Substantial Improvement of Oil Aerosol Filtration Performance Using In-Plane Asymmetric Wettability

2020 ◽  
Vol 12 (25) ◽  
pp. 28852-28860
Author(s):  
Xin Wei ◽  
Yufeng Liu ◽  
Hua Zhou ◽  
Feng Chen ◽  
Hongxia Wang ◽  
...  
Author(s):  
Dae Hoon Park ◽  
Jisoo Choi ◽  
Amin Piri ◽  
Jungho Hwang ◽  
Jeong Hoon Byeon

Safe-by-design concepts for anticoronaviral functions are important in the production of air filters, face masks, and touch substrates because these interventions may be effective in allowing continued socioeconomic activity and...


2019 ◽  
Vol 20 (2) ◽  
pp. 95
Author(s):  
Abdul Rajak ◽  
Tri Siswandi Syahputra ◽  
Muhammad Miftahul Munir ◽  
K. Khairurrijal

Since a nanofiber medium on itself is soft and fragile and cannot be used alone as air filters. Coating nanofiber on a rigid substrate to form a composite that can be handled readily is necessary. Beside can improve the filtration efficiency, adding the substrate will also save the use of nanofibers mat itself. The aim of this study is to evaluate the effect of substrate thickness on the performance of nanofibers mat in aerosol filtration in order to find the optimum thickness of substrate that can increase the quality of nanofiber filter. The substrate used was a low cost microfiber non-woven fabric made from polypropylene (PP). The nanofibers mat was composed of electrospun polyacrylonitrile (PAN) with concentration of 9 wt.% which dissolved at N,N dimethylformamide (DMF). Five variations of PP different in thickness was used as substrate. From the SEM image, it was found that there is increasing fiber diameter of PAN after electrospun into PP substrate. From the porosity estimation of each nanofiber, it was found that the porosity decreased with increasing the substrate thickness. For test the performance of nanofiber filter, the particles of polystyrene latex (PSL) which generated by atomizer was used as the aerosol particle. In addition, to evaluate the performance filter in PM2.5 filtration, the experiment was carried out with generate the smoke from burning incense. Air filtration performance of all variations is obtained by comparison the results of measurement including: pressure drop, efficiency and quality factor. From the results, there is limitation on the substrates thickness based on the value of the quality factor obtained. Overall, PP nonwoven as the substrates gives the great contribution on the efficiency of PAN nanofiber. Keywords: substrate, polypropylene, thickness, nanofiber, air filtration.


Author(s):  
B. K. Kirchoff ◽  
L.F. Allard ◽  
W.C. Bigelow

In attempting to use the SEM to investigate the transition from the vegetative to the floral state in oat (Avena sativa L.) it was discovered that the procedures of fixation and critical point drying (CPD), and fresh tissue examination of the specimens gave unsatisfactory results. In most cases, by using these techniques, cells of the tissue were collapsed or otherwise visibly distorted. Figure 1 shows the results of fixation with 4.5% formaldehyde-gluteraldehyde followed by CPD. Almost all cellular detail has been obscured by the resulting shrinkage distortions. The larger cracks seen on the left of the picture may be due to dissection damage, rather than CPD. The results of observation of fresh tissue are seen in Fig. 2. Although there is a substantial improvement over CPD, some cell collapse still occurs.Due to these difficulties, it was decided to experiment with cold stage techniques. The specimens to be observed were dissected out and attached to the sample stub using a carbon based conductive paint in acetone.


2000 ◽  
Vol 20 (03) ◽  
pp. 136-142 ◽  
Author(s):  
D. L. Ornstein ◽  
L. R. Zacharski

SummaryIt is widely known that the systemic blood coagulation mechanism is often activated in malignancy, leading to an increased incidence of vascular thromboses in patients with cancer. It is not widely appreciated, however, that products of the coagulation mechanism may also support tumor growth and dissemination. Interest in this approach to cancer therapy has surged recently because of mounting evidence that the familiar anticoagulant drug, heparin, may impede tumor progression. Heparin has the capacity to modify angiogenesis, growth factor and protease activity, immune function, cell proliferation and gene expression in ways that may block malignant dissemination. Clinical trials in which heparin has been administered to a broad spectrum of patients to prevent or treat thrombosis have unexpectedly shown improvement in survival in the subset of patients with malignancy entered to these studies. Meta-analyses of clinical trials comparing unfractionated (UF) versus low molecular weight (LMW) heparin treating venous thromboembolism suggest that there may be substantial improvement in cancer outcome in patients with malignancy randomized to receive LMW heparin. These findings provide a rationale for definitive clinical trials of LMW heparin in cancer, and the results of several such studies that are currently underway are awaited with interest.


2002 ◽  
Vol 722 ◽  
Author(s):  
Ram W. Sabnis ◽  
Mary J. Spencer ◽  
Douglas J. Guerrero

AbstractNovel organic, polymeric materials and processes of depositing thin films on electronics substrates by chemical vapor deposition (CVD) have been developed and the lithographic behavior of photoresist coated over these CVD films at deep ultraviolet (DUV) wavelength has been evaluated. The specific monomers synthesized for DUV applications include [2.2](1,4)- naphthalenophane, [2.2](9,10)-anthracenophane and their derivatives which showed remarkable film uniformity on flat wafers and conformality over structured topography wafers, upon polymerization by CVD. The chemical, physical and optical properties of the deposited films have been characterized by measuring parameters such as thickness uniformity, solubility, conformality, adhesion to semiconductor substrates, ultraviolet-visible spectra, optical density, optical constants, defectivity, and resist compatibility. Scanning electron microscope (SEM) photos of cross-sectioned patterned wafers showed verticle profiles with no footing, standing waves or undercut. Resist profiles down to 0.10 νm dense lines and 0.09 νm isolated lines were achieved in initial tests. CVD coatings generated 96-100% conformal films, which is a substantial improvement over commercial spin-on polymeric systems. The light absorbing layers have high optical density at 248 nm and are therefore capable materials for DUV lithography applications. CVD is a potentially useful technology to extend lithography for sub-0.15 νm devices. These films have potential applications in microelectronics, optoelectronics and photonics.


Author(s):  
Golokesh Santra ◽  
Nitai Sylvetsky ◽  
Gershom Martin

We present a family of minimally empirical double-hybrid DFT functionals parametrized against the very large and diverse GMTKN55 benchmark. The very recently proposed wB97M(2) empirical double hybrid (with 16 empirical parameters) has the lowest WTMAD2 (weighted mean absolute deviation over GMTKN55) ever reported at 2.19 kcal/mol. However, our xrevDSD-PBEP86-D4 functional reaches a statistically equivalent WTMAD2=2.22 kcal/mol, using just a handful of empirical parameters, and the xrevDOD-PBEP86-D4 functional reaches 2.25 kcal/mol with just opposite-spin MP2 correlation, making it amenable to reduced-scaling algorithms. In general, the D4 empirical dispersion correction is clearly superior to D3BJ. If one eschews dispersion corrections of any kind, noDispSD-SCAN offers a viable alternative. Parametrization over the entire GMTKN55 dataset yields substantial improvement over the small training set previously employed in the DSD papers.


2019 ◽  
Author(s):  
Golokesh Santra ◽  
Nitai Sylvetsky ◽  
Gershom Martin

We present a family of minimally empirical double-hybrid DFT functionals parametrized against the very large and diverse GMTKN55 benchmark. The very recently proposed wB97M(2) empirical double hybrid (with 16 empirical parameters) has the lowest WTMAD2 (weighted mean absolute deviation over GMTKN55) ever reported at 2.19 kcal/mol. However, our xrevDSD-PBEP86-D4 functional reaches a statistically equivalent WTMAD2=2.22 kcal/mol, using just a handful of empirical parameters, and the xrevDOD-PBEP86-D4 functional reaches 2.25 kcal/mol with just opposite-spin MP2 correlation, making it amenable to reduced-scaling algorithms. In general, the D4 empirical dispersion correction is clearly superior to D3BJ. If one eschews dispersion corrections of any kind, noDispSD-SCAN offers a viable alternative. Parametrization over the entire GMTKN55 dataset yields substantial improvement over the small training set previously employed in the DSD papers.


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