scholarly journals Automated SEM Image Analysis of the Sphere Diameter, Sphere-Sphere Separation, and Opening Size Distributions of Nanosphere Lithography Masks

2021 ◽  
pp. 1-11
Author(s):  
Thomas Riedl ◽  
Jörg K.N. Lindner
Keyword(s):  
Detection Efficiency ◽  
Size Variation ◽  
Cost Effective ◽  
Automated Analysis ◽  
Sphere Diameter ◽  
Size Distributions ◽  
Sem Images ◽  
Detection Techniques ◽  
Sem Image ◽  
Sphere Size

Abstract Colloidal nanosphere monolayers—used as a lithography mask for site-controlled material deposition or removal—offer the possibility of cost-effective patterning of large surface areas. In the present study, an automated analysis of scanning electron microscopy (SEM) images is described, which enables the recognition of the individual nanospheres in densely packed monolayers in order to perform a statistical quantification of the sphere size, mask opening size, and sphere-sphere separation distributions. Search algorithms based on Fourier transformation, cross-correlation, multiple-angle intensity profiling, and sphere edge point detection techniques allow for a sphere detection efficiency of at least 99.8%, even in the case of considerable sphere size variations. While the sphere positions and diameters are determined by fitting circles to the spheres edge points, the openings between sphere triples are detected by intensity thresholding. For the analyzed polystyrene sphere monolayers with sphere sizes between 220 and 600 nm and a diameter spread of around 3% coefficients of variation of 6.8–8.1% for the opening size are found. By correlating the mentioned size distributions, it is shown that, in this case, the dominant contribution to the opening size variation stems from nanometer-scale positional variations of the spheres.

A View Of Macro-Defect-Free (MDF) Pastes

1989 ◽  
Vol 179 ◽  
Author(s):  
M. R. Silsbee ◽  
D. M. Roy ◽  
M. Perez-Pena
Keyword(s):  
Pore Size ◽  
Automated Analysis ◽  
Size Distributions ◽  
Sem Images ◽  
Portland Cements ◽  
Pore Size Distributions

AbstractThe automated analysis of backscattered SEM images from polished surfaces of macro-defect-free cements based on ordinary portland cements is examined. A comparison of several techniques for the determination of pore size distributions in these materials is made.

scholarly journals Advances in Environmental Detection and Clinical Diagnostic Tests for Legionella Species

2021 ◽  
Author(s):  
Rajeshwari Vittal ◽  
Juliet Roshini Mohan Raj ◽  
Ballamoole Krishna Kumar ◽  
Indrani Karunasagar
Keyword(s):  
Developing Countries ◽  
Healthcare System ◽  
Diagnostic Tests ◽  
Clinical Manifestations ◽  
Cost Effective ◽  
Clinical Samples ◽  
Detection Techniques ◽  
Conventional Culture ◽  
Legionella Species ◽  
Mild Fever

Abstract Legionella is a fastidious organism that is difficult to culture in the lab but is widely distributed in environmental, domestic, and hospital settings. The clinical manifestations due to Legionella infections range from mild fever to fatal pneumonia and multiorgan pathologies. Legionella outbreaks though prevalent globally are not reported in developing countries due to difficulties in isolating this organism and the lack of simple diagnostic protocols. Here, we review the literature from across countries to present various methods used to detect Legionella from environmental and clinical samples. We compare the sensitivity and the specificity of the conventional culture-based assays with the recent methods and discuss approaches to develop better detection and diagnostic tests. With better cost-effective detection techniques and regular monitoring of the susceptible sites, which may harbor Legionella colonies, most of the Legionella infections can be prevented. As a result, considerable burden, caused by Legionella infections, on the healthcare system, in especially economically weaker countries, can be mitigated.

scholarly journals Development of Biochars Derived from Water Bamboo (Zizania latifolia) Shoot Husks Using Pyrolysis and Ultrasound-Assisted Pyrolysis for the Treatment of Reactive Black 5 (RB5) in Wastewater

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1615
Author(s):  
Thanh Tam Nguyen ◽  
Hung-Hsiang Chen ◽  
Thi Hien To ◽  
Yu-Chen Chang ◽  
Cheng-Kuo Tsai ◽  
...  
Keyword(s):  
Cost Effective ◽  
Reactive Black 5 ◽  
Order Kinetic ◽  
Sem Images ◽  
Zizania Latifolia ◽  
Surface Areas ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ultrasound Assisted ◽  
Green Technique

Adsorbent made by carbonization of biomass under oxygen-limited conditions has become a promising material for wastewater treatment owing to its cost-effective, simple, and eco-friendly processing method. Ultrasound is considered a green technique to modify carbon materials because it uses water as the solvent. In this study, a comparison of Reactive Black 5 (RB5) adsorption capacity between biochar (BC) generated by pyrolysis of water bamboo (Zizania latifolia) husks at 600 °C and ultrasound-assisted biochar (UBC) produced by pyrolysis at 600 °C assisted by ultrasonic irradiation was performed. UBC showed a greater reaction rate and reached about 80% removal efficiency after 4 h, while it took 24 h for BC to reach that level. Scanning electron microscope (SEM) images indicated that the UBC morphology surface was more porous, with the structure of the combination of denser mesopores enhancing physiochemical properties of UBC. By Brunauer, Emmett, and Teller (BET), the specific surface areas of adsorbent materials were analyzed, and the surface areas of BC and UBC were 56.296 m2/g and 141.213 m2/g, respectively. Moreover, the pore volume of UBC was 0.039 cm3/g, which was higher than that of BC at 0.013 cm3/g. The adsorption isotherms and kinetics revealed the better fits of reactions to Langmuir isotherm and pseudo-second-order kinetic model, indicating the inclination towards monolayer adsorption and chemisorption of RB5 on water bamboo husk-based UBC.

scholarly journals Electrochemical Biosensors for Cytokine Profiling: Recent Advancements and Possibilities in the Near Future

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 94
Author(s):  
Nirmita Dutta ◽  
Peter B. Lillehoj ◽  
Pedro Estrela ◽  
Gorachand Dutta
Keyword(s):  
Immune System ◽  
Cost Effective ◽  
Anomalous Behavior ◽  
Quantitative Detection ◽  
Electrochemical Biosensors ◽  
Aberrant Expression ◽  
Detection Techniques ◽  
Short Period ◽  
User Friendly ◽  
Cytokine Profiling

Cytokines are soluble proteins secreted by immune cells that act as molecular messengers relaying instructions and mediating various functions performed by the cellular counterparts of the immune system, by means of a synchronized cascade of signaling pathways. Aberrant expression of cytokines can be indicative of anomalous behavior of the immunoregulatory system, as seen in various illnesses and conditions, such as cancer, autoimmunity, neurodegeneration and other physiological disorders. Cancer and autoimmune diseases are particularly adept at developing mechanisms to escape and modulate the immune system checkpoints, reflected by an altered cytokine profile. Cytokine profiling can provide valuable information for diagnosing such diseases and monitoring their progression, as well as assessing the efficacy of immunotherapeutic regiments. Toward this goal, there has been immense interest in the development of ultrasensitive quantitative detection techniques for cytokines, which involves technologies from various scientific disciplines, such as immunology, electrochemistry, photometry, nanotechnology and electronics. This review focusses on one aspect of this collective effort: electrochemical biosensors. Among the various types of biosensors available, electrochemical biosensors are one of the most reliable, user-friendly, easy to manufacture, cost-effective and versatile technologies that can yield results within a short period of time, making it extremely promising for routine clinical testing.

scholarly journals Effects of Synthetic Procedures and Postsynthesis Incubation pH on Size, Shape, and Antibacterial Activity of Copper (I) Oxide Nanoparticles

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Vinh Tien Nguyen ◽  
Khanh Son Trinh
Keyword(s):  
Antibacterial Activity ◽  
High Surface ◽  
Size Variation ◽  
Reaction Rates ◽  
Bacterial Suspension ◽  
Oxide Nanoparticles ◽  
Surface Charges ◽  
Fast Reaction ◽  
Sem Images ◽  
Etching Effect

Copper (I) oxide nanoparticles (Cu2O NP) were synthesized by reducing CuSO4 with glucose in the presence of polyvinyl alcohol as a capping agent. We used three different synthetic procedures with a fast reaction (procedure 1p), a fast-then-slow reaction (procedure 2p), and a slow-then-fast reaction (procedure 3p). The reaction rates were controlled by changing the temperature and the speed of adding reagents. The synthesized Cu2O NP were subsequently incubated for 24 h in a pH 6 solution (Cu2O NP6) or a pH 8 solution (Cu2O NP8) at 5°C. XRD and SEM images analysis revealed that the 1p procedure produced smaller NP, while the 2p procedure produced larger but more uniform NP. The 3p procedure produced the largest NP with a higher size variation. The 24-hour acidic postsynthesis incubation resulted in an etching effect, which reduced the size and size variation of Cu2O NP6. To evaluate the antibacterial activity, E. coli suspensions were mixed with the obtained Cu2O NP (32, 96, or 160 ppm) for different time intervals (1 or 24 h) and then grown on Petri dishes at 37°C for 24 h. Higher doses, smaller sizes of Cu2O NP, and longer contact times with the bacterial suspension resulted in higher inactivation efficiencies. Cu2O NP6 showed higher antibacterial effects at low doses, possibly due to the etching effect and the positive surface charge. Increasing the Cu2O doses from 32 to 96 and 160 ppm noticeably increased the antibacterial effect of the Cu2O NP8, but not significantly for Cu2O NP6. We suggested that the Cu2O NP6 suffered from agglomeration at high doses due to their high surface activity and low surface charges.

Electrophoretic Deposition of 10B Nano/Micro Particles in Deep Silicon Trenches for the Fabrication of Solid State Thermal Neutron Detectors

2018 ◽  
Vol 27 (01n02) ◽  
pp. 1840002 ◽  
Author(s):  
Machhindra Koirala ◽  
Jia Woei Wu ◽  
Adam Weltz ◽  
Rajendra Dahal ◽  
Yaron Danon ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Neutron ◽  
Electrophoretic Deposition ◽  
Detection Efficiency ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Deposition Process ◽  
Neutron Detectors ◽  
Micro Particles ◽  
Silicon Trenches

We present a cost effective and scalable approach to fabricate solid state thermal neutron detectors. Electrophoretic deposition technique is used to fill deep silicon trenches with 10B nanoparticles instead of conventional chemical vapor deposition process. Deep silicon trenches with width of 5-6 μm and depth of 60-65 μm were fabricated in a p-type Si (110) wafer using wet chemical etching method instead of DRIE method. These silicon trenches were converted into continuous p-n junction by the standard phosphorus diffusion process. 10B micro/nano particle suspension in ethyl alcohol was used for electrophoretic deposition of particles in deep trenches and iodine was used to change the zeta potential of the particles. The measured effective boron nanoparticles density inside the trenches was estimated to be 0.7 gm cm-3. Under the self-biased condition, the fabricated device showed the intrinsic thermal neutron detection efficiency of 20.9% for a 2.5 × 2.5 mm2 device area.

Graphene Oxide as a Substrate for Biosensors: Synthesis and Characterization

2021 ◽  
Vol 324 ◽  
pp. 87-93
Author(s):  
Mohamed Adel ◽  
Abdel Hady A. Abdel-Wahab ◽  
Ahmed Abdel-Mawgood ◽  
Ahmed Osman Egiza
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Acidic Solution ◽  
Cost Effective ◽  
Sem Analysis ◽  
Visible Spectroscopy ◽  
Sem Images ◽  
Hummers Method ◽  
Uv Visible ◽  
Modified Hummers Method

Graphene oxide (GO) is an oxidized nanosheets of graphite with a 2D planar structure. GO could be readily complexed with bio-entities as it possesses many oxygen-containing functionalities on its surface. The preparation process is fast, easy, and cost-effective. It was prepared using modified Hummers’ method in acidic solution as a primary solvent and potassium permanganate as an oxidizing agent. Afterwards, it was successfully characterized by FTIR, UV-visible spectroscopy, as well as XRD and Raman spectroscopy, and finally, SEM analysis. It was observed that the formed GO is mainly composed of carbon and oxygen elements rich in oxygen functional groups. Furthermore, the existence of (001) plane in XRD interprets the complete oxidation of graphite with d-spacing 9 Å. Moreover, Raman spectroscopy displayed the sp3 carbon hybridization, besides, the ID/IG ratio is found to be 0.84, which confirms the disorder between graphene oxide layers. The SEM images also pointed out that graphene oxide sheets were regularly stacked together as flake-like structures. Accordingly, the richness of oxygen-containing functionalities was confirmed. Hence, it is appropriate to be used as a base transducer for biosensing applications.

Research of Coal Pores and Integrity Evaluation Method Based on Fractal Theory

2014 ◽  
Vol 670-671 ◽  
pp. 258-262 ◽  
Author(s):  
Ji Li ◽  
Xin Wu
Keyword(s):  
Fractal Dimension ◽  
Coal Sample ◽  
Evaluation Method ◽  
Structural Integrity ◽  
Gas Adsorption ◽  
Fractal Theory ◽  
Physical And Mechanical Properties ◽  
Box Dimension ◽  
Sem Images ◽  
Sem Image

Coal is a natural porous media, its porosity and structural integrity influenced the gas adsorption and desorption characteristics greatly, as well as physical and mechanical properties of coal. Scanning electron microscopy (SEM) is applied to acquire SEM image of four kinds of coal samples at different zoom levels, and the box dimension can be worked out based on the pore preprocessing of SEM images. Then, the numerical value of box dimension is used to describe the development degree of the four kinds of coal sample and four development degrees’ sequence. At last, the intrinsic relevance between fractal dimension and other parameters is analyzed through mathematic method. The results show as follows: coal sample has self-similarity characteristic; the fractal dimension is related to both the total number of pores and porosity degree; the data of the coal pore, analyzed through fractal dimension, are consistent with that through traditional method; what’s more, fractal dimension has more advantages in describing accuracy and simplicity.

Assessment of harvest blocks generated from operational polygons and forest-cover polygons in tactical and strategic planning

2001 ◽  
Vol 31 (4) ◽  
pp. 682-693 ◽  
Author(s):  
John Nelson
Keyword(s):  
Strategic Planning ◽  
Landscape Structure ◽  
Forest Cover ◽  
Block Size ◽  
Cost Effective ◽  
Size Distributions ◽  
Strategic Plans ◽  
Important Barrier ◽  
Interior Forest ◽  
Block Size Distribution

Manually designing harvest units for strategic planning is expensive. This paper compares blocking methods based on forest-cover polygons and manually designed harvest units. Routines are used to split and aggregate polygons into three block size distributions: (i) uniform 40-ha blocks; (ii) uniform 120-ha blocks; and (iii) by area, one-third 20 ha, one-third 60 ha, and one-third 150 ha. Three harvest rules that influence adjacency and the cutting of polygons within a block are applied to each block size distribution to compare forecasts generated by forest-cover and operational blocks. Generally, volume flows from the two methods deviate by less than 5%, and the highest deviations usually occur during the first 20 years. Projected landscape structure, as measured by interior forest area, is also similar under the two blocking methods. The results indicate that forest-cover data provide a reasonable alternative to manual blocking in tactical and strategic plans. This is significant because it removes an important barrier to timely and cost-effective planning, especially for large geographic problems where manual blocking is not an option.

scholarly journals Annealing-Induced Modifications in Physicochemical and Optoelectronic Properties of Ag-Doped Nanostructured CdS Thin Films

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Vidya S. Taur ◽  
Rajesh A. Joshi ◽  
Ramphal Sharma
Keyword(s):  
Thin Films ◽  
Annealing Treatment ◽  
Cost Effective ◽  
Peak Position ◽  
Optoelectronic Properties ◽  
Sem Images ◽  
X Ray ◽  
Optical Absorbance ◽  
Air Atmosphere ◽  
Cds Thin Films

The Ag-doped nanostructured CdS thin films are grown by simple, cost effective chemical ion exchange technique at room temperature on ITO-coated glass substrate. These as grown thin films are annealed at 100, 200, 300, and 400°C in air atmosphere for 1 hour. To study the effect of annealing on physicochemical and optoelectronic properties, these as grown and annealed thin films are characterized for structural, compositional, morphological, optical, and electrical properties. X-ray diffraction (XRD) pattern reveals polycrystalline nature of these thin films with increase in crystallite size from 6.4 to 11.2 nm, from XRD the direct identification of Ag doping in CdS thin films cannot be judged, while shift in characteristics peak position of CdS is observed. The Raman spectrum represents increase in full width at half maxima and intensity of characteristic peak, confirming the material modification upon annealing treatment. Presence of Cd, Ag, and S in energy dispersive X-ray analysis spectra (EDAX) confirms expected elemental composition in thin films. Scanning electron microscopy (SEM) images represent grain growth and agglomeration upon annealing. Red shift in optical absorbance strength and energy band gap values from 2.28 to 2.14 eV is obtained.I-Vresponse obtained from as grown and annealed thin films shows an enhancement in photosensitivity from 72% to 96% upon illumination to 100 mW/cm2light source.

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