این پژوهش با هدف ارزیابی تأثیر پوششهای امولسیونی بر پایه نانوکریستالهای سلولز باکتریایی (BCNCs) و ژلاتین (GelA)، حاوی اسانس دارچین (CEO) در سه سطح غلظتی (۱۲۰۰، ۱۸۰۰ و μL/L ۲۴۰۰)، بر روند رسیدگی و پیری میوه سیب رقم گلدن دلیشز طی دوره نگهداری سرد (۶۰ روز در دمای 4 درجه سلسیوس) انجام گرفت. نتایج نشان داد که اعمال پوششها، افت وزن میوه را در مقایسه با نمونههای فاقد پوشش از حدود ۶۸/۱۴ درصد به حدود ۸۹/۸ درصد در تیمار حاوی μL/L ۲۴۰۰ اسانس دارچین کاهش داد. همچنین، افزایش غلظت اسانس دارچین با میزان نرخ تنفس و تولید اتیلن رابطه مستقیم داشت. نمونههای پوششدار در تمام سطوح غلظتی، سفتی بافت بالاتری نسبت به نمونههای شاهد نشان دادند و بیشترین سفتی مربوط به غلظت μL/L ۲۴۰۰ اسانس دارچین بود (N ۲۳/۱۸ در غلظت μL/L ۲۴۰۰ در مقایسه با N ۶۹/۱۶ در غلظت μL/L ۱۲۰۰ بعد از ۶۰ روز). این روند با تغییرات مشاهدهشده در شاخصهایی نظیر: اسیدیته قابل تیتراسیون، مواد جامد محلول، pH، محتوای اسید آسکوربیک و فعالیت آنزیمهای پلیفنلاکسیداز (PPO) و پراکسیداز (POD) همخوانی داشت. در مجموع، استفاده از سامانههای پوششی BCNCs–GelA/CEO موجب حفظ کیفیت فیزیکوشیمیایی سیبها، کنترل روند پیری و افزایش ماندگاری آنها در شرایط سرمایی شد. نتایج این پژوهش نشان میدهد که بهکارگیری چنین پوششهایی میتواند راهکاری مؤثر برای افزایش دوام پس از برداشت و کاهش افت اقتصادی در زنجیره تأمین میوههای تازه باشد.
Kimia Aghamohammadesmaeilketabforoosh, Joshua Givans, Morgan Woods
et al.
Distributed recycling and additive manufacturing (DRAM) offer a unique promise for obtaining a circular economy. To maintain or even enhance the value of common 3D printing feedstocks like polylactic acid (PLA) waste an approach to further incentivize prosumers to use recycled feedstocks is to provide something the market currently does not—custom filament colors. To enable prosumers to create custom colors from their own recycled 3D printing waste this article presents a new open-source software named SpecOptiBlend. Specifically, this study introduces a novel method for customizing color filaments by recycling waste 3D printing samples, thereby enhancing the capabilities of color 3D printing. Traditional 3D printing is limited by a narrow range of filament colors, and even multi-color printing heads can utilize only a limited number of colored filaments among the available options. The new approach here repurposes discarded prototypes and unused samples back into the printing cycle with desired colors, allowing for a broader spectrum of colors and gradients. This enables engineers and designers to create more intricate and functionally graded materials. To do this, waste plastics are quantified after processing for spectral reflectance, then Kubelka-Munk theory provides the initial estimate for color mixing. Three discrete optimization techniques are applied: Nelder-Mead, Limited-memory BFGS with bounds, and Sequential Least Squares Quadratic Programming. To determine the optimal method, assessment criteria include the application of root mean square (RMS) and the color difference (ΔE CIE-2000). Three case studies were conducted, and the Nelder-Mead method was found to provide an optimal balance between the precision of color differences and the RMS, essential for producing high-quality colors. This research has provided a free tool that will now enable prosumers to convert their plastic waste into specific custom colors to enable DRAM.
Metal products fabricated by additive manufacturing (AM), face challenges in mechanical property evaluation due to the complex thermal history of the process. This study used Ti-6Al-4V alloy, widely used in AM to examine the applicability of the Gibson-Ashby model for samples with porosities lower than 5%. Observations from electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) demonstrated that the Gibson-Ashby model's accuracy is limited due to the changes in the topology of pores and the phase proportions from different processing parameters. However, adaptive neuro fuzzy inference systems (ANFIS) reduced prediction errors on Young's modulus to 0.66 GPa and quantified the combined influence of microstructure variations. The proposed deviation factor addressed the model's neglect of microstructural changes. This laid the foundation for the establishment of a database to precisely control the mechanical properties of the products, thus promoting the optimisation of AM-produced titanium alloy for further practical applications.
TC4 particles reinforced AZ31 composite was successfully prepared by innovatively using simultaneous feeding method of powder and wire in wire-arc directed energy deposition (WA-DED). The results indicated that TC4 particles are expected to be evenly distributed in the AZ31 matrix and the introduced TC4 particle content of 9%−33.43 wt% can be acquired by adjusting the turret speed (TS) of powder feeder. The coarse columnar grains in the AZ31 transforms into the equiaxed grains after adding TC4 particles. A large number of acicular/flake Mg-Al phase and partial granular Al-Mn phase are formed around TC4 particles. The excellent tensile properties with yield strength of 85.6 MPa, ultimate tensile strength of 195 MPa and tensile elongation of 7.1% are obtained at the TS of 5 rpm, the corresponding maximum improvement efficiency reaches up to 42.6%. The improved strength mainly derives from grain refinement strengthening and thermal mismatch strengthening.
Clarissa Maria Rodrigues de Oliveira, Paula Cristina de Amorim Andrade, Maria Socorro Ferreira dos Santos
O intenso aumento da geração de resíduos sólido associado as práticas inadequadas de descartes corroboram com a necessidade do desenvolvimento de alternativas para o reaproveitamento de materiais de maneira a mitigar, sobretudo, os danos ao meio ambiente. Dentre esses materiais, destaca-se o óleo vegetal residual (OVR), o qual possui um elevado potencial poluidor e é amplamente utilizado em estabelecimentos comerciais e usuários domésticos. Nesse sentido, o presente estudo apresenta a avaliação da cadeia reversa do OVR destinado à fabricação de biodiesel mediante a realização de uma revisão sistemática na literatura. Dessa maneira, foi possível investigar e levantar informações acerca dos fatores relativos à articulação e instituição dessa cadeia, bem como contribuir para mitigar as lacunas nas discussões científicas presente na literatura sobre a temática estudada.
Production management. Operations management, Production capacity. Manufacturing capacity
Additive manufacturing technologies have a great potential for use in the manufacture of flexible sensors and in recent years, rapid research advances have been achieved in this field. Moreover, by combining textiles with printing technologies, novel sensing structures can be developed, eliminating the disadvantages of rigid sensors. These sensors are in great demand in various applications from the field of wearable e-textiles, such as sports, rehabilitation, and in medical tasks like vital sign monitoring. Printing makes possible to design patterns with complicated structures that could not be possible with the traditional weaving techniques, for example, because of the lack of precision. This also allows the use of a wide range of materials with advanced properties. Flexible sensors require flexible materials that can withstand the mechanical demands of bending, twisting or compression, provide comfort and most importantly withstand repeated washing cycles.
In this document, we briefly overview the flexible sensors manufactured via different printing approaches and the flexible materials developed by recent studies in this area. Moreover, we discuss a hot topic in current research: self-powered flexible sensors. These sensors eliminate the need for an external power source, enabling fully portability and lightweight wearable devices. On the other hand, we present some challenges encountered in the field of flexible printed sensors.
Green human resource management practices in the presence of green servant leadership have become a prime business concern for sustainable growth. This study examines the mediating role of green HRM practices between green Servant leadership and sustainable firm performance, particularly in the manufacturing sector. Cross-sectional data were collected from 480 owners/human resource managers working in the manufacturing industry in Pakistan using a convenient sampling technique. A partial least squares approach was applied to test the hypothesized relationships. The research findings suggest that Green Servant leadership and Sustainable Firm Performance are mediated by Green Human Resource Management Practices (GHRM). This empirical study contributes to the literature by considering GHRM as a mediator using the theoretical lens of stakeholder theory and resource-based view.
Business, Production management. Operations management
The current research study aimed to explore the utility of selected problem-solving tools and techniques in root-cause analysis to demonstrate their practical application. An experimental research design adopting a positivist empirical approach with a deductive strategy was followed to assess the effectiveness of a combined (8D & Six Sigma) problem-solving approach in reducing a high defects rate of a mixer shower assembly line. A novel application of the 8D framework in combination with Six Sigma and other analytical tools was found highly effective in reducing the reject rate from 11.84% to 0.11%. Successful identification of the root cause led to the implementation of permanent corrective action ensuring a long-term stable assembly process. The research study provided a problem-solving framework that was found effective in resolving a complex problem and implementing long-term corrective action in an assembly production line. However, this framework can be used in other industries. The research study provides a solution to a high number of leak rejects in a sub-assembly where "O-seals" are used between mating parts. It also provides analytical tools that were found highly effective during the problem-solving process.
The direct-digital upper-limb orthopaedic splinting process employs portable 3D scanning systems to capture anatomical surface geometry. However, the resultant quality of a complete upper-limb scan geometry may be detrimentally affected by involuntary movements of an unsupported limb, and the inability to maintain the correct posture due to patient disability. The aim of this research study is to develop an upper-limb 3D scanning posture-correction procedure that addresses these limitations. The methodology covers four stages: (a) 3D scanning; (b) rigging; (c) posture correction; and (d) geometry inspection. Manual and semi-automated rigging procedures were developed to define segments and joints of the wrist on the upper-limb scans. A semi-automated definition was developed to precisely and repeatedly articulate the defined hand segment. To assess feasibility and accuracy of the developed posture-correction procedure, the hand segment on scans in neutral hand posture were articulated with the developed posture-correction procedure as closely as possible to the corresponding hand positions on the scans in extended hand postures. The reported virtual posture-correction procedure provides a basis for research into anatomy articulation and the optimisation of complex splints and orthoses.
Abstrak
Kesuksesan entrepreneur diukur dari kehandalannya menggabungkan atau mengkombinasikan aset berwujud dan tak berwujud yang dimiliki UKM sehingga mampu mendobrak semua hambatan yang dihadapi UKM yaitu keterbatasan akses pasar dan akses modal, sumber daya yang cenderung rendah, minimnya modal kerja maupun rendahnya kemampuan untuk memanfaatkan peluang pasar yang ada. Berbagai perilaku yang digunakan entrepreneur dalam menjalankan bisnisnya maupun berinteraksi dengan stakeholder mengarah pada relasional jejaring dan kompetensi sosial yang harus dimiliki oleh seorang entrepreneur. Penelitian ini bertujuan untuk menguji faktor yang mampu memperluas relasional jejaring entrepreneur dan faktor konsekuensi dari adanya relasional jejaring yang dimiliki oleh seorang entrepreneur. Faktor-faktor tersebut sangat berkaitan dengan pencapaian kinerja bisnis pada UKM. Populasi penelitian ini adalah UKM sektor manufaktur di wilayah Surakarta dengan sampel sebanyak 127 UKM. Metode pemilihahan sampel adalah convenience sampling dan dianalisis menggunakan Structural Equation Modeling (SEM) dengan bantuan Partial Least Square (PLS) dalam pengolahan data penelitian. Hasil analisis data menunjukkan kinerja bisnis dapat dijelaskan oleh kompetensi sosial, relasional jejaring dan orientasi berbagi pengetahuan sebesar 69.5%. Adapun hasil pengujian hipotesis menunjukkan kinerja bisnis dipengaruhi oleh kompetensi sosial, relasional jejaring dan orientasi berbagi pengetahuan. Selain itu kompetensi sosial berpengaruh pada relasional jejaring dan relasional jejaring memberi pengaruh pada orientasi berbagi pengetahuan.
Kata Kunci : kompetensi sosial, relasional jejaring, berbagi pengetahuan, kinerja bisnis
Abstract
The success of the entrepreneur is measured by reliability merge or combine the tangible assets and intangible owned by SMEs so as to break down all the barriers faced by SMEs is limited access to markets and access to capital, resources tend to be low, the lack of working capital and lack of ability to take advantage of market opportunities. The various behaviors used by entrepreneurs in conducting their business or interacting with stakeholders lead to the relational networking and social competence that an entrepreneur must possess. This study aims to examine the factors that are able to expand the relational network of entrepreneurs and the consequence factors of the existence of relational networks owned by an entrepreneur. These factors are closely related to the achievement of business performance on SMEs. The population of this study is SME manufacturing sector in the Surakarta region with a sample of 127 SMEs. The method of sample selection is convenience sampling and analyzed using Structural Equation Modeling (SEM) with Partial Least Square (PLS) aid in data processing research. The results of data analysis show business performance can be explained by social competence, network relational and knowledge sharing orientation of 69.5%. The results of hypothesis testing show business performance is influenced by social competence, network relational and knowledge sharing orientation. In addition, social competence affects the relational networks and relational networks affect the orientation of knowledge sharing.
Keywords: Social Competence, Network Relational, Knowledge Sharing, Business Performance
Production management. Operations management, Management. Industrial management
It is necessary in factories to assess the severity of the surface defects of castings, as a slight surface defect will be taken as qualified when it brings no bad effect or it can be removed by the subsequent processing. In practical production, professional technicians visually inspect the surface defect severity according to their individual experience. Therefore, it is difficult for them to maintain the same standard and accuracy in the subjective, tedious and labor-intensive work. Recently, image processing techniques based on optical images have been applied to achieve better accuracy and high efficiency. Unfortunately, optical images cannot directly quantify surface depth, which works as a crucial factor in the practical assessment of surface defect severity. The surface roughness evaluation algorithm, which takes into account of both area and depth information of the assessed surface, was applied to directly characterize surface defect severity based on surface asperity rather than optical image. The results using standard casting pieces show that surface defect severity has no apparent dependence on surface roughness. However, the subsequent results show that the root-mean-squared-deviation (RMSD) of surface gradient of flow line defects positively correlates with the increase of defect severity. The other types of defect do not present such tendency. Thus, practical workpieces with flow line defects on the surface were used to verify the universality of this tendency. The results show that surface roughness of an unqualified workpiece is larger than that of a qualified workpiece after surface slope adjustment, but presents no obvious coincidence before the adjustment. In contrast, the RMSD of an unqualified workpiece, no matter before or after the adjustment, is larger than that of a qualified one.
It is known that regulations allow the introduction in production regimes efficient operation of equipment and methods of rational organization of production. To ensure accuracy imposed regulations must meet the following conditions: to take into account the main factors influencing consumption of work; depending on the types of production which they are intended to ensure adequate precision. In this work the analysis literature authors proposed a new relationship for calculating the standard time for the operation of thinning also set the value of two coefficients K1 and K2. K1 is a constant coefficient for thinning operation of 1,0549; and K2 - a constant that depends on the degree of automation of the machine. Knowing the degree of mechanization machines and time required to perform operation coefficient was determined K2, namely Km – 1,0833; KM – 1,0460; KA – 0,0785. Since the relationship for the calculation of the time aids not it into consideration that a part may contain from 3 to 5 types of profiles, it has been proposed that it be included in the relationship, so there was obtained a new relationship calculation. The study conducted also allowed the optimization of computing time assistant relationship, including the number of adjustments in relation computing machine. Proper use of normative values, taking into account the type of machine, but also their knowledge calclulul methodology allow us to identify the following positive effects on the company's footwear: reducing workload; achieving balanced labor standards; saving human effort; reducing worker fatigue etc.
Spectral analysis is the key tool for the study of vibration signals in rotating machinery. In this work, the vibration analy-sis applied for conditional preventive maintenance of such machines is proposed, as part of resolved problems related to vibration detection on the organs of these machines. The vibration signal of a centrifugal pump was treated to mount the benefits of the approach proposed. The obtained results present the signal estimation of a pump vibration using Fourier transform technique compared by the spectral analysis methods based on Prony approach.
The occurrence of size effects in microforming process may result in nonhomogeneous material characteristics. Heat assisted microforming is an effective approach to reduce the influence of size effects. To improve the heating rate, resistance heating method is introduced to the microforming process. To investigate the size effect of heat on material deformation for thin foils in microforming, uniaxial tensile tests were performed for the foils with different grain sizes at different temperatures by tensile testing system incorporating with resistance heating method. The results show that the reduction of the stress at elevated temperatures compared to room temperature is higher for the foils with larger grain size than that for the foils with smaller grain size. The fracture strain decreases with increasing temperature when the temperature is below 300 °C, and then increases as the temperature increases when the temperature is above 300 °C. In addition, the work hardening behavior of the material is independent of the grain size. As temperature increases, the work hardening increases.
Henrique Trevisan, João Vicente de Figueiredo Latorraca, Angelo Luíz Pacheco dos Santos
et al.
The objective was to evaluate the elasticity dynamic modulus reduction (MOEd) and deterioration of E. grandis thermorectificated wood by exposure to environmental weathering. Six trees were used to obtain 14 logs of 2,4m, with seven from external (sapwood) and the others from internal (heartwood) part of the trunk. A total of 84 wood samples of 2,5x 5x 50cm were made, with half from the inner and the other from the external trunk portion. 14 treatments were evaluated with six replicates composed of thermorectificated wood submitted two differents times (2 and 4 hours) and three temperatures (200, 215 and 230˚C). An ultrasound Stress Wave Timer device was used to evaluate MOEd and the mass measured by weighing. Samples remained in the decay test field for ten months, and monthly inspected and recorded to xylophogous organism’s occurrence. At the end of this period MOEd and mass were revaluated. The central portion of wood samples were more deteriorated, with mass losses and stiffness losses ranging from (8-56%) and (18-91%), respectively. Lower values were observed in the wood coming from the external portion, with mass losses and stiffness ranging from (3-10%) and (8-20%), respectively. The thermorectificated wood samples were more damaged by action the termites and less by the action of fungi, compared to controls.
The iron-rich solids formed during solidification of Al-Si alloys which are known to be detrimental to the mechanical, physical and chemical properties of the alloys should be removed. On the other hand, Al-Si hypereutectic alloys are used to extract the pure primary silicon which is suitable for photovoltaic cells in the solvent refining process. One of the important issues in iron removal and in solvent refining is the effective separation of the crystallized solids from the Al-Si alloy melts. This paper describes the separation methods of the primary solids from Al-Si alloy melts such as sedimentation, draining, filtration, electromagnetic separation and centrifugal separation, focused on the iron removal and on the separation of silicon in the solvent refining process.
Se ofrece una valoración sobre la importancia de la implementación dela mediación como método alternativo para la solución de los conflictos familiares, y el papel quejugaron algunos profesionales cubanos en esa importante misión,partiendo de las perspectivas que ofrece la creación de Centros de Mediación, los cuales ayudarán en las comunidades a la orientación y solución de diversos asuntos familiares y el rol desempeñado porlos trabajadores sociales. En el sistema jurídico cubano, en el ámbito familiar no se encuentra implementada la mediación, pero existe un grupo de profesionales que en su accionar diario desarrollan prácticas de mediación. Dentro de ese grupo es de interés resaltar al trabajador social quien como agentecomunitario tiene una enorme importancia, por su papel como verdadero consejero que ayuda dentro de la comunidad, a resolver los problemas sin necesidad de la intervención de la justicia estatal.
Technology, Production management. Operations management