Growth improvement of F1 generation of Clarias gariepinus through selective breeding

Selective breeding studies were carried out in four genetic mating combinations of Clarias gariepinus with the aim of improving its growth performance. F2 intraspecific and backcross were produced using the best male and female of the best genetic mating combination in the F generation in crosses of three wild strains of Clara gariepinus. The highest percentage hatchability (75%) was recorded in female Kainji parental and male Kainji F1. and the least (53.67%) in female and Male Kainji Fl. The cross involving female Kainji F1. and Male Kainji Parental had the best survival (49%) indoor and also best (38.67%) outdoor, while the least (37.67%) was recorded in female Kainji parental and Male Kainji F1 and also gave the least (32.67%) outdoor. The female Kainji F1, and male Kainji parental gave the best growth performance (1.61 g) at 19 days indoor rearing, while female and male Kainji parental gave the least (1.50g). At the end of seven months rearing outdoor, the female Kainji parental and male Kainji F1. gave the best growth performance of(222.49g) and the least (180.66) was recorded in female Kainji F1 and male Kainji parental

Experimental research and development on the natural convection of suspensions of nanoparticles

Suspensions of nanoparticles, widely known as nanofluids, are considered as advanced heat transfer media for thermal management and conversion systems. Research on their convective thermal transport is of paramount importance for their applications in such systems such as heat exchangers and solar collectors. This paper presents experimental research on the natural convection heat transfer performances of nanofluids in di erent geometries from thermal management and conversion perspectives. Experimental results and available experiment-derived correlations for the natural thermal convection of nanofluids are critically analyzed. Other features such as nanofluid preparation, stability evaluation and thermophysical properties of nanofluids that are important for this thermal transfer feature are also briefly reviewed and discussed. Additionally, techniques (active and passive) employed for enhancing the thermo-convection of nanofluids in di erent geometries are highlighted and discussed. Hybrid nanofluids are featured in this work as the newest class of nanofluids, with particular focuses on the thermophysical properties and natural convection heat transfer performance in enclosures. It is demonstrated that there has been a lack of accurate stability evaluation given the inconsistencies of available results on these properties and features of nanofluids. Although nanofluids exhibit enhanced thermophysical properties such as viscosity and thermal conductivity, convective heat transfer coe cients were observed to deteriorate in some cases when nanofluids were used, especially for nanoparticle concentrations of more than 0.1 vol.%. However, there are inconsistencies in the literature results, and the underlying mechanisms are also not yet well-understood despite their great importance for practical applications.The Fundação para a Ciência e Tecnologia (FCT), Portugalhttp://www.mdpi.com/journal/nanomaterialsam2021Mechanical and Aeronautical Engineerin

Thoria-based cermet nuclear fuel : sintered microsphere fabrication by spray drying.

Cermet nuclear fuels have been demonstrated to have significant potential to enhance fuel performance because of low internal fuel temperatures and low stored energy. The combination of these benefits with the inherent proliferation resistance, high burnup capability, and favorable neutronic properties of the thorium fuel cycle produces intriguing options for advanced nuclear fuel cycles. This paper describes aspects of a Nuclear Energy Research Initiative (NERI) project with two primary goals: (1) Evaluate the feasibility of implementing the thorium fuel cycle in existing or advanced reactors using a zirconium-matrix cermet fuel, and (2) Develop enabling technologies required for the economic application of this new fuel form. Spray drying is a physical process of granulating fine powders that is used widely in the chemical, pharmaceutical, ceramic, and food industries. It is generally used to produce flowable fine powders. Occasionally it is used to fabricate sintered bodies like cemented carbides, but it has not, heretofore, been used to produce sintered microspheres. As a physical process, it can be adapted to many powder types and mixtures and thus, has appeal for nuclear fuels and waste forms of various compositions. It also permits easy recycling of process ''wastes'' and minimal chemical waste streams that can arise in chemical sol/gel processing. On the other hand, for radioactive powders, it presents safety challenges for processing these materials in powder form and in achieving microspheres of high density and perfection

Experimental investigation on stability, viscosity, and electrical conductivity of water-based hybrid nanofluid of MWCNT-Fe2O3

The superiority of nanofluid over conventional working fluid has been well researched and proven. Newest on the horizon is the hybrid nanofluid currently being examined due to its improved thermal properties. This paper examined the viscosity and electrical conductivity of deionized water (DIW)-based multiwalled carbon nanotube (MWCNT)-Fe2O3 (20:80) nanofluids at temperatures and volume concentrations ranging from 15 ◦C to 55 ◦C and 0.1–1.5%, respectively. The morphology of the suspended hybrid nanofluids was characterized using a transmission electron microscope, and the stability was monitored using visual inspection, UV–visible, and viscosity-checking techniques. With the aid of a viscometer and electrical conductivity meter, the viscosity and electrical conductivity of the hybrid nanofluids were determined, respectively. The MWCNT-Fe2O3/DIW nanofluids were found to be stable and well suspended. Both the electrical conductivity and viscosity of the hybrid nanofluids were augmented with respect to increasing volume concentration. In contrast, the temperature rise was noticed to diminish the viscosity of the nanofluids, but it enhanced electrical conductivity. Maximum increments of 35.7% and 1676.4% were obtained for the viscosity and electrical conductivity of the hybrid nanofluids, respectively, when compared with the base fluid. The obtained results were observed to agree with previous studies in the literature. After fitting the obtained experimental data, high accuracy was achieved with the formulated correlations for estimating the electrical conductivity and viscosity. The examined hybrid nanofluid was noticed to possess a lesser viscosity in comparison with the mono-particle nanofluid of Fe2O3/water, which was good for engineering applications as the pumping power would be reduced.The Fundação para a Ciência e Tecnologia (FCT), Portugalhttp://www.mdpi.com/journal/nanomaterialspm2022Mechanical and Aeronautical Engineerin

Frictional drag between non-equilibrium charged gases

The frictional drag force between separated but coupled two-dimensional electron gases of different temperatures is studied using the non-equilibrium Green function method based on the separation of center-of-mass and relative dynamics of electrons. As the mechanisms of producing the frictional force we include the direct Coulomb interaction, the interaction mediated via virtual and real TA and LA phonons, optic phonons, plasmons, and TA and LA phonon-electron collective modes. We found that, when the distance between the two electron gases is large, and at intermediate temperature where plasmons and collective modes play the most important role in the frictional drag, the possibility of having a temperature difference between two subsystems modifies greatly the transresistivity.Comment: 8figure

The influence of obtaining and heat treatment conditions on the structure of As₂S₃-SbSI system

(As₂S₃)₁₀₀₋x(SbSI)x (x = 80 and 90) glasses were prepared by cooling homogenized melts from 720…750 K in cold water. Their structure and structural changes under heat treatment of glasses are confirmed by studies of micro-Raman scattering and X-ray diffraction. In the matrix of these glasses, we observed SbSI nanocrystalline inclusions. It has been shown that the sizes of crystalline inclusions are dependent on the heat treatment regimes

Political Radicalization as a Communication Process

Based on data taken from 412 adult education students in Montreal, Quebec, Canada, this research attempts to show that attitudes toward French Canadian Separatism by the sample members can be accounted for by differentiaf communication processes. Results show that attitudes held by sample members are well explained (R2 = .64) by a weighted average of the information they received from interpersonal and media sources. The resultant attitude shows substantial effects on behaviors related to separatism for the same respondents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67215/2/10.1177_009365027400100301.pd

Random walks and polymers in the presence of quenched disorder

After a general introduction to the field, we describe some recent results concerning disorder effects on both `random walk models', where the random walk is a dynamical process generated by local transition rules, and on `polymer models', where each random walk trajectory representing the configuration of a polymer chain is associated to a global Boltzmann weight. For random walk models, we explain, on the specific examples of the Sinai model and of the trap model, how disorder induces anomalous diffusion, aging behaviours and Golosov localization, and how these properties can be understood via a strong disorder renormalization approach. For polymer models, we discuss the critical properties of various delocalization transitions involving random polymers. We first summarize some recent progresses in the general theory of random critical points : thermodynamic observables are not self-averaging at criticality whenever disorder is relevant, and this lack of self-averaging is directly related to the probability distribution of pseudo-critical temperatures $T_c(i,L)$ over the ensemble of samples $(i)$ of size $L$. We describe the results of this analysis for the bidimensional wetting and for the Poland-Scheraga model of DNA denaturation.Comment: 17 pages, Conference Proceedings "Mathematics and Physics", I.H.E.S., France, November 200

Pre-M Phase-promoting Factor Associates with Annulate Lamellae in Xenopus Oocytes and Egg Extracts

We have used complementary biochemical and in vivo approaches to study the compartmentalization of M phase-promoting factor (MPF) in prophase Xenopus eggs and oocytes. We first examined the distribution of MPF (Cdc2/CyclinB2) and membranous organelles in high-speed extracts of Xenopus eggs made during mitotic prophase. These extracts were found to lack mitochondria, Golgi membranes, and most endoplasmic reticulum (ER) but to contain the bulk of the pre-MPF pool. This pre-MPF could be pelleted by further centrifugation along with components necessary to activate it. On activation, Cdc2/CyclinB2 moved into the soluble fraction. Electron microscopy and Western blot analysis showed that the pre-MPF pellet contained a specific ER subdomain comprising "annulate lamellae" (AL): stacked ER membranes highly enriched in nuclear pores. Colocalization of pre-MPF with AL was demonstrated by anti-CyclinB2 immunofluorescence in prophase oocytes, in which AL are positioned close to the vegetal surface. Green fluorescent protein-CyclinB2 expressed in oocytes also localized at AL. These data suggest that inactive MPF associates with nuclear envelope components just before activation. This association may explain why nuclei and centrosomes stimulate MPF activation and provide a mechanism for targeting of MPF to some of its key substrates

Professionalism, Golf Coaching and a Master of Science Degree: A commentary

As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues