Determination of genetic Coefficients From Field Experiments For Ceres-Maize and Soygro Crop Growth Models

Lack of genetic coefficients is a reason crop models are not widely used. A project was therefore developed to evaluate a field method to calculate genetic coefficients for crop models. The phenology models fi-om SOYGRO v. 5.42 and CERES-Maize v. 2.1, with the existing genetic coefficients, were tested using data for soybean and maize grown under extreme photoperiods. Identical experiments were performed at two sites on Maui Island, Hawaii, over three years. The treatment design was a factorial of photoperiods (natural, natural + 0.5 h, 14-, 17-, and 20-h) and cultivars ('Bragg', 'Evans', 'Jupiter', and 'Williams' for soybean and Pioneer hybrids X304C, 3165, 3324, 3475, and 3790 for maize). Observations included development stage dates, yield, yield components, aboveground biomass weight, soil chemical analysis, and weather. Comparisons between observed and simulated results showed that soybean and maize development was well simulated. However, soybean yield and maize growth and yield were not well simulated. Further analysis suggested that model bias and parameter uncertainty accounted for nearly equal proportions of variation in soybean grain yield, whereas most maize growth and yield variation was due to model bias. SOYGRO and CERES-Maize genetic coefficients were calculated from the data in the above experiments. One method to recalculate genetic coefficients was to incrementally change the genetic coefficients until simulated matched observed results. Another method was performed according to the maize modeler's suggestion. The fitting method adequately established development genetic coefficients, whereas growth coefficients had similar biases as the original genetic coefficients. The explicit method did not well simulate maize growth. Using the fitted genetic coefficient means ± standard error, a sensitivity analysis was done. The genetic coefficient error that caused the greatest variation in simulated yield and aboveground biomass was identified. The most problematic genetic coefficients and associated model routines for yield and growth was the pod production relationship to nightlength in SOYGRO and juvenile phase duration in CERES-Maize

An Appraisal of Mass Media Role in Consolidating Democracy in Nigeria

The Nigerian media has been playing an active role in instituting democratic structures since the inception of the country as a nation state. The newspapers that were established during the early years of colonialism were used as potent tools of propagating the ideas of democracy in Nigeria. The various titles that appeared on Nigerian newsstands then were deployed to fight the colonial government. And through the instrumentality of the press, Nigeria achieved her independence in 1960. This study therefore critically assessed the performance of Nigerian mass media in consolidating democracy. The study is of the view that the mass contributed immensely to the return of democracy in Nigeria. This the media did through their critical criticism of the military juntas, mobilization of the citizens to participate in entrenching democratic values, exposing cases of corruption, and making public officers accountable to the people. Despite Nigerian media great performance in promoting democracy, they are faced with challenges which borders on issues of ethnicity, Lack of adequate modern communication gadgets, pressure from pressure groups and the government, ownership question, corruption, poor welfare and security issues among several others. For Nigerian media to serve as instrument for stabilizing democracy, they need to ensure that they live up to the ideals of the profession and deal with all cases of unethical practices among its members. The government on the other hand should truly support the noble profession by creating the right atmosphere for media men to operate without friction. Keywords: Communication, Democracy, Mass Media and Nigeri

Aza-nickelacycle key intermediate in nickel(0)-catalyzed transformation reactions

Oxidative cyclization of alkynes and imines with nickel(0) is a key step in multicomponent coupling and cycloaddition reactions to give nitrogen-containing organic compounds

N-Phosphine Oxide-Substituted Imidazolylidenes (PoxIms): Multifunctional Multipurpose Carbenes

This article discusses the concept of N-heterocyclic carbenes (NHCs) equipped with more than one functional moiety, which allows using these NHCs for multiple purposes. A pioneering example for such NHCs is N-phosphine oxide-substituted imidazolylidenes (PoxIms), and their synthesis and strategic use are highlighted. The utility of PoxIms by far exceeds the conventional use as multidentate ligands for metal complexes on account of the synergetic functions of the carbene and the N-phosphine oxide group(s).Hazra S., Hoshimoto Y., Ogoshi S.. N-Phosphine Oxide-Substituted Imidazolylidenes (PoxIms): Multifunctional Multipurpose Carbenes. Chemistry - A European Journal 23, 15238 (2017); https://doi.org/10.1002/chem.201703644

Rotation-Triggered Transmetalation on a Heterobimetallic Cu/Al N-Phosphine-Oxide-Substituted Imidazolylidene Complex

A novel strategy for the preparation of heterobimetallic N-heterocyclic carbene (NHC) complexes is demonstrated using N-phosphine-oxide-substituted imidazolylidenes (PoxIms). In these heterobimetallic Cu/Al complexes, the Cu and Al centers can be either completely separated or brought near each other via the rotation of the N-phosphinoyl group in the PoxIm ligands. Triggered by this rotation, transmetalation to exchange the Cu-OtBu and Al-C6F5 bonds occurs on in situ-generated Cu/Al PoxIm complexes, and the Cu-C6F5 and Al-OtBu bonds are formed in excellent yield. On the basis of the results of mechanistic studies, including the isolation/in situ observation of key complexes and theoretical calculations, a plausible reaction mechanism for an intramolecular transmetalation is proposed to proceed via an activation complex that includes the simultaneous coordination of the phosphinoyl oxygen atom to the Cu as well as the Al centers. Furthermore, the formation of carbon-carbon bonds between Al(C6F5)3 and allyl bromide mediated/catalyzed by Cu/Al PoxIm complexes is demonstrated. Upon the consecutive transfer of three C6F5 groups from a single molecule of Al(C6F5)3, allyl pentafluorobenzene derivatives were obtained. The present results demonstrate the role of phosphine oxide in the activation of organoaluminum reagents for the transmetalation between Cu(I) complexes bearing NHCs as well as the benefit of constructing an intramolecular system based on a heterobimetallic complex to achieve efficient transmetalation by programming the encounter of two organometallic fragments.Asada T., Hoshimoto Y., Ogoshi S.. Rotation-Triggered Transmetalation on a Heterobimetallic Cu/Al N-Phosphine-Oxide-Substituted Imidazolylidene Complex. Journal of the American Chemical Society 142, 9772 (2020); https://doi.org/10.1021/jacs.0c03252

CHF enhancement of a large heated surface by a honeycomb porous plate and a gridded metal structure in a saturated pool boiling of nanofluid

The enhancement of the critical heat flux (CHF) in saturated pool boiling of water-based nanofluid (containing TiO2 nanoparticles) by the attachment of a honeycomb porous plate (HPP) and a gridded metal structure (GMS) on a horizontal heated surface have been investigated experimentally. The honeycomb porous plate attached to the heated surface enhances the liquid supply due to capillary action to the heated surface and the release of vapor through the vapor escape channel. The deposition of nanoparticles on the heated surface during the boiling of the nanofluid enhances the spread of liquid along the heated surface due to the capillary action. The preceding papers by the present authors revealed that the CHF could be significantly enhanced by 2.2 times that of water boiling by the attachment of the HPP on the heated surface with the nanoparticle deposition layer. According to the hydrodynamic theory by Lienhard et al. (1973), the installation of a gridded structure on the heated surface could also enhance the CHF because the number of the escaping vapor jets each of which allows the liquid flow to the heated surface near the CHF conditions increases with the increment in the number of grid. The present paper describes the results directed toward the further enhancement of the pool boiling CHF of nanofluid by the installation of the GMS onto the HPP on a large heated surface. The tested surface has a diameter of ϕ50 mm, which is 20 times the capillary length, λC(=σ/g(ρl-ρv). For plain surfaces being larger than 20 times the length λC, the CHF can be regarded as being equivalent to that of an infinite large surface. Based on the Lienhard model, grid size of the GMS is chosen so that the CHF of water boiling is increased most effectively. As a result, for simultaneous existence of three factors (the HPP, the GMS and deposition layer of nanoparticles), the CHF has been enhanced to 3.1 MW/m2, which is the higher than either of the HPP in water, the HPP in water-based nanofluid and the GMS in water. High-speed-movie visualization of water boiling revealed that the attachment of the gridded metal structure shortens the hovering period of the coalesced bubble compared to the plain surface. Shortened period causes the more frequent liquid supply to the heated surface. These results illustrate the potential for increasing the safety margin in the IVR (In-Vessel Retention) systems as a heat removal technology