scholarly journals Improvement of the Efficiency of Perennial Seed Mixtures Separation on a Drum Vibro Electric Separator

2018 ◽  
Vol 66 (5) ◽  
pp. 1157-1164
Author(s):  
Stepan Kovalyshyn ◽  
Oleksanda Kovalyshyn
Keyword(s):  
Electrical Properties ◽  
Electric Field ◽  
Corona Discharge ◽  
Oscillation Frequency ◽  
Perennial Grasses ◽  
High Quality ◽  
Original Mixture ◽  
The Difference ◽  
Seed Mixtures

Separation of seed mixtures plays a very important role in obtaining high‑quality seeds, which is characterized by the absence of hard‑to‑separate admixtures of weeds. The aim of the work was to improve the quality of seed mixtures of perennial grasses due to the use of the drum separator in the process of their additional cleaning. The conducted studies determined the basic geometric dimensions of the components of seed mixtures of perennial grasses and their coefficients of friction on various materials. The difference in their values was insignificant, as a result of which it was found that separating by these indicators is inappropriate. We can intensify the separation of the studied mixtures by using a drum vibro electric separator, where the separation takes place in a combination of frictional and electrical properties of the components. The main adjustable parameters of vibro electric separation established by previous studies were: the drum speed f = 8 rpn; the electric field of corona discharge E = 3.0 kV/cm; the oscillation frequency of the drum f1 = 50 Hz; drum amplitude A = 1,6 mm. With such parameters of separation we achieved the purity of the seed of the clover and the timothy grass in the range of 97…98 %, which, respectively, for 22.5 % and 17.5 % exceeds the purity of the original mixture.

scholarly journals Enhancement of Satellite Imagesusing Image Sharpening Technique

2019 ◽  
Vol 8 (6S2) ◽  
pp. 351-354
Keyword(s):  
Image Processing ◽  
Color Image ◽  
Histogram Equalization ◽  
Grayscale Image ◽  
Original Image ◽  
High Quality ◽  
Wide Range ◽  
Equalization Technique ◽  
The Difference

In many image processing applications, a wide range of image enhancement techniques are being proposed. Many of these techniques demanda lot of critical and advance steps, but the resultingimage perception is not satisfactory. This paper proposes a novel sharpening method which is being experimented with additional steps. In the first step, the color image is transformed into grayscale image, then edge detection process is applied using Laplacian technique. Then deduct this image from the original image. The resulting image is as expected; After performing the enhancement process,the high quality of the image can be indicated using the Tenengrad criterion. The resulting image manifested the difference in certain areas, the dimension and the depth as well. Histogram equalization technique can also be applied to change the images color.

scholarly journals Comparison and Investigation of Exosomes Derived from Platelet-Rich Plasma Activated by Different Agonists

2021 ◽  
Vol 30 ◽  
pp. 096368972110178
Author(s):  
Shunli Rui ◽  
Yi Yuan ◽  
Chenzhen Du ◽  
Peiyang Song ◽  
Yan Chen ◽  
...  
Keyword(s):  
Calcium Gluconate ◽  
Platelet Rich Plasma ◽  
Saline Group ◽  
Signal Pathway ◽  
Biological Functions ◽  
High Quality ◽  
Bioactive Substances ◽  
The Difference ◽  
Erk Signal Pathway

PRP-Exos are nanoscale cup-shaped vesicles that carry a variety of proteins, mRNAs, microRNAs, and other bioactive substances. PRP-Exos can be formed through several induction pathways, which determine their molecular profiles and facilitate their tailormade participation in intercellular communication. Currently, little is known on how the PRP-Exos activation method influences the quality and quantity of PRP-Exos. The present study aims to observe and analyze the number, profile, and growth factors of PRP-Exos through TEM, Nanoflow, and WB after PRP activation and compare the difference in function of PRP-Exos on HUVECs, with different stimuli (calcium gluconate, thrombin, or both). We found that PRP activated with both thrombin and calcium gluconate harvested the highest concentration of exosomes [(7.16 ± 0.46) × 1010 particles/ml], compared to thrombin group [(4.87 ± 0.15) × 1010 particles/ml], calcium gluconate group [(5.85 ± 0.43) × 1010 particles/ml], or saline group [(7.52 ± 0.19) × 109 particles/ml], respectively ( P < 0.05) via Nanoflow analysis. The WB analysis showed that cytokines (VEGF, PDGFBB, bFGF, TGF-β) are differentially encapsulated in PRP-Exos, depending on the PRP stimulus, in which the mixture-PRP-Exos yielded the highest concentration of cytokines. In the function assay of PRP-Exos on HUVECs, the mixture-PRP-Exos promoted HUVECs proliferation, increased HUVECs migration, promoted the formation of vessel-like by HUVECs via the AKT ERK signal pathway more dramatically, compared with other groups. In summary, our studies showed that PRP activated by the mixture of calcium gluconate and thrombin harvested the best quality of exosomes which had the top biological functions. This study provides a protocol for selecting appropriate PRP activators to obtain high-quality exosomes for future applications.

scholarly journals Comparison of PM2.5 in Seoul, Korea Estimated from the Various Ground-Based and Satellite AOD

2021 ◽  
Vol 11 (22) ◽  
pp. 10755
Author(s):  
Sang-Min Kim ◽  
Ja-Ho Koo ◽  
Hana Lee ◽  
Jungbin Mok ◽  
Myungje Choi ◽  
...  
Keyword(s):  
Satellite Remote Sensing ◽  
Correlation Coefficients ◽  
Reasonable Accuracy ◽  
High Quality ◽  
Polar Orbit ◽  
Winter Condition ◽  
The Difference ◽  
Mlr Model

Based on multiple linear regression (MLR) models, we estimated the PM2.5 at Seoul using a number of aerosol optical depth (AOD) values obtained from ground-based and satellite remote sensing observations. To construct the MLR model, we consider various parameters related to the ambient meteorology and air quality. In general, all AOD values resulted in the high quality of PM2.5 estimation through the MLR method: mostly correlation coefficients >~0.8. Among various polar-orbit satellite AODs, AOD values from the MODIS measurement contribute to better PM2.5 estimation. We also found that the quality of estimated PM2.5 shows some seasonal variation; the estimated PM2.5 values consistently have the highest correlation with in situ PM2.5 in autumn, but are not well established in winter, probably due to the difficulty of AOD retrieval in the winter condition. MLR modeling using spectral AOD values from the ground-based measurements revealed that the accuracy of PM2.5 estimation does not depend on the selected wavelength. Although all AOD values used in this study resulted in a reasonable accuracy range of PM2.5 estimation, our analyses of the difference in estimated PM2.5 reveal the importance of utilizing the proper AOD for the best quality of PM2.5 estimation.

The Public Procurement and the Quality of Services: The Case of Moscow Hospitals

2020 ◽  
pp. 118-131
Author(s):  
Margarita  V. Kravtsova
Keyword(s):  
Public Procurement ◽  
Medical Services ◽  
Key Factors ◽  
High Quality ◽  
Factors Affecting ◽  
The Public ◽  
Goods And Services ◽  
The Difference ◽  
Positive Effect

The work is devoted to the search for answers to the question: “Are there any differences in the public procurement of customers who provide services of different quality?”. The article identifies the stages of the hospital procurement process in the contract system and highlights the main customer strategies used in the auction. The results of an independent quality assessment are examined and comparative hospital characteristics with low and high quality rating are conducted. The hospital needs according to the types of purchases and their annual volumes of contracts are analyzed. The advantages of competitive procedures are determined and the key factors affecting the level of competition with possible risks of unreliable execution of contracts are identified. The empirical study is based on the database which includes 5390 contracts of 2 hospitals in Moscow for years of 2011–2017. Using the methods of econometric analysis, in particular, the method of least squares and the difference in the average, the hypothesis is tested the high competition has a positive effect on the quality of medical services. The constructed regression models show that the customer providing high quality services has low competition and small rebates at the auction. At the same time there are more contract terms, delays in the supply of goods and services as compared with the customer providing low quality services. Thus it was found that the underestimation of competition at the auction indicates the desire of the hospital to guarantee a higher quality of medical services to patients while as aggressive bids of participants lead to the supply of poor purchases. The results of the study may be useful for the competent authorities in the development of legal acts for the participants of the contract system in the field of health procurement.

Analysis of Quality of Services in Higher Education Institutions

2020 ◽  
pp. 349-365
Author(s):  
Ivana Jošanov-Vrgović ◽  
Ana Jovičić Vuković ◽  
Nataša Papić-Blagojević ◽  
Dragana Bolesnikov
Keyword(s):  
Higher Education ◽  
Higher Education Institutions ◽  
Perceived Quality ◽  
Competitive Environment ◽  
Quality Of Services ◽  
High Quality ◽  
Main Factors ◽  
The Difference ◽  
To Receive

An overview of domestic and foreign literature shows that the concept of quality of services at higher education institutions (HEIs) is the focus. Quality of service is one of the main factors of competitive advantage. Perceived quality of services in HEIs can be defined as the difference between what students expect to receive and their perceptions of what they really get. If HEIs get acquainted with students' expectations, they will have the opportunity to adjust their behavior to what is expected of them, and thus to positively influence on the students' perceived quality of services. Globalization has created a more competitive environment and opened market for HEIs. It affected on ensuring high quality in HEIs. The quality of HEIs is of key importance for a society because the students, employers, and society have the benefits of it, and quality education contributes to economic development of the country.

Biomedical Sensors

2013 ◽  
pp. 356-436
Author(s):  
Sverre Grimnes ◽  
Jan Olav Høgetveit
Keyword(s):  
Electrical Properties ◽  
Medical Equipment ◽  
Electrical Signal ◽  
The Other ◽  
Electrical Safety ◽  
High Quality ◽  
Biomedical Sensors ◽  
Physiological Variables ◽  
Technical Requirements

This chapter addresses biomedical sensors, which are important factors for the quality of measurement of biological and physiological variables, and thus deserve close attention both with respect to the medical functions and the technical requirements. There are special demands for biomedical sensors, particularly for invasive sensors that must pass sterilization by temperature or radiation at much higher levels than the rest of the medical equipment. On the other hand, miniaturization, mechanical strength, electrical safety, and sterility are important elements of the sensor design process. The sensor determines the accessibility, spatial resolution, accuracy, sensitivity, selectivity, and response time of the measurement. In order to convert the parameter of interest into an electrical signal suited for medical use, a transducing element is necessary. Knowledge of the complete chain of transducer materials, their electrical properties, and integration with bio-amplifiers are therefore necessary to design high-quality biomedical sensors.

High Conductive a-Si:H/a-SiC:H:F Super Lattice Prepared by a Chemically Controlled Method

1987 ◽  
Vol 95 ◽  
Author(s):  
H. Koinuma ◽  
M. Kawasaki ◽  
K. Fueki
Keyword(s):  
Electrical Properties ◽  
Barrier Layer ◽  
Layered Structure ◽  
Gas Mixture ◽  
Optical And Electrical Properties ◽  
Pulsed Plasma ◽  
Silicon Source ◽  
Cvd Method ◽  
The Difference

AbstractAmorphous super lattices composed of a-Si:H and a-SiC:H:F layers were continuously prepared from a gas miture of CF4 and either SiH4 or Si2 H6 by the pulsed plasma and photo (PP&P) CVD method. The method utilizes the difference in photochemical reactivity of the source gases for the formation of layered structure. The layered films prepared by using Si2H6 as silicon source under the condition that they had optical gaps up to 2.0 eV were found to show photoconductivities higher not only than those of a-SiC:H:F films prepared from the same gas mixture by the continuous plasma and photo hybrid CVD but also than those of a-Si:H films by the photo CVD. From the comparison of optical and electrical properties of super lattices prepared, the photoconductivity of the films is suggested to be primarily dependent on the quality of barrier layer rather than on the quality of well layer.

Standards Certifications and Exports Performance

2016 ◽  
pp. 382-401
Author(s):  
Cristina Robledo-Ardila ◽  
Sara Aguilar-Barrientos ◽  
Kelly Gonzalez-Tapias ◽  
Ana María Gomez-Trujillo ◽  
Camila Uribe-Villa
Keyword(s):  
Food Industry ◽  
Export Performance ◽  
Processed Food ◽  
Structured Interviews ◽  
High Quality ◽  
The World ◽  
Potential Benefits ◽  
The Difference ◽  
The Impact

The integration of the world economy and the internationalization of companies have resulted in consumers' demand for high quality goods. Standards have emerged as a way of reducing the information asymmetries that consumers face when purchasing a product, and have gained importance in the processed food industry as they allow them to assess the quality of goods and may influence the export performance of certified firms (An & Maskus, 2009). Certifications may act as promoters of international trade, but they can also constitute a barrier when the costs associated with the certification process exceed the potential benefits (Jarasueiya et al., 2006). The present study aims to compare the export performance of certified vs. non-certified firms in the Colombian processed food industry. A Mann-Whitney Test was used to analyze the difference of exports value for the selected companies, and then, non-structured interviews to the quality managers of these companies were conducted to gain greater understanding about the impact of standards certifications on their export performance.

scholarly journals Geometrical and Friction Properties of Perennial Grasses and Their Weeds in View of an Electro-Separation Method

2015 ◽  
Vol 29 (2) ◽  
pp. 185-191
Author(s):  
Stepan J. Kovalyshyn ◽  
Viktor O. Dadak ◽  
Vitalij V. Sokolyk ◽  
Stanisław Grundas ◽  
Mateusz Stasiak ◽  
...  
Keyword(s):  
Electric Field ◽  
Red Clover ◽  
Perennial Grasses ◽  
Geometrical Parameters ◽  
Friction Coefficients ◽  
Surface Conditions ◽  
Main Crop ◽  
Separating Plane ◽  
Electrical Components ◽  
Seed Mixtures

Abstract Many seed mixtures of herbs are difficult to separate. This is confirmed by studies determining the basic geometrical and friction properties of the seeds of perennial grasses and seeds of their weeds. The results show that in most cases the value of their geometrical parameters (length, thickness, and width) and friction properties (friction coefficients for different external surfaces of internal friction coefficients) are substantially similar and differ slightly among each other. This is the evidence that these properties are impractical to use in the process of separation as signs of divisibility. In the paper, a method for electro-separation of seed mixtures of herbs based on the use of complex physical, mechanical properties and electrical components in the separation are presented. The electric field that acts as an additional working body allows considering the surface conditions and biological status of seed mixtures of particles and significantly expands the functionality of the separators. Confirmation of the effectiveness of the proposed method for separation can be seen in the example of purification of red clover and sorrel seeds. By imposition of an electric field on an inclined moving separating plane, we can completely separate weed seeds from the main crop. The results confirm the effectiveness of the electro-separating method.

scholarly journals Moxibustion for Primary Dysmenorrhea at Different Interventional Times: A Systematic Review and Meta-Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Chao-qin Gou ◽  
Jing Gao ◽  
Chen-xi Wu ◽  
Ding-xi Bai ◽  
Hong-yuan Mou ◽  
...  
Keyword(s):  
Systematic Review ◽  
Methodological Quality ◽  
Meta Analysis ◽  
Effective Rate ◽  
Controlled Trials ◽  
Primary Dysmenorrhea ◽  
High Quality ◽  
Randomized Controlled ◽  
The Difference

Primary dysmenorrhea (PD) is one of the most common diseases in gynecology at present. Some clinical trials have reported the effects of moxibustion and confirmed temporal factors are the important elements influencing the efficacy of moxibustion. However, no systematic review has yet been conducted. In this study, we assessed the effects of moxibustion in patients with PD enrolled in randomized controlled trials (RCTs) and the difference among different intervention times to start moxibustion. We extracted data for studies searched from 10 electronic databases and evaluated the methodological quality of the included studies. We discussed three outcomes: effective rate, pain remission, and the level of PGF2αin serum. Current clinical researches showed that, compared with nonmoxibustion treatments for PD, moxibustion leads to higher effective rate and lower level of PGF2αin serum. However, there was no difference in using moxibustion to treat PD at different intervention times. Based on the theory of Chinese medicine and the results of this study, choosing 5 ± 2 days before menstruation to start moxibustion can achieve good efficacy for PD patients. However, more high-quality RCTs are needed to confirm the conclusions.

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