scholarly journals Deployment and evaluation of a dual-sensor autofocusing method for on-machine measurement of patterns of small holes on freeform surfaces

2014 ◽  
Vol 53 (10) ◽  
pp. 2246
Author(s):  
Xiaomei Chen ◽  
Andrew Longstaff ◽  
Simon Fletcher ◽  
Alan Myers
Author(s):  
L. Andrew Staehelin

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.


2020 ◽  
Author(s):  
Ian Mallov ◽  
Fiona Jeeva ◽  
Chris Caputo

Food is often wasted due to real or perceived concerns about preservation and shelf life. Thus, precise, accurate and consumer-friendly methods of indicating whether food is safe for consumers are drawing great interest. The colorimetric sensing of biogenic amines released as food degrades is a potential way of determining the quality of the food. Herein, we report the use of genipin, a naturally occurring iridoid, as a dual colorimetric sensor for both oxygen and biogenic amines. Immobilization of genipin in edible calcium alginate beads demonstrates that it is a capable sensor for amine vapors and can be immobilized in a non-toxic, food-friendly matrix.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guilin Shan ◽  
Wolfgang Buescher ◽  
Christian Maack ◽  
André Lipski ◽  
Ismail-Hakki Acir ◽  
...  

AbstractHigh quality silage containing abundant lactic acid is a critical component of ruminant diets in many parts of the world. Silage deterioration, a result of aerobic metabolism (including utilization of lactic acid) during storage and feed-out, reduces the nutritional quality of the silage, and its acceptance by animals. In this study, we introduce a novel non-disruptive dual-sensor method that provides near real-time information on silage aerobic stability, and demonstrates for the first time that in situ silage temperature (Tsi) and pH are both associated with preservation of lactic acid. Aerobic deterioration was evaluated using two sources of maize silage, one treated with a biological additive, at incubation temperatures of 23 and 33 °C. Results showed a time delay between the rise of Tsi and that of pH following aerobic exposure at both incubation temperatures. A 11 to 25% loss of lactic acid occurred when Tsi reached 2 °C above ambient. In contrast, by the time the silage pH had exceeded its initial value by 0.5 units, over 60% of the lactic acid had been metabolized. Although pH is often used as a primary indicator of aerobic deterioration of maize silage, it is clear that Tsi was a more sensitive early indicator. However, the extent of the pH increase was an effective indicator of advanced spoilage and loss of lactic acid due to aerobic metabolism for maize silage.


2021 ◽  
pp. 095605992110338
Author(s):  
Saeid Haghir ◽  
Ramtin Haghnazar ◽  
Sara Saghafi Moghaddam ◽  
Danial Keramat ◽  
Mohammad Reza Matini ◽  
...  

Complex freeform surfaces and structures are increasingly designed and used in the product and building industry due to the advances in mathematics and digital design tools. However, there is still a gap between designing freeform surfaces and fabricating them. The process of preparing freeform surfaces’ shop drawings is complicated, time-consuming, and lacks the mutual understanding among the stakeholders. Computational design and Building Information Modeling (BIM) can serve as a mediator agent for the integration of design goals with the geometric logic of constructability. They can also facilitate creating platforms for designing and evaluating freeform structures. This open-ended qualitative research attempts to develop a systematic methodology for automating the design and construction drafting process of freeform lattice space structure. Solving this complex geometric problem aims to benefit the design for construction and manufacturers and shrink the cost and time of the process. The study employs a 3D computer-aided design (CAD) tool and introduces an algorithm that generates a BIM model. The BIM model contains shop drawings and suggests the specifications of the main elements, such as beams, glass panels, and nodes.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 828
Author(s):  
Zhaolong Li ◽  
Ye Dai

This paper presents a simulation and experimental study of the structure of small holes in GH4169 alloy electrolytic ally processed by tube electrodes with different characteristic power sources. It analyzes the multi-physical field coupling relationship of flow, temperature, and electric fields within the interstitial space. The results indicate that the tube electrode electrolytic processing of the GH4169 alloy small hole structure with a pulsed power supply has more uniform temperature and current density distribution within the gap, which is beneficial to the processing accuracy and smoothness of the small hole structure. Meanwhile, SEM was used to analyze the microscopic morphology of the electrode end surface during short-circuiting, and it was concluded that as the processing continued, the electrode end surface gradually produced a non-metallic oxide layer, which destroyed the electric field of the gap and affected the processing stability. The use of high-frequency positive and negative pulse power can effectively avoid the generation of a non-metallic oxide layer. Through the combination of simulation analysis and experimental verification, it is concluded that increasing electrolyte pressure in stages can effectively improve machining accuracy and stability. The interstitial current increases as the feed rate of the tool electrode increases, and the diameter of the machined small hole decreases as it increases.


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