Determination of Ceres mass based on the most gravitationally efficient close encounters

Here is presented recalculated value of the mass of Ceres, based on explicit tracking of its gravitational influence on orbits evolution of 21 selected asteroids during their mutual close encounters (CE). It was applied a new modified method (MM) for mass determination, based on the connecting of pre-encounter observations to the orbit determined from post-encounter ones. The calculated weighted mean value of Ceres mass, based on modified method, is $(4.54\pm0.07)\,10^{-10}M_{\odot}$ while standard procedure (SM) provided result of $(4.70\pm0.04)\,10^{-10}M_{\odot}$. We found that correlation between individual estimated masses based on modified and standard method is 0.78, which confirms reliability of using modified method.Comment: MNRAS:Accepted 2011 September 28. Received 2011 September 28; in original form 2011 January 2

Meat consumption: theory, practice and future prospects

This research reviewed human meat consumption and highlighted associated history, challenges and benefits. Selected literature for the manuscript was from relevant titles and reliable international sources. From early times of the mankind meat consumption and animal husbandry were inseparable parts of living, and with similar consequences as dramatic influence on environment. Human need for meat consumption fueled development of large world markets with incredible trade, processing and consumption. This overconsumption has caused health problems associated with high intake of cholesterol and sodium chloride. Another problem with meat consumption is the use of additives in processed products. In modern time these problems are tackled by the use of additives from plants that have health benefits. Thermal processing is yet another problem with meat consumption that food industry and science addresses by non-thermal replacements (e. g. high-pressure processing and electrotechnologies). Recently, interesting alternatives for meat processing included 3D Printing that is able to engineer admirable meat products from by-products. However, this technology might need to employ enzymes such as transglutaminase, associated with potential health problems and misleading the customers. Unfortunately, fraudulent activities are common for meat products and it would be prudent to organize enforcement centers with at least police and analysts skilled in chemometrics and various laboratory techniques for food defense. It seems as humankind expands it will seek more proteins from plant, insects, unicellular biomass, and synthetic meat than from the animal origin, however all of the alternatives must be carefully evaluated against consumer acceptance, public health and environmental concerns

Geometry of Molecules. Part 4. Iterative Maximum Overlap Calculations of lnteratomic Distances, Bond Angles and Strain Energies in Some Rotanes and Related Spiro-Compounds

The iterative maximum overlap approximation (IMOA) is applied to a series of [n]-rotanes and some related spiro-compounds of unusual topology. The properties of these molecules were discussed in terms of the local hybrid orbitals and extent of their overlapping. Necessity of a clear distinction between bond length and interatomic distance in strained systems is pointed out. Considerableshortening of the C-C interatomic distance of the central carbocycles in [n]-rotanes was established. It was rationalized by the bent bond concept. The delocalization of the pseudo-pi electrons around the central ring in [n]-rotanes is briefly discussed. Angular strain energy and its distribution over the molecular fragments was quantitatively considered in the studied compounds. The strain and heat of formation of spiro (3.3) heptane are favourably compared with available ab initio results

The Action of Hydrazines upon \u27Thiazolidine-4-carboxylic Acids I. Preparation of D-Penicillamine from D-Benzylpenilloic Acid

In the reaction of phenylhydrazine with n-benzylpenilloic acids (Ia or Ila) n-penicillamine was obtained in high yield and purity. The lack of reactivity of N-acyl derivatives (Ib or Ub) with phenylhydrazine indicated that the above reaction proceeded through the open chain imine tautomer of Ia or Ila (IV). The epim~risation of n-benzylpenilloic acid (Ia and Ha) in aprotic solvents was studied by using PMR spectroscopy

Geometry of Molecules. Part 4. Iterative Maximum Overlap Calculations of lnteratomic Distances, Bond Angles and Strain Energies in Some Rotanes and Related Spiro-Compounds

The iterative maximum overlap approximation (IMOA) is applied to a series of [n]-rotanes and some related spiro-compounds of unusual topology. The properties of these molecules were discussed in terms of the local hybrid orbitals and extent of their overlapping. Necessity of a clear distinction between bond length and interatomic distance in strained systems is pointed out. Considerableshortening of the C-C interatomic distance of the central carbocycles in [n]-rotanes was established. It was rationalized by the bent bond concept. The delocalization of the pseudo-pi electrons around the central ring in [n]-rotanes is briefly discussed. Angular strain energy and its distribution over the molecular fragments was quantitatively considered in the studied compounds. The strain and heat of formation of spiro (3.3) heptane are favourably compared with available ab initio results

Ring Expansion of Thiazolidine and Nucleophilic Substitution in N-Acyl Derivatives of 6-Thia-3,8-diazabicyclo[3.2.1. ]octan-2-one

Reaction of N3,N8-diacyl 6-thia-3,8-diazabicyclo/3.2. l./octan-2- -one (I) with PC15 or S02Cl2 gave 6-chloro substituted N2,N5-diacyl 7-thia-2,5-diazabicyclo/2.2.2./octan-3-one (II). Treatment of II with water yielded the 6-hydroxy derivative (III) while reaction with methanol gave the 6-methoxy derivative (IV). Under the same reaction conditions the mono N8-acyl derivative (V) gave a mixture of 6-substituted 7-thia-2,5-diazabicyclo/2.2.2./octan-3-one and 4- -su bsti tuted 6-thia-3,8-diazabicyclo/3.2. l ./octan-2-one derivatives (XIV and XV; VI and VII; VIII and IX). It was proposed that ring expansion of thiazolidine and nucleophilic substitution occured vi a the thiiranium ion XIII as a common intermediate

Formation of Isopenillic Acid Derivatives in the Reaction of Benzylpenicillin with Phosphorus Pentachloride

Treatment of benzylpenicillin ester (I) with phosphorus pentachloride at 60 °c gives a mixture of benzylisopenillic acid ester (II) and its disulphide (Ill). Under the same reaction conditions, 6- -phthalimidopenicillinate ester (V) yields a-methyl 6-phthalimido- · penicilloate ester (VIII)

Hermite-Gaussian Expansion of Hydrogenic Orbitals

Hydrogen ls, 2s, 2p, 3s, 3p, 3d, 4s, 4p and 4d (HO) orbitals are expanded in series of Hermite-Gaussian (HG) functions. Adjustable parameters are determined by the integral least-square fit procedure. HG approximation of the fourth degree (HG4) proved particularly good and useful in representing hydrogen AOs. It yields hydrogen (and hydrogen-Iike) orbitals which are more accurately described than the corresponding GTO expansion. Hydrogen type orbitals (HTO) expressed in HG4 bases could be useful in molecular calculations involving heavier atoms because some STO orbi ta ls do not perform well for higher principal quantum numbers. Use of STOs for inner-shells and HOs for outer valence shell electrons in heavy atoms might be advantageous. Both types of atomic orbitals could be well represented by HG functions. HG representation of polarization functions, which play an important role in describing charge redistribution upon formation of chemical bonds and are crucial in treating anions, might be useful too. The HG functions may also serve a purpose in solving the Schrodinger equation in momentum representation and in calculations of the X-ray scattering factors

Preparation and lsomerization of 3S-Benzylpenicilloamides

The isomerization of 3S-benzylpenicillobenzylamide in aprotic solvents was studied by using 1H NMR spectroscopy. The lack of isomerization of the N-acetyl derivative of I indicated that the epimerization at C-5 and C-6 positipn2 proceeded through the open chain imine tautomer (III) of I or II. Since the isomerization at the C-6 position occurred after the opening of the thiazolidine ring, it was concluded that isomerization at this centre preceeded through penamaldic acid (IV) as an intermediate. All four isomers· of 3S- benzylpenicillobenzylamide were prepared and isolated as methyl esters (II)