Search results for: type of foundation

Authors: Carine Muster, Prina Howald Erika

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Today's ice rinks are important energy consumers for the production and maintenance of ice. At the same time, users demand that the other rooms should be tempered or heated. The building complex must equally provide cooled and heated zones, which does not translate as carbon-zero ice rinks. The study provides an analysis of how the civil engineering sector can significantly impact minimizing greenhouse gas emissions and optimizing synergies across an entire ice rink complex. The analysis focused on three distinct aspects: the layout, including the volumetric layout of the premises present in an ice rink; the materials chosen that can potentially use the most ecological structural approach; and the construction methods based on innovative solutions to reduce carbon footprint. The first aspect shows that the organization of the interior volumes and defining the shape of the rink play a significant role. Its layout makes the use and operation of the premises as efficient as possible, thanks to the differentiation between heated and cooled volumes while optimising heat loss between the different rooms. The sprayed concrete method, which is still little known, proves that it is possible to achieve the strength of traditional concrete for the structural aspect of the load-bearing and non-load-bearing walls of the ice rink by using materials excavated from the construction site and providing a more ecological and sustainable solution. The installation of an empty sanitary space underneath the ice floor, making it independent of the rest of the structure, provides a natural insulating layer, preventing the transfer of cold to the rest of the structure and reducing energy losses. The addition of active pipes as part of the foundation of the ice floor, coupled with a suitable system, gives warmth in the winter and storage in the summer; this is all possible thanks to the natural heat in the ground. In conclusion, this study provides construction recommendations for future ice rinks with a significantly reduced energy demand, using some simple preliminary design concepts. By optimizing the layout, materials, and construction methods of ice rinks, the civil engineering sector can play a key role in reducing greenhouse gas emissions and promoting sustainability.

Keywords: climate change, energy optimization, green building, sustainability

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Authors: E. Obreque-Slier, V. Contreras-Cortez, R. López-Solís

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Astringency is a drying, roughing, and sometimes puckering sensation that is experienced on the various oral surfaces during or immediately after tasting foods. This sensation has been closely related to the interaction and precipitation between salivary proteins and polyphenols, specifically flavanols or proanthocyanidins. In addition, the type and concentration of proanthocyanidin influences significantly the intensity of the astringency and consequently the protein/proanthocyanidin interaction. However, most of the studies are based on the interaction between saliva and highly complex polyphenols, without considering the effect of monomeric proanthoancyanidins present in different foods. The aim of this study was to evaluate the effect of different monomeric proanthocyanidins on the diffusion and precipitation of salivary proteins. Thus, solutions of catechin, epicatechin, epigallocatechin and gallocatechin (0, 2.0, 4.0, 6.0, 8.0 and 10 mg/mL) were mixed with human saliva (1: 1 v/v). After incubation for 5 min at room temperature, 15 µL aliquots of each mix were dotted on a cellulose membrane and allowed to dry spontaneously at room temperature. The membrane was fixed, rinsed and stained for proteins with Coomassie blue. After exhaustive washing in 7% acetic acid, the membrane was rinsed once in distilled water and dried under a heat lamp. Both diffusion area and stain intensity of the protein spots were semiqualitative estimates for protein-tannin interaction (diffusion test). The rest of the whole saliva-phenol solution mixtures of the diffusion assay were centrifuged, and 15-μL aliquots from each of the supernatants were dotted on a cellulose membrane. The membrane was processed for protein staining as indicated above. The blue-stained area of protein distribution corresponding to each of the extract dilution-saliva mixtures was quantified by Image J 1.45 software. Each of the assays was performed at least three times. Initially, salivary proteins display a biphasic distribution on cellulose membranes, that is, when aliquots of saliva are placed on absorbing cellulose membranes, and free diffusion of saliva is allowed to occur, a non-diffusible protein fraction becomes surrounded by highly diffusible salivary proteins. In effect, once diffusion has ended, a protein-binding dye shows an intense blue-stained roughly circular area close to the spotting site (non-diffusible fraction) (NDF) which becomes surrounded by a weaker blue-stained outer band (diffusible fraction) (DF). Likewise, the diffusion test showed that epicatechin caused the complete disappearance of DF from saliva with 2 mg/mL. Also, epigallocatechin and gallocatechin caused a similar effect with 4 mg/mL, while catechin generated the same effect at 8 mg/mL. In the precipitation test, the use of epicatechin and gallocatechin generated evident precipitates at the bottom of the Eppendorf tubes. In summary, the flavanol type differentially affects the diffusion and precipitation of saliva, which would affect the sensation of astringency perceived by consumers.

Keywords: astringency, polyphenols, tannins, tannin-protein interaction

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Authors: Zeenat Rupawalla, Nicole Robinson, Susanne Schmidt, Sijie Li, Selina Carruthers, Elodie Buisset, John Roles, Ben Hankamer, Juliane Wolf

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Agriculture has radically changed the global biogeochemical cycle of nitrogen (N). Fossil fuel-enabled synthetic N-fertiliser is a foundation of modern agriculture but applied to soil crops only use about half of it. To address N-pollution from cropping and the large carbon and energy footprint of N-fertiliser synthesis, new technologies delivering enhanced energy efficiency, decarbonisation, and a circular nutrient economy are needed. We characterised algae fertiliser (AF) as an alternative to synthetic N-fertiliser (SF) using empirical and modelling approaches. We cultivated microalgae in nutrient solution and modelled up-scaled production in nutrient-rich wastewater. Over four weeks, AF released 63.5% of N as ammonium and nitrate, and 25% of phosphorous (P) as phosphate to the growth substrate, while SF released 100% N and 20% P. To maximise crop N-use and minimise N-leaching, we explored AF and SF dose-response-curves with spinach in glasshouse conditions. AF-grown spinach produced 36% less biomass than SF-grown plants due to AF’s slower and linear N-release, while SF resulted in 5-times higher N-leaching loss than AF. Optimised blends of AF and SF boosted crop yield and minimised N-loss due to greater synchrony of N-release and crop uptake. Additional benefits of AF included greener leaves, lower leaf nitrate concentration, and higher microbial diversity and water holding capacity in the growth substrate. Life-cycle-analysis showed that replacing the most effective SF dosage with AF lowered the carbon footprint of fertiliser production from 2.02 g CO₂ (C-producing) to -4.62 g CO₂ (C-sequestering), with a further 12% reduction when AF is produced on wastewater. Embodied energy was lowest for AF-SF blends and could be reduced by 32% when cultivating algae on wastewater. We conclude that (i) microalgae offer a sustainable alternative to synthetic N-fertiliser in spinach production and potentially other crop systems, and (ii) microalgae biofertilisers support the circular nutrient economy and several sustainable development goals.

Keywords: bioeconomy, decarbonisation, energy footprint, microalgae

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Authors: Y. Lasbet, A. L. Boukhalkhal, K. Loubar

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The study of mixed convection is, usually, focused on the straight channels in which the onset of the mixed convection is well defined as function of the ratio between Grashof number and Reynolds number, Gr/Re. This is not the case for a complex channel wherein the mixed convection is not sufficiently examined in the literature. Our paper focuses on the study of the mixed convection in a complex geometry in which our main contribution reveals that the critical value of the ratio Gr/Re for the onset of the mixed convection increases highly in the type of geometry contrary to the straight channel. Furthermore, the accentuated secondary flow in this geometry prevents the thermal stratification in the flow and consequently the buoyancy driven becomes negligible. To perform these objectives, a numerical study in complex geometry for several values of the ratio Gr/Re with prescribed wall heat flux (H2), was realized by using the CFD code.

Keywords: complex geometry, heat transfer, laminar flow, mixed convection, Nusselt number

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Authors: Gabriela T. Nakashima, Ana Larissa S. Hansted, Gabriela B. Belini, Carlos R. Sette Jr, Hiroyuki Yamamoto, Fabio M. Yamaji

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The aim of this study was to determine the interference from contaminants in the characterization of sugarcane straw. The sugarcane straw was collected after the harvest and taken to the drying oven, and then it was crushed in the mill type Willey. Analyzes of ash contents and Klason lignin were done in triplicate and high heating value (HHV) in duplicate, according to ASTM standard. The results obtained for the sugarcane straw were 5.29% for ash content, 29.87% for Klason lignin and 17.67 MJ.kg-1 for HHV. Also, the material was analyzed by scanning electron microscope (SEM). The presence of contaminants was observed, such as silica. The high amount of contaminants in the samples may impact the results of analyzes, also raising its values, for example in the Klason lignin content. These contaminants can also adversely affect the quality of the biomass. Even using the standards is important to know what the purpose of the analysis and care mainly of sampling.

Keywords: biomass, bioenergy, residues, solid fuel

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Authors: Bheki R. Mngomezulu

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The present paper cogently and systematically traces the history of Umkhonto Wesizwe (MK) and identifies its important role in shaping South Africa’s post-apartheid foreign policy and international relations under black leadership. It provides the political and historical contexts within which we can interpret and better understand South Africa’s controversial ‘Quiet Diplomacy’ approach to Zimbabwe’s endemic political and economic crises, which have dragged for too long. On 16 December 1961, the African National Congress (ANC) officially launched the MK as its military wing. The main aim was to train liberation fighters outside South Africa who would return into the country to topple the apartheid regime. Subsequently, the ANC established links with various countries across Africa and the globe in order to solicit arms, financial resources and military training for its recruits into the MK. Drawing from archival research and empirical data obtained through oral interviews that were conducted with some of the former MK cadres, this paper demonstrates how the ANC forged relations with a number of countries that were like-minded in order to ensure that its dream of removing the apartheid government became a reality. The findings reveal that South Africa’s foreign policy posture and international relations after the demise of apartheid in 1994 built on these relations. As such, even former and current socialist countries that were frowned upon by the Western world became post-apartheid South Africa’s international partners. These include countries such as Cuba and China, among others. Even countries that were not recognized by the Western world as independent states received good reception in post-apartheid South Africa’s foreign policy agenda. One of these countries is Palestine. Within Africa, countries with questionable human rights records such as Nigeria and Zimbabwe were accommodated in South Africa’s foreign policy agenda after 1994. Drawing from this history, the paper concludes that it would be difficult to fully understand and appreciate South Africa’s foreign policy direction and international relations after 1994 without bringing the history and the politics of the MK into the equation. Therefore, the paper proposes that the utilitarian role of history should never be undermined in the analysis of a country’s foreign policy direction and international relations. Umkhonto Wesizwe and South Africa are used as examples to demonstrate how such a link could be drawn through archival and empirical evidence.

Keywords: African National Congress, apartheid, foreign policy, international relations

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Authors: E. Calil, L. A. Pereira

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The acquisition of orthography is a complex process, involving both lexical and grammatical questions. This learning occurs simultaneously with the domain of multiple textual aspects (e.g.: graphs, punctuation, etc.). However, most of the research on orthographic acquisition focus on this acquisition from an autonomous point of view, separated from the process of textual production. This means that their object of analysis is the production of words selected by the researcher or the requested sentences in an experimental and controlled setting. In addition, the analysis of the Spelling Problems (SP) are identified by the researcher on the sheet of paper. Considering the perspective of Textual Genetics, from an enunciative approach, this study will discuss the SPs recognized by dyads of newly literate students, while they are writing a text collaboratively. Six proposals of textual production were registered, requested by a 2nd year teacher of a Portuguese Primary School between January and March 2015. In our case study we discuss the SPs recognized by the dyad B and L (7 years old). We adopted as a methodological tool the Ramos System audiovisual record. This system allows real-time capture of the text in process and of the face-to-face dialogue between both students and their teacher, and also captures the body movements and facial expressions of the participants during textual production proposals in the classroom. In these ecological conditions of multimodal registration of collaborative writing, we could identify the emergence of SP in two dimensions: i. In the product (finished text): SP identification without recursive graphic marks (without erasures) and the identification of SPs with erasures, indicating the recognition of SP by the student; ii. In the process (text in progress): identification of comments made by students about recognized SPs. Given this, we’ve analyzed the comments on identified SPs during the text in progress. These comments characterize a type of reformulation referred to as Commented Oral Erasure (COE). The COE has two enunciative forms: Simple Comment (SC) such as ' 'X' is written with 'Y' '; or Unfolded Comment (UC), such as ' 'X' is written with 'Y' because...'. The spelling COE may also occur before or during the SP (Early Spelling Recognition - ESR) or after the SP has been entered (Later Spelling Recognition - LSR). There were 631 words entered in the 6 stories written by the B-L dyad, 145 of them containing some type of SP. During the text in progress, the students recognized orally 174 SP, 46 of which were identified in advance (ESRs) and 128 were identified later (LSPs). If we consider that the 88 erasure SPs in the product indicate some form of SP recognition, we can observe that there were twice as many SPs recognized orally. The ESR was characterized by SC when students asked their colleague or teacher how to spell a given word. The LSR presented predominantly UC, verbalizing meta-orthographic arguments, mostly made by L. These results indicate that writing in dyad is an important didactic strategy for the promotion of metalinguistic reflection, favoring the learning of spelling.

Keywords: collaborative writing, erasure, learning, metalinguistic awareness, spelling, text production

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Authors: Zuyong Chen, Jianghao Wu, Yanlai Zhang

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Flapping-wing micro aerial vehicle (FMAV) is a new type of aircraft by mimicking the flying behavior to that of small birds or insects. Comparing to the traditional fixed wing or rotor-type aircraft, FMAV only needs to control the motion of flapping wings, by changing the size and direction of lift to control the flight attitude. Therefore, its transmission system should be designed very compact. Lightweight design can effectively extend its endurance time, while engineering experience alone is difficult to simultaneously meet the requirements of FMAV for structural strength and quality. Current researches still lack the guidance of considering nonlinear factors of 3D printing material when carrying out topology optimization, especially for the tiny FMAV transmission system. The coupling of non-linear material properties and non-linear contact behaviors of FMAV transmission system is a great challenge to the reliability of the topology optimization result. In this paper, topology optimization design based on FEA solver package Altair Optistruct for the transmission system of FMAV manufactured by 3D Printing was carried out. Firstly, the isotropic constitutive behavior of the Ultraviolet (UV) Cureable Resin used to fabricate the structure of FMAV was evaluated and confirmed through tensile test. Secondly, a numerical computation model describing the mechanical behavior of FMAV transmission structure was established and verified by experiments. Then topology optimization modeling method considering non-linear factors were presented, and optimization results were verified by dynamic simulation and experiments. Finally, detail discussions of different load status and constraints were carried out to explore the leading factors affecting the optimization results. The contributions drawn from this article helpful for guiding the lightweight design of FMAV are summarizing as follow; first, a dynamic simulation modeling method used to obtain the load status is presented. Second, verification method of optimized results considering non-linear factors is introduced. Third, based on or can achieve a better weight reduction effect and improve the computational efficiency rather than taking multi-states into account. Fourth, basing on makes for improving the ability to resist bending deformation. Fifth, constraint of displacement helps to improve the structural stiffness of optimized result. Results and engineering guidance in this paper may shed lights on the structural optimization and light-weight design for future advanced FMAV.

Keywords: flapping-wing micro aerial vehicle, 3d printing, topology optimization, finite element analysis, experiment

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Authors: Anna Stepien

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The paper presents the results of research on modifications of sand-lime bricks, especially using glass additives (glass fiber and glass sand) and other additives (e.g.:basalt&barite aggregate, lithium silicate and microsilica) as well. The main goal of this paper is to answer the question ‘How to use glass additives in the sand-lime mass and get a better bricks?’ The article contains information on modification of sand-lime bricks using glass fiber, glass sand, microsilica (different structure of silica). It also presents the results of the conducted compression tests, which were focused on compressive strength, water absorption, bulk density, and their microstructure. The Scanning Electron Microscope, spectrum EDS, X-ray diffractometry and DTA analysis helped to define the microstructural changes of modified products. The interpretation of the products structure revealed the existence of diversified phases i.e.the C-S-H and tobermorite. CaO-SiO2-H2O system is the object of intensive research due to its meaning in chemistry and technologies of mineral binding materials. Because the blocks are the autoclaving materials, the temperature of hydrothermal treatment of the products is around 200°C, the pressure - 1,6-1,8 MPa and the time - up to 8hours (it means: 1h heating + 6h autoclaving + 1h cooling). The microstructure of the products consists mostly of hydrated calcium silicates with a different level of structural arrangement. The X-ray diffraction indicated that the type of used sand is an important factor in the manufacturing of sand-lime elements. Quartz sand of a high hardness is also a substrate hardly reacting with other possible modifiers, which may cause deterioration of certain physical and mechanical properties. TG and DTA curves show the changes in the weight loss of the sand-lime bricks specimen against time as well as the endo- and exothermic reactions that took place. The endothermic effect with the maximum at T=573°C is related to isomorphic transformation of quartz. This effect is not accompanied by a change of the specimen weight. The next endothermic effect with the maximum at T=730-760°C is related to the decomposition of the calcium carbonates. The bulk density of the brick it is 1,73kg/dm3, the presence of xonotlite in the microstructure and significant weight loss during DTA and TG tests (around 0,6% after 70 minutes) have been noticed. Silicate elements were assessed on the basis of their compressive property. Orthogonal compositional plan type 3k (with k=2), i.e.full two-factor experiment was applied in order to carry out the experiments both, in the compression strength test and bulk density test. Some modification (e.g.products with barite and basalt aggregate) have improved the compressive strength around 41.3 MPa and water absorption due to capillary raising have been limited to 12%. The next modification was adding glass fiber to sand-lime mass, then glass sand. The results show that the compressive strength was higher than in the case of traditional bricks, while modified bricks were lighter.

Keywords: bricks, fiber, glass, microstructure

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Authors: Changyin Zhou

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Ba constructions are a special type of constructions in Chinese. Their syntactic behaviors are closely related to their event structural properties. The existing study which treats the semantic function of Ba as causative meets difficulty in treating the discrepancy between Ba constructions and their corresponding constructions without Ba in expressing causativity. This paper holds that Ba in Ba constructions is a functional category expressing affectedness. The affectedness expressed by Ba can be positive or negative. The functional category Ba expressing negative affectedness has the semantic property of being 'expected'. The precondition of Ba construction is the boundedness of the event concerned. This paper, holding the parallelism between motion events and change-of-state events, proposes a syntactic model based on the notions of boundedness and affectedness, discusses the transformations between Ba constructions and the related resultative constructions, and derivates the various Ba constructions concerned.

Keywords: affectedness, Ba constructions, boundedness, event structure, resultative constructions

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Authors: Min-Chih Yang, Shih-Jen Feng, Bo-Tsang Li

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The concept of “Brownfield” has been developed for nearly 35 years since it was put forward in 《Comprehensive Environmental Response, Compensation, and Liability Act, CERCLA》of USA in 1980 for solving the problem of soil contamination of those old industrial lands, and later, many countries have put forward relevant policies and researches continuously. But the related concept in Taiwan, a country has developed its industry for 60 years, is still in its infancy. This leads to the slow development of Brownfield related research and policy in Taiwan. When it comes to build the foundation of Brownfield development, we have to depend on the related experience and research of other countries. They are four aspects about Brownfield: 1. Contaminated Land; 2. Derelict Land; 3. Vacant Land; 4. Previously Development Land. This study will focus on and deeply investigate the Vacant land and contaminated land. The subject of this study is Formosa Chemicals & Fibre Corporation, Changhua branch in Taiwan. It has been operating for nearly 50 years and contributing a lot to the local economy. But under the influence of the toxic waste and sewage which was drained regularly or occasionally out from the factory, the environment has been destroyed seriously. There are three factors of pollution: 1. environmental toxicants, carbon disulfide, released from producing processes and volatile gases which is hard to monitor; 2. Waste and exhaust gas leakage caused by outdated equipment; 3. the wastewater discharge has seriously damage the ecological environment of the Dadu river estuary. Because of all these bad influences, the factory has been closed nowadays and moved to other places to spare the opportunities for the contaminated lands to re-develop. So we collect information about related Brownfield management experience and policies in different countries as background information to investigate the current Taiwanese Brownfield redevelopment issues and built the environmental assessment framework for it. We hope that we can set the environmental assessment indexes for Formosa Chemicals & Fibre Corporation, Changhua branch according to the framework. By investigating the theory and environmental pollution factors, we will carry out deep analysis and expert questionnaire to set those indexes and prove a sample in Taiwan for Brownfield redevelopment and remediation in the future.

Keywords: brownfield, industrial land, redevelopment, assessment index

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Authors: Azam Salimi, Majid Delshad

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This paper presents a modified design of a sliding mode controller based on fuzzy logic for a New ZVThigh step up DC-DC Converter . Here a proportional - integral (PI)-type current mode control is employed and a sliding mode controller is designed utilizing fuzzy algorithm. Sliding mode controller guarantees robustness against all variations and fuzzy logic helps to reduce chattering phenomenon due to sliding controller, in that way efficiency increases and error, voltage and current ripples decreases. The proposed system is simulated using MATLAB / SIMULINK. This model is tested under variations of input and reference voltages and it was found that in comparison with conventional sliding mode controllers they perform better.

Keywords: switching mode power supplies, DC-DC converters, sliding mode control, robustness, fuzzy control, current mode control, non-linear behavior

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Authors: P. Hashim, M. S. Mohd Ridzwan, J. Bakar

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Collagen was isolated from chicken feet by using papain and pepsin enzymes in acetic acid solution at 4°C for 24h with a yield of 18.16% and 22.94% by dry weight, respectively. Chemical composition and characteristics of chicken feet collagen such as amino acid composition, SDS-PAGE patterns, FTIR spectra and thermal properties were evaluated. The chicken feet collagen is rich in the amino acids glycine, glutamic acid, proline and hydroxyproline. Electrophoresis pattern demonstrated two distinct α-chains (α1 and α2) and β chain, indicating that type I collagen is a major component of chicken feet collagen. The thermal stability of collagen isolated by papain and pepsin revealed stable denaturation temperatures of 48.40 and 53.35°C, respectively. The FTIR spectra of both collagens were similar with amide regions in A, B, I, II, and III. The study demonstrated that chicken feet collagen using papain isolation method is possible as commercial alternative ingredient.

Keywords: chicken feet, collagen, papain, pepsin

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Authors: Muhammad Farid, Jen Der Day

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The purpose of this study is to explore the construct of service innovation model for Small and medium-sized enterprises (SMEs) in automotive service industries. A case study of repair shop of the motorcycle at Makassar city illustrates measure innovation implementation, the degree of innovation, and identifies the type of innovation by the service innovation model for SMEs. In this paper, we interview 10 managers of SMEs and analyze their answers. We find that innovation implementation has been slowly; only producing new service innovation 0.62 unit average per year. Incremental innovation is the present option for SMEs, because they choose safer roads to improve service continuously. If want to create radical innovation, they still consider the aspect of cost, system, and readiness of human resources.

Keywords: service innovation, incremental innovation, SMEs, automotive service industries

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Authors: Kenneth Okelo, Esther Waithaka, Maureen Mweru

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Development of oral language skills is a precursor to writing and reading acquisition. Oral skill is a means of communication through which people express their desires, ideas, excitements, amusements, disappointments and exchange information. In addition, oral skills have been found to be an important tool for thinking and concept development in children. Research carried out in industrialised countries have identified some appropriate teaching strategies used to enhance acquisition of oral language skills such as repetition, substitution, explanation, contrast, exemplification and code-switching. However, these studies’ geographical locations do not reflect the diversity of the Kenyan society. In addition, studies conducted in Kenya in the past have not established why pre-primary school teachers are not using appropriate teaching strategies. The purpose of this study was to find out whether teachers’ experience, academic qualification and type of training influences their choice of teaching strategies in the development of oral language skills inside and out of the classroom in selected preschools in Kibra Sub-County, Nairobi County. In addition, this study aimed at finding out the strategies used by teachers in Kibra Sub-County to promote oral skills development among pre-primary school children. The study was guided by Holdaway’s theory of language acquisition. Descriptive survey design was employed during this study. Questionnaires and observation schedules were used to collect data. Eighty-three (83) preschool teachers were sampled using multistage sampling methods for observation. Data was analysed using SPSS version 20. The researcher carried out content analysis on the qualitative data. The main descriptive methods used were tabulation of frequencies and percentages. Chi squire test was the inferential statistic used to test the relationship between variables. The main findings of the study indicate that teaching strategies that were mostly used by pre-primary school teachers were code-switching, examples, repetition, substitution and explanation. While questions, direction, expansion of children words and contrast were the least used teaching strategies when teaching oral language skills. The study revealed that the there is a slight correlation between the type of training of teachers and the teaching strategies as most of DICECE trained teachers used more teaching strategies when teaching oral skills compared to other teachers. The findings also revealed that there was a partial significant correlation between teacher’s academic qualifications and a few teaching strategies. A similar correlation was also observed between teaching experience and a few teaching strategies. Since the strategies used by pre-primary school teachers under the study were less than half of the recommended teaching strategies to promote oral skills, the study recommends that teachers should be encouraged to use more in structural strategies to improve children’s oral language skills.

Keywords: Kenya early childhood education, Kenya education, oral language skills acquisition, teaching methods

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Authors: Punit Kumar, Niraj Kumar

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The influence of transverse surface roughness on EHL characteristics has been investigated numerically using an extensive set of full EHL line contact simulations for shear-thinning lubricants under pure sliding condition. The shear-thinning behavior of lubricant is modeled using Carreau viscosity equation along with Doolittle-Tait equation for lubricant compressibility. The surface roughness is assumed to be sinusoidal and it is present on the stationary surface. It is found that surface roughness causes sharp pressure peaks along with reduction in central and minimum film thickness. With increasing amplitude of surface roughness, the minimum film thickness decreases much more rapidly as compared to the central film thickness.

Keywords: EHL, Carreau, shear-thinning, surface roughness, amplitude, wavelength

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Authors: Li (Claudia) Chen

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With the rapid development of the global economy, the growing prevalence of customer health consciousness has arisen over the last decade. Consumers are considered more healthy lifestyles and wellness routines in their daily life, and likewise, they are inclined to invest disposable incomes in enhancing their health and wellness, beauty, and social identity. Nowadays, visiting spas has become a popular activity; particularly, millennials are increasingly prone to visiting spas. It has now become one of the major places for relaxation, rejuvenation, revitalization, and enjoyment by providing various types of spa services such as hotel and resort spas, destination spas, mineral, and thermal spring spas, medical spas, and so forth. The hotel and resort spa has been becoming increasingly popular among other spas, which is the largest number of spas and revenue over the last five years, and has now surpassed day/salon spas as the industry revenue leader. In the hotel and resort spa industry, sensory experience plays a vital role in the customer journey, and it encompasses all aspects of the sense that can affect the overall experience. Consumers use senses-sight, sound, touch, smell, and taste to gather the information that contributes to the establishment of an experience, and all senses interacting together form the foundation of sensory experiences. Sensory marketing as a marketing strategy engages consumers' senses and affects their behaviour, yet consumers are often unaware of the way senses interact with their day-to-day experiences. Indeed, it is important to understand consumer sensory experience in terms of how it influences consumer consumption behaviour. The aim of this paper is to evaluate the sensory experiences of consumers and the ways that sensory experiences shape consumer behaviour in the hotel and resort spa industry. This paper consists of in-depth interviews, focus groups, and participant-observation methods to collect data from different stakeholders. The findings reveal that multisensory experiences play vital roles in consumer spa experiences and are highly influential in consumer perception, cognition, and behaviour. Moreover, the findings also demonstrate that sensory stimuli bring positive or negative effects on consumer experience in the hotel spa industry. Ultimately, the findings also offer additional insight to managers on sensory marketing strategy to stimulate brand experience that can establish customer loyalty.

Keywords: sensory marketing, senses, consumer behaviour, multi-sensory marketing, hotel and resorts spa industry, qualitative research

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Authors: C. S. Paglia, E. Pesenti, A. Krattiger

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Commercially available methacrylate and acrylamide-based acrylic resins for injection in concrete systems have been tested with respect to the sealing performance and the rebar corrosion. Among the different resins, a methacrylate-based type of acrylic resin significantly inhibited the rebar corrosion. This was mainly caused by the relatively high pH of the resin and the resin aqueous solution. This resin also exhibited a relatively high sealing performance, in particular after exposing the resin to durability tests. The corrosion inhibition behaviour and the sealing properties after the exposition to durability tests were maintained up to one year. The other resins either promoted the corrosion of the rebar and/or exhibited relatively low sealing properties.

Keywords: acrylic resin, sealing performance, rebar corrosion, materials

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Authors: Jyun-Hao Liao, Chien-Ju Chen, Chia-Jui Yu, Meng Chyi Wu, Chia-Ching Wu

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In this letter, we reported the fabrication of InGaAs micro-photodiode sensor array with the rapid thermal diffusion (RTD) technique. The spin-on dopant source Zn was used to form the p-type region in InP layer. Through the RTD technique, the InP/InGaAs heterostructure was formed. We improved our fabrication on the p-i-n photodiode to micro size which pixel is 7.8um, and the pitch is 12.8um. The proper SiNx was deposited to form the passivation layer. The leakage current of single pixel decrease to 3.3pA at -5V, and 35fA at -10mV. The leakage current densities of each voltage are 21uA/cm² at -5V and 0.223uA/cm² at -10mV. As we focus on the wavelength from 0.9um to 1.7um, the optimized Si/Al₂O₃ bilayers are deposited to form the AR-coating.

Keywords: InGaAs, micro sensor array, p-i-n photodiode, rapid thermal diffusion, Zn diffusion

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Authors: Spira A., Marabelle A., Kientop D., Moser E., Mumm J.

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Background: Both interleukin-2 (IL-2) and interleukin-10 (IL-10) have been extensively studied for their stimulatory function on T cells and their potential to obtain sustainable tumor control in RCC, melanoma, lung, and pancreatic cancer as monotherapy, as well as combination with PD-1 blockers, radiation, and chemotherapy. While approved, IL-2 retains significant toxicity, preventing its widespread use. The significant efforts undertaken to uncouple IL-2 toxicity from its anti-tumor function have been unsuccessful, and early phase clinical safety observed with PEGylated IL-10 was not met in a blinded Phase 3 trial. Deka Biosciences has engineered a novel molecule coupling wild-type IL-2 to a high affinity variant of Epstein Barr Viral (EBV) IL-10 via a scaffold (scFv) that binds to epidermal growth factor receptors (EGFR). This patented molecule, termed DK210 (EGFR), is retained at high levels within the tumor microenvironment for days after dosing. In addition to overlapping and non-redundant anti-tumor function, IL-10 reduces IL-2 mediated cytokine release syndrome risks and inhibits IL-2 mediated T regulatory cell proliferation. Methods: DK210 (EGFR) is being evaluated in an open-label, dose-escalation (Phase 1) study with 5 (0.025-0.3 mg/kg) monotherapy dose levels and (expansion cohorts) in combination with PD-1 blockers, or radiation or chemotherapy in patients with advanced solid tumors overexpressing EGFR. Key eligibility criteria include 1) confirmed progressive disease on at least one line of systemic treatment, 2) EGFR overexpression or amplification documented in histology reports, 3) at least a 4 week or 5 half-lives window since last treatment, and 4) excluding subjects with long QT syndrome, multiple myeloma, multiple sclerosis, myasthenia gravis or uncontrolled infectious, psychiatric, neurologic, or cancer disease. Plasma and tissue samples will be investigated for pharmacodynamic and predictive biomarkers and genetic signatures associated with IFN-gamma secretion, aiming to select subjects for treatment in Phase 2. Conclusion: Through successful coupling of wild-type IL-2 with a high affinity IL-10 and targeting directly to the tumor microenvironment, DK210 (EGFR) has the potential to harness IL-2 and IL-10’s known anti-cancer promise while reducing immunogenicity and toxicity risks enabling safe concomitant cytokine treatment with other anti-cancer modalities.

Keywords: cytokine, EGFR over expression, interleukine-2, interleukine-10, clinical trial

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Authors: Petros Dlamini, Bethiweli Malambo, Maggie Masenya

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Knowledge management practices are very important in public libraries, especial in the era of the information society. The success of public libraries depends on the recognition and application of knowledge management practices. The study investigates the value and challenges of knowledge management practices in public libraries. Three research objectives informed the study: to identify knowledge management practices in public libraries, understand the value of knowledge management practices in public libraries, and determine the factors hampering knowledge management practices in public libraries. The study was informed by the interpretivism research paradigm, which is associated with qualitative studies. In that light, the study collected data from eight librarians and or library heads, who were purposively selected from public libraries. The study adopted a social anthropological approach, which thoroughly evaluated each participant's response. Data was collected from the respondents through telephonic semi-structured interviews and assessed accordingly. Furthermore, the study used the latest content concept for data interpretation. The chosen data analysis method allowed the study to achieve its main purpose with concrete and valid information. The study's findings showed that all six (100%) selected public libraries apply knowledge management practices. The findings of the study revealed that public libraries have knowledge sharing as the main knowledge management practice. It was noted that public libraries employ many practices, but each library employed its practices of choice depending on their knowledge management practices structure. The findings further showed that knowledge management practices in public libraries are employed through meetings, training, information sessions, and awareness, to mention a few. The findings revealed that knowledge management practices make the libraries usable. Furthermore, it has been asserted that knowledge management practices in public libraries meet users’ needs and expectations and equip them with skills. It was discovered that all participating public libraries from Umkhanyakude district municipality valued their knowledge management practices as the pillar and foundation of services. Noticeably, knowledge management practices improve users ‘standard of living and build an information society. The findings of the study showed that librarians should be responsible for the value of knowledge management practices as they are qualified personnel. The results also showed that 83.35% of public libraries had factors hampering knowledge management practices. The factors are not limited to shortage of funds, resources and space, and political interference. Several suggestions were made to improve knowledge management practices in public libraries. These suggestions include improving the library budget, increasing libraries’ building sizes, and conducting more staff training.

Keywords: knowledge management, knowledge management practices, storage, dissemination

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Authors: Karel Frana, Sylvio Simon

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The objective of the paper is a numerical study of heat transfer between perforated metal plates and the surrounding air flows. Different perforation structures can nowadays be found in various industrial products. Besides improving the mechanical properties, the perforations can intensify the heat transfer as well. The heat transfer coefficient depends on a wide range of parameters such as type of perforation, size, shape, flow properties of the surrounding air etc. The paper was focused on three different perforation structures which have been investigated from the point of the view of the production in the previous studies. To determine the heat coefficients and the Nusselt numbers, the numerical simulation approach was adopted. The calculations were performed using the OpenFOAM software. The three-dimensional, unstable, turbulent and incompressible air flow around the perforated surface metal plate was considered.

Keywords: perforations, convective heat transfers, turbulent flows, numerical simulations

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Authors: K. Shahril, M. Ridzuan, M. Sabri

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The disc rotor is solid, ventilated or drilled. The ventilated type disc rotor consists of a wider disc with cooling fins cast through the middle to ensure good cooling. The disc brakes use pads that are pressed axially against a rotor or disc. Solid and ventilated disc design are same which it free with any form, unless inside the ventilated disc has several ventilation holes. Different with drilled disc has some construction on the surface which is has six lines of drill hole penetrate the disc and a little bit deep twelve curves. From the thermal analysis that was conducted by using ANSYS Software, temperature distribution and heat transfer rate on the disc were obtained on each design. Temperature occurred on the drilled disc was lowest than ventilated and solid disc, it is 66% better than ventilated while ventilated is 21% good than solid disc.

Keywords: disc brakes, drilled disc, thermal analysis, ANSYS software

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Authors: C. Deangeli, P. Obentaku Obenebot, O. Omwanghe

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The study focuses on the analysis of wellbore instability in rock masses affected by weakness planes. The occurrence of failure in such a type of rocks can occur in the rock matrix and/ or along the weakness planes, in relation to the mud weight gradient. In this case the simple Kirsch solution coupled with a failure criterion cannot supply a suitable scenario for borehole instabilities. Two different numerical approaches have been used in order to investigate the onset of local failure at the wall of a borehole. For each type of approach the influence of the inclination of weakness planes has been investigates, by considering joint sets at 0°, 35° and 90° to the horizontal. The first set of models have been carried out with FLAC 2D (Fast Lagrangian Analysis of Continua) by considering the rock material as a continuous medium, with a Mohr Coulomb criterion for the rock matrix and using the ubiquitous joint model for accounting for the presence of the weakness planes. In this model yield may occur in either the solid or along the weak plane, or both, depending on the stress state, the orientation of the weak plane and the material properties of the solid and weak plane. The second set of models have been performed with PFC2D (Particle Flow code). This code is based on the Discrete Element Method and considers the rock material as an assembly of grains bonded by cement-like materials, and pore spaces. The presence of weakness planes is simulated by the degradation of the bonds between grains along given directions. In general the results of the two approaches are in agreement. However the discrete approach seems to capture more complex phenomena related to local failure in the form of grain detachment at wall of the borehole. In fact the presence of weakness planes in the discontinuous medium leads to local instability along the weak planes also in conditions not predicted from the continuous solution. In general slip failure locations and directions do not follow the conventional wellbore breakout direction but depend upon the internal friction angle and the orientation of the bedding planes. When weakness plane is at 0° and 90° the behaviour are similar to that of a continuous rock material, but borehole instability is more severe when weakness planes are inclined at an angle between 0° and 90° to the horizontal. In conclusion, the results of the numerical simulations show that the prediction of local failure at the wall of the wellbore cannot disregard the presence of weakness planes and consequently the higher mud weight required for stability for any specific inclination of the joints. Despite the discrete approach can simulate smaller areas because of the large number of particles required for the generation of the rock material, however it seems to investigate more correctly the occurrence of failure at the miscroscale and eventually the propagation of the failed zone to a large portion of rock around the wellbore.

Keywords: continuous- discontinuous, numerical modelling, weakness planes wellbore, FLAC 2D

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Authors: Eleni Ioannou, Pascal Nucara, Keith Pullen

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The subject of this paper is the investigation of the best efficiency design of a compressor diffuser applied in new lightweight, ultra efficient micro-gas turbine engines for vehicles. The Computational Fluid Dynamics (CFD) results are obtained utilizing steady state simulations for a wedge and an ”oval” type pipe diffuser in an effort to identify the beneficial effects of the pipe diffuser design. The basic flow features are presented with particular focus on the optimization of the pipe diffuser leading to higher efficiencies for the compressor stage. The optimised pipe diffuser is designed to exploit the 3D freedom enabled by Selective Laser Melting, hence purposely involves an investigation of geometric characteristics that do not follow the traditional diffuser concept.

Keywords: CFD, centrifugal compressor, micro-gas turbine, pipe diffuser, SLM, wedge diffuser

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Authors: Sergio A. Navarro Tuch, Martin Rogelio Bustamante Bello, Leopoldo Julian Lechuga Lopez

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In recent years, Mexico’s population has seen a rise of different physiological and mental negative states. Two main consequences of this problematic are deficient work performance and high levels of stress generating and important impact on a person’s physical, mental and emotional health. Several approaches, such as the use of audiovisual stimulus to induce emotions and modify a person’s emotional state, can be applied in an effort to decreases these negative effects. With the use of different non-invasive physiological sensors such as EEG, luminosity and face recognition we gather information of the subject’s current emotional state. In a controlled environment, a subject is shown a series of selected images from the International Affective Picture System (IAPS) in order to induce a specific set of emotions and obtain information from the sensors. The raw data obtained is statistically analyzed in order to filter only the specific groups of information that relate to a subject’s emotions and current values of the physical variables in the controlled environment such as, luminosity, RGB light color, temperature, oxygen level and noise. Finally, a neural network based control algorithm is given the data obtained in order to feedback the system and automate the modification of the environment variables and audiovisual content shown in an effort that these changes can positively alter the subject’s emotional state. During the research, it was found that the light color was directly related to the type of impact generated by the audiovisual content on the subject’s emotional state. Red illumination increased the impact of violent images and green illumination along with relaxing images decreased the subject’s levels of anxiety. Specific differences between men and women were found as to which type of images generated a greater impact in either gender. The population sample was mainly constituted by college students whose data analysis showed a decreased sensibility to violence towards humans. Despite the early stage of the control algorithm, the results obtained from the population sample give us a better insight into the possibilities of emotional domotics and the applications that can be created towards the improvement of performance in people’s lives. The objective of this research is to create a positive impact with the application of technology to everyday activities; nonetheless, an ethical problem arises since this can also be applied to control a person’s emotions and shift their decision making.

Keywords: data analysis, emotional domotics, performance improvement, neural network

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Authors: Young Nam Jo, Moon Jeong Kang, Hong Hee Yoo

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Most human vibration models have been modeled as a multibody system consisting of some rigid bodies and spring-dampers. These models are developed for certain posture and conditions. So, the models cannot be used in vibration analysis in various posture and conditions. The purpose of this study is to develop a human vibration model that represent human vibration characteristics under various conditions by employing a musculoskeletal model. To do this, the human vibration model is developed based on biomechanical models. In addition, muscle models are employed instead of spring-dampers. Activations of muscles are controlled by PD controller to maintain body posture under vertical vibration is applied. Each gain value of the controller is obtained to minimize the difference of apparent mass and acceleration transmissibility between experim ent and analysis by using an optimization method.

Keywords: human vibration analysis, hill type muscle model, PD control, whole-body vibration

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Authors: Dirk Briskorn, Michael Dienstknecht

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Cranes are a key element in construction projects as they are the primary lifting equipment and among the most expensive construction equipment. Thus, selecting cranes and locating them on-site is an important factor for a project's profitability. We focus on a site with supply and demand areas that have to be connected by tower cranes. There are several types of tower cranes differing in certain specifications such as costs or operating radius. The objective is to select cranes and determine their locations such that each demand area is connected to its supply area at minimum cost. We detail the problem setting and show how to obtain a discrete set of candidate locations for each crane type without losing optimality. This discretization allows us to reduce our problem to the classic set cover problem. Despite its NP-hardness, we achieve good results employing a standard solver and a greedy heuristic, respectively.

Keywords: positioning, selection, standard solver, tower cranes

Procedia PDF Downloads 359

Authors: Luisa Windhagen, Atsumi Hirose, Alex Bottle

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Global urbanization has resulted in the expansion of slums, leaving over 10 million Tanzanians in urban poverty and at risk of poor health. Whilst rural residence has historically been associated with an increased risk of adverse pregnancy outcomes, recent studies found higher perinatal mortality rates in urban Tanzania. This study aims to understand to what extent slum neighborhoods may account for the spatial disparities seen in Tanzania. We generated a slum indicator based on UN-HABITAT criteria to identify slum clusters within the 2015-2016 Tanzania Demographic and Health Survey. Descriptive statistics, disaggregated by urban slum, urban non-slum, and rural areas, were produced. Simple and multivariable logistic regression examined the association between cluster residence type and neonatal mortality and stillbirth. For neonatal mortality, we additionally built a multilevel logistic regression model, adjusting for confounding and clustering. The neonatal mortality ratio was highest in slums (38.3 deaths per 1000 live births); the stillbirth rate was three times higher in slums (32.4 deaths per 1000 births) than in urban non-slums. Neonatal death was more likely to occur in slums than in urban non-slums (aOR=2.15, 95% CI=1.02-4.56) and rural areas (aOR=1.78, 95% CI=1.15-2.77). Odds of stillbirth were over five times higher among rural than urban non-slum residents (aOR=5.25, 95% CI=1.31-20.96). The results suggest that slums contribute to the urban disadvantage in Tanzanian neonatal health. Higher neonatal mortality in slums may be attributable to lack of education, lower socioeconomic status, poor healthcare access, and environmental factors, including indoor and outdoor air pollution and unsanitary conditions from inadequate housing. However, further research is required to ascertain specific causalities as well as significant associations between residence type and other pregnancy outcomes. The high neonatal mortality, stillbirth, and slum formation rates in Tanzania signify that considerable change is necessary to achieve international goals for health and human settlements. Disparities in access to adequate housing, safe water and sanitation, high standard antenatal, intrapartum, and neonatal care, and maternal education need to urgently be addressed. This study highlights the spatial neonatal mortality shift from rural settings to urban informal settlements in Tanzania. Importantly, other low- and middle-income countries experiencing overwhelming urbanization and slum expansion may also be at risk of a reversing trend in residential neonatal health differences.

Keywords: urban health, slum residence, neonatal mortality, stillbirth, global urbanisation

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Authors: S. M. Golgoun, S. M. Taheri

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Investigation of radioactive contamination of personnel working in radiation centers to identify radioactive materials and then measure the potential contamination and eliminate it has always been considered. For this purpose, various ways have been proposed so far and different devices have been designed and built. Gas sealed proportional counter has special working conditions. In this research, a gas sealed detector of proportional counter type was made and then its various parameters were investigated. Some parameters are influential on their working conditions and one of these most important parameters is the internal pressure of the proportional gas-filled detector. In this experimental research, we produced software for examination and altering high voltage, registering data, and calculating efficiency. By this, we investigated different gas pressure effects on detector efficiency and proposed optimizing working conditions of this detector. After reviewing the results, we suggested a range between 20-30 mbar pressure for this gas sealed detector.

Keywords: gas sealed, proportional detector, pressure, counter

Procedia PDF Downloads 102