High Entry Research Articles

The effect of organic matter and thermal maturity on the wettability of supercritical CO2 on organic shales

The geologic sequestration of CO2 is a potential solution for decreasing anthropogenic atmospheric CO2 emissions by trapping it underground. A primary mechanism for storage is structural trapping where low permeability and high capillary entry pressure caprock materials hold back the buoyant CO2 from rising to the surface. The wettability (or contact angle) of reservoir and caprock materials in relation to CO2 and formation brine partly determines the efficiency of structural trapping. Current practice applies the results of individual reservoir-comprising minerals recorded under laboratory conditions, to rocks under in-situ reservoir conditions. However, the wide variety of measured contact angles reported in the literature calls this practice into question. Moreover, organic shales have not been the focus of systematic studies. Here we analyzed the wettability of CO2 on organic shales at various organic matter concentrations and thermal maturities. We found that bulk organic shale remains highly water wet with respect to CO2 despite changes to the maturity or concentration of organics. This finding is in contrast to recent molecular dynamic simulations and our initial expectations from previous pore-scale analyses in which organic matter was shown to be hydrophobic. The results are likely due to the remaining mineralogy of the rock dominating the wetting behavior despite concentrations of organics up to 7.9%. This means that reservoirs and aquifers capped by organic rich caprocks may be suitable locations for CO2 storage and that organic matter at concentrations below percolation threshold may not have a detrimental effect on structural trapping efficiency.

The rise and fall of foreign private investment in the jatropha biofuel value chain in Ghana

The article draws on the multi-level perspective (MLP) and global value chain (GVC) frameworks to analyse the drivers and trajectories of foreign private investment in biofuel production in Ghana. It is based on a narrative of the evolution of a niche for jatropha production in Ghana in the period 1995–2016 including company case studies. The factors analysed relating to MLP are alignment of expectations, network formation, and learning and knowledge sharing, and those relating to GVC are chain structure, governance, ownership, and access to land and capital. High entry barriers for creating a new agriculture-based value chain for global biofuel markets, i.e. high volume requirements, high capital needs, and market risks contributed to the collapse of the jatropha sector in Ghana. A low level of learning and knowledge sharing between jatropha actors in Ghana, alongside weak public R&D support, reduced access to technical and managerial information. Confirming previous GVC research on biofuels, policy and NGOs had a stronger influence on the jatropha value chain than in typical agricultural chains. Moreover, global drivers and the strategies and capabilities of foreign investors can strongly influence the development of a new biofuel value chain in a developing country. The latter points complement previous research on jatropha, which highlights politico- economic factors such as land tenure, regional and local power relations, and the interests of donors and NGOs. The study exemplifies a non- evolutionary niche development that goes beyond the European experiences of industrial niche development on which the MLP framework was first established. The importance of investors and policy at different levels of the value chain illustrate the synergies in combining the MLP and GVC frameworks in research on energy transitions in developing countries.

A Decision-making Perspective of the International Entry Mode Choice

Previous research considers the entry mode decision as a rational and as a single decision. In this study, we draw upon decision making theory to argue that entry mode choice is the product of a boundedly rational, sequential decision making process. In the first stage of the entry mode decision-making process, firms eliminate alternative entry modes which do not possess certain critical attributes while in the second stage, the firms select an acceptable entry mode which is a tradeoff of multiple attributes. We contend that the elimination criteria depend on the type of dominant owners. Therefore, we examine the entry mode decision making process for firms with high levels of family ownership (i.e., family dominant firms) and those with high levels of institutional ownership (i.e., institutionally dominant firms). Specifically, we propose that family dominant firms and institutional dominant firms have different risk profiles that lead to unique entry mode preferences at each stage. That is, higher family ownership leads to the preference for low control, low financial risk entry modes in the first stage. As such, family dominant firms are more likely to eliminate the wholly owned subsidiary in the first stage of the entry mode decision process. Alternatively, institutional investor dominant firms are risk- neutral, so they are more likely to choose high control, high financial risk entry modes. In addition, the tradeoff between control and financial risks is more likely to be considered in the second stage of entry mode decision making process when the counterpart type of owners are involved.

Preparing Preparatory Year English Language Learners for Professional Colleges: An Evaluation of Current Placement System

The present study aims to analyze the pros and cons of both the existing system (English for General Purposes for one year and English for Specific Purposes for six months)and the proposed one (both ESP and EGP for one year) in Preparatory Year Programme (PYP) in Qassim University. It starts with an assumption that if the students are placed on the medical or science track in level-1 instead of level-2, they can be better prepared for the professional colleges after studying ESP for a full year.The study uses quantitative research approach by analyzing the data statistically in a comprehensive way. The complete record of high school grades, Pre-PYP tests and the first semester results of 615 PYP students in the main branch have been thoroughly studied. Likewise, 50 medical male, 50 medical female, 50 science male and 50 science female students have been surveyed on the 5-point Likert scale with 10-items quantitative tool. Major finding is that existing system of placing the students on medical and science tracks in the 2nd semester is better as the students get refined and polished due to the competition and hard work in the 1st semester of PYP. They remain both intrinsically and extrinsically motivated that despite their low performance on the high school exams, aptitude test and entry test, they still have another chance of being placed on the medical track (the first choice of majority of the students). The study, nevertheless, recommends reforms in the existing system without changing it drastically.

Plant Turnover and Structural Reforms in Colombia

In a healthy economy, plant turnover increases aggregate productivity because efficient producers are more likely to survive. Given high entry and exit rates and the potential importance of turnover in accounting for aggregate productivity, in this paper we examine the determinants of plant exits and then examine how exits and other forms of output reallocation contribute to aggregate productivity. Using a unique plant-level longitudinal data set for Colombia for the period 1982-98, we examine the role of productivity and demand as well as input costs in determining plant exits. Moreover, given the important structural reforms introduced in Colombia during the early 1990s, we explore whether and how plant survival changed after these reforms. Our data permit measurement of plant-level quantities and prices, which allows us to decompose productivity and demand shocks and, in turn, to estimate the effects of these fundamentals on plant exit. We find that higher productivity, higher demand, and lower input prices decrease the probability of plant exit. We also find that the importance of physical efficiency and costs in determining exits increases after the introduction of structural reforms. Finally, a decomposition of aggregate productivity suggests that reallocation through entry and exit is important in accounting for the increase in aggregate productivity after the introduction of structural reforms.

Robotic Automation Process - The next major revolution in terms of back office operations improvement

Abstract Forced to provide results consistent results to shareholders the organizations turned to Robotic Process Automation (RPA) in order to tackle the following typical challenges they face: (1) Cost reduction, (2) Quality increase and (3) Faster processes. RPA is now considered the next big thing for the Shared Services Centers (SSC) and Business Process Outsourced (BPO) around the world, and especially in Central and Eastern Europe. In SSCs and BPOs the activities with the highest potential for automation are in finance, supply chain and in human resource departments. This means that the problems these business are facing are mostly related to high data entry volumes, high error rates, significant rework, numerous manual processes, multiple not-integrated legacy systems and high turnover due to repetitive/low value added activities. One advantage of RPA is that it can be trained by the users to undertake structured repeatable, computer based tasks interacting in the same time with multiple systems while performing complex decisions based on algorithms. By doing this, the robot can identify the exceptions for manual processing, remove idle times and keep logs of actions performed. Another advantage is that the automated solutions can work 24/7, it can be implemented fast, work with the existing architecture, cut data entry costs by up to 70% and perform at 30% of the cost of a full time employee, thus providing a quick and tangible return to organizations. For Romania, a key destination for SSCs and BPOs, this technology will make them more competitive, but also will lead to a creation of a series of high-paid jobs while eliminating the low-input jobs. The paper will analyze also the most important vendor providers of RPA solutions on the market and will provide specific case studies from different industries, thus helping future leaders and organizations taking better decisions.

Social mobility and Fair Access to the accountancy profession in the UK

PurposeThe purpose of this paper is to consider how Big Four and mid-tier accountancy firms in the UK are responding to political concerns about social mobility and Fair Access to the accountancy profession.Design/methodology/approachInterviews were undertaken with 18 public accountancy firms, ranked in the Top 30 by fee income, operating in the UK to identify how they are recruiting staff in the light of the Fair Access to the Professions’ agenda. Bourdieusian sociology is used to inform the findings.FindingsThe Big Four firms employ a discourse of hiring “the brightest and the best” to satisfy perceived client demand, where symbolic capital is instantiated by reputational capital, reflecting prestige and specialisation, supported by a workforce with elite credentials. For mid-tier firms, reputational capital is interpreted as the need for individuals to service a diverse client portfolio. In general, most interviewees demonstrated relatively limited awareness of the issues surrounding the Fair Access agenda.Research limitations/implicationsThe interviews with accountancy firms are both exploratory and cross-sectional. Furthermore, the study was undertaken at an embryonic point (2010) in the emerging Fair Access discourse. Future work considering the accountancy profession could usefully examine if, and how, matters have progressed.Social implicationsThe investigation finds that accountancy firms remain relatively socially exclusive, largely due to the requirement for high educational entry standards, and interviewees’ responses generally indicate only limited attempts at engagement with political agendas of promoting Fair Access to the profession.Originality/valueThis paper is the first to empirically evaluate how the accountancy profession is responding to the Fair Access agenda; documents changing patterns of recruitment in accountancy employment, including the hiring of non-graduates to undertake professional work; and augments the literature considering social class and accounting.

Attitudes and opinions of Italian middle-level elites in the new millennium. Adaptation, innovation, or persistence?

The literature on party politics has generally conceived of party change as party adaptation. Building on the theories of institutional change based on critical juncture analysis, our work contributes to the literature in two ways. Theoretically, by unpacking the concept of party change in three dimensions: adaptation, innovation, and persistence. This multidimensionality has been unduly neglected in the literature, too exclusively focussed on party adaptation. Empirically, the article analyses whether the attitudes and opinions of middle-level elites reveal adaptation, innovation, or persistence in their belief system at the beginning of the third millennium. Drawing upon a unique data set of national party delegates of 15 Italian political parties, regression results suggest that high entry barriers in party organizations may hinder Schumpeterian innovation.

Preparing Preparatory Year English Language Learners for Professional Colleges: An Evaluation of Current Placement System

The present study aims to analyze the pros and cons of both the existing system (English for General Purposes for one year and English for Specific Purposes for six months)and the proposed one (both ESP and EGP for one year) in Preparatory Year Programme (PYP) in Qassim University. It starts with an assumption that if the students are placed on the medical or science track in level-1 instead of level-2, they can be better prepared for the professional colleges after studying ESP for a full year.The study uses quantitative research approach by analyzing the data statistically in a comprehensive way. The complete record of high school grades, Pre-PYP tests and the first semester results of 615 PYP students in the main branch have been thoroughly studied. Likewise, 50 medical male, 50 medical female, 50 science male and 50 science female students have been surveyed on the 5-point Likert scale with 10-items quantitative tool. Major finding is that existing system of placing the students on medical and science tracks in the 2nd semester is better as the students get refined and polished due to the competition and hard work in the 1st semester of PYP. They remain both intrinsically and extrinsically motivated that despite their low performance on the high school exams, aptitude test and entry test, they still have another chance of being placed on the medical track (the first choice of majority of the students). The study, nevertheless, recommends reforms in the existing system without changing it drastically.

Identifying strategic groups: an assessment in mexican franchises

The formation of strategic groups in the franchising sector has been previously documented in the context of different countries. Our proposal is the franchise industry in Mexico should be formed by groups of differentiated franchisors. The identification and analysis of the different strategic groups formed in the franchise system of the Mexican market is the objective of this research. Our evaluation was performed using the factor analysis technique in a sample of 167 franchises of national origin. Seven strategic dimensions supported by the theory of scarce resources and agency theory make up the existence of differentiated groups of franchisors in the Mexican market. Our research confirmed the identification of five strategic groups called: rapid growth, converters, experienced and international franchisors, high entry fees and expensive conservatives, which use differentiated strategies to compete in the Mexican market.

PVDF hollow fibers with novel sandwich structure and superior wetting resistance for vacuum membrane distillation

PVDF hollow fiber membranes with a unique sandwich structure and superior wetting resistance have been designed for vacuum membrane distillation (VMD) of seawater desalination in this study. The sandwich structure consists of two sponge-like inner and outer porous layers and a thin middle layer full of small-size macrovoids. The sponge-like structure in the two porous layers is specially designed because it enhances the mechanical strength of hollow fibers with high wetting resistance. This structure is derived from the spinodal liquid-liquid decomposition during phase inversion. Meanwhile, the middle layer of macrovoids is beneficial for VMD flux because they perform as highways for water transport. Comparing to the large size macrovoids, the small-size macrovoids in PVDF hollow fibers are preferred for VMD applications because they would not significantly reduce the membrane mechanical strength. As a result, the newly developed membranes possess impressively high liquid entry pressures (LEPs) of >3bar. This study may provide valuable guidelines in designing next generation PVDF hollow fiber membranes for practical VMD applications.

Dynamics in Input Sourcing

This explores the dynamics of intermediate input sourcing using the confidential U.S. customs trade data from the U.S. Census. I document three key empirical facts on sourcing dynamics, and explain them using a model on supplier uncertainty and learning. I find first that new suppliers have high entry and exit rates, and second, they are given lower shares on average than incumbent suppliers. Third, over time, suppliers' shares tend to converge to an equal level. To explain these facts, I test the two key empirical implications from the Rauch and Watson model. First, supplier uncertainty leads to small orders to new suppliers, and second higher search cost leads to longer relationships. I find evidence consistent with the model and hypothesis of learning.

Unequal school enrollment rights, rent yields gap, and increased inequality: The case of Shanghai

This paper first builds a simple theoretic model to explore how a special feature of enrollment policy of public primary schools in urban China, the unequal enrollment right between home owners and tenants, would produce rent-yields gap between different housings. The model also predicts that an enrollment policy featuring with tenant discrimination, accompanying with strict credit constraint, would reduce the chance of kids from middle-income families to attend better public schools while allow families with high initial wealth to access better high-quality public education at a lower cost. Using a hedonic pricing model, we find that, in Shanghai, rental yields of housings in neighborhoods associated with reputed public primary schools is on average 0.1–0.35 percentage-point lower than those associated with ordinary ones. We also explore how the rent-yields-gap varies across housing types, locations and changes over time. Nonetheless, our simulation computation suggests that the estimated opportunity cost of holding such schools in Shanghai is generally not a big amount and affordable for many families. Overall, the high entry costs of owing a housing is the major obstacle to access high-quality public primary education in urban China. These findings highlight how an education policy with features of inequality may contribute to education and residential segregation, and then reduce intergenerational mobility.

Efficient bootstrap estimates for tail statistics

Abstract. Bootstrap resamples can be used to investigate the tail of empirical distributions as well as return value estimates from the extremal behaviour of the sample. Specifically, the confidence intervals on return value estimates or bounds on in-sample tail statistics can be obtained using bootstrap techniques. However, non-parametric bootstrapping from the entire sample is expensive. It is shown here that it suffices to bootstrap from a small subset consisting of the highest entries in the sequence to make estimates that are essentially identical to bootstraps from the entire sample. Similarly, bootstrap estimates of confidence intervals of threshold return estimates are found to be well approximated by using a subset consisting of the highest entries. This has practical consequences in fields such as meteorology, oceanography and hydrology where return values are calculated from very large gridded model integrations spanning decades at high temporal resolution or from large ensembles of independent and identically distributed model fields. In such cases the computational savings are substantial.

Diagenetic evolution of deep sandstones and multiple-stage oil entrapment: A case study from the Lower Jurassic Sangonghe Formation in the Fukang Sag, central Junggar Basin (NW China)

The deposition and preservation of high-quality rocks in a heterogeneous petroleum reservoir and associated mechanisms for hydrocarbon emplacement and migration are one of the most critical issues in deep exploration. Applying an integrated approach of petrography, SEM, stable carbon and oxygen isotopes, and fluid inclusion analyses, this study was designed to examine the relationship between diagenetic evolution and oil emplacement in the Lower Jurassic Sangonghe Formation in the Fukang Sag, central Junggar Basin (NW China). The sandstones consist mainly of feldspathic litharenite, and litharenite. Primary sandstone texture and compositions (grain size, ductile lithic sand grains) determine reservoir diagenetic heterogeneity. Grain size controls the overall abundances of cement and porosity, and reservoir properties through its effect on ductile lithic grains and hence on mechanical compaction. Ductile lithic-rich, very fine- to fine-grained sandstones had a limited diagenetic process in which compaction of easily deformed, clay-rich lithic grains predominated, resulting in a very rapid loss of porosity during burial. They achieved a high capillary entry pressure before the first oil arrival and were not charged later. In contrast, diagenetic events in the relatively coarser-grained sandstones with less abundant ductile lithic grains included dissolution and cementation as well as ductile compaction. Diagenesis progressed alternately with oil emplacement and in some cases, they occurred synchronously. Late diagenetic Fe-calcite, ankerite, and barite may be good mineralogical signatures of oil charge and migration. The nonreservoir, ductile lithic-rich, tightly compacted sandstones can constitute impermeable barrier interbeds embedded in permeable reservoir rocks, probably resulting in heterogeneous flow.

A Review of the Turbine Cooling Fraction for Very High Turbine Entry Temperature Helium Gas Turbine Cycles for Generation IV Reactor Power Plants

The potential for high turbine entry temperature (TETs) turbines for nuclear power plants (NPPs) requires improved materials and sophisticated cooling. Cooling is critical for maintaining mechanical integrity of the turbine for temperatures >1000 °C. Increasing TET is one of the solutions for improving efficiency after cycle optimum pressure ratios have been achieved but cooling as a percentage of mass flow will have to increase, resulting in cycle efficiency penalties. To limit this effect, it is necessary to know the maximum allowable blade metal temperature to ensure that the minimum cooling fraction is used. The main objective of this study is to analyze the thermal efficiencies of four cycles in the 300–700 MW class for generation IV NPPs, using two different turbines with optimum cooling for TETs between 950 and 1200 °C. The cycles analyzed are simple cycle (SC), simple cycle recuperated (SCR), intercooled cycle (IC), and intercooled cycle recuperated (ICR). Although results showed that deterioration of cycle performance is lower when using improved turbine material, the justification to use optimum cooling improves the cycle significantly when a recuperator is used. Furthermore, optimized cooling flow and the introduction of an intercooler improve cycle efficiency by >3%, which is >1% more than previous studies. Finally, the study highlights the potential of cycle performance beyond 1200 °C for IC. This is based on the IC showing the least performance deterioration. The analyses intend to aid development of cycles for deployment in gas-cooled fast reactors (GFRs) and very high-temperature reactors (VHTRs).

Prior host-country work experience and immigrant labor market outcomes: evidence from Canada

Recent changes to immigration selection policies favor skilled workers with prior work experience in the immigrant host country. Using unique administrative tax data for Canada, we estimate earnings equations to quantify the difference in earnings of immigrants with prior Canadian experience (prefilers) and those without prior experience (non-prefilers). We find that, relative to non-prefilers, entry earnings are higher for prefilers and, for male immigrants, this earnings advantage persists for at least 20 years after arrival. We show that the primary source of the higher entry earnings of prefilers is a higher return to foreign experience. In addition, the prefiler earnings advantage is largest for university graduates and the return to foreign experience is higher for prefilers from Western countries than those from the rest of the world. Our findings suggest that a move towards an immigrant selection system which uses previous host-country work experience as a criterion will improve the labor market performance of immigrants.

Application of Film Cooling to an Unshrouded High-Pressure Turbine Casing

In this paper, we describe the design, modeling, and experimental testing of a film cooling scheme employed on an unshrouded high-pressure (HP) rotor casing. The casing region has high thermal loads at both low and high frequency, with the flow being dominated by the potential field of the rotor and over-tip leakage flows. Increasingly high turbine entry temperatures necessitate internal and film cooling of the casing to ensure satisfactory service life and performance. There are, however, very few published studies presenting computational fluid dynamics (CFD) and experimental data for cooled rotor casings. Experimental testing was performed on a film-cooled rotor casing in the Oxford Turbine Research Facility (OTRF)—a rotating transonic facility of engine scale. Unsteady CFD of an HP rotor blade row with a film-cooled casing was undertaken, uniquely with a domain utilizing a sliding interface in the tip gap. A high density array of thin film heat flux gauges (TFHFGs) was used to obtain time-resolved and time-mean results of adiabatic wall temperature and film cooling effectiveness on the film-cooled rotor casing between −30% and +125% rotor tip axial chord. Results are compared to CFD predictions, and mechanisms for interaction of the coolant with the rotor tip are proposed and discussed. Acoustic effects within casing coolant holes due to the passing of the rotor are demonstrated on a 3D CFD geometry, supporting conclusions drawn in earlier work by the authors on the importance of this effect in a casing film cooling system.

Reactive transport modelling of a high-pH infiltration test in concrete

A laboratory-scale tracer test was carried out to characterize the transport properties of concrete from the Radioactive Waste Disposal Facility at El Cabril (Spain). A hyperalkaline solution (K-Ca-OH, pH = 13.2) was injected into a concrete sample under a high entry pressure in order to perform the experiment within a reasonable time span, obtaining a decrease of permeability by a factor of 1000. The concentrations of the tracers, major elements (Ca2+, SO42−, K+ and Na+) and pH were measured at the outlet of the concrete sample. A reactive transport model was built based on a double porosity conceptual model, which considers diffusion between a mobile zone, where water can flow, and an immobile zone without any advective transport. The numerical model assumed that all reactions took place in the immobile zone. The cement paste consists of C-S-H gel, portlandite, ettringite, calcite and gypsum, together with residual alite and belite. Two different models were compared, one with portlandite in equilibrium (high initial surface area) and another one with portlandite reaction controlled by kinetics (low initial surface area). Overall the results show dissolution of alite, belite, gypsum, quartz, C-S-H gel and ettringite and precipitation of portlandite and calcite. Permeability could have decreased due to mineral precipitation.

Policy analysis on the education of the difficult-to-live group in Osaka ―Focusing on various issues concerning high school entry mainly―

Policy analysis on the education of the difficult-to-live group in Osaka ―Focusing on various issues concerning high school entry mainly―