Dilution Of Resources Research Articles

Improvement of the methods for determining ore losses when designing cement raw material deposit mining by surface miner combines

Relevance. The need to optimize production of cement raw materials and reduce the cost of processing raw materials. A surface miner combine allow high selective mining of a deposit, which helps to reduce moisture content of cement raw materials and reduce energy costs in a cement plant. In open-cast mining of cement raw materials deposits with the use of the surface miner combines, the increase in economic efficiency of mining operations can be achieved by determining the rational values of ore losses and dilution. Aim. To determine rational level of cement raw material losses during field development by surface miners. Objects. Cement industry quarries excavated with of the surface miner combines. Methods. Technical and economic analysis of the cement plant Beočin (Serbia), summation and synthesis of materials, sources and data available in the public domain, as well as calculations to determine the amount of loss and dilution of mineral resources at ore–rock contact for mining conditions of the quarry for extracting cement raw materials. Results. The main problems that arise during mining quarries for extracting cement raw materials have been identified. It concerns the determination of the volume of losses and dilution of mineral resources at the ore–rock contact for mining conditions of the quarry for extraction of cement raw materials. The authors present and substantiate conclusions about further effective application of optimal mining technology, with the use of the surface miner combines, which allows reducing the cost of production of minerals and specific operating costs of transporting carbonate rocks compared to the traditional technology of mining works at 50–60%.

Why phylogenetic signal of traits is important in ecosystems: uniformity of a plant trait increases soil fauna, but only in a phylogenetically uniform vegetation

Phylogenetically closely related plant species often share similar trait states (phylogenetic signal), but local assembly may favor dissimilar relatives and thereby decouple the diversity of a trait from the diversity of phylogenetic lineages. Associated fauna might either benefit from plant trait diversity, because it provides them complementary resources, or suffer from it due to dilution of preferred resources. We hence hypothesize that decoupling of trait and phylogenetic diversity weakens the relationship between the plant-trait diversity and the abundance and diversity of associated fauna. Studying permanent meadows, we tested for combined effects of plant phylogenetic diversity and diversity of two functional traits (specific leaf area, leaf dry matter content) on major groups of soil fauna (earthworms, mites, springtails, nematodes). We found that only in phylogenetically uniform plant communities, was uniformity in the functional traits associated with (i) high abundance in springtails, and (ii) high abundance of the sub-group that feeds more directly on plant material (in springtails and mites) or those that are more prone to disturbance (in nematodes), and (iii) high diversity in all three groups tested (springtails, earthworms, nematodes). Our results suggest that soil fauna profits from the resource concentration in local plant communities that are uniform in both functional traits and phylogenetic lineages. Soil fauna would hence benefit from co-occurrence of closely related plants that have conserved the same trait values, rather than of distantly related plants that have converged in traits. This might result in faster decomposition and a positive feedback between trait conservatism and ecosystem functioning.

Birth order, sibling size and educational attainment in twentieth century Spain

ABSTRACT This research presents new evidence on the negative associations of the number of siblings and birth order with years of schooling among female and male Spanish cohorts born in the first six decades of the twentieth century. Special attention is given to unravelling the separate effects of both factors, sib size and birth order. Based on data from the 1991 Spanish Sociodemographic Survey (SDS), findings in Spain support the theoretical framework of the family conditional resource dilution model and indicate that both number of siblings and birth order have been important and relatively independent factors in reducing educational attainment. The association of family size and birth order with educational attainment was contingent to a significant extent on socio-economic status. Whereas the educational consequences of number of siblings are not uniformly distributed by social class, the results for birth order are much more homogeneous. This suggests that parents in high socioeconomic statuses were able to limit the effects of dilution induced by the number of siblings while the dynamics of the dilution of resources associated with the birth order depended, in part, on factors not entirely controllable by families.

The Dilution of Parents’ Nonmaterial Resources in Stepfamilies: The Role of Complex Sibling Configurations in Parental Involvement

Abstract It has been argued that an increase in the number of siblings means that there are fewer parental investments made per child (resource dilution hypothesis). Yet, these studies are mostly based on biological two-parent families in which it can be assumed that parental resources are distributed more or less equally across siblings. This assumption does not hold in the complex family structure of a stepfamily where not all siblings are biologically related and living in the same household. Since more and more children are growing up in stepfamilies, a distinction between sibling types (full/half/step) is needed. In this study, we focus on the dilution of nonmaterial resources (i.e., parental involvement) and use the OKiN dataset to examine paternal (n = 1,077) and maternal (n = 1,369) resources separately. In this way, this study provides the first comprehensive overview of the dilution of parental resources in stepfamilies. While maternal resources are mostly diluted by full siblings, paternal resources are diluted by all sibling types (full, half, and step). We reflect on the implications of these results for the literature on sibship size as well as the literature on social mobility.

Family Resource Dilution in Expanded Families and the Empowerment of Married Only Daughters: Evidence From the Educational Investment in Children in Urban China.

The One-Child Policy dramatically changed the Chinese family structure, and the literature indicates that only children may have an advantage in terms of family resource dilution. Moreover, as Chinese families traditionally prioritize investing in sons, only daughters are found to have been empowered by the policy because they did not need to compete with their brothers for parental investment. However, the literature is limited to only teenage children when they were still living in their parents' homes. It is unclear whether—when the generation of only children grew up and married—their family structure differed from that of children with siblings and whether married only daughters retained more family resources from their parents. Based on the data analysis of a 2016 survey, “Study of Youths in 12 Cities of Mainland China,” including a sample of 1,007 fathers and 2,168 mothers born between 1975 and 1985, this study explores the empowerment of married only daughters, employing the theory of family resource dilution in expanded Chinese families. Using educational investment in children as an example, and with random intercept models, this study presents empirical evidence that the dilution of family resources in Chinese expanded families still benefits males and patrilineal practices. Thus, this study demonstrates that Chinese families still tend to sacrifice the interests of married daughters to ensure support for their adult sons. However, it also illustrates that married only daughters could still connect to their parents' resources, giving them a relatively dominant position for decision-making regarding the family's educational expenditure on her own children. Thus, this study extends our understanding of the family resource dilution theory to Chinese expanded families, underscoring the need for further research on Chinese only children after they marry and form families of their own.

Evaluation of the resource effectiveness of circular economy strategies through multilevel Statistical Entropy Analysis

In a circular economy (CE), materials, components and products should be kept at the highest level of functionality, while phenomena like dilution, mixing and contamination, often referred to as the loss of resources, should be avoided. One method that can assess the performance of systems to concentrate or avoid dilution of resources is Statistical Entropy Analysis (SEA). Up till now, the method has been applied on the substance level (elements and compounds) only, but showed its applicability to various scales and a variety of systems. Further development of the method allowed to consider information on the product, component and material levels, which makes the method applicable to different combinations of CE strategies, both destructive (e.g. recycling) and non-destructive (e.g. reuse). The method is demonstrated on a simplified vehicle life-cycle, which is modeled through four component groups and six materials. It shows that the method allows to evaluate different CE strategies and identify critical stages which lead to the most severe resource and functionality losses. Based on the method's results, it is possible to determine a perfect circularity reference level, representing a system state that preserves functionality and avoids resource losses. The introduction of a circularity reference level enables the establishment of a framework for resource effectiveness in which diluting and concentrating effects of activities (e.g. sorting) are quantified. The distance of a system to an ideal circular state determines the deviation from a resource-effective system that maintains the original product functionality over a maximum period of time, with minimal efforts.

How much would each researcher receive if competitive government research funding were distributed equally among researchers?

Scientists are increasingly dissatisfied with funding systems that rely on peer assessment and, accordingly, have suggested several proposals for reform. One of these proposals is to distribute available funds equally among all qualified researchers, with no interference from peer review. Despite its numerous benefits, such egalitarian sharing faces the objection, among others, that it would lead to an unacceptable dilution of resources. The aim of the present paper is to assess this particular objection. We estimate (for the Netherlands, the U.S. and the U.K.) how much researchers would receive were they to get an equal share of the government budgets that are currently allocated through competitive peer assessment. For the Netherlands, we furthermore estimate what researchers would receive were we to differentiate between researchers working in low-cost, intermediate-cost and high-cost disciplines. Given these estimates, we then determine what researchers could afford in terms of PhD students, Postdocs, travel and equipment. According to our results, researchers could, on average, maintain current PhD student and Postdoc employment levels, and still have at their disposal a moderate (the U.K.) to considerable (the Netherlands, U.S.) budget for travel and equipment. This suggests that the worry that egalitarian sharing leads to unacceptable dilution of resources is unjustified. Indeed, our results strongly suggest that there is room for far more egalitarian distribution of funds than happens in the highly competitive funding schemes so prevalent today.

The quality-quantity trade-off among Australian children

There is a lack of consistent empirical evidence to support an adverse effect on child outcomes with increasing family size, popularly known as the quality-quantity trade-off. The finding of a negative ‘average’ effect of family size indicates that the dilution of parental inputs and resources leads to worsening child quality. We investigate the effect of additional children across the distribution of child outcomes using quantile treatment effects, as parental investment could arguably be heterogeneous. Identification is achieved through two well-known instruments; we obtain upper bounds using multiple birth status of the child, as well as more conservative estimates using a sex composition instrument. We find that the trade-off exists for four different measures of cognitive development and health among Australian children, and affects all children irrespective of their position in the outcome distribution. Our findings are of particular relevance in light of the Australian government’s policy focus on boosting fertility.

Från lokal förankring till regional samverkan? FoU­-miljöer i socialtjänstens individ­ och familjeomsorg

R&D units in Swedish social services: From local integration to regional collaboration For a period of over thirty years, the emergence of R&D units serving locally based Swedish social services has been considered an important ingredient in the evolvement of more professional and knowledge-based social services. It has also been regarded as a vital component for increasing practice orientation in social work research, both inside and outside the universities. In this article we describe and analyse the development of these units, with respect to their proliferation, organizational features and how they are valued by representatives of local social services. Our data show that almost every municipality in Sweden is, in one way or another, served by an R&D unit. These units, however, display a considerable variation with respect to basic resources, activity and organizational framework. Data enabled the identification of four basic categories that, more or less, represent different phases in the evolvement of R&D activities. At one end, representing the early stages, there are units integrated with and exclusively serving single municipalities. At the other end there are R&D units organized within regional associations, serving multiple municipalities and in general established in recent years. In between, there are two categories of R&D units formed in direct collaboration between a limited number of municipalities – one category formally connected to academia, another with less systematic contacts with university-based research. In general, development over time has resulted in a dilution of resources and an increasing distance between practice and R&D activities. Originally, the units were established by the initiatives of the municipalities and expected to respond to research needs emanating from practice. The regional associations have to a considerable extent been initiated and funded by earmarked state grants with the intention to implement evidence-based practice.

Criteria for extending the operation periods of thermoelectric converters based on IV-VI compounds

The recent energy demands affected by the dilution of conventional energy resources and the growing awareness of environmental considerations, had positioned the research of renewable energy conversion methods in general and of thermoelectric direct conversion of thermal into electrical energies in particular, in the forefront of the currently active applicative sciences. IV-VI thermoelectric compounds (e.g. GeTe, PbTe and SnTe) and their alloys comprise some of the most efficient thermoelectric compositions ever reported. Yet a proper utilization of such materials in practical thermoelectric devices, still requires an overcoming the so-called technological “valley of death”, including among others, transport properties' degradation, due to sublimation of volatile Te rich species, while being subjected to elevated temperatures for long periods of time. In an attempt to establish practical operation criteria for extending the operation periods of such thermoelectric converters, it is currently shown based on thermal gravimetric and metallurgical considerations that such harmful sublimation can be practically bridged over by limiting the maximal operating temperatures to the 410–430°C range for GeTe rich alloys and to 510–530°C for PbTe and SnTe rich alloys, depending of the thermoelectric leg's diameter.

Mineral Resource Estimation (M.E. Rossi and C.V. Deutsch)

Mineral Resource Estimation. Mario E. Rossi, Clayton V. Deutsch. 2014. Springer, Dordrecht, Heidelberg, New York, London. Pp. 332. ISBN 978-1-4020-5716-8: Hardcover, $119. ISBN 978-1-4020-5717-5: eBook, $89. Mineral Resource Estimation is about estimating mineral resources at the scale of an ore deposit and is not to be confused with mineral resource assessment , which is undertaken at a significantly broader scale, even if similar data and geospatial/geostatistical methods are used. The book describes geological, statistical, and geostatistical tools and methodologies used in resource estimation and modeling, and presents case studies for illustration. The target audience is the expert, which includes professional mining geologists and engineers, as well as graduate-level and advanced undergraduate students. The authors, Mario E. Rossi and Clayton V. Deutsch, are both graduates of Stanford University. Rossi founded Geo-Systems International in 1994 and provides a wide range of advanced geostatistical and modeling services. Deutsch is director and professor in the School of Mining and Petroleum Engineering, Department of Civil & Environmental Engineering at the University of Alberta. He is also the director and founder of the Centre for Computational Geostatistics (CCG), a research program at the University of Alberta that provides education and training in geostatistics and development and delivery of geostatistical tools. Together, the authors offer a broad range of expertise and experience. The stated aim of their book is to provide a balanced presentation of theoretical and practical aspects of geostatistical methods for resource estimation. Mineral Resource Estimation draws upon classical and modern literature, current best practices, and the rather extensive experience and on-going research efforts of the authors. The subject matter deals mainly with the manifold facets of block models, including issues related to drill hole, trench, and pit sample data collection and preparation, database construction, spatial variability, mining dilution and estimation of recoverable resources, model validations and reconciliations, model limitations and uncertainty, and characterization of risk. Rossi and Deutsch explain that block models describe three-dimensional volumes using relatively small parallelepipeds (solid …

Electronic tuning of the transport properties of off-stoichiometric PbxSn1−xTe thermoelectric alloys by Bi2Te3 doping

The recent energy demands affected by the dilution of conventional energy resources and the growing awareness of environmental considerations had motivated many researchers to seek for novel renewable energy conversion methods. Thermoelectric direct conversion of thermal into electrical energies is such a method, in which common compositions include IV-VI semiconducting compounds (e.g., PbTe and SnTe) and their alloys. For approaching practical thermoelectric devices, the current research is focused on electronic optimization of off-stoichiometric p-type PbxSn1−xTe alloys by tuning of Bi2Te3 doping and/or SnTe alloying levels, while avoiding the less mechanically favorable Na dopant. It was shown that upon such doping/alloying, higher ZTs, compared to those of previously reported undoped Pb0.5Sn0.5Te alloy, were obtained at temperatures lower than 210–340 °C, depending of the exact doping/alloying level. It was demonstrated that upon optimal grading of the carrier concentration, a maximal thermoelectric efficiency enhancement of ∼38%, compared to that of an undoped material, is expected.

Birth Order Effects on Educational Attainment and Educational Transitions in West Germany

Using sibling data from the German Life History Study and fixed-effects models, I find that birth order has a strong negative effect on educational attainment in West Germany—being born later translates to less education. The strength of the birth order effect is comparable to those of many commonly used family background indicators. This finding contrasts many sceptical accounts of birth order found in the sociological and psychological literatures. The results of this study also show the sensitivity of birth order estimates to model specification, pointing to a likely cause for conflicting results in the previous literature. Birth order effects are weaker for females and in larger families, but do not vary according to families' socioeconomic characteristics. The effects are likewise strong at transition from compulsory school to Gymnasium, but not significant on the transition from Gymnasium to university. Overall, the results do not support theories emphasizing the dilution of socioeconomic resources, nor do they support theories on age-crossovers in birth order effects at around age 11. However, the dilution of other family resources such as parental time and attention is a possible candidate. The weaker birth order effects among females can reflect the traditionally gender unequal returns to education, in which intellectual and school performance advantages to lower birth order do not translate into better educational attainment among German women. Overall, these findings underline the importance of birth order in shaping socioeconomic achievement and, more generally, of the factors that affect the experiences and inequalities of children growing up in the same family.

Should physicians routinely be involved in the care of elderly surgical patients? Yes

Standards of care for elderly people in hospital have come under the spotlight. <b>Kathy Wilkinson</b> and <b>Helen Wilson </b>believe that geriatricians can help improve the management of surgical patients, but...

Should physicians be routinely involved in the care of elderly surgical patients? No

Standards of care for elderly people in hospital have come under the spotlight. Kathy Wilkinson and Helen Wilson (doi:10.1136/bmj.d1070) believe that geriatricians can help improve the management of surgical patients,...

Sibship size and status attainment across contexts: Evidence from the Netherlands, 1840-1925

Abstract This paper investigates the effects of sibship size on status attainment across different contexts and subgroups. Resource dilution theory predicts that with larger sibship size, children's status outcomes fall. However, the empirical record has shown that this is not always the case. In this paper we have tested three alternative hypotheses for neutral or even positive effects of sibship size on status attainment on the basis of a large-scale registry database covering the period of industrialization and fertility decline in the Netherlands in the nineteenth and early twentieth-century. Our findings offer support for the family developmental cycle, buffering by kin groups, and socio-economic development as alternative explanations to the resource dilution hypothesis. 1. Introduction What is the role of family structure in society? How, in particular, does the configuration of siblings influence how children's lives turn out? Contemporary research on status attainment in Western societies, whether it is geared to measuring educational achievement, intelligence, or occupational attainment, consistently demonstrates a strong negative impact of the sibship size of the family of origin on accomplishments later in life (Blake 1981, 1989; Conley 2005; Davis 1997; Downey 1995; Kasarda and Billy 1985; Steelman et al. 2002). With an increasing number of siblings, children's status outcomes consistently fall. This record of empirical evidence confirms the resource dilution explanation - the most widely accepted theory used to explain the relationships between the basic parameters of the sibling group and children's outcomes. The resource dilution model dates back to the law of capillary action, framed by Arsene Dumont in 1890 and stating that the presence of siblings attenuates resources necessary for social mobility. Developed in a period of demographic transition, Dumont's idea was that when parents wanted their children to be upwardly mobile, they needed to control their fertility and limit their family size. Hence, they would have to trade quantity for quality (Dumont 1890). The resource dilution hypothesis basically depicts the family as a unit that distributes valuable resources to children and this process has implications for children's status outcomes. The amount of resources that can be allocated to any given child depends both on the amount of resources in the family, and on the number of children. The larger the family is, the greater the dilution of resources and therefore the lower the eventual status of the child (Becker 1991; Downey 2001; Steelman et al. 2002). However, over the past decades, a number of studies have presented contradictory evidence. The negative effect of sibship size on child outcomes has been found to be much weaker, neutral or even positive in some developing societies (Buchmann and Hannum 2001; Desai 1995; Eloundou-Enyegue and Williams 2006; Gomes 1984; Hermalin, Seltzer and Lin 1982; Lu and Treiman 2008; Maralani 2008; Razzaque, Streatfield and Evans 2007; Sudha 1997; Yu and Su 2006). Moreover, historical research (Adams and Kasakoff 1992; Van Bavel 2005; Wall 1996), as well as some older sociological work on social class differences in the relation between family size and status attainment (Bayer 1967; Elder 1962), provides evidence that partly refutes the resource dilution hypothesis. These ambiguous findings suggest that there might be different mechanisms at work in the sibship size-child outcome relationship, depending on social-cultural context or subgroup membership. In the literature on sibship size, different explanations have been put forward, ranging from the developmental cycle of the household (Desai 1995), to buffering by extended kin groups (Shavit and Pierce 1991), social institutions (Blake 1989), public policies (Park 2008), and changes in the relationship over the course of socioeconomic development and demographic transition (Maralani 2008; Van Bavel 2005). …

Rapid Access to Genes of Biotechnologically Useful Enzymes by Partial Genome Sequencing: The Thermoalkaliphile Anaerobranca gottschalkii

Anaerobranca gottschalkii strain LBS3^T is an extremophile living at high temperature (up to 65°C) and in alkaline environments (up to pH 10.5). An assembly of 696 DNA contigs representing about 96% of the 2.26-Mbp genome of A. gottschalkii has been generated with a low-sequence-coverage shotgun-sequencing strategy. The chosen sequencing strategy provided rapid and economical access to genes encoding key enzymes of the mono- and polysaccharide metabolism, without dilution of spare resources for extensive sequencing of genes lacking potential economical value. Five of these amylolytic enzymes of considerable commercial interest for biotechnological applications have been expressed and characterized in more detail after identification of their genes in the partial genome sequence: type I pullulanase, cyclodextrin glycosyltransferase (CGTase), two α-amylases (AmyA and AmyB), and an α-1,4-glucan-branching enzyme.

Effects of Sibship Structure Revisited: Evidence from Intrafamily Resource Transfer in Taiwan

Numerous studies have consistently found negative effects of sibship size on educational outcomes. Three main explanations of these effects have been offered in the literature: (1) the dilution of family resources, (2) a changing intellectual environment in the family for each succeeding sibling, and (3) unobserved selectivity at the family level. In this article, the authors propose a fourth explanation as an extension of the resource-dilution hypothesis: In a traditional or transitional society where resources from all family members are pooled together, families may sacrifice the educational opportunities of older (female) siblings and use their remittance to compensate the family expenses, particularly when there are younger siblings. With analyses of data from the Panel Study of Family Dynamics (PSFD), the authors found empirical evidence to support this explanation. In particular, they found that the negative effects of sibship size are the strongest for girls with younger brothers and sisters who are spaced apart from them. They interpret this unusual high-order interaction involving sibship size, gender, density, and seniority within the context of Taiwan's patriarchal culture, in which families typically favor boys over girls.

Gender and nutritional status at the household level among Gwembe Valley Tonga children, 0-10 years

Gender bias usually favors males, yet among the matrilineal Gwembe Tonga of Zambia, females appear to receive preferential treatment. It is hypothesized that children in polygynous households will have increased levels of malnutrition due to the dilution of resources. Further, if gender bias is observed, it will favor females. The presence of preferential treatment during preadolescence is assessed by measuring physical status in the household. Monogamous or polygynous status of households is considered in this analysis of 188 children of age 0-10 years. The sample, 63 households from two rural villages, includes 47 females and 49 males in monogamous households and 52 females and 40 males in polygynous households. Comparisons of nutritional status are made with < or =-2.0 SD as indicative of stunting (height-for-age), wasting (weight-for-height), and chronic underweight (weight-for-age). Boys have better nutrition in monogamous households-40.8% stunted and 24.5% underweight compared to 62.5% stunted (P = 0.021), 42.5% underweight (P = 0.036) in polygynous households. Female stunting does not differ significantly by household type (40.4% monogamous, 42.3% polygynous). Low levels of wasting in either sex regardless of household type were observed. Girls have better physical status than boys in polygynous households, thereby supporting our combined hypotheses and demonstrating gender bias in pre-adolescents.

Rotifers in different environments of the Upper Paraná River floodplain (Brazil): richness, abundance and the relationship with connectivity

Rotifers were collected in the open water of twenty-eight locations (3 rivers, 12 connected lagoons and 13 isolated lagoons) of the upper Parana River floodplain during the high water (February) and low water (August) period of 2001. Greatest species richness was found in rivers during the high water period. Isolated lagoons had the lowest species richness. Abundance was highest in connected lagoons followed by isolated lagoons and then rivers, but did not show marked spatial or temporal variation. Some species dominated in isolated lagoons during high water and others in connected lagoons during the low water. These results were contrary to our expectations; we expected to observe highest species richness and abundance of rotifers in isolated lagoons during both extremes of the hydrological cycle. Our findings suggest the importance of connectivity among environments to rotifer species richness. The absence of an intense flood during 2001 facilitated development of rotifer populations during the high water period due to lack of dilution and high availability of food resources (phytoplankton).