The bio-ethanol production with the thin stillage recirculation

In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield) was 97.96 %, which implicates that the experiment conditions were chosen and performed well. With the addition of the thin stillage, the bioethanol yield increased and was above 100 %. Higher bioethanol yield than 100 % can be explained by the fact that the thin stillage contains carbohydrates, amino acids and yeast cells degradation products. The bioethanol yield increased with the increased number of thin stillage recirculation cycles. Dry matter content in fermenting slurry increased with the increased thin stillage quantity and the number of the thin stillage recirculation cycles (8.04 % for the first and 9.40 % for the sixth cycle). Dry matter content in thin stillage increased with the increased thin stillage quantity and the number of thin stillage recirculation cycles. Based on the obtained results it can be concluded that thin stillage recirculation increased the bioethanol yield. The highest bioethanol yields were obtained with recirculation of 10% thin stillage

A METHOD FOR DETERMINATION OF SEPARATION PROPERTIES OF MEMBRANES

In this study, design of lab scale device for determination of separation properties of membranes is presented and analyzed. Device operates with different gas pressure between chambers, whereby gas streams perpendicular to the membrane. Using appropriate acquisition system and applying mathematical formulas, mechanism for gas transfer through the membrane is determinate. Polymer membranes based on zeolite are synthesized and tested by lab scale device. The membranes with various content of zeolite are tested with CO 2  gas until optimal composition of membrane components is established. Beside good mechanical and structural properties of applied membrane, suitable values of permeability with good agreement with the literature data are obtained

Threshold Laws for the Break-up of Atomic Particles into Several Charged Fragments

The processes with three or more charged particles in the final state exhibit particular threshold behavior, as inferred by the famous Wannier law for (2e + ion) system. We formulate a general solution which determines the threshold behavior of the cross section for multiple fragmentation. Applications to several systems of particular importance with three, four and five leptons (electrons and positrons) in the field of charged core; and two pairs of identical particles with opposite charges are presented. New threshold exponents for these systems are predicted, while some previously suggested threshold laws are revised.Comment: 40 pages, Revtex, scheduled for the July issue of Phys.Rev.A (1998

Lightweight Interactions for Reciprocal Cooperation in a Social Network Game

The construction of reciprocal relationships requires cooperative interactions during the initial meetings. However, cooperative behavior with strangers is risky because the strangers may be exploiters. In this study, we show that people increase the likelihood of cooperativeness of strangers by using lightweight non-risky interactions in risky situations based on the analysis of a social network game (SNG). They can construct reciprocal relationships in this manner. The interactions involve low-cost signaling because they are not generated at any cost to the senders and recipients. Theoretical studies show that low-cost signals are not guaranteed to be reliable because the low-cost signals from senders can lie at any time. However, people used low-cost signals to construct reciprocal relationships in an SNG, which suggests the existence of mechanisms for generating reliable, low-cost signals in human evolution.Comment: 13 pages, 2 figure

If cooperation is likely punish mildly: Insights from economic experiments based on the snowdrift game

Punishment may deter antisocial behavior. Yet to punish is costly, and the costs often do not offset the gains that are due to elevated levels of cooperation. However, the effectiveness of punishment depends not only on how costly it is, but also on the circumstances defining the social dilemma. Using the snowdrift game as the basis, we have conducted a series of economic experiments to determine whether severe punishment is more effective than mild punishment. We have observed that severe punishment is not necessarily more effective, even if the cost of punishment is identical in both cases. The benefits of severe punishment become evident only under extremely adverse conditions, when to cooperate is highly improbable in the absence of sanctions. If cooperation is likely, mild punishment is not less effective and leads to higher average payoffs, and is thus the much preferred alternative. Presented results suggest that the positive effects of punishment stem not only from imposed fines, but may also have a psychological background. Small fines can do wonders in motivating us to chose cooperation over defection, but without the paralyzing effect that may be brought about by large fines. The later should be utilized only when absolutely necessary.Comment: 15 pages, 6 figures; accepted for publication in PLoS ON

Операторы da, pour и то в градуальных телеономических глагольных конструкциях в сербском, английском и французском языках

This paper examines how the Serbian “da” subordinate clause, the French preposition pour and the English particle to, mainly used in clauses expressing purpose, can become linguistic forms expressing temporal and oppositional values. In other words, it represents an original analysis of what we call non / pseudo-teleonomic clauses in Serbian, French and English. It examines the similarities and differences between the three languages and shows that the “da” subordinate clause in Serbian has a much more extensive scope than pour in French, which in turn has wider applications than to in English. The study is illustrated by concrete and genuine examples primarily drawn from the press in the three languages. It aims at reaching generalization via the principle of continuum which makes it possible to tackle teleonomic vs pseudo-teleonomic issues not in terms of binary opposition but in terms of gradience.В настоящей работе на материале трех с синтаксической и морфологической точки зрения разных языков рассмотрены присущие им псевдотелеономические и нетелеономические глагольные конструкции, а именно: особый тип придаточных предложений, вводимых союзом да (что) в сербском, конструкции с оператором to в английском и конструкции с предлогом pour во французском языке. Иными словами, проанализировано, каким образом союз да в сочетании с сослагательным наклонением (потенциалом) в сербском, предлог pour во французком и частица to глийском, используемые в основном для выражения намерения, могут быть употреблены также для выражения и темпоральности, и оппозиции. При анализе сходств и различий между данными структурами на материале аутентичных примеров из прессы обнаружено, что во всех трех языках существует семантико-прагматический континуум, внутри которого распространяются их значения. Ядро этого континуума составляет телеономичность как прототипическое и наиболее распространенное значение. За телеономичностью следуют случаи, именуемые в статье псевдотелеономическими, в которых с помощью данных структур устанавливается темпоральная последовательность событий в прошлом: событие из подчиненного предложения (в работе обозначено как E2) является не виртуальной целью подлежащего сочиненного предложения, а конкретным прошлым событием, которое представляет собой ожидаемое логичное разрешение выраженной ситуации (события E1). На периферии спектра находятся примеры, именуемые нетелеономическими, в которых с помощью перечисленных операторов вводятся уступительные предложения. Ширина данного спектра является различной в анализируемых языках. Исследование показало, что союз да имеет самый широкий объем, в то время как частица to имеет самый узкий объем.У овом раду смо, посматрајући три, у синтаксичком и морфолошком погледу, различита језика, испитали псеудотелеономичне и нетелеономичне глаголске конструкције које се у њима јављају: у српском језику као посебна врста зависних клауза уведених везником да, енглеском са оператoром to и у француском са предлогом pour. Другим речима, анализирали смо како везник да (праћен потенцијалом) у српском, предлог pour у француском и партикула to у енглеском, који се претежно користе за исказивање намере, могу да се употребе да искажу како темпоралност тако и опозицију. Испитујући сличности и разлике између ових структура на аутентичним примерима ексцерпираним из штампе, уочили смо да у сва три дата језика постоји семантичко-прагматички континуум дуж кога се протежу њихова значења. На почетку тог континуума налази се телеономичност као прототипично и најчешће значење. За њом следе случајеви које смо назвали псеудотелеономичним а у којима се посматраним структурама успоставља темпорални редослед догађаја у прошлости: догађај из зависне клаузе (у раду означен као Е2) овде није виртуелни циљ субјекта независне клаузе, већ конкретан прошли догађај који представља очекивано и логично разрешење исказане ситуације, односно догађаја Е1. На самом крају спектра јављају се примери које смо назвали нетелеономичним, а у којима посматрани оператори уводе допусне клаузе. Ширина овог спектра се, међутим, разликује од језика до језика: наше истраживање је показало да везник да има најобимнији опсег, а партикула to најужи

Topological enslavement in evolutionary games on correlated multiplex networks

Governments and enterprises strongly rely on incentives to generate favorable outcomes from social and strategic interactions between individuals. The incentives are usually modeled by payoffs in evolutionary games, such as the prisoner's dilemma or the harmony game, with imitation dynamics. Adjusting the incentives by changing the payoff parameters can favor cooperation, as found in the harmony game, over defection, which prevails in the prisoner's dilemma. Here, we show that this is not always the case if individuals engage in strategic interactions in multiple domains. In particular, we investigate evolutionary games on multiplex networks where individuals obtain an aggregate payoff. We explicitly control the strength of degree correlations between nodes in the different layers of the multiplex. We find that if the multiplex is composed of many layers and degree correlations are strong, the topology of the system enslaves the dynamics and the final outcome, cooperation or defection, becomes independent of the payoff parameters. The fate of the system is then determined by the initial conditions

Human behavior in Prisoner's Dilemma experiments suppresses network reciprocity

During the last few years, much research has been devoted to strategic interactions on complex networks. In this context, the Prisoner's Dilemma has become a paradigmatic model, and it has been established that imitative evolutionary dynamics lead to very different outcomes depending on the details of the network. We here report that when one takes into account the real behavior of people observed in the experiments, both at the mean-field level and on utterly different networks the observed level of cooperation is the same. We thus show that when human subjects interact in an heterogeneous mix including cooperators, defectors and moody conditional cooperators, the structure of the population does not promote or inhibit cooperation with respect to a well mixed population.Comment: 5 Pages including 4 figures. Submitted for publicatio

Bloggers Behavior and Emergent Communities in Blog Space

Interactions between users in cyberspace may lead to phenomena different from those observed in common social networks. Here we analyse large data sets about users and Blogs which they write and comment, mapped onto a bipartite graph. In such enlarged Blog space we trace user activity over time, which results in robust temporal patterns of user--Blog behavior and the emergence of communities. With the spectral methods applied to the projection on weighted user network we detect clusters of users related to their common interests and habits. Our results suggest that different mechanisms may play the role in the case of very popular Blogs. Our analysis makes a suitable basis for theoretical modeling of the evolution of cyber communities and for practical study of the data, in particular for an efficient search of interesting Blog clusters and further retrieval of their contents by text analysis

L-arginine reduces tubular cell injury in acute post-ischaemic renal failure

Background. The pathophysiology of renal ischaemia, resulting in tubular cell injury and leading to acute renal failure (ARF), remains unclear. An ever-increasing number of investigations focus on a possible role of nitric oxide (NO) in regulating circulation during ARF. In this context, we investigated the influence of chronic stimulation or inhibition of NO synthesis, or both, on haemodynamic parameters, histology and plasma renin activity (PRA) after ischaemia-reperfusion injury of rat kidneys. Methods, Experiments were performed on adult, male Wistar rats. Before induction of ARF, a group of animals was treated with a NO synthesis inhibitor (L-NAME) and another group was treated with a precursor of NO synthesis (L-arginine). The animals received those substances for 4 weeks. Control groups received the same amount of tap water for 4 or 8 weeks and were divided into groups with ARF (4 weeks-ARF group and 8 weeks-ARF group) and a sham-operated group. Another group of rats was treated first with L-NAME and then with L-arginine in their drinking water, for 4 weeks for each of these two substances. All parameters were evaluated 24 h after the induction of ischaemic ARF or the sham operation. Results, Our results show that such long-term stimulation of NO release by L-arginine improved renal haemodynamics in the ischaemic form of ARF. Renal blood Bow (RBF) increased by 96% in the L-arginine-treated rats with ARF compared with the group with ARF alone. Inhibition of NO synthesis worsens renal haemodynamics after ARF. However, this aggravation can be reversed by L-arginine. The rate of water reabsorption was reduced in all groups with ARF, but this reduction was least in the group treated with L-arginine. The rate of Na+ reabsorption was reduced in all groups 24 h after renal ischaemia, but a significant decrease was observed after the inhibition of NO synthesis. Histological examination of the kidney specimens showed that morphological changes were least in the rats treated with L-arginine, when compared with all other groups with ARF. Nevertheless, the lesions were most prominent in the L-NAME + ARF group. In this group, the areas of corticomedullar necrosis were more widespread in comparison with other groups, especially the L-arginine group where only swelling of the proximal tubular cells was observed. Treatment with L-NAME was not accompanied by any significant alteration in the plasma concentration of angiotensin I (ANG I), while in the group treated with L-arginine ANG I had a tendency to decrease. Conclusions. Acute post-ischaemic renal failure may be alleviated by administering the NO substrate (L-arginine). NO acts cytoprotectively on tubular epithelial cells in ischaemia-reperfusion injury of rat kidney. Evidence of this comes from both histopathological findings and increased tubular water and sodium reabsorption. However, inhibition of NO synthesis (provoked by L-NAME) worsens renal haemodynamics and aggravates morphological changes after ARF. These aggravations can, however, be reversed by L-arginine