Wetting at the nanoscale

Wetting represents one of the most fundamental features of water interactions with a surface, resulting from interplay between cohesive and adhesive molecular forces. The wettability of a surface by a liquid is characterized by the contact angle of the liquid on that surface, which is also given by the well-known Young equation. At nanoscale, however, additional contributions enter the play and challenge the validity of the Young equation. We perform all-atom simulations of small water droplets and water films on flat surfaces with tunable polarities. The outcomes provide important insight into the relation between the surface chemistry and wettability, and imply the concept of generalized line tension. The latter stems from the three-phase contact line and represents a critical player in the stability of small droplets and liquid deposits in various contexts.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Vicerrectorado de Investigación de la UMA

Long-range correlations of the surface charge density between electrical media with flat and spherical interfaces

We study the asymptotic long-range behavior of the time-dependent correlation function of the surface charge density induced on the interface between two media of distinct dielectric functions which are in thermal equilibrium with one another as well as with the radiated electromagnetic field. We start with a short review which summarizes the results obtained by using quantum and classical descriptions of media, in both non-retarded and retarded regimes of particle interactions. The classical static result for the flat interface is rederived by using a combination of the microscopic linear response theory and the macroscopic method of electrostatic image charges. The method is then applied to the case of a spherically shaped interface between media.Comment: 6 pages, invited talk at the conference SCCS 2011, Budapes

The role of mineral phases in the biogas production technology

In the field of electric power industry, renewable energy sources, fertilisers, reclamation, and waste management, biomass is widely studied and used. Minerals are present in every step of biogas transformation, but their forms, occurrence, and composition have not been studied yet. However, there is no comprehensive study research that would address the presence of mineral phases in the process of biogas production. This aim of the study is determination of the amount and composition of the mineral phases present in fermentation residues resulting from different production technologies. Digestate mineral composition was analysed using 46 samples from agricultural biogas plants and university testing biogas reactor. The majority of samples contained the amorphous phase. Minority phases consisted of quartz, albite, orthoclase, muscovite, and amphibole. Opal-CT was found in eleven samples (1.26 to 12.1% wt.). The elements present in gas-liquid fluids or in liquids, gases and aerosols within the biogas technology system may create mineral phases, namely the amorphous phase or the crystalline phase under certain conditions. Opal-CT may enter the fermenter as part of plant tissues referred to as phytoliths, or as an unwanted admixture of different origin. It may also originate from the present amorphous SiO2.Web of Science251595

Attraction between Neutral Dielectrics Mediated by Multivalent Ions in an Asymmetric Ionic Fluid

We study the interaction between two neutral plane-parallel dielectric bodies in the presence of a highly asymmetric ionic fluid, containing multivalent as well as monovalent (salt) ions. Image charge interactions, due to dielectric discontinuities at the boundaries, as well as effects from ion confinement in the slit region between the surfaces are taken fully into account, leading to image-generated depletion attraction, ion correlation attraction and steric-like repulsive interactions. We investigate these effects by employing a combination of methods including explicit-ion and implicit-ion Monte-Carlo simulations, as well as an effective interaction potential analytical theory. The latter incorporates strong ion-image charge correlations, which develop in the presence of high valency ions in the mixture. We show that the implicit-ion simulations and the proposed analytical theory can describe the explicit simulation results on a qualitative level, while excellent quantitative agreement can be obtained for sufficiently large monovalent salt concentrations. The resultant attractive interaction between the neutral surfaces is shown to be significant, as compared with the usual van der Waals interactions between semi-infinite dielectrics, and can thus play a significant role at the nano scale.Comment: 9 pages, 4 figure

Optimization of a furniture factory layout

This paper deals with the problem of optimizing a factory floor layout in a Slovenian furniture factory. First, the current state of the manufacturing system is analyzed by constructing a discrete event simulation (DES) model that reflects the manufacturing processes. The company produces over 10,000 different products, and their manufacturing processes include approximately 30,000 subprocesses. Therefore, manually constructing a model to include every subprocess is not feasible. To overcome this problem, a method for automated model construction was developed to construct a DES model based on a selection of manufacturing orders and relevant subprocesses. The obtained simulation model provided insight into the manufacturing processes and enable easy modification of model parameters for optimizing the manufacturing processes. Finally, the optimization problem was solved: the total distance the products had to traverse between machines was minimized by devising an optimal machine layout. With the introduction of certain simplifications, the problem was best described as a quadratic assignment problem. A novel heuristic method based on force-directed graph drawing algorithms was developed. Optimizing the floor layout resulted in a significant reduction of total travel distance for the products

DUŠA, NJEZINI PUTEVI I STRANPUTICE, DRUŠTVENI NADZOR I KAPITALIZAM

Tekst uvodoma osvetli razmerje med telesom in „dušo“, pravzaprav duševnimi pojavi, saj te metafizične entitete ni niti v objektivnem niti v subjektivnem svetu – za razliko od konkretnega, nenehno spreminjajočega se toka zavestnih izkušenj (ki so za posameznika nekaj najbolj realnega, čeprav še vedno ne vemo, kako nastanejo in čemu služijo) –, za nameček pa je tudi ni mogoče utemeljiti ali pojasniti z evolucijsko teorijo. Duša (v svoji enoviti in nesmrtni formi), ki jo Bog podari le človeški „kroni stvarstva“, obstaja samo v religiozni perspektivi in torej kot „zgolj“ intersubjektivna, v kolektivni domišljiji in komunikaciji vzpostavljena in ohranjajoča se realnost, ki ima še vedno vse prej kot zanemarljiv vpliv na precejšnje število ljudi, in to ne le vernikov. Dognanja bioloških ved pa čedalje bolj rušijo tudi vero v obstoj svobodne volje in enega samega, nedeljivega in avtentičnega („resničnega“) jaza (sebstva), ki je v optiki liberalnega humanizma ultimativni vir smisla, ekonomskih odločitev ter estetskih, moralnih in političnih sodb. Osrednji del sestavljajo analize dojemanj človeške duševnosti in njihov vpliv na organizacijo družbenega nadzorstva, izvrševanje oblasti in upravičevanje hierarhij, ki so izvorno praviloma vselej namišljene, sčasoma pa postajajo vse bolj empirično otipljive in okostenele: kot zloslutne prerokbe, ki se uresničujejo same – dokler jih „oni in one spodaj“ (dozdevno manjvredni in običajno zapostavljeni, zatirani, izkoriščani, prezirani ali celo osovraženi subjekti) s političnim bojem ne postavijo pod vprašaj, kar se v zgodovini pripeti pomenljivo redko, zelo počasi in ne vedno uspešno. V zvezi s tem je posebna pozornost namenjena razgrnitvi in preučitvi različnih pomenov čustveno močno otovorjene besede „svoboda“. V sklepnem delu steče beseda o duševni motenosti in normalnosti, in sicer predvsem v povezavi z nasilnim vedenjem in različnimi načini soočanja posameznikov z „vse preveč človeškim“ problemom raznovrstnega trpljenja kot (po vsej verjetnosti neodpravljive) tegobe, ki te ne doleti le zaradi te ali one smole, zle usode ali nesrečne konstelacije zvezd in planetov, ampak že zgolj zato, ker si živ, ker si kot subjekt ujet v življenje – v neuspeh lastnega nerojstva – in z njim spete naravne mehanizme, na katere pa se vse prepogosto prilepi še kup družbeno, kulturno in medosebno generiranega gorja. Najbolj na kratko in karikirano rečeno: človeška eksistenca = duševna motnja. Ta težava se dandanes vse bolj „rešuje“ s kupovanjem komercialnih dobrin in storitev, ki obljubljajo doživljanje prijetnih občutkov (in eo ipso srečnost), in z uživanjem zdravil ali (zakonitih in nezakonitih) drog, ki neposredno spreminjajo posameznikov biokemični sistem. To pa ima več kot otipljive kriminogene učinke, saj je večina kriminalnega vedenja posredno ali neposredno povezana s posameznikovo težnjo po sreči (s hrepenenjem po prijetnih občutkih in netoleranco do neprijetnih občutkov).The article deals initially with the relationship between the body and the soul or rather mental phenomena, for the soul as a metaphysical entity does not exist in objective and subjective world (what does exist is the concrete, continually changing stream of subjective experiences being something that is the most real for every person, although modern science still cannot explain how our consciousness emerges from the brain and what are its biological functions). Moreover, the existence of eternal, individual, immortal soul cannot be explained with the Darwinian theory of evolution. The soul, as the exclusive gift given to the humans by the God, exists only in the religious perspective, i.e. as „solely“ intersubjective, in the collective imagination and communication established and reproduced reality, still influencing thoughts and actions of considerable number of people (not only believers). Results of contemporary life sciences shake and tear up also the belief in free will and existence of one single, individual, authentic (or „true“) self which is in the perspective of liberal humanism (as dominant ideology) the most important source of meaning, economic decisions, and moral, political and legal judgements. The central part of the article deals with various cultural „constructions“ of human mind and their influence on the organisation of social control, execution of power, and justifications of hierarchies (that are at first almost always imagined, but in the course of time they become more and more empirical and ossified: just as sinister self-fulfilling prophecies existing until they are not questioned by the political struggles of supposedly inferior, exploited, and oppressed human beings, that is by successful rebellions that are surprisingly quite rare historical events). In that regard, we pay special attention to various meanings of the emotionally much burdened word „freedom“ (or „liberty“). The final part of the article focuses on troubled, disturbed, pathological and normal mental phenomena, particularly in connection with violent behaviour and coping with the „all too human“ problem of divers forms of suffering, as (probably not abolishable) sorrow being not just the effect of some sort of bad luck, evil destiny or bad constellation of stars and planets, but of the bare fact that you are alive and as a subject captured in the live organism and its natural urges, needs and mechanisms. What is more, these inevitable sources of human suffering are accompanied by socially, culturally and interpersonally generated woe. Boldly put: human existence equals psychic troubles. Nowadays, people try to „solve“ this hard problem mainly by means of commercial (consumer) goods and services (that promise much desired experience of pleasant feelings and eo ipso happiness), and by medical and (legal and illegal) drugs that directly change biochemical system of individuals. Yet, that has considerable effects on crime. Namely, most criminal behaviour is directly or indirectly connected to the human aspiration after happiness, i.e. striving after pleasant feelings and intolerance to unpleasant ones.Einführend erläutert die vorliegende Arbeit die Beziehungen zwischen dem Körper und der „Seele“, beziehungsweise den seelischen Erscheinungen, weil sich die Seele, im Unterschied zu konkretem ständigem Ablauf bewusster Erfahrungen (die für den Einzelnen etwas Normales darstellen, obwohl man dessen Zweck noch nicht festgestellt hat), weder begründen noch mit Hilfe der Evolutionstheorie erklären lässt. Die Seele (in ihrer einheitlichen und unsterblichen Form), welche als Krone der Gottesschöpfung nur den Menschen geschenkt wurde, existiert nur in der Religion, beziehungsweise ausschlieβlich in der „intersubjektiven“ Form der kollektiven Phantasie und Kommunikation. Trotzdem übt die Seele einen wesentlichen Einfluss auf zahlreiche Menschen (auch Nichtgläubiger) aus. Naturwissenschaftler aber untergraben den Glauben an freien Willen und an ein einheitliches, unteilbares und authentisches Selbst (Wesen), welches im liberalen Humanismus die Quelle ultimativen Sinns, wirtschaftlicher Entscheidungen sowie auch ästhetischer, moralischer und politischer Ermessen darstellt. Im mittleren Teil der Arbeit wird die Auffassung der Geistigkeit und ihr Einfluss auf die Organisation sozialer Kontrolle, die Gewaltausübung und die Rechtfertigung der Hierarchien analysiert. Diese Hierarchien existieren am Anfang nur als Phantasien, aber mit Zeit werden sie immer mehr empirisch fassbar (und zwar als selbsterfüllende ominöse Prophezeiungen), bis sie von den Untergeordneten (scheinbar wenig wertvollen und gewöhnlich vernachlässigten, unterdrückten, ausgenutzten, verachteten oder auch verhaβten Einzelnen) durch politischen Kampf in Frage gestellt werden. In der Geschichte allerdings kam das nur selten vor und lief sehr langsam und nicht immer erfolgreich. Diesbezüglich legt man in der Arbeit besonderen Wert auf unterschiedliche Bedeutungen des emotional stark belasteten Wortes „Freiheit“. Abschlieβend werden in der Arbeit seelische Störungen und Normalzustände bearbeitet, vor allem bezüglich Gewaltverhaltens und unterschiedlicher Weisen der Auseinandersetzung des Einzelnen mit dieser Beschwerde, welche nicht nur wegen schlechten Schicksals, sondern bloβ wegen der Tatsache, dass man lebt, entsteht. Kurz gesagt ist menschliche Existenz gleich seelische Störung. Heutzutage setzt man sich mit diesem Problem durch das Kaufen komerzieller Güter und Dienstleistungen auseinander, was gute Gefühle (und eo ipso Glück) hervorruft. Andererseits wird diese Beschwerde durch den Konsum von Medikamenten und (legalen und illegalen) Drogen behandelt, was wiederum das biochemische System des Einzelnen verändert. Selbstverständlich hat das Auswirkungen auf das Strafrecht, weil kriminelles Verhalten mittelbar oder unmittelbar mit dem Streben des Einzelnen nach Glück (mit Sehnen nach angenehmen Gefühlen und Intoleranz unangenehmer Gefühle) verbunden ist.Il testo introduce alla riflessione sui rapporti tra il corpo e l’„anima“, o meglio gli stati dell’anima, posto che tale entità metafisica non esiste nel mondo oggettivo, né in quello soggettivo – a differenza del concreto, involontario mutevole corso delle esperienze coscienti (le quali per il soggetto sono qualcosa di più realistico, sebbene non sappiamo come sorgano e a che cosa servano). Non è nemmeno possibile basare o spiegare gli stati dell’animo fondandosi sulla teoria evolutiva. L’anima (nella sua forma unica ed immortale) donata agli umani da Dio, esiste soltanto in una prospettiva religiosa. Essa è unicamente „intersoggettiva“ nella fantasia collettiva nel dialogo con la realtà, benché abbia un’influenza affatto trascurabile su di un numero considerevole di persone – non solo credenti. Nondimeno, i dommatici delle scienze biologiche continuano ad incrinare la fede nell’esistenza di una volontà libera e di un indipendente, invisibile ed autentico (“reale“) io, il quale in un’ottica di umanesimo liberale rappresenta la fonte ultima del senso, delle decisioni economiche e dei giudizi estetici, morali e politici. La parte centrale del testo si compone dell’analisi della comprensione della spiritualità umana e della sua influenza sull’organizzazione del controllo sociale, sull’espressione del potere e sulla giustificazione delle gerarchie. Quest’ultime, di regola, sono sempre immaginarie, ma che col passare del tempo stanno diventando sempre più tangibili empiricamente e concrete, quali oscuri oracoli, che si realizzano di per sé – fino a quando „essi ed esse che si trovano sotto „(verosimilmente soggetti di valore inferiore e trascurati, usati, sfruttati o, addirittura, detestati) mediante la lotta politica non inizino a metterle in discussione. Ciò nella storia avviene molto raramente; molto lentamente e non sempre con successo. A tale riguardo, particolare attenzione viene dedicata alla scoperta ed allo studio dei differenti significati della parola - fortemente condizionata nell’aspetto emotivo - „libertà „. Nella parte conclusiva del lavoro si tratta dei disturbi mentali e della normalità e ciò principalmente con riguardo al comportamento violento ed ai diversi modi che i singoli hanno di confrontarsi con il problema „della troppo umana“ sopportazione, quale (probabilmente irreparabile) sofferenza, che non ti assale a causa di questa o quella sfortuna, della cattiva sorte o dell’avversa costellazione degli astri; ma soltanto perché sei vivo e perché come essere vivente – colto nell’insuccesso della non venuta al mondo – che seco porta i meccanismi naturali che solitamente vengono imputati a numerose sfortune sociali, culturali e interpersonali. Nel modo più breve e più eccessivo: l’esistenza umana = disturbo dell’anima. Tale sofferenza al giorno d’oggi si risolve sempre di più acquistando beni commerciali e servizi che promettono di vivere sensazioni piacevoli (e eo ipso la gioia) e consumando farmaci oppure stupefacenti (legali ed illegali), i quali direttamente mutano il sistema biochimico del soggetto. Ciò comporta effetti criminogeni più che tangibili, poiché la maggiore parte dei comportamenti criminali indirettamente o direttamente è collegata con la ricerca della felicità da parte del singolo (nella nostalgia delle sensazioni piacevoli e nella intolleranza delle sensazioni sgradevoli).Tekst uvodno osvjetljava odnose između tijela i „duše“, zapravo duševnih pojava, jer tog metafizičkog entiteta nema ni u objektivnom ni u subjektivnom svijetu – za razliku od konkretnog, nehotično mijenjajućeg toka svjesnih iskustava (koja su za pojedinca nešto najrealnije, iako se još uvijek ne zna kako nastaju i čemu služe), a nije ju moguće utemeljiti ili pojasniti niti pomoću evolucijske teorije. Duša (u svojoj jedinstvenoj i besmrtnoj formi), koju je Bog podario samo ljudskoj „kruni stvaranja“, postoji samo u religijskoj perspektivi odnosno kao „isključivo“ intersubjektivna, u kolektivnoj mašti i komunikaciji uspostavljena i održavana realnost, koja još uvijek ima nimalo zanemariv upliv na izniman broj ljudi, i to ne samo vjernika. Međutim, dogmatici bioloških znanosti i dalje sve više narušavaju vjeru u postojanje slobodne volje i jednog samostalnog, nedjeljivog i autentičnog („stvarnoga“) ja (sebstva), koji je u optici liberalnog humanizma ultimativni izvor smisla, ekonomskih odluka te estetskih, moralnih i političkih sudova. U središnjem dijelu rada analizira se shvaćanje ljudske duhovnosti i njegova utjecaja na organizaciju društvenog nadzora, izvršavanje vlasti i opravdavanje hijerarhija, koje su izvorno u pravilu uvijek zamišljene, no s vremenom postaju sve više empirijski opipljive i okoštale. Ona kao zloslutna proročanstva, ostvaruju se sama – dok ih „oni i one ispod“ (prividno manje vrijedni i obično zapostavljeni, ugnjetavani, iskorištavani, prezirani ili čak omraženi subjekti) političkom borbom ne dovedu u pitanje, što se u povijesti događa vrlo rijetko, jako polagano i ne uvijek uspješno. S tim u vezi, posebna je pozornost posvećena razotkrivanju i proučavanju različitih značenja emocionalno snažno opterećene riječi „sloboda“. U zaključnom dijelu riječ je o duševnim smetnjama i normalnosti, i to ponajprije u vezi s nasilnim ponašanjem i različitim načinima suočavanja pojedinaca s „i previše ljudskim“ problemom raznovrsnog trpljenja kao (po svoj vjerojatnosti nepopravljive) tegobe, koja ga ne zahvaća zbog ovog ili onog peha, zle sudbine ili nesretne konstelacije zvijezda i planeta, nego samo zato jer je živ, što je kao subjekt uhvaćen u život – u neuspjeh vlastitog nerođenja – i s njim povezane prirodne mehanizme za koje se često priljepljuje još gomila društveno, kulturno i međusobno generirane nesreće. Najkraće i najkarikiranije: ljudska egzistencija = duševna smetnja. Ta se tegoba danas sve više „rješava“ kupovanjem komercijalnih dobara i usluga koje obećavaju doživljavanje ugodnih osjećaja (i eo ipso sreću) i uživanjem lijekova ili (zakonitih i nezakonitih) droga, koje neposredno mijenjaju biokemijski sustav pojedinca. To ima više nego opipljive kriminogene učinke jer je većina kriminalnog ponašanja posredno ili neposredno povezana s težnjom pojedinca k sreći (s čežnjom prema ugodnim osjećajima i netolerancijom neugodnih osjećaja)