71 research outputs found
Invariant measures of piecewise concave dynamical systems via maximum entropy optimization method
No full textPiecewise Concave Dynamical System (PCDS) has its wide application in various science fields.
Many real-world problems can be modeled into mathematical models via PCDS. First, we let T:
[0,1] → [0,1] be a piecewise concave transformation/maps (PCDS) and study the existence of
absolutely continuous invariant measures. Then, we present a maximum entropy optimization
method for approximating densities of Piecewise Concave Maps. A numerical example will be
presented to compare the approximate densities of Piecewise Concave Maps using the maximum
entropy method and the actual densities of the Piecewise Concave Maps
Effects of irrigation rates on cotton yield as affected by soil physical properties and topography in the southern high plains
No full text© 2021 Neupane et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Lack of precipitation and groundwater for irrigation limits crop production in semi-arid regions, such as the Southern High Plains (SHP). Advanced technologies, such as variable rate irrigation (VRI), can conserve water and improve water use efficiency for sustainable agriculture. However, the adoption of VRI is hindered by the lack of on-farm research focusing on the feasibility of VRI. The objective of this study was to assess the effect of irrigation rates on cotton yield as affected by soil physical properties and topography in the Southern High Plains. This study was conducted in two fields within a 194-ha commercially managed farm in Hale County, Texas, in 2017. An irrigation treatment with three rates was implemented in a randomized complete block design with two replications as separate blocks in each field. A total of 230 composite soil samples were collected from the farm in spring 2017 and analyzed for texture. Information on apparent soil electrical conductivity (ECa), elevation, and final yield were collected from the fields. A statistical model showed that the effect of irrigation rates on cotton yield depended on its interaction with soil physical properties and topography. For example, areas with slope >2% and sand content >50% had no significant response to higher irrigation rates. This model suggests that applying irrigation amounts based on the yield response can be a basis for VRI. This study provides valuable information for site-specific irrigation to optimize crop production in fields with significant variability in soil physical properties and topography
Study Of Mercaptobenzimidazoles As Inhibitors For Copper Corrosion: Down to the Molecular Scale
No full textThe initiation of corrosion can be triggered by defects in the adsorbed layer of organic inhibitors. A detailed knowledge of the intermolecular forces between the inhibitor molecules and the interfacial bonding will be decisive to unravel the mechanisms driving the corrosion initiation. In this work, adsorbed organic layers of 2-mercapto-5-methoxybenzimidazole (SH-BimH-5OMe) and 5-amino-2-mercaptobenzimidazole (SH-BimH-5NH2) were compared regarding their performance mitigating copper corrosion. Atomic force microscopy was used to address the stability and intermolecular forces of the self-assembled monolayers, using imaging and force measurement modes. For a film formed by amino-derivative molecules, a gold-coated tip frequently picked up individual molecules (molecular fishing) in force-distance measurements. For layers of the methoxy-derivative, no fishing events were observed, pointing to a constant functional layer. X-ray photoelectron spectroscopy revealed that SH-BimH-5OMe molecules form a stronger bond with the surface and more stable SAM layers on Cu surfaces as compared to SH-BimH-5NH2 molecules. Results of computational density functional theory modeling and electrochemical corrosion tests are in line with the microscopy and spectroscopy results. In particular, with aid of computational modeling the less ordered structure of the SH-BimH-5NH2 monolayer is attributed to dual bonding ability of SH-BimH-5NH2 that can adsorb with either S or NH2 groups.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Formation of nanosized monolayer MoS2 by oxygen-assisted thinning of multilayer MoS2
No full textWe report the controllable nanosized local thinning of multi-layer (2 L and 3 L)-thickness MoS2 films down to the monolayer (1 L) thickness using the simple method of annealing in a dry oxygen atmosphere. The annealing temperature was optimized in the range of 240 °C to 270 °C for 1.5 h, and 1 L thick nanosized pits were developed on the uniform film of the 2 L and 3 L MoS2 grown using the chemical vapor deposition method. We characterized the formation of the 1 L nanosized pits using nanoscale confocal photoluminescence (PL) and Raman spectroscopy. We observed that the PL intensity increased and the Raman frequency shifted, representative of the characteristics of 1 L MoS2 films. A subsequent hydrogen treatment process was useful for removing the oxygen-induced doping effect resulting from the annealing. © 2016 Author(s)6711sciescopu
Simplistic correlations between molecular electronic properties and inhibition efficiencies: Do they really exist?
No full textThe often used simplistic correlations between molecular electronic parameters and experimentally determined corrosion inhibition efficiencies are critically evaluated for a set of 24 heterocyclic organic compounds, tested as corrosion inhibitors for copper in 3 wt.% NaCl aqueous solution. Twelve different molecular electronic descriptors—such as ionization potential, electron affinity, HOMO–LUMO gap, dipole moment—are tested and it is shown that none of them displays any noticeable correlation with the inhibition efficiency. Our results, therefore, cast serious doubt on reported correlations between such parameters and inhibition efficiency, obtained for only a few inhibitors, which are abundant in the literature. We also discuss some pros and cons of inhibition efficiency as a metric for evaluating the performance of corrosion inhibitors, and introduce a new metric termed inhibition power that uses the universal logarithmic scale and dimensionless decibel (dB) units.Team Peyman TaheriTeam Arjan Mo
Essential elements of game development : a case study EvilHuman Game
No full textThe game industries have been growing rapidly since the last decade. The main objective of this thesis was to develop a game from scratch to have a deeper look at the game development process. This thesis attempts to answer the following questions; what are the essential elements for game design, how to generate revenue through games by using different monetization models, what are the tools and software available today to create a game, what is game testing methodology and how it is implemented, and, finally, how to manage customer service. To know about whole game design process, one simple mobile game called“EvilHuman” was designed.
A fully functional game was completed using the Unity3D game engine and was published in Google Play Store to receive comments and feedbacks from the users. The game was downloaded between 100 – 500 times. The users who downloaded the game wrote reviews in Google Play Store, and the average rating was 4.6 out of 5. There were many challenges duringthe practical part of this thesis. The main challenge for this game was learning Unity3D, C# programming, game designing and modeling. However, some assets were used from the premade assets from the Unity3D asset store, which had made the design process easier.
The publishing of this game in Google Play has motivated the author to continue in the game development field because of suggestions and positive feedback, which were provided by the real users who downloaded the game and played it
Total Phenolic and Flavonoid Contents, and Preliminary Antioxidant, Xanthine Oxidase Inhibitory and Antibacterial Activities of Fruits of Lapsi (Choerospondias axillaris Roxb.), an Underutilized Wild Fruit of Nepal
No full textChoerospondias axillaris Roxb. (Anacardiaceae) is a deciduous tree, native to Nepal and the Himalayan region, that can reach a maximum height of 20 m. The study aimed to assess the total phenol, flavonoid, and carbohydrate content, and preliminary antioxidant potency, xanthine oxidase inhibition, and antibacterial properties of C. axillaris fruits extracts. Ethyl acetate, acetone, methanol, and water were used as extraction solvents. The quantitative analysis showed that the extracts had total polyphenols (68.28 μg to 154.91 μg gallic acid equivalent/mg extract), flavonoids (41.72 to 283.84 μg quercetin equivalent/mg extract), and carbohydrates contents (67.26 µg to 269.96 µg glucose equivalent/mg extract). The acetone extract exhibited the highest antioxidant activity (IC50: 15.72 µg/mL) and potent inhibition of xanthine oxidase (IC50: 20.80 µg/mL) among the extracts. The acetone extract exhibited the strongest antibacterial efficacy against Staphylococcus aureus and Bacillus cereus with inhibition zones of 13.76 mm and 12.56 mm, respectively. It also had the lowest minimum bactericidal concentration (MBC: 0.78 mg/mL) and minimum inhibitory concentration (MIC: 0.52 mg/mL) against S. aureus. In conclusion, the C. axillaris fruit extracts showed potent antioxidant, xanthine oxidase inhibitory, and antibacterial activities, suggesting their potential for pharmaceutical and nutraceutical applications. Further research should focus on the identification of active compounds and in vivo analysis of pharmacological activities
Effect of essential oil on shelf-life and quality attributes of tomato in Rupandehi, Nepal
No full textTomato (Lycopersicon esculentum Mill) is one of the most consumed vegetables in the world. Chemicals like Bavistin and Calcium Chloride used to enhance the postharvest life of tomatoes have detrimental effects on human health. An experiment was conducted on tomatoes to determine the effects of essential oils on their physical (color, firmness, weight loss) and chemical attributes (TSS, TA, Vitamin C, pH). Tomatoes were treated with different concentrations of lemon grass oil, calcium chloride (1%), and extract of Justicia adhatoda (100%), and the effects were analyzed along with the control. No significant difference in weight loss was observed among treatments recording maximum weight in Justicia extract treatment (12.86%) and minimum in the control (9.73%). Maximum firmness (5.71 Nmm-1) was recorded in 100% Asuro extract treatment on Day 14 while there was no significant difference in pH on treated tomatoes except on the 10th DAT. A significant difference was noted in TSS, titratable acidity on 4 DAT, and vitamin C content among treatments. TSS content increased up to 10 DAT and showed a gradual diminishing pattern in TSS content in almost all treatments on 12 DAT and 14 DAT where maximum TSS (4.933 Brix) was found in 1% CaCl2 and minimum TSS (3.466 Brix) was found in 200 ppm EO. Furthermore, minimum TA (0.21%) was observed in 200 ppm EO whereas maximum TA was found in tomatoes treated with 100% Asuro extract (0.36) at 14 days after treatment. Additionally, the highest content of Vitamin C (0.276 mgml-1) was recorded in tomatoes treated with 200 ppm of essential oil. There was a significant difference (p < 0.05) in the TSS/TA ratio among treatments during the experiment where the highest ratio (21.08) was observed in 1% CaCl2 and the lowest ratio (9.92) was obtained in 100% Asuro Extract at 14 days after treatment. The current study implies essential oils are potential alternatives to hazardous chemicals enhancing shelf life and safety for human health. It is advisable to carry out multiple experiments in a broader area using different varieties with various concentrations
A case of Echinococcus granulosus hepatic hydatid cyst together with pyogenic liver abscess in a Nepali patient
No full textHydatidic disease (echinococcosis) is a significant health problem in Nepal. In humans, mainly involves liver and commonly remains silent without symptoms or causing only mild pressure symptomatology. However, inadequate invasive medical procedures may cause the rupture of the cyst with serious complications, anaphylactic shock and death. Herein, we report the case of a Nepali patient who had been treated of a hepatic abscess with percutaneous drainage and antibiotics in a previous hospitalization. Study by drain fluid, ultrasonography and the magnetic resonance imaging revealed the presence of an intact Hydatidic cyst in the liver concomitantly with a percutaneously draining abscess (with free hooklets and a drain tube). This emphasizes the importance of putting the Hydatidic cyst into the differential diagnosis of liver abscess, especially in non-endemic areas
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