Search results for: barriers of reverse technology transfer

Authors: Tanveer Rasool, A. K. Dhiman

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The paper reports 2-D numerical study used to investigate the effect of changing working fluids with Prandtl numbers 0.71, 10 and 50 on the flow and convective heat transfer across an equilateral triangular cylinder placed in a horizontal channel with its apex facing the flow. Numerical results have been generated for fixed blockage ratio of 50% and for three Reynolds numbers of 50, 75, and 100 for each Prandtl numbers respectively. The studies show that for above range of Reynolds numbers, the overall drag coefficient is insensitive to the Prandtl number changes while as the heat transfer characteristics change drastically with changing Prandtl number of the working fluid. The results generated are in complete agreement with the previous literature available.

Keywords: Prandtl number, Reynolds number, drag coefficient, flow and isothermal patterns

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Authors: Andrew Anis Fakhrey Mosaad

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Objectives: Physiotherapy in the intensive care unit (ICU) improves patient outcomes. We aimed to determine the characteristics of physiotherapy practice and critical barriers to applying physiotherapy in ICUs. Materials and Methods: A 54-item survey for determining the characteristics physiotherapists and physiotherapy applications in the ICU was developed. The survey was electronically sent to potential participants through the Turkish Physiotherapy Association network. Sixty-five physiotherapists (47F and 18M; 23–52 years; ICU experience: 6.0±6.2 years) completed the survey. The data were analyzed using quantitative and qualitative methods. Results: The duration of ICU practice was 3.51±2.10 h/day. Positioning (90.8%), active exercises (90.8%), breathing exercises (89.2%), passive exercises (87.7%), and percussion (87.7%) were the most commonly used applications. The barriers were related to physiotherapists (low level of employment and practice, lack of shift); patients (unwillingness, instability, participation restriction); teamwork (lack of awareness and communication); equipment (inadequacy, non-priority to purchase); and legal (reimbursement, lack of direct physiotherapy access, non-recognition of autonomy) procedures. Conclusion: The most common interventions were positioning, active, passive, breathing exercises, and percussion. Critical barriers toward physiotherapy are multifactorial and related to physiotherapists, patients, teams, equipment, and legal procedures. Physiotherapist employment, service maintenance, and multidisciplinary teamwork should be considered for physiotherapy effectiveness in ICUs.

Keywords: intensive care units, physical therapy, physiotherapy, exercises

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Authors: Avijit Datta

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We have presented a phase control scheme in population transfer using chirped laser fields. A chirped pulse can do population transfer from one level to another level via adiabatic rapid passage accessible by one photon dipole transition. We propose to use a pair of phase-locked chirped pulses of the same frequency w(t) instead of a singly chirped-pulse frequency w(t). Simultaneous action of phase controlled interference in addition to rapid adiabatic passages due to chirped pulses lead to phase control over this population transfer dynamics. We have demonstrated the proposed phase control scheme over the population distribution from the initial level X(v=0,j=0) to C(v=2,j=1) level of hydrogen molecule using a pair of phase-locked and similarly chirped laser pulses. We have extended this two-level system to three-level 1+1 ladder system of hydrogen molecule from X level to final J(v=2,j=2) level via C intermediate level using two pairs of laser pulses having frequencies w(t) and w'(t) respectively and obtained laudable control over the population distribution among three levels. We also have presented some results of interference effects of w₁(t) and its third harmonics w₃(t).

Keywords: phase control, population transfer, chirped laser pulses, rapid adiabatic passage, laser-molecule interaction

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Authors: Ryan Brisbin, Hassan Harb, Justin Debow, Hrant Hratchian, Ryan Baxter

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Donor-Acceptor (DA) frameworks are crucial parts of any technology requiring charge transport. This type of behavior is ubiquitous across technologies from semi conductors to solar panels. Currently, most DA systems involve metallic components, but progressive research is being pursued to design fully organic DA systems to be used as both organic semi-conductors and light emitting diodes. These systems are currently comprised of conductive polymers and salts. However, little is known about the effect of various physical aspects (size, torsional angle, electron density) have on the act of reversible charge transfer. Herein, the effect of torsional angle on reductive stability in bis(imino)pyridines is analyzed using a combination of single crystal analysis and electro-chemical peak current ratios from cyclic voltammetry. The computed free energies of reduction and electron attachment points were also investigated through density functional theory and natural ionization orbital theory to gain greater understanding of the global effect torsional angles have on electron transfer in bis(imino)pyridines. Findings indicated that torsional angles are a multi-variable parameter affected by both local steric constraints and resonant electronic contributions. Local steric impacted torsional angles demonstrated a negligible effect on electrochemical reversibility, while resonant affected torsional angles were observed to significantly alter the electrochemical reversibility.

Keywords: cyclic voltammetry, bis(imino)pyridines, structure-activity relationship, torsional angles

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Authors: Rao Muhammad Afzal Khan

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Nano technology is emerging as a useful technology in nearly all areas of Science and Technology. Its role in medical imaging is attracting the researchers towards existing and new imaging modalities and techniques. This presentation gives an overview of the development of the work done throughout the world. Furthermore, it lays an idea into the scope of the future use of this technology for diagnosing different diseases. A comparative analysis has also been discussed with an emphasis to detect diseases, in general, and cancer, in particular.

Keywords: medical imaging, cancer detection, diagnosis, nano-imaging, nanotechnology

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Authors: Junting Xiang, Jörg Uwe Schlüter, Fei Duan

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The miniaturization of gas turbines promises many advantages. Miniature gas turbines can be used for local power generation or the propulsion of small aircraft, such as UAV and MAV. However, experience shows that the miniaturization of conventional gas turbines, which are optimized at their current large size, leads to a substantial loss of efficiency and performance at smaller scales. This may be due to a number of factors, such as the Reynolds-number effect, the increased heat transfer, and manufacturing tolerances. In the present work, we focus on computational investigations of the Reynolds number effect and the wall heat transfer on the performance of axial compressor during its size change. The NASA stage 35 compressors are selected as the configuration in this study and Computational Fluid Dynamics (CFD) is used to carry out the miniaturization process and simulations. We perform parameter studies on the effect of Reynolds number and wall thermal conditions. Our results indicate a decrease of efficiency, if the compressor is miniaturized based on its original geometry due to the increase of viscous effects. The increased heat transfer through wall has only a small effect and will actually benefit compressor performance based on our study.

Keywords: axial compressor, CFD, heat transfer, miniature gas turbines, Reynolds number

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Authors: Alireza Abbassi Monjezi, Mohammad Hasan Shaheed

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Flood, caused by excessive rainfall, monsoon, cyclone and tsunami is a common disaster in many countries of the world especially sea connected low-lying countries. A stand-alone self-powered water filtration module for decontamination of floodwater has been designed and modeled. A combination forward osmosis – low pressure reverse osmosis (FO-LPRO) system powered by solar photovoltaic-thermal (PVT) energy is investigated which could overcome the main barriers to water supply for remote areas and ensure off-grid filtration. The proposed system is designed to be small scale and portable to provide on-site potable water to communities that are no longer themselves mobile nor can be reached quickly by the aid agencies. FO is an osmotically driven process that uses osmotic pressure gradients to drive water across a controlled pore membrane from a feed solution (low osmotic pressure) to a draw solution (high osmotic pressure). This drops the demand for high hydraulic pressures and therefore the energy demand. There is also a tendency for lower fouling, easier fouling layer removal and higher water recovery. In addition, the efficiency of the PVT unit will be maximized through freshwater cooling which is integrated into the system. A filtration module with the capacity of 5 m3/day is modeled to treat floodwater and provide drinking water. The module can be used as a tool for disaster relief, particularly in the aftermath of flood and tsunami events.

Keywords: flood resilience, membrane desalination, portable water treatment, solar energy

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Authors: Marzieh Khezerloo, Lyazid Djenidi

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Owing to wide range of the micro-device applications, the problems of mixing at small scales is of significant interest. Also, because most of the processes produce heat, it is needed to develop and implement strategies for heat removal in these devices. There are many studies which focus on the effect of roughness or suction on heat transfer performance, separately, although it would be useful to take advantage of these two methods to improve heat transfer performance. Unfortunately, there is a gap in this area. The present numerical study is carried to investigate the combined effects of roughness and wall suction on heat transfer performance of a laminar channel flow; suction is applied on the top and back faces of the roughness element, respectively. The study is carried out for different Reynolds numbers, different suction rates, and various locations of suction area on the roughness. The flow is assumed two dimensional, incompressible, laminar, and steady state. The governing Navier-Stokes equations are solved using ANSYS-Fluent 18.2 software. The present results are tested against previous theoretical results. The results show that by adding suction, the local Nusselt number is enhanced in the channel. In addition, it is shown that by applying suction on the bottom section of the roughness back face, one can reduce the thickness of thermal boundary layer, which leads to an increase in local Nusselt number. This indicates that suction is an effective means for improving the heat transfer rate (suction by controls the thickness of thermal boundary layer). It is also shown that the size and intensity of vortical motion behind the roughness element, decreased with an increasing suction rate, which leads to higher local Nusselt number. So, it can be concluded that by using suction, strategically located on the roughness element, one can control both the recirculation region and the heat transfer rate. Further results will be presented at the conference for coefficient of drag and the effect of adding more roughness elements.

Keywords: heat transfer, laminar flow, numerical simulation, roughness, suction

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Authors: Khwaja Bahman Qaderi, Noorullah Rafiqee

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Background: With today's increasing Internet users, e-commerce has become a viable model for strengthening relationships between sellers, entrepreneurs, and consumers due to its speed, efficiency, and cost reduction. Agriculture is the economic backbone for 80 percent of the Afghan population. According to MCIT statistics, there are currently around 10 million internet users in Afghanistan. With this data, it was expected that Afghan people should have utilized e-commerce in their agricultural aspects, although it appears to be less used. Objective: This study examines the scope of e-commerce in Afghanistan's agriculture enterprises, how they harness the potential of internet users, and what obstacles they face in implementing e-commerce in their businesses. Method: The study distributed a 39-question questionnaire to agribusinesses in five different zones of Afghanistan. After extracting the responses and excluding the incomplete questionnaires, 280 were included in the analysis step to perform a non-parametric sign test. Result: E-commerce in Afghanistan faces four major political, economic, Internet, and technological obstacles, and no company in the country has implemented e-commerce. In addition, e-commerce is still in its infancy among agricultural companies in the country. Internet use is still primarily limited to email and sharing product images on Facebook & Instagram for advertising purposes. There are no companies that conduct international transactions via the Internet. Conclusion: This study contributes to knowing the challenges and barriers that the agriculture e-commerce faces in Afghanistan to find the effective solutions to use the capacity of internet users in the country and increase the sales rate of agricultural products through the Internet.

Keywords: E-commerce, barriers and challenges, agriculture companies, Afghanistan

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Authors: Radouane Elbahjaoui, Hamid El Qarnia

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The present work aims to investigate numerically the thermal and flow characteristics of a rectangular latent heat storage unit (LHSU) during the melting process of a phase change material (PCM). The LHSU consists of a number of vertical and identical plates of PCM separated by rectangular channels. The melting process is initiated when the LHSU is heated by a heat transfer fluid (HTF: water) flowing in channels in a downward or upward direction. The proposed study is motivated by the need to optimize the thermal performance of the LHSU by accelerating the charging process. A mathematical model is developed and a fixed-grid enthalpy formulation is adopted for modeling the melting process coupling with convection-conduction heat transfer. The finite volume method was used for discretization. The obtained numerical results are compared with experimental, analytical and numerical ones found in the literature and reasonable agreement is obtained. Thereafter, the numerical investigations were carried out to highlight the effects of the HTF flow direction and the aspect ratio of the PCM slabs on the heat transfer characteristics and thermal performance enhancement of the LHSU.

Keywords: PCM, TES, LHSU, melting

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Authors: M. Yousaf, S. Usman

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The present study focused on the investigation of the effects of roughness elements on heat transfer during natural convection in a rectangular cavity using a numerical technique. Roughness elements were introduced on the bottom hot wall with a normalized amplitude (A*/H) of 0.1. Thermal and hydrodynamic behavior was studied using a computational method based on Lattice Boltzmann method (LBM). Numerical studies were performed for a laminar natural convection in the range of Rayleigh number (Ra) from 103 to 106 for a rectangular cavity of aspect ratio (L/H) 2 with a fluid of Prandtl number (Pr) 1.0. The presence of the sinusoidal roughness elements caused a minimum to the maximum decrease in the heat transfer as 7% to 17% respectively compared to the smooth enclosure. The results are presented for mean Nusselt number (Nu), isotherms, and streamlines.

Keywords: natural convection, Rayleigh number, surface roughness, Nusselt number, Lattice Boltzmann method

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Authors: Sujit K. Basak, Simon Collin

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The aim of this paper is to examine the technology access and use on the affecting social integration of local students at university. This aim is achieved by designing a structural equation modeling (SEM) in terms of integration with peers, integration with faculty, faculty support and on the other hand, examining the socio demographic impact on the technology access and use. The collected data were analyzed using the WarpPLS 5.0 software. This study was survey based and it was conducted at a public university in Canada. The results of the study indicated that technology has a strong impact on integration with faculty, faculty support, but technology does not have an impact on integration with peers. However, the social demographic has also an impact on the technology access and use.

Keywords: faculty, integration, peer, technology access and use

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Authors: Abdul Murad Zainal Abidin, Azahar Mohd, Nor Idayu Arifin, Siti Nor Azila Khalid, Mohd Julzaha Zahari Mohamad Yusof

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A thermoelectric cooler (TEC) is an electronic component that uses ‘peltier’ effect to create a temperature difference by transferring heat between two electrical junctions of two different types of materials. TEC can also be used for heating by reversing the electric current flow and even power generation. A heat flow meter (HFM) is an equipment for measuring thermal conductivity of building materials. During the test, water is used as heat transfer medium to cool the HFM. The existing re-circulating cooler in the market is very costly, and the alternative is to use piped tap water to extract heat from HFM. However, the tap water temperature is insufficiently low to enable heat transfer to take place. The operating temperature for isothermal plates in the HFM is 40°C with the range of ±0.02°C. When the temperature exceeds the operating range, the HFM stops working, and the test cannot be conducted. The aim of the research is to develop a low-cost but energy-efficient TEC prototype that enables heat transfer without compromising the function of the HFM. The objectives of the research are a) to identify potential of TEC as a cooling device by evaluating its cooling rate and b) to determine the amount of water savings using TEC compared to normal tap water. Four (4) peltier sets were used, with two (2) sets used as pre-cooler. The cooling water is re-circulated from the reservoir into HFM using a water pump. The thermal conductivity readings, the water flow rate, and the power consumption were measured while the HFM was operating. The measured data has shown decrease in average cooling temperature difference (ΔTave) of 2.42°C and average cooling rate of 0.031°C/min. The water savings accrued from using the TEC is projected to be 8,332.8 litres/year with the application of water re-circulation. The results suggest the prototype has achieved required objectives. Further research will include comparing the cooling rate of TEC prototype against conventional tap water and to optimize its design and performance in terms of size and portability. The possible application of the prototype could also be expanded to portable storage for medicine and beverages.

Keywords: energy efficiency, thermoelectric cooling, pre-cooling device, heat flow meter, sustainable technology, thermal conductivity

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Authors: William Middleton, Nodumo Zulu, Sue Harrison

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Open raceway ponds are currently the most used system for the commercial cultivation of algal biomass, as it is a cost-effective means of production. However, raceway ponds suffer from lower algal productivity when compared to closed photobioreactors. This is due to poor gas exchange between the fluid and the atmosphere. Carbon dioxide (CO₂) mass transfer is a large concern in the production of algae in raceway pond systems. The utilization of atmospheric CO₂ does not support maximal growth; however, CO₂ supplementation in the form of flue gas or concentrated CO₂ is not cost-effective. The introduction of slopes into the raceway system presents a possible improvement to the mass transfer from the air, as seen in previous work conducted at CeBER. Slopes improve turbulence (decreasing the concentration gradient of dissolved CO₂) and can cause air entrainment (allowing for greater surface area and contact time between the air and water). This project tests the findings of previous studies conducted in an indoor lab-scale raceway on a larger scale under outdoor conditions. The addition of slopes resulted in slightly increased CO₂ mass transfer as well as algal growth rate and productivity. However, there were reductions in energy consumption and average fluid velocity in the system. These results indicate a potential to improve the economic feasibility of algal biomass production, but further economic assessment would need to be carried out.

Keywords: algae, raceway ponds, mass transfer, algal culture, biotechnology, reactor design

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Authors: Natasha Bhate

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Contraception is important in helping to reduce maternal and infant mortality rates by allowing women to control the number and spacing in-between their children. It also reduces the need for unsafe abortions. Women worldwide use contraception; however, the contraceptive prevalence rate is still relatively low in Central American countries like Guatemala. There is also an unmet need for contraception in Guatemala, which is more significant in rural, indigenous women due to barriers preventing contraceptive use. The study objective was to investigate and analyse the current barriers women face, in Guatemala, Panajachel and the surrounding areas, in using contraception, with a view of identifying ways to overcome these barriers. This included exploring the contraceptive barriers women believe exist and the influence of males in contraceptive decision making. The study took place at a charity in Panajachel, Guatemala, and had a cross-sectional, qualitative design to allow an in-depth understanding of information gathered. This particular study design was also chosen to help inform the charity with qualitative research analysis, in view of their intent to create a local reproductive health programme. A semi-structured interview design, including photo facilitation to improve cross-cultural communication, with interpreter assistance, was utilized. A pilot interview was initially conducted with small improvements required. Participants were recruited through purposive and convenience sampling. The study host at the charity acted as a gatekeeper; participants were identified through attendance of the charity’s women’s-initiative programme workshops. 20 participants were selected and agreed to study participation with two not attending; a total of 18 participants were interviewed in June 2017. Interviews were audio-recorded and data were stored on encrypted memory sticks. Framework analysis was used to analyse the data using NVivo11 software. The University of Leeds granted ethical approval for the research. Religion, language, the community, and fear of sickness were examples of existing contraceptive barrier themes recognized by many participants. The influence of men was also an important barrier identified, with themes of machismo and abuse preventing contraceptive use in some women. Women from more rural areas were believed to still face barriers which some participants did not encounter anymore, such as distance and affordability of contraceptives. Participants believed that informative workshops in various settings were an ideal method of overcoming existing contraceptive barriers and allowing women to be more empowered. The involvement of men in such workshops was also deemed important by participants to help reduce their negative influence in contraceptive usage. Overall, four recommendations following this study were made, including contraceptive educational courses, a gender equality campaign, couple-focused contraceptive workshops, and further qualitative research to gain a better insight into men’s opinions regarding women using contraception.

Keywords: barrier, contraception, machismo, religion

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Authors: Omid Azimaraghi, Noushin Khazaei

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Background: Fluid therapy is an important aspect of the perioperative period and a major challenge for anesthesiologists. To authors best knowledge, there is a lack of strong guidance and evidence regarding the optimal approach to fluid therapy. Therefore a variety of medical devices have been introduced to help physicians. In this study, we aimed to evaluate the effectiveness of pleth variability index in guiding fluid therapy in different patient positions. Materials and Methods: Inclusion criteria consisted of patients aged 18-50 years old and classified as American Society of Anesthesiologists physical status I and II, who were candidates for elective thyroidectomy surgery. In total, 36 patients meeting the inclusion criteria were enrolled in the study. After induction of anesthesia and start of mechanical ventilation Pleth variability index was measured in the supine position, then patients were placed in Trendelenburg and reverse Trendelenburg position (30 degrees, 5 minutes); Pleth Variability Index has measured again in the mentioned positions. Results: Mean PVI (Pleth Variability Index) in the supine position was 14.3 ± 3.7 in comparison to 21.5 ± 4.3 in the reverse Trendelenburg position. The mean PVI in Trendelenburg position was 9.1 ± 2.0 in Trendelenburg position (p < 0.05). Conclusion: In conclusion, we found that Pleth Variability Index varies with patient position and this should be taken into account when using this index during fluid therapy.

Keywords: fluid therapy, Pleth Variability Index, position, surgery

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Authors: Sirine Sayed, Mahrez Ait Mohammed, Mourad Nachtane, Abdelwahed Barkaoui, Khalid Bouziane, Mostapha Tarfaoui

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This study addresses a critical challenge in transitioning to a hydrogen-based economy by introducing and validating a one-dimensional (1D) tool for modelling hydrogen permeability through hybrid materials, focusing on tank applications. The model developed integrates rigorous experimental validation, published data, and advanced computational modelling using the PanDiffusion framework, significantly enhancing its validity and applicability. By elucidating complex interactions between material properties, storage system configurations, and operational parameters, the tool demonstrates its capability to optimize design and operational parameters in real-world scenarios, as illustrated through a case study of hydrogen leakage. This comprehensive approach to assessing hydrogen permeability contributes significantly to overcoming key barriers in hydrogen infrastructure development, potentially accelerating the widespread adoption of hydrogen technology across various industrial sectors and marking a crucial step towards a more sustainable energy future.

Keywords: hydrogen storage, composite tank, permeability modelling, PanDiffusion, energy carrier, transportation technology

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Authors: Nishiyama Toshiaki, Tadayuki Kyountani, Nguyen Huu Phuc, Shigeyuki Haruyama, Oke Oktavianty

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It is important to clarify the company’s core technology in product development process to strengthen their power in providing technology that meets the customer requirement. QFD method is adopted to clarify the core technology through identifying the high element technologies that are related to the voice of customer, and offer the most delightful features for customer. AHP is used to determine the importance of evaluating factors. A case study was conducted by using this approach in Japan’s Monozukuri Company (so called manufacturing company) to clarify their core technology based on customer requirements.

Keywords: core technology, QFD, voices of customer, analysis procedure

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Authors: Wael Al-Kouz

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Numerical simulations to study heat transfer and flow characteristics of mixed convection for rarefied gas in a square enclosure are utilized. Effect of the geometry in terms of the location of the inlet and exit openings are investigated. Moreover, effect of Knudsen number on the flow and heat transfer characteristics is illustrated and discussed. Results of the simulations show that there is a configuration that yields better heat transfer. This configuration is found to be the geometry in which the inlet opening is in the top left corner and the exit opening is at the bottom right corner. In addition, it is found that by increasing Knudsen number, Nusselt number will decrease.

Keywords: Knudsen number, mixed convection, rarefied gas, square enclosure

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Authors: J. Munuzuri, L. Onieva, J. Guadix, P. Cortes

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The aeronautical sector represents the main source of industrial development in the South of the Iberian Peninsula, with the establishment of key players like Embraer in Alentejo or Airbus in Andalusia. Subsequently, the economic promotion policies implemented in both neighbouring regions seek to consolidate a trans-border aeronautical cluster to gain critical mass and seek synergies between companies and research centres. The first step of the proposed scheme entails the identification of common interests shared by companies, technological centres and university research groups in both regions. This involves determining the specific type of activities carried out at the different companies established in the two regions (ranging from OEMs to SMEs) and also building a catalogue of available infrastructures and skills on the side of research centres and universities. The results of this first step reveal potential one-to-one partnerships, and also highlight the aggregate strengths and needs of the two regions within the aeronautical sector, taking into account both the current scenario and its expected evolution. The second step of the scheme focuses on the particularly relevant companies identified in the first step, and consists of the completion of in-depth technological audits liable to suggest potential development actions or R&D projects in those companies, counting when possible on the capabilities shown by other members of the cluster. These technological audits follow a three-round process aimed at identifying specific needs, validating those identifications and suggesting possible actions to be taken. The final objective of this methodology is to enhance the economic activity in the aeronautical sector in both regions, always with an innovative perspective. The success of the scheme should be measured in terms of partnerships created, R&D projects initiated, and spin-off companies generated.

Keywords: aeronautical sector, technological audits, technology transfer, trans-border cluster

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Authors: Olena Mayboroda, Angel Gonzalez Benito, Jonathan Sabate Del Rio, Marketa Svobodova, Sandra Julich, Herbert Tomaso, Ciara K. O'Sullivan, Ioanis Katakis

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DNA amplification is required for most molecular diagnostic applications but conventional PCR has disadvantages for field testing. Isothermal amplification techniques are being developed to respond to this problem. One of them is the Recombinase Polymerase Amplification (RPA) that operates at isothermal conditions without sacrificing specificity and sensitivity in easy-to-use formats. In this work RPA was used for the optical detection of solid-phase amplification of the potential biowarfare agent Yersinia pestis. Thiolated forward primers were immobilized on the surface of maleimide-activated microtitre plates for the quantitative detection of synthetic and genomic DNA, with elongation occurring only in the presence of the specific template DNA and solution phase reverse primers. Quantitative detection was achieved via the use of biotinylated reverse primers and post-amplification addition of streptavidin-HRP conjugate. The overall time of amplification and detection was less than 1 hour at a constant temperature of 37oC. Single-stranded and double-stranded DNA sequences were detected achieving detection limits of 4.04*10-13 M and 3.14*10-16 M, respectively. The system demonstrated high specificity with negligible responses to non-specific targets.

Keywords: recombinase polymerase amplification, Yersinia pestis, solid-phase detection, ELONA

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Authors: Jason Clarke, Michaela Porubanova, Angela Mazzoli, Gulsah Kut

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What accounts for our perception that time inexorably passes in one direction, from the past to the future, the so-called arrow of time, given that the laws of physics permit motion in one temporal direction to also happen in the reverse temporal direction? Modern physics says that the reason for time’s unidirectional physical arrow is the relationship between time and entropy, the degree of disorder in the universe, which is evolving from low entropy (high order; thermal disequilibrium) toward high entropy (high disorder; thermal equilibrium), the second law of thermodynamics. Accordingly, our perception of the direction of time, from past to future, is believed to emanate as a result of the natural evolution of entropy from low to high, with low entropy defining our notion of ‘before’ and high entropy defining our notion of ‘after’. Here we explored this proposed relationship between entropy and the perception of time’s arrow. We predicted that if the brain has some mechanism for detecting entropy, whose output feeds into processes involved in constructing our perception of the direction of time, presentation of violations to the expectation that low entropy defines ‘before’ and high entropy defines ‘after’ would alert this mechanism, leading to measurable behavioral effects, namely a disruption in duration perception. To test this hypothesis, participants were shown briefly-presented (1000 ms or 500 ms) computer-generated visual dynamic events: novel 3D shapes that were seen either to evolve from whole figures into parts (low to high entropy condition) or were seen in the reverse direction: parts that coalesced into whole figures (high to low entropy condition). On each trial, participants were instructed to reproduce the duration of their visual experience of the stimulus by pressing and releasing the space bar. To ensure that attention was being deployed to the stimuli, a secondary task was to report the direction of the visual event (forward or reverse motion). Participants completed 60 trials. As predicted, we found that duration reproduction was significantly longer for the high to low entropy condition compared to the low to high entropy condition (p=.03). This preliminary data suggests the presence of a neural mechanism that detects entropy, which is used by other processes to construct our perception of the direction of time or time’s arrow.

Keywords: time perception, entropy, temporal illusions, duration perception

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Authors: Akanksha Singh, Mahesh Kumar, Shailesh N. Sharma

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Semiconductor quantum dots (QDs) such as CdSe, CdS, InP, etc. have gained significant interest in the recent years due to its application in various fields such as LEDs, solar cells, lasers, biological markers, etc. The interesting feature of the QDs is their tunable band gap. The size of the QDs can be easily varied by varying the synthesis parameters which change the band gap. One of the limitations with II-VI semiconductor QDs is their biological application. The use of cadmium makes them unsuitable for biological applications. III-V QD such as InP overcomes this problem as they are structurally robust because of the covalent bonds which do not allow the ions to leak. Also, InP QDs has large Bohr radii which increase the window for the quantum confinement effect. The synthesis of InP QDs is difficult and time consuming. Authors have synthesized InP using a novel, quick synthesis method which utilizes trioctylphosphine as a source of phosphorus. In this work, authors have made InP composites with P3HT(Poly(3-hexylthiophene-2,5-diyl))polymer(organic-inorganic hybrid material) and gold nanoparticles(metal-semiconductor composites). InP-P3HT shows FRET phenomenon whereas InP-Au shows charge transfer mechanism. The synthesized InP QDs has an absorption band at 397 nm and PL peak position at 491 nm. The band gap of the InP QDs is 2.46 eV as compared to the bulk band gap of InP i.e. 1.35 eV. The average size of the QDs is around 3-4 nm. In order to protect the InP core, a shell of wide band gap material i.e. ZnS is coated on the top of InP core. InP-P3HT composites were made in order to study the charge transfer/energy transfer phenomenon between them. On adding aliquots of P3HT to InP QDs solution, the P3HT PL increases which can be attributed to the dominance of Förster energy transfer between InP QDs (donor) P3HT polymer (acceptor). There is a significant spectral overlap between the PL spectra of InP QDs and absorbance spectra of P3HT. But in the case of InP-Au nanocomposites, significant charge transfer was seen from InP QDs to Au NPs. When aliquots of Au NPs were added to InP QDs, a decrease in the PL of the InP QDs was observed. This is due to the charge transfer from the InP QDs to the Au NPs. In the case of metal semiconductor composites, the enhancement and quenching of QDs depend on the size of the QD and the distance between the QD and the metal NP. These two composites have different phenomenon between donor and acceptor and hence can be utilized for two different applications. The InP-P3HT composite can be utilized for LED devices due to enhancement in the PL emission (FRET). The InP-Au can be utilized efficiently for photovoltaic application owing to the successful charge transfer between InP-Au NPs.

Keywords: charge transfer, FRET, gold nanoparticles, InP quantum dots

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Authors: Rojean Ghafariasar, Leili Nosrati

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The article introduces the categories and characteristics of cross-design, respectively, between industry and industry designers, artists, brands and brands, science, technology, and fashion. It focuses on the combination of technology and fashion cross-design methods, corresponding case studies on the combination of new technology fabrics, fashion design, smart devices, and also 3D printing technology, emphasizing the integration and application value of technology and fashion. The document also introduces design elements into fashion design through scientific and technological intelligence, promoting fashion innovation as well as research and development of new materials and functions, and incubates an ecosystem for the fashion industry through science and technology.

Keywords: fashion, design, industrial design, crossover design

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Authors: Triem T. Hoang

Abstract:

Loop heat pipes (LHPs) are two-phase capillary-pumped heat transports. An appropriate working fluid is selected for the intended application temperature range. A closed-loop is evacuated to a high vacuum, back-filled partially with the working fluid, and then hermetically sealed under the fluid own pressure. Heat from a heat source conducts through the evaporator casing to vaporize liquid on the outer surface of the wick structure inside the evaporator. The generated vapor is compelled to vent out of the evaporator and into the vapor line for transport to the condenser assembly. There, heat is removed and rejected to a heat sink to condensed vapor back to liquid. The liquid exits the condenser and travels in the liquid line to return to the evaporator to complete the cycle. The circulation of fluid, and thus the heat transport in the LHP, is accomplished entirely by capillary action. The LHP contains no mechanical moving part to wear out or break down and, therefore possesses, reliability and a long life even without maintenance. In this paper, the author not only attempts to introduce the LHP technology in simplistic terms to those who are not familiar with it but also provides necessary technical information to potential users for the proper design and analysis of the LHP system.

Keywords: two-phase heat transfer, loop heat pipe, capillary pumped technology, thermal-fluid modeling

Procedia PDF Downloads 140

Authors: B. Remya Mohan, Kamal Bijlani, R. Jayakrishnan

Abstract:

Visualization in an educational context provides the learner with visual means of information. Conceptualizing certain circumstances such as consequences of smoking can be done more effectively with the help of the technology, Augmented Reality (AR). It is a new methodology for effective learning. This paper proposes an approach on how AR based on Marker Technology simulates the harmful effects of smoking and its consequences using Unity 3D game engine. The study also illustrates the impact of AR technology on students for better learning. AR technology can be used as a method to improve learning.

Keywords: augmented reality, marker technology, multi-platform, virtual buttons

Procedia PDF Downloads 578

Authors: Maurice Brogly, Edwige Privas, Rajesh K. Gajendran, Sophie Bistac

Abstract:

Anti-sticky coatings based on perfluoroalkoxy (PFA) coatings are widely used in food processing industry especially for bread making. Their tribological performance, such as low friction coefficient, low surface energy and high heat resistance, make them an appropriate choice for anti-sticky coating application in moulds for food processing industry. This study is dedicated to evidence the transfer of contaminants from the coating due to wear and thermal ageing of the mould. The risk of contamination is induced by the damage of the coating by bread crust during the demoulding stage. The study focuses on the wear resistance and potential transfer of perfluorinated polymer from the anti-sticky coating. Friction between perfluorinated coating and bread crust is modeled by a tribological pin-on-disc test. The cellular nature of the bread crust is modeled by a polymer foam. FTIR analysis of the polymer foam after friction allow the evaluation of the transfer from the perfluorinated coating to polymer foam. Influence of thermal ageing on the physical, chemical and wear properties of the coating are also investigated. FTIR spectroscopic results show that the increase of PFA transfer onto the foam counterface is associated to the decrease of the friction coefficient. Increasing lubrication by film transfer results in the decrease of the friction coefficient. Moreover increasing the friction test parameters conditions (load, speed and sliding distance) also increase the film transfer onto the counterface. Thermal ageing increases the hydrophobic character of the PFA coating and thus also decreases the friction coefficient.

Keywords: fluorobased polymer coatings, FTIR spectroscopy, non-stick food moulds, wear and friction

Procedia PDF Downloads 331

Authors: Luvindran Sugumaran, Mohd Nashrul Mohd Zubir, Kazi Md Salim Newaz, Tuan Zaharinie Tuan Zahari, Suazlan Mt Aznam, Aiman Mohd Halil

Abstract:

Due to the rapid advancement of integrated circuits and the increasing trend towards miniaturizing electronic devices, the amount of heat produced by electronic devices has consistently exceeded the maximum limit for heat dissipation. Currently, the two-phase cooling technique based on phase change pool boiling heat transfer has received a lot of attention because of its potential to fully utilize the latent heat of the fluid and produce a highly effective heat dissipation capacity while keeping the equipment's operating temperature within an acceptable range. There are numerous strategies available for the alteration of heating surfaces, but to find the best, simplest, and most dependable one remains a challenge. Lately, surface texturing via laser ablation has been used in a variety of investigations, demonstrating its significant potential for enhancing the pool boiling heat transfer performance. In this research, the nucleate pool boiling heat transfer performance of laser-textured copper surfaces of different patterns was investigated. The bare copper surface serves as a reference to compare the performance of laser-structured surfaces. It was observed that the heat transfer coefficients were increased with the increase of surface area ratio and the ratio of the peak-to-valley height of the microstructure. Laser machined grain structure produced extra nucleation sites, which ultimately caused the improved pool boiling performance. Due to an increase in nucleation site density and surface area, the enhanced nucleate boiling served as the primary heat transfer mechanism. The pool boiling performance of the laser-textured copper surfaces is superior to the bare copper surface in all aspects.

Keywords: heat transfer coefficient, laser texturing, micro structured surface, pool boiling

Procedia PDF Downloads 92

Authors: Varun Goel

Abstract:

Solar energy is a good option among renewable energy resources due to its easy availability and abundance. The simplest and most efficient way to utilize solar energy is to convert it into thermal energy and this can be done with the help of solar collectors. The thermal performance of such collectors is poor due to less heat transfer from the collector surface to air. In this work, experimental investigations of single pass solar air heater having triangular duct and provided with roughness element on the underside of the absorber plate. V-shaped ribs are used for investigation having three different values of relative roughness pitch (p/e) ranges from 4-16 for a fixed value of angle of attack (α), relative roughness height (e/Dh) and a relative gap distance (d/x) values are 60°, 0.044 and 0.60 respectively. Result shows that considerable augmentation in heat transfer has been obtained by providing roughness.

Keywords: artificial roughness, solar air heater, triangular duct, V-shaped ribs

Procedia PDF Downloads 452

Authors: Trevor E. Davis, Isaac Cassar, Yi-Kai Lo, Wentai Liu

Abstract:

This study models the use of transcutaneous electrical nerve stimulation on skin with a disk electrode in order to simulate tissue damage. The current density distribution above a disk electrode is known to be a dynamic and non-uniform quantity that is intensified at the edges of the disk. The non-uniformity is subject to change through using various electrode geometries or stimulation methods. One of these methods known as edge-retarded stimulation has shown to reduce this edge enhancement. Though progress has been made in modeling the behavior of a disk electrode, little has been done to test the validity of these models in simulating the actual heat transfer from the electrode. This simulation uses finite element software to couple the injection of current from a disk electrode to heat transfer described by the Pennesbioheat transfer equation. An example application of this model is studying an experimental form of stimulation, known as edge-retarded stimulation. The edge-retarded stimulation method will reduce the current density at the edges of the electrode. It is hypothesized that reducing the current density edge enhancement effect will, in turn, reduce temperature change and tissue damage at the edges of these electrodes. This study tests this hypothesis as a demonstration of the capabilities of this model. The edge-retarded stimulation proved to be safer after this simulation. It is shown that temperature change and the fraction of tissue necrosis is much greater in the square wave stimulation. These results bring implications for changes of procedures in transcutaneous electrical nerve stimulation and transcutaneous spinal cord stimulation as well.

Keywords: bioheat transfer, electrode, neuroprosthetics, TENS, transcutaneous stimulation

Procedia PDF Downloads 240