Synchronous and Sequential Strategies in the Process Design of Cascade Equipment

Cascade or multistage equipment is characterized by the repetition of similar equipment elements in series. Process design, resulting into the main geometric and kinematic dimensions of the equipment, makes use of different strategies. These strategies, based on a process description, the (equality- and inequality) constraints and the number of degrees of freedom of the mathematical system, which describes the process, can be divided in synchronous- and sequential procedures. In a synchronous strategy no a priori requirements are made as to the distribution of a given process variable over the stages, so that the equipment dimensions are obtained simultaneously. In contrast to this a sequential strategy makes use of a priori statements resulting into stage-to-stage calculations and a decreasing number of degrees of freedom. The general theory presented with detailed information on process description, constraints and degrees of freedom, has been applied to the process design of a multi-stage centrifugal compressor

Vertical Co-ordanitaion in Transition Agriculture: a Hungarian Cooperative Case Study

The agriculture is traditional risky business, but in transition countries agricultural producers should face some additional difficulties. The agri-food chains are still suffering from underdeveloped market institutions creating severe barriers for price discovery and high transaction costs to co-ordinate market exchanges. Co-operatives are usually neglected as a possible governance structure in recent empirical analyses. This study analyzes the advantages and limitations of cooperatives for establishing an appropriate vertical coordination forms in the framework of transaction cost economics. We present a case study to show that at the recent stage of development in Hungarian agriculture co-operatives can solve some problems arising from missing and embryonic market institutions. We argue that the co-operative is a good example, how an agricultural co-operative can achieve some of the potential advantages, solving many “traditional” TCE and agency problems and serving its members with a continuing growth.

A gyökfogó dokozahexaénsav mint agyvédő = Docosahexaenoic acid (DHA) as a free radical scavenger brain protector

Telítetlen zsírsavak (PUFA) fontos szerepet játszanak mint antioxidánsok az emberi testben, különös tekintettel az agyban. Lipidek szisztematikus számítási vizsgálatait az OTKA támogatás előtt már elkezdtük. A támogatás alatt 4 fő tématerületen értünk el eredményeket: Téma 1: Molekuláris konformció változások termodinamikai alapjai Egyszerű szerves molekulák, mint különböző szénhidrogén származékok, peptidek, folytonos termodinamikai fügvényeit állítottuk elő konformációs mozgások mentén. Téma 2: Zsirsavak konformációs információ Igazoltuk a PUFA-k flexibilátásbeli hasonlóságát a peptidekhez a potenciál felületek hasonlóságával. DHA a legfontosabb képviselője a PUFA családnak. Téma 3: Foszfolipidek konformációs információi Az első két téma eredmnyeinek felhasználásával egyszerű foszfolipid modelleket konstruáltunk. A két zsirsavlánc relativ helyzte, kölcsönhatásai, membránszerű elrendeződés esetén állt vizsgálataink homlokterében. Téma4 Szabadgyökök reakciói PUFA és PUFA modellekkel Szabadgyökök és reakcióik PUFA-val lipidek kettősrétegeiben biológiailag nagyon fontos folyamatok. Az E vitamin az egyik leghatékonyabb gyökfogó membránokban. A PUFA-kban mindig megtalálható allil-C-H kötések és különböző típusú gyökök reakcióinak kiterjedt vizsgálata folyt. | Polyunsaturated fatty acids (PUFA) play an important role as an antioxidant in the whole human body but more specifically in the brain. The overall project had 4 Topics: Topic 1 Fundamental Thermodynamics of Molecular Conformational Changes: Simple organic molecules were investigated in computing continues thermodynamic functions along conformational changes. These included a variety of compounds from hydrocarbons to peptides. Topic 2 Conformational information of fatty acid: Interestingly enough their felxibility was similar to that of peptides as could be judged from the similarity of their conformational potential energy surfaces. Topic 3 Conformational information of phospholipids: The results and experience obtained from the first two topics were used to construct simple phospholipids. The relative orientations of the two fatty acids in a phospholipid had to be studied to see if the nearly parallel arrangement within the lipid bilayer is enforced by nearest neighbour interaction or if such a geometry is an intrinsically stable structure. Topic 4 Free radical reactions with PUFA and PUFA models: Free radicals and their reactions with PUFA within the lipid bilayer are a biologically very important reactions. The generation of free radicals and their transformation as well as their reactions with allylic C-H bonds, which are always present is PUFA, has been studied in details

Contractual relationships in the Hungarian milk sector

In this paper we present an empirical analysis of farmers' contracting choice in the Hungarian milk sector using 2005 milk producer survey data, employing transaction cost economics. We focus on analysing some key determinants of farmers' contracting choices: type of contracts, duration, number of contractors, incentives provided in the contract and business history of farmers and buyers. Some of the main results include the importance and effect of farm size, quantity of milk delivered, planned short and long run or contract related investment on farm, the possibility of farmer to influence prices on the contracting choices. --transaction costs,contracts,milk products,Hungary

The Choice of Marketing Cooperative in a Transition Agriculture

The agriculture in transition countries can be described by considerable uncertainties. In these countries public institutions are ineffective in ensuring contract enforcement. The absence of enforceable contract to set up any kind of vertical co-ordination has become difficult. In addition, this creates severe barriers for price discovery involving high transaction costs to co-ordinate market exchanges. Although there is a wealth of literature on marketing cooperative, but research on their role in transition agriculture is scarce. This paper tries to contribute to this gap. In this paper we have analysed the potential benefits and costs of the marketing cooperatives in Hungary employing transaction cost economics framework. The results presented add to a small literature on the marketing cooperatives in transition agriculture. We found that the quantity, the existence of contract, flexibility and trust are the most important factor for farmers to selling their product via cooperative. The cluster analysis provides some additional insights regarding farmers' choices. Namely, direct benefits including price, input finance extension services and speed of payments from cooperative membership have also important role. The most striking result is that the diversification and reputation has positive influences on the share of cooperative. Furthermore, large farmers have less willingness to sell their product to the cooperative. Surprisingly, asset specificity has rather negative effects on the share of cooperative.Agribusiness,

THE IMPACT OF TRUST ON COOPERATIVE MEMBERSHIP PERFORMANCE AND SATISFACTION IN THE HUNGARIAN HORTICULTURE

The paper investigates the impacts of trust on the relationships among members and between members and the management in an agricultural marketing cooperative in the Hungarian horticultural sector. We focus on the effects of trust on cooperative members performance and satisfaction and their commitment to remaining a part of cooperative. We analyse the trust along two dimensions: cognitive and affective. Our results suggest that trust among cooperative members and trust between cooperative and management have positive effects on group cohesions. In line with a priori hypotheses we found differences between cognitive and affective trust influencing the group cohesion and cooperative members satisfaction.trust, marketing cooperative, Hungary, Farm Management, Marketing,

Price transmission in the Hungarian vegetable sector

In this paper we analyse price transmission for the carrot, parsley, tomato, green pepper and potato markets. Although there is a dual farm structure dominated by small individual farms, our results imply that price information flows from the producer to the retail level for potatoes, parsley and carrots. Our results also suggest that farmers do not merely accept prices, but can actually influence market prices. Tomato and green pepper prices have large transmission elasticities, and causality runs from the retail to producer level. It therefore follows that tomato and green pepper producers tend to accept prices and that the sector’s prices are determined by upper market levels (processors, wholesalers, retailers). These results are reinforced by the fact that vegetable producers sell a large share of their production through procurement and processing, and therefore are more dependent on the upstream industries, and thus cannot influence prices. For all vegetables in this study the short-run price transmission is symmetric while on the tomato market the long-run price transmission is asymmetric. Results indicate that the tomato market is not competitive and efficient; therefore processors, wholesalers, and retailers are capable of exercising market power, and can instantly transmit producer price increases while just slowly and partially transmitting producer price decreases.Hungarian vegetable sector, producer prices, price transmission, Demand and Price Analysis, Crop Production/Industries,

Dirac eigenmodes at the QCD Anderson transition

Recently we found an Anderson-type localization-delocalization transition in the QCD Dirac spectrum at high temperature. Using spectral statistics we obtained a critical exponent compatible with that of the corresponding Anderson model. Here we study the spatial structure of the eigenmodes both in the localized and the transition region. Based on previous studies in the Anderson model, at the critical point, the eigenmodes are expected to have a scale invariant multifractal structure. We verify the scale invariance of Dirac eigenmodes at the critical point.Comment: to appear in Proceedings of The 32nd International Symposium on Lattice Field Theory, 23-28 June, 2014, Columbia University New York, N