Study on the Global Regularity for Two-Dimensional Magnetohydrodynamic and Boussinesq Equations

Whether the classical solutions of two-dimensional incompressible ideal MHD equations or inviscid Boussinesq equations can develop a finite time singularity or globally regular for all time from smooth initial data with finite energy is an outstanding open problem in fluid dynamics. We study these equations to explore how far one can go beyond these two cases and still can prove the global regularity. \\First, the global regularity for the 2D MHD equations with horizontal dissipation and horizontal diffusion is studied. We prove that the horizontal components of any solution admit a global bound in any Lebesgue space L^{2r}, 1\leq r <\infty and the bound grows no faster than the order of \sqrt{r\log r} as r increases. Furthermore, we prove that any possible blow-up can be controlled by the L^\infty-norm of the horizontal components. We establish the global regularity of slightly regularized 2D MHD equations with horizontal dissipation and horizontal magnetic diffusion. The global regularity issue of the MHD equation with horizontal dissipation and horizontal magnetic diffusion is extremely hard. The classical energy method does not work. By using the techniques from the Littlewood- Paley decomposition and logarithmic bound for the horizontal components, we are able to resolve the global regularity issue of the 2D MHD equations with horizontal dissipation and horizontal magnetic diffusion. \\Second, the global well-posedness for the 2D Euler-Bousinesq equations with a singular velocity is investigated. We prove the global existence and uniqueness of the solutions to the initial value problem of 2D Euler-Boussinesq equations when the velocity field is double logarithmically more singular than the standard velocity field given by the Biot-Savart law. \\Third, the global existence, and uniqueness for the 2D Navier-Stokes-Boussinesq equation with more general dissipation is studied. We prove that the solution is globally regular even the critical dissipation is logarithmically weaker.Mathematic

Modified atmosphere packaging of capsicum for extending shelf life under coolbot condition

Capsicum is one of the high value vegetable crops in Nepal. Its demand in kitchen is increasing due to urbanization and increased awareness on its health benefit. Its commercial cultivation has been started in protected as well as open field conditions. It fetches higher price in market but has very short storage life under ordinary storage condition. An experiment was carried out to evaluate the modified atmosphere packaging (MAP) on extension of shelf-life of capsicum fruit. Fruit were harvested at full mature stage with smooth and shiny appearance from farmer's field grown under protected condition at Chitwan, Nepal. The fruits were brought to postharvest laboratory of National Horticulture Research Centre, pre-cooled for 3-4 hours, cleaned with muslin cloth and packed in 25 micron Low Density Polyethylene (LDPE) packaging with different number of pinhole sized perforations viz. without pinholes, eight pinholes, sixteen pinholes, twenty four pinholes and control (without MAP). The study was conducted in completely randomized block design with five treatments and four replications. Fruits were kept at coolbot storage (9.8+2 ºC, 86+5% RH) till 30 days and analyzed for various postharvest physical, chemical and physiological parameters at every 10, 20 and 30 days of storage. The result showed that LDPE packaging influenced on reduction of physiological loss in weight (PLW), spoilage loss, ascorbic acid content, TA, freshness, firmness and shelf life. The modified atmosphere packaging (MAP) without pinholes showed the minimum PWL (1.71%) and the optimum fruit freshness (4.76) but the spoilage loss was the maximum (14%). Among the packaging, MAP with 8 pinholes maintained majority of postharvest quality retention with reduced physiological loss in weight (4.15 %), freshness (4.5) and spoilage loss (2%)

AMMI and GGE biplot analysis of yield of different elite wheat line under terminal heat stress and irrigated environments

Wheat crop contributes to a major portion of the agriculture economy of Nepal. It is ranked as the third major cereal crop of the country even though, it faces terminal heat stress which speeds up the grain filling rate and shortens the filling period, causing reduction in grain weight, size, number and quality losses. We can minimize this loss through a genotypic selection of high-yielding lines by understanding the genotype-environment interaction. The objective of this research is to obtain a high yielding line with a stable performance across the environments. In order to do so, we conducted an experiment using eighteen elite wheat lines and two check varieties in alpha-lattice design with two replications in different environments viz. irrigated and terminal heat stress environment from November 2019 to April 2020. The analysis of variance revealed that genotype, environment and their interaction had a highly significant effect on the yield. Furthermore, the which-won–where model indicated specific adaptation of elite lines NL 1179, NL 1420, BL 4407, NL 1368 to the irrigated environment and Bhirkuti to the terminal heat-stressed environment. Similarly, the mean-versus-stability study indicated that elite lines BL 4407, NL 1368, BL 4919, NL 1350, and NL 1420 had above-average yield and higher stability whereas elite lines Gautam, NL 1412, NL 1376, NL 1387, NL 1404, and NL 1381 had below-average yield and lower stability. The ranking of elite lines biplot, PC1 explaining 73.6% and PC2 explaining 26.4% of the interaction effect, showed the rank of elite line, NL 1420 > NL 1368> NL 1350 > other lines, close to the ideal line. On the basis of the obtained results, we recommend NL 1420 with both the high yield and stability is suited across both the environments, while NL 1179 and Bhirkuti is adapted specifically for irrigated and terminal heat stress environment, respectively

Generalized 2D Euler-Boussinesq equations with a singular velocity

Abstract This paper studies the global (in time) regularity problem concerning a system of equations generalizing the two-dimensional incompressible Boussinesq equations. The velocity here is determined by the vorticity through a more singular relation than the standard Biot-Savart law and involves a Fourier multiplier operator. The temperature equation has a dissipative term given by the fractional Laplacian operator √ − . We establish the global existence and uniqueness of solutions to the initial-value problem of this generalized Boussinesq equations when the velocity is &quot;double logarithmically&quot; more singular than the one given by the Biot-Savart law. This global regularity result goes beyond the critical case. In addition, we recover a result of Chae, Constantin and Wu [8] when the initial temperature is set to zero

Prevalence of Gall Stones in Liver Cirrhosis

Introduction: Increased incidence and prevalence of gallstones in liver cirrhosis has already been reported by many studies. This study aimed to investigate the prevalence of gallstone disease in Nepali patients with liver cirrhosis and to identify risk factors for gallstone formation. &#13; Methods: Consecutive patients of liver cirrhosis presenting to liver clinic from January, 2010 to December, 2012 were evaluated for GS by ultrasonography at their first visit. Liver cirrhosis was diagnosed on the basis of clinical features, laboratory parameters, ultrasonography, and/or histopathology. &#13; Results: Two hundred and twenty four LC patients were studied. Male to female ratio was 2.3:1. Alcohol was the major etiological factor for LC followed by hepatitis B, alone or in conjunction with alcohol. Seventy-four patients (33%) were found to have GS. Incidence of GS was more in advance stage of cirrhosis. There was no significant correlation between formation of GS and etiology of LC, except for the HCV related liver cirrhosis, in which it was present in 39% of the patients. More the advance disease,more was the incidence as 57% of Child-C patients had GS. Portal vein diameter was also associated with GS formation. When portal vein diameter was more than 13 mm, there was more GS formation. &#13; Conclusions: One third of the patients of LC showed GS at the presentation. Patients with HCV related cirrhosis are more prone to develop GS than other. Severity of the disease and portal vein diameter was found to be associated with GS formation. &#13; Keywords: gallstones; liver cirrhosis; ultrasonography

Prevalence of Hepatitis D Among Patients with Hepatitis B Viral Infection Attending a Tertiary Care Centre of Nepal

Introduction: Worldwide there is variation in prevalence of Hepatitis D viral infection. Superinfection and co infection with hepatitis B viral infection is known to occur in 15-20 million people. Methods: This was a descriptive cross-sectional hospital based study carried out in NAMS, Bir hospital, Kathmandu, Nepal from period of January 2017 to June 2017. Consecutive patients of chronic hepatitis B viral infection of HBsAg positive with more than two-time upper normal limit of ALT were enrolled and tested for HDV IgG. Results: Forty patients were enrolled during study period. Mean age was 30.9±12.2 years. Males were 28 (70%) and females 12 (30%). Most of the patients were asymptomatic for HBV infection 32 (80%). HBeAg negative chronic hepatitis was most commonly present in 31 (77.5%). Family history of Hepatitis B viral infection was seen in 7 (17.5%) and sexual promiscuity in 5 (12.5%) as the mode of acquisition of hepatitis B viral infection. HBcIgM was positive in three patients with mean HBV DNA of 4.97x105±4.5x105 IU/ml in HBeAg positive group. HDV IgG was negative in all patients. Conclusions: Coinfection and superinfection of hepatitis D virus were found to be uncommon at Bir hospital, Nepal. Keywords: HbsAg; HDV DNA; HDV IgG; Hepatitis B; Hepatitis D

Prevalence of Gall Stones in Liver Cirrhosis

Introduction: Increased incidence and prevalence of gallstones in liver cirrhosis has already been reported by many studies. This study aimed to investigate the prevalence of gallstone disease in Nepali patients with liver cirrhosis and to identify risk factors for gallstone formation.  Method: Consecutive patients of liver cirrhosis presenting to liver clinic from January, 2010 to December, 2012 were evaluated for GS by ultrasonography at their  rst visit. Liver cirrhosis was diagnosed on the basis of clinical features, laboratory parameters, ultrasonography, and/or histopathology. Result: Two hundred and twenty four LC patients were studied. Male to female ratio was 2.3:1. Alcohol was the major etiological factor for LC followed by hepatitis B, alone or in conjunction with alcohol. Seventy-four patients (33%) were found to have GS. Incidence of GS was more in advance stage of cirrhosis. There was no signi cant correlation between formation of GS and etiology of LC, except for the HCV related liver cirrhosis, in which it was present in 39% of the patients. More the advance disease,more was the incidence as 57% of Child-C patients had GS. Portal vein diameter was also associated with GS formation. When portal vein diameter was more than 13 mm, there was more GS formation. Conclusions: One third of the patients of LC showed GS at the presentation. Patients with HCV related cirrhosis are more prone to develop GS than other. Severity of the disease and portal vein diameter was found to be associated with GS formation.  Keywords: gallstones; liver cirrhosis; ultrasonography

First camera trap record of Striped Hyena Hyaena hyaena (Linnaeus, 1758) (Mammalia: Carnivora: Hyaenidae) in Parsa National Park, Nepal

© Regmi et al. 2022. Creatve Commons Atributon 4.0 Internatonal License. JoTT allows unrestricted use, reproducton, and distributon of this artcle in any medium by providing adequate credit to the author(s) and the source of publicaton.The Striped Hyena occurs in the Tarai and midhill regions of Nepal, where limited information is available on species distribution. A camera trap survey was conducted in Parsa National Park in 2016 (Feb–May) and 2016–2017 (Nov–Feb) to monitor tigers at 158 locations for 21 days (6,615 trap efforts in total). This study successfully captured the 15 hyena images in 5 grids of eastern part (named as extension area) of national park. A total of 17 mammal species were captured simultaneously in hyena captured grid during the survey period. The presence of hyenas in Parsa National Park indicates the collective efforts of the government, conservation organizations and local communities in hyena conservation. A detailed ecological study of this species has been recommended for designing hyena conservation plan in the regionpublishedVersio