Laser Cutting of Small Diameter Nitinol Tube

2012 ◽  
Vol 729 ◽  
pp. 460-463
Author(s):  
Péter Nagy ◽  
János Dobránszky

In this article the complex research and development project of the laser cutting micromachining of nitinol alloys are shown. The laser cutting parameters of the 1.04 mm inner diameter and 0.1 mm wall thickness nitinol tubes are also shown. The laser cutting parameters of micromachining and the cut surface of nitinol tubes are summarized when 3 mJ pulse energy, 0.02 ms pulse duration, 6 bar Ar gas pressure, 3000 Hz frequency, 10 mm/s rotation speed and 5 mm/s2 speed-up were used. The effect of the laser cutting to the raw material is characterized by microstructural and micromechanical examinations. A detailed description is given of the energy input by laser beam machining. The pulse and the impact of the applied pressure parameters of the gas to the raw material are also shown.

2015 ◽  
Vol 33 (4) ◽  
pp. 816-825 ◽  
Author(s):  
Jan Macioszczyk ◽  
Karol Malecha ◽  
Andrzej Stafiniak ◽  
Leszek J. Golonka

AbstractA great advantage of Low Temperature Co-fired Ceramics (LTCC) yields the possibility of channel and air cavity fabrication. Such empty spaces have numerous applications, for example, in microfluidics, microwave techniques and integrated packaging. However, improper geometry of these structures can degrade the performance of the final device. The processing parameters recommended by the LTCC tape supplier are relevant for the production of multilayer circuits but not surface embedded channels and/or cavities. Thus, it is important to examine which factors of the fabrication process are the most significant. In our study, special attention has been paid to the geometric performance of the channel structure resulting from the applied processing parameters. Laser cutting parameters were checked to obtain the structures with great fidelity. The impact of an isostatic lamination on the quality of the final structure was analyzed. The influence of pressure and temperature of the lamination process on the channel geometry and tape shrinkage were examined. The performed experiments showed that some improvements in channel/cavity geometry may be achieved by optimizing the processing procedures. The microscopic observations combined with the Analysis of Variance (ANOVA) showed which combinations of the processing parameters are the best for achieving a channel/cavity structure with the desired geometry.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 485
Author(s):  
Vera Schmid ◽  
Antje Trabert ◽  
Judith (Schäfer) Keller ◽  
Mirko Bunzel ◽  
Heike P. Karbstein ◽  
...  

Food by-products can be used as natural and sustainable food ingredients. However, a modification is needed to improve the technofunctional properties according to the specific needs of designated applications. A lab-scale twin-screw extruder was used to process enzymatically treated apple pomace from commercial fruit juice production. To vary the range of the thermomechanical treatment, various screw speeds (200, 600, 1000 min−1), and screw configurations were applied to the raw material. Detailed chemical and functional analyses were performed to develop a comprehensive understanding of the impact of the extrusion processing on apple pomace composition and technofunctional properties as well as structures of individual polymers. Extrusion at moderate thermomechanical conditions increased the water absorption, swelling, and viscosity of the material. An increase in thermomechanical stress resulted in a higher water solubility index, but negatively affected the water absorption index, viscosity, and swelling. Scanning electron microscopy showed an extrusion-processing-related disruption of the cell wall. Dietary fiber analysis revealed an increase of soluble dietary fiber from 12.6 to 17.2 g/100 g dry matter at maximum thermo-mechanical treatment. Dietary fiber polysaccharide analysis demonstrated compositional changes, mainly in the insoluble dietary fiber fraction. In short, pectin polysaccharides seem to be susceptible to thermo-mechanical stress, especially arabinans as neutral side chains of rhamnogalacturonan I.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 276
Author(s):  
Hang Jia ◽  
Haoxi Ben ◽  
Fengze Wu

Biochar is generally accepted and increasingly valued in scientific circles as solid products in the thermochemical conversion of biomass, mainly because of its rich carbon content. The purpose of this research is to investigate the impact of biochar from different sources on wheat growth. In particular, this work focused on the effect of different preparation methods and raw material of biochar on the growth of wheat and aim to find a potential soil substitute that can be used for crop cultivation. Two synthetic methods were evaluated: hydrothermal conversion and pyrolysis. The characterization of biochar was determined to explore the impact of its microstructure on wheat growth. The results show that the yield of biochar produced from high-pressure reactor is significantly higher than that obtained by using microwave reactor. For example, the biochar yield obtained through the former is about six times that of the latter when using steamed bread cooked as biomass raw material. In addition, the growth trend of wheat indicates that biochar has different promoting effects on the growth of wheat in its weight and height. The pyrolyzed carbon is more suitable for wheat growth and is even more effective than soil, indicating that pyrolyzed biochar has more potential to be an alternative soil in the future. Moreover, this research tries to explore the reasons that affect crop growth by characterizing biochar (including scanning electron microscopy (SEM), biofilm electrostatic test (BET) and Fourier transform infrared (FT-IR)). The results indicate that the biochar containing more pits and less hydroxyl functional are more suitable for storing moisture, which is one of the significant factors in the growth of crops. This study provides evidence of the effects of biochar on crop growth, both in terms of microstructure and macroscopic growth trends, which provides significant benefits for biochar to grow crops or plants.


Urban Science ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 54
Author(s):  
Yuejuan Yang ◽  
Hao Zhang ◽  
Xinquan Zhao ◽  
Zhizhang Chen ◽  
Aiguo Wang ◽  
...  

Ecosystem services are the material basis of economic and social development, and play essential roles in the sustainable development of ecosystems. Urbanization can remarkably alter the provision of ecosystem services. Most studies in this area have focused on densely populated metropolises with poor ecological environments, while comparatively few studies have focused on cities with low ecological pressures. Therefore, to avoid continuing to engage in the repetitive pattern of destroying first and rehabilitating later, quantitative analyses of urbanization and ecosystem services should be carried out in representative cities. In this study, based on partial least squares-discriminant analysis, kernel density estimation, and correlation analysis, we quantitatively evaluated the impact of urbanization on ecosystem services in Weifang city. The Data Center for Resources and Environmental Sciences at the Chinese Academy of Sciences and the Institute of Geographic Sciences and Natural Resources Research provided remote sensing data on land use, the gross domestic production (GDP), population data, and ecosystem services. The results were as follows: (1) The variation in population, GDP, and built-up areas consistently increased throughout the study period, whereas the ecosystem service values (ESVs) decreased; (2) food production, raw material production, nutrient cycle maintenance, and soil conservation were decisive ecosystem services that led to vast reductions in ESVs during the process of urbanization; and (3) the negative correlation coefficient between built-up areas and ecosystem services was greater than that between the population or GDP and ecosystem services, which indicated that the impacts of population and economic urbanization on ecosystem services lagged behind the impact of land urbanization. This study provides references for fully recognizing the ecological effects of urbanization, and make suggestions regarding the application of ecosystem services in sustainable development.


2020 ◽  
Vol 12 (24) ◽  
pp. 10454
Author(s):  
Katarína Teplická ◽  
Martin Straka

This article summarizes the arguments within the scientific discussion on the issue of using mining machines and their life cycle. The main goal of the article is to investigate the impact of a combination of mobile and stationary mining machines and their optimal distribution in the mining process to increase the efficiency of mining and processing of raw materials. The following methods of research were focused on the use of technical indicators for the valuation efficiency of the mining process: a simulation method was used for the distribution of mining machines, comparison analysis was used for the real and past state of mining machines, and a decision tree was used as managerial instrument for optimal alternatives of mining machines. The research empirically confirms and theoretically proves that optimal distribution of mining machines and machine parks is very important for mining companies. The benefit of this research for the mining company was the new location of the machines and the combination of stationary production lines and mobile equipment. The optimal layout of the machines reduced the number of conveyor belts and improved the transfer of limestone processing to mobile devices, saving time, which was reflected in transport costs. The results can be useful for other mining companies seeking to create an optimal machine park.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 447
Author(s):  
Miguel Alfonso Quiñones-Reveles ◽  
Víctor Manuel Ruiz-García ◽  
Sarai Ramos-Vargas ◽  
Benedicto Vargas-Larreta ◽  
Omar Masera-Cerutti ◽  
...  

This study aimed to evaluate and compare the relationship between chemical properties, energy efficiency, and emissions of wood and pellets from madroño Arbutus xalapensis Kunth, tázcate Juniperus deppeana Steud, and encino colorado Quercus sideroxyla Humb. & Bonpl. in two gasifiers (top-lit-up-draft (T-LUD) and electricity generation wood camp stove (EGWCS)) in order to determine the reduction of footprint carbon. In accordance with conventional methodologies, we determined the extracts and chemical components (lignin, cellulose, holocellulose), and the immediate analyses were carried out (volatile materials, fixed carbon, ash content and microanalysis of said ash), as well as the evaluation of emission factors (total suspended particulate matter (PM2.5), CO, CO2, CH4, black carbon (BC), elemental carbon (EC), and organic carbon (OC)). The results were statistically analyzed to compare each variable among species and gasifiers. The raw material analyzed showed how the pH ranged from 5.01 to 5.57, and the ash content ranged between 0.39 and 0.53%. The content values of Cu, Zn, Fe, Mg, and Ca ranged from 0.08 to 0.22, 0.18 to 0.19, 0.38 to 0.84, 1.75 to 1.90, and 3.62 to 3.74 mg kg−1, respectively. The extractive ranges from cyclohexane were 2.48–4.79%, acetone 2.42–4.08%, methanol 3.17–7.99%, and hot water 2.12–4.83%. The range of lignin was 18.08–28.60%. The cellulose content ranged from 43.30 to 53.90%, and holocellulose from 53.50 to 64.02%. The volatile material range was 81.2–87.42%, while fixed carbon was 11.30–17.48%; the higher heating value (HHV) of raw material and pellets presented the ranges 17.68–20.21 and 19.72–21.81 MJ kg−1, respectively. Thermal efficiency showed statistically significant differences (p < 0.05) between pellets and gasifiers, with an average of 31% Tier 3 in ISO (International Organization for Standardization) for the T-LUD and 14% (ISO Tier 1) for EGWCS, with Arbutus xalapensis being the species with the highest energy yield. The use of improved combustion devices, as well as that of selected raw material species, can reduce the impact of global warming by up to 33% on a cooking task compared to the three-stone burner.


Land ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Wojciech Bal ◽  
Magdalena Czalczynska-Podolska

The coastline of Western Pomerania has natural and cultural assets that have promoted the development of tourism, but also require additional measures to ensure the traditional features and characteristics are protected. This is to ensure that new developments conform to a more uniform set of spatial structures which are in line with the original culture. Today, seaside resorts are characterized by a rapid increase in development with a clear trend towards non-physiognomic architectural forms which continually expand and encroach on land closer to the coastline. This results in a blurring of the original concepts that characterized the founding seaside resort. This study evaluates 11 development projects (including a range of hotels, luxury residential buildings and hotel suites) built in 2009–2020 in the coastal area of Western Pomerania. An assessment of architecture-and-landscape integration for each development project was made, using four groups of evaluation criteria: aesthetic, socio-cultural, functional and locational factors. The study methodology included a historical and interpretative study (iconology, iconography, historiography) and an examination of architecture-and-landscape integration using a pre-prepared evaluation form. Each criterion was first assessed using both field surveys and desk research (including the analysis of construction plans and developer materials), and then compared with the original, traditional qualities of the town. This study demonstrates that it is possible to clearly identify the potential negative impact of tourism development on the cultural landscape of seaside resorts, and provides recommendations for future shaping, management and conservation of the landscape.


Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.


2018 ◽  
Vol 49 ◽  
pp. 02020
Author(s):  
Hery Suliantoro ◽  
Nurul Fitriani ◽  
Bagus Hario Setiadji

Risk is a condition caused by uncertainty. Risks will occur on any construction project, including bridge construction projects. Efforts that can be taken to minimize the impact of these risks are to engage in risk management activities. This research was conducted on bridge construction work on toll road procurement project in Pejagan-Pemalang, Pemalang-Batang and Salatiga-Kertasura. The purpose of this research is to analyze the risk of bridge development project in toll road project using Risk Breakdown Structure (RBS) method and then the result as database in discussing risk response strategy. The bridge construction project has 36 risks that are divided into six groups: materials and equipment, design, human resources, finance, management, nature and environmental conditions. Bad weather risks are the higest risk and seasonal risk causing temporary work stoppages. This risk-response strategy is avoidance. Short-term avoidance response strategy is to add shift workers, install tents and add additives in the acceleration of the process of maturation of concrete. The long-term avoidance response strategy is to evaluate and rearrange the work schedule by considering the weather forecast report.


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