Search results for: thermal protective clothing

Authors: J. K. Chawla, S. K. Jain, M. K. Mishra

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Ion-acoustic double layers have been studied in magnetized plasma. The modified Korteweg-de Vries (m-KdV) equation using reductive perturbation method is derived. It is found that for the selected set of parameters, the system supports rarefactive double layers depending upon the value of nonthermal parameters. It is also found that the magnetization affects only the width of the double layer. For a given set of parameter values, increases in the magnetization and the obliqueness angle (θ) between wave vector and magnetic field, affect the width of the double layers, however the amplitude of the double layers have no effect. An increase in the values of nonthermal parameter decreases the amplitude of the rarefactive double layer. The effect of the ion temperature ratio on the amplitude and width of the double layers are also discussed in detail.

Keywords: ion-acoustic double layers, magnetized electronegative plasma, reductive perturbation method, the modified Korteweg-de Vries (KdV) equation

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Authors: Govindan Sudha, Mathumitha Subramaniam, Alamelu Govindasamy, Sasikala Gunasekaran

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The aim of this study was to investigate the protective effect of Hypsizygus ulmarius polysaccharides (HUP) on reducing oxidative stress, cognitive impairment and neurotoxicity in D-galactose induced aging mice. Mice were subcutaneously injected with D-galactose (150 mg/kg per day) for 6 weeks and were administered HUP simultaneously. Aged mice receiving vitamin E (100 mg/kg) served as positive control. Chronic administration of D-galactose significantly impaired cognitive performance oxidative defence and mitochondrial enzymes activities as compared to control group. The results showed that HUP (200 and 400 mg/kg) treatment significantly improved the learning and memory ability in Morris water maze test. Biochemical examination revealed that HUP significantly increased the decreased activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), mitochondrial enzymes-NADH dehydrogenase, malate dehydrogenase (MDH), isocitrate dehydrogenase (ICDH), Na+K+, Ca2+, Mg2+ATPase activities, elevated the lowered total anti-oxidation capability (TAOC), glutathione (GSH), vitamin C and decreased the raised acetylcholinesterase (AChE) activities, malondialdehyde (MDA), hydroperoxide (HPO), protein carbonyls (PCO), advanced oxidation protein products (AOPP) levels in brain of aging mice induced by D-gal in a dose-dependent manner. In conclusion, present study highlights the potential role of HUP against D-galactose induced cognitive impairment, biochemical and mitochondrial dysfunction in mice. In vitro studies on the effect of HUP on scavenging DPPH, ABTS, DMPD, OH radicals, reducing power, B-carotene bleaching and lipid peroxidation inhibition confirmed the free radical scavenging and antioxidant activity of HUP. The results suggest that HUP possesses anti-aging efficacy and may have potential in treatment of neurodegenerative diseases.

Keywords: aging, antioxidants, mushroom, neurotoxicity

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Authors: Ben Main Piotr Ozieranski

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State government spending on pharmaceuticals stands at 1 trillion USD globally, promoting criticism of the pharmaceutical industry's monetization of drug efficacy, product cost overvaluation, and health injustice. This paper elucidates the mechanisms behind a state-institutional response to this problem through the sociological lens of the strategic relational approach to state power. To do so, 30 expert interviews, legal and policy documents are drawn on to explain how state elites in New Zealand have successfully contested a 30-year “pharmaceutical spending containment policy”. Proceeding from Jessop's notion of strategic “selectivity”, encompassing analyses of the enabling features of state actors' ability to harness state structures, a theoretical explanation is advanced. First, a strategic context is described that consists of dynamics around pharmaceutical dealmaking between the state bureaucracy, pharmaceutical pricing strategies (and their effects), and the industry. Centrally, the pricing strategy of "bundling" -deals for packages of drugs that combine older and newer patented products- reflect how state managers have instigated an “incentivization game” that is played by state and industry actors, including HTA professionals, over pharmaceutical products (both current and in development). Second, a protective context is described that is comprised of successive legislative-judicial responses to the strategic context and characterized by the regulation and the societalisation of commercial law. Third, within the policy, the achievement of increased pharmaceutical coverage (pharmaceutical “mix”) alongside contained spending is conceptualized as a state defence of a "social profit". As such, in contrast to scholarly expectations that political and economic cultures of neo-liberalism drive pharmaceutical policy-making processes, New Zealand's state elites' approach is shown to be antipathetic to neo-liberals within an overall capitalist economy. The paper contributes an analysis of state pricing strategies and how they are embedded in state regulatory structures. Additionally, through an analysis of the interconnections of state power and pharmaceutical value Abrahams's neo-liberal corporate bias model for pharmaceutical policy analysis is problematised.

Keywords: pharmaceutical governance, pharmaceutical bureaucracy, pricing strategies, state power, value theory

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Authors: Xiaoxin Ye, Guoyi Tang

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The effect of electropulsing ultrasonic shock (EUS) on the surface hardening and microstructure of Ti6Al4V alloy was studied. It was found that electropulsing improved the microhardness dramatically both in the influential depth and maximum value, compared with the only ultrasonic-shocked sample. It’s indicated that refined surface layer with nanocrystalline and improved microhardness were obtained on account of surface severe plastic deformation, dynamic recrystallization (DRX) and phase change, which was implemented at relative low temperature and high strain rate/capacity due to the coupling of the thermal and athermal effects of EUS. It’s different from conventional experiments and theory. It’s discussed that the positive contributions of EPT in the thermodynamics and kinetics of microstructure and properties change were attributed to the reduction of nucleation energy barrier and acceleration of atomic diffusion. Therefore, it’s supposed that EUS is an energy-saving and high-efficiency method of surface treatment technique with the help of high-energy electropulses, which is promising in cost reduction of the surface engineering and energy management.

Keywords: titanium alloys, electropulsing, ultrasonic shock, microhardness, nanocrystalline

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Authors: Raksit Nanthatanti, Jarruwat Charoensuk, S. Hirai, Manop Masomtop

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In this study, the effect of channel geometry and operating circumstances on a liquid cooling plate for Lithium-ion Battery modules has been investigated Inlet temperature, water velocity, and channel count were the main factors. According to the passage, enhancing the number of cooling channels[2,3,4,6channelperbases] will affect water flow distribution caused by varying the velocity inlet inside the cooling block[0.5,1.0,1.5,2.0 m/sec] and intake temperatures[25,30,35,40oC], The findings indicate that the battery’s temperature drops as the number of channels increases. The maximum battery's operating temperature [45 oC] rises, but ∆t is needed to be less than 5 oC [v≤1m/sec]. Maximum temperature and local temperature difference of the battery change significantly with the change of the velocity inlet in the cooling channel and its thermal conductivity. The results of the simulation will help to increase cooling efficiency on the cooling system for Li-ion Battery based on a Mini channel in a liquid-cooling configuration

Keywords: cooling efficiency, channel count, lithium-ion battery, operating

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Authors: Ilana Margalith, Adaya Meirowitz, Sigalit Cohavi

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Violence against health professionals by patients and their families have recently become a disturbing phenomenon worldwide, exacting psychological as well as economic tolls. Health workplaces in Israel (e.g. hospitals and H.M.O clinics) provide workshops for their employees, supplying them with coping strategies. However, these workshops do not focus on nursing students, who are also subjected to this violence. Their learning environment is no longer as protective as it used to be. Furthermore, coping with violence was not part of the curriculum for Israeli nursing students. Thus, based on human aggression theories which depict the pivotal role of the professional's correct response in preventing the onset of an aggressive response or the escalation of violence, a workshop was developed for undergraduate nursing students at the Clalit Nursing Academy, Rabin Campus (Dina), Israel. The workshop aimed at reducing students' anxiety vis a vis the aggressive patient or family in addition to strengthening their ability to cope with such situations. The students practiced interpersonal skills, especially relevant to early detection of potential violence, as well as ‘a correct response’ reaction to the violence, thus developing the necessary steps to be implemented when encountering violence in the workplace. In order to assess the efficiency of the workshop, the participants filled out a questionnaire comprising knowledge and self-efficacy scales. Moreover, the replies of the 23 participants in this workshop were compared with those of 24 students who attended a standard course on interpersonal communication. Students' self-efficacy and knowledge were measured in both groups before and after the course. A statistically significant interaction was found between group (workshop/standard course) and time (before/after) as to the influence on students' self-efficacy (p=0.004) and knowledge (p=0.007). Nursing students, who participated in this ‘coping with workplace violence’ workshop, gained knowledge, confidence and a sense of self-efficacy with regard to workplace violence. Early detection of signs of imminent violence amongst patients or families and the prevention of its escalation, as well as the ability to manage the threatening situation when occurring, are acquired skills. Encouraging nursing students to learn and practice these skills may enhance their ability to cope with these unfortunate occurrences.

Keywords: early detection of violence, nursing students, patient aggression, self-efficacy, workplace violence

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Authors: K. Mehmood, Muhammad Asif Rafiq, A. Nasir Khan, M. Mudassar Rauf

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Air plasma spraying system was utilized to deposit Ni3Al coatings on AISI 321 steel samples. After thermal spraying, the nickel aluminide intermetallic coatings were isothermal heat treated at various temperatures. In this regard, temperatures from 500 °C to 800 °C with 100 °C increments were selected. The coatings were soaked for 10, 30, 60 and 100 hours at the mentioned temperatures. These coatings were then tested by a pin on disk method. It was observed that the coatings exposed at comparatively higher temperature experienced lower wear rate. The decrease in wear rate is due to the formation of NiO phase. Further, the as sprayed and heat treated coatings were characterized by other tools such as Microhardness testing, optical and scanning electron microscopy (SEM) and X-Ray diffraction analysis. After isothermal heat treatment, NiO was observed the main phase by X-Ray diffraction technique. Moreover, the surface hardness was also determined higher than cross sectional hardness.

Keywords: air plasma spraying, Ni -20Al, tribometer, intermetallic coating, nickel aluminide

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Authors: Yuhao Jin, Zhou Zhou, Katsumi Yoshida, Zhengcao Li, Tadashi Maruyama, Toyohiko Yano

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Four kinds of nuclear graphite, IG-110U, ETP-10, CX-2002U and IG-430U were neutron-irradiated at different fluences and temperatures, ranged from 1.38 x 1024 to 7.4 x 1025 n/m2 (E > 1.0 MeV) at 473K, 573K and 673K. To take into account the disorder in the microstructure, such as stacking faults and anisotropic coherent lengths, the X-ray diffraction patterns were interpreted using a comprehensive structural model and a refinement program CARBONXS. The deduced structural parameters show the changes of lattice parameters, coherent lengths along the c-axis and the basal plane, and the degree of turbostratic disorder as a function of the irradiation dose. Our results reveal neutron irradiation effects on the microstructure and macroscopic dimension, which are consistent with previous work. The methodology used in this work enables the quantification of the damage on the microstructure of nuclear graphite induced by neutron irradiation.

Keywords: nuclear graphite, neutron irradiation, thermal annealing, recovery behavior, dimensional change, CARBONX, XRD analysis

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Authors: Sergio Garcia, Alfredo Trueba, Luis M. Vega, Ernesto Madariaga

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Biofilms adhesion is one of the more important cost of industries plants on wide world, which use to water for cooling heat exchangers or are in contact with water. This study evaluated the effect of Electromagnetic Fields on biofilms in tubular heat exchangers using seawater cooling. The results showed an up to 40% reduction of the biofilm thickness compared to the untreated control tubes. The presence of organic matter was reduced by 75%, the inorganic mater was reduced by 87%, and 53% of the dissolved solids were eliminated. The biofilm thermal conductivity in the treated tube was reduced by 53% as compared to the control tube. The hardness in the effluent during the experimental period was decreased by 18% in the treated tubes compared with control tubes. Our results show that the electromagnetic fields treatment has a great potential in the process of removing biofilms in heat exchanger.

Keywords: biofilm, heat exchanger, electromagnetic fields, seawater

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Authors: Mutasim A. M. Ez Eldin, Tareq Saeid Al Zahrani, Gabel Zamil Al-Barakati, Ibrahim Mohamed AlHarthi, Marwan Mohamed Al Saikhan, Waleed Abdel Aziz Al Aklouk, Waheed Mohamed Saeid Ba Amer

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The Knowledge Economic City (KEC) of Al Madinah Al Munawarah is one of the major projects and represents a cornerstone for the new development activities for Al Madinah. The study area contains different geological units dominated by basalt and overlain by surface deposits. The surface soils vary in thickness and can be classified into well-graded SAND with silt and gravel (SW-SM), silty SAND with gravel (SM), silty GRAVEL with sand (GM), and sandy SILTY clay (CL-ML). The subsurface soil obtained from the drilled boreholes can be classified into poorly graded GRAVEL (GP), well-graded GRAVEL with sand (GW), poorly graded GRAVEL with silt (GP-GM), silty CLAYEY gravel with sand (GC-GM), silty SAND with gravel (SM), silt with SAND (ML), and silty CLAY with sand (CL-ML), sandy lean CLAY (CL), and lean CLAY (CL). The relative density of the deposit and the different gravel sizes intercalated with the soil influenced the Standard Penetration Tests (SPT) values. The SPT N values are high and approach refusal even at shallow depths. The shallow refusal depth (0.10 to 0.90m) of the Dynamic Cone Penetration Test (DCPT) was observed. Generally, the soil can be described as inactive with low plasticity and dense to very dense consistency. The basalt of the KEC site is characterized by slightly (W2) to moderately (W3) weathering, their strength ranges from moderate (S4) to very strong (S2), and the Rock Quality Designation (RQD) ranges from very poor (R5) to excellent (R1). The engineering geological map of the KEC characterized the geoengineering properties of the soil and rock materials and classified them into many zones. The high sulphate (SO₄²⁻) and chloride (Cl⁻) contents in groundwater call for protective measures for foundation concrete. The current study revealed that geohazard(s) mitigation measures concerning floods, volcanic eruptions, and earthquakes should be taken into consideration.

Keywords: engineering geology, KEC, petrographic description, rock and soil investigations

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Authors: Amel Bouaziz, Seddik Khennouf, Mussa Abu Zarga, Shtayway Abdalla, Saliha Djidel, Assia Bentahar, Saliha Dahamna, Smain Amira

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The present study aimed to evaluate the hypotensive and the in vitro antioxidant activities of Crataegus azarolus L. (Rosaceae), a plant widely used as natural remedy for hypertension in folk medicine. The antioxidant potential of methanolic extract (ME)and its three fractions of Chloroform (CHE), ethyl acetate (EAE)and water (AqE) have been investigated using several assays, including the DPPH scavenging, ABTS scavenging, hydroxyl radical scavenging. Inhibition of lipid peroxidation was performed by the β-carotene bleaching assay, ferric thiocyanate method and thiobarburic acid method. Total phenolic and total flavonoid contents of the extracts were estimated using Folin-Chiocalteu reagent and AlCl3, respectively. EAE extract showed the highest polyphenolic and flavonoids contents (396,04±1.20 mg GAE/g of dry extract and 32,73 ± 0.03mg QE/g of dry extract) respectively. Similarly, this extract possessed the highest scavenging activity for DPPH radical (IC 50 = 0,006±0,0001mg /ml), ABTS radical (IC50=0.0035±0,0007 mg/ml) and hydroxyl radical(IC 50=0,283± 0.01 mg/ml). In addition, the EAE exhibited the highest antioxidant activity in the inhibition of linoleic acid/ß-carotene coupled oxidation (89,21%), lipid peroxidation in the ferric thiocyanate(FTC) method (90.13%), and thio-barbituric acid (TBA) method (74.23%). Intravenous administration of Me and EAE decreased mean arterial blood pressure, systolic and diastolic blood pressure in anesthetized rats dose-dependently, at the dose range of 0.4 to 12 mg/kg. The mean arterial blood pressure dropped by 27.58 and 39.37% for ME and EAE, respectively. In conclusion, The present study supported the significant potential to use C. azarolus by-products as a source of natural antioxidants and provides scientific justification for its traditional uses as cardio-protective and anti-hypertensive remedy.

Keywords: Crataegus azarolus, polyphenols, flavonoids, hypertension, antioxidant activity, free radicals, peroxidation

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Authors: Henri Champliaud, Zhengkun Feng, Ngan Van Lê, Javad Gholipour

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In this article, a method is presented to effectively estimate the deformed shape of a thick plate due to line heating. The method uses a fifth order spline interpolation, with up to C3 continuity at specific points to compute the shape of the deformed geometry. First and second order derivatives over a surface are the resulting parameters of a given heating line on a plate. These parameters are determined through experiments and/or finite element simulations. Very accurate kriging models are fitted to real or virtual surfaces to build-up a database of maps. Maps of first and second order derivatives are then applied on numerical plate models to evaluate their evolving shapes through a sequence of heating lines. Adding an optimization process to this approach would allow determining the trajectories of heating lines needed to shape complex geometries, such as Francis turbine blades.

Keywords: deformation, kriging, fifth order spline interpolation, first, second and third order derivatives, C3 continuity, line heating, plate forming, thermal forming

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Authors: Saou Mohamed Amine

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The construction industry has been identified as a user of substantial amount of materials and energy resources that has an enormous impact on environment. The energy efficient in refurbishment project is being considered as one of the approaches to achieve sustainability in construction industry. The increasing concern for environment has made building owners and designers to incorporate the energy efficiency features into their building projects. However, an overwhelming issue of existing non-energy efficient buildings which exceeds the number of new building could be ineffective if the buildings are not refurbished through the energy efficient measures. Thus, energy efficient in refurbishment project is being considered as one of the approaches to achieve sustainability that offers significant opportunities for reducing global energy consumption and greenhouse gas emissions. However, the quality of design team attributes and the characteristics of the refurbishment building projects have been argued to be the main factors that determine the energy efficiency performance of the building.

Keywords: construction industry, design team attributes, energy efficient performance, refurbishment projects characteristics

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Authors: Georgi Vendramin, Aurea Lúcia, Yamamoto, Carlos Itsuo, Camargo Nogueira, Carlos Eduardo, Lenz, Anderson Miguel, Souza Melegari, Samuel N.

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The thermal performance of a solar water heating with 1.00 m2 flat plate collectors in Cascavel-PR, is which presented in this article, paper presents the solution to leverage the marketing of solar heating systems through detailed constituent materials of the solar collector studies, these abundant materials in construction, such as expanded polyethylene, PVC, aluminum and glass tubes, mixing them with new materials to minimize loss of efficiency while decreasing its cost. The system was tested during months and the collector obtained maximum recorded temperature of outlet fluid of 55 °C, while the maximum temperature of the water at the bottom of the hot water tank was 35 °C. The average daily energy collected was 19 6 MJ/d; the energy supplied by the solar plate was 16.2 MJ/d; the loss in the feed pipe was 3.2 MJ/d; the solar fraction was 32.2%, the efficiency of the collector was 45.6% and the efficiency of the system was 37.8%.

Keywords: recycling materials, energy efficiency, solar collector, solar water heating system

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Authors: María Graciela Aguayo, Laura Reyes, Claudia Oviedo, José Navarrete, Liset Gómez, Hugo Torres

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Most wood species used in construction deteriorate when exposed to environmental conditions that favor wood-degrading organisms’ growth. Therefore, chemical protection by impregnation allows more efficient use of forest resources extending the wood useful life. A wood protection treatment which has attracted considerable interest in the scientific community during the last decade is wood impregnation with nano compounds. Radiata pine is the main wood species used in the Chilean construction industry, with total availability of 8 million m³ sawn timber. According to the requirements of the American Wood Protection Association (AWPA) and the Chilean Standards (NCh) radiata pine timber used in construction must be protected due to its low natural durability. In this work, the impregnation with copper nanoparticles (CuNP) was studied in terms of penetration and its protective effect against wood rot fungi. Two concentrations: 1 and 3 g/L of NPCu were applied by impregnation on radiata pine sapwood. Test penetration under AWPA A3-91 standard was carried out, and wood decay tests were performed according to EN 113, with slight modifications. The results of penetration for 1 g/L CuNP showed an irregular total penetration, and the samples impregnated with 3 g/L showed a total penetration with uniform concentration (blue color in all cross sections). The impregnation wood mass losses due to fungal exposure were significantly reduced, regardless of the concentration of the solution or the fungus. In impregnated wood samples, exposure to G. trabeum resulted ML values of 2.70% and 1.19% for 1 g/L and 3 g/L CuNP, respectively, and exposure to P. placenta resulted in 4.02% and 0.70%-ML values for 1 g/L and 3 g/L CuNP, respectively. In this study, the penetration analysis confirmed a uniform distribution inside the wood, and both concentrations were effective against the tested fungi, giving mass loss values lower than 5%. Therefore, future research in wood preservatives should focus on new nanomaterials that are more efficient and environmentally friendly. Acknowledgments: CONICYT FONDEF IDeA I+D 2019, grant number ID19I10122.

Keywords: copper nanoparticles, fungal degradation, radiata pine wood, wood preservation

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Authors: Arthur Baraov

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Nearly all rocket and spacecraft propulsion concepts in existence today can be linked one way or the other to one of the two ancient warfare devices: the gun and the sling. Chemical, thermoelectric, ion, nuclear thermal and electromagnetic rocket engines – all fall into the first group which, for obvious reasons, can be categorized as “hot” space propulsion concepts. Space elevator, orbital tower, rolling satellite, orbital skyhook, tether propulsion and gravitational assist – are examples of the second category which lends itself for the title “cold” space propulsion concepts. The “hot” space propulsion concepts skyrocketed – literally and figuratively – from the naïve ideas of Jules Verne to the manned missions to the Moon. On the other hand, with the notable exception of gravitational assist, hardly any of the “cold” space propulsion concepts made any progress in terms of practical application. Why is that? This article aims to show that the right answer to this question has the potential comparable by its implications and practical consequences to that of transition from Jules Verne’s stillborn and impractical conceptions of space flight to cogent and highly fertile ideas of Konstantin Tsiolkovsky and Yuri Kondratyuk.

Keywords: propulsion, rocket, rollet, spacecraft

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Authors: Mohammed Nabeel Khan, C. Perisamy

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Convective vortices are normal highlights of air that ingest lower-entropy-energy at higher temperatures than they dismiss higher-entropy-energy to space. By means of the thermodynamic proficiency, it has been anticipated that the force of convective vortices relies upon the profundity of the convective layer. The atmospheric vortex engine is proposed as a gadget for delivering mechanical energy by methods for artificially produced vortex. The task of the engine is in view of the certainties that the environment is warmed from the base and cooled from the top. By generation of the artificial vortex, it is planned to take out the physical solar updraft tower and decrease the capital of the solar chimney power plants. The study shows the essentials of the atmospheric vortex engine, furthermore, audits the cutting edge in subject. Moreover, the study talks about a thought on using the solar energy as heat source to work the framework. All in all, the framework is attainable and promising for electrical power production.

Keywords: AVE, atmospheric vortex engine, atmosphere, updraft, vortex

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Authors: Esra Öztürk, Erkul Karacaoglu

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Pyrochlores, having compounds of the general formula, A2B2O7 (A and B are metals/rare earths) are important class of materials thanks to having technological applications like in luminescence, ionic conductivity, nuclear waste immobilization etc. The rare earths included pyrochlore compounds have also potential photoluminescence characteristics. In this context, Er3+-activated Lu2Ti2O7 pyrochlore was chosen and synthesized through a high-temperature solid-state reaction route that was sintered under the open atmosphere in this study. The optimal reaction conditions to obtain expected single phase system, the thermal analysis (DTA/TG) were carried out. The X-ray powder diffraction (XRD) was used to determine phase properties of the sample. The photoluminescence (PL) results were done to obtain excitation, emission and decay time properties by a PL spectrometer under room temperature. According to the PL, there are excitation bands at 352 nm, 388 nm, 423 nm and 453 nm that are due to 4I15/2 → 2G7/2, 4I15/2 → 4G11/2 and 4I15/2 → 4F5/2 transitions of Er3+ ions, respectively. The emission bands are placed at 582 nm, 677 nm and 762 nm that are associated with 2H11/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2, 4I9/2 → 4I15/2 transitions of Er3+ ions, respectively.

Keywords: Er3+, Lu2Ti2O7, photoluminescence, pyrochlore, rare-earths

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Authors: Zenaida Chitu, Roxana Bojariu, Liliana Velea, Roxana Burcea

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A number of studies show that extreme air temperature affects mortality related to cardiovascular diseases, particularly among elderly people. In Romania, the summer thermal discomfort expressed by Universal Thermal Climate Index (UTCI) is highest in the Southern part of the country, where Bucharest, the largest Romanian urban agglomeration, is also located. The urban characteristics such as high building density and reduced green areas enhance the increase of the air temperature during summer. In Bucharest, as in many other large cities, the effect of heat urban island is present and determines an increase of air temperature compared to surrounding areas. This increase is particularly important during heat wave periods in summer. In this context, the researchers performed a temperature-mortality analysis based on daily deaths related to cardiovascular diseases, recorded between 2010 and 2019 in Bucharest. The temperature-mortality relationship was modeled by applying distributed lag non-linear model (DLNM) that includes a bi-dimensional cross-basis function and flexible natural cubic spline functions with three internal knots in the 10th, 75th and 90th percentiles of the temperature distribution, for modelling both exposure-response and lagged-response dimensions. Firstly, this study applied this analysis for the present climate. Extrapolation of the exposure-response associations beyond the observed data allowed us to estimate future effects on mortality due to temperature changes under climate change scenarios and specific assumptions. We used future projections of air temperature from five numerical experiments with regional climate models included in the EURO-CORDEX initiative under the relatively moderate (RCP 4.5) and pessimistic (RCP 8.5) concentration scenarios. The results of this analysis show for RCP 8.5 an ensemble-averaged increase with 6.1% of heat-attributable mortality fraction in future in comparison with present climate (2090-2100 vs. 2010-219), corresponding to an increase of 640 deaths/year, while mortality fraction due to the cold conditions will be reduced by 2.76%, corresponding to a decrease by 288 deaths/year. When mortality data is stratified according to the age, the ensemble-averaged increase of heat-attributable mortality fraction for elderly people (> 75 years) in the future is even higher (6.5 %). These findings reveal the necessity to carefully plan urban development in Bucharest to face the public health challenges raised by the climate change. Paper Details: This work is financed by the project URCLIM which is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by Ministry of Environment, Romania with co-funding by the European Union (Grant 690462). A part of this work performed by one of the authors has received funding from the European Union’s Horizon 2020 research and innovation programme from the project EXHAUSTION under grant agreement No 820655.

Keywords: cardiovascular diseases, climate change, extreme air temperature, mortality

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Authors: Ngozi Claribelle Nwogu, Mohammed Nasir Kajama, Oyoh Kechinyere, Edward Gobina

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Atmospheric carbon dioxide emissions are considered as the greatest environmental challenge the world is facing today. The challenges to control the emissions include the recovery of CO2 from flue gas. This concern has been improved due to recent advances in materials process engineering resulting in the development of inorganic gas separation membranes with excellent thermal and mechanical stability required for most gas separations. This paper therefore evaluates the performance of a highly selective inorganic membrane for CO2 recovery applications. Analysis of results obtained is in agreement with experimental literature data. Further results show the prediction performance of the membranes for gas separation and the future direction of research. The materials selection and the membrane preparation techniques are discussed. Method of improving the interface defects in the membrane and its effect on the separation performance has also been reviewed and in addition advances to totally exploit the potential usage of this innovative membrane.

Keywords: carbon dioxide, gas separation, inorganic ceramic membrane, permselectivity

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Authors: Dalila Hammiche, Lisa Klaai, Sonia Imzi, Amar Boukerrou

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The fight against plastic pollution implies the development of polymers as alternatives to synthetic polymers. Starch is a natural polymer that can easily be plasticized by means of additives. The objective of this work is to develop and characterize biodegradable biofilms based on starch, plasticized by glycerol (20 and 30%). The elaboration of the biofilms was carried out by the casting method under simple conditions. The samples were characterized by infrared spectroscopy analysis with Fourier transform (FTIR), thermogravimetric analysis, and biodegradability test. Infrared spectral analysis showed that the 30% and 20% glycerol films have the same chemical structure and no functional group changes occurred. Thermogravimetric analysis showed that a 30% glycerol film has higher thermal stability than a 20% glycerol film. Biodegradability test showed that the lower the percentage of glycerol, the more easily the biofilm degrades.

Keywords: starch, natural sources, FTIR, thermogravimetric analysis, biodegradability test

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Authors: Sonia Sassi, Mostapha Tarfaoui, Hamza Benyahia

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Composite materials are increasingly being used as a substitute for metallic materials in many technological applications like aeronautics, aerospace, marine and civil engineering applications. For composite materials, the thermomechanical response evolves with the strain rate. The energy balance equation for anisotropic, elastic materials includes heat source terms that govern the conversion of some of the kinetic work into heat. The remainder contributes to the stored energy creating the damage process in the composite material. In this paper, we investigate the bulk thermomechanical behavior of adhesively-bonded composite assemblies to quantitatively asses the temperature rise which accompanies adiabatic deformations. In particular, adhesively bonded joints in glass/vinylester composite material are subjected to in-plane dynamic loads under a range of strain rates. Dynamic thermomechanical behavior of this material is investigated using compression Split Hopkinson Pressure Bars (SHPB) coupled with a high speed infrared camera and a high speed camera to measure in real time the dynamic behavior, the damage kinetic and the temperature variation in the material. The interest of using high speed IR camera is in order to view in real time the evolution of heat dissipation in the material when damage occurs. But, this technique does not produce thermal values in correlation with the stress-strain curves of composite material because of its high time response in comparison with the dynamic test time. For this reason, the authors revisit the application of specific thermocouples placed on the surface of the material to ensure the real thermal measurements under dynamic loading using small thermocouples. Experiments with dynamically loaded material show that the thermocouples record temperatures values with a short typical rise time as a result of the conversion of kinetic work into heat during compression test. This results show that small thermocouples can be used to provide an important complement to other noncontact techniques such as the high speed infrared camera. Significant temperature rise was observed in in-plane compression tests especially under high strain rates. During the tests, it has been noticed that sudden temperature rise occur when macroscopic damage occur. This rise in temperature is linked to the rate of damage. The more serve the damage is, a higher localized temperature is detected. This shows the strong relationship between the occurrence of damage and induced heat dissipation. For the case of the in plane tests, the damage takes place more abruptly as the strain rate is increased. The difference observed in the obtained thermomechanical response in plane compression is explained only by the difference in the damage process being active during the compression tests. In this study, we highlighted the dependence of the thermomechanical response on the strain rate of bonded specimens. The effect of heat dissipation of this material cannot hence be ignored and should be taken into account when defining damage models during impact loading.

Keywords: adhesively-bonded composite joints, damage, dynamic compression tests, energy balance, heat dissipation, SHPB, thermomechanical behavior

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Authors: Aleksander Ejsmont, Aleksandra Galarda, Joanna Goscianska

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Smart porous carriers with defined structure and physicochemical properties are required for releasing the therapeutic drug with precise control of delivery time and location in the body. Due to their non-toxicity, ordered structure, chemical, and thermal stability, mesoporous carbons can be considered as modern carriers for active pharmaceutical ingredients (APIs) whose effectiveness needs frequent dosing algorithms. Such an API-carrier system, if programmed precisely, may stabilize the pharmaceutical and increase its dissolution leading to enhanced bioavailability. The substance conjugated with the material, through its prior adsorption, can later be successfully applied internally to the organism, as well as externally if the API release is feasible under these conditions. In the present study, ordered mesoporous carbons of different morphologies and structures, prepared by hard template method, were applied as carriers in the adsorption and controlled release of active pharmaceutical ingredients. In the first stage, the carbon materials were synthesized and functionalized with carboxylic groups by chemical oxidation using ammonium persulfate solution and then with amine groups. Materials obtained were thoroughly characterized with respect to morphology (scanning electron microscopy), structure (X-ray diffraction, transmission electron microscopy), characteristic functional groups (FT-IR spectroscopy), acid-base nature of surface groups (Boehm titration), parameters of the porous structure (low-temperature nitrogen adsorption) and thermal stability (TG analysis). This was followed by a series of tests of adsorption and release of paracetamol, benzocaine, and losartan potassium. Drug release experiments were performed in the simulated gastric fluid of pH 1.2 and phosphate buffer of pH 7.2 or 6.8 at 37.0 °C. The XRD patterns in the small-angle range and TEM images revealed that functionalization of mesoporous carbons with carboxylic or amine groups leads to the decreased ordering of their structure. Moreover, the modification caused a considerable reduction of the carbon-specific surface area and pore volume, but it simultaneously resulted in changing their acid-base properties. Mesoporous carbon materials exhibit different morphologies, which affect the host-guest interactions during the adsorption process of active pharmaceutical ingredients. All mesoporous carbons show high adsorption capacity towards drugs. The sorption capacity of materials is mainly affected by BET surface area and the structure/size matching between adsorbent and adsorbate. Selected APIs are linked to the surface of carbon materials mainly by hydrogen bonds, van der Waals forces, and electrostatic interactions. The release behavior of API is highly dependent on the physicochemical properties of mesoporous carbons. The release rate of APIs could be regulated by the introduction of functional groups and by changing the pH of the receptor medium. Acknowledgments—This research was supported by the National Science Centre, Poland (project SONATA-12 no: 2016/23/D/NZ7/01347).

Keywords: ordered mesoporous carbons, sorption capacity, drug delivery, carbon nanocarriers

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Authors: Ali Ahmadi, Maryam Abbasi, Mohammad Mehdi Parsaei

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Background: Stress in the workplace today is one of the most important public health concerns and a serious threat to the health of the workforce worldwide. Occupational stress can cause occupational events and reduce quality of life. As a result, it has a very undesirable impact on the performance of organizations, companies, and their human resources. This study aimed to evaluate the relationship between job stress dimensions and occupational accidents in industrial factories in Southwest Iran. Materials and Methods: This cross-sectional study was conducted among 200 workers in the summer of 2023 in the Southwest of Iran. To select participants, we used a convenience sampling method. The research tools in this study were the Health and Safety Executive (HSE) stress questionnaire with 35 questions and 7 dimensions and demographic information. A high score on this questionnaire indicates that there is low job stress and pressure. All workers completed the informed consent form. Univariate analysis was performed using chi-square and T-test. Multiple regression analysis was used to estimate the odds ratios (OR) and 95% confidence interval (CI) for the association of stress-related factors with job accidents in participants. Stata 14.0 software was used for analysis. Results: The mean age of the participants was 39.81(6.36) years. The prevalence of job accidents was 28.0% (95%CI: 21.0, 34.0). Based on the results of the multiple logistic regression with the adjustment of the effect of the confounding variables, one increase in the score of the demand dimension had a protective impact on the risk of job accidents(aOR=0.91,95%CI:0.85-0.95). Additionally, an increase in one of the scores of the managerial support (aOR=0.89, 95% CI: 0.83-0.95) and peer support (aOR=0.76, 95%CI: 0.67-87) dimensions was associated with a lower number of job accidents. Among dimensions, an increase in the score of relationship (aOR=0.89, 95%CI: 0.80-0.98) and change (aOR=0.86, 95%CI: 0.74-0.96) reduced the odds of the accident's occurrence among the workers by 11% and 16%, respectively. However, there was no significant association between role and control dimensions and the job accident (p>0.05). Conclusions: The results show that the prevalence of job accidents was alarmingly high. Our results suggested that an increase in scores of dimensions HSE questioners is significantly associated with a decrease the accident occurrence in the workplace. Therefore, planning to address stressful factors in the workplace seems necessary to prevent occupational accidents.

Keywords: HSE, Iran, job stress occupational accident, safety, occupational health

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Authors: A. Veeresh Babu, M. Vijay Kumar, P. Ravi Kumar, Katam Ganesh Babu

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Biodiesel can be considered as a potential alternative fuel for compression ignition engines. These can be obtained from various resources. However, the usage of biodiesel in high percentage in compression ignition may cause some technical problems because of their higher viscosity, high pour point, and low volatility. Ethanol can be used as a fuel extender to enable use of higher percentage of biodiesel in CI engine. Blends of ethanol-animal fat oil biodiesel-diesel have been prepared and experimental study has been carried out. We have found that B40E20 fuel blend (40% biodiesel and 20 % ethanol in diesel) reduces the specific fuel consumption and improves brake thermal efficiency of engine compared to B40 fuel blend. We observed that fuel characteristics improved considerably with addition of ethanol to biodiesel. Emissions of CO, HC and smoke were reduced while CO2 emissions were increased because of more complete combustion of the blend.

Keywords: diesel, biodiesel, ethanol, CI engine, engine performance, exhaust emission

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Authors: Fernando G. Torres, Omar P. Troncoso

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A wide range of bacteria synthesizes and secretes polymeric substances composed of a mixture of high-molecular-mass heteropolysaccharides. Nostoc commune cyanobacteria grow in colonial spherules of 10-20 mm in diameter. These spherules are filled with an internal gel made from a variety of polysaccharides known as Nostoc commune exopolysaccharides (NCE). In this paper, we report the use of these exopolysaccharides as a raw material for the preparation of a solid polymer electrolyte. Ammonium iodide and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) salts were used to provide NCE films with ionic conductivity. In addition, a carboxymethylation treatment was used to further increase the conductivity of NCE films. The structural characterization of the NCE films was assessed by FTIR, XRD, and DSC tests. Broadband dielectric spectroscopy (BDS) and dielectric thermal analysis (DETA) were used to evaluate the ionic conductivity of the samples. The results showed that NCE can be used to prepare solid polymer electrolyte films and that carboxymethylation improves their ionic conductivity. These NCE films can be used in the development of novel energy storage devices such as flat batteries or supercapacitors.

Keywords: polymer electrolyte, Nostoc commune, cyanobacteria, exopolysaccharides

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Authors: Wanchalerm Patanacharoenwong, Panaya Sudta, Prachya Bumrungkun

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The paper focuses on the development of a system that combines Internet of Things (IoT) technologies and deep learning algorithms for anomaly detection in residential Electric Vehicle (EV) charging in smart cities. With the increasing number of EVs, ensuring efficient and reliable charging systems has become crucial. The aim of this research is to develop an integrated IoT and deep learning system for detecting anomalies in residential EV charging and enhancing EV load profiling and event detection in smart cities. This approach utilizes IoT devices equipped with infrared cameras to collect thermal images and household EV charging profiles from the database of Thailand utility, subsequently transmitting this data to a cloud database for comprehensive analysis. The methodology includes the use of advanced deep learning techniques such as Recurrent Neural Networks (RNN) and Long Short-Term Memory (LSTM) algorithms. IoT devices equipped with infrared cameras are used to collect thermal images and EV charging profiles. The data is transmitted to a cloud database for comprehensive analysis. The researchers also utilize feature-based Gaussian mixture models for EV load profiling and event detection. Moreover, the research findings demonstrate the effectiveness of the developed system in detecting anomalies and critical profiles in EV charging behavior. The system provides timely alarms to users regarding potential issues and categorizes the severity of detected problems based on a health index for each charging device. The system also outperforms existing models in event detection accuracy. This research contributes to the field by showcasing the potential of integrating IoT and deep learning techniques in managing residential EV charging in smart cities. The system ensures operational safety and efficiency while also promoting sustainable energy management. The data is collected using IoT devices equipped with infrared cameras and is stored in a cloud database for analysis. The collected data is then analyzed using RNN, LSTM, and feature-based Gaussian mixture models. The approach includes both EV load profiling and event detection, utilizing a feature-based Gaussian mixture model. This comprehensive method aids in identifying unique power consumption patterns among EV owners and outperforms existing models in event detection accuracy. In summary, the research concludes that integrating IoT and deep learning techniques can effectively detect anomalies in residential EV charging and enhance EV load profiling and event detection accuracy. The developed system ensures operational safety and efficiency, contributing to sustainable energy management in smart cities.

Keywords: cloud computing framework, recurrent neural networks, long short-term memory, Iot, EV charging, smart grids

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Authors: Djalal Hamed

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The aim of this paper is to perform an analytic solution of steady state natural convection in a narrow rectangular channel between two vertical parallel MTR-type fuel plates, imposed under a cosine shape heat flux to determine the margin of the nuclear core power at which the natural convection cooling mode can ensure a safe core cooling, where the cladding temperature should not be reach the specific safety limits (90 °C). For this purpose, a simple computer program is developed to determine the principal parameter related to the nuclear core safety such as the temperature distribution in the fuel plate and in the coolant (light water) as a function of the reactor power. Our results are validated throughout a comparison against the results of another published work, which is considered like a reference of this study.

Keywords: buoyancy force, friction force, natural convection, thermal hydraulic analysis, vertical heated rectangular channel

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Authors: Balwinder Singh

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The present research is a paper on the characterization of aluminum alloy-6063 hybrid metal matrix composites using three different reinforcement materials (SiC, red mud, and fly ash) through stir casting method. The red mud was used in solid form, and particle size range varies between 103-150 µm. During this investigation, fly ash is received from Guru Nanak Dev Thermal Plant (GNDTP), Bathinda. The study has been done by using Taguchi’s L9 orthogonal array by taking fraction wt.% (SiC 5%, 7.5%, and 10% and Red Mud and Fly Ash 2%, 4%, and 6%) as input parameters with their respective levels. The study of the mechanical properties (tensile strength, impact strength, and microhardness) has been done by using Analysis of Variance (ANOVA) with the help of MINITAB 17 software. It is revealed that silicon carbide is the most significant parameter followed by red mud and fly ash affecting the mechanical properties, respectively. The fractured surface morphology of the composites using Field Emission Scanning Electron Microscope (FESEM) shows that there is a good mixing of reinforcement particles in the matrix. Energy-dispersive X-ray spectroscopy (EDS) was performed to know the presence of the phases of the reinforced material.

Keywords: reinforcement, silicon carbide, fly ash, red mud

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Authors: Josee Charette

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The academic and educational success of migrant students is a current issue in education, especially in western societies such in the province of Quebec, in Canada. For people who immigrate with school-age children, the success of the family’s migratory project is often measured by the benefits drawn by children from the educational institutions of their host society. In order to support the academic achievement of their children, migrant parents try to develop practices that derive from their representations of school and related challenges inspired by the socio-cultural context of their country of origin. These findings lead us to the following question: How does strategies implemented by migrant parents to manage the representational distance between school of their country of origin and school of their host society support or not the academic and educational success of their child? In the context of a qualitative exploratory approach, we have made interviews in the French , English and Spanish languages with 32 newly immigrated parents and 10 of their children. Parents were invited to complete a network of free associations about «School in Quebec» as a premise for the interview. The objective of this paper is to present strategies implemented by migrant parents to manage the distance between their representations of schools in their country of origin and in the host society, and to explore the influence of this management on their child’s academic and educational trajectories. Data analysis led us to develop various types of strategies, such as continuity, adaptation, resources mobilization, compensation and "return to basics" strategies. These strategies seem to be part of a continuum from oppositional-conflict scenario, in which parental strategies act as a risk factor, to conciliator-integrator scenario, in which parental strategies act as a protective factor for migrant students’ academic and educational success. In conclusion, we believe that our research helps in highlighting strategies implemented by migrant parents to support their child’s academic and educational success in the host society and also helps in providing a more efficient support to migrant parents and contributes to develop a wider portrait of migrant students’ academic achievement.

Keywords: academic and educational achievement of immigrant students, family’s migratory project, immigrants parental strategies, representational distance between school of origin and school of host society

Procedia PDF Downloads 440