Pulsed Laser-Based Hybrid Microscribing of Cu and Al in Salt Solution

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Sooraj Shiby ◽  
Nammi Srinagalakshmi ◽  
Nilesh J. Vasa ◽  
Shigeki Matsuo ◽  
Muralidhar Miryala

Abstract The influence of a subnanosecond pulsed laser-based scribing of copper (Cu) and aluminum (Al) in salt solutions (NaCl and KCl) on the formation of microchannels is reported. This technique allows laser scribing along with selective etching of Cu and Al thin films. The focused laser beam can elevate the surface temperature on the sample and hence the chemical reaction rate, resulting in combined ablation with selective-area etching. The depth of microchannels in Cu and Al films is increased by 3–5 μm using the proposed hybrid technique. The average surface roughness values in the microchannel are decreased compared to that of scribing in water and air. The hybrid approach of laser-based scribing combined with electrochemical etching in neutral salt solutions allows uniform channel with almost no redeposit layer and debris on the channel edges. Further, an approach wherein, an application of direct current (DC) voltage (1.2 V) between the tool and the workpiece while laser scribing of Cu and Al in salt solution was demonstrated to improve the channel depth by few micrometers. This hybrid machining technique has also resulted in a reduction in the surface oxidation near the laser-ablated zone compared to that observed in air and water-based experiments.

1958 ◽  
Vol 108 (2) ◽  
pp. 215-226 ◽  
Author(s):  
Jerome Gross

Precipitation (or gelation) of collagen from cold neutral salt solution induced by warming was shown to be reversible on subsequent cooling. The degree of reversibility of heat precipitation rapidly diminished with time of incubation at 37°C. For calf skin collagen (acetic acid-extracted) and guinea pig skin collagen (crude NaCl extract) in neutral salt solutions (Γ/2 = 0.45) roughly 90 per cent of newly formed gel redissolved on cooling at 2°C.; less than 20 per cent redissolved on cooling gels previously maintained at 37°C. for 24 hours. At physiologic ionic strength the same preparations exhibited much more rapid development of irreversible precipitation, but the same time dependence was clearly evident. Highly purified collagen from crude saline extracts of guinea pig skin exhibited the same phenomenon although the quantitative aspects were somewhat different.


Biochar ◽  
2021 ◽  
Author(s):  
Meng Wang ◽  
Negar D. Tafti ◽  
Jim J. Wang ◽  
Xudong Wang

AbstractRecent studies have shown that silicon (Si) dissolution from biochar may be influenced by the pyrolysis temperature. In addition, the enhancement of biochar by treatment with alkali has been proposed to produce a Si source that can be used for environmentally friendly plant disease control. In this study, biochars from rice straw and rice husk pretreated with KOH, CaO and K2CO3 and then pyrolyzed at 350, 450 and 550 °C were prepared to evaluate the effects of pyrolysis temperature on Si release and plant uptake from alkali-enhanced Si-rich biochar. Extractable Si and dissolution Si from the prepared biochars were assessed by different short-term chemical methods and long-term (30-day) release in dilute acid and neutral salt solutions, respectively, along with a rice potting experiment in greenhouse. For both rice straw- and husk-derived alkali-enhanced biochars (RS-10KB and HS-10K2B, respectively), increasing the pyrolysis temperature from 350 to 550 °C generally had the highest extractable Si and increased Si content extracted by 5-day sodium carbonate and ammonium nitrate (5dSCAN) designated for fertilizer Si by 61–142%, whereas non-enhanced biochars had more extractable Si at 350 °C. The alkali-enhanced biochars produced at 550 °C pyrolysis temperature also released 82–172% and 27–79% more Si than that of 350 °C produced biochar in unbuffered weak acid and neutral salt solutions, respectively, over 30 days. In addition, alkali-enhanced biochars, especially that derived from rice husk at 550 °C facilitated 6–21% greater Si uptake by rice and 44–101% higher rice grain yields than lower temperature biochars, non-enhanced biochars, or conventional Si fertilizers (wollastonite and silicate calcium slag). Overall, this study demonstrated that 550 °C is more efficient than lower pyrolysis temperature for preparing alkali-enhanced biochar to improve Si release for plant growth.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Masahiro Yanagiya ◽  
Noriko Hiyama ◽  
Jun Matsumoto

Abstract Background Various approaches have been used to assist and facilitate segmentectomy with favorable oncological outcomes. We describe a hybrid approach comprising virtual-assisted lung mapping (VAL-MAP), which is a preoperative bronchoscopic dye-marking technique, combined with systemic indocyanine green (ICG) injection. Clinical presentation An asymptomatic 64-year-old man was referred to our department because of a lung nodule detected during his annual medical checkup. The chest computed-tomography image revealed a 16-mm, partly solid, ground-glass nodule in the left segment 4. Because the nodule was hardly palpable and deeply located between the left upper division segment and the left lingular segment, we performed VAL-MAP to facilitate extended left lingulectomy. Five dye markings were undertaken preoperatively. Surgery to remove the nodule was then conducted via complete three-port video-assisted thoracic surgery. The VAL-MAP markings were easily identified intraoperatively and helped locate the nodule. The intersegmental plane was identified by the ICG injection. The resection line was determined based on the intersegmental plane identified by the ICG injection and the site of the nodule suggested by the VAL-MAP markings. Following the resection line, we thoracoscopically achieved extended lingulectomy with sufficient surgical margins. The patient was discharged with no complications. The pathological diagnosis was adenocarcinoma in situ. Conclusion The hybrid technique of VAL-MAP and systemic ICG injection can be useful for accomplishing successful extended segmentectomy.


2007 ◽  
Vol 539-543 ◽  
pp. 3807-3813 ◽  
Author(s):  
Paul S. Prevey ◽  
Douglas J. Hornbach ◽  
N. Jayaraman

Friction stir welding (FSW) allows the joining of aluminum alloys in ways previously unattainable offering new manufacturing technology. Friction stir processing (FSP) of cast alloys such as Ni-Al bronze eliminates casting voids and improves the properties to that of wrought material. However, the local heating produced by both FSW and FSP can leave a fusion zone with reduced mechanical properties and a heat-affected zone with tensile residual stresses that can be deleterious to fatigue performance. Controlled plasticity burnishing (CPB) is an established surface treatment technology that has been investigated and described extensively for the improvement of damage tolerance, corrosion fatigue, and stress corrosion cracking performance in a variety of alloys. Mechanical CPB processing in conventional CNC machine tools or with robotic tool positioning is readily adapted to industrial FSW and FSP fabrication of components, either simultaneously or as a post process. CPB was applied to FSP Ni-Al Bronze to produce a depth of compression of 2.5 mm and a maximum subsurface magnitude of –150 ksi. The effect of FSP on the fatigue performance in a saltwater marine environment and in the presence of foreign object damage (FOD) was documented with and without CPB processing. FSP was found to increase the fatigue strength of the Ni-Al Bronze by 70% without affecting the corrosion behavior of neutral salt solution. FSW actually produced a more noble material in the acidic salt solution. CPB after FSP mitigated damage 1 mm deep.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Konrad Rolle ◽  
Dmytro Yaremkevich ◽  
Alexey V. Scherbakov ◽  
Manfred Bayer ◽  
George Fytas

AbstractHypersonic phononic bandgap structures confine acoustic vibrations whose wavelength is commensurate with that of light, and have been studied using either time- or frequency-domain optical spectroscopy. Pulsed pump-probe lasers are the preferred instruments for characterizing periodic multilayer stacks from common vacuum deposition techniques, but the detection mechanism requires the injected sound wave to maintain coherence during propagation. Beyond acoustic Bragg mirrors, frequency-domain studies using a tandem Fabry–Perot interferometer (TFPI) find dispersions of two- and three-dimensional phononic crystals (PnCs) even for highly disordered samples, but with the caveat that PnCs must be transparent. Here, we demonstrate a hybrid technique for overcoming the limitations that time- and frequency-domain approaches exhibit separately. Accordingly, we inject coherent phonons into a non-transparent PnC using a pulsed laser and acquire the acoustic transmission spectrum on a TFPI, where pumped appear alongside spontaneously excited (i.e. incoherent) phonons. Choosing a metallic Bragg mirror for illustration, we determine the bandgap and compare with conventional time-domain spectroscopy, finding resolution of the hybrid approach to match that of a state-of-the-art asynchronous optical sampling setup. Thus, the hybrid pump–probe technique retains key performance features of the established one and going forward will likely be preferred for disordered samples.


Biopolymers ◽  
1971 ◽  
Vol 10 (1) ◽  
pp. 47-68 ◽  
Author(s):  
Dieter W. Gruenwedel ◽  
Chi-Hsia Hsu ◽  
Don S. Lu

Biopolymers ◽  
1971 ◽  
Vol 10 (6) ◽  
pp. 1103-1103
Author(s):  
Dieter W. Gruenwedel ◽  
Cih-Hsia Hsu ◽  
Don S. Lu

1958 ◽  
Vol 107 (2) ◽  
pp. 265-277 ◽  
Author(s):  
Jerome Gross

The total amount of neutral salt-extractible collagen in the skin of growing, suckling guinea pigs amounted to about 10 per cent of the total collagen of the dennis. This is roughly equivalent to a 1 to 2 day increment in dermal collagen incident to growth. Fourteen days of static weight maintained by limited caloric intake reduced the neutral salt-extractible collagen to very low levels. Following this period, 5 to 7 days of steady weight gain induced by ad lib. feeding was required to produce significant increases in this collagen fraction. Return to control levels occurred within 12 days of continuous growth. The amount of collagen extracted from the dermis of young guinea pigs with cold neutral salt solutions varied directly with growth rate (weight gain) and was greatly diminished after short periods of restricted caloric intake. Two days of fasting diminished the total extracted collagen by one-half. Three consecutive extractions with citrate buffer pH, 3.5, of the residues remaining after exhaustive saline extraction removed 40 per cent more collagen from the skins of actively growing animals than from those of animals fasted for 2 days. However, subsequent extraction of residues with dilute acetic acid equalized the total amount of collagen extracted at acid pH from the two groups. The viscosity of cold neutral extracts was unrelated to the concentrations of non-collagenous proteins and carbohydrates but varied directly with the collagen content.


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