Controlling Agglomeration of Protein Aggregates for Structure Formation in Liquid Oil : A Sticky Business
Vries, Auke De; Lopez Gomez, Yuly ; Jansen, Bas ; Linden, Erik van der; Scholten, Elke - \ 2017
ACS Applied Materials and Interfaces 9 (2017)11. - ISSN 1944-8244 - p. 10136 - 10147.
agglomeration - oleogels - protein aggregates - structure
Proteins are known to be effective building blocks when it comes to structure formation in aqueous environments. Recently, we have shown that submicron colloidal protein particles can also be used to provide structure to liquid oil and form so-called oleogels (de Vries, A. J. Colloid Interface Sci. 2017, 486, 75−83). To prevent particle agglomeration, a solvent exchange procedure was used to transfer the aggregates from water to the oil phase. The aim of the current paper was to elucidate on the enhanced stability against agglomeration of heat-set whey protein isolate (WPI) aggregates to develop an alternative for the solvent exchange procedure. Protein aggregates were transferred from water to several solvents differing in polarity to investigate the effect on agglomeration and changes in protein composition. We show that after drying protein aggregates by evaporation from solvents with a low polarity (e.g., hexane), the protein powder shows good dispersibility in liquid oil compared to powders dried from solvents with a high polarity. This difference in dispersibility could not be related to changes in protein composition or conformation but was instead related to the reduction of attractive capillary forces between the protein aggregates during drying. Following another route, agglomeration was also prevented by applying high freezing rates prior to freeze-drying. The rheological properties of the oleogels prepared with such freeze-dried protein aggregates were shown to be similar to that of oleogels prepared using a solvent exchange procedure. This Research Article provides valuable insights in how to tune the drying process to control protein agglomeration to allow for subsequent structure formation of proteins in liquid oil.
Clustering as an Organizational Response to Capital Market Inefficiency: Evidence from Microenterprises in Ethiopia
Ali, M.A. ; Peerlings, J.H.M. ; Zhang, X. - \ 2014
Small Business Economics 43 (2014)3. - ISSN 0921-898X - p. 697 - 709.
division-of-labor - credit constraints - industry - growth - finance - agglomeration - efficiency - returns - china - industrialization
Absence of a well-developed capital market has been listed as a key obstacle to industrialization in developing countries in the development literature. In this paper, we show that industrial clusters, through specialization and division of labor, can ease the financial constraints of microenterprises even in the absence of a well-functioning capital market. By using data from more than 17,000 microenterprises in four sectors and four regions of Ethiopia, we find that clustering lowers capital entry barrier by reducing the initial investment required to start a business. This effect is found to be significantly larger for microenterprises investing in districts with high capital market inefficiency, indicating the importance of clustering as an organizational response to a credit constrained environment. The findings highlight the importance of cluster-based industrial activities as an alternative method of propagating industrialization when local conditions do not allow easy access to credit.
Farm household’s entry and exit into and from non-farm enterprises in rural Ethiopia: Does clustering play a role?
Ali, M.A. ; Peerlings, J.H.M. - \ 2012
Agricultural Economics 43 (2012)3. - ISSN 0169-5150 - p. 253 - 266.
industrialization - agglomeration - industry - productivity - determinants - competition - africa - growth
This article examines how clustering affects the entry and exit decisions of farm households into and from nonfarm enterprises in rural Ethiopia. We find that the existence of clusters of microenterprises in the same district increases the likelihood of a rural household to start a nonfarm enterprise. Similarly, clustering of big manufacturing firms in the same zone is found to increase the likelihood of farm households to start a nonfarm enterprise. Nonfarm enterprises operating in clusters are also found to have a lower probability of exit than those operating outside of clusters. The study further investigates the impact of entry and exit into and from nonfarm enterprises on farm household's well-being using as indicators total household income, the food security status of a household, and the household's ability to raise enough money in case of emergency. Using propensity score matching to account for selection bias, we find that entry into nonfarm enterprises significantly increases household's income and food security status. Exit from nonfarm enterprises, on the other hand, is found to significantly reduce household's income.
Does 'grey' urban living lead to more 'green' holiday nights? A Netherlands Case Study
Sijtsma, F.J. ; Vries, S. de; Hinsberg, A. van; Diederiks, J. - \ 2012
Landscape and Urban Planning 105 (2012)3. - ISSN 0169-2046 - p. 250 - 257.
decision-support - cities - space - areas - agglomeration - valuation - economics - ecosystem - location - benefits
Urbanisation is seen as essential to wealth creation and increased productivity, but the process has costs as well as benefits. In the present paper we conduct an empirical analysis for the highly urbanised Netherlands on the relation between the greyness of the living environment and the compensating behaviour of more holiday nights spent away from home. We perform a secondary analysis of a survey on holiday behaviour enriched with the outcomes of a GIS model on recreational shortages. We find that the higher the greyness of the living environment – i.e. the higher the shortage of locally available green space for recreational walking – the more people spend nights away from home. Approximately 6% of all Dutch holiday nights may be related to a shortage of green space for recreational walking in the urban living environment. For people living in the most grey urban areas, 20% of their holiday nights appear to be related to a shortage of green space; for people in the least grey areas 10% relates to a shortage of green space. We think that this empirical relation is an important contribution to an assessment of the consequences of agglomeration that goes beyond labour productivity and moves towards well-being
Indirect benefits of infrastructure improvement in the case of an imperfect labor market
Xueqin Zhu, Xueqin ; Ommeren, Jos van; Rietveld, P. - \ 2009
Transportation Research. Part B, Methodological 43 (2009)1. - ISSN 0191-2615 - p. 57 - 72.
unemployment benefits - equilibrium - agglomeration - models - wages
We perform a welfare analysis of transport infrastructure improvements in the presence of an imperfect labor market, allowing for endogenous wages and involuntary unemployment. Efficiency wage setting is incorporated in a spatial two-region general equilibrium model, written as a welfare program. In our model, firms set wages above the market clearing level to create an inducement for employees not to shirk. The economy-wide effect (i.e. social welfare or total welfare) consists of the direct effect in transport market and the indirect effect in other markets. We conduct welfare analyses different from the conventional cost-benefit analysis, in which we distinguish between the direct welfare effect based on consumer surplus in the transport market and the indirect welfare effect through changes in regional unemployment, which is captured in the economy-wide effect. In our model, infrastructure improvement may increase unemployment in one region, but overall unemployment levels fall. The indirect welfare effects through decreases in overall unemployment are about 10-20% of the direct welfare effects for most plausible labor market parameters. The indirect welfare effects are larger, the poorer the initial transport infrastructure and the larger the labor market imperfections