Search results for: testing fresh concrete

Authors: Minal Jain, Vinayak Malhotra

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Solid Propellant ignition consists of rapid and complex events comprising of heat generation and transfer of heat with spreading of flames over the entire burning surface area. Proper combustion and thus propulsion depends heavily on the modes of heat transfer characteristics and cavity volume. Fire safety is an integral component of a successful rocket flight failing to which may lead to overall failure of the rocket. This leads to enormous forfeiture in resources viz., money, time, and labor involved. When the propellant is ignited, thrust is generated and the casing gets heated up. This heat adds on to the propellant heat and the casing, if not at proper orientation starts burning as well, leading to the whole rocket being completely destroyed. This has necessitated active research efforts emphasizing a comprehensive study on the inter-energy relations involved for effective utilization of the solid rocket motors for better space missions. Present work is focused on one of the major influential aspects of this detrimental burning which is the presence of an external heat source, in addition to a potential heat source which is already ignited. The study is motivated by the need to ensure better combustion and fire safety presented experimentally as a simplified small-scale mode of a rocket carrying a solid propellant inside a cavity. The experimental setup comprises of a paraffin wax candle as the pilot fuel and incense stick as the external heat source. The candle is fixed and the incense stick position and location is varied to investigate the find the influence of the pilot heat source. Different configurations of the external heat source presence with separation distance are tested upon. Regression rates of the pilot thin solid fuel are noted to fundamentally understand the non-linear heat and mass transfer which is the governing phenomenon. An attempt is made to understand the phenomenon fundamentally and the mechanism governing it. Results till now indicate non-linear heat transfer assisted with the occurrence of flaming transition at selected critical distances. With an increase in separation distance, the effect is noted to drop in a non-monotonic trend. The parametric study results are likely to provide useful physical insight about the governing physics and utilization in proper testing, validation, material selection, and designing of solid rocket motors with enhanced safety.

Keywords: combustion, propellant, regression, safety

Procedia PDF Downloads 144

Authors: D. Lopes, I. I. R. Baptista, R. F. Vieira, J. Vaz, H. Varela, O. M. Freitas, V. F. Domingues, R. Jorge, C. Delerue-Matos, S. A. Figueiredo

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Deodorization is nowadays a need in wastewater treatment plants. Nitrogen and sulphur compounds, volatile fatty acids, aldehydes and ketones are responsible for the unpleasant odours, being ammonia, hydrogen sulphide and mercaptans the most common pollutants. Although chemical treatments of the air extracted are efficient, these are more expensive than biological treatments, namely due the use of chemical reagents (commonly sulphuric acid, sodium hypochlorite and sodium hydroxide). Biofiltration offers the advantage of avoiding the use of reagents (only in some cases, nutrients are added in order to increase the treatment efficiency) and can be considered a sustainable process when the packing medium used is of natural origin. In this work the application of some natural materials locally available was studied both at laboratory and pilot scale, in a real wastewater treatment plant. The materials selected for this study were indigenous Portuguese forest materials derived from eucalyptus and pinewood, such as woodchips and bark, and coconut fiber was also used for comparison purposes. Their physico-chemical characterization was performed: density, moisture, pH, buffer and water retention capacity. Laboratory studies involved batch adsorption studies for ammonia and hydrogen sulphide removal and evaluation of microbiological activity. Four pilot-scale biofilters (1 cubic meter volume) were installed at a local wastewater treatment plant treating odours from the effluent receiving chamber. Each biofilter contained a different packing material consisting of mixtures of eucalyptus bark, pine woodchips and coconut fiber, with added buffering agents and nutrients. The odour treatment efficiency was monitored over time, as well as other operating parameters. The operation at pilot scale suggested that between the processes involved in biofiltration - adsorption, absorption and biodegradation - the first dominates at the beginning, while the biofilm is developing. When the biofilm is completely established, and the adsorption capacity of the material is reached, biodegradation becomes the most relevant odour removal mechanism. High odour and hydrogen sulphide removal efficiencies were achieved throughout the testing period (over 6 months), confirming the suitability of the materials selected, and mixtures thereof prepared, for biofiltration applications.

Keywords: ammonia hydrogen sulphide and removal, biofiltration, natural materials, odour control in wastewater treatment plants

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Authors: Derek Wardle, Tarik Al-Shemmeri, Neil Packer

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This paper presents a small tube/wire type electrostatic precipitator (ESP). In the ESPs present form, particle charging and collecting voltages and airflow rates were individually varied throughout 200 ambient temperature test runs ranging from 10 to 30 kV in increments on 5 kV and 0.5 m/s to 1.5 m/s, respectively. It was repeatedly observed that, at input air velocities of between 0.5 and 0.9 m/s and voltage settings of 20 kV to 30 kV, the collection efficiency remained above 95%. The outcomes of preliminary tests at combustion flue temperatures are, at present, inconclusive although indications are that there is little or no drop in comparable performance during ideal test conditions. A limited set of similar tests was carried out during which the collecting electrode was grounded, having been disconnected from the static generator. The collecting efficiency fell significantly, and for that reason, this approach was not pursued further. The collecting efficiencies during ambient temperature tests were determined by mass balance between incoming and outgoing dry PM. The efficiencies of combustion temperature runs are determined by analysing the difference in opacity of the flue gas at inlet and outlet compared to a reference light source. In addition, an array of Leit tabs (carbon coated, electrically conductive adhesive discs) was placed at inlet and outlet for a number of four-day continuous ambient temperature runs. Analysis of the discs’ contamination was carried out using scanning electron microscopy and ImageJ computer software that confirmed collection efficiencies of over 99% which gave unequivocal support to all the previous tests. The average efficiency for these runs was 99.409%. Emissions collected from a woody biomass combustion unit, classified to a diameter of 100 µm, were used in all ambient temperature trials test runs apart from two which collected airborne dust from within the laboratory. Sawdust and wood pellets were chosen for laboratory and field combustion trials. Video recordings were made of three ambient temperature test runs in which the smoke from a wood smoke generator was drawn through the precipitator. Although these runs were visual indicators only, with no objective other than to display, they provided a strong argument for the device’s claimed efficiency, as no emissions were visible at exit when energised.  The theoretical performance of ESPs, when applied to the geometry and configuration of the tested model, was compared to the actual performance and was shown to be in good agreement with it.

Keywords: electrostatic precipitators, air quality, particulates emissions, electron microscopy, image j

Procedia PDF Downloads 235

Authors: Bjornar Kjellstadli, Shaher A. I. Shalfawi

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The aim of this study was to investigate the effect of strength training Cluster set-method compared to traditional set-method 30 m sprinting time and maximum strength in squats and bench-press. Thirteen Physical Education students, 7 males and 6 females between the age of 19-28 years old were recruited. The students were random divided in three groups. Traditional set group (TSG) consist of 2 males and 2 females aged (±SD) (22.3 ± 1.5 years), body mass (79.2 ± 15.4 kg) and height (177.5 ± 11.3 cm). Cluster set group (CSG) consist of 3 males and 2 females aged (22.4 ± 3.29 years), body mass (81.0 ± 24.0 kg) and height (179.2 ± 11.8 cm) and a control group (CG) consist of 2 males and 2 females aged (21.5 ± 2.4 years), body mass (82.1 ± 17.4 kg) and height (175.5 ± 6.7 cm). The intervention consisted of performing squat and bench press at 70% of 1RM (twice a week) for 8 weeks using 10 repetition and 4 sets. Two types of strength-training methods were used , cluster set (CS) where the participants (CSG) performed 2 reps 5 times with a 10 s recovery in between reps and 50 s recovery between sets, and traditional set (TS) where the participants (TSG) performed 10 reps each set with 90 s recovery in between sets. The pre-tests and post-tests conducted were 1 RM in both squats and bench press, and 10 and 30 m sprint time. The 1RM test were performed with Eleiko XF barbell (20 kg), Eleiko weight plates, rack and bench from Hammerstrength. The speed test was measured with the Brower speed trap II testing system (Brower Timing Systems, Utah, USA). The participants received an individualized training program based on the pre-test of the 1RM. In addition, a mid-term test of 1RM was carried out to adjust training intensity. Each training session were supervised by the researchers. Beast sensors (Milano, Italy) were also used to monitor and quantify the training load for the participants. All groups had a statistical significant improvement in bench press 1RM (TSG 1RM from 56.3 ± 28.9 to 66 ± 28.5 kg; CSG 1RM from 69.8 ± 33.5 to 77.2 ± 34.1 kg and CG 1RM from 67.8 ± 26.6 to 72.2 ± 29.1 kg), whereas only the TSG (1RM from 84.3 ± 26.8 to 114.3 ± 26.5 kg) and CSG (1RM from 100.4 ± 33.9 to 129 ± 35.1 kg) had a statistical significant improvement in Squats 1RM (P < 0.05). However, a between groups examination reveals that there were no marked differences in 1RM squat performance between TSG and CSG (P > 0.05) and both groups had a marked improvements compared to the CG (P < 0.05). On the other hand, no differences between groups were observed in Bench press 1RM. The within groups results indicate that none of the groups had any marked improvement in the distances from 0-10 m and 10-30 m except the CSG which had a notable improvement in the distance from 10-30 m (-0.07 s; P < 0.05). Furthermore, no differences in sprinting abilities were observed between groups. The results from this investigation indicate that traditional set strength training at 70% of 1RM gave close results compared to Cluster set strength training at the same intensity. However, the results indicate that the cluster set had an effect on flying time (10-30 m) indicating that the velocity at which those repetitions were performed could be the explanation factor of this this improvement.

Keywords: physical performance, 1RM, pushing velocity, velocity based training

Procedia PDF Downloads 147

Authors: J. Lino Alves, L. Lopes

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It is not new that industrial design projects are a result of cooperative work from different areas of knowledge. However, in the academic teaching of Industrial Design and Mechanical Engineering courses, it is not recurrent that those competences are mixed before the professional life arrives. This abstract intends to describe two semester experiences carried out by two professors - a mechanical engineer and an industrial designer - in the last two academic years, for which they created mixed teams of Industrial Design and Mechanical Engineering (UPorto University). The two experiences differ in several factors; the main one is related to the challenges of online education, a constraint that affected the second experience. In the first year, even before foreseeing the effects that the pandemic would reconfigure the education system, a partnership with the Education Service of Águas do Porto was established. The purpose of the exercise was the project development of a game that could be an interaction element oriented to potentiate a positive experience and as an educational contribution to the children. In the second year, already foreseeing that the teaching experience would be carried out online, it was decided to design an open briefing, which allowed the groups to choose among three themes: a hand scale game using additive manufacturing; a modular system for ventilated facade using a parametric design basis; or, a modular system for vertical gardens. In methodological terms, besides the weekly follow-up, with the simultaneous support of the two professors, a group self-evaluation was requested; and a form to be filled individually to evaluate other groups. One of the first conclusions is related to the briefing format. Industrial Design students seem comfortable working on an open briefing that allows them to draw the project on a conceptual basis created for that purpose; on the other hand, Mechanical Engineering students were uncomfortable and insecure in the initial phase due to the absence of concrete, closed "order." In other words, it is not recurrent for Mechanical Engineering students that the creative component is stimulated, seemingly leaving them reserved to the technical solution and execution, depriving them of the co-creation phase during the conceptual construction of the project's own brief. Another fact that was registered is related to the leadership positions in the groups, which alternated according to the state of development of the project: design students took the lead during the ideation/concept phase, while mechanical engineering ones took a greater lead during the intermediate development process, namely in the definition of constructive solutions, mass/volume calculations, manufacturing, and material resistance. Designers' competences were again more evident and assumed in the final phase, especially in communication skills, as well as in simulations in the context of use. However, at some moments, it was visible the capacity for quite balanced leadership between engineering and design, in a constant debate centered on the human factor of the project - evidenced in the final solution, in the compromise and balance between technical constraints, functionality, usability, and aesthetics.

Keywords: education, industrial design, mechanical engineering, teaching ethodologies

Procedia PDF Downloads 158

Authors: Marlin Mubarak

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Background: Endometriosis is a complex disabling disease affecting young females in the reproductive period mainly. The aim of this project is to generate a diagnostic model to predict severity and stage of endometriosis prior to Laparoscopic surgery. This will help to improve the pre-operative diagnostic accuracy of stage 3 & 4 endometriosis and as a result, refer relevant women to a specialist centre for complex Laparoscopic surgery. The model is based on the British Society of Gynaecological Endoscopy (BSGE) pain questionnaire, clinical examination and ultrasound scan. Design: This is a prospective, observational, study, in which women completed the BSGE pain questionnaire, a BSGE requirement. Also, as part of the routine preoperative assessment patient had a routine ultrasound scan and when recto-vaginal and deep infiltrating endometriosis was suspected an MRI was performed. Setting: Luton & Dunstable University Hospital. Patients: Symptomatic women (n = 56) scheduled for laparoscopy due to pelvic pain. The age ranged between 17 – 52 years of age (mean 33.8 years, SD 8.7 years). Interventions: None outside the recognised and established endometriosis centre protocol set up by BSGE. Main Outcome Measure(s): Sensitivity and specificity of endometriosis diagnosis predicted by symptoms based on BSGE pain questionnaire, clinical examinations and imaging. Findings: The prevalence of diagnosed endometriosis was calculated to be 76.8% and the prevalence of advanced stage was 55.4%. Deep infiltrating endometriosis in various locations was diagnosed in 32/56 women (57.1%) and some had DIE involving several locations. Logistic regression analysis was performed on 36 clinical variables to create a simple clinical prediction model. After creating the scoring system using variables with P < 0.05, the model was applied to the whole dataset. The sensitivity was 83.87% and specificity 96%. The positive likelihood ratio was 20.97 and the negative likelihood ratio was 0.17, indicating that the model has a good predictive value and could be useful in predicting advanced stage endometriosis. Conclusions: This is a hypothesis-generating project with one operator, but future proposed research would provide validation of the model and establish its usefulness in the general setting. Predictive tools based on such model could help organise the appropriate investigation in clinical practice, reduce risks associated with surgery and improve outcome. It could be of value for future research to standardise the assessment of women presenting with pelvic pain. The model needs further testing in a general setting to assess if the initial results are reproducible.

Keywords: deep endometriosis, endometriosis, minimally invasive, MRI, ultrasound.

Procedia PDF Downloads 331

Authors: Brad Stappenbelt

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The phenomenon of vortex-induced vibration (VIV) for elastically restrained cylindrical structures in cross-flows is relatively well investigated. The utility of this mechanism in harvesting energy from marine current and tidal flows is however arguably still in its infancy. With relatively few moving components, a flow-induced vibration-based energy conversion device augers low complexity compared to the commonly employed turbine design. Despite the interest in this concept, a practical device has yet to emerge. It is desirable for optimal system performance to design for a very low mass or mass moment of inertia ratio. The device operating range, in particular, is maximized below the vortex-induced vibration critical point where an infinite resonant response region is realized. An unfortunate consequence of this requirement is large buoyancy forces that need to be mitigated by gravity-based, suction-caisson or anchor mooring systems. The focus of this paper is the testing of a novel VIV marine current energy harvesting configuration that utilizes a symmetrical and balanced pair of horizontal pivoted cylinders. The results of several years of experimental investigation, utilizing the University of Wollongong fluid mechanics laboratory towing tank, are analyzed and presented. A reduced velocity test range of 0 to 60 was covered across a large array of device configurations. In particular, power take-off damping ratios spanning from 0.044 to critical damping were examined in order to determine the optimal conditions and hence the maximum device energy conversion efficiency. The experiments conducted revealed acceptable energy conversion efficiencies of around 16% and desirable low flow-speed operating ranges when compared to traditional turbine technology. The potentially out-of-phase spanwise VIV cells on each arm of the device synchronized naturally as no decrease in amplitude response and comparable energy conversion efficiencies to the single cylinder arrangement were observed. In addition to the spatial design benefits related to the horizontal device orientation, the main advantage demonstrated by the current symmetrical horizontal configuration is to allow large velocity range resonant response conditions without the excessive buoyancy. The novel configuration proposed shows clear promise in overcoming many of the practical implementation issues related to flow-induced vibration marine current energy harvesting.

Keywords: flow-induced vibration, vortex-induced vibration, energy harvesting, tidal energy

Procedia PDF Downloads 132

Authors: H. M. El-Askary, S. A. Abd El-Mawla, M. Allali, M. M. El-Hattab, M. El-Raey, A. M. Farahat, M. Kafatos, S. Nickovic, S. K. Park, A. K. Prasad, C. Rakovski, W. Sprigg, D. Struppa, A. Vukovic

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A clear distinction between weather and climate is a necessity because while they are closely related, there are still important differences. Climate change is identified when we compute the statistics of the observed changes in weather over space and time. In this work we will show how the changing climate contribute to the frequency, magnitude and extent of different extreme events using a multi sensor approach with some synergistic modeling activities. We are exploring satellite observations of dust over North Africa, Gulf Region and the Indo Gangetic basin as well as dust versus anthropogenic pollution events over the Delta region in Egypt and Seoul through remote sensing and utilize the behavior of the dust and haze on the aerosol optical properties. Dust impact on the retreat of the glaciers in the Himalayas is also presented. In this study we also focus on the identification and monitoring of a massive dust plume that blew off the western coast of Africa towards the Atlantic on October 8th, 2012 right before the development of Hurricane Sandy. There is evidence that dust aerosols played a non-trivial role in the cyclogenesis process of Sandy. Moreover, a special dust event "An American Haboob" in Arizona is discussed as it was predicted hours in advance because of the great improvement we have in numerical, land–atmosphere modeling, computing power and remote sensing of dust events. Therefore we performed a full numerical simulation to that event using the coupled atmospheric-dust model NMME–DREAM after generating a mask of the potentially dust productive regions using land cover and vegetation data obtained from satellites. Climate change also contributes to the deterioration of different marine habitats. In that regard we are also presenting some work dealing with change detection analysis of Marine Habitats over the city of Hurghada, Red Sea, Egypt. The motivation for this work came from the fact that coral reefs at Hurghada have undergone significant decline. They are damaged, displaced, polluted, stepped on, and blasted off, in addition to the effects of climate change on the reefs. One of the most pressing issues affecting reef health is mass coral bleaching that result from an interaction between human activities and climatic changes. Over another location, namely California, we have observed that it exhibits highly-variable amounts of precipitation across many timescales, from the hourly to the climate timescale. Frequently, heavy precipitation occurs, causing damage to property and life (floods, landslides, etc.). These extreme events, variability, and the lack of good, medium to long-range predictability of precipitation are already a challenge to those who manage wetlands, coastal infrastructure, agriculture and fresh water supply. Adding on to the current challenges for long-range planning is climate change issue. It is known that La Niña and El Niño affect precipitation patterns, which in turn are entwined with global climate patterns. We have studied ENSO impact on precipitation variability over different climate divisions in California. On the other hand the Nile Delta has experienced lately an increase in the underground water table as well as water logging, bogging and soil salinization. Those impacts would pose a major threat to the Delta region inheritance and existing communities. There has been an undergoing effort to address those vulnerabilities by looking into many adaptation strategies.

Keywords: remote sensing, modeling, long range transport, dust storms, North Africa, Gulf Region, India, California, climate extremes, sea level rise, coral reefs

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Authors: Zipeng Zhang, Yat C. Wong, Arul Arulrajah

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Since automobiles became widely popular around the early 20th century, end-of-life tyres have been one of the major types of waste humans encounter. Every minute, there are considerable quantities of tyres being disposed of around the world. Most end-of-life tyres are simply landfilled or simply stockpiled, other than recycling. To address the potential issues caused by tyre waste, incorporating it into construction materials can be a possibility. This research investigated the viability of manufacturing bricks using mill waste and tyre crumb by alkali-activation at a relatively low temperature. The mill waste was extracted from a brick factory located in Melbourne, Australia, and the tyre crumbs were supplied by a local recycling company. As the main precursor, the mill waste was activated by the alkaline solution, which was comprised of sodium hydroxide (8m) and sodium silicate (liquid). The introduction ratio of alkaline solution (relative to the solid weight) and the weight ratio between sodium hydroxide and sodium silicate was fixed at 20 wt.% and 1:1, respectively. The tyre crumb was introduced to substitute part of the mill waste at four ratios by weight, namely 0, 5, 10 and 15%. The mixture of mill waste and tyre crumbs were firstly dry-mixed for 2 min to ensure the homogeneity, followed by a 2.5-min wet mixing after adding the solution. The ready mixture subsequently was press-moulded into blocks with the size of 109 mm in length, 112.5 mm in width and 76 mm in height. The blocks were cured at 50°C with 95% relative humidity for 2 days, followed by a 110°C oven-curing for 1 day. All the samples were then placed under the ambient environment until the age of 7 and 28 days for testing. A series of tests were conducted to evaluate the linear shrinkage, compressive strength and water absorption of the samples. In addition, the microstructure of the samples was examined via the scanning electron microscope (SEM) test. The results showed the highest compressive strength was 17.6 MPa, found in the 28-day-old group using 5 wt.% tyre crumbs. Such strength has been able to satisfy the requirement of ASTM C67. However, the increasing addition of tyre crumb weakened the compressive strength of samples. Apart from the strength, the linear shrinkage and water absorption of all the groups can meet the requirements of the standard. It is worth noting that the use of tyre crumbs tended to decrease the shrinkage and even caused expansion when the tyre content was over 15 wt.%. The research also found that there was a significant reduction in compressive strength for the samples after water absorption tests. In conclusion, the tyre crumbs have the potential to be used as a filler material in brick manufacturing, but more research needs to be done to tackle the durability problem in the future.

Keywords: bricks, mill waste, tyre crumbs, waste recycling

Procedia PDF Downloads 104

Authors: Abdul Haq

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The goal of this research is to better understand how wind loads affect bridges and develop strategies for designing bridges that are more stable and resistant to wind. The effect of wind on bridges is essential to their safety and functionality, especially in areas that are prone to high wind speeds or violent wind conditions. The study looks at the aerodynamic forces and vibrations caused by wind and how they affect bridge construction. Part of the research method involves first understanding the underlying ideas influencing wind flow near bridges. Computational fluid dynamics (CFD) simulations are used to model and forecast the aerodynamic behaviour of bridges under different wind conditions. These models incorporate several factors, such as wind directionality, wind speed, turbulence intensity, and the influence of nearby structures or topography. The results provide significant new insights into the loads and pressures that wind places on different bridge elements, such as decks, pylons, and connections. Following the determination of the wind loads, the structural response of bridges is assessed. By simulating their dynamic behavior under wind-induced forces, Finite Element Analysis (FEA) is used to model the bridge's component parts. This work contributes to the understanding of which areas are at risk of experiencing excessive stresses, vibrations, or oscillations due to wind excitations. Because the bridge has inherent modes and frequencies, the study considers both static and dynamic responses. Various strategies are examined to maximize the design of bridges to withstand wind. It is possible to alter the bridge's geometry, add aerodynamic components, add dampers or tuned mass dampers to lessen vibrations, and boost structural rigidity. Through an analysis of several design modifications and their effectiveness, the study aims to offer guidelines and recommendations for wind-resistant bridge design. In addition to the numerical simulations and analyses, there are experimental studies. In order to assess the computational models and validate the practicality of proposed design strategies, scaled bridge models are tested in a wind tunnel. These investigations help to improve numerical models and prediction precision by providing valuable information on wind-induced forces, pressures, and flow patterns. Using a combination of numerical models, actual testing, and long-term performance evaluation, the project aims to offer practical insights and recommendations for building wind-resistant bridges that are secure, long-lasting, and comfortable for users.

Keywords: wind effects, aerodynamic forces, computational fluid dynamics, finite element analysis

Procedia PDF Downloads 47

Authors: Ying Li, Rui Hu, Shizhen Chen, Xin Zhou, Yunhuang Yang

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Prostate cancer is one of the leading causes of cancer-related death among men. Prostate-specific antigen (PSA), a specific product of prostatic epithelial cells, is an important indicator of prostate cancer. Though PSA is not a specific serum biomarker for the screening of prostate cancer, it is recognized as an indicator for prostate cancer recurrence and response to therapy for patient’s post-prostatectomy. Since radical prostatectomy eliminates the source of PSA production, serum PSA levels fall below 50 pg/mL, and may be below the detection limit of clinical immunoassays (current clinical immunoassay lower limit of detection is around 10 pg/mL). Many clinical studies have shown that intervention at low PSA levels was able to improve patient outcomes significantly. Therefore, ultra-sensitive and precise assays that can accurately quantify extremely low levels of PSA (below 1-10 pg/mL) will facilitate the assessment of patients for the possibility of early adjuvant or salvage treatment. Currently, the commercially available ultra-sensitive ELISA kit (not used clinically) can only reach a detection limit of 3-10 pg/mL. Other platforms developed by different research groups could achieve a detection limit as low as 0.33 pg/mL, but they relied on sophisticated instruments to get the final readout. Herein we report a microfluidic platform for point-of-care (POC) detection of PSA with a detection limit of 0.5 pg/mL and without the assistance of any equipment. This platform is based on a previously reported volumetric-bar-chart chip (V-Chip), which applies platinum nanoparticles (PtNPs) as the ELISA probe to convert the biomarker concentration to the volume of oxygen gas that further pushes the red ink to form a visualized bar-chart. The length of each bar is used to quantify the biomarker concentration of each sample. We devised a long reading channel V-Chip (LV-Chip) in this work to achieve a wide detection window. In addition, LV-Chip employed a unique enzyme-free ELISA probe that enriched PtNPs significantly and owned 500-fold enhanced catalytic ability over that of previous V-Chip, resulting in a significantly improved detection limit. LV-Chip is able to complete a PSA assay for five samples in 20 min. The device was applied to detect PSA in 50 patient serum samples, and the on-chip results demonstrated good correlation with conventional immunoassay. In addition, the PSA levels in finger-prick whole blood samples from healthy volunteers were successfully measured on the device. This completely stand-alone LV-Chip platform enables convenient POC testing for patient follow-up in the physician’s office and is also useful in resource-constrained settings.

Keywords: point-of-care detection, microfluidics, PSA, ultra-sensitive

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Authors: Valeria Velasco, Ana M. Bonilla, José L. Vergara, Alcides Lofa, Jorge Campos, Pedro Rojas-García

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Staphylococcus aureus is both commensal bacterium and opportunistic pathogen that can cause different diseases in humans and can rapidly develop antimicrobial resistance. Since this bacterium has the ability to colonize the nares and skin of humans and animals, there is a risk of contamination of food in different steps of the food chain supply. Emerging strains have been detected in food-producing animals and meat, such as methicillin-resistant S. aureus (MRSA). The aim of this study was to determine the prevalence and oxacillin susceptibility of S. aureus in the pork chain supply in Chile and to suggest some natural antimicrobials for control. A total of 487 samples were collected from pigs (n=332), carcasses (n=85), and retail pork meat (n=70). Presumptive S. aureus colonies were isolated by selective enrichment and culture media. The confirmation was carried out by biochemical testing (Api® Staph) and molecular technique PCR (detection of nuc and mecA genes, associated with S. aureus and methicillin resistance, respectively). The oxacillin (β-lactam antibiotic that replaced methicillin) susceptibility was assessed by minimum inhibitory concentration (MIC) using the Epsilometer test (Etest). A preliminary assay was carried out to test thymol, carvacrol, oregano essential oil (Origanum vulgare L.), Maqui or Chilean wineberry extract (Aristotelia chilensis (Mol.) Stuntz) as anti-staphylococcal agents using the disc diffusion method at different concentrations. The overall prevalence of S. aureus in the pork chain supply reached 33.9%. A higher prevalence of S. aureus was determined in carcasses (56.5%) than in pigs (28.3%) and pork meat (32.9%) (P ≤ 0.05). The prevalence of S. aureus in pigs sampled at farms (40.6%) was higher than in pigs sampled at slaughterhouses (23.3%) (P ≤ 0.05). The contamination of no packaged meat with S. aureus (43.1%) was higher than in packaged meat (5.3%) (P ≤ 0.05). The mecA gene was not detected in S. aureus strains isolated in this study. Two S. aureus strains exhibited oxacillin resistance (MIC ≥ 4µg/mL). Anti-staphylococcal activity was detected in solutions of thymol, carvacrol, and oregano essential oil at all concentrations tested. No anti-staphylococcal activity was detected in Maqui extract. Finally, S. aureus is present in the pork chain supply in Chile. Although the mecA gene was not detected, oxacillin resistance was found in S. aureus and could be attributed to another resistance mechanism. Thymol, carvacrol, and oregano essential oil could be used as anti-staphylococcal agents at low concentrations. Research project Fondecyt No. 11140379.

Keywords: antimicrobials, mecA gen, nuc gen, oxacillin susceptibility, pork meat

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Authors: Deanne McArthur, Melinda Wall, Claire Hanlon, Dana Agnolin, Krista Davis, Melanie Dennis, Elizabeth Glidden, Anne Marie Smith, Claudette Thomson

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In Canada, as prevalence rates and severity of illness have increased among patients suffering from eating disorders, wait times have grown substantially. Patients in Canada often face wait times in excess of 12 months. It is known that delaying treatment for eating disorders contributes to poor patient outcomes and higher rates of symptom relapse. Improving interim services for adult patients awaiting outpatient treatment is a priority for an outpatient eating disorders clinic in Ontario, Canada. The clinical setting currently provides care for adults diagnosed with anorexia nervosa, bulimia nervosa and binge eating disorder. At present, the only support provided while patients are on the waitlist consists of communication with primary care providers regarding parameters for medical monitoring. The significance of this study will be to test the feasibility, acceptability and efficacy of an intervention to support adult patients awaiting outpatient eating disorder treatment for anorexia nervosa, bulimia nervosa and binge eating disorder. Methods: An intervention including psychoeducation, supportive resources, self-monitoring, and auxiliary referral will be pilot-tested with a group of patients in the summer of 2022 and detailed using a prospective cohort case study research design. The team will host patient focus groups in May 2022 to gather input informing the content of the intervention. The intervention will be pilot tested with newly-referred patients in June and July 2022. Patients who participate in the intervention will be asked to complete a survey evaluating the utility of the intervention and for suggestions, they may have for improvement. Preliminary findings describing the existing literature pertaining to waitlist interventions for patients with eating disorders, data gathered from the focus groups and early pilot testing results will be presented. Data analysis will continue throughout 2022 and early 2023 for follow-up publication and presentation in the summer of 2023. The aim of this study is to contribute to the body of knowledge pertaining to providing interim support to those patients waiting for treatment for eating disorders and, by extension, to improve outcomes for this population.

Keywords: eating disorders, waitlist management, intervention study, pilot test

Procedia PDF Downloads 79

Authors: Mishadi Herath, Amin Talei, Andreas Hermawan, Clarina Chua

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Green walls are vegetated structures on building’s wall that are considered as part of sustainable urban design. They are proved to have many micro-climate benefits such as reduction in indoor temperature, noise attenuation, and improvement in air quality. On the other hand, several studies have also been conducted on potential reuse of greywater in urban water management. Greywater is relatively clean when compared to blackwater; therefore, this study was aimed to assess the potential reuse of it for irrigating a green wall system. In this study, the campus of Monash University Malaysia located in Selangor state was considered as the study site where total 48 samples of greywater were collected from 7 toilets hand-wash and 5 pantries during 3 months period. The samples were tested to characterize the quality of greywater in the study site and compare it with local standard for irrigation water. PH and concentration of heavy metals, nutrients, Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), total Coliform and E.coli were measured. Results showed that greywater could be directly used for irrigation with minimal treatment. Since the effluent of the system was supposed to be drained to stormwater drainage system, the effluent needed to meet certain quality requirement. Therefore, a biofiltration system was proposed to host the green wall plants and also treat the greywater (which is used as irrigation water) to the required level. To assess the performance of the proposed system, an experimental setup consisting of Polyvinyl Chloride (PVC) soil columns with sand-based filter media were prepared. Two different local creeper plants were chosen considering several factors including fast growth, low maintenance requirement, and aesthetic aspects. Three replicates of each plants were used to ensure the validity of the findings. The growth of creeping plants and their survivability was monitored for 6 months while monthly sampling and testing of effluent was conducted to evaluate effluent quality. An analysis was also conducted to estimate the potential cost and benefit of such system considering water and energy saving in the system. Results showed that the proposed system can work efficiently throughout a long period of time with minimal maintenance requirement. Moreover, the biofiltration-green wall system was found to be successful in reusing greywater as irrigating water while the effluent was meeting all the requirements for being drained to stormwater drainage system.

Keywords: biofiltration, green wall, greywater, sustainability

Procedia PDF Downloads 197

Authors: Laura Canagueral-Pellice, Antonio Munar-Frau, Adaia Valls-Ontanon, Joao Carames, Federico Hernandez-Alfaro, Jordi Caballe-Serrano

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Objective: Guided bone regeneration (GBR) aims to replace the missing bone with a new structure to achieve long-term stability of rehabilitations. The aim of the present systematic review and meta-analysis is to determine the effect of barrier membranes on histological outcomes after GBR procedures. Moreover, the effect of the grafting material and tissue gain were analyzed. Materials & methods: Two independent reviewers performed an electronic search in Pubmed and Scopus, identifying all eligible publications up to March 2020. Only randomized controlled trials (RCTs) assessing a histological analysis of augmented areas were included. Results: A total of 6 publications were included for the present systematic review. A total of 110 biopsied sites were analysed; 10 corresponded to vertical bone augmentation procedures, whereas 100 analysed horizontal regeneration procedures. A mean tissue gain of 3 ± 1.48mm was obtained for horizontal defects. Histological assessment of new bone formation, residual particle and sub-epithelial connective tissue (SCT) was reported. The four main barrier membranes used were natural collagen membranes, e-PTFE, polylactic resorbable membranes and acellular dermal matrix membranes (AMDG). The analysis demonstrated that resorbable membranes result in higher values of new bone formation and lower values of residual particles and SCT. Xenograft resulted in lower new bone formation compared to allograft; however, no statistically significant differences were observed regarding residual particle and SCT. Overall, regeneration procedures adding autogenous bone, plasma derivate or growth factors achieved in general greater new bone formation and tissue gain. Conclusions: There is limited evidence favoring the effect of a certain type of barrier membrane in GBR. Data needs to be evaluated carefully; however, resorbable membranes are correlated with greater new bone formation values, especially when combined with allograft materials and/or the addition of autogenous bone, platelet reach plasma (PRP) or growth factors in the regeneration area. More studies assessing the histological outcomes of different GBR protocols and procedures testing different biomaterials are needed to maximize the clinical and histological outcomes in bone regeneration science.

Keywords: barrier membrane, graft material, guided bone regeneration, implant surgery, histology

Procedia PDF Downloads 134

Authors: Mo'ath F. Bataineh

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Exercise is highly effective against obesity. Milk contains several components that support exercising and physical performance. However, there is a lack of published studies on the relationship between camel milk and ability to exercise. A pilot study was conducted with the purpose of comparing the impact of milk type (Cow vs Camel) compared with water on physical performance. Seven male obese participants (age: 20.3 ± 1.5 years; BMI: 35.7 ± 2.7 kg/m2; resting heart rate: 92.7 ± 4.7 beats per minute; training frequency: 4.4 ± 0.8 days/week) were recruited for this pilot study. In a randomized counterbalanced crossover design, participants took part in 3 trials that included ingesting 3 different pre workout drinks in a random order. The pre workout drinks were water (W), whole cow milk (CW), and whole camel milk (CM). On each trial day, participants were asked to report to the laboratory after an overnight fasting. Following a 15-minute short recovery period after their arrival to the laboratory, each participant was presented with a 500 ml of the assigned experimental drink and were asked to ingest it in one minute and at least 120 minutes prior to performing the 6-minute walk test. All drinks were presented at room temperature. Trials with different experimental drinks were performed on separate days. Participants were given at least 4 days of washout period between trials. The trial order was randomized to avoid bias due to learning effect. The 6-minute walk test was performed by all participants and immediately at the conclusion of the test, the covered distance in meters and the rating of perceived exertion (RPE) were recorded. All data were analysed using SPSS software (Version 29.0). The repeated measures ANOVA testing of collected data showed a significant main effect for treatment on covered distance in meters, F (2, 8) = 5.794, p=0.028 with a large effect size (partial eta squared (ηp2) =0.592). Also, LSD post hoc pairwise comparison analysis revealed that Camel milk and Cow milk were significantly (p = 0.044 and p = 0.020 respectively) superior to water in improving the covered distance during the test and that Camel milk tended to be better than Cow’s milk. The RPE values were not significantly different between experimental drinks (p>0.05). In conclusion, milk is superior to water as a pre workout drink, and camel milk is comparable to cow’s milk in enhancing ability to support a higher level of performance compared with water, therefore, camel milk could be used to replace cow’s milk as a suitable pre-exercise drink without expecting any negative consequences on physical performance. The fact that these positive results were obtained with obese individuals should encourage using camel milk without the fear of disturbing physical performance in other weight categories.

Keywords: camel milk, cow milk, obesity, physical performance, pre-workout drink

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Authors: Netasha Shaikh, Bryony Wood, Demitra Tsivos, Michael Knight, Risto Kauppinen, Elizabeth Coulthard

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Background: Effective treatment of dementia will require early diagnosis, before significant brain damage has accumulated. Memory loss is an early symptom of Alzheimer’s disease (AD). The hippocampus, a brain area critical for memory, degenerates early in the course of AD. The hippocampus comprises several subfields. In contrast to healthy aging where CA3 and dentate gyrus are the hippocampal subfields with most prominent atrophy, in AD the CA1 and subiculum are thought to be affected early. Conventional clinical structural neuroimaging is not sufficiently sensitive to identify preferential atrophy in individual subfields. Here, we will explore the sensitivity of new magnetic resonance imaging (MRI) sequences designed to interrogate medial temporal regions as an early marker of Alzheimer’s. As it is likely a combination of tests may predict early Alzheimer’s disease (AD) better than any single test, we look at the potential efficacy of such imaging alone and in combination with standard and novel cognitive tasks of hippocampal dependent memory. Methods: 20 patients with mild cognitive impairment (MCI), 20 with mild-moderate AD and 20 age-matched healthy elderly controls (HC) are being recruited to undergo 3T MRI (with sequences designed to allow volumetric analysis of hippocampal subfields) and a battery of cognitive tasks (including Paired Associative Learning from CANTAB, Hopkins Verbal Learning Test and a novel hippocampal-dependent abstract word memory task). AD participants and healthy controls are being tested just once whereas patients with MCI will be tested twice a year apart. We will compare subfield size between groups and correlate subfield size with cognitive performance on our tasks. In the MCI group, we will explore the relationship between subfield volume, cognitive test performance and deterioration in clinical condition over a year. Results: Preliminary data (currently on 16 participants: 2 AD; 4 MCI; 9 HC) have revealed subfield size differences between subject groups. Patients with AD perform with less accuracy on tasks of hippocampal-dependent memory, and MCI patient performance and reaction times also differ from healthy controls. With further testing, we hope to delineate how subfield-specific atrophy corresponds with changes in cognitive function, and characterise how this progresses over the time course of the disease. Conclusion: Novel sequences on a MRI scanner such as those in route in clinical use can be used to delineate hippocampal subfields in patients with and without dementia. Preliminary data suggest that such subfield analysis, perhaps in combination with cognitive tasks, may be an early marker of AD.

Keywords: Alzheimer's disease, dementia, memory, cognition, hippocampus

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Authors: Anil Saini, Jatinder Kumar Ratan

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Now a day, the key issue for the scientific community is to devise the innovative technologies for sustainable control of urban pollution. In urban cities, a large surface area of the masonry structures, buildings, and pavements is exposed to the open environment, which may be utilized for the control of air pollution, if it is built from the photocatalytically active cement-based constructional materials such as concrete, mortars, paints, and blocks, etc. The photocatalytically active cement is formulated by incorporating a photocatalyst in the cement matrix, and such cement is generally known as self-cleaning cement In the literature, self-cleaning cement has been synthesized by incorporating nanosized-TiO₂ (n-TiO₂) as a photocatalyst in the formulation of the cement. However, the utilization of n-TiO₂ for the formulation of self-cleaning cement has the drawbacks of nano-toxicity, higher cost, and agglomeration as far as the commercial production and applications are concerned. The use of microsized-TiO₂ (m-TiO₂) in place of n-TiO₂ for the commercial manufacture of self-cleaning cement could avoid the above-mentioned problems. However, m-TiO₂ is less photocatalytically active as compared to n- TiO₂ due to smaller surface area, higher band gap, and increased recombination rate. As such, the use of m-TiO₂ in the formulation of self-cleaning cement may lead to a reduction in photocatalytic activity, thus, reducing the self-cleaning, depolluting, and antimicrobial abilities of the resultant cement material. So improvement in the photoactivity of m-TiO₂ based self-cleaning cement is the key issue for its practical applications in the present scenario. The current work proposes the use of surface-fluorinated m-TiO₂ for the formulation of self-cleaning cement to enhance its photocatalytic activity. The calcined dolomite, a constructional material, has also been utilized as co-adsorbent along with the surface-fluorinated m-TiO₂ in the formulation of self-cleaning cement to enhance the photocatalytic performance. The surface-fluorinated m-TiO₂, calcined dolomite, and the formulated self-cleaning cement were characterized using diffuse reflectance spectroscopy (DRS), X-ray diffraction analysis (XRD), field emission-scanning electron microscopy (FE-SEM), energy dispersive x-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), BET (Brunauer–Emmett–Teller) surface area, and energy dispersive X-ray fluorescence spectrometry (EDXRF). The self-cleaning property of the as-prepared self-cleaning cement was evaluated using the methylene blue (MB) test. The depolluting ability of the formulated self-cleaning cement was assessed through a continuous NOX removal test. The antimicrobial activity of the self-cleaning cement was appraised using the method of the zone of inhibition. The as-prepared self-cleaning cement obtained by uniform mixing of 87% clinker, 10% calcined dolomite, and 3% surface-fluorinated m-TiO₂ showed a remarkable self-cleaning property by providing 53.9% degradation of the coated MB dye. The self-cleaning cement also depicted a noteworthy depolluting ability by removing 5.5% of NOx from the air. The inactivation of B. subtiltis bacteria in the presence of light confirmed the significant antimicrobial property of the formulated self-cleaning cement. The self-cleaning, depolluting, and antimicrobial results are attributed to the synergetic effect of surface-fluorinated m-TiO₂ and calcined dolomite in the cement matrix. The present study opens an idea and route for further research for acile and economical formulation of self-cleaning cement.

Keywords: microsized-titanium dioxide (m-TiO₂), self-cleaning cement, photocatalysis, surface-fluorination

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Authors: Sylvie Michel, Sylvie Gerbaix, Marc Bidan

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The COVID-19 pandemic has been a major and global disruption that has affected all supply chains on a worldwide scale. Consequently, the question posed by this communication is to understand how - in the face of such disruptions - supply chains, including their actors, management tools, and processes, react, survive, adapt, and even improve. To do so, the concepts of resilience and antifragility applied to a supply chain have been leveraged. This article proposes to perceive resilience as a step to surpass in moving towards antifragility. The research objective is to propose an analytical framework to measure and compare resilience and antifragility, with antifragility seen as a property of a system that improves when subjected to disruptions rather than merely resisting these disruptions, as is the case with resilience. A unique case study was studied - MSF logistics (France) - using a qualitative methodology. Semi-structured interviews were conducted in person and remotely in multiple phases: during and immediately after the COVID crisis (8 interviews from March 2020 to April 2021), followed by a new round from September to November 2023. A Delphi method was employed. The interviews were analyzed using coding and a thematic framework. One of the theoretical contributions is consolidating the field of supply chain resilience research by precisely characterizing the dimensions of resilience for a humanitarian supply chain (Reorganization, Collaboration mediated by IS, Humanitarian culture). In this regard, a managerial contribution of this study is providing a guide for managers to identify the four dimensions and sub-dimensions of supply chain resilience. This enables managers to focus their decisions and actions on dimensions that will enhance resilience. Most importantly, another contribution is comparing the concepts of resilience and antifragility and proposing an analytical framework for antifragility—namely, the mechanisms on which MSF logistics relied to capitalize on uncertainties, contingencies, and shocks rather than simply enduring them. For MSF Logistics, antifragility manifested through the ability to identify opportunities hidden behind the uncertainties and shocks of COVID-19, reducing vulnerability, and fostering a culture that encourages innovation and the testing of new ideas. Logistics, particularly in the humanitarian domain, must be able to adapt to environmental disruptions. In this sense, this study identifies and characterizes the dimensions of resilience implemented by humanitarian logistics. Moreover, this research goes beyond the concept of resilience to propose an analytical framework for the concept of antifragility. The organization studied emerged stronger from the COVID-19 crisis due to the mechanisms we identified, allowing us to characterize antifragility. Finally, the results show that the information system plays a key role in antifragility.

Keywords: antifragility, humanitarian supply chain, information systems, qualitative research, resilience.

Procedia PDF Downloads 49

Authors: Ming-Hsiang Shih, Wen-Pei Sung, Shih-Heng Tung

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Semi-active control system for structure under excitation of earthquake provides with the characteristics of being adaptable and requiring low energy. DSHD (Displacement Semi-Active Hydraulic Damper) was developed by our research team. Shake table test results of this DSHD installed in full scale test structure demonstrated that this device brought its energy-dissipating performance into full play for test structure under excitation of earthquake. The objective of this research is to develop a new AIC (Active Interaction Control Device) and apply shake table test to perform its dissipation of energy capability. This new proposed AIC is converting an improved DSHD (Displacement Semi-Active Hydraulic Damper) to AIC with the addition of an accumulator. The main concept of this energy-dissipating AIC is to apply the interaction function of affiliated structure (sub-structure) and protected structure (main structure) to transfer the input seismic force into sub-structure to reduce the structural deformation of main structure. This concept is tested using full-scale multi-degree of freedoms test structure, installed with this proposed AIC subjected to external forces of various magnitudes, for examining the shock absorption influence of predictive control, stiffness of sub-structure, synchronous control, non-synchronous control and insufficient control position. The test results confirm: (1) this developed device is capable of diminishing the structural displacement and acceleration response effectively; (2) the shock absorption of low precision of semi-active control method did twice as much seismic proof efficacy as that of passive control method; (3) active control method may not exert a negative influence of amplifying acceleration response of structure; (4) this AIC comes into being time-delay problem. It is the same problem of ordinary active control method. The proposed predictive control method can overcome this defect; (5) condition switch is an important characteristics of control type. The test results show that synchronism control is very easy to control and avoid stirring high frequency response. This laboratory results confirm that the device developed in this research is capable of applying the mutual interaction between the subordinate structure and the main structure to be protected is capable of transforming the quake energy applied to the main structure to the subordinate structure so that the objective of minimizing the deformation of main structural can be achieved.

Keywords: DSHD (Displacement Semi-Active Hydraulic Damper), AIC (Active Interaction Control Device), shake table test, full scale structure test, sub-structure, main-structure

Procedia PDF Downloads 501

Authors: R. Pussinen, V. Jankovic, U. Herzberg, M. Cerrada-Gimenez, T. Huhtala, A. Nurmi, T. Ahtoniemi

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Targeted over-expression of human α-synuclein using viral-vector mediated gene delivery into the substantia nigra of rats and non-human primates has been reported to lead to dopaminergic cell loss and the formation of α-synuclein aggregates reminiscent of Lewy bodies. We have previously shown how AAV-mediated expression of α-synuclein is seen in the chronic phenotype of the rats over 16 week follow-up period. In the context of these findings, we attempted to further characterize this long term PD related functional and motor deficits as well as neurochemical and neuropathological changes in AAV-mediated α-synuclein transfection model in rats during chronic follow-up period. Different titers of recombinant AAV expressing human α-synuclein (A53T) were stereotaxically injected unilaterally into substantia nigra of Wistar rats. Rats were allowed to recover for 3 weeks prior to initial baseline behavioral testing with rotational asymmetry test, stepping test and cylinder test. A similar behavioral test battery was applied again at weeks 5, 9,12 and 15. In addition to traditionally used rat PD model tests, MotoRater test system, a high speed kinematic gait performance monitoring was applied during the follow-up period. Evaluation focused on animal gait between groups. Tremor analysis was performed on weeks 9, 12 and 15. In addition to behavioral end-points, neurochemical evaluation of dopamine and its metabolites were evaluated in striatum. Furthermore, integrity of the dopamine active transport (DAT) system was evaluated by using 123I- β-CIT and SPECT/CT imaging on weeks 3, 8 and 12 after AAV- α-synuclein transfection. Histopathology was examined from end-point samples at 3 or 12 weeks after AAV- α-synuclein transfection to evaluate dopaminergic cell viability and microglial (Iba-1) activation status in substantia nigra by using stereological analysis techniques. This study focused on the characterization and validation of previously published AAV- α-synuclein transfection model in rats but with the addition of novel end-points. We present the long term phenotype of AAV- α-synuclein transfected rats with traditionally used behavioral tests but also by using novel fine motor analysis techniques and tremor analysis which provide new insight to unilateral effects of AAV α-synuclein transfection. We also present data about neurochemical and neuropathological end-points for the dopaminergic system in the model and how well they correlate with behavioral phenotype.

Keywords: adeno-associated virus, alphasynuclein, animal model, Parkinson’s disease

Procedia PDF Downloads 278

Authors: Adam Aboalkaz, Rana Shamoon, Duncan Meikle, James Lewis

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Background and aims: In orthopaedic theatres, radiological screening during operations is a commonly used and useful technique to visualise and guide the operating surgeon. Within any theatre using ionising radiation, it is imperative that the use of protective equipment and the wearing of a dosimeter at all times. 1. To assess compliance with use of protective equipment during orthopaedic procedures involving ionising radiation. 2. To assess the radiation risk knowledge of staff members regularly present in an orthopaedic theatre of a national major trauma centre, in accordance to the ionising radiation regulation (2000) guidelines. Method: We conducted an Observational study of 21 operations at the University Hospital of Wales, which is a major trauma centre, recording the compliance with use of protective equipment (lead aprons and thyroid shields) and dosimeters. The observations were performed sporadically over a two week period to ensure that all staff in monitored operating theatres were not aware of the ongoing study, as to avoid bias. A questionnaire testing the knowledge of trainees and staff within the orthopaedic department was given following completion of the initial phase of the study, with 19 responses. The questions were based on knowledge of ionising radiation exposure and monitoring. The questions also tested the general staff knowledge of what equipment should be worn and where to locate such equipment. Results: This study found that only 25% of staff members were wearing thyroid protectors when less than 1 meter from the radiation source and only 50% were wearing appropriate lead aprons whilst in this same vicinity. The study also showed that 0% of all staff members used a dosimeter whilst in an area of radiation exposure. From the distributed questionnaires, only 40% of staff understood where to stand whilst radiation was being used, and only 25% of staff knew where to find protective equipment. Conclusion: Overall our audit showed poor compliance with regards to the National and local policies, due to lack of awareness of the policy and lack of basic ionising radiation exposure knowledge. It was evident from the observational study and questionnaire that staff were not fully aware of what equipment should be worn, where to find such equipment and did not appreciate that the distance from the ionising radiation source altered its exposure effect. This lack of knowledge may affect the staff health and safety after long term exposure. Changes to clinical practice: From the outcome of this study, we managed to drastically increase awareness of ionising radiation within the orthopaedic department. A mandatory teaching session on the safety of ionising radiation has been incorporated into the orthopaedic induction week for all staff. The dosimeters have been moved to a visible location within the trauma operating theatre and all staff made aware of where to find protective equipment.

Keywords: audit, ionising radiation, observational study, protection

Procedia PDF Downloads 240

Authors: Ying-Chang Yu, Yuan-Lung Lo

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

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

Procedia PDF Downloads 197

Authors: Lamphong Volady

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The primary purpose of this study was to explore the traditional cuisine (local food) of Luangprabang Province in line with the Lao PDR’s One District One Product Policy. Another purpose of the study was to examine channels used to present local food, reasons to preserve and promote local food, as well as local food preservation and promotion strategies. It also aimed at testing correlation hypotheses whether there is a statistically significant relationship between enjoyment of having local food and willingness to promote local cuisines becoming international cuisines, attractiveness to consume local food, preservation and promotion of local food problems, and local people’s occupations. The Convergent Parallel Mixed Methods were employed in this study. The results of the study showed that several local cuisines were found to be local food of Luangprabang Province, namely Jeow Bon (Chilli dipping suace), Or Lam or aw lahm (stew buffalo skin, herbs, Mai sakaan), Kai Pan (River Weed Dry), Tam Mak Houng Luangprabang (Papaya Salad), Nang (Yam Buffalo Skin Dry), Sai Oor (Sausage), Laap Sin Koay Sai Mar-Keua Pao (Beef Salad with Roasted Eggplants), Orm Born (Taro leaves Stew), Oor Nor Mai (Bamboo Shoot Sausage), Jeow Nam Poo (Pickled Crab Chillies), Mok Dok Kae (steaming or roasting a Dok Kae Wrapp), Nor Sa Wan, Kao Noom Kee Noo, Kao Noom Ba Bin. It also depicted that YouTube, Facebook, and TikTok were multiple social channels or platforms which were found to be used to introduce traditional food as well as television, smartphone, word of mouth, Lao food fairs and other provincial events. The study also found that local food should be preserved and promoted since traditional food is not only ancestral, ancient, traditional, and local cuisines, but it is also wisdom, unique, and national cuisine. The study also found that people feel attracted to consuming local food because local food is delicious, unique, clean, nutritious, non-contaminated and natural. The study showed that lack of funds to produce local food, inadequate draw materials, lack material to store products, insufficient place to produce and lack of related organizations engagement were found to be problems for preserving and promoting traditional food. Finally, the result of the study revealed that there is a statistically significant weak relationship between enjoyment of having local food and willingness to promote local cuisines becoming international cuisines (R²= 4.5%), (p-value <0.001). There is a statistically significant moderate relationship between enjoyment of having local food and attractiveness to consume local food (R²= 7.8%), (p-value <0.001). However, there is a statistically insignificant relationship between enjoyment of having local food and preservation and promotion of local food problems (R²= 1.8%), (p-value = 0.086). It was found that there is a statistically insignificant relationship between enjoyment of having local food and local people’s occupations (R²= 0.0%), (p-value = 0.929).

Keywords: local food, preservation, promotion, traditional food, cuisines

Procedia PDF Downloads 52

Authors: A. T. Perez Fontenla, S. Sgobba, A. Bartkowska, Y. Askar, M. Dalemir Celuch, A. Newborough, M. Karppinen, H. Haalien, S. Deleval, S. Larcher, C. Charvet, L. Bruno, R. Trant

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The present study investigates the corrosion behavior of copper (Cu) based conducts predominantly brazed with Sil-Fos (self-fluxing copper-based filler with silver and phosphorus) within various cooling circuits of demineralized water across different particle accelerator components at CERN. The study covers a range of sample service time, from a few months to fifty years, and includes various accelerator components such as quadrupoles, dipoles, and bending magnets. The investigation comprises the established sample extraction procedure, examination methodology including non-destructive testing, evaluation of the corrosion phenomena, and identification of commonalities across the studied components as well as analysis of the environmental influence. The systematic analysis included computed microtomography (CT) of the joints that revealed distributed defects across all brazing interfaces. Some defects appeared to result from areas not wetted by the filler during the brazing operation, displaying round shapes, while others exhibited irregular contours and radial alignment, indicative of a network or interconnection. The subsequent dry cutting performed facilitated access to the conduct's inner surface and the brazed joints for further inspection through light and electron microscopy (SEM) and chemical analysis via Energy Dispersive X-ray spectroscopy (EDS). Brazing analysis away from affected areas identified the expected phases for a Sil-Fos alloy. In contrast, the affected locations displayed micrometric cavities propagating into the material, along with selective corrosion of the bulk Cu initiated at the conductor-braze interface. Corrosion product analysis highlighted the consistent presence of sulfur (up to 6 % in weight), whose origin and role in the corrosion initiation and extension is being further investigated. The importance of this study is paramount as it plays a crucial role in comprehending the underlying factors contributing to recently identified water leaks and evaluating the extent of the issue. Its primary objective is to provide essential insights for the repair of impacted brazed joints when accessibility permits. Moreover, the study seeks to contribute to the improvement of design and manufacturing practices for future components, ultimately enhancing the overall reliability and performance of magnet systems within CERN accelerator facilities.

Keywords: accelerator facilities, brazed copper conducts, demineralized water, magnets

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Authors: Stanislavs Gendelis, Maris Sinka, Andris Jakovics

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Insulation materials made from natural sources have become more popular for the ecologisation of buildings, meaning wide use of such renewable materials. Such natural materials replace synthetic products which consume a large quantity of energy. The most common and the cheapest natural materials in Latvia are cellulose-based (wood and agricultural plants). The ecological aspects of such materials are well known, but experimental data about physical properties remains lacking. In this study, six different samples of wood wool panels and a mixture of hemp shives and lime (hempcrete) are analysed. Thermal conductivity and heat capacity measurements were carried out for wood wool and cement panels using the calibrated hot plate device. Water vapor permeability was tested for hempcrete material by using the gravimetric dry cup method. Studied wood wool panels are eco-friendly and harmless material, which is widely used in the interior design of public and residential buildings, where noise absorption and sound insulation is of importance. They are also suitable for high humidity facilities (e.g., swimming pools). The difference in panels was the width of used wood wool, which is linked to their density. The results of measured thermal conductivity are in a wide range, showing the worsening of properties with the increasing of the wool width (for the least dense 0.066, for the densest 0.091 W/(m·K)). Comparison with mineral insulation materials shows that thermal conductivity for such materials are 2-3 times higher and are comparable to plywood and fibreboard. Measured heat capacity was in a narrower range; here, the dependence on the wool width was not so strong due to the fact that heat capacity value is related to mass, not volume. The resulting heat capacity is a combination of two main components. A comparison of results for different panels allows to select the most suitable sample for a specific application because the dependencies of the thermal insulation and heat capacity properties on the wool width are not the same. Hempcrete is a much denser material compared to conventional thermal insulating materials. Therefore, its use helps to reinforce the structural capacity of the constructional framework, at the same time, it is lightweight. By altering the proportions of the ingredients, hempcrete can be produced as a structural, thermal, or moisture absorbent component. The water absorption and water vapor permeability are the most important properties of these materials. Information about absorption can be found in the literature, but there are no data about water vapor transmission properties. Water vapor permeability was tested for a sample of locally made hempcrete using different air humidity values to evaluate the possible difference. The results show only the slight influence of the air humidity on the water vapor permeability value. The absolute ‘sd value’ measured is similar to mineral wool and wood fiberboard, meaning that due to very low resistance, water vapor passes easily through the material. At the same time, other properties – structural and thermal of the hempcrete is totally different. As a result, an experimentally-based knowledge of thermal and water vapor transmission properties for cellulose-based materials was significantly improved.

Keywords: heat capacity, hemp concrete, thermal conductivity, water vapor transmission, wood wool

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Authors: Rick Evans

Abstract:

Despite over 40 years of research into why women choose not to enroll or leave undergraduate engineering programs, along with the subsequent and serious efforts to attract more women, women receiving bachelor's degrees in engineering in the US have remained disappointingly low. We know that even despite their struggles to become more welcoming and inclusive, engineering programs remain gendered, raced and classed. However, our research team has found that women who participate and indeed thrive in undergraduate engineering project teams do so in numbers that far exceed their participation in undergraduate programs. We believe part of the answer lies in the ways that project teams facilitate experiential learning, specifically providing opportunities for members to play, practice and perform. We employ a multi-case study method and assume a feminist, activist and interpretive perspective. We seek to generate concrete and context-dependent knowledge in order to explore potentially new variables and hypotheses. Our focus is to learn from those select women who are thriving. For this oral or e-poster presentation, we will focus on the results of the second of our semi-structured interviews – the learning journey interview. During this interview, we ask participants to tell us the story/ies of their participation in project teams. Our results suggest these women find joy in their experience of developing and applying engineering expertise. They experience this joy and develop their expertise in the highly patterned progression of play, practice and performance. Play is a purposeful activity in which someone enters an imaginary world, a world not yet real to them. However, this imaginary world is still very much connected to the real world, in this case, a particular kind of engineering, in that the ways of engaging are already established, codified and rule-governed. As such, these women are novices motivated to join a community of actors. Practice, better understood as practices, a count noun, is an embodied, materially interconnected collection of actions organized around the shared understandings of that community of actors. Those shared understandings reveal a social order – a particular field of engineering. No longer novices, these women begin to develop and display their emergent identities as engineers. Perform is activity meant either to demonstrate competence and/or to enable, even teach play and practice to others. As performers, these women participants become models for others. They direct play and practice, contextualizing both within a field of engineering and the specific aims of the project team community. By playing, practicing and performing engineering, women claim their identities as engineers and, equally important, have those identities acknowledged by team members. If we hope to transform our gendered, raced, classed institutions, we need to learn more about women who thrive within those institutions. We need to learn more about their processes of becoming and belonging as engineers. Our research presentation begins with a description of project teams and our multi-case study method. We then offer detailed descriptions of play, practice, and performance using the voices of women in project teams.

Keywords: engineering education, gender, identity, project teams

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Authors: Abdulmajeed Abdullah Alqarni

Abstract:

This paper is devoted a study of the current frameworks applicable to foreign investments at the levels of domestic and international law, with a particular focus on the legitimate balance to be achieved between the rights of the host state and the legal protections owed to foreign investors. At the wider level of analysis, the paper attempts to map and critically examine the relationship between foreign investment and economic development. In doing so, the paper offers a study in how current discourses and practices on investment law can reconcile the competing interests of developing and developed countries. The study draws on the growing economic imperative for developing nations to create a favorable investment climate capable of attracting private foreign investment. It notes that that over the past decades, an abundance of legal standards that establish substantive and procedural protections for legal forms of foreign investments in the host countries have evolved and crystalized. The study then goes on to offer a substantive analysis of legal reforms at the domestic level in countries such as Saudi Arabia before going on to provide an in- depth and substantive examination of the most important instruments developed at the levels of international law: bilateral investment agreements and double taxation agreements. As to its methods, the study draws on case studies and from data assessing the link between double taxation and economic development. Drawing from the extant literature and doctrinal research, and international and comparative jurisprudence, the paper excavates and critically examines contemporary definitions and norms of international investment law, many of which have been given concrete form and specificity in an ever-expanding number of bilateral and multilateral investment treaties. By reconsidering the wider challenges of conflicts of law and jurisdiction, and the competing aims of the modern investment law regime, the study reflects on how bilateral investment treaties might succeed in achieving the dual aims of rights protection and economic sovereignty. Through its examination of the double taxation phenomena, the study goes on to identify key practical challenges raised by the implementation of bilateral treaties whilst also assessing the sufficiency of the domestic and international legal solutions that are proposed in response. In its final analysis, the study aims to contribute to existing scholarship by assessing contemporary legal and economic barriers to the free flow of investment with due regard for the legitimate concerns and diversity of developing nations. It does by situating its analysis of the domestic enforcement of international investment instrument in its wider historical and normative context. By focusing on the economic and legal dimensions of foreign investment, the paper also aims to offer an interdisciplinary and holistic perspective on contemporary issues and developments in investment law while offering practical reform proposals that can be used to be achieve a more equitable balance between the rights and interests of states and private entities in an increasingly trans nationalized sphere of investment regulation and treaty arbitration.

Keywords: foreign investment, bilateral investment treaties, international tax law, double taxation treaties

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Authors: Qiang Guo, Ruying Qi

Abstract:

This project aims to trace the developmental patterns of a child's Mandarin and English from China to Australia from age 3; 03 till 5; 06. In childhood bilingual studies, there is an assumption that age 3 is the dividing line between simultaneous bilinguals and sequential bilinguals. Determining similarities and differences between Bilingual First Language Acquisition, Early Second Language Acquisition, and Second Language Acquisition is of great theoretical significance. Studies on Bilingual First Language Acquisition, hereafter, BFLA in the past three decades have shown that the grammatical development of bilingual children progresses through the same developmental trajectories as their monolingual counterparts. Cross-linguistic interaction does not show changes of the basic grammatical knowledge, even in the weaker language. While BFLA studies show consistent results under the conditions of adequate input and meaningful interactional context, the research findings of Early Second Language Acquisition (ESLA) have demonstrated that this cohort proceeds their early English differently from both BFLA and SLA. The different development could be attributed to the age of migration, input pattern, and their Environmental Languages (Lε). In the meantime, the dynamic relationship between the two languages is an issue to invite further attention. The present study attempts to fill this gap. The child in this case study started acquiring L1 Mandarin from birth in China, where the environmental language (Lε) coincided with L1 Mandarin. When she migrated to Australia at 3;06, where the environmental language (Lε) was L2 English, her Mandarin exposure was reduced. On the other hand, she received limited English input starting from 1; 02 in China, where the environmental language (Lε) was L1 Mandarin, a non-English environment. When she relocated to Australia at 3; 06, where the environmental language (Lε) coincided with L2 English, her English exposure significantly increased. The child’s linguistic profile provides an opportunity to explore: (1) What does the child’s English developmental route look like? (2) What does the L1 Mandarin developmental pattern look like in different environmental languages? (3) How do input and environmental language interact in shaping the bilingual child’s linguistic repertoire? In order to answer these questions, two linguistic areas are selected as the focus of the investigation, namely, subject realization and wh-questions. The chosen areas are contrastive in structure but perform the same semantic functions in the two linguistically distant languages and can serve as an ideal testing ground for exploring the developmental path in the two languages. The longitudinal case study adopts a combined approach of qualitative and quantitative analysis. Two years’ Mandarin and English data are examined, and comparisons are made with age-matched monolinguals in each language in CHILDES. To the author’s best knowledge, this study is the first of this kind examining a Mandarin-English bilingual child's bilingual development at a critical age, in different input patterns, and in different environmental languages (Lε). It also expands the scope of the theory of Lε, adding empirical evidence on the relationship between input and Lε in bilingual acquisition.

Keywords: bilingual development, age, input, environmental language (Le)

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Authors: Šárka Hradilová, Aleš Panáček, Radek Zbořil

Abstract:

Nanotechnologies are considered the most promising fields with high added value, brings new possibilities in various sectors from industry to medicine. With the growing of interest in nanomaterials and their applications, increasing nanoparticle production leads to increased exposure of people and environment with ‘human made’ nanoparticles. Nanoparticles (NPs) are clusters of atoms in the size range of 1–100 nm. Metal nanoparticles represent one of the most important and frequently used types of NPs due to their unique physical, chemical and biological properties, which significantly differ from those of bulk material. Biological properties including toxicity of metal nanoparticles are generally determined by their size, size distribution, shape, surface area, surface charge, surface chemistry, stability in the environment and ability to release metal ions. Therefore, the biological behavior of NPs and their possible adverse effect cannot be derived from the bulk form of material because nanoparticles show unique properties and interactions with biological systems just due to their nanodimensions. Silver and gold NPs are intensively studied and used. Both can be used for instance in surface enhanced Raman spectroscopy, a considerable number of applications of silver NPs is associated with antibacterial effects, while gold NPs are associated with cancer treatment and bio imaging. Antibacterial effects of silver ions are known for centuries. Silver ions and silver-based compounds are highly toxic to microorganisms. Toxic properties of silver NPs are intensively studied, but the mechanism of cytoxicity is not fully understood. While silver NPs are considered toxic, gold NPs are referred to as toxic but also innocuous for eukaryotic cells. Therefore, gold NPs are used in various biological applications without a risk of cell damaging, even when we want to suppress the growth of cancer cells. Thus, gold NPs are toxic or harmless. Because most studies comparing particles of various sizes prepared in various ways, and testing is performed on different cell lines, it is very difficult to generalize. The novelty and significance of our research is focused to the complex biological effects of silver and gold NPs prepared by the same method, have the same parameters and the same stabilizer. That is why we can compare the biological effects of pure nanometals themselves based on their chemical nature without the influence of other variable. Aim of our study therefore is to compare the cytotoxic effect of two types of noble metal NPs focusing on the mechanisms that contribute to cytotoxicity. The study was conducted on murine fibroblasts by selected common used tests. Each of these tests monitors the selected area related to toxicity and together provides a comprehensive view on the issue of interactions of nanoparticles and living cells.

Keywords: cytotoxicity, gold nanoparticles, mechanism of cytotoxicity, silver nanoparticles

Procedia PDF Downloads 229