How to Write Well

Iako se pretpostavlja da je svaki znanstvenik barem funkcionalno pismen, mora se priznati da malo naših znanstvenika dobro i s lakoćom piše – stoga i potreba za ovim člankom. Postupak pisanja podijeljen je na tri faze (priprema, pisanje i redigiranje). U fazi pripreme nužno je doživjeti budući tekst kao organsku cjelinu (treba naučiti misliti sintetički). U fazi pisanja najvažnije je usredotočiti se na redoslijed izlaganja (kompoziciju). Redigirati treba tako da se autor u svakom čitanju bavi samo jednim zadatkom (nadopunama, provjerama, stilskim dotjerivanjem, usklađivanjem s gramatičkim i pravopisnim normama itd.). Također su dani primjeri lošeg prevođenja s engleskog jezika te primjeri dorade teksta.In spite of a popular belief that every scientist knows how to write a professional paper, it is a sad fact that only a few scientists are really good writers. Hence the need for this paper. The process of writing is divided in three general steps (preparing, writing, and editing). In the first step, it is necessary to comprehend the future text as the whole. In the next step, one has to deal with its composition. In the third step, it is important to divide editing in precisely defined actions (adding and checking data, grammatical and stylistic corrections, spell–checking). The article also addresses certain differences between English and Croatian related to the meaning of words of Latin origin and provides examples of stylistic editing of scientific texts

How to Master Speech Delivery

Govorničko umijeće, vještina javnog nastupa stara je vještina koje se osobito njegovala među Grcima i Rimljanima. No unatoč modernim vremenima, obilju znanstvenih knjiga, časopisa i kompjutoriziranih baza podataka, bez govorničkog umijeća ne može ni moderni znanstvenik. Nakon kratkoga povijesnog pregleda, autor nas uči kako da pripremimo stručno predavanje u pet koraka (quidditas, compositio, eloquentio, recapitulatio, actio), upozoravajući na najbolja rješenja i česte pogreške. Članak sadržava i tablicu najčešćih jezičnih i tipografskih pogrešaka koje se susreću u stručnoj literaturi i govoru.Rhetoric, a very popular skill among ancient Greeks and Romans, has become nearly extinct among the modern scientists, mainly due to the abundance of inexpensive textbooks, scientific journals and computers. With this article the author intends to fill the gap in the education of Croatian scientific community by presenting the basics of rhetoric, particularly its application in delivering scientific lectures. This article addresses the classical five-step scheme for preparing a speech (quidditas, compositio, eloquentio, recapitulatio, and actio) and comments on the most frequent errors observed in practice. These are further illustrated in a table listing the most frequent typographic and speech errors and their correct forms

Molecular Mechanics Calculations on a New Model Compound Cu(II)-Zn(H)-Superoxide Dismutase

The X-ray structure of a new model compound of Cu(II)-Zn(II)-super- oxide dismutase, [N,N-butylenebis(2-acetylpyridineiminato)]copper(II) perchlorate was subjected to molecular mechanics calculations in order to reproduce the shape of the copper(II) coordination polyhedron. Altogether, six force fields were used; three of them yielded good agreement between theory and experiment, the rest gave structures highly distorted from planarity. The results suggest inadequacy of some molecular mechanics models for the simulation of highly distorted structures

Iterative Method for Finding Low-Energy Conformations Based on the Model of Overlapping Spheres: Application to Alkanes

A new approximate function for estimation of conformational potential from the excluded volume inside the sphere centered at the geometrical centre of molecule (model of overlapping spheres) is proposed. The value of the function was successfully correlated with the conformational energies of six simple alkanes (from butane to isoheptane). The iterative procedure based on the minimisation of excluded volume is discussed. The method was checked on n-decane and five of its branched derivatives (up to C18H38). The method appears to be very efficient in finding the low-energy conformations of normal alkanes but, for branched molecules, it yielded conformations of higher energy in some cases. The method can be regarded as a simple and fast procedure for finding lowenergy conformations

Ante Graovac – Life and Works

Ivan Gutman, Biserka Pokrić, Damir Vukičević (Eds.) Ante Graovac – Life and Works Mathematical Chemistry Monographs, Vol. 16 Faculty of Science, University of Kragujevac, Kragujevac (Serbia), 2014 306 + IV pages ◦ ISBN 978-86-6009-021-0 This work is licensed under a Creative Commons Attribution 4.0 International License

Procjena konstanti stabilnosti bakrovih(II) kelata s aminokiselinama metodom preklapanja kugli

The method of overlapping spheres (OS) was applied to the estimation of stability constants of mono- (log β110) and bis-complexes (log β120) of α-amino acids and their N-alkyl and N,Ndialkyl derivatives with copper(II). The central sphere, with a 0.3 or 0.4 nm radius, was placed at the central (Cu), equatorial (N) or apical (X) position of the coordination polyhedron. The overlapping volume of the central sphere and the van der Waals spheres of neighbouring atoms was calculated and correlated with the measured stability constants. The training set (N = 11) consisted of four naturally occurring amino acids and seven N-alkylated and N,N dialkylated glycines. It gave, upon linear regression of stability constants on the overlapping volume, correlation coefficients (r) of 0.944 and 0.895 for log β110 and log β120, respectively. The best regressions (r = 0.977–0.998) were obtained by taking into account only the complexes of N-alkylated glycine (N = 5) and placing the central sphere at the position of equatorial nitrogen atom(s). Using the regression functions derived from the training set, it was possible to estimate the measured stability constants with an error in the range 0.1–0.5 log β units.Metoda preklapanja kugli (overlapping spheres, OS) primijenjena je za procjenu konstanti stabilnosti mono-kompleksa (log β110) i bis-kompleksa (log β120) α-aminokiselina i njihovih N-alikiliranih i N,N-dialikiliranih derivata s bakrom(II). Središnja kugla, radijusa 0,3 ili 0,4 nm, postavljena je u središnji (Cu), ekvatorijalni (N) ili apikalni (X) položaj koordinacijskoga poliedra. Izračunan je volumen preklapanja središnje kugle i van der Waalsovih kugli okolnih atoma te je zatim koreliran s izmjerenim konstantama stabilnosti. Temeljni skup (N = 11) sastojao se od četiri prirodne aminokiseline i sedam N-alikiliranih i N,N-dialkiliranih glicina. Linearnom regresijom konstanti stabilnosti prema volumenu preklapanja postignut je iz temeljnog skupa koeficijent korelacije (r) u iznosu od 0,944 za log β110 i 0,895 za log β120. Najbolje regresije (r = 0,977–0,998) dobivene su iz podataka samo za N-alkilirane glicine (N = 5), pri čemu se središnja kugla nalazila na ekvatorijalnome (dušikovome) atomu ili atomima. Iz regresijskih funkcija razvijenih na temeljnome skupu izračunane su konstante stabilnosti koje su se od izmjerenih vrijednosti razlikovale za 0,1 do 0,5 log β jedinic

An Analysis of the Shape of the Coordination Polyhedron of Pentacoordinated Copper(II) Chelates with N-Alkylated Amino Acids

An analysis of eight pentacoordinated (aqua) copper(II) chelates with N-alkylated amino acids revealed that they could be separated in two group s with respect to the shape of their coordination polyhedra. Group I, consisting of N,N-dimethylated derivatives, can be described as distorted square pyramids with a pseudo C4v symmetry. Group II, consisting of other N-alkylated and N,N-dialkylated derivatives, can be described as square pyramids distorted towards the trigonal pyramid along the axis O-Cu-O\u27 = 180°. The apical bond length (Cu-OH2) correlates extremely well on the NCu- N\u27 angle tr = 0.9996) for the group I molecules and sub stantially less well for group II (r = 0.954). Multiple regression of experimental apical lengths on the N-Cu-N\u27 angle and the absolute difference IN-Cu-N\u27 - O-Cu-O\u27I yields IRI= 0.981 for N = 8. By applying the different measures of distortion of the copper(II) coordination polyhedron, it was possible to predict the apical bond length from the structures obtained by molecular mechanics calculations with the minimum value for the root-mean-square deviation between experiment and the ory 0.083 A (group I), 0.032 A (group II) and 0.068 A (both groups)