength. It is found that there is significant increase in material properties in the developed composite material.

Keywords: Kevlar, Kenaf, graphene, vacuum bagging process, Interlaminar shear strength test, flexural test

Procedia PDF Downloads 95

Authors: E. Yazıcı, H. Sundu, E. Veli Veliev

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In order to understand the nature of strong interactions and QCD vacuum, investigation of the meson coupling constants have an important role. The knowledge on the temperature dependence of the form factors is very important for the interpretation of heavy-ion collision experiments. Also, more accurate determination of these coupling constants plays a crucial role in understanding of the hadronic decays. With the increasing of CM energies of the experiments, researches on meson interactions have become one of the more interesting problems of hadronic physics. In this study, we analyze the temperature dependence of the strong form factor of the BcBcJ/ψ vertex using the three point QCD sum rules method. Here, we assume that with replacing the vacuum condensates and also the continuum threshold by their thermal version, the sum rules for the observables remain valid. In calculations, we take into account the additional operators, which appear in the Wilson expansion at finite temperature. We also investigated the momentum dependence of the form factor at T = 0, fit it into an analytic function, and extrapolate into the deep time-like region in order to obtain a strong coupling constant of the vertex. Our results are consistent with the results existing in the literature.

Keywords: QCD sum rules, thermal QCD, heavy mesons, strong coupling constants

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Authors: Arburim Iseni, Afrim Aliti, Nagri Rexhepi

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The blood feud or blood-taking is a social obligation to commit murder in order to salvage honor questioned by an earlier murder or moral humiliation. This social obligation is still preserved as a stub among Albanians when honor is violated. By the term honor are understood many things, such as honor to the family, house, guest, property, etc. Many Albanian family members are forced to stay locked up at home because of the blood killing, whereas other families abandon their houses and migrate to other places. Nonetheless, Albanians maintain close ties with their extended families, clans, and tribes and thus chances are high that the violence can beget more violence and without reconciliation of the blood these families will always be endangered. One of the reasons for the pervasiveness of the blood feud is the poor social conditions, political imbroglio and the power vacuum which comes from the corrupted and judiciary system of the state. Contrary to this, Albanian blood feud is not a phenomenon present only to the Albanians, but it also takes place in some other cultures and nations, such as: Chechens, Montenegrins, Serbians, and lately more radical one is between Amman and Israel who are at constant feud.

Keywords: honor, blood feud, reconciliation, power vacuum, poor social conditions, political imbroglio

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Authors: T. Z. Butt, T. A. Tabish, K. Anjum, H. Hafeez

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A study of martensitic stainless steel surgical grade AISI 420A produced in Japan was carried out in this research work. The sample was already annealed at about 898˚C. The sample were subjected to chemical analysis, hardness, tensile and metallographic tests. These tests were performed on as received annealed and heat treated samples. In the annealed condition the sample showed 0HRC. However, on tensile testing, in annealed condition the sample showed maximum elongation. The heat treatment is carried out in vacuum furnace within temperature range 980-1035°C. The quenching of samples was carried out using liquid nitrogen. After hardening, the samples were subjected to tempering, which was carried out in vacuum tempering furnace at a temperature of 220˚C. The hardened samples were subjected to hardness and tensile testing. In hardness testing, the samples showed maximum hardness values. In tensile testing the sample showed minimum elongation. The sample in annealed state showed coarse plates of martensite structure. Therefore, the studied steels can be used as biomaterials.

Keywords: biomaterials, martensitic steel, microsrtucture, tensile testing, hardening, tempering, bioinstrumentation

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Authors: Rajesh Panda, Jimi Tjong, Sanjay K. Nayak, Mohini M. Sain

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The aim of this manuscript was to evaluate the effect of chemical treatment of sisal fibre on the mechanical and viscoelastic properties of bio based epoxy/fibre composites. The composite samples were manufactured through a vacuum infusion process by adding alkyl phenols from cashew nutshell liquid (CSNL). Changes in the chemical structure of the sisal fibres resulting from the treatments were analyzed by Fourier transform infrared spectroscopy (FTIR). Both alkali and silane treatments produced enhancements in the mechanical properties of sisal fibre bundles. The alkali treatment, when combined with the silane treatment, the mechanical properties of epoxy composites notably improved (13%) in comparison to untreated sisal fibre reinforced composites.This was attributed to an enhanced fibre/matrix interface. The incorporation of CSNL into the sisal/epoxy composite enhanced the fibre-matrix interfacial properties because of the addition of -OH groups to the epoxy matrix. The incorporation of sisal fibre imparts stiffness to the epoxy matrix.

Keywords: phenalkamine, sisal fiber, vacuum infusion, cashew nutshell liquid, cashew nutshell liquid (CSNL)

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Authors: Ju Young Kim, Mohammad Zahirul Islam, Mahmuda Akter Mele, Su Jeong Han, Hyuk Sung Yoon, In-Lee Choi, Ho-Min Kang

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Strawberry and tomato fruits were harvested at the red ripens maturity stage in the Republic of Korea. The fruits were dipped in fungi solution and afterwards were sterilized with sodium hypochlorite (NaOCl) and chlorine dioxide (ClO2) gas. Some fruits were dipped in 150μL/L NaOCl solution for 10 minutes, and others were treated with 5μL/L ClO2 gas for 12 hours and packed with 20,000 cc OTR (oxygen transmission rate) film, the rest were packed in 10,000 cc OTR film inserted with 5μL/L ClO2 gas. 5μL/L ClO2 gas insert treatment showed the lowest carbon dioxide and ethylene, and the highest oxygen concentration was on the final storage day (15th day) in both strawberry and tomato fruits. Tomato fruits showed the lowest fresh weight loss in 5μL/L ClO2 gas insert treatment. The visual quality as well as shelf life showed the highest in 5μL/L ClO2 gas insert treatment of both strawberry and tomato fruits. In addition, the fungal incidence of strawberry and tomato fruits were the most suppressed in 5μL/L ClO2 gas insert treatment. 5μL/L ClO2 gas insert treatment showed higher firmness and soluble solids in both strawberry and tomato fruits. So, 5μL/L ClO2 gas insert treatment may be useful to prevent the fungal incidence as well as retaining the postharvest quality, and increase the shelf life of strawberry and tomato fruits for long term storage. This study was supported by Export Promotion Technology Development Program (314027-03), IPET, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea.

Keywords: chlorine dioxide, ethylene, fungi, sodium hypochlorite

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Authors: Adolfo Martucci, Iulian Mihai

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By means of the expansion through a Conical Nozzle and the low pressure inside the Test Chamber, a large hypersonic stable flow takes place for a duration of up to 30 minutes. Downstream the Test Chamber, the diffuser has the function of reducing the flow velocity to subsonic values, and as a consequence, the temperature increases again. In order to cool down the flow, a heat exchanger is present at the end of the diffuser. The Vacuum System generates the necessary vacuum conditions for the correct hypersonic flow generation, and the DeNOx system, which follows the Vacuum System, reduces the nitrogen oxide concentrations created inside the plasma flow behind the limits imposed by Italian law. This very large, powerful, and complex facility allows researchers and engineers to reproduce entire re-entry trajectories of space vehicles into the atmosphere. One of the most important parameters for a hypersonic flowfield representative of re-entry conditions is the specific total enthalpy. This is the whole energy content of the fluid, and it represents how severe could be the conditions around a spacecraft re-entering from a space mission or, in our case, inside a hypersonic wind tunnel. It is possible to reach very high values of enthalpy (up to 45 MJ/kg) that, together with the large allowable size of the models, represent huge possibilities for making on-ground experiments regarding the atmospheric re-entry field. The maximum nozzle exit section diameter is 1950 mm, where values of Mach number very much higher than 1 can be reached. The specific total enthalpy is evaluated by means of a number of measurements, each of them concurring with its value and its uncertainty. The scope of the present paper is the evaluation of the sensibility of the uncertainty of the specific total enthalpy versus all the parameters and measurements involved. The sensors that, if improved, could give the highest advantages have so been individuated. Several simulations in Python with the METAS library and by means of Monte Carlo simulations are presented together with the obtained results and discussions about them.

Keywords: hypersonic, uncertainty, enthalpy, simulations

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Authors: Jaehyug Lee, Tae-Ho Song

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Vacuum insulation panel (VIP) can achieve very low thermal conductivity by evacuating its inner space. Heat transfer in the core materials of highly-evacuated VIP occurs by conduction through the solid structure and radiation through the pore. The effect of various scattering modes in combined conduction-radiation in VIP is investigated through numerical analysis. The discrete ordinates interpolation method (DOIM) incorporated with the commercial code FLUENT® is employed. It is found that backward scattering is more effective in reducing the total heat transfer while isotropic scattering is almost identical with pure absorbing/emitting case of the same optical thickness. For a purely scattering medium, the results agree well with additive solution with diffusion approximation, while a modified term is added in the effect of optical thickness to backward scattering is employed. For other scattering phase functions, it is also confirmed that backwardly scattering phase function gives a lower effective thermal conductivity. Thus, the materials with backward scattering properties, with radiation shields are desirable to lower the thermal conductivity of VIPs.

Keywords: combined conduction and radiation, discrete ordinates interpolation method, scattering phase function, vacuum insulation panel

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Authors: Breanna Macumber, Victor A. Huayamave, Emir A. Vela, Wangdo Kim, Tamara T. Chamber, Esteban Centeno

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Spina bifida is a type of neural tube defect that affects the nervous system and can lead to problems such as total leg paralysis. Treatment requires physical therapy and rehabilitation. Robotic exoskeletons have been used for rehabilitation to train muscle movement and assist in injury recovery; however, current models focus on the adult populations and not on the infant population. The proposed framework aims to couple a musculoskeletal infant model with a robotic exoskeleton using vacuum-powered artificial muscles to provide rehabilitation to infants affected by spina bifida. The study that drove the input values for the robotic exoskeleton used motion capture technology to collect data from the spontaneous kicking movement of a 2.4-month-old infant lying supine. OpenSim was used to develop the musculoskeletal model, and Inverse kinematics was used to estimate hip joint angles. A total of 4 kicks (A, B, C, D) were selected, and the selection was based on range, transient response, and stable response. Kicks had at least 5° of range of motion with a smooth transient response and a stable period. The robotic exoskeleton used a Vacuum-Powered Artificial Muscle (VPAM) the structure comprised of cells that were clipped in a collapsed state and unclipped when desired to simulate infant’s age. The artificial muscle works with vacuum pressure. When air is removed, the muscle contracts and when air is added, the muscle relaxes. Bench testing was performed using a 6-month-old infant mannequin. The previously developed exoskeleton worked really well with controlled ranges of motion and frequencies, which are typical of rehabilitation protocols for infants suffering with spina bifida. However, the random kicking motion in this study contained high frequency kicks and was not able to accurately replicate all the investigated kicks. Kick 'A' had a greater error when compared to the other kicks. This study has the potential to advance the infant rehabilitation field.

Keywords: musculoskeletal modeling, soft robotics, rehabilitation, pediatrics

Procedia PDF Downloads 120

Authors: Breanna Macumber, Victor A. Huayamave, Emir A. Vela, Wangdo Kim, Tamara T. Chamber, Esteban Centeno

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Spina bifida is a type of neural tube defect that affects the nervous system and can lead to problems such as total leg paralysis. Treatment requires physical therapy and rehabilitation. Robotic exoskeletons have been used for rehabilitation to train muscle movement and assist in injury recovery; however, current models focus on the adult populations and not on the infant population. The proposed framework aims to couple a musculoskeletal infant model with a robotic exoskeleton using vacuum-powered artificial muscles to provide rehabilitation to infants affected by spina bifida. The study that drove the input values for the robotic exoskeleton used motion capture technology to collect data from the spontaneous kicking movement of a 2.4-month-old infant lying supine. OpenSim was used to develop the musculoskeletal model, and Inverse kinematics was used to estimate hip joint angles. A total of 4 kicks (A, B, C, D) were selected, and the selection was based on range, transient response, and stable response. Kicks had at least 5° of range of motion with a smooth transient response and a stable period. The robotic exoskeleton used a Vacuum-Powered Artificial Muscle (VPAM) the structure comprised of cells that were clipped in a collapsed state and unclipped when desired to simulate infant’s age. The artificial muscle works with vacuum pressure. When air is removed, the muscle contracts and when air is added, the muscle relaxes. Bench testing was performed using a 6-month-old infant mannequin. The previously developed exoskeleton worked really well with controlled ranges of motion and frequencies, which are typical of rehabilitation protocols for infants suffering with spina bifida. However, the random kicking motion in this study contained high frequency kicks and was not able to accurately replicate all the investigated kicks. Kick 'A' had a greater error when compared to the other kicks. This study has the potential to advance the infant rehabilitation field.

Keywords: musculoskeletal modeling, soft robotics, rehabilitation, pediatrics

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Authors: Uwonkunda Jeanne, J. Godwin Prem Singh, Anjaneyalu Subbiah

Abstract:

HIV/AIDS is known to affect an individual not only physically but also mentally, socially, and financially. It is a syndrome that builds a vacuum in a person affecting his/her life as a whole.

Keywords: People living with HIV, social dysfunction, stigma, and Social support.

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Authors: A. M. Aminazad, A. M. Hadian, F. Ghasimakbari

Abstract:

DHP (Deoxidized High Phosphorus )copper is widely used in various heat transfer units such as, air conditioners refrigerators, evaporators and condensers. Copper sheets and tubes (ISODHP) were brazed with four different brazing alloys. Corrosion resistances of the joints were examined by polarization and salt spray tests. The selected fillers consisted of three silver-based brazing alloys (hard solder); AWS-BCu5 BAg8, DINLAg30, and a copper-based filler AWS BCuP2. All the joints were brazed utilizing four different brazing processes including furnace brazing under argon, vacuum, air atmosphere and torch brazing. All of the fillers were used with and without flux. The microstructure of the brazed sheets was examined using both optical and scanning electron microscope (SEM). Hardness and leak tests were carried out on all the brazed tubes. In all three silver brazing alloys selective and galvanic corrosion were observed in filler metals, but in copper phosphor alloys the copper adjacent to the joints were noticeably corroded by pitting method. Microstructure of damaged area showed selective attack of copper lamellae as well. Interfacial attack was observed along boundaries as well as copper attack within the filler metal itself. It was found that the samples brazed with BAg5 filler metal using vacuum furnace show a higher resistance to corrosion. They also have a good ductility in the brazed zone.

Keywords: copper, brazing, corrosion, filler metal

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Authors: Marcin Dębowski, Mirosław Krzemieniewski, Marcin Zieliński

Abstract:

This publication presents a device designed to depolymerise and structurally change organic substrate, for use in agricultural biogas plants or sewage treatment plants. The presented device consists of a heated tank equipped with an inlet valve for the crude substrate and an outlet valve for the treated substrate. The system also includes a gas conduit, which is at its tip equipped with a high-pressure solenoid valve and a vacuum relief solenoid valve. A conduit behind the high-pressure solenoid valve connects to the vacuum tank equipped with the outlet valve. The substrate introduced into the device is exposed to agents such as high temperature and cavitation produced by abrupt, short-term reduction of pressure within the heated tank. The combined effect of these processes is substrate destruction rate increase of about 20% when compared to using high temperature alone, and about 30% when compared to utilizing only cavitation. Energy consumption is greatly reduced, as the pressure increase is generated by heating the substrate. Thus, there is a 18% reduction of energy consumption when compared to a device designed to destroy substrate through high temperature alone, and a 35% reduction if compared to using cavitation as the only means of destruction.

Keywords: thermal depolymerisation, organic substrate, biogas, pre-treatment

Procedia PDF Downloads 566

Authors: Alok Srivastava, Vidit Gupta, Aparna Singh, Chandra Sekher Yerramalli

Abstract:

Carbon-fiber epoxy composites show extremely high modulus and strength in the uniaxial direction. However, they are prone to fail under low load in transverse direction due to the weak nature of the interface between the carbon-fiber and epoxy. In the current study, we have coated graphene nano-platelets (GNPs) on the carbon-fibers in an attempt to strengthen the interface/interphase between the fiber and the matrix. Vacuum Assisted Resin Transfer Moulding (VARTM) has been used to make the laminates of eight cross-woven fabrics. Tensile, flexural and fracture toughness tests have been performed on pristine carbon-fiber composite (P-CF), GNP coated carbon-fiber composite (GNP-CF) and functionalized-GNP coated carbon-fiber composite (F-GNP-CF). The tensile strength and flexural strength values are pretty similar for P-CF and GNP-CF. The micro-structural examination of the GNP coated carbon-fibers, as well as the fracture surfaces, have been carried out using scanning electron microscopy (SEM). The micrographs reveal the deposition of GNPs onto the carbon fibers in transverse and longitudinal direction. Fracture surfaces show the debonding and pull outs of the carbon fibers in P-CF and GNP-CF samples.

Keywords: carbon fiber, graphene nanoplatelets, strength, VARTM, Vacuum Assisted Resin Transfer Moulding

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Authors: Ruth Lorivi, Jianzheng Li, John J. Ambuchi, Kaiwen Deng

Abstract:

Nitrogen removal from wastewater is accomplished by nitrification and denitrification processes. Successful denitrification requires carbon, therefore, if placed after biochemical oxygen demand (BOD) and nitrification process, a carbon source has to be re-introduced into the water. To avoid adding a carbon source, denitrification is usually placed before BOD and nitrification processes. This process however involves recycling the nitrified effluent. In this study wood chips were used as internal carbon source which enabled placement of denitrification after BOD and nitrification process without effluent recycling. To investigate the efficiency of a wood packed aerobic-anaerobic baffled reactor on carbon and nutrients removal from domestic wastewater, a three compartment baffled reactor was presented. Each of the three compartments was packed with 329 g wood chips 1x1cm acting as an internal carbon source for denitrification. The proposed mode of operation was aerobic-anoxic-anaerobic (OAA) with no effluent recycling. The operating temperature, hydraulic retention time (HRT), dissolved oxygen (DO) and pH were 24 ± 2 ℃, 24 h, less than 4 mg/L and 7 ± 1 respectively. The removal efficiencies of chemical oxygen demand (COD), ammonia nitrogen (NH₄⁺-N) and total nitrogen (TN) attained was 99, 87 and 83% respectively. TN removal rate was limited by nitrification as 97% of ammonia converted into nitrate and nitrite was denitrified. These results show that application of wood chips in wastewater treatment processes is an efficient internal carbon source. 

Keywords: aerobic-anaerobic baffled reactor, denitrification, nitrification, wood chip

Procedia PDF Downloads 298

Authors: Tekle Olbamo, Tegegn Tesfaye, Dikaso Unbushe, Belete Jorga

Abstract:

Bovine trypanosomosis is a haemoprotozoan parasitic disease, mostly transmitted by the tsetse fly (Glossina species) and poses significant losses to the livestock industry in pastoral and agro-pastoral areas. Therefore, the current study was aimed to determine the prevalence of bovine trypanosomosis and its vectorial density in some selected tsetse suppression and non-tsetse suppression areas of South Omo Zonefrom December 2018- November 2019. Dark phase contrast buffy coat, hematocrit techniques, and thin blood smear method were used for determination of prevalence and packed cell volume of trypanosomosis infection, respectively. For entomological investigation, 96 NGU traps were deployed (64 traps in tsetse suppression areas, 32 traps in tsetse non-suppression areas) in vector breeding areas. The overall prevalence of bovine trypanosomosis was 11.05% (142/1284), and overall seasonal prevalence of disease was 14.33% (92/642) and 7.78% (50/642) for dry and wet seasons, respectively. There was a statistically significant difference (P <0.05) in disease prevalence between the two seasons. Trypanosomacongolensewas the dominant parasite species; 80% and 71.64%, followed by Trypanosomavivax. Overall mean packed cell volume indicated parasitaemic animals (23.57±3.13) had significantly lower PCV than aparasitaemic animals (27.80±4.95), and animals examined during dry season (26.22±4.37) had lower mean PCV than animals examined during wet season with the significant association. Entomological study result revealed a total of 2.64 F/T/D and 2.03 F/T/D respectively from tsetse suppression areas and tsetse non-suppression areas during dry season and 0.42 F/T/D and 0.56 F/T/D during the wet season. Glossinapallidipes was the only cyclical vectors collected and identified from current study areas along with numerous mechanical vectors of genus Tabanus, Stomoxys, and Haematopota. Therefore integrated and safe control and prevention effort should be engaged to uphold cattle production and productivity in the area.

Keywords: bovine trypanosomiasis, South Omo, tsetse fly density, epidemiological study

Procedia PDF Downloads 163