Search results for: free and projective modules

Authors: Faisal Anwar, Dawar Zaidi, Shubham Dixit, Nafees Ahmedii

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This paper analyzes the various properties of biodiesel such as pour point, cloud point, viscosity, calorific value, etc produced from different feedstocks. The aim of the work is to analyze change in these properties after converting feedstocks to biodiesel and then comparring it with ASTM 6751-02 standards to check whether they are suitable for diesel engines or not. The conversion of feedstocks is carried out by a process called transesterification. This conversion is carried out to reduce viscosity, pour point, etc. It has been observed that there is some remarkable change in the properties of oil after conversion.

Keywords: biodiesel, ethyl ester, free fatty acid, production

Procedia PDF Downloads 367

Authors: Ruolan Zhang, Ryo Imai, Naoko Senda, Tomoyuki Sakai

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Enzymes have attracted increasing attentions in industrial manufacturing for their applicability in catalyzing complex chemical reactions under mild conditions. Directed evolution has become a powerful approach to optimize enzymes and exploit their full potentials under the circumstance of insufficient structure-function knowledge. With the incorporation of cell-free synthetic biotechnology, rapid enzyme synthesis can be realized because no cloning procedure such as transfection is needed. Its open environment also enables direct enzyme measurement. These properties of cell-free biotechnology lead to excellent throughput of enzymes generation. However, the capabilities of current screening methods have limitations. Fluorescence-based assay needs applicable fluorescent label, and the reliability of acquired enzymatic activity is influenced by fluorescent label’s binding affinity and photostability. To acquire the natural activity of an enzyme, another method is to combine pre-screening step and high-performance liquid chromatography (HPLC) measurement. But its throughput is limited by necessary time investment. Hundreds of variants are selected from libraries, and their enzymatic activities are then identified one by one by HPLC. The turn-around-time is 30 minutes for one sample by HPLC, which limits the acquirable enzyme improvement within reasonable time. To achieve the real high-throughput enzyme screening, i.e., obtain reliable enzyme improvement within reasonable time, a widely applicable high-throughput measurement of enzymatic reactions is highly demanded. Here, a high-throughput screening method using broadband coherent anti-Stokes Raman spectroscopy (CARS) was proposed. CARS is one of coherent Raman spectroscopy, which can identify label-free chemical components specifically from their inherent molecular vibration. These characteristic vibrational signals are generated from different vibrational modes of chemical bonds. With the broadband CARS, chemicals in one sample can be identified from their signals in one broadband CARS spectrum. Moreover, it can magnify the signal levels to several orders of magnitude greater than spontaneous Raman systems, and therefore has the potential to evaluate chemical's concentration rapidly. As a demonstration of screening with CARS, alcohol dehydrogenase, which converts ethanol and nicotinamide adenine dinucleotide oxidized form (NAD+) to acetaldehyde and nicotinamide adenine dinucleotide reduced form (NADH), was used. The signal of NADH at 1660 cm⁻¹, which is generated from nicotinamide in NADH, was utilized to measure the concentration of it. The evaluation time for CARS signal of NADH was determined to be as short as 0.33 seconds while having a system sensitivity of 2.5 mM. The time course of alcohol dehydrogenase reaction was successfully measured from increasing signal intensity of NADH. This measurement result of CARS was consistent with the result of a conventional method, UV-Vis. CARS is expected to have application in high-throughput enzyme screening and realize more reliable enzyme improvement within reasonable time.

Keywords: Coherent Anti-Stokes Raman Spectroscopy, CARS, directed evolution, enzyme screening, Raman spectroscopy

Procedia PDF Downloads 141

Authors: Meltem Betül Sağlam, Halil İbrahim Güler, Aykut Sağlam

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In this work, phthalocyanine compounds containing α-naphtholbenzeinunits have been synthesized. Mutagenicity and DNA binding properties of the compounds were investigated by Salmonella/Microsome Assay and spectrophotometer. According to the results of the preliminary range finding tests, the compounds gave no toxic effect to all tester strain S. typhimurium TA98 and TA100 at doses of 500, 1100, 350, 500 and 750 µg/plate in the presence and absence of S9, respectively. This study showed that all compounds exhibited efficient DNA-binding activity. In conclusion, these non-toxic compounds may be used as effective DNA dyes for molecular biology studies.

Keywords: dye, mutagenicity, phthalocyanine, toxicity

Procedia PDF Downloads 231

Authors: Dulani Jayasuriya

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This study outlines the developmental steps of a chatbot for administrative purposes of a large undergraduate course. The chatbot is able to handle student queries about administrative details, including assessment deadlines, course documentation, how to navigate the course, group formation, etc. The development window screenshots are that of a free account on the Snatchbot platform such that this can be adopted by the wider public. While only one connection to an answer based on possible keywords is shown here, one needs to develop multiple connections leading to different answers based on different keywords for the actual chatbot to function. The overall flow of the chatbot showing connections between different interactions is depicted at the end.

Keywords: chatbots, education, technology, snatch bot, artificial intelligence

Procedia PDF Downloads 104

Authors: Bartlomiej Przybyszewski, Rafal Kozera, Katarzyna Zolynska, Anna Boczkowska, Daria Pakula

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The build-up and accumulation of dirt, ice, and snow on structural elements and vehicles is an unfavorable phenomenon, leading to economic losses and often also posing a threat to people. This problem occurs wherever the use of polymer coatings has become a standard, among others in photovoltaic farms, aviation, wind energy, and civil engineering. The accumulated pollution on the photovoltaic modules can reduce their efficiency by several percent, and snow stops power production. Accumulated ice on the blades of wind turbines or the wings of airplanes and drones disrupts the airflow by changing their shape, leading to increased drag and reduced efficiency. This results in costly maintenance and repairs. The goal of the work is to reduce or completely eliminate the accumulation of dirt, snow, and ice build-up on polymer coatings by achieving self-cleaning and icephobic properties. It is done by the use of a multi-step surface modification of the polymer nanocoatings. For this purpose, two methods of surface structuring and the preceding volumetric modification of the chemical composition with proprietary organosilicon compounds and/or mineral additives were used. To characterize the surface topography of the modified coatings, light profilometry was utilized. Measurements of the wettability parameters (static contact angle and contact angle hysteresis) on the investigated surfaces allowed to identify their wetting behavior and determine relation between hydrophobic and anti-icing properties. Ice adhesion strength was measured to assess coatings' anti-icing behavior.

Keywords: anti-icing properties, self-cleaning, polymer coatings, icephobic coatings

Procedia PDF Downloads 108

Authors: Athira Vinod

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Under the Right to Education Act (2009), the Indian government introduced an affirmative action policy aimed at the reservation of seats in private schools at the entry-level and free primary education for children from lower socio-economic backgrounds. Using exogenous variation in the status of being in a lower social category (disadvantaged groups) and the year of starting school, this study investigates the effect of exposure to the policy on the expenditure on private education. It employs a difference-in-difference strategy with the help of repeated cross-sectional household data from the National Sample Survey (NSS) of India. It also exploits regional variation in exposure by combining the household data with administrative data on schools from the District Information System for Education (DISE). The study compares the outcome across two age cohorts of disadvantaged groups, starting school at different times, that is, before and after the policy. Regional variation in exposure is proxied with a measure of enrolment rate under the policy, calculated at the district level. The study finds that exposure to the policy led to an average reduction in annual private school fees of ₹223. Similarly, a 5% increase in the rate of enrolment under the policy in a district was associated with a reduction in annual private school fees of ₹240. Furthermore, there was a larger effect of the policy among households with a higher demand for private education. However, the effect is not due to fees waived through direct enrolment under the policy but rather an increase in the supply of low-fee private schools in India. The study finds that after the policy, 79,870 more private schools entered the market due to an increased demand for private education. The new schools, on average, charged a lower fee than existing schools and had a higher enrolment of children exposed to the policy. Additionally, the district-level variation in the enrolment under the policy was very strongly correlated with the entry of new schools, which not only charged a low fee but also had a higher enrolment under the policy. Results suggest that few disadvantaged children were admitted directly under the policy, but many were attending private schools, which were largely low-fee. This implies that disadvantaged households were willing to pay a lower fee to secure a place in a private school even if they did not receive a free place under the policy.

Keywords: affirmative action, disadvantaged groups, private schools, right to education act, school fees

Procedia PDF Downloads 116

Authors: Iliya Dimitrov Stoev, Benjamin Seelbinder, Elena Erben, Nicola Maghelli, Moritz Kreysing

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Despite the revolutionizing impact of optical tweezers in materials science and cell biology up to the present date, trapping has so far extensively relied on specific material properties of the probe and local heating has limited applications related to investigating dynamic processes within living systems. To overcome these limitations while maintaining high sensitivity, here we present a new optofluidic approach that can be used to gently trap microscopic particles and measure femtoNewton forces in a contact-free manner and with thermally limited precision.

Keywords: optofluidics, force measurements, microrheology, FLUCS, thermoviscous flows

Procedia PDF Downloads 170

Authors: C. W. Kan

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Cotton is the most commonly used material for apparel purpose because of its durability, good perspiration absorption characteristics, comfort during wear and dyeability. However, proneness to creasing and wrinkling give cotton garments a poor rating during actual wear. Resin finishing is a process to bring out crease or wrinkle free/resistant effect to cotton fabric. Thus, the aim of this study is to illustrate the proper application of resin finishing to cotton fabric, and the results could provide guidance note to the students in learning this topic. Acknowledgment: Authors would like to thank the financial support from the Hong Kong Polytechnic University for this work.

Keywords: learning materials, resin, textiles, wrinkle

Procedia PDF Downloads 254

Authors: W. Shin, Y. Kim

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This study focuses on disconfirming that wide-area networks can be made mobile, highly-available, and wireless. This methodological test shows that IPv7 and context-free grammar are mismatched. In the cases of robots, a similar tendency is also revealed. Further, we also prove that public-private key pairs could be built embedded, adaptive, and wireless. Finally, we disconfirm that although hash tables can be made distributed, interposable, and autonomous, XML and DNS can interfere to realize this purpose. Our experiments soon proved that exokernelizing our replicated Knesis keyboards was more significant than interrupting them. Our experiments exhibited degraded average sampling rate.

Keywords: collaborative communication, DNS, local-area networks, XML

Procedia PDF Downloads 187

Authors: Reni Francis

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Learning has transcended the classroom boundaries to create a learner centric, interactive, and integrative teaching learning environment. This study analysed the impact of iLearn on the teaching, learning, and evaluation among 100 teacher trainees. The objectives were to cater to the different learning styles of the teacher trainees, to incorporate innovative teaching learning activities, to assist in peer tutoring, to implement different evaluation processes. i: Identifying the learning styles among the teacher trainees through VARK Learning style checklist was followed by planning the teaching-learning process to meet the learning styles of the teacher trainees. L: Leveraging innovations in teaching- learning by planning and creating modules incorporating innovative teaching learning and hence the concept based year plan was prepared. E: Engage learning through constructivism using different teaching methodology to engage the teacher trainees in the learning process through Workshop, Round Robin, Gallery walk, Co-Operative learning, Think-Pair-Share, EDMODO, Course Networking, Concept Map, Brainstorming Sessions, Video Clippings. A: Assessing the learning through an Open Book assignment, Closed book assignment, and Multiple Choice Questions and Seminar presentation. R: Remediation through peer tutoring through Mentor-mentee approach in the tutorial groups, Group work, Library Hours. N: Norming new standards. This was done in the form of extended remediation and tutorials to understand the need of the teacher trainee and support them for further achievements in learning through Face to face interaction, Supervised Study Circle, Mobile (Device) learning. The findings of the study revealed the positive impact of iLearn towards student achievement and enhanced social skills.

Keywords: academic achievement, innovative strategy, learning styles, social skills

Procedia PDF Downloads 356

Authors: Nimet Yildirim Tirgil, Ahmed Busnaina, April Z. Gu

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Environmental waters are monitored worldwide to protect people from infectious diseases primarily caused by enteric pathogens. All long, Escherichia coli (E. coli) is a good indicator for potential enteric pathogens in waters. Thus, a rapid and simple detection method for E. coli is very important to predict the pathogen contamination. In this study, to the best of our knowledge, as the first time we developed a rapid, direct and reusable SWCNTs (single walled carbon nanotubes) based biosensor system for sensitive and selective E. coli detection in water samples. We use a novel and newly developed flexible biosensor device which was fabricated by high-rate nanoscale offset printing process using directed assembly and transfer of SWCNTs. By simple directed assembly and non-covalent functionalization, aptamer (biorecognition element that specifically distinguish the E. coli O157:H7 strain from other pathogens) based SWCNTs biosensor system was designed and was further evaluated for environmental applications with simple and cost-effective steps. The two gold electrode terminals and SWCNTs-bridge between them allow continuous resistance response monitoring for the E. coli detection. The detection procedure is based on competitive mode detection. A known concentration of aptamer and E. coli cells were mixed and after a certain time filtered. The rest of free aptamers injected to the system. With hybridization of the free aptamers and their SWCNTs surface immobilized probe DNA (complementary-DNA for E. coli aptamer), we can monitor the resistance difference which is proportional to the amount of the E. coli. Thus, we can detect the E. coli without injecting it directly onto the sensing surface, and we could protect the electrode surface from the aggregation of target bacteria or other pollutants that may come from real wastewater samples. After optimization experiments, the linear detection range was determined from 2 cfu/ml to 10⁵ cfu/ml with higher than 0.98 R² value. The system was regenerated successfully with 5 % SDS solution over 100 times without any significant deterioration of the sensor performance. The developed system had high specificity towards E. coli (less than 20 % signal with other pathogens), and it could be applied to real water samples with 86 to 101 % recovery and 3 to 18 % cv values (n=3).

Keywords: aptamer, E. coli, environmental detection, nanobiosensor, SWCTs

Procedia PDF Downloads 197

Authors: Fumin Wang, Jiaqi Yin, Lajun Wang, Nan Chi

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In this article, we demonstrate a visible light communication (VLC) system over 8 meters free space transmission based on a commercial LED and a receiver in connection with an audio interface of a smart phone. The signal is in FSK modulation format. The successful experimental demonstration validates the feasibility of the proposed system in future wireless communication network.

Keywords: visible light communication, smartphone communication, frequency shift keying, wireless communication

Procedia PDF Downloads 391

Authors: Z. Abram, V. Nadasan, J. Balint, J. L. Ferencz

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Introduction: Online smoking prevention programs became popular in the last time. In order to extend the use of such programs, existing applications can be adapted and translated in the native languages of the target groups. It is the first time that in Romania such a software was implemented. Our goal was to provide a computer-aided intervention with attractive content targeting high school students who are familiar with information and communication technology. Material and methods: ASPIRA is the Romanian/Hungarian adapted version of a smoking prevention program created in USA. Prior to apply the questionnaire and ASPIRA online program which contains five modules that include tests, videos and interactive games, the program was tested in some IT laboratories on a group of schoolchildren and students. The pilot study questionnaires were completed considering the opinions of young people and the functionality of the software. Results: Above 90% of participants reported a good or very good impression about the ASPIRA program. Only a small minority found that the program included some parts which were too long or reported the existence of any technical problems regarding the functionality of the software. 76% of the participants had little or very little difficulty in understanding the messages presented by the English speaking characters. Only 7.5% of the participants thought that the program included content that was not appropriate for the local culture. Conclusions: The vast majority of students reported favorite impressions about ASPIRA online program. High school students and boys were more critical. Language and cultural barriers did not have the potential to reduce in a significant manner the effectiveness of the tested program.

Keywords: smoking prevention, ASPIRA online program, youth opinions, language/cultural barriers

Procedia PDF Downloads 260

Authors: Rachmat Mauludin, Dita Sasri Primaviri, Irda Fidrianny

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Propolis contains several antioxidant compounds which can be used in topical application to protect skin against free radical, prevent skin cancer and skin aging. Previous study showed that 70% ethanolic extract of propolis (EEP) provided the greatest antioxidant activity. Since EEP has very small solubility in water, the extract was prepared in nanoemulsion (NE). Nanoemulsion is chosen as cosmetic dosage forms according to its properties namely to decrease the risk of skin’s irritation, increase penetration, prolong its time to remain in our skin, and improve stability. Propolis was extracted using reflux methods and concentrated using rotavapor. EEP was characterized with several tests such as phytochemical screening, density, and antioxidant activity using DPPH method. Optimation of total surfactant, co-surfactant, oil, and amount of EEP that can be included in NE were required to get the best NE formulation. The evaluations included to organoleptic observation, globul size, polydispersity index, morphology using TEM, viscosity, pH, centrifuge, stability, Freeze and Thaw test, radical scavenging activity using DPPH method, and primary irritation test. The yield extracts was 11.12% from raw propolis contained of steroid/triterpenoid, flavonoid, and saponin based on phytochemical screening. EEP had the value of DPPH scavenging activity 61.14% and IC50 0.41629 ppm. The best NE formulation consisted of 26.25% Kolliphor RH40; 8.75% glycerine; 5% rice bran oil; and 3% EEP. NE was transparant, had globul size of 21.9 nm; polydispersity index of 0.338; and pH of 5.67. Based on TEM morphology, NE was almost spherical and has particle size below 50 nm. NE propolis revealed to be physically stable after stability test within 63 days at 25oC, centrifuged for 30 mins at 13.000 rpm, and passed 6 cycles of Freeze and Thaw test without separated. NE propolis reduced 58% of free radical DPPH similar to antioxidant activity of the original extracts. Antioxidant activity of NE propolis is relatively stable after stored for 6 weeks. NE Propolis was proven to be safe by primary irritation test with the value of primary irritation index (OECD) was 0. The best formulation for NE propolis contained of 26.25% Kolliphor RH40; 8.75% glycerine; 5% rice bran oil; and 3% EEP with globul size of 21.9 nm and polydispersity index of 0.338. NE propolis was stable and had antioxidant activity similar to EEP.

Keywords: propolis, antioxidant, nanoemulsion, irritation test

Procedia PDF Downloads 305

Authors: Alexander Rych

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Piql Preservation Services (“Piql”) is a turnkey solution designed for secure, migration-free long- term preservation of digital data. Piql sets an open standard for long- term preservation for the future. It consists of equipment and processes needed for writing and retrieving digital data. Exponentially growing amounts of data demand for logistically effective and cost effective processes. Digital storage media (hard disks, magnetic tape) exhibit limited lifetime. Repetitive data migration to overcome rapid obsolescence of hardware and software bears accelerated risk of data loss, data corruption or even manipulation and adds significant repetitive costs for hardware and software investments. Piql stores any kind of data in its digital as well as analog form securely for 500 years. The medium that provides this is a film reel. Using photosensitive film polyester base, a very stable material that is known for its immutability over hundreds of years, secure and cost-effective long- term preservation can be provided. The film reel itself is stored in a packaging capable of protecting the optical storage medium. These components have undergone extensive testing to ensure longevity of up to 500 years. In addition to its durability, film is a true WORM (write once- read many) medium. It therefore is resistant to editing or manipulation. Being able to store any form of data onto the film makes Piql a superior solution for long-term preservation. Paper documents, images, video or audio sequences – all of those file formats and documents can be preserved in its native file structure. In order to restore the encoded digital data, only a film scanner, a digital camera or any appropriate optical reading device will be needed in the future. Every film reel includes an index section describing the data saved on the film. It also contains a content section carrying meta-data, enabling users in the future to rebuild software in order to read and decode the digital information.

Keywords: digital data, long-term preservation, migration-free, photosensitive film

Procedia PDF Downloads 392

Authors: Chia-Chi Chang, Chuan-Bi Lin, Chia-Min Chan

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Most ZigBee sensor networks to date make use of nodes with limited processing, communication, and energy capabilities. Energy consumption is of great importance in wireless sensor applications as their nodes are commonly battery-driven. Once ZigBee nodes are deployed outdoors, limited power may make a sensor network useless before its purpose is complete. At present, there are two strategies for long node and network lifetime. The first strategy is saving energy as much as possible. The energy consumption will be minimized through switching the node from active mode to sleep mode and routing protocol with ultra-low energy consumption. The second strategy is to evaluate the energy consumption of sensor applications as accurately as possible. Erroneous energy model may render a ZigBee sensor network useless before changing batteries. In this paper, we present a ZigBee wireless sensor node with four key modules: a processing and radio unit, an energy harvesting unit, an energy storage unit, and a sensor unit. The processing unit uses CC2530 for controlling the sensor, carrying out routing protocol, and performing wireless communication with other nodes. The harvesting unit uses a 2W solar panel to provide lasting energy for the node. The storage unit consists of a rechargeable 1200 mAh Li-ion battery and a battery charger using a constant-current/constant-voltage algorithm. Our solution to extend node lifetime is implemented. Finally, a long-term sensor network test is used to exhibit the functionality of the solar powered system.

Keywords: ZigBee, Li-ion battery, solar panel, CC2530

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Authors: Malik Sajjad Mehmood, Aisha Ali, Hamna Khan, Tariq Yasin, Masroor Ikram

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Ultra-high molecular weight polyethylene (UHMWPE) is one of the polymers belongs to polyethylene (PE) family having monomer –CH2– and average molecular weight is approximately 3-6 million g/mol. Due its chemical, mechanical, physical and biocompatible properties, it has been extensively used in the field of electrical insulation, medicine, orthopedic, microelectronics, engineering, chemistry and the food industry etc. In order to alter/modify the properties of UHMWPE for particular application of interest, certain various procedures are in practice e.g. treating the material with high energy irradiations like gamma ray, e-beam, and ion bombardment. Radiation treatment of UHMWPE induces free radicals within its matrix, and these free radicals are the precursors of chain scission, chain accumulation, formation of double bonds, molecular emission, crosslinking etc. All the aforementioned physical and chemical processes are mainly responsible for the modification of polymers properties to use them in any particular application of our interest e.g. to fabricate LEDs, optical sensors, antireflective coatings, polymeric optical fibers, and most importantly for radiation dosimetry applications. It is therefore, to check the feasibility of using UHMWPE for radiation dosimetery applications, the compressed sheets of UHMWPE were irradiated at room temperature (~25°C) for total dose values of 30 kGy and 100 kGy, respectively while one were kept un-irradiated as reference. Transmittance data (from 400 nm to 800 nm) of e-beam irradiated UHMWPE and its hybrids were measured by using Muller matrix spectro-polarimeter. As a result significant changes occur in the absorption behavior of irradiated samples. To analyze these (radiation induced) changes in polymer matrix Urbach edge method and modified Tauc’s equation has been used. The results reveal that optical activation energy decreases with irradiation. The values of activation energies are 2.85 meV, 2.48 meV, and 2.40 meV for control, 30 kGy, and 100 kGy samples, respectively. Direct and indirect energy band gaps were also found to decrease with irradiation due to variation of C=C unsaturation in clusters. We believe that the reported results would open new horizons for radiation dosimetery applications.

Keywords: electron beam, radiation dosimetry, Tauc’s equation, UHMWPE, Urbach method

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Authors: Dario Milani, Guido Morgenthal

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Fluid dynamic computation of wind caused forces on bluff bodies e.g light flexible civil structures or high incidence of ground approaching airplane wings, is one of the major criteria governing their design. For such structures a significant dynamic response may result, requiring the usage of small scale devices as guide-vanes in bridge design to control these effects. The focus of this paper is on the numerical simulation of the bluff body problem involving multiscale phenomena induced by small scale devices. One of the solution methods for the CFD simulation that is relatively successful in this class of applications is the Vortex Particle Method (VPM). The method is based on a grid free Lagrangian formulation of the Navier-Stokes equations, where the velocity field is modeled by particles representing local vorticity. These vortices are being convected due to the free stream velocity as well as diffused. This representation yields the main advantages of low numerical diffusion, compact discretization as the vorticity is strongly localized, implicitly accounting for the free-space boundary conditions typical for this class of FSI problems, and a natural representation of the vortex creation process inherent in bluff body flows. When the particle resolution reaches the Kolmogorov dissipation length, the method becomes a Direct Numerical Simulation (DNS). However, it is crucial to note that any solution method aims at balancing the computational cost against the accuracy achievable. In the classical VPM method, if the fluid domain is discretized by Np particles, the computational cost is O(Np2). For the coupled FSI problem of interest, for example large structures such as long-span bridges, the aerodynamic behavior may be influenced or even dominated by small structural details such as barriers, handrails or fairings. For such geometrically complex and dimensionally large structures, resolving the complete domain with the conventional VPM particle discretization might become prohibitively expensive to compute even for moderate numbers of particles. It is possible to reduce this cost either by reducing the number of particles or by controlling its local distribution. It is also possible to increase the accuracy of the solution without increasing substantially the global computational cost by computing a correction of the particle-particle interaction in some regions of interest. In this paper different strategies are presented in order to extend the conventional VPM method to reduce the computational cost whilst resolving the required details of the flow. The methods include temporal sub stepping to increase the accuracy of the particles convection in certain regions as well as dynamically re-discretizing the particle map to locally control the global and the local amount of particles. Finally, these methods will be applied on a test case and the improvements in the efficiency as well as the accuracy of the proposed extension to the method are presented. The important benefits in terms of accuracy and computational cost of the combination of these methods will be thus presented as long as their relevant applications.

Keywords: adaptation, fluid dynamic, remeshing, substepping, vortex particle method

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Authors: Tobias Schmithuesen, Johannes Henrich Schleifenbaum

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The additive manufacturing process laser powder bed fusion offers many advantages over conventional manufacturing processes. For example, almost any complex part can be produced, such as topologically optimized lightweight parts, which would be inconceivable with conventional manufacturing processes. A major challenge posed by the LPBF process, however, is, in most cases, the need to use and remove support structures on critically inclined part surfaces (α < 45 ° regarding substrate plate). These are mainly used for dimensionally accurate mapping of part contours and to reduce distortion by absorbing process-related internal stresses. Furthermore, they serve to transfer the process heat to the substrate plate and are, therefore, indispensable for the LPBF process. A major challenge for the economical use of the LPBF process in industrial process chains is currently still the high manual effort involved in removing support structures. According to the state of the art (SoA), the parts are usually treated by simple hand tools (e.g., pliers, chisels) or by machining (e.g., milling, turning). New automatable approaches are the removal of support structures by means of wet chemical ablation and thermal deburring. According to the state of the art, the support structures are essentially adapted to the LPBF process and not to potential post-processing steps. The aim of this study is the determination of support structure designs that are adapted to the mentioned post-processing approaches. In the first step, the essential boundary conditions for complete removal by means of the respective approaches are identified. Afterward, a representative demonstrator part with various macroscopic support structure designs will be LPBF-manufactured and tested with regard to a complete powder and support removability. Finally, based on the results, potentially suitable support structure designs for the respective approaches will be derived. The investigations are carried out on the example of the aluminum alloy AlSi10Mg.

Keywords: additive manufacturing, laser powder bed fusion, laser beam melting, selective laser melting, post processing, tool-free, wet chemical ablation, thermal deburring, aluminum alloy, AlSi10Mg

Procedia PDF Downloads 91

Authors: Bright Chukwunwike Uzuegbunam, Wojciech Paslawski, Hans Agren, Christer Halldin, Wolfgang Weber, Markus Luster, Thomas Arzberger, Behrooz Hooshyar Yousefi

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There is a need to develop a PET tracer that will enable to diagnosis and track the progression of Alpha-synucleinopathies (Parkinson’s disease [PD], dementia with Lewy bodies [DLB], multiple system atrophy [MSA]) in living subjects over time. Alpha-synuclein aggregates (a-syn), which are present in all the stages of disease progression, for instance, in PD, are a suitable target for in vivo PET imaging. For this reason, we have developed some promising a-syn tracers based on a disarylbisthiazole (DABTA) scaffold. The precursors are synthesized via a modified Hantzsch thiazole synthesis. The precursors were then radiolabeled via one- or two-step radiofluorination methods. The ligands were initially screened using a combination of molecular dynamics and quantum/molecular mechanics approaches in order to calculate the binding affinity to a-syn (in silico binding experiments). Experimental in vitro binding assays were also performed. The ligands were further screened in other experiments such as log D, in vitro plasma protein binding & plasma stability, biodistribution & brain metabolite analyses in healthy mice. Radiochemical yields were up to 30% - 72% in some cases. Molecular docking revealed possible binding sites in a-syn and also the free energy of binding to those sites (-28.9 - -66.9 kcal/mol), which correlated to the high binding affinity of the DABTAs to a-syn (Ki as low as 0.5 nM) and selectivity (> 100-fold) over Aβ and tau, which usually co-exist with a-synin some pathologies. The log D values range from 2.88 - 2.34, which correlated with free-protein fraction of 0.28% - 0.5%. Biodistribution experiments revealed that the tracers are taken up (5.6 %ID/g - 7.3 %ID/g) in the brain at 5 min (post-injection) p.i., and cleared out (values as low as 0.39 %ID/g were obtained at 120 min p.i. Analyses of the mice brain 20 min p.i. Revealed almost no radiometabolites in the brain in most cases. It can be concluded that in silico study presents a new venue for the rational development of radioligands with suitable features. The results obtained so far are promising and encourage us to further validate the DABTAs in autoradiography, immunohistochemistry, and in vivo imaging in non-human primates and humans.

Keywords: alpha-synuclein aggregates, alpha-synucleinopathies, PET imaging, tracer development

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Authors: María Reveles-Miranda, Daniella Pacheco-Catalán

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Sierra Papacal commissary is located north of Merida, Yucatan, México, where the indigenous Maya population predominates. Due to its location, the region has an elevation of fewer than 4.5 meters above sea level, with a high risk of flooding associated with storms and hurricanes and a high vulnerability of infrastructure and housing in the presence of strong gusts of wind. In environmental contingencies, the challenge is providing an autonomous electrical supply using renewable energy sources that cover vulnerable populations' health, food, and water pumping needs. To address this challenge, a hybrid energy storage module is proposed for the emergency photovoltaic (PV) system of the community shelter in Sierra Papacal, Yucatán, which combines high-energy-density batteries and high-power-density supercapacitors (SC) in a single module, providing a quick response to energy demand, reducing the thermal stress on batteries and extending their useful life. Incorporating SC in energy storage modules can provide fast response times to power variations and balanced energy extraction, ensuring a more extended period of electrical supply to vulnerable populations during contingencies. The implemented control strategy increases the module's overall performance by ensuring the optimal use of devices and balanced energy exploitation. The operation of the module with the control algorithm is validated with MATLAB/Simulink® and experimental tests.

Keywords: batteries, community shelter, environmental contingencies, hybrid energy storage, isolated photovoltaic system, supercapacitors

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Authors: E. T. El Shenawy, O. N. A. Esmail, Adel A. Elbaset, Hesham F. A. Hamed

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Generation of the electrical energy based on photovoltaic (PV) technology has been increased over the world due to either the continuous reduction in the traditional energy sources in addition to the pollution problems related to their usage, or the clean nature and safe usage of the PV technology. Also, PV systems can generate clean electricity in the site of use without any transmission, which can be considered cost effective than other generation systems. The performance of the PV system is highly affected by the amount of solar radiation incident on it. Completely or partially shaded PV systems can affect its output. The PV system can be shaded by trees, buildings, dust, incorrect system configuration, or other obstacles. The present paper studies the effect of the partial shading on the performance of a thin film PV module under climatic conditions of Cairo, Egypt. This effect was measured and evaluated according to practical measurement of the characteristic curves such as current-voltage and power-voltage for two identical PV modules (with and without shading) placed at the same time on one mechanical structure for comparison. The measurements have been carried out for the following shading patterns; half cell (bottom, middle, and top of the PV module); complete cell; and two adjacent cells. The results showed that partially shading the PV module changes the shapes of the I-V and P-V curves and produces more than one maximum power point, that can disturb the traditional maximum power point trackers. Also, the output power from the module decreased according to the incomplete solar radiation reaching the PV module due to shadow patterns. The power loss due shading was 7%, 22%, and 41% for shading of half-cell, one cell, and two adjacent cells of the PV module, respectively.

Keywords: I-V measurements, PV module characteristics, PV module power loss, PV module shading

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Authors: Kostandinos Katsamangas, Fawad Inam

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Graphene was dispersed using a tip sonicator and the effect of surfactants were analysed. Sodium Dodecyl Sulphate (SDS) and Polyvinyl Alcohol (PVA) were compared to observe whether or not they had any effect on any de-wrinkling, and secondly whether they aided to achieve better dispersions. There is a huge demand for wrinkle free graphene as this will greatly increase its usefulness in various engineering applications. A comprehensive literature on de-wrinkling graphene has been discussed. Low magnification Scanning Electronic Microscopy (SEM) was conducted to assess the quality of graphene de-wrinkling. The utilization of the PVA has a significant effect on de-wrinkling whereas SDS had minimal effect on the de-wrinkling of graphene.

Keywords: Graphene, de-wrinkling, dispersion, surfactants, scanning electronic microscopy

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Authors: Robert Long

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The results of a one-year study on the evolution of complexity, accuracy, and fluency (CAF) in the compositions of Japanese L2 university students throughout a semester are presented in this study. One goal was to determine if any improvement in writing abilities over this academic term had occurred, while another was to examine methods of editing. Participants had 30 minutes to write each essay with an additional 10 minutes allotted for editing. As for editing, participants were divided into two groups, one of which utilized an online grammar checker, while the other half self-edited their initial manuscripts. From the three different institutions, there was a total of 159 students. Research questions focused on determining if the CAF had evolved over the previous year, identifying potential variations in editing techniques, and describing the connections between the CAF dimensions. According to the findings, there was some improvement in accuracy (fewer errors) in all three of the measures), whereas there was a marked decline in complexity and fluency. As for the second research aim relating to the interaction among the three dimensions (CAF) and of possible increases in fluency being offset by decreases in grammatical accuracy, results showed (there is a logical high correlation with clauses and word counts, and mean length of T-unit (MLT) and (coordinate phrase of T-unit (CP/T) as well as MLT and clause per T-unit (C/T); furthermore, word counts and error/100 ratio correlated highly with error-free clause totals (EFCT). Issues of syntactical complexity had a negative correlation with EFCT, indicating that more syntactical complexity relates to decreased accuracy. Concerning a difference in error correction between those who self-edited and those who used an online grammar correction tool, results indicated that the variable of errors-free clause ratios (EFCR) had the greatest difference regarding accuracy, with fewer errors noted with writers using an online grammar checker. As for possible differences between the first and second (edited) drafts regarding CAF, results indicated there were positive changes in accuracy, the most significant change seen in complexity (CP/T and MLT), while there were relatively insignificant changes in fluency. Results also indicated significant differences among the three institutions, with Fujian University of Technology having the most fluency and accuracy. These findings suggest that to raise students' awareness of their overall writing development, teachers should support them in developing more complex syntactic structures, improving their fluency, and making more effective use of online grammar checkers.

Keywords: complexity, accuracy, fluency, writing

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Authors: Hayden R Schott, John M Felder III

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Introduction: Chronic lower extremity wounds in the diabetic and vasculopathic populations are associated with a high degree of morbidity.When wounds require more extensive treatment than can be offered by wound care centers, more aggressive solutions involve local tissue transfer and microsurgical free tissue transfer for achieving definitive soft tissue coverage. These procedures of autologous tissue transfer (ATT) offer resilient, soft tissue coverage of limb-threatening wounds and confer promising limb salvage rates. However, chronic osteomyelitis and recalcitrant soft tissue infections are common in severe diabetic foot wounds and serve to significantly complicate ATT procedures. Stimulan is a resorbable calcium sulfate antibiotic carrier. The use of stimulan antibiotic beads to treat chronic osteomyelitis is well established in the orthopedic and plastic surgery literature. In these procedures, the beads are placed beneath the skin flap to directly deliver antibiotics to the infection site. The purpose of this study was to quantify the success of Stimulan antibiotic beads in treating recalcitrant infections in patients with diabetic foot wounds receiving ATT. Methods: A retrospective review of clinical and demographic information was performed on patients who underwent ATT with the placement of Stimulan antibiotic beads for attempted limb salvage from 2018-21. Patients were analyzed for preoperative wound characteristics, demographics, infection recurrence, and adverse outcomes as a result of product use. The primary endpoint was 90 day infection recurrence, with secondary endpoints including 90 day complications. Outcomes were compared using basic statistics and Fisher’s exact tests. Results: In this time span, 14 patients were identified. At the time of surgery, all patients exhibited clinical signs of active infection, including positive cultures and erythema. 57% of patients (n=8) exhibited chronic osteomyelitis prior to surgery, and 71% (n=10) had exposed bone at the wound base. In 57% of patients (n=8), Stimulan beads were placed beneath a free tissue flap and beneath a pedicle tissue flap in 42% of patients (n=6). In all patients, Stimulan beads were only applied once. Recurrent infections were observed in 28% of patients (n=4) at 90 days post-op, and flap nonadherence was observed in 7% (n=1). These were the only Stimulan related complications observed. Ultimately, lower limb salvage was successful in 85% of patients (n=12). Notably, there was no significant association between the preoperative presence of osteomyelitis and recurrent infections. Conclusions: The use of Stimulanantiobiotic beads to treat recalcitrant infections in patients receiving definitive skin coverage of diabetic foot wounds does not appear to demonstrate unnecessary risk. Furthermore, the lack of significance between the preoperative presence of osteomyelitis and recurrent infections indicates the successful use of Stimulan to dampen infection in patients with osteomyelitis, as is consistent with the literature. Further research is needed to identify Stimulan as the significant contributor to infection treatment using future cohort and case control studies with more patients. Nonetheless, the use of Stimulan antibiotic beads in patients with diabetic foot wounds demonstrates successful infection suppression and maintenance of definitive soft tissue coverage.

Keywords: wound care, stimulan antibiotic beads, free tissue transfer, plastic surgery, wound, infection

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Authors: Richard Patrick Kabuye

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This study focuses on the addressing the enhancement of in-service training programs as a tool of transforming the existing traditional approaches of formal lectures/contact hours. This will be supported with a more versatile, robust, and remotely accessible means of mobile based e-learning, as a support tool for the traditional means. A combination of various factors in education and incorporation of the eLearning strategy proves to be a key factor in effective in-service education. Key factor needs to be factored in so as to maintain a credible co-existence of the programs, with the prevailing social, economic and political environments. Effective in-service education focuses on having immediate transformation of knowledge into practice for a good time period, active participation of attendees, enable before training planning, in training assessment and post training feedback training analysis which will yield knowledge to the trainers of the applicability of knowledge given out. All the above require a more robust approach to attain success in implementation. Incorporating mobile technology in eLearning will enable the above to be factored together in a more coherent manner, as it is evident that participants have to take time off their duties and attend to these training programs. Making it mobile, will save a lot of time since participants would be in position to follow certain modules while away from lecture rooms, get continuous program updates after completing the program, send feedback to instructors on knowledge gaps, and a wholly conclusive evaluation of the entire program on a learn as you work platform. This study will follow both qualitative and quantitative approaches in data collection, and this will be compounded incorporating a mobile eLearning application using Android.

Keywords: in service, training, mobile, e- learning, model

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Authors: Ni Tang, Jinping Zhang

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An effective and sustainable volunteer team is needed to create a more available blood supply system. In order to promote the sustainable development of blood donation in Zhejiang Province, China, a “three-exemption” policy was proposed in 2014: blood donors who received the National Award for unpaid blood donation may government-invested and funded parks, scenic spots and other places for free, visit non-profit medical institutions for free outpatient fees, and be exempted from urban public transportation fees. As the policy has been in place for seven years, this study evaluated the effectiveness of the policy by comparing the increasing rate of blood donation in Hangzhou (capital city of Zhejiang) before and after the policy using the intermittent time series analysis. The blood donation in Anhui, a Province near Zhejiang, was also compared as a negative control. Blood donation data from 2012 to 2018 were obtained from the donation center's official websites. The increasing rate of blood donation volume since 2012 in Hangzhou is 34.37 units/month, and after 2014, the increasing rate additionally increases 71.69 (p=0.1442), which indicating a statistically non-significant change after the policy. While as a negative control, in Anhui, the increasing rate of blood donation volume since 2012 is -163.3 unit/month, and the increasing rate additionally increases 167.2 (p=5.63e-07) after 2014. The result shows that the three-exemption policy had a certain level of impact on encouraging volunteers to donate blood, but the effect was not substantial. One possible reason for the ineffectiveness of the policy might be a lack of public awareness of the policy. On the other hand, this policy mainly waived unnecessary life expenses, such as fares and scenic entrance fees, and requires a certain number of blood donations, registration procedures, and blood donation certificates. Perhaps, reducing life-related expenses such as oil, water and electricity, could better attract people to participate in blood donation. This current study on the three-exemption policy provides a new direction for promoting people's blood donation. Incentive policies may require greater publicity and incentives. In order to better ensure the operation of the blood donation system, other policies, especially incentive policies, should be further explored.

Keywords: blood donation, policy, Zhejiang, unpaid blood donation, three-exemption policy

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Authors: T. S. Beerenahally, S. Amruthavalli, C. M. Munegowda, Leelavathi, Nagarathna

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Introduction: In majority of urban India, the health system is split between different authorities being responsible for the health care of urban population. We believe that, apart from poor awareness and financial barriers to care, there are other health system barriers which affect quality and access to care for people with diabetes. In this paper, we attempted to identify health system complexity that determines access to public health system for diabetes care in KG Halli, a poor urban neighborhood in Bengaluru. The KG Halli has been a locus of a health systems research from 2009 to 2015. Methodology: The source of data is from the observational field-notes written by research team as part of urban health action research project (UHARP). Field notes included data from the community and the public primary care center. The data was generated by the community health assistants and the other research team members during regular home visits and interaction with individuals who self-reported to be diabetic over four years as part of UHARP. Results: It emerged during data analysis that the patients were not keen on utilizing primary public health center for many reasons. Patient has felt that the service provided at the center was not integrated. There was lack of availability of medicines, with a regular stock out of medicines in a year and laboratory service for investigation was limited. Many of them said that the time given by the providers was not sufficient and there was also a feeling of providers not listening to them attentively. The power dynamics played a huge role in communication. Only the consultation was available for free of cost at the public primary care center. The patient had to spend for the investigations and the major portion for medicine. Conclusion: Diabetes is a chronic disease that poses an important emerging public health concern. Most of the financial burden is borne by the family as the public facilities have failed to provide free care in India. Our study indicated various factors including individual beliefs, stigma and financial constraints affecting compliance to diabetes care.

Keywords: diabetes care, disintegrated health system, quality of care, urban health

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Authors: S. Fröhlich, M. Herold, M. Allmer

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Early stage quantitative analysis of host cell protein (HCP) variations is challenging yet necessary for comprehensive bioprocess development. High resolution mass spectrometry (HRMS) provides a high-end technology for accurate identification alongside with quantitative information. Hereby we describe a flexible HRMS assay platform to quantify HCPs relevant in microbial expression systems such as E. Coli in both up and downstream development by means of MVDA tools. Cell pellets were lysed and proteins extracted, purified samples not further treated before applying the SMART tryptic digest kit. Peptides separation was optimized using an RP-UHPLC separation platform. HRMS-MSMS analysis was conducted on an Orbitrap Velos Elite applying CID. Quantification was performed label-free taking into account ionization properties and physicochemical peptide similarities. Results were analyzed using SIEVE 2.0 (Thermo Fisher Scientific) and SIMCA (Umetrics AG). The developed HRMS platform was applied to an E. Coli expression set with varying productivity and the corresponding downstream process. Selected HCPs were successfully quantified within the fmol range. Analysing HCP networks based on pattern analysis facilitated low level quantification and enhanced validity. This approach is of high relevance for high-throughput screening experiments during upstream development, e.g. for titer determination, dynamic HCP network analysis or product characterization. Considering the downstream purification process, physicochemical clustering of identified HCPs is of relevance to adjust buffer conditions accordingly. However, the technology provides an innovative approach for label-free MS based quantification relying on statistical pattern analysis and comparison. Absolute quantification based on physicochemical properties and peptide similarity score provides a technological approach without the need of sophisticated sample preparation strategies and is therefore proven to be straightforward, sensitive and highly reproducible in terms of product characterization.

Keywords: process analytical technology, mass spectrometry, process characterization, MVDA, pattern recognition

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Authors: Yuichi Anada

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Electrical properties of polymer solid is characterized by dielectric relaxation phenomenon. Complex permittivity shows a high dependence on frequency of external stimulation in the broad frequency range from 0.1mHz to 10GHz. The complex-permittivity dispersion gives us a lot of useful information about the molecular motion of polymers and the structure of polymer aggregates. However, the large dispersion of permittivity at low frequencies due to DC conduction of impurity ions often covers the dielectric relaxation in polymer solid. In experimental investigation, many researchers have tried to remove the DC conduction experimentally or analytically for a long time. On the other hand, our laboratory chose another way of research for this problem from the point of view of a reversal in thinking. The way of our research is to use the impurity ions in the DC conduction as a probe to detect the motion of polymer molecules and to investigate the structure of polymer aggregates. In addition to the complex permittivity, the electric modulus and the conductivity relaxation time are strong tools for investigating the ionic motion in DC conduction. In a non-crystalline part of melt-crystallized polymers, free spaces with inhomogeneous size exist between crystallites. As the impurity ions exist in the non-crystalline part and move through these inhomogeneous free spaces, the motion of ions reflects the microstructure of non-crystalline part. The ionic motion of impurity ions in poly(vinylidene fluoride) (PVDF) is investigated in this study. Frequency dependence of the loss permittivity of PVDF shows a characteristic of the direct current (DC) conduction below 1 kHz of frequency at 435 K. The electric modulus-frequency curve shows a characteristic of the dispersion with the single conductivity relaxation time. Namely, it is the Debye-type dispersion. The conductivity relaxation time analyzed from this curve is 0.00003 s at 435 K. From the plot of conductivity relaxation time of PVDF together with the other polymers against permittivity, it was found that there are two group of polymers; one of the group is characterized by small conductivity relaxation time and large permittivity, and another is characterized by large conductivity relaxation time and small permittivity.

Keywords: conductivity relaxation time, electric modulus, ionic motion, permittivity, poly(vinylidene fluoride), DC conduction

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