Hasil untuk "Manufactures"

Lía Caren Meyer, Gamaliel López, Alfredo Anibal Guillaumet et al.

La compresión axial en elementos de madera laminada encolada (glulam) requiere de un dimensionamiento preciso que considere tanto las propiedades mecánicas del material como los efectos de esbeltez. En este contexto, los reglamentos vigentes presentan limitaciones al aplicar valores únicos para los factores de estabilidad (CP) y de inestabilidad (Kc), sin contemplar las variaciones propias de cada especie ni los modos de falla por pandeo. El presente estudio aborda esta problemática mediante barras de madera laminada de Populus deltoides, con el objetivo de ajustar los parámetros “c” y “βc” que intervienen en el cálculo de dichos factores.  Se llevaron a cabo ensayos de compresión axial en un total de 320 probetas en el rango de esbeltez comprendido entre 30 a 100. A partir de los resultados experimentales de las tensiones de rotura del percentil 5 % y la resistencia a compresión paralela a las fibras, se determinaron los valores óptimos de los parámetros “c” y “βc”. El reglamento argentino usa un único valor de c=0,9 para piezas de madera laminada encolada de aplicación práctica. Sin embargo, este valor evidencia la necesidad de ajustes para mejorar el dimensionamiento en elementos comprimidos, obteniendo un valor menor de “c”. Por otro lado, el criterio europeo con βc = 0,1 tiende a sobrestimar las cargas de compresión. No obstante, el mayor valor de βc determinado con el programa experimental, presentó una mejor correlación para todas las esbelteces, reduciendo las sobrestimaciones de las cargas a compresión. Los resultados confirman que ajustar los parámetros “c” y “βc” mejora significativamente la precisión del dimensionado y optimizando el diseño en elementos comprimidos.

Alma De León-Hernández, Adriana Martínez-Hernández, Isabel Bolivar-Tellería et al.

Abstract BackgroundPressure ulcers constitute a major health care burden, characterized by significant morbidity, diminished quality of life, and elevated treatment costs. Wheelchair users are predisposed to pressure ulcers due to sustained ischial and sacral interface pressures resulting from prolonged periods of sitting. Implementation of pressure-relieving interventions, including specialized seating systems engineered to redistribute load and augment the weight-bearing surface area, is critical for mitigating the risk of pressure ulcers. ObjectiveThis study aimed to evaluate a methodology for the custom fabrication of pressure relief cushions, through the user-cushion interface pressure mapping to reduce high-pressure areas and increase contact area in wheelchair users. MethodsFirst, a validation study was carried out with 7 healthy volunteers. The pressure was determined with an FSA sensor (BodiTrak BT1510, Vista Medical Manufactures), and the cushion profile was obtained through a linear relation with pressure values. In the second phase, 10 cushions for wheelchair users were manufactured and tested. The resulting data from buttock pressure using a flat foam, Jay ResultsIn the validation study, the statistically significant difference between the flat and the custom-contoured cushion showed a better performance in pressure relief for the custom cushion (mean pressure 27.3, SD 4.5 mm Hg and 34.6, SD 3.5 mm Hg; PP2PP ConclusionsThe main finding is that the buttock pressure mapping method produces custom-contoured cushions that, compared with commercial cushions, have good pressure distribution and increased contact area. These results suggest that pressure mapping is a good alternative for manufacturing affordable custom-contoured cushions that can prevent the development of pressure ulcers.

Kamile Tırak Hızal, Turgay Birtürk

The increasing use of wood in the forest industry and reduction of forest resources have prompted the paper industry to look for new materials. To this end, this study examined the biometric coefficients of the seven woody stems grown in different regions and investigated suitability for papermaking as an alternative to the use of wood. Wood samples of each species were collected from two different regions in Türkiye: the Kozan region, which has a Mediterranean climate, and the Yuvacık region, which has a mostly oceanic climate.  The species included in the study were Phillyrea latifolia (mock privet), Arbutus andrachne (greek strawberry tree), Erica arborea (tree heath), Spartium junceum (spanish broom), Laurus nobilis (bay tree), Pistacia turpentine (cyprus turpentine tree), and Rhus coriaria (elm-leaved sumac). All fibers were classified as short. The longest fiber was observed for Spartium junceum (spanish broom) in Kozan. The fiber diameter was highest for Arbutus andrachne (greek strawberry tree) from Kozan, followed by Rhus coriaria (elm-leaved sumac) from Yuvacık and Laurus nobilis (bay tree) from Kozan. The fiber dimensions and the relationship between them were statistically analyzed. These included the slenderness ratio, flexibility coefficient, Runkel ratio, rigidity coefficient, Luce’s shape factor, F-factor, and Muhlsteph ratio. Although differences in fiber properties were detected between the two regions, it was determined that these were not enough to affect the desired properties for paper production. It was concluded that the fibers could be used in pulp, paperboard, and corrugated board production when mixed with long fibers.  

Siyu Zhou, Jiajun Qian, Han Xie et al.

FSP is a novel technology that can improve the microstructure and mechanical properties of ADED. In this study, an FSP-ADED hybrid manufacturing finite element model was constructed for stress and strain simulating the Ti–6Al–4 V alloy. The results show that continuous shrinkage of the deposition wall was broken after inter-layer FSP. The minimum tensile RS was obtained near the wall top. The tensile RS was increased after the deposition of the second layer; however, the overall stress level was lower than that of ADED alone. After two layers of FSP, the average value of longitudinal stress in the stirred zone was reduced by 54%. The warping deformation of hybrid manufactured components was reduced by 30.9%. It was proved that FSP-ADED hybrid manufacturing is an effective method to reduce RS and deformation of titanium alloy large-scale structural parts in the aerospace field.

Endy Tuhumury, Martinus Parnawa Putranta, Mpholle Clement Paepae

The quest to provide excellent services causes the aviation industry face challenges that can impair the well-being or “happiness” of its employees. Therefore, managing employee well-being is crucial for the industry to help its employees feel positive while serving the companies. This research aimed to examine the roles of followership styles, job satisfaction and perceived supervisor support in promoting psychological well-being in the Indonesian air transport operator contexts. Specifically, the research examined the impact of job satisfaction on psychological well-being and assessed whether job satisfaction itself was influenced by employees’ followership styles and their perceived supervisor support. A test was also performed to examine the moderating role of perceived supervisor support in the relationship between followership styles and job satisfaction. On-line questionnaires were distributed to potential respondents using a combination of convenience and purposive sampling.  A number of 109 non-managerial employees from several Indonesian commercial and non-commercial air transport operators involved.  Structural Equation Modeling was adopted to test the proposed hypotheses. The findings showed the majority of respondents enacted “exemplary followership” styles. This style positively related to job satisfaction. However, perceived supervisor support was not found to moderate the relationship. The managerial implication of the findings is outlined.

JongHyun Kim, JaeHyoung Yun, Seon Il Kim et al.

A convolutional neural network (CNN) guided Bayesian optimisation framework is introduced to strategically maximise the surface to volume ratio of 3D printed lattice supercapacitors. We applied Bayesian optimisation on printing parameters to exploit regions where uniform and narrow lines are printed. A line shape classifying CNN model guided the optimiser’s search space to straight-line printed regions, minimising optimisation time and cost. An automatic scoring method allowed each iteration to be conducted within two minutes with accurate and precise measurements. The optimisation process has been demonstrated with graphene oxide (GO) and poly(3,4-ethylenedioxythiophene):polystyrene sulphonate (PEDOT:PSS) inks. The results were compared to the parameters that follow the conventional methodologies of direct ink writing (DIW) 3D printing. For each printed line of GO and PEDOT:PSS inks, irregularities decreased by 61.8% and 18.9% and average widths decreased by 39.0% and 28.6%. PEDOT:PSS lattice supercapacitor printed using optimised result showed a 151.0% increase in specific capacitance.

Hanieh Shambayati, Mohsen Shafiei nikabadi, Seyed Mohammad Ali Khatami Firouzabadi et al.

Purpose: Today, the manufacturing industry, with the expansion of the physical constraints of trade worldwide, has adopted modern information technologies to optimize the business process and achieve integration with geographically dispersed supply chain partners. Traditional supply chain models focus on optimizing physical flows. However, it is equally important to ensure that physical units can process appropriate information. This paper aims to propose a model for the optimization of information process performance in the IoT-based virtual supply chain. Design/methodology/approach: In this study, information processing performance in the closed-loop virtual supply chain has been optimized to maximize profit and information processing speed by considering costs of virtual, information security, and energy consumption. The final programming model has been optimized using meta-heuristic algorithms, the Non-Dominated Sorting Genetic Algorithm II (NSGA-II), and the Strength Pareto Evolutionary Algorithm (SPEA-II).Findings – The results indicated that there is an inverse relationship between virtual supply chain profit and information processing speed (delay). The results of model solving using NSGA-II and SPEA-II algorithms underlined the virtual supply chain profit of 9.93×106 and 4.23×106, and the data processing speed of 337.48 and 94.07, respectively. Thus, the NSGA-II algorithm contributes more to the supply chain profitability.Research limitations/implications - The proposed model can be used in manufacturing industries equipped with IoT. Unavailability of practical examples and insufficient data are the two main limitations of the study. Practical implications:- The proposed model improves the production process and helps managers to plan better for their supply chain management and make timely decisions by sharing information across the supply chain and being aware of the flows of products and associated parts.Social implications - The Internet of Things in the virtual supply chain provides an opportunity to manage logistics systems and results in efficient online delivery with minimal cost. The information flow integrates all links and participants in the virtual supply chain. It enables each member to obtain the accurate information needed for logistics capability, reduces resource wastage, and improves customer satisfaction. Originality/value: One of the innovative aspects of this research is the use of IoT in the virtual supply chain for the integration and transparency of information in the supply chain, considering the importance of information in the virtual supply chain and examining the impact of IoT usage on closed-loop virtual supply costs and target functions. In addition to considering the physical flow costs of the closed-loop, including production costs, separation costs, repair, disposal, recycling, etc., in the cost objective function, virtual flow costs included IoT usage costs and information security costs. Energy consumption was also included in the objective function. Also, due to the virtualization of the supply chain and the significant role of information, optimization of information processing speed was considered in modeling the supply chain performance, which is another innovative aspect of research.

Deoclécio Junior Cardoso da Silva, Denise Adriana Johann, Andrieli de Fátima Paz Nunes et al.

Diante aos aspectos inerentes que permeiam a temática da sustentabilidade, bem como a importância desta na sociedade, torna-se relevante que estudos sejam realizados com a finalidade de auxiliar as organizações a estarem alinhadas a esse viés. Dessa forma objetivo do presente estudo é avaliar as alternativas de melhoria na qualidade no processo com ênfase nas práticas sustentáveis em um restaurante situado na região noroeste do Rio Grande do Sul. Através de uma pesquisa exploratória, descritiva, de abordagem qualitativa e quantitativa, este estudo de caso avaliou um restaurante, elencando alternativas de melhoria da qualidade, alinhadas a práticas sustentáveis, priorizando através do método de Análise hierárquica de processos (AHP) aquela que na visão do gestor é mais relevante. Dessa forma, os resultados demonstraram que alternativa voltada a treinamento do pessoal é a mais priorizada, visto sua influência direta nos processos, o que pode auxiliar na redução dos desperdícios no restaurante.

Sotaro Sada, Yuichi Ikeda

Global value chains are formed through value-added trade, and some regions promote economic integration by concluding regional trade agreements to promote these chains. However, it has not been established to quantitatively assess the scope and extent of economic integration involving various sectors in multiple countries. In this study, we used the World Input-Output Database to create a cross-border sector-wise network of trade in value-added (international value-added network) covering the period of 2000-2014 and evaluated them using network science methods. By applying Infomap to the international value-added network, we confirmed two regional communities: Europe and the Pacific Rim. We applied Helmholtz-Hodge decomposition to the value-added flows within the region into potential and circular flows, and clarified the annual evolution of the potential and circular relationships between countries and sectors. The circular flow component of the decomposition was used to define an economic integration index. Findings confirmed that the degree of economic integration in Europe declined sharply after the economic crisis in 2009 to a level lower than that in the Pacific Rim. The European economic integration index recovered in 2011 but again fell below that of the Pacific Rim in 2013. Moreover, sectoral economic integration indices suggest what Europe depends on Russia in natural resources makes the European economic integration index unstable. On the other hand, the indices of the Pacific Rim suggest the steady economic integration index of the Pacific Rim captures the stable global value chains from natural resources to construction and manufactures of motor vehicles and high-tech products.

HARIKA VANGARA, USHA KALAWAT, B SIDDHARTHA KUMAR et al.

Introduction: Rapid antigen testing can help in early diagnosis of Influenza in resource limited settings in patients presenting with Influenza Like Illness (ILI). Aim: To evaluate the usefulness of Rapid Influenza Direct antigen Testing (RIDT) in comparison to Real Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) for diagnosis of Influenza virus infection in clinically suspected patients with ILI in a tertiary care hospital. Material and Methods: A prospective observational independent study was done to evaluate RIDT for Influenza virus infection, considering RT-PCR as gold standard. Throat swabs and nasal swabs from patients meeting Category 3 definition of ILI by Ministry Of Health and Family Welfare (MOHFW) were collected from July 20th, 2019 to October 20th, 2019 from hospitals in and around the study area. Onsite Rapid test (Biogenix, China) was used as per manufactures instructions for rapid detection of Influenza antigen. RNA extraction was done using Qiagen kit followed by RT-PCR using primer, probes recommended by National Institute of Virology (NIV, Pune) as per their protocols. Data was recorded on a predesigned proforma and managed using Microsoft Excel 2018 (Microsoft Corp, Redmond, WA). The Statistical software MedCalc version 9.1 for Windows was used for data analysis. Results: The overall sensitivity of the RIDT was 37.9% and specificity was 94.4%. The Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were 73.3% and 78.8%, respectively. Kappa was calculated to be 0.37 that suggested a fair agreement between RIDT and RT-PCR. When the Cycle threshold (Ct) values were compared to the results of RIDT, there were more false positives at low Ct value and more false negatives at high Ct values. Conclusion: The RIDT is not useful in screening during an outbreak in acute care settings. The negative result of RIDT should be followed up with RT-PCR. With a strong clinical suspicion, it is better to start antivirals than wait for laboratory report in severely ill patients with ILI.

Kang Tang, Hui Ma, Yujia Tian et al.

Micro-supercapacitors (MSCs) with excellent electrochemical behaviours and flexibility possess great promise for portable and wearable electronic devices. A novel type of hybrid-dimensional Fe2O3/graphene/Ag ink is developed and extruded into MSC electrodes through the direct ink writing-based three-dimensional (3D) printing. The optimal solid-state MSC device exhibits a maximum areal capacitance of 412.3 mF cm−2 at 2 mA cm−2, a correspondingly high energy density of 65.4 μWh cm−2 and 89% capacitance retention for over 5000 charge and discharge cycles. The superior electrochemical performance is profited by the high electron transport synergistically boosted by two-dimensional graphene nanosheets and one-dimensional Ag nanowires, and the high pseudocapacitive behaviours of Fe2O3 nanoparticles. The 3D printed MSC exhibits reliable flexibility with remarkable retention of 90.2% of its original capacitance after 500 bending cycles. The current 3D printing fabrication demonstrates an efficient route for advanced miniaturised electrochemical energy storage.

Xi Zhang, Enquan Liang

Additive Manufacturing (AM) has huge advantages in prototyping and rapid manufacturing, also potentials in integrated design, cost and weight reduction, which are suitable for applications in aircraft. In recent years, aircraft manufactures as well as aviation authorities have made significant progress in Metal Additive Manufacturing components and structures, from materials and processes, to authority approval. Also, new AM technologies are still under rigid development, many of which have even more potentials than current favorite processes like selected laser melting (SLM), wire-arcing additive manufacturing (WAAM). However, as the first and overall requirement for aircraft, security level of AM components are still in question. Stability in mechanical properties, researches in fatigue and defect and issues in AM certification are major concerns for manufactures before AM technologies are really and widely used in aircraft design and manufacturing.

Muhsin A., Budaya P.W.

PT XYZ Indonesia is a pharmaceutical company that manufactures medicines, clinical nutrition, intravenous fluids, and medical tools. PT XYZ has a Quality Control Department which includes several divisions. Based on observations, the workload of workers in the Biology Division Quality Control Department is quite high; the job description that has been determined by the company is only done by a workforce of 9 people and 1 supervisor, causing fatigue due to excessive workload. The workload calculation was done by using the Workload Analysis method. The first step was to observe the level of worker productivity using work sampling, determine the value of Performance Rating, Allowance, workload value, and the number of proposed workers. The amount of workload received by workers was then used to determine the number of workers who should be employed so that the employee will not have excessive workloads. The workload calculation results show that 9 workers have a high workload of 161%. The proposed improvement given to overcome this high workload is to add 6 workers.

Melikhova Tetiana, Makarenko Andriy, Mikhailytsa Olena et al.

In present work, the peculiarities of simulation model of enterprises bankruptcy probability that exist in European, world and domestic practices were considered. The scientific econometric approach was applied to determine the overall presence and strength of the relation between the economic indicators of industrial enterprises. A financial analysis of large industrial manufactures in the region of Ukraine was conducted. To form the information base of the study, the authors estimated liquidity, solvency, business activity and profitability ratios that affect the financial condition of enterprises. They revealed the most significant ratios of financial condition analysis. According to the analysis of existing models of bankruptcy probability in the context of these industrial enterprises, an improved model for assessing the risk of bankruptcy was proposed and evaluated. The proposed model for estimating the probability of bankruptcy, taking into account the influence of the most significant ratios of financial analysis, confirmed that the percentage of provided bankruptcies and stable activities are acceptable and indicate high quality of the resulting equation. The IBM SPSS Statistics system was used to process the data, check the assumptions and prepare valid conclusions. The improved model will allow it to be used in the practice of diagnosing the probability of bankruptcy of industrial enterprises, which will help identify the threat of bankruptcy in time and ensure stable operation of the industrial enterprise.

F. P. Bos, E. Bosco, T. A. M. Salet

With the number of 3D printed concrete structures rapidly increasing, the demand for concepts that allow for robust and ductile printed objects becomes increasingly pressing. An obvious solution strategy is the inclusion of fibers in the printed material. In this study, the effect of adding short straight steel fibers on the failure behaviour of Weber 3D 115-1 print mortar has been studied through several CMOD tests on cast and printed concrete, on different scales. The experiments have also been simulated numerically. The research has shown that the fibers cause an important increase in flexural strength, and eliminate the strength difference between cast and printed concrete that exists without fibers. The post-peak behaviour, nevertheless, has to be characterised as strongly strain-softening. In the printed specimens, a strong fiber orientation in the direction of the filament occurs. However, this has no notable effect on the performance in the tested direction: cast and printed concrete with fibers behave similarly in the CMOD test. For the key parameters, no scale effect was found for the specimens with fibers, contrary to the ones without. Numerical modelling of the test by using the Concrete Damage Plasticity material model of Abaqus, with a Thorenfeldt-based constitutive law in compression and a customised constitutive law in tension, results in a reasonable fit with the experimental results.

F. Berg, Christian Bøge Lyndgaard, K. Sørensen et al.

R. Rowthorn, R. Ramaswamy

This paper shows that deindustrialization is explained primarily by developments that are internal to the advanced economies. These include the combined effects on manufacturing employment of a relatively faster growth of productivity in manufacturing, the associated relative price changes, and shifts in the structure of demand between manufactures and services. North-south trade explains less than one-fifth of deindustrialization in the advanced economies. Moreover, the contribution of north-south trade to deindustrialization has been mainly through its effects in stimulating labor productivity in northern manufacturing; it has had little enduring effect on the total volume of manufacturing output in the advanced economies.

Randy A. Becker, Carl Pasurka, Ronald J. Shadbegian

Wrona Paweł, Różański Zenon, Pach Grzegorz et al.

The paper presents the results of numerical simulations into the distribution of methane concentration at the intersection of two excavations with a fan (turned on) giving the air stream to the area of the crossing. Assumed case represents emergency situation related to the unexpected flow of methane from an excavation and its mixing with fresh air. It is possible when sudden gas outburst takes place, methane leaks from methane drainage system or gas leaks out the pipelines of underground coal gasification devices. Three options were considered - corresponding to three different speeds of the jet fan. They represent three stages of fan work. First - low air speed is forced by a pneumatic fan, when electricity is cut off after high methane concentration detection. Medium speed can be forced by pneumatic-electric device when methane concentration allows to turn on the electricity. Third, the highest speed is for electric fans. Simulations were carried out in the Fire Dynamics Simulator (FDS) belongs to the group of programs Computational Fluid Dynamics (CFD). The governing equations are being solved in a numerical way. It was shown that proposed solution allows partial dilution of methane in every variant of speed what should allow escape of the miners from hazardous area.

IOVAN-DRAGOMIR Alina, DRIȘCU Mariana

A computer assisted procedure for the cinematic analysis of the mechanism of a cam is essential in making a certain type of research operations. They mainly refer to the optimization of operations running on specific machinery, or to the re-design of the mechanism, in order to make the mechanism digital. This analysis seems even more important, when we consider the fact that most of the machines used in shoe industry nowadays use a cam mechanism. The paper is devided in two parts. In first part, it is elaborated a method of finding of a function G(x), belonging to a Fourier series, which approximates the numerical values {xi, yi}, with the biggest accuracy. Finding the function that approximates the most accurately the data set, for the position parameters of the follower S(ω), () will lead to a complete kinematic and dynamic analysis of the cam mechanism. These values repeat with T = 2π period. In second part, the method is tasted using MatCAD work sessions which allow a numerical and graphical analysis of the mathematical relations involved, in order to test the reability of the method. The set of experimental data are resulted after measuring a cam mechanism of a machine used in shoemaking.