Search results for: Katharina Wick
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 49

Search results for: Katharina Wick

49 Experimental Testing of Solar Still with Movable Inclined Surface and Equipped with Wick

Authors: Ahmed N. Shmroukh

Abstract:

This study examined a new solar still equipped with a movable inclined back, and this back is covered with a wick for seawater desalination. The tested backside inclination angles were 105, 125 and 160, respectively. The wick helped in increasing the seawater evaporation rate by increasing the evaporation surface area allowed for seawater in the still basin. The proposed modified solar still was compared with the conventional simple still. The results showed that the daily produced desalinated water of the modified solar still with angles 105, 125 and 160 increased by approximately 13.7%, 27.9%, and 39.2%, respectively, compared with the conventional solar still.

Keywords: solar still, inclined still, porous materials, Wick

Procedia PDF Downloads 36
48 Solving Stochastic Eigenvalue Problem of Wick Type

Authors: Hassan Manouzi, Taous-Meriem Laleg-Kirati

Abstract:

In this paper we study mathematically the eigenvalue problem for stochastic elliptic partial differential equation of Wick type. Using the Wick-product and the Wiener-Ito chaos expansion, the stochastic eigenvalue problem is reformulated as a system of an eigenvalue problem for a deterministic partial differential equation and elliptic partial differential equations by using the Fredholm alternative. To reduce the computational complexity of this system, we shall use a decomposition-coordination method. Once this approximation is performed, the statistics of the numerical solution can be easily evaluated.

Keywords: eigenvalue problem, Wick product, SPDEs, finite element, Wiener-Ito chaos expansion

Procedia PDF Downloads 324
47 The Study of Sintered Wick Structure of Heat Pipes with Excellent Heat Transfer Capabilities

Authors: Im-Nam Jang, Yong-Sik Ahn

Abstract:

In this study sintered wick was formed in a heat pipe through the process of sintering a mixture of copper powder with particle sizes of 100μm and 200μm, mixed with a pore-forming agent. The heat pipe's thermal resistance, which affects its heat transfer efficiency, is determined during manufacturing according to powder type, thickness of the sintered wick, and filling rate of the working fluid. Heat transfer efficiency was then tested at various inclination angles (0°, 45°, 90°) to evaluate the performance of heat pipes. Regardless of the filling amount and test angle, the 200μm copper powder type exhibited superior heat transfer efficiency compared to the 100μm type. After analyzing heat transfer performance at various filling rates between 20% and 50%, it was determined that the heat pipe's optimal heat transfer capability occurred at a working fluid filling rate of 30%. The width of the wick was directly related to the heat transfer performance.

Keywords: heat pipe, heat transfer performance, effective pore size, capillary force, sintered wick

Procedia PDF Downloads 20
46 Optimization of Copper-Water Negative Inclination Heat Pipe with Internal Composite Wick Structure

Authors: I. Brandys, M. Levy, K. Harush, Y. Haim, M. Korngold

Abstract:

Theoretical optimization of a copper-water negative inclination heat pipe with internal composite wick structure has been performed, regarding a new introduced parameter: the ratio between the coarse mesh wraps and the fine mesh wraps of the composite wick. Since in many cases, the design of a heat pipe matches specific thermal requirements and physical limitations, this work demonstrates the optimization of a 1 m length, 8 mm internal diameter heat pipe without an adiabatic section, at a negative inclination angle of -10º. The optimization is based on a new introduced parameter, LR: the ratio between the coarse mesh wraps and the fine mesh wraps.

Keywords: heat pipe, inclination, optimization, ratio

Procedia PDF Downloads 298
45 Investigation of Cascade Loop Heat Pipes

Authors: Nandy Putra, Atrialdipa Duanovsah, Kristofer Haliansyah

Abstract:

The aim of this research is to design a LHP with low thermal resistance and low condenser temperature. A Self-designed cascade LHP was tested by using biomaterial, sintered copper powder, and aluminum screen mesh as the wick. Using pure water as the working fluid for the first level of the LHP and 96% alcohol as the working fluid for the second level of LHP, the experiments were run with 10W, 20W, and 30W heat input. Experimental result shows that the usage of biomaterial as wick could reduce more temperature at evaporator than by using sintered copper powder and screen mesh up to 22.63% and 37.41% respectively. The lowest thermal resistance occurred during the usage of biomaterial as wick of heat pipe, which is 2.06 oC/W. The usage of cascade system could be applied to LHP to reduce the temperature at condenser and reduced thermal resistance up to 17.6%.

Keywords: biomaterial, cascade loop heat pipe, screen mesh, sintered Cu

Procedia PDF Downloads 233
44 Solving SPDEs by Least Squares Method

Authors: Hassan Manouzi

Abstract:

We present in this paper a useful strategy to solve stochastic partial differential equations (SPDEs) involving stochastic coefficients. Using the Wick-product of higher order and the Wiener-Itˆo chaos expansion, the SPDEs is reformulated as a large system of deterministic partial differential equations. To reduce the computational complexity of this system, we shall use a decomposition-coordination method. To obtain the chaos coefficients in the corresponding deterministic equations, we use a least square formulation. Once this approximation is performed, the statistics of the numerical solution can be easily evaluated.

Keywords: least squares, wick product, SPDEs, finite element, wiener chaos expansion, gradient method

Procedia PDF Downloads 385
43 Solar Still Absorber Plate Modification and Exergy Analysis

Authors: Dudul Das, Pankaj Kalita, Sangeeta Borah

Abstract:

Freshwater availability in the world is as low as 1% of total water available and in many geographical locations dissolved fluoride and arsenic are serious problem. In India availability of freshwater will be stressed by 2025, so the availability saline water from sea is a hope for the people of Indian sub-continent, but saline water is not drinkable it need to be processed, which again require a huge amount of energy. So the most easy and handy option in such situation for all those problems is solar still, this investigation presents various scopes for improvement of its efficiency. Experiments showed that by increasing the absorber plate area through better design can increase the distillate output by two fold and by using jute wicks in the modified absorber plate increases the output up to three times that of conventional solar still available in the Department of Energy, Tezpur University. The experiment is carried out at constant water depth of 8.5 cm and glass cover inclination of 27o facing South. The exergy analysis carried out clearly resulted that with the use of jute wick and baffle plated basin the efficiency achieved more than the simple baffle plated basin. The Instantaneous exergy without jute wick ranges from 2.5% to 4.5% while using jute it ranges from 1.5% to 5.15%.

Keywords: fluoride, absorber plate, jute wick, instantaneous exergy

Procedia PDF Downloads 431
42 Theoretical Analysis and Design Consideration of Screened Heat Pipes for Low-Medium Concentration Solar Receivers

Authors: Davoud Jafari, Paolo Di Marco, Alessandro Franco, Sauro Filippeschi

Abstract:

This paper summarizes the results of an investigation into the heat pipe heat transfer for solar collector applications. The study aims to show the feasibility of a concentrating solar collector, which is coupled with a heat pipe. Particular emphasis is placed on the capillary and boiling limits in capillary porous structures, with different mesh numbers and wick thicknesses. A mathematical model of a cylindrical heat pipe is applied to study its behaviour when it is exposed to higher heat input at the evaporator. The steady state analytical model includes two-dimensional heat conduction in the HP’s wall, the liquid flow in the wick and vapor hydrodynamics. A sensitivity analysis was conducted by considering different design criteria and working conditions. Different wicks (mesh 50, 100, 150, 200, 250, and, 300), different porosities (0.5, 0.6, 0.7, 0.8, and 0.9) with different wick thicknesses (0.25, 0.5, 1, 1.5, and 2 mm) are analyzed with water as a working fluid. Results show that it is possible to improve heat transfer capability (HTC) of a HP by selecting the appropriate wick thickness, the effective pore radius, and lengths for a given HP configuration, and there exist optimal design criteria (optimal thick, evaporator adiabatic and condenser sections). It is shown that the boiling and wicking limits are connected and occurs in dependence on each other. As different parts of the HP external surface collect different fractions of the total incoming insolation, the analysis of non-uniform heat flux distribution indicates that peak heat flux is not affecting parameter. The parametric investigations are aimed to determine working limits and thermal performance of HP for medium temperature SC application.

Keywords: screened heat pipes, analytical model, boiling and capillary limits, concentrating collector

Procedia PDF Downloads 526
41 MHD Boundary Layer Flow of a Nanofluid Past a Wedge Shaped Wick in Heat Pipe

Authors: Ziya Uddin

Abstract:

This paper deals with the theoretical and numerical investigation of magneto-hydrodynamic boundary layer flow of a nano fluid past a wedge shaped wick in heat pipe used for the cooling of electronic components and different type of machines. To incorporate the effect of nanoparticle diameter, concentration of nanoparticles in the pure fluid, nano thermal layer formed around the nanoparticle and Brownian motion of nano particles etc., appropriate models are used for the effective thermal and physical properties of nano fluids. To model the rotation of nano particles inside the base fluid, microfluidics theory is used. In this investigation ethylene glycol (EG) based nanofluids, are taken into account. The non-linear equations governing the flow and heat transfer are solved by using a very effective particle swarm optimization technique along with Runge-Kutta method. The values of heat transfer coefficient are found for different parameters involved in the formulation viz. nanoparticle concentration, nanoparticle size, magnetic field and wedge angle etc. It is found that the wedge angle, presence of magnetic field, nanoparticle size and nanoparticle concentration etc. have prominent effects on fluid flow and heat transfer characteristics for the considered configuration.

Keywords: nanofluids, wedge shaped wick, heat pipe, numerical modeling, particle swarm optimization, nanofluid applications, Heat transfer

Procedia PDF Downloads 355
40 Promoting Self-Esteem and Social Integration in Secondary German Schools: An Evaluation Study

Authors: Susanne Manes, Anni Glaeser, Katharina Wick, Bernhard Strauss, Uwe Berger

Abstract:

Introduction: Over the last decades growing rates of mental health concerns among children and adolescents have been observed. At the same time, physical well-being of children and adolescents becomes increasingly impaired as well. Schools play an important role in preventing mental and physical disorders and in promoting well-being. Self-esteem, as well as social integration, are vital influence factors for mental and physical well-being. The purpose of this study was to develop and evaluate the program 'VorteilJena' for secondary schools in Germany focusing on self-esteem and social integration to improve mental and physical well-being. Method: The school-based health promotion program was designed for students in 5th grade and higher. It consists of several short pedagogical exercises instructed by a teacher and were integrated into the regular class over the course of ten weeks. The exercises focused on fostering social integration using either tasks improving team spirit or exercises that increase tolerance and sense of belonging. Other exercises focused on strengthening the self-esteem of the students. Additionally, the program included a poster exhibition titled 'Belonging' which was put up in the school buildings. The exhibition comprised ten posters which addressed relevant risk factors and resources related to social integration and self-esteem. The study was a randomized controlled sequential study with a pre and post measurement conducted in ten German schools. A total of 1642 students (44% male) were recruited. Their age ranged from 9 to 21 years (M=12.93 years; SD= 2.11). The program was conducted in classes ranging from 5th to 12th grade. Results: The program improved wellbeing, self-esteem and social integration of the involved students compared to the control group. Differential effects depending on implementation rates or age of the students will be analyzed. Moreover, implications for future school-based health promotion programs targeting self-esteem and social integration will be discussed. Conclusion: Social integration considerably influences self-esteem and well-being of students and can be targeted by school-based programs including short and modest exercises. Since a sufficient implementation of health promotion programs is essential, the present program due to its practicability represents a good opportunity to install health promotion focusing on social integration in schools.

Keywords: social integration, well-being, health promotion in schools, self-esteem

Procedia PDF Downloads 173
39 Physics of the Riemann Zeros: The Low Bound for the Zeta Derivative via Quantum Field Theory

Authors: Andrey Egorov

Abstract:

A product of the specific Lagrangian and the entropy factor is defined. Its positive definiteness is stated for the proper coupling constant. The passage from statistical mechanics to quantum field theory is performed by Wick rotation. The Green function (a convolution of the spectral amplitude and the propagator) is positive. Masses of quasiparticles are computed as residues. The role of the zeta derivative at zeta zeros is then highlighted, and the correspondent low bound is obtained.

Keywords: mass gap, positive definite kernels, quantum fields, Riemann zeta zeros

Procedia PDF Downloads 16
38 The Influence of Consumer and Brand-Oriented Capabilities on Business Performance in Young Firms: A Quantitative Causal Model Analysis

Authors: Katharina Buttenberg

Abstract:

Customer and brand-oriented capabilities have been identified as key influencing capabilities for business performance. Especially in the early years of the firm, it is crucial to develop and consciously manage these capabilities. In this paper, the results of a quantitative analysis, investigating the causal relationship between customer- and brand-oriented (marketing) capabilities and business performance will be presented. The research displays the dependencies between the constructs and will provide practical implications for young firms in the acquisition and management of these capabilities.

Keywords: brand-oriented capabilities, customer-oriented capabilities, entrepreneurship, resource-based theory, young firms

Procedia PDF Downloads 312
37 The Europeanization of Minority and Disability Rights: A Comparative View

Authors: Katharina Crepaz

Abstract:

Both minority rights and disability rights are relatively new fields for policy-making in a European context, and both are affected by the EU’s diversity mainstreaming approach, as well as by the non-discrimination legislation drafted at the European level. These processes correspond to the classic understanding of Europeanization, namely a “top-down” stream of influence from the European to the national and subnational levels. However, both minority and disability rights movements also show instances of “bottom-up” Europeanization, e.g. transnational advocacy networks and efforts to reach joint goals at the EU-level. This paper aims to provide a comparative perspective on Europeanization in both fields, pointing out similar dynamics and patterns, but also explaining in which sectors outcomes may be different and which domestic and other scope conditions may be responsible for these differences.

Keywords: europeanization, disability rights, minority rights, comparative perspective

Procedia PDF Downloads 381
36 Performance of the Hybrid Loop Heat Pipe

Authors: Nandy Putra, Imansyah Ibnu Hakim, Iwan Setyawan, Muhammad Zayd A.I

Abstract:

A two-phase cooling technology of passive system sometimes can no longer meet the cooling needs of an increasingly challenging due to the inherent limitations of the capillary pumping for example in terms of the heat flux that can lead to dry out. In this study, intended to overcome the dry out with the addition of a diaphragm, they pump to accelerate the fluid transportation from the condenser to the evaporator. Diaphragm pump installed on the bypass line. When it did not happen dry out then the hybrid loop heat pipe will be work passively using a capillary pressure of wick. Meanwhile, when necessary, hybrid loop heat pipe will be work actively, using diaphragm pump with temperature control installed on the evaporator. From the results, it can be said that the pump has been successfully overcome dry out and can distribute working fluid from the condenser to the evaporator and reduce the temperature of the evaporator from 143°C to 100°C as a temperature controlled where the pump start actively at set point 100°C.

Keywords: hybrid, heat pipe, dry out, assisted, pump

Procedia PDF Downloads 319
35 Solid Particle Erosion of Heat Treated TNB-V4 at Ambient and Elevated Temperatures

Authors: Muhammad Naveed, Richard Stechow, Sebastian Bolz, Katharina Hobusch, Sabine Weiß

Abstract:

Solid particle erosion has been identified as a critical wear phenomenon which takes place during operation of aeroengines in dusty environment. The present work discusses the erosion behavior of Ti-44.5Al-6.25Nb-0.8Mo-0.1B alloy (TNB-V4) which finds its application in low pressure gas turbines and can be used for high pressure compressors too. Prior to the erosion tests, the alloy was heat treated to improve the mechanical properties. Afterwards, specimens were eroded at impact angles of 30° and 90° at room and high temperatures (100 °C-400 °C). Volume loss and erosion behavior are studied through gravimetric analysis, whereas erosion mechanisms are characterized through scanning electron microscopy. The results indicate a clear difference in the erosion mechanism for different impact angles. The influence of the test temperature on the erosion behavior of the alloy is also discussed in the present contribution.

Keywords: solid particle erosion, gamma TiAl, TNB-V4, high temperature erosion

Procedia PDF Downloads 319
34 Performance of Flat Plate Loop Heat Pipe for Thermal Management of Lithium-Ion Battery in Electric Vehicle Application

Authors: Bambang Ariantara, Nandy Putra, Rangga Aji Pamungkas

Abstract:

The development of electric vehicle batteries has resulted in very high energy density lithium-ion batteries. However, this progress is accompanied by the risk of thermal runaway, which can result in serious accidents. Heat pipes are heat exchangers that are suitable to be applied in electric vehicle battery thermal management for their lightweight, compact size and do not require external power supply. This paper aims to examine experimentally a flat plate loop heat pipe (FPLHP) performance as a heat exchanger in the thermal management system of the lithium-ion battery for electric vehicle application. The heat generation of the battery was simulated using a cartridge heater. Stainless steel screen mesh was used as the capillary wick. Distilled water, alcohol and acetone were used as working fluids with a filling ratio of 60%. It was found that acetone gives the best performance that produces the thermal resistance of 0.22 W/°C with 50 °C evaporator temperature at heat flux load of 1.61 W/cm2.

Keywords: electric vehicle, flat-plate loop heat pipe, lithium-ion battery, thermal management system

Procedia PDF Downloads 312
33 Experimental Study on Modified Double Slope Solar Still and Modified Basin Type Double Slope Multiwick Solar Still

Authors: Piyush Pal, Rahul Dev

Abstract:

Water is essential for life and fresh water is a finite resource that is becoming scarce day by day even though it is recycled by hydrological cycle. The fresh water reserves are being polluted due to expanding irrigation, industries, urban population and its development. Contaminated water leads to several health problems. With the increasing demand of fresh water, solar distillation is an alternate solution which uses solar energy to evaporate water and then to condense it, thereby collecting distilled water within or outside the same system to use it as potable water. The structure that houses the process is known as a 'solar still'. In this paper, ‘Modified double slope solar still (MDSSS)’ & 'Modified double slope basin type multiwick solar still (MDSBMSS)' have been designed to convert saline, brackish water into drinking water. In this work two different modified solar stills are fabricated to study the performance of these solar stills. For modification of solar stills, Fibre Reinforced Plastic (FRP) and Acrylic sheets are used. The experiments in MDSBMSS and MDSSS was carried on 10 September 2015 & 5 November 2015 respectively. Performances of the stills were investigated. The amount of distillate has been found 3624 Ml/day in MDSBMSS on 10 September 2015 and 2400 Ml/day in MDSSS on 5 November 2015.

Keywords: contaminated water, conventional solar still, modified solar still, wick

Procedia PDF Downloads 394
32 Hedonistic Utilitarianism: The Strategic Use of Digital Media along the Online-Offline Continuum of Sexualised Violence

Authors: Katharina Kargel, Frederic Vobbe

Abstract:

The present study examines how offenders targeting children and adolescents strategically use digital media when committing acts of sexualised violence along the online-offline continuum. Even offenders who are previously known to their victims use digital media extensively. The choice to instrumentalise digital media in order to initiate, threaten, exploit and humiliate victims demonstrates the rationale of offenders when committing acts of digitally supported violence. Through digital media, offenders can assume the power of interpretation over their victims’ situations. The ways in which digital media is used to commit violence along the online-offline continuum are a direct manifestation of the hedonistic utilitarianism demonstrated by offenders: a disposition characterised by the weighing of pleasures (“mental states”) and intrinsic value expected from using digital media against the risk of an outcome subjectively experienced as uncomfortable. Thus, sexualised violence using digital media goes beyond the traditional understanding of sexual online grooming.

Keywords: sexualized violence, offender strategy, grooming, children and adolescents, qualitative research, methodology

Procedia PDF Downloads 182
31 Loop Heat Pipe Two-Phase Heat Transports: Guidelines for Technology Utilization

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 95
30 Intuitive Decision Making When Facing Risks

Authors: Katharina Fellnhofer

Abstract:

The more information and knowledge that technology provides, the more important are profoundly human skills like intuition, the skill of using nonconscious information. As our world becomes more complex, shaken by crises, and characterized by uncertainty, time pressure, ambiguity, and rapidly changing conditions, intuition is increasingly recognized as a key human asset. However, due to methodological limitations of sample size or time frame or a lack of real-world or cross-cultural scope, precisely how to measure intuition when facing risks on a nonconscious level remains unclear. In light of the measurement challenge related to intuition’s nonconscious nature, a technique is introduced to measure intuition via hidden images as nonconscious additional information to trigger intuition. This technique has been tested in a within-subject fully online design with 62,721 real-world investment decisions made by 657 subjects in Europe and the United States. Bayesian models highlight the technique’s potential to measure skill at using nonconscious information for conscious decision making. Over the long term, solving the mysteries of intuition and mastering its use could be of immense value in personal and organizational decision-making contexts.

Keywords: cognition, intuition, investment decisions, methodology

Procedia PDF Downloads 60
29 When the Children Touched the Paintings: New German Cinema, the Red Army Faction, and their Filmic Afterlives

Authors: Rudy Ralph Martinez

Abstract:

The 1960s provided us with some of the most iconic protest images of the late-20th century. This was the result of worldwide unrest and the proliferation of filmmaking equipment, which led to a flood of photos and films depicting war and activism. Many of these images and films played a pivotal role in shaping the ever-evolving discussions surrounding the ‘60s. However, too often, radical imagery finds itself subsumed by consumer culture, a degradation that flattens radical imagery and turns it into consumer products. With this in mind, the work that follows is an analysis of one of the little-discussed chapters of the 60s and 70s, and it is that of the New German Cinema movement and its relationship with the Rote Armee Fraktion, or Red Army Faction (RAF), an armed Marxist-Leninist group founded in West Germany in 1970. The RAF arose out of a milieu which included student activists protesting Western military involvement in the Vietnam War, civil rights activists, and third world guerillas. The actions undertaken by the group throughout their first decade in existence, including bombings, and assassinations, would create West Germany’s most dire political crisis since the Nazi era, culminating in a crisis of legitimation remembered as the German Autumn, which saw the suicides of several of the militants and the assassination of SS officer-cum-prominent industrialist, Hans Martin-Schleyer. Throughout the 1970s, young filmmakers associated with the New German Cinema sought to analyze the political situation as it was unfolding, their films contributing to the public discourse in concomitance with the government and the media. Four notable examples of these films are Volker Schlöndorff and Margarethe von Trotta’sDie Verlorene Ehre der Katharina Blum oder: Wie Gewaltentstehen und wohinsieführenkann (The Lost Honour of Katharina Blum, or: How Violence Develops and Where it Can Lead) (1975), a dark drama about the media’s role in forming public opinion, Deutschland im Herbst(Germany in Autumn) (1977), an experimental collective work released mere months after the German Autumn, Rainer Werner Fassbinder’s Die Dritte Generation (The Third Generation) (1979), a satire about an inept cell of radical militants, and Die bleierne Zeit (The Leaden Time, alt. title: Marianne and Juliane) (1981), an intimate portrayal about two sisters whose activism leads them down disparate paths. The filmmakers of the New German Cinema refused to underline their films with the Manichaean claims respectively espoused by the RAF and the government. These complex portrayals found offspring in films such as Christian Petzold’s Die innere Sicherheit(The State I Am In) (2000), a portrait of a family on the run after the reunification of Germany but were countered by glossy high-budget portrayals such as Uli Edel’s Der Baader-Meinhof Komplex(The Baader-Meinhof Complex) (2008). In focusing on the aesthetic structure of these films in relation to the political atmosphere of the late-60s and 70s West Germany, I hope to shed light on questions concerning spectatorship, surveillance, the role of journalism, and how politics disrupts personal relationships, and the kinship between artists and so-called terrorists.

Keywords: new german cinema, film history, red army faction, german cinema

Procedia PDF Downloads 69
28 Development of Multilayer Capillary Copper Wick Structure using Microsecond CO₂ Pulsed Laser

Authors: Talha Khan, Surendhar Kumaran, Rajeev Nair

Abstract:

The development of economical, efficient, and reliable next-generation thermal and water management systems to provide efficient cooling and water management technologies is being pursued application in compact and lightweight spacecraft. The elimination of liquid-vapor phase change-based thermal and water management systems is being done due to issues with the reliability and robustness of this technology. To achieve the motive of implementing the principle of using an innovative evaporator and condenser design utilizing bimodal wicks manufactured using a microsecond pulsed CO₂ laser has been proposed in this study. Cylin drical, multilayered capillary copper wicks with a substrate diameter of 39 mm are additively manufactured using a pulsed laser. The copper particles used for layer-by-layer addition on the substrate measure in a diameter range of 225 to 450 micrometers. The primary objective is to develop a novel, high-quality, fast turnaround, laser-based additive manufacturing process that will eliminate the current technical challenges involved with the traditional manufacturing processes for nano/micro-sized powders, like particle agglomeration. Raster-scanned, pulsed-laser sintering process has been developed to manufacture 3D wicks with controlled porosity and permeability.

Keywords: liquid-vapor phase change, bimodal wicks, multilayered, capillary, raster-scanned, porosity, permeability

Procedia PDF Downloads 160
27 Innovative Ideas through Collaboration with Potential Users

Authors: Martin Hewing, Katharina Hölzle

Abstract:

Organizations increasingly use environmental stimuli and ideas from users within participatory innovation processes in order to tap new sources of knowledge. The research presented in this article focuses on users who shape the distant edges of markets and currently are not using products and services from a domain– so called potential users. Those users at the peripheries are perceived to contribute more novel information, by which they better reflect shifts in needs and behavior than current users in the core market. Their contributions in collaborative and creative problem-solving processes and how they generate ideas for discontinuous innovations are of particular interest. With an experimental design, we compare ideas from potential and current users and analyze the effects of cognitive distance in collaboration and the utilization of explicit and tacit knowledge. We find potential users to generate more original ideas, particularly when they collaborate with someone experienced within the domain. Their ideas are most obviously characterized by an increased level of surprise and unusualness compared to dominant designs, which is rooted in contexts and does not require technological leaps. Collaboration with potential users can therefore result in new ways to leverage technological competences. Furthermore, the cross-fertilization arising from cognitive distance between a potential and a current user is asymmetric due to differences in the nature of their utilized knowledge and personal objectives. This paper discusses implications for innovation research and the management of early innovation processes.

Keywords: user collaboration, co-creation, discontinuous innovation, innovation research

Procedia PDF Downloads 476
26 Flexible Work Arrangements for Managers-Gender Diversity and Organizational Development in German Firms

Authors: Marc Gärtner, Monika Huesmann, Katharina Schiederig

Abstract:

While workplace flexibility provides opportunities to better balance work and family care, careers in management are still predominantly based on physical presence, blurred boundaries and a culture of availability at the workplace. Thus, carers (mostly women) still experience disadvantages and stalled careers. In a multi-case study, funded by the German Federal Ministry of Education and Research, success factors and barriers of flexible work arrangements in five big organizations, including three of the largest German companies, have been identified. Using qualitative interview methods, the working models of 10 female and male users of flexible work arrangements like part time, home office and job sharing have been studied. The study group applied a 360-degree approach with focus groups, covering the users’ themselves, their superiors, colleagues and staff as well as in-house human resource managers. The group interviews reveal that success of flexible models is mainly built on three factors: (a) the inclusiveness of the organizational culture, (b) the commitment of leaders and especially the supervisors, and (c) the fitting of the model and the user(s). Flexibilization of time and space can indeed contribute to a better work-life balance. This is, however, not a necessary outcome, as the interviews suggest, but depends on the right implementation of the right model in the particular work environment. Beyond the actual study results, the presentation will also assess the methodological approach.

Keywords: flexible work, leadership, organizational culture, work-life balance

Procedia PDF Downloads 326
25 ADCOR © Muscle Damage Rapid Detection Test Based on Skeletal Troponin I Immunochromatography Reaction

Authors: Muhammad Solikhudin Nafi, Wahyu Afif Mufida, Mita Erna Wati, Fitri Setyani Rokim, M. Al-Rizqi Dharma Fauzi

Abstract:

High dose activity without any pre-exercise will impact Delayed Onset Muscle Soreness (DOMS). DOMS known as delayed pain post-exercise and induce skeletal injury which will decrease athletes’ performances. From now on, post-exercise muscle damage can be detected by measuring skeletal troponin I (sTnI) concentration in serum using ELISA but this method needs more time and cost. To prevent decreased athletes performances, screening need to be done rapidly. We want to introduce our new prototype to detect DOMS acutely. Rapid detection tests are based on immunological reaction between skeletal troponin I antibodies and sTnI in human serum or whole blood. Chemical methods that are used in the manufacture of diagnostic test is lateral flow immunoassay. The material used is rat monoclonal antibody sTnI, colloidal gold, anti-mouse IgG, nitrocellulose membrane, conjugate pad, sample pad, wick and backing card. The procedure are made conjugate (colloidal gold and mAb sTnI) and insert into the conjugate pad, gives spray sTnI mAb and anti-mouse IgG into nitrocellulose membrane, and assemble RDT. RDT had been evaluated by measuring the sensitivity of positive human serum (n = 30) and negative human serum (n = 30). Overall sensitivity value was 93% and specificity value was 90%. ADCOR as the first rapid detection test qualitatively showed antigen-antibody reaction and showed good overall performances for screening of muscle damage. Furthermore, these finding still need more improvements to get best results.

Keywords: DOMS, sTnI, rapid detection test, ELISA

Procedia PDF Downloads 484
24 Sustainability in Luxury Hotels: Between a Necessary Evolution and a Way of Differentiation

Authors: Katharina Schuck

Abstract:

For a long time, luxury hotels devoted little effort to sustainability, and also scientists were fairly attracted to this subject. While some luxury hotels are now increasingly showing engagement in sustainability, the extent of their commitment varies greatly, which makes the whole industry quite intransparent when it comes to sustainable practices. In general, each hotel companyand each individual hotel can decide for themselves to what extent they commit to sustainability as long as there are no legally prescribed minimum requirements in the respective countries. Despite pleading and compelling calls from industry experts and representatives of relevant sustainability institutions, this is still reality – although climate change and environmental disasters as well as poor treatment of workers and the local population are also issues in progressive and hotel-dense European cities. This paper therefore deals with the question which sustainability activities (environmental and social) have been established by European luxury hotels so far and to what extent these activities are rather a way to differentiate in the market or are simply evaluated as part of a necessary adaptation of the luxury hotel industry. For this purpose, interviews were conducted with both industry experts and hotel representatives in order to obtain a diverse picture of the current status. The studyrevealed that a clear agenda is missing so far, which takes luxury hotels by the handand supports them in the process towards more sustainable hotel management. While a large part of the luxury hotels addressed have already established initiatives and activities regarding sustainability, they are extremely diverse, and range from recyclable toiletries use to comprehensive concepts for energy generation. The study's findings provide insights for both practitioners who seek to implement sustainability in a luxury hotel setting as well as offer an extension of the existing research base on sustainability in hospitality.

Keywords: luxury hospitality, qualitative research methods, sustainability, sustainable hotels

Procedia PDF Downloads 84
23 Willingness to Adopt "Green Steel" Products: A Case Study from the Automotive Sector

Authors: Hasan Muslemani, Jeffrey Wilson, Xi Liang, Francisco Ascui, Katharina Kaesehage

Abstract:

This paper aims to examine consumer behaviour towards, and the willingness to adopt, green steel use in the automotive sector, in order to identify potential barriers and opportunities for its widespread adoption. Semi-structured interviews were held with experts from global, regional and country-specific industry associations and automakers. The analysis shows there is a new shift towards lifecycle thinking in the sector, although these efforts have been voluntary and driven by customer and employee pressures rather than regulation. The paper further appraises possible demand for green steel within different vehicle types (based on size and powertrain), and shows that manufacturers of electric heavy-duty vehicles are most likely to adopt green steel in the first instance, given the amount of incorporated steel in the vehicles and the fact that lifecycle emissions lie predominantly in their manufacturing phase. A case for green advanced higher-strength steels (AHSS) can also be made in light-duty passenger vehicles, which may mitigate competition from light-weight alternative materials in terms of cost and greenness (depending on source and utilisation zones). This work builds on a wide sustainability-related literature in the automotive sector and highlights areas in need of urgent action if the sector as a whole were to meet its Paris Agreement climate targets, in particular a need to revisit current CO2 performance regulations to include Scope 1 and Scope 2 emissions, engage in educational green marketing campaigns, and explore innovative market-based mechanisms to bridge the gap between relatively-low carbon abatement costs of steelmaking and high abatement costs of vehicle manufacturing.

Keywords: Green steel, Consumer behaviour, Automotive industry, Environmental sustainability

Procedia PDF Downloads 134
22 Distraction from Pain: An fMRI Study on the Role of Age-Related Changes in Executive Functions

Authors: Katharina M. Rischer, Angelika Dierolf, Ana M. Gonzalez-Roldan, Pedro Montoya, Fernand Anton, Marian van der Meulen

Abstract:

Even though age has been associated with increased and prolonged episodes of pain, little is known about potential age-related changes in the ˈtop-downˈ modulation of pain, such as cognitive distraction from pain. The analgesic effects of distraction result from competition for attentional resources in the prefrontal cortex (PFC), a region that is also involved in executive functions. Given that the PFC shows pronounced age-related atrophy, distraction may be less effective in reducing pain in older compared to younger adults. The aim of this study was to investigate the influence of aging on task-related analgesia and the underpinning neural mechanisms, with a focus on the role of executive functions in distraction from pain. In a first session, 64 participants (32 young adults: 26.69 ± 4.14 years; 32 older adults: 68.28 ± 7.00 years) completed a battery of neuropsychological tests. In a second session, participants underwent a pain distraction paradigm, while fMRI images were acquired. In this paradigm, participants completed a low (0-back) and a high (2-back) load condition of a working memory task while receiving either warm or painful thermal stimuli to their lower arm. To control for age-related differences in sensitivity to pain and perceived task difficulty, stimulus intensity, and task speed were individually calibrated. Results indicate that both age groups showed significantly reduced activity in a network of regions involved in pain processing when completing the high load distraction task; however, young adults showed a larger neural distraction effect in different parts of the insula and the thalamus. Moreover, better executive functions, in particular inhibitory control abilities, were associated with a larger behavioral and neural distraction effect. These findings clearly demonstrate that top-down control of pain is affected in older age, and could explain the higher vulnerability for older adults to develop chronic pain. Moreover, our findings suggest that the assessment of executive functions may be a useful tool for predicting the efficacy of cognitive pain modulation strategies in older adults.

Keywords: executive functions, cognitive pain modulation, fMRI, PFC

Procedia PDF Downloads 107
21 Evaluation of Different Anticoagulant Effects on Flow Properties of Human Blood Using Falling Needle Rheometer

Authors: Hiroki Tsuneda, Takamasa Suzuki, Hideki Yamamoto, Kimito Kawamura, Eiji Tamura, Katharina Wochner, Roberto Plasenzotti

Abstract:

Flow property of human blood is one of the important factors on the prevention of the circulatory condition such as a high blood pressure, a diabetes mellitus, and a cardiac infarction. However, the measurement of flow property of human blood, especially blood viscosity, is not so easy, because of their coagulation or aggregation behaviors after taking a sample from blood vessel. In the experiment, some kinds of anticoagulant were added into the human blood to avoid its solidification. Anticoagulant used in the blood test has been chosen for each purpose of blood test, for anticoagulant effect on blood is different mechanism for each. So that, there is a problem that the evaluation of measured blood property with different anticoagulant is so difficult. Therefore, it is so important to make clear the difference of anticoagulant effect on the blood property. In the previous work, a compact-size falling needle rheometer (FNR) has been developed in order to measure the flow property of human blood such as a flow curve, an apparent viscosity. It was found that FNR system can apply to a rheometer or a viscometry for various experimental conditions for not only human blood but also mammalians blood. In this study, the measurements of human blood viscosity with different anticoagulant (EDTA and Heparin) were carried out using newly developed FNR system. The effect of anticoagulant on blood viscosity was also tested by using the standard liquid for each. The accuracy on the viscometry was also tested by using the standard liquid for calibrating materials (JS-10, JS-20) and observed data have satisfactory agreement with reference data around 1.0% at 310K. The flow curve of six males and females with different anticoagulant were measured using FNR. In this experiment, EDTA and Heparin were chosen as anticoagulant for blood. Heparin can inhibit the coagulation of human blood by activating the body of anti-thrombin. To examine the effect of human blood viscosity on anticoagulant, flow curve was measured at high shear rate (>350s-1), and apparent viscosity of each person were determined with different anticoagulant. The apparent viscosity of human blood with heparin was 2%-9% higher than that with EDTA. However, the difference of blood viscosity for two anticoagulants for same blood was different for each. Further discussion, we need the consideration of effect on other physical property, such as cellular component and plasma component.

Keywords: falling-needle rheometer, human blood, viscosity, anticoagulant

Procedia PDF Downloads 412
20 Entrepreneurship Education Revised: Merging a Theory-Based and Action-Based Framework for Entrepreneurial Narratives' Impact as an Awareness-Raising Teaching Tool

Authors: Katharina Fellnhofer, Kaisu Puumalainen

Abstract:

Despite the current worldwide increasing interest in entrepreneurship education (EE), little attention has been paid to innovative web-based ways such as the narrative approach by telling individual stories of entrepreneurs via multimedia for demonstrating the impact on individuals towards entrepreneurship. In addition, this research discipline is faced with no consensus regarding its effective content of teaching materials and tools. Therefore, a qualitative hypothesis-generating research contribution is required to aim at drawing new insights from published works in the EE field of research to serve for future research related to multimedia entrepreneurial narratives. Based on this background, our effort will focus on finding support regarding following introductory statement: Multimedia success and failure stories of real entrepreneurs show potential to change perceptions towards entrepreneurship in a positive way. The proposed qualitative conceptual paper will introduce the underlying background for this research framework. Therefore, as a qualitative hypothesis-generating research contribution it aims at drawing new insights from published works in the EE field of research related to entrepreneurial narratives to serve for future research. With the means of the triangulation of multiple theories, we will utilize the foundation for multimedia-based entrepreneurial narratives applying a learning-through-multimedia-real-entrepreneurial-narratives pedagogical tool to facilitate entrepreneurship. Our effort will help to demystify how value-oriented entrepreneurs telling their stories multimedia can simultaneously enhance EE. Therefore, the paper will build new-fangled bridges between well-cited theoretical constructs to build a robust research framework. Overall, the intended contribution seeks to emphasize future research of currently under-researched issues in the EE sphere, which are considered to be essential not only to academia, as well as to business and society having future jobs-providing growth-oriented entrepreneurs in mind. The Authors would like to thank the Austrian Science Fund FWF: [J3740 – G27].

Keywords: entrepreneurship education, entrepreneurial attitudes and perceptions, entrepreneurial intention, entrepreneurial narratives

Procedia PDF Downloads 222