Search results for: high origin radial artery

Authors: Antar Bouhank, Youcef Beellal, Samir Adjel, Abdelmadjid Ababsa

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This paper investigates the impact of 3D printing parameters using the cold metal transfer (CMT) technique on the morphological, mechanical, and tribological properties of walls and massive parts made from aluminum alloy. The parameters studied include current intensity, torch movement speed, printing increment, and the flow rate of shielding gas. The manufactured parts, using the technique mentioned above, are walls and massive parts with different filling strategies, using grid and zigzag patterns and at different current intensities. The main goal of the article is to find out the welding parameters suitable for having parts with low defects and improved properties from the previously mentioned properties point of view. It has been observed from the results thus obtained that the high current intensity causes rapid solidification, resulting in high porosity and low hardness values. However, the high current intensity can cause very rapid solidification, which increases the melting point, and the part remains in the most stable shape. Furthermore, the results show that there is an evident relationship between hardness, coefficient of friction and wear test where the high intensity is, the low hardness is. The same note is for the coefficient of friction. The micrography of the walls shows a random granular structure with fine grain boundaries with a different grain size. Some interesting results are presented in this paper.

Keywords: aluminum alloy, porosity, microstructures, hardness

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Authors: Diana Gibson

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Aim: The first aim of the study was to ascertain the percentage of people who had been diagnosed with High Blood Pressure and/ or Type2 Diabetes Mellitus in Matzikama municipal district, Western Cape, South Africa. These two conditions are reportedly very high in this particular province, even though few statistics are available. A second aim was to gain insight into the understanding of these two conditions among sufferers. A third aim was to determine their allopathic use as well as indigenous medicinal plants to manage these conditions. A fourth aim was to understand how users of medicinal plants attend to their materiality and relationality as a continuum between humans and plants. The final aim was to ascertain the conservation status of medicinal plants utilised. Methods: One thousand one hundred and eighty-four (1184) respondents were interviewed. Semi-structured surveys were utilised to gather data on the percentage of people who had been medically diagnosed with High Blood Pressure and/or Type 2 Diabetes Mellitus. Local healers and knowledgeable old people were subsequently selected through a non-probability snowball sampling method. They were helped with plant collection. The plants were botanically identified. Results: The study found that people who have been diagnosed with High Blood Pressure or Type 2 Diabetes Mellitus drew on and continuously moved between biomedical and local understandings of these conditions. While they followed biomedical treatment regimens as far as possible they also drew on alternative ways of managing it through the use of medicinal plants. The most commonly used plant species overall were Lessertia frutescens, Tulbaghia violacea, Artemisia afra and Leonotus leonurus. For the users, medicinal plants were not mere material entities, they were actants in social networks where knowledge was produced through particular practices in specific places. None of the identified plants are currently threatened. Significance: Sufferers had a good understanding of the symptoms of and biomedical treatment regime for both conditions, but in everyday life they adhered to their local understandings and medicinal plants for treatment. The majority used reportedly used prescribed medication as well as plant alternatives.

Keywords: diabetes, high blood pressure, medicine, plants

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Authors: M. J. Gibbons, A. J. Robinson

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Increasing expectations on small form factor electronics to be more compact while increasing performance has driven conventional cooling technologies to a thermal management threshold. An emerging solution to this problem is electrospray (ES) cooling. ES cooling enables two phase cooling by utilising Coulomb forces for energy efficient fluid atomization. Generated charged droplets are accelerated to the grounded target surface by the applied electric field and surrounding gravitational force. While in transit the like charged droplets enable plume dispersion and inhibit droplet coalescence. If the electric field is increased in the cone-jet regime, a subsequent increase in the plume spray angle has been shown. Droplet segregation in the spray plume has been observed, with primary droplets in the plume core and satellite droplets positioned on the periphery of the plume. This segregation is facilitated by inertial and electrostatic effects. This result has been corroborated by numerous authors. These satellite droplets are usually more densely charged and move at a lower relative velocity to that of the spray core due to the radial decay of the electric field. Previous experimental research by Gomez and Tang has shown that the number of droplets deposited on the periphery can be up to twice that of the spray core. This result has been substantiated by a numerical models derived by Wilhelm et al., Oh et al. and Yang et al. Yang et al. showed from their numerical model, that by varying the extractor potential the dispersion radius of the plume also varies proportionally. This research aims to investigate this dispersion density and the role it plays in the local heat transfer coefficient profile (h) of ES cooling. This will be carried out for different extractor – target separation heights (H2), working fluid flow rates (Q), and extractor applied potential (V2). The plume dispersion will be recorded by spraying a 25 µm thick, joule heated steel foil and by recording the thermal footprint of the ES plume using a Flir A-40 thermal imaging camera. The recorded results will then be analysed by in-house developed MATLAB code.

Keywords: electronic cooling, electrospray, electrospray plume dispersion, spray cooling

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Authors: Z. Herceg, V. Stulic, T. Vukusic, A. Rezek Jambrak

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High voltage electrical discharge plasmas are new nonthermal developing techniques used for water decontamination. To the full understanding of cell inactivation mechanisms, this study brings inactivation, recovery and cellular leakage of L. innocua cells before and after the treatment. Bacterial solution (200 mL) of L. innocua was treated in a glass reactor with a point-to-plate electrode configuration (high voltage electrode-titanium wire, was in the gas phase and grounded electrode was in the liquid phase). Argon was injected into the headspace of the reactor at the gas flow of 5 L/min. Frequency of 60, 90 and 120 Hz, time of 5 and 10 min, positive polarity and conductivity of media of 100 µS/cm were chosen to define listed parameters. With a longer treatment time inactivation was higher as well as the increase in cellular leakage. Despite total inactivation recovery of cells occurred probably because of a high leakage of proteins, compared to lower leakage of nucleic acids (DNA and RNA). In order to define mechanisms of inactivation further research is needed.

Keywords: Listeria innocua ATCC 33092, inactivation, gas phase plasma, cellular leakage, recovery of cells

Procedia PDF Downloads 167

Authors: Guoyu Lin

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This paper explores the role investor sentiment plays in the relationship between analyst forecast dispersion and stock returns. With short sale constraints, stock prices are determined by the optimistic investors. During the high sentiment periods when investors suffer more from psychological bias, there are more optimistic investors. This is the first paper to document that following the high sentiment periods, stocks with the most analyst forecast dispersion are overpriced, earning significantly negative returns, while those with the least analyst forecast dispersion are not overpriced as the degree of belief dispersion is low. However, following the low sentiment periods, both are not overpriced. A portfolio which longs the least dispersed stocks and shorts the most dispersed stocks yields significantly positive returns only following the high sentiment periods. My findings can potentially reconcile the puzzling risk effect and mispricing effect in the literature. The risk (mispricing) effect suggests a positive (negative) relation between analyst forecast dispersion and future stock returns. Presumably, the magnitude of the mispricing effect depends on the proportion of irrational investors and their bias, which is positively related to investor sentiment. During the high sentiment period, the mispricing effect takes over and the overall effect is negative. During the low sentiment period, the percentage of irrational investors is mediate, and the mispricing effect and the risk effect counter each other, leading to insignificant relation.

Keywords: analyst forecast dispersion, short-sale constraints, investor sentiment, stock returns

Procedia PDF Downloads 134

Authors: Usman Abubakar, Xiaoyuan Wang, Sayyed Haleem Shah, Sadiq Ur Rahman, Rabiu Saleh Zakariyya

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High-speed Permanent magnet synchronous machine (HSPMSM) uses in different industrial applications like blowers, compressors as a result of its superb performance. Nevertheless, the over-temperature rise of both winding and PM is one of their substantial problem for a high-power HSPMSM, which affects its lifespan and performance. According to the literature, HSPMSM with a Hybrid cooling configuration has a much lower temperature rise than non-hybrid cooling. This paper presents the design 185kW, 26K rpm with two different cooling configurations, i.e., hybrid cooling configuration (forced air and housing spiral water jacket) and non-hybrid (forced air cooling assisted with winding’s potting material and sleeve’s material) to enhance the heat dissipation of winding and PM respectively. Firstly, the machine’s electromagnetic design is conducted by the finite element method to accurately account for machine losses. Then machine’s cooling configurations are introduced, and their effectiveness is validated by lumped parameter thermal network (LPTN). Investigation shows that using potting, sleeve materials to assist non-hybrid cooling configuration makes the machine’s winding and PM temperature closer to hybrid cooling configuration. Therefore, the machine with non-hybrid cooling is prototyped and tested due to its simplicity, lower energy consumption and can still maintain the lifespan and performance of the HSPMSM.

Keywords: airflow network, axial ventilation, high-speed PMSM, thermal network

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Authors: Pia Ulvenblad, Henrik Barth, Jennie Cederholm BjöRklund, Maya Hoveskog, Per-Ola Ulvenblad

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The importance of business model innovation (BMI) is widely recognized. This is also valid for firms in the agri-food industry, closely connected to global challenges. Worldwide food production will have to increase 70% by 2050 and the United Nations’ sustainable development goals prioritize research and innovation on food security and sustainable agriculture. The firms of the agri-food industry have opportunities to increase their competitive advantage through BMI. However, the process of BMI is complex and the implementation of new business models is associated with high degree of risk and failure. Thus, managers from all industries and scholars need to better understand how to address this complexity. Therefore, the research presented in this paper (i) explores different categories of barriers in research literature on business models in the agri-food industry, and (ii) illustrates categories of barriers with empirical cases. This study is addressing the rather limited understanding on barriers for BMI in the agri-food industry, through a systematic literature review (SLR) of 570 peer-reviewed journal articles that contained a combination of ‘BM’ or ‘BMI’ with agriculture-related and food-related terms (e.g. ‘agri-food sector’) published in the period 1990-2014. The study classifies the barriers in several categories and illustrates the identified barriers with ten empirical cases. Findings from the literature review show that barriers are mainly identified as outcomes. It can be assumed that a perceived barrier to growth can often be initially exaggerated or underestimated before being challenged by appropriate measures or courses of action. What may be considered by the public mind to be a barrier could in reality be very different from an actual barrier that needs to be challenged. One way of addressing barriers to growth is to define barriers according to their origin (internal/external) and nature (tangible/intangible). The framework encompasses barriers related to the firm (internal addressing in-house conditions) or to the industrial or national levels (external addressing environmental conditions). Tangible barriers can include asset shortages in the area of equipment or facilities, while human resources deficiencies or negative willingness towards growth are examples of intangible barriers. Our findings are consistent with previous research on barriers for BMI that has identified human factors barriers (individuals’ attitudes, histories, etc.); contextual barriers related to company and industry settings; and more abstract barriers (government regulations, value chain position, and weather). However, human factor barriers – and opportunities - related to family-owned businesses with idealistic values and attitudes and owning the real estate where the business is situated, are more frequent in the agri-food industry than other industries. This paper contributes by generating a classification of the barriers for BMI as well as illustrating them with empirical cases. We argue that internal barriers such as human factors barriers; values and attitudes are crucial to overcome in order to develop BMI. However, they can be as hard to overcome as for example institutional barriers such as governments’ regulations. Implications for research and practice are to focus on cognitive barriers and to develop the BMI capability of the owners and managers of agri-industry firms.

Keywords: agri-food, barriers, business model, innovation

Procedia PDF Downloads 218

Authors: Bo Hyun Kim, Sarng Woo Karng

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In constructing a hydrogen refueling station, minimizing the volume and reducing the number of banks enable lessening the construction cost. This study aims at performing the dynamic simulation on 250 kg/day of a refueling station for light-duty vehicles. The primary compressor boosts hydrogen from a tube trailer of 250 to 480 bar and stores it in a medium-pressure bank. Then, additional compression of hydrogen from 480 to 900 bar is carried out and stored in a high-pressure bank. Economic analysis was conducted considering the amount of electricity consumed by compression corresponding to the volume and the number of banks (cascade system) in charging mode. NIST REFPROP was selected as the equation of state on the ASPEN HYSYS for thermodynamic analysis of the tube-trailer, the compressors, the chillers, and the banks. Compared to a single high-pressure bank system of 3000 L, the volume of the cascade high-pressure banks (bank1: 250 L and bank 2: 1850 L) was reduced by 30%, and the power consumption of the chiller for precooling was also decreased by 16%.

Keywords: light-duty vehicles, economic analysis, cascade system, hydrogen refueling station

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Authors: Fola John Adeyeye

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In this paper, we propose a cryptosystem private and public key base on symmetric group Pn and validates its theoretical formulation. This proposed system benefits from the algebraic properties of Pn such as noncommutative high logical, computational speed and high flexibility in selecting key which makes the discrete permutation multiplier logic (DPML) resist to attack by any algorithm such as Pohlig-Hellman. One of the advantages of this scheme is that it explore all the possible triangular symmetries. Against these properties, the only disadvantage is that the law of permutation multiplicity only allow an operation from left to right. Many other cryptosystems can be transformed into their symmetric group.

Keywords: cryptosystem, private and public key, DPML, symmetric group Pn

Procedia PDF Downloads 193

Authors: Yanpei Zhen

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The nonlinear Schrödinger (NLS) equation models wave dynamics in many physical problems related to fluids, plasmas, and optics. The standing periodic waves are known to be modulationally unstable, and rogue waves (localized perturbations in space and time) have been observed on their backgrounds in numerical experiments. The exact solutions for rogue waves arising on the periodic standing waves have been obtained analytically. It is natural to ask if the rogue waves persist on the standing periodic waves in the integrable discretizations of the integrable NLS equation. We study the standing periodic waves in the semidiscrete integrable system modeled by the high-order Ablowitz-Ladik (AL) equation. The standing periodic wave of the high-order AL equation is expressed by the Jacobi cnoidal elliptic function. The exact solutions are obtained by using the separation of variables and one-fold Darboux transformation. Since the cnoidal wave is modulationally unstable, the rogue waves are generated on the periodic background.

Keywords: Darboux transformation, periodic wave, Rogue wave, separating the variables

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Authors: Mohadeseh Seyednezhad, Armin Rajabi, Andanastui Muchtar, Mahendra Rao Somalu

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This work investigates the electrical properties of NiO-SDC/SDC anode sintered at about 1200 ○C for 1h through a relatively new approach, namely the microwave method. Nano powders Sm0.2Ce0.8O1.9 (SDC) and NiO were mixed by using a high-energy ball-mill and subsequent co-pressed at three different compaction pressures 200, 300 and 400 MPa. The novelty of this study consists in the effect of compaction pressure on the electrochemical performance of Ni-SDC/SDC anode, with no binder used between layers. The electrical behavior of the prepared anode has been studied by electrochemical impedance spectra (EIS) in controlled atmospheres, operating at high temperatures (600-800 °C).

Keywords: sintering, fuel cell, electrical conductivity, nanostructures, impedance spectroscopy, ceramics

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Authors: M. Pilar Valles-gonzalez, Alejandro Gonzalez Meije, Ana Pastor Muro, Maria Garcia-Martinez, Beatriz Gonzalez Caballero

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This paper studies a failure case of a fuel pressure supply tube from an aircraft engine. Multiple fracture cases of the fuel pressure control tube from aircraft engines have been reported. The studied set was composed of the mentioned tube, a welded connecting pipe, where the fracture has been produced, and a union nut. The fracture has been produced in one most critical zones of the tube, in a region next to the supporting body of the union nut to the connector. The tube material was X6CrNiTi18-10, an austenitic stainless steel. Chemical composition was determined using an X-Ray fluorescence spectrometer (XRF) and combustion equipment. Furthermore, the material has been mechanical, by hardness test, and microstructural characterized using a stereomicroscope and an optical microscope. The results confirmed that it is within specifications. To determine the macrofractographic features, a visual examination and a stereo microscope of the tube fracture surface have been carried out. The results revealed a tube plastic macrodeformation, surface damaged, and signs of a possible corrosion process. Fracture surface was also inspected by scanning electron microscopy (FE-SEM), equipped with a microanalysis system by X-ray dispersive energy (EDX), to determine the microfractographic features in order to find out the failure mechanism involved in the fracture. Fatigue striations, which are typical from a progressive fracture by a fatigue mechanism, have been observed. The origin of the fracture has been placed in defects located on the outer wall of the tube, leading to a final overload fracture.

Keywords: aircraft engine, fatigue, FE-SEM, fractography, fracture, fuel tube, microstructure, stainless steel

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Authors: Raghabendra Yadav, Baochun Chen, Huihui Yuan, Zhibin Lian

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Concrete Filled Steel Tube (CFST) columns are widely used in Civil Engineering Structures due to their abundant properties. CFST-RC column is a built up column in which CFST members are connected with RC web. The CFST-RC column has excellent static and earthquake resistant properties, such as high strength, high ductility and large energy absorption capacity. CFST-RC columns have been adopted as piers in Ganhaizi Bridge in high seismic risk zone with a highest pier of 107m. The experimental investigation on scaled models of similar type of the CFST-RC pier are carried out. The experimental investigation on scaled models of similar type of the CFST-RC pier are carried out. Under cyclic loading, the hysteretic performance of CFST-RC columns, such as failure modes, ductility, load displacement hysteretic curves, energy absorption capacity, strength and stiffness degradation are studied in this paper.

Keywords: CFST, cyclic load, Ganhaizi bridge, seismic performance

Procedia PDF Downloads 238

Authors: Himali N. Balasooriya, Kithsiri B. Dassanayake, Saman Seneweera, Said Ajlouni

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Increase in atmospheric CO₂ concentration [CO₂] and ambient temperature associated with changing climatic conditions will have significant impacts on agriculture crop productivity and quality. Independent effects of the above two environmental variables on the growth, yield and quality of strawberry were well documented. Higher temperatures over the optimum range (20-25ºC) lead to crop failures, while elevated [CO₂] stimulated plant growth and yield but compromised the physical quality of fruits. However, there is very limited understanding of the interaction between these variables on the plant growth, yield and quality. Therefore, this study was designed to investigate the interactive effect of high temperature and elevated [CO₂] on growth, yield and quality of strawberries. Strawberry cultivars ‘Albion’ and ‘San Andreas’ were grown under six different combinations of two temperatures (25 and 30ºC) and three [CO₂] (400, 650 and 950 µmol mol^-1) in controlled-environmental growth chambers. Plant growth measurements such as plant height, canopy area, number of flowers, and fruit yield were measured during phonological development. Photosynthesis and transpiration, the ratio of intercellular to atmospheric [CO₂] (Ci/Ca) were measured to estimate the physiological adjustment to climate stress. The impact of temperature and [CO₂] interaction on growth and yield of strawberry was significant (p < 0.05). Across both cultivars, highest fruit yields were observed at 650 µmol mol^-1 [CO₂], which was particularly clear at 25°C. The fruit yield gradually decreased at 30°C under all the treatment combinations. However, photosynthesis rates were highest at 650 µmol mol^-1 [CO₂] but no increment was found at 900 µmol mol^-1 [CO₂]. Interestingly, Ci/Ca ratio increased with increasing atmospheric [CO₂] which was predominant at high temperature. Similarly, fruit yield was substantially reduced at high [CO₂] under high temperature. Our findings suggest that increased Ci/Ca ratio at high temperature is likely reduces the photosynthesis and thus yield response to elevated [CO₂].

Keywords: atmospheric CO₂ concentration, fruit yield, strawberry, temperature

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Authors: Chen Yong, Bi Wangyang, Zang Libin, Li Jinkai, Cheng Xiaowei, Liu Jinmin, Yu Miao

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New energy vehicle power transmission systems continue to develop in the direction of high torque, high speed, and high efficiency. The cooling and lubrication of the motor and the transmission system are integrated, and new requirements are placed on the lubricants for the transmission system. The effects of traditional lubricants and special lubricants for new energy vehicles on transmission efficiency were studied through experiments and simulation methods. A mathematical model of the transmission efficiency of the lubricating oil in the gearbox was established. The power loss of each part was analyzed according to the working conditions. The relationship between the speed and the characteristics of different lubricating oil products on the power loss of the stirring oil was discussed. The minimum oil film thickness was required for the life of the gearbox. The accuracy of the calculation results was verified by the transmission efficiency test conducted on the two-motor integrated test bench. The results show that the efficiency increases first and then decreases with the increase of the speed and decreases with the increase of the kinematic viscosity of the lubricant. The increase of the kinematic viscosity amplifies the transmission power loss caused by the high speed. New energy vehicle special lubricants have less attenuation of transmission efficiency in the range above mid-speed. The research results provide a theoretical basis and guidance for the evaluation and selection of transmission efficiency of gearbox lubricants for new energy vehicles.

Keywords: new energy vehicles, lubricants, transmission efficiency, kinematic viscosity, test and simulation

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Authors: Raphael C. Zero, Marita V. Cardozo, Thiago A. S. S. Rocha, Mariana T. Kihara, Fernando A. Ávila, Fabrício S. Oliveira

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There are several fixative and preservative solutions for use on cadavers, many of them using formaldehyde as the fixative or anatomical part preservative. In some countries, such as Brazil, this toxic agent has been increasingly restricted. The objective of this study was to microbiologically identify and quantify the key agents in tanks containing 96GL ethanol or sodium chloride solutions, used respectively as fixatives and preservatives of cat cadavers. Eight adult cat corpses, three females and five males, with an average weight of 4.3 kg, were used. After injection via the external common carotid artery (120 ml/kg, 95% 96GL ethyl alcohol and 5% pure glycerin), the cadavers were fixed in a plastic tank with 96GL ethanol for 60 days. After fixing, they were stored in a 30% sodium chloride aqueous solution for 120 days in a similar tank. Samples were collected at the start of the experiment - before the animals were placed in the ethanol tanks, and monthly thereafter. The bacterial count was performed by Pour Plate Method in BHI agar (Brain Heart Infusion) and the plates were incubated aerobically and anaerobically for 24h at 37ºC. MacConkey agar, SPS agar (Sulfite Polymyxin Sulfadizine) and MYP Agar Base were used to isolate the microorganisms. There was no microbial growth in the samples prior to alcohol fixation. After 30 days of fixation in the alcohol solution, total aerobic and anaerobic (<1.0 x 10 CFU/ml) were found and Pseudomonas sp., Staphylococcus sp., Clostridium sp. were the identified agents. After 60 days in the alcohol fixation solution, total aerobes (<1.0 x 10 CFU/ml) and total anaerobes (<2.2 x 10 CFU/mL) were found, and the identified agents were the same. After 30 days of storage in the aqueous solution of 30% sodium chloride, total aerobic (<5.2 x 10 CFU/ml) and total anaerobes (<3.7 x 10 CFU/mL) were found and the agents identified were Staphylococcus sp., Clostridium sp., and fungi. After 60 days of sodium chloride storage, total aerobic (<3.0 x 10 CFU / ml) and total anaerobes (<7.0 x 10 CFU/mL) were found and the identified agents remained the same: Staphylococcus sp., Clostridium sp., and fungi. The microbiological count was low and visual inspection did not reveal signs of contamination in the tanks. There was no strong odor or purification, which proved the technique to be microbiologically effective in fixing and preserving the cat cadavers for the four-month period in which they are provided to undergraduate students of University of Veterinary Medicine for surgery practice. All experimental procedures were approved by the Municipal Legal Department (protocol 02.2014.000027-1). The project was funded by FAPESP (protocol 2015-08259-9).

Keywords: anatomy, fixation, microbiology, small animal, surgery

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Authors: Victoria L. Chester, Usha Kuruganti

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The forest industry is a major economic sector of Canada and also one of the most dangerous industries for workers. The use of mechanized mobile forestry harvesting machines has successfully reduced the incidence of injuries in forest workers related to manual labor. However, these machines have also created additional concerns, including a high machine operation learning curve, increased the length of the workday, repetitive strain injury, cognitive load, physical and mental fatigue, and increased postural loads due to sitting in a confined space. It is critical to obtain objective performance data for employers to develop appropriate work practices for this industry, however ergonomic field studies of this industry are lacking mainly due to the difficulties in obtaining comprehensive data while operators are cutting trees in the woods. The purpose of this study was to establish a measurement and experimental protocol to examine the effects of worker skill level and movement training speed (joystick crane speed) on harvesting performance using a forestry simulator. A custom wrist angle measurement device was developed as part of the study to monitor Euler angles during operation of the simulator. The device of the system consisted of two accelerometers, a Bluetooth module, three 3V coin cells, a microcontroller, a voltage regulator and an application software. Harvesting performance and crane data was provided by the simulator software and included tree to frame collisions, crane to tree collisions, boom tip distance, number of trees cut, etc. A pilot study of 3 operators with various skill levels was tested to identify factors that distinguish highly skilled operators from novice or intermediate operators. Dependent variables such as reaction time, math skill, past work experience, training movement speed (e.g. joystick control speeds), harvesting experience level, muscle activity, and wrist biomechanics were measured and analyzed. A 10-channel wireless surface EMG system was used to monitor the amplitude and mean frequency of 10 upper extremity muscles during pre and postperformance on the forestry harvest stimulator. The results of the pilot study showed inconsistent changes in median frequency pre-and postoperation, but there was the increase in the activity of the flexor carpi radialis, anterior deltoid and upper trapezius of both arms. The wrist sensor results indicated that wrist supination and pronation occurred more than flexion and extension with radial-ulnar rotation demonstrating the least movement. Overall, wrist angular motion increased as the crane speed increased from slow to fast. Further data collection is needed and will help industry partners determine those factors that separate skill levels of operators, identify optimal training speeds, and determine the length of training required to bring new operators to an efficient skill level effectively. In addition to effective and employment training programs, results of this work will be used for selective employee recruitment strategies to improve employee retention after training. Further, improved training procedures and knowledge of the physical and mental demands on workers will lead to highly trained and efficient personnel, reduced risk of injury, and optimal work protocols.

Keywords: EMG, forestry, human factors, wrist biomechanics

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Authors: Dairi Sabri, Mrad Dounia, Djebbar Yassine, Abida Habib

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Food security, which may be ensured by important agricultural production, needs huge amounts of water for irrigation. Recognizing this, the Algerian government made enormous efforts to mobilize water resources. Every drop of water collected, regardless of its origin, is needed to strengthen agricultural production. The present irrigated area in Algeria is about 1 million hectares while the potential agricultural area all over the country exceeds 9 million ha. This clearly shows the need for non-conventional water resources in Algeria, especially treated wastewater reuse. The use of treated wastewater in agricultural irrigation is still at the experimental stage in Algeria. While 20 million hectares worldwide are irrigated with treated wastewater, only 2300 hectares in Algeria are irrigated on an experimental basis in the regions of Setif, Constantine, Mila Telemcen, Tougourt and Boumerdès. The volume of wastewater discharged nationwide is estimated to be around 750 million cubic meters and is expected to exceed 1.5 billion m3 in 2020. An ambitious program of providing treatment facilities has been initiated in this direction to increase the treatment capacity to 2.5 million m3 per day in 2030. In order to optimize the use of this resource, specific research actions interested in defining treated wastewater reuse opportunities and standards are undertaken. The objective of this study is basically to examine the different components of treated wastewater reuse, including standards, treatment processes, agricultural opportunities and potentials as well as technical and economic aspects governing the feasibility of this technology in Algeria based on Geographic Information System (GIS).

Keywords: wastewater reuse, integrated management, irrigation, GIS

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Authors: G. Hosseini, A. Sadighzadeh, M. Rahimnejad, N. Hosseini, Z. Jamalzadeh

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Metal pollutants, especially heavy metals from anthropogenic sources such as metallurgical industries’ waste including mining, smelting, casting or production of nuclear fuel, including mining, concentrate production and uranium processing ends in the environment contamination (water and soil) and risk to human health around the facilities of this type of industrial activity. There are different methods that can be used to remove these contaminants from water and soil. These are very expensive and time-consuming. In this case, the people have been forced to leave the area and the decontamination is not done. For example, in the case of Chernobyl accident, an area of 30 km around the plant was emptied of human life. A very efficient and cost-effective method for decontamination of the soil and the water is phytoremediation. In this method, the plants preferentially native plants which are more adaptive to the regional climate are well used. In this study, three types of plants including Alfalfa, Sunflower and wheat were used to Barium decontamination. Alfalfa and Sunflower were not grown good enough in Saghand mine’s soil sample. This can be due to non-native origin of these plants. But, Wheat rise in Saghand Uranium Mine soil sample was satisfactory. In this study, we have investigated the effect of 4 types of acids inclusive nitric acid, oxalic acid, acetic acid and citric acid on the removal efficiency of Barium by Wheat. Our results indicate the increase of Barium absorption in the presence of citric acid in the soil. In this paper, we will present our research and laboratory results.

Keywords: phytoremediation, heavy metal, wheat, soil

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Authors: Jifang Tao, Fei Gao, Hong Cai, Yuan Jin Zheng, Yuan Dong Gu

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Photoacoustic technology is used to measure effect absorption of a light by means of acoustic detection, which provides a high sensitive, low-cross response, cost-effective solution for gas molecular detection. In this paper, we proposed an integrated photoacoustic sensor for Indoor-air quality (IAQ) monitoring. The sensor consists of an acoustically resonant cavity, a high silicon acoustic transducer chip, and a low-cost light source. The light is modulated at the resonant frequency of the cavity to create an enhanced periodic heating and result in an amplified acoustic pressure wave. The pressure is readout by a novel acoustic transducer with low noise. Based on this photoacoustic sensor, typical indoor gases, including CO2, CO, O2, and H2O have been successfully detected, and their concentration are also evaluated with very high accuracy. It has wide potential applications in IAQ monitoring for agriculture, food industry, and ventilation control systems used in public places, such as schools, hospitals and airports.

Keywords: indoor-air quality (IAQ) monitoring, photoacoustic gas sensor, cavity enhancement, integrated gas sensor

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Authors: Jun-Hyeon Cho, Ji-Yoon Lee, Young-Bo Sohn, Dong-Jin Shin, You-Chun Song, Dong-Soo Park, Min-Hee Nam, Young-Up Kwon

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Seed germination is a main factor in japonica rice cultivation. For japonica strains unlike indica lines, fast loss of germination ability during storage leads to risk of seeding and deterioration in the quality. To resolve these problems, germplasms screening for longevity was conducted using six days of compulsory aging stress of high temperature (50℃) and humidity (~95% RH). ‘Dharial’, a weedy rice collected in Bangladesh, was chosen as a source of seed longevity for long term storage. The strong germination trait originated from ‘Dharial’ was incorporated into Korean elite japonica cultivars, ‘Ilmi’ and ‘Gopum’, through backcross method. The germination ratio was evaluated after two years of room temperature storage conditions. A high germination ratio of 80.5% in donor plant of ‘Dharial’ and 77.3% in an introgression line were observed based on the two years of storage while the recurrent japonica cultivars, ‘Ilmi’ and ‘Gopum’, were failed in germination. As a result, we investigated the changes of quality affected by germination ability during storage. A gentle slope of palatability which is one of the measurement items for indirect selection indicator of high eating quality in japonica varieties was studied in a high germination ratio introgression line during storage. The introgression line could be useful to increase longevity and quality of japonica rice seed if molecular breeding strategy such as QTLs analysis is combined.

Keywords: rice, longevity, germination, storage

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Authors: Rasha A.Ibrahim El-Ghazawy, Ashraf M. El-Saeed, Heusin El-Shafey, M. Abdel-Raheim, Maher A. El-Sockary

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Two thermotropic liquid crystalline curing agents based on abietic acid with different mesogens (LCC1 and LCC2) were synthesized for producing thermally stable liquid crystal networks suitable for high performance epoxy coatings. Differential scanning calorimetry (DSC) and polarized optical microscope (POM) was used to identify the liquid crystal phase transformation temperatures and texture, respectively. POM micro graphs for both LCCs revealing cholesteric texture. A multifunctional epoxy resin with two abietic acid moieties was also synthesized. Dynamic mechanical (DMA) and thermogravimetric (TGA) analyses show that the fully bio-based cured epoxies by either LCCs possess high glass transition temperature (Tg), high modulus (G`) and improved thermal stability. The chemical structure of the synthesized LCCs and epoxy resin was investigated through FTIR and 1HNMR spectroscopic techniques.

Keywords: abietic acid, dynamic mechanical analysis, epoxy resin, liquid crystal, thermo gravimetric analysis

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Authors: Idit Avrahami, Alex Schechter, Lev Zakhvatkin

Abstract:

This research focuses on developing a compact and light Hydrogen Generator (HG), coupled with fuel cells (FC) to provide a High-Energy-Density Power-Pack (HEDPP) solution, which is 10 times Li-Ion batteries. The HEDPP is designed for portable & off-grid power applications such as Drones, UAVs, stationary off-grid power sources, unmanned marine vehicles, and more. Hydrogen gas provided by this device is delivered in the safest way as a chemical powder at room temperature and ambient pressure is activated only when the power is on. Hydrogen generation is based on a stabilized chemical reaction of Sodium Borohydride (SBH) and water. The proposed solution enables a ‘No Storage’ Hydrogen-based Power Pack. Hydrogen is produced and consumed on-the-spot, during operation; therefore, there’s no need for high-pressure hydrogen tanks, which are large, heavy, and unsafe. In addition to its high energy density, ease of use, and safety, the presented power pack has a significant advantage of versatility and deployment in numerous applications and scales. This patented HG was demonstrated using several prototypes in our lab and was proved to be feasible and highly efficient for several applications. For example, in applications where water is available (such as marine vehicles, water and sewage infrastructure, and stationary applications), the Energy Density of the suggested power pack may reach 2700-3000 Wh/kg, which is again more than 10 times higher than conventional lithium-ion batteries. In other applications (e.g., UAV or small vehicles) the energy density may exceed 1000 Wh/kg.

Keywords: hydrogen energy, sodium borohydride, fixed-wing UAV, energy pack

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Authors: Davit Pipoyan, Meline Beglaryan, Nicolò Merendino

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Mining industry is one of the priority sectors of Armenian economy. Along with the solution of some socio-economic development, it brings about numerous environmental problems, especially toxic element pollution, which largely influences the safety of agricultural products. In addition, accumulation of toxic elements in agricultural products, mainly in edible parts of plants represents a direct pathway for their penetration into the human food chain. In Armenia, the share of plant origin food in overall diet is significantly high, so estimation of dietary intakes of toxic trace elements via consumption of selected fruits and vegetables are of great importance for observing the underlying health risks. Therefore, the present study was aimed to assess dietary exposure of potentially toxic trace elements through the intake of locally grown fruits and vegetables in Akhtala community (Armenia), where not only mining industry is developed, but also cultivation of fruits and vegetables. Moreover, this investigation represents one of the very first attempts to estimate human dietary exposure of potentially toxic trace elements in the study area. Samples of some commonly grown fruits and vegetables (fig, cornel, raspberry, grape, apple, plum, maize, bean, potato, cucumber, onion, greens) were randomly collected from several home gardens located near mining areas in Akhtala community. The concentration of Cu, Mo, Ni, Cr, Pb, Zn, Hg, As and Cd in samples were determined by using an atomic absorption spectrophotometer (AAS). Precision and accuracy of analyses were guaranteed by repeated analysis of samples against NIST Standard Reference Materials. For a diet study, individual-based approach was used, so the consumption of selected fruits and vegetables was investigated through food frequency questionnaire (FFQ). Combining concentration data with contamination data, the estimated daily intakes (EDI) and cumulative daily intakes were assessed and compared with health-based guidance values (HBGVs). According to the determined concentrations of the studied trace elements in fruits and vegetables, it can be stressed that some trace elements (Cu, Ni, Pb, Zn) among the majority of samples exceeded maximum allowable limits set by international organizations. Meanwhile, others (Cr, Hg, As, Cd, Mo) either did not exceed these limits or still do not have established allowable limits. The obtained results indicated that only for Cu the EDI values exceeded dietary reference intake (0.01 mg/kg/Bw/day) for some investigated fruits and vegetables in decreasing order of potato > grape > bean > raspberry > fig > greens. In contrast to this, for combined consumption of selected fruits and vegetables estimated cumulative daily intakes exceeded reference doses in the following sequence: Zn > Cu > Ni > Mo > Pb. It may be concluded that habitual and combined consumption of the above mentioned fruits and vegetables can pose a health risk to the local population. Hence, further detailed studies are needed for the overall assessment of potential health implications taking into consideration adverse health effects posed by more than one toxic trace element.

Keywords: daily intake, dietary exposure, fruits, trace elements, vegetables

Procedia PDF Downloads 287

Authors: Nadine Raidl, Benjamin Kaufmann, Michael Hofstätter, Peter Supancic

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If polycrystalline ZnO is properly doped and sintered under very specific conditions, it shows unique electrical properties, which are indispensable for today’s electronic industries, where it is used as the number one overvoltage protection material. Under a critical voltage, the polycrystalline bulk exhibits high electrical resistance but becomes suddenly up to twelve magnitudes more conductive if this voltage limit is exceeded (i.e., varistor effect). It is known that these peerless properties have their origin in the grain boundaries of the material. Electric charge is accumulated in the boundaries, causing a depletion layer in their vicinity and forming potential barriers (so-called Double Schottky Barriers, or DSB) which are responsible for the highly non-linear conductivity. Since ZnO is a piezoelectric material, mechanical stresses induce polarisation charges that modify the DSB heights and as a result the global electrical characteristics (i.e., piezotronic effect). In this work, a finite element method was used to simulate emerging stresses on individual grains in the bulk. Besides, experimental efforts were made to testify a coherent model that could explain this influence. Electron back scattering diffraction was used to identify grain orientations. With the help of wet chemical etching, grain polarization was determined. Micro lock-in infrared thermography (MLIRT) was applied to detect current paths through the material, and a micro 4-point probes method system (M4PPS) was employed to investigate current-voltage characteristics between single grains. Bulk samples were tested under uniaxial pressure. It was found that the conductivity can increase by up to three orders of magnitude with increasing stress. Through in-situ MLIRT, it could be shown that this effect is caused by the activation of additional current paths in the material. Further, compressive tests were performed on miniaturized samples with grain paths containing solely one or two grain boundaries. The tests evinced both an increase of the conductivity, as observed for the bulk, as well as a decreased conductivity. This phenomenon has been predicted theoretically and can be explained by piezotronically induced surface charges that have an impact on the DSB at the grain boundaries. Depending on grain orientation and stress direction, DSB can be raised or lowered. Also, the experiments revealed that the conductivity within one single specimen can increase and decrease, depending on the current direction. This novel finding indicates the existence of asymmetric Double Schottky Barriers, which was furthermore proved by complementary methods. MLIRT studies showed that the intensity of heat generation within individual current paths is dependent on the direction of the stimulating current. M4PPS was used to study the relationship between the I-V characteristics of single grain boundaries and grain orientation and revealed asymmetric behavior for very specific orientation configurations. A new model for the Double Schottky Barrier, taking into account the natural asymmetry and explaining the experimental results, will be given.

Keywords: Asymmetric Double Schottky Barrier, piezotronic, varistor, zinc oxide

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Authors: Jose Ramon Sanabria Navarro, Yahilina Silveira Perez, Valentin Molina Moreno, Digna Dionisia Perez Bravo

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The general objective of this research is to conceive a model of strategic direction for Latin American high-performance sports centers for the improvement of their results. The sample is 62 managers, 187 trainers, 2930 athletes and 62 expert researchers from centers in Cuba, Venezuela, Ecuador, Colombia and Argentina, for 3241. The measurement instrument includes 12 key variables in the process of management strategies which are consolidated with the factorial analysis and the ANOVA of a factor through the SPSS 24.0. The reliability of the scale obtained an alpha higher than 0.7 in each sample. In this sense, a model is obtained that taxes the deficiencies detected in the diagnosis, based on the needs of the members of these organizations, considering criteria and theories of the strategic direction in the improvement of the organizational results. The validation of the model for high performance sports centers of the countries analyzed aims to develop joint strategies to generate synergies in their operational mode, which leads to enhance the sports organization.

Keywords: sports organization, information management, decision making, control

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Authors: Stefano Frassinelli, Alessandro Niccolai, Riccardo E. Zich

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Sport performance analysis is a technique that is becoming every year more important for athletes of every level. Many techniques have been developed to measure and analyse efficiently the performance of athletes in some sports, but in combat sports these techniques found in many times their limits, due to the high interaction between the two opponents during the competition. In this paper the problem will be framed. Moreover the physical performance measurement problem will be analysed and three different techniques to manage it will be presented. All the techniques have been used to analyse the performance of 22 high level Judo athletes.

Keywords: sport performance, physical performance, judo, performance coefficients

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Authors: Isyaka Abdulkadir, Egbe Ngu-Ntui Ogork

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This research aims to investigate the use of Scrap Tyre Steel Fibers (STSF) for the production of fiber reinforced high performance concrete. The Scrap Tyre Steel Fibers (STSF) were obtained from dealers that extracted the fibers by burning the scrap tyres and were characterized. The effect of STSF was investigated on grade 50 concrete of 1:1.28:1.92 with water cement ratio of 0.39 at additions of STSF of 0, 0.5, 1.0, 1.5, 2.0 and 2.5% by volume of concrete. The fresh concrete was tested for slump while the hardened concrete was tested for compressive and splitting tensile strengths, respectively at curing ages of 3, 7, 28 and 56 days in accordance with standard procedure. The results indicate that slump decreased with increase in STSF, while compressive and splitting tensile strengths increased with increase in STSF up to 1.5% and reduction in strength with increase in STSF above 1.5%. 1.5% STSF was considered as the optimum dosage with a 28 days increase in compressive strength and splitting tensile strength of 12.3% and 43.8% respectively, of control.

Keywords: compressive strength, high performance concrete, scrap tyre steel fiber, splitting tensile strength

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Authors: Ali Azeem, Seung-Cheol Hong

Abstract:

This study focuses on the epidemiological association between childhood leukaemia & adult brain cancer to offer strong evidence that extremely low-frequency magnetic field (ELF-MF) produced from power lines caused cancer. It also gives a comprehensive literature review on epidemiological studies of ELF-MF risk associated with HVTL and childhood leukaemia & adult brain cancer. From the literature review, it is concluded that there is a weak association present between ELF-MF and childhood leukaemia. No consistent association was present between brain cancer and ELF-MF. This study is done on Scielo data and PubMed using the terms extremely low-frequency magnetic field (ELF-MF+cancer), adult brain cancer, high power transmission lines, etc., for the past 10 years.

Keywords: childhood leukaemia, high voltage transmission lines, acute lymphoblastic leukaemia, power lines

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Authors: Andrés Durán, Brian Castellanos, Marta Quicazán, Carlos Zuluaga-Domínguez

Abstract:

Bee-pollen is an apicultural-derived food product, with a growing appreciation among consumers given the remarkable nutritional and functional composition, in particular, protein (24%), dietary fiber (15%), phenols (15 – 20 GAE/g) and carotenoids (600 – 900 µg/g). These properties are given by the geographical and climatic characteristics of the region where it is collected. There are several countries recognized by their pollen production, e.g. China, United States, Japan, Spain, among others. Beekeepers use traps in the entrance of the hive where bee-pollen is collected. After the removal of foreign particles and drying, this product is ready to be marketed. However, in countries located along the equator, the absence of seasons and a constant tropical climate throughout the year favors a more rapid spoilage condition for foods with elevated water activity. The climatic conditions also trigger the proliferation of microorganisms and insects. This, added to the factor that beekeepers usually do not have adequate processing systems for bee-pollen, leads to deficiencies in the quality and safety of the product. In contrast, the Andean region of South America, lying on equator, typically has a high production of bee-pollen of up to 36 kg/year/hive, being four times higher than in countries with marked seasons. This region is also located in altitudes superior to 2500 meters above sea level, having extremes sun ultraviolet radiation all year long. As a mechanism of defense of radiation, plants produce more secondary metabolites acting as antioxidant agents, hence, plant products such as bee-pollen contain remarkable more phenolics and carotenoids than collected in other places. Considering this, the improvement of bee-pollen processing facilities by technical modifications and the implementation of an integrated cleaning and drying system for the product in an apiary in the area was proposed. The beehives were modified through the installation of alternative bee-pollen traps to avoid sources of contamination. The processing facility was modified according to considerations of Good Manufacturing Practices, implementing the combined use of a cabin dryer with temperature control and forced airflow and a greenhouse-type solar drying system. Additionally, for the separation of impurities, a cyclone type system was implemented, complementary to a screening equipment. With these modifications, a decrease in the content of impurities and the microbiological load of bee-pollen was seen from the first stages, principally with a reduction of the presence of molds and yeasts and in the number of foreign animal origin impurities. The use of the greenhouse solar dryer integrated to the cabin dryer allowed the processing of larger quantities of product with shorter waiting times in storage, reaching a moisture content of about 6% and a water activity lower than 0.6, being appropriate for the conservation of bee-pollen. Additionally, the contents of functional or nutritional compounds were not affected, even observing an increase of up to 25% in phenols content and a non-significant decrease in carotenoids content and antioxidant activity.

Keywords: beekeeping, drying, food processing, food safety

Procedia PDF Downloads 97