Economics of Hybrid Photovoltaic Power Plants

The global power supply stability is faced to several severe and fundamental threats, in particular steadily increasing power demand, diminishing and degrading fossil and nuclear energy resources, very harmful greenhouse gas emissions, significant energy injustice and a structurally misbalanced ecological footprint. Photovoltaic (PV) power systems are analysed in various aspects focusing on economic and technical considerations of supplemental and substitutional power supply to the constraint conventional power system. To infer the most relevant system approach for PV power plants several solar resources available for PV systems are compared. By combining the different solar resources and respective economics, two major PV systems are identified to be very competitive in almost all regions in the world. The experience curve concept is used as a key technique for the development of scenario assumptions on economic projections for the decade of the 2010s. Main drivers for cost reductions in PV systems are learning and production growth rate, thus several relevant aspects are discussed such as research and development investments, technical PV market potential, different PV technologies and the energetic sustainability of PV. Three major market segments for PV systems are identified: off-grid PV solutions, decentralised small scale on-grid PV systems (several kWp) and large scale PV power plants (tens of MWp). Mainly by application of ‘grid-parity’ and ‘fuel-parity’ concepts per country, local market and conventional power plant basis, the global economic market potential for all major PV system segments is derived. PV power plant hybridization potential of all relevant power technologies and the global power plant structure are analyzed regarding technical, economical and geographical feasibility. Key success criteria for hybrid PV power plants are discussed and comprehensively analysed for all adequate power plant technologies, i.e. oil, gas and coal fired power plants, wind power, solar thermal power (STEG) and hydro power plants. For the 2010s, detailed global demand curves are derived for hybrid PV-Fossil power plants on a per power plant, per country and per fuel type basis. The fundamental technical and economic potentials for hybrid PV-STEG, hybrid PV-Wind and hybrid PV-Hydro power plants are considered. The global resource availability for PV and wind power plants is excellent, thus knowing the competitive or complementary characteristic of hybrid PV-Wind power plants on a local basis is identified as being of utmost relevance. The complementarity of hybrid PV-Wind power plants is confirmed. As a result of that almost no reduction of the global economic PV market potential need to be expected and more complex power system designs on basis of hybrid PV-Wind power plants are feasible. The final target of implementing renewable power technologies into the global power system is a nearly 100% renewable power supply. Besides balancing facilities, storage options are needed, in particular for seasonal power storage. Renewable power methane (RPM) offers respective options. A comprehensive global and local analysis is performed for analysing a hybrid PV-Wind-RPM combined cycle gas turbine power system. Such a power system design might be competitive and could offer solutions for nearly all current energy system constraints including the heating and transportation sector and even the chemical industry. Summing up, hybrid PV power plants become very attractive and PV power systems will very likely evolve together with wind power to the major and final source of energy for mankind.

Study of individual lactation patterns of Iranian dairy buffaloes

The aims of the current study were 1) to investigate the effects of some environmental factors on lactation curve traits (LCTs) including initial milk yield (A), peak yield (PY), days to attain peak yield (PD), inclining- and declining slope of lactation (B and C, respectively), persistency (Per), and 240-d milk yield, and 2) to estimate pairwise phenotypic correlations between these traits in two Iranian buffalo ecotypes (Khuzestani and Azeri buffaloes). The dataset consisted of 15396 and 9283 lactations from 6632 Khuzestani and 3558 Azeri buffaloes, respectively (collected during 1992–2009). The results revealed that almost all of the factors had significant effects on the majority of the LCTs, whereby age group, parity and season of calving had greater influence on 240-d milk yield and PY than the other LCTs in both of the ecotypes. These effects were more apparent in Khuzestani buffaloes than in Azeri buffaloes. In the Khuzestani ecotype, the LCTs were significantly correlated with each other. However, in the Azeri ecotype the 240-d milk yield showed no significant relationship with parameters B, PD and Per. In conclusion, the studied factors play an important role in determining both the shape of the lactation curve and the overal performance of Iranian dairy buffaloes.

Effect of within-litter birth weight variation on piglet survival and pre-weaning weight gain in a commercial herd

There are several factors that affect piglet survival and this has a bearing on sow productivity. Ten variables that influence pre-weaning vitality were analysed using records from the Pig Industry Board, Zimbabwe. These included individual piglet birth weight, piglet origin (nursed in original litter or fostered), sex, relative birth weight expressed as standard deviation units, sow parity, total number of piglets born, year and month of farrowing, within-litter variability and the presence of stillborn or mummified littermates. The main factors that influenced piglet mortality were fostering, parity and within-litter variability especially the weight of the individual piglet relative to the average of the litter (P<0.05). Presence of a mummified or stillborn littermate, which could be a proxy for unfavourable uterine environment or trauma during the birth process, did not influence pre-weaning mortality. Variability within a litter and the deviation of the weight of an individual piglet from the litter mean, influenced survival to weaning. It is, therefore, advisable for breeders to include uniformity within the litter as a selection criterion. The recording of various variables by farmers seems to be a useful management practice to identify piglets at risk so as to establish palliative measures. Further, farmers should know which litters and which piglets within a litter are at risk and require more attention.

Values and their influence on the life satisfaction of adolescents aged 12 to 16: a study of some correlates

In this research we explore several aspects of quality of life in young people, working with factors such as self-esteem, locus of control, perceived social support, values, and so on. We examine the correlations among factors that influence the values and life satisfaction of adolescents aged 12-16. Furthermore, we analyze the data obtained from the children, on the one hand, and their parents, on the other, we explore the relationships between the factors and we consider the agreements and discrepancies between the responses of parents and their offspring

PPP, UIP and Fisher parity: speculation or rational expectations? Evidence for four Latin American countries

This work aims to test the equilibrium relations of two international macroeconomics models for Colombia, Chile, Mexico and Brazil. The first model is the rational expectation hypothesis (REH) where three key relations will be tested: Purchasing Power Parity (PPP), Uncovered Interest Rate Parity (UIP) and the Fisher Parity condition. The second model follows the line of though of Imperfect Knowledge Economics (IKE) where two equilibrium relations will be tested. According to IKE, even under the assumption that agents are rational, the presence of speculative behavior in financial markets helps explain the long swings often observed in the behavior of exchange rates. The results support the view that the predictions of the IKE model hold for Colombia, while those of the REH hold for both Brazil and Mexico. Mixed findings are obtained for Chile.

An approach from positive psychology to mental health of university freshmen in Concepcion (Chile)

University is a demanding and changing environment for first year students, what could affect their mental health and their academic performance. Due these conditions, this research wanted to analyze mental health in freshmen of a private university in, Concepción, Chile, oriented by an approach from positive psychology. 554 were selected and surveyed to evaluate three variables: self-Esteem, satisfaction with life and optimism. furthermore, socio-demographic characteristics and mental health problems were assessed. Outcomes show that students evaluate positively themselves, their life and future. In addition, these variables are related with age, type of former school, religion, depression and anxiety. Systematic relationship found between these three strengths of mental health and their inverse relationship with the most prevalent problems in this area highlight the relevance that these three variables could have to define preventive and remedial strategies to promote student welfare.

Does the unemployment benefit institution affect the productivity of workers? evidence from a field experiment

We investigate whether and how the type of unemployment benefit institution affects productivity. We designed a field experiment to compare workers’ productivity under a welfare system, where the unemployed receive an unconditional monetary transfer, with their productivity under a workfare system, where the transfer is received conditional on the unemployed spending some time on ancillary activities. First, we find that having an unemployment benefit institution, regardless of whether it makes transfers conditional or unconditional, increases workers’ productivity. Second, we find that productivity is higher under Welfare than under Workfare. Becoming unemployed under Welfare comes at the psychological cost of a drop in self-esteem, presumably due to the shame or stigma associated with receiving an unconditional unemployment benefit. We document the empirical relevance of precisely this channel. The differences we observe in productivity suggest that this psychological cost acts as an extra nonmonetary incentive for workers under Welfare to put a higher effort in their work.

La inclusión social y laboral de las personas con discapacidad intelectual mediante los programas de empleo con apoyo : un reto para la Orientación. 'Social and labour inclusion of people with intellectual disability through supported employment programs : a challenge for guidance'.

Resumen tomado de la publicación. Con el apoyo económico del departamento MIDE de la UNED

An evaluation of the CID perceived self-competence questionnaire

This paper discusses self-esteem and hearing impaired children based on the results of a questionnaire administered to students at CID.

On the use of headline indices to link environmental quality and income at the level of the nation state

This paper deconstructs the relationship between the Environmental Sustainability Index (ESI) and national income. The ESI attempts to provide a single figure which encapsulates environmental sustainability' for each country included in the analysis, and this allied with a 'league table' format so as to name and shame bad performers, has resulted in widespread reporting within the popular presses of a number of countries. In essence, the higher the value of the ESI then the more 'environmentally sustainable' a country is deemed to be. A logical progression beyond the use of the ESI to publicise environmental sustainability is its use within a more analytical context. Thus an index designed to simplify in order to have an impact on policy is used to try and understand causes of good and bad performance in environmental sustainability. For example the creators of the ESI claim that ESI is related to GDP/capita (adjusted for Purchasing Power Parity) such that the ESI increases linearly with wealth. While this may in a sense be a comforting picture, do the variables within the ESI allow for alternatives to the story, and if they do then what are the repercussions for those producing such indices for broad consumption amongst the policy makers, mangers, the press, etc.? The latter point is especially important given the appetite for such indices amongst non-specialists, and for all their weaknesses the ESI and other such aggregated indices will not go away. (C) 2007 Elsevier Ltd. All rights reserved.

Study of the lactation curve in dairy cattle on farms in Central Mexico

Accurate knowledge of lactation curves has an important relevance to management and research of dairy production systems. A number of equations have been proposed to describe the lactation curve, the most widely applied being the gamma equation. The objective of this work was to compare and evaluate candidate functions for their predictive ability in describing lactation curves from central Mexican dairy cows reared under 2 contrasting management systems. Five equations were considered: Gaines ( exponential decay), Wood ( gamma equation), Rook ( Michaelis-Menten x exponential), and 2 more mechanistic ones (Dijkstra and Pollott). A database consisting of 701 and 1283 records of cows in small-scale and intensive systems, respectively, was used in the analysis. Before analysis, the database was divided into 6 groups representing first, second, and third and higher parity cows in both systems. In all cases except second and above parity cows in small-scale systems, all models improved on the Gaines equation. The Wood equation explained much of the variation, but its parameters do not have direct biological interpretation. Although the Rook equation fitted the data well, some of the parameter estimates were not significant. The Dijkstra equation consistently gave better predictions, and its parameters were usually statistically significant and lend themselves to physiological interpretation. As such, the differences between systems and parity could be explained due to variations in theoretical initial milk production at parturition, specific rates of secretory cell proliferation and death, and rate of decay, all of which are parameters in the model. The Pollott equation, although containing the most biology, was found to be over-parameterized and resulted in nonsignificant parameter estimates. For central Mexican dairy cows, the Dijkstra equation was the best option to use in describing the lactation curve.

Effect of feeding supplemental fibrolytic enzymes or soluble sugars with malic acid on milk production

Two trials were conducted to evaluate effects of feeding supplemental fibrolytic enzymes or soluble sugars and malic acid on milk production. In trial 1, 257 cows at four sites were fed a basal diet consisting of no more than 60% of forage DM as corn silage and less than 40% as alfalfa hay. Cows were assigned randomly within site, parity, and two stages of lactation to: 1) control; 2) enzyme A; 3) enzyme B; and 4) soluble sugars and malic acid. There was a 14-d pretreatment and an 84-d treatment period. Enzyme solutions were sprayed on either the forage component or the TMR each day while mixing feed. Trial 2 was similar, except 122 cows at one site in the United Kingdom were fed diets containing forage that was 75% corn silage and 25% grass silage, and all cows began the study between 25 to 31 DIM. Mean milk productions for 233 cows that completed trial 1 were 32.9, 32.5, 32.4, and 32.9 kg/d for control, enzyme A, enzyme B, and soluble sugars and malic acid, respectively. Mean milk productions for 116 cows that completed trial 2 were 28.2, 27.9, 28.8, and 28.4 kg/d, respectively. In vitro analyses of the activities of enzyme solutions indicated that all major cellulose and hemicellulose degrading activities were present; however, the pH optima (approximate pH = 4 to 5) were more acidic, and the temperature optimum (approximately 50 C) was greater than normal pH and temperature in the rumen. If fibrolytic activity in the rumen is a major mechanism of action of supplemental fibrolytic enzymes, it appears that considerable activity of these preparations was lost due to conditions in the rumen. In conclusion, feeding supplemental fibrolytic enzymes or malic acid with soluble sugars had no effect on milk production under the conditions used in this study.

Self-esteem and coping in children with developmental coordination disorder

This study investigated self-esteem in children with developmental coordination disorder (DCD). Fifteen children between the ages of 8 and 12 years diagnosed with DCD were compared with a typically developing group comprising 30 children with average and good motor abilities, using measures of perceived competence, social support and self-esteem. The types of coping strategy generated in response to example vignettes were also compared. There was no significant difference between the groups in global self-esteem, but the children with DCD reported lower athletic and scholastic competence than their typically developing peers. No difference was found between the groups in level of perceived social support. The DCD group generated fewer coping strategies overall, but more passive and avoidant strategies than the typically developing children. The implications of the study are discussed with regard to future research directions, such as the investigation of the effects of motor skill intervention on self-esteem and the development of strategies to protect children's self-esteem.

Cognitive behaviour therapy for low self-esteem: A preliminary randomized controlled trial in a primary care setting

Background and Objectives Low self-esteem (LSE) is associated with psychiatric disorder, and is distressing and debilitating in its own right. Hence, it is frequent target for treatment in cognitive behavioural interventions, yet it has rarely been the primary focus for intervention. This paper reports on a preliminary randomized controlled trial of cognitive behaviour therapy (CBT) for LSE using Fennell’s (1997) cognitive conceptualisation and transdiagnostic treatment approach ( [Fennell, 1997] and [Fennell, 1999]). Methods Twenty-two participants were randomly allocated to either immediate treatment (IT) (n = 11) or to a waitlist condition (WL) (n = 11). Treatment consisted of 10 sessions of individual CBT accompanied by workbooks. Participants allocated to the WL condition received the CBT intervention once the waitlist period was completed and all participants were followed up 11 weeks after completing CBT. Results The IT group showed significantly better functioning than the WL group on measures of LSE, overall functioning and depression and had fewer psychiatric diagnoses at the end of treatment. The WL group showed the same pattern of response to CBT as the group who had received CBT immediately. All treatment gains were maintained at follow-up assessment. Limitations The sample size is small and consists mainly of women with a high level of educational attainment and the follow-up period was relatively short. Conclusions These preliminary findings suggest that a focused, brief CBT intervention can be effective in treating LSE and associated symptoms and diagnoses in a clinically representative group of individuals with a range of different and co-morbid disorders.

The role of efficacy and well-being in guiding the use of education and training services by young homeless mothers

This paper builds on previous work applying the concept of well-being to the field of housing. It uses the concepts of self-esteem, efficacy and social identity to explore the situations of a group of young homeless mothers. In particular, it focuses on the impact of well-being factors, among others, in understanding the uptake of education and training services. The paper concludes by arguing that well-being issues are crucial for housing agencies and others who want to engage with young homeless people.