Initial Stock Research Articles

Report from Brussels: overview of pending and completed legislative initiatives in the area of financial services in the EU – content and state of play

Abstract At the end of the EU’s 2019 – 2024 legislative cycle and just before the next Commission will enter office, this report aims to take stock of the main legislative initiatives at EU level in the area of financial services, in particular in the field of banking and capital markets law. It aims to provide an overview on the procedural state of play as well as the content, following in its approach the earlier report from 2022 (ZBB 2022, 312 ff.).

Effects of European eel egg and larval stocking density on rearing water, offspring bacteriome and derived immune response

If human exploitation of the “critically endangered” European eel (Anguilla anguilla) is to continue, the eel's life cycle in captivity must be closed and techniques established to produce viable offspring in hatcheries. Despite stable offspring production, high mortality rates during early developmental stages have hindered progress in closing the lifecycle in captivity. We hypothesised that mortalities affecting embryos and newly hatched larvae, when the immune system is expected to play a vital role in protecting the offspring, could be linked to adverse microbial conditions arising in high-density rearing. We therefore set out to explore the bacteriome changes in rearing water and offspring as well as the molecular immunologic development of offspring at different initial stocking densities (500, 1000, 2000, and 4000 eggs/L) from fertilisation to 3 days post-hatch (dph). The lowest density resulted in ∼5% higher survival. Independent of density, most mortality (∼75%) occurred during embryonic rather than larval development. The bacteriomes of both offspring and rearing water differed according to stocking density, with a potentially healthier bacteriome at the lowest density, marked by greater ASV richness and abundance from various phyla (Proteobacteria, Actinobacteria, Fusobacteria, and Firmicutes). In contrast, the bacteriome of the highest density was dominated by Proteobacteria ASVs, including the potentially harmful Vibrionales order. We observed stage-specific bacteriome changes in offspring, transitioning from an inherent and balanced bacteriome in unadulterated eggs to a dominance of rapid-growing opportunistic bacteria in embryos (48 hpf), and finally to a more diverse bacterial community in larvae (3 dph). Thus, host-microbe interactions appear to significantly impact the overall high mortality observed during embryonic development. As the expression of stress and immune related genes was not affected by density, it seems that the molecular immune system was incapable of handling microbial interference during these early stages, aggravating the challenges faced during hatchery production. We conclude that low-density (500 eggs/L) incubation is a valid strategy to improve survival. However, high stocking densities (up to 4000 eggs/L) might be an acceptable compromise allowing more efficient utilisation of infrastructure and labour. At 4000 eggs/L, survival was reduced by only ∼5%, while there was no effect on hatching success and no cellular stress response. Nevertheless, bacterial community management tools should be in place during high-density incubation to avoid r-selection and thus counter bacteria-associated mortality.

Survival Rate and Growth Performance of Holothuria scabra Towards Different Stocking Densities and Feeding with Spirulina

Holothuria scabra is widely used in traditional medicine or consumed as a healthy or exotic food, causing wild stocks to decrease. Therefore, aquaculture is the best solution to address this issue and support the growing market demand. However, up to now, H. scabra production is facing problems related to the nursery phase, survival rate of larvae and juveniles, production cost, and broodstock for mass production. In this study, the juveniles of H. scabra were divided into three different stocking densities and fed with 1 g of dissolved Spirulina powder once on alternate days. Their length was recorded every two weeks. After six weeks, the juveniles reared with 100 individual densities showed the highest survival rate at 80% compared to 200 and 400 stocking densities. Meanwhile, every tank showed a positive growth rate, indicating that Spirulina powder could potentially promote the growth of juvenile H. scabra. The specific growth rate for stocking density at 100, 200, and 400 were 1.2, 0.86, and 1.37%/day, respectively. In conclusion, the optimum initial stocking density is between 100 and 200 individuals for a 1-ton fibreglass tank with a 500 L water capacity. The Spirulina can be used as the main protein source as compared to other diets for juvenile H. scabra.

The use of corporate social responsibility in response to product‐harm crisis: How do stock market reactions matter?

AbstractThe initial stock market reaction to a product‐harm crisis is an important factor motivating firms to engage in corporate social responsibility (CSR). By analyzing event data on product‐harm crises in Chinese listed companies spanning from 2009 to 2019, we uncover evidence that crisis‐related abnormal returns have a significant negative association with the subsequent growth of CSR. Importantly, we find that this negative relationship is especially pronounced for firms that have a greater need to restore moral legitimacy, such as those receiving high levels of media favorability and positive analyst recommendations. These findings offer novel insights into the motivations behind firms' increased investment in CSR following product‐harm crises from a legitimacy perspective.

Performance, Carcass Composition, and Meat Quality during Frozen Storage in Male Layer-Type Chickens

An experiment was carried out in the Institute of Animal Science—Kostinbrod, Bulgaria, to investigate the growth performance of male layer-type chickens (Lohmann Brown Classic), raised to 6 and 9 weeks of age, to evaluate the economic aspects of this rearing, as well as to present changes in the quality characteristics of the meat during frozen storage. The chickens were reared in a controlled microclimate with an initial stocking density of 9 birds/m2. After 6 weeks of age, fragmentation of the stocking density was applied, and then it diminished to 3 birds/m2. The chickens were slaughtered at 6 and 9 weeks of age. Ten 9-week-old chickens were subjected to carcass analysis. Meat quality parameters (pH, color), degree of proteolysis (free amino groups), and lipid oxidation (content of peroxides and TBARS) were assessed in fresh breast and thigh meat (0 d) and in samples stored for 60 and 120 days at −18 °C in chickens slaughtered at 6 and 9 weeks old. The mean live weight of the male layer-type chickens at 6 weeks was 608.81 g, while the 9-week-old chickens reached 1115.93 g. The feed conversion ratio (FCR) for the whole period of rearing was 2.75. There were no considerable deviations in the meat traits, indicating quality deterioration over the course of the frozen storage. There was a significant increase in the pH of the breast and thighs, reaching maximum values for 60 days of storage in the 6-week-old chicks, while in the 9-week-old birds, pH peaked in the samples stored for 120 days. The changes in the dynamics of pH corresponded to those of proteolysis. There was an increase in lightness (L*), allowing for higher values in the samples stored for 60 days to be reached regardless of the type of meat and age of the chickens. The content of the peroxides increased considerably for 60 days of frozen storage and decreased afterwards. During storage, there was a constant increase in the secondary products of lipid oxidation. Our results indicated that the application of practices such as the fragmentation of stocking density and finding the suitable age for slaughter have significant importance for the profitability of producing meat product from male layer-type chickens. We found that rearing this type of bird until 9 weeks of age resulted in lower costs and higher economic efficiency.

Long-term organic fertilization combined with deep ploughing enhances carbon sequestration in a rainfed sorghum-maize rotation system

Organic fertilization and deep ploughing are expected to contribute to carbon (C) sequestration in arable soils. This hypothesis was evaluated over 11 years of chemical and organic fertilization under conventional tillage (20 cm) and deep ploughing (40 cm) in a rainfed sorghum-maize rotation system on the Loess Plateau. Soil was collected and analysed to determine the soil organic C (SOC) and total nitrogen (TN) contents in the soil profiles (0–60 cm) or in the macroaggregates, microaggregates and silt and clay fractions (0–20 cm only). The SOC and TN stocks at the 0–60 cm depth displayed a net decrease in the unfertilized control, a marginal increase with chemical fertilizer, a significant increase of 23–45 % and 19–42 %, respectively, with organic amendments and a significant increase of 54 % and 48 %, respectively, when combined with deep ploughing. A critical input amount of 2064 kg C ha−1 yr−1 or 162 kg N ha−1 yr−1 was found to be required to maintain the initial SOC or TN stock. The annual N input was positively correlated with the C sequestration efficiency (P < 0.001). This supports the microbial N mining theory. Organic fertilization increased soil aggregation and the specific activity of N-acetyl-glucosaminidase, which was positively correlated with the specific respiration rate in the whole soil profile (P < 0.001) and aggregates (P < 0.001). This appears to support the stoichiometric decomposition theory. However, deep ploughing decreased the specific activity of N-acetyl-glucosaminidase at the 40–60 cm depth compared with conventional tillage. Collectively, long-term organic fertilization combined with deep ploughing enhances SOC sequestration in three ways: directly through the input of exogenous C, indirectly by alleviating microbial N limitations and increasing the amount and stability of subsoil-associated C, and to a lesser extent by improving soil aggregation.

Factors driving carbon accumulation in forest biomass and soil organic carbon across natural forests and planted forests in China

IntroductionForests play a pivotal role within the global carbon cycle. However, how to enhance carbon storage in existing forests remains unclear.MethodsIn this study, we conduct a comprehensive analysis of data from 2,948 forest sites across China. Utilizing structural equation modeling (SEM), we investigate the intricate relationship between climate, tree species diversity, stand structure, function traits, initial biomass carbon stocks (BCi), soil organic carbon stocks (Soil C content), and carbon accumulation in biomass (ΔBC) and soil organic carbon stocks (ΔSOC) within both natural forests (NF, n = 1,910) and planted forests (PF, n = 1,038).ResultsOur findings underscore the critical influence of tree species diversity and stand structure drivers of both direct and indirect carbon accumulation, with distinct drivers emerging based on the carbon pools in NF and PF. Specifically, increasing tree species diversity from its minimum to maximum value through management-results in a 14.798 tC/ha reduction in BC and 0.686 tC/ha in SOC in NF. Conversely, amplifies BC and SOC in PF by 0.338 tC/ha and 0.065 tC/ha, respectively. Enhancing stand structure-such as stand density-results in a 231.727 tC/ha reduction in BC and SOC in NF, and a 10.668 tC/ha in BC and 64.008 tC/ha increment in SOC in PF.DiscussionOverall, our results indicate that higher tree species diversity, stand density and age-group limits further carbon accumulation in BC and SOC in current NF. In contrast, low tree species diversity and stand density limits the development of carbon storage potential in planted forests. To enhance carbon sequestration capacity, China should change its current policy of completely banning logging of natural forests. Natural forests need thinning and reduced tree species diversity, while planted forests should increase tree species diversity and stand density.

AI for peace: mitigating the risks and enhancing opportunities

Abstract This article focuses on measuring the impact of artificial intelligence (AI) on the peace and security agenda, taking stock of recent initiatives and progress in this area. While there is a keen awareness of the fact that AI can be weaponized to become a tool of power politics and military competition, there is comparatively less systematic attention paid to what technology can do for peace. While it is important to address risk mitigation, equal space should be given to thinking about how to harness the peace potential of AI on a large scale. This study follows a series of publications that aim to assess the impact of technological innovation on peace, also referred to as PeaceTech, Global PeaceTech, peace innovation, or digital peacebuilding. The first section provides an overview of the debate on the impact of AI on peace and conflict. The second section examines conceptual frameworks and measures of the impact of AI on peace and conflict. The third section looks at the risks to peace and conflict posed by the use of AI and possible governance measures to mitigate them. The fourth section provides examples of AI-enabled initiatives that are having a positive impact on peace, providing a compass for public and private investment. The conclusion offers policy recommendations to advance the AI for peace agenda.

The JOBS Act and IPO underpricing

In the realm of Initial Public Offerings (IPOs), the initial day stock price return, known as underpricing, poses a considerable financial burden on capital issuers. This study scrutinizes two hypotheses regarding IPO underpricing: the general information asymmetry theory, positing that ‘underpricing’ compensates for investor uncertainty about firm quality, and the practical underwriter-institutional investor collusion, potentially explaining the recent upswing in underpricing.Our findings indicate that the JOBS Act contributes to an increase in overall IPO underpricing post its 2012 enactment, aligning with the traditional adverse selection phenomenon. Notably, empirical analysis reveals a corresponding upsurge in underpricing tied to the increasing proportional shares of institutional investors in the post-Act period, supporting the collusion hypothesis. In summary, this paper underscores a notable side effect of the JOBS Act, revealing a pronounced increase in underpricing for issuers and subsequently enhancing the attractiveness of the underwriting business.

IPO underpricing and overpricing and long-term firm performance in the Netherlands, United Kingdom, France, Sweden, and Italy: learning from three Dutch IPOs

Aim: This research contributes to the study of the relationship between initial public offering (IPO) under- and overpricing and long-term firm performance as measured by net income. Research methods: Using ordinary least-squares regressions, an international sample of 444 IPOs from the United Kingdom, Sweden, France, Italy, and the Netherlands for the period 2013–2017 is analysed. The data was extracted from the Eikon Refinitiv database. Further, an in-depth analysis of three Dutch IPOs by six interviews with five (former) management members and one investment banker is conducted. Conclusions: The results show that the more profitable a firm is in the long run, the likelier positive initial stock returns move towards zero after the first trading day. The case studies support these findings and the concept of asymmetric information between market participants can offer a partial explanation. Additionally, as firms operating in the industrial and healthcare sector grow larger, the offer price tends to be closer to the overall market demand. Nonetheless, no significant relationship is found between initial stock return and net profitability for other industries. While the country analysis also displays no significant relationship, underpricing is more prevalent in the United Kingdom than in the other sample countries. Originality: This article combines a full-fledged quantitative study with a full-fledged qualitative study on one of the most perilous corporate finance milestones, that is, the complex transformation from a private to a public company through a stock market listing. Limitations: The sample composition skews towards underpriced IPOs. Also, although the notion of reverse causality is discussed based on the views of interviewees, no quantitative evidence is provided.

Aloe barbadensis Effect on Growth Performance and Gastrointestinal Tract of Labeo rohita

Fish is a rich source of nutrients and help to reduce the inadequacy of calcium, vitamin A, iron, protein and cure many diseases. Labeo rohita (Rohu) is commercial species of Pakistan and main food item. The base of this study is to enhance the growth of Labeo rohita under special dietary condition. The aim of this research project was to check the effect of traditional herb Aloe barbadensis on Growth rate, FCR, Survival rate and Gastrointestinal villi histopathology of Labeo rohita fed on different Aloe barbadensis concentration containing diet.&#x0D; Methodology: Initial stocks of 120 Labeo rohita fingerlings having average weight 14.30 +3.51g were bought from Government Fish Hatchery, Faisalabad. Aloe barbadensis leaf’s powder were prepared ad mixed with different concentration of conventional feed ingredients like such as fish meal, rice polish, corn, wheat bran. Four treatments were designed including a control and Aloe barbadensis incorporated in the fish feed at 0%, 05% and 10%, 15% which were administrated for a period of 180 days. This feeding trial remains continued till 180 days in aquarium. Iso nitrogenous diets having protein level 33±1g.45 but different concentration of Aloe barbadensis were prepared and fed to fingerlings. Ingredients quantity was calculated by using Pearson square method. Conventional feed ingredients i.e. fish meal, rice polish, corn and wheat brane were used in feed in pellet forn. At the end of feeding trial three fish from each aquarium were selected randomly for gastrointestinal analysis. Gastrointestinal Villi parameters like length, width of intestine villi were measured at the end of trail.&#x0D; Results: According to results, different levels of Aloe barbadensis leave’s powder had significant positive effect upon Growth, Survival rate, and FCR. Results showed that Aloe barbadensis at 15% (T3) resulted in improved growth rate, Survival rate and feed conversion ratio (FCR). The Aloe barbadensis-treated groups showed improvement in intestinal villi length, width and gap between villi. The present study suggests that Aloe barbadensis especially at 15% feed administration may enhance effectively the growth performance and gastrointestinal (villi) parameters like length, width and gap between villi of Labeo rohita.

Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of Eucalyptus urophylla × E. grandis

Stump–root systems consist of aboveground stumps and underground coarse roots after timber harvesting. Stump–root systems are the primary source of coarse woody debris (CWD) in plantations, and they play a crucial role in the material cycle, energy flow, and biodiversity of Eucalyptus plantation ecosystems. However, there is limited knowledge about the changes in elemental stock within this CWD type during decomposition. To address this gap, we conducted a study on Eucalyptus urophylla × E. grandis stump–root systems at various times (0, 1, 2, 3, 4, 5, and 6 years) after clearcutting. Our aim was to investigate the stock changes in eight elements (K, Ca, Mg, S, Fe, Mn, Cu, and Zn) within the stumps and coarse roots over time and their decay levels, and we analyzed the relationship between elemental stocks and the physical, chemical, and structural components of stump–root systems. Our findings revealed the following: (1) The majority of each element’s stock within the stump–root system was found in the coarse roots. The elemental stocks in both stumps and coarse roots decreased as time passed after clearcutting and as decay progressed. (2) Notably, the elemental stocks in stumps and coarse roots were significantly higher than in other treatments during the initial 0–2 years after clearcutting and at decay classes I and II. In terms of elemental stocks, stumps from all clearcutting times or decay classes had the highest K stock, followed by Ca and Fe. Mg, Mn, and S stocks were lower than the first three, while Zn and Cu stocks were very low. The ordering of elemental stocks from high to low in the stump–root systems generally aligned with that of the coarse roots. (3) The residual rates of K, Mg, and Mn stocks in the stump–root systems fit the negative exponential model well. It took approximately 1 to 3.5 years for a 50% loss of the initial stocks of these elements and 5 to 10 years for a 95% loss. (4) The large amount of biomass in the stump–root system is the long-term nutrient reservoir of plantations, and any factor related to biomass loss affects the magnitude and duration of the nutrient reservoir, such as N, P, stoichiometric ratios, density, water-holding capacity, and hemicellulose. These findings contribute to a better understanding of the nutrient elemental dynamics and ecological functions of stump–root systems in Eucalyptus plantations.

PRICING OF CALL OPTIONS USING THE QUASI MONTE CARLO METHOD

A call option is a type of option that grants the option holder the right to buy an asset at a specified price within a specified period of time. Determining the option price period of time within a certain period of time is the most important part of determining an investment strategy. Various methods can be employed to determine the prices of options, such as Quasi-Monte Carlo and Monte Carlo simulations. The purpose of this research is to determine the price of European-type call options using the Quasi-Monte Carlo method. The data used is daily stock closing price data on the Apple Inc. for the period October 1, 2021, to September 30, 2022. Apple Inc. stock options in this study were chosen because it is the largest technology company in the world in 2022. The steps taken in this study are to determine the parameters obtained from historical data such as the initial risk-free interest rate (r), stock price (, volatility , maturity time (T), and strike price (K). Next is to generate Halton’s quasi-randomized sequence and simulate the stock price by substituting the parameters by substituting the parameters. Then proceed to calculate the call option payoff and estimate the call option price by averaging the call option payoff values. The results showed that the call option price of the company Apple Inc. using the Quasi-Monte Carlo with Halton’s quasi-randomized sequence on the 1000000th simulation with a standard error of 0,045 is $90,163. The call option price obtained can be used as a reference for investors in purchasing options to minimize losses from call option investments in that period.

Effects of land use/cover changes on soil organic carbon stocks in Qinghai-Tibet plateau: A comparative analysis of different ecological functional areas based on machine learning methods and soil carbon pool data

Understanding the process of land use/cover changes (LUCC) can provide experience on the enhancement of soil organic carbon (SOC) stocks and carbon sequestration potential for different areas. This study is uniquely to divide different ecological functional areas, and originally combine the machine learning method and soil carbon pool dataset for regional comparative analysis, to compare and quantitatively analyze the drivers of LUCC and the changes in SOC stocks effected by LUCC over 30 years. The results show that topography and climate changes are the main drivers affecting LUCC in four natural areas, while soil factors and population changes do not cause significant effects. The total SOC stocks in Qinghai was increased by 71.18 Tg C and 107.19 Tg C in 0–30 cm and 0–300 cm layers, respectively, and the highest SOC stocks within 0–300 cm were in Pastoral area. Desert and Gobi area had the lowest SOC stocks in both 0–30 cm and 0–300 cm layers. SOC stocks increased in both 0–30 cm and 0–300 cm layers only in Sanjiangyuan Natural Reserve, while the Desert and Gobi area showed a decrease in both over 30 years. This study emphasizes the significant impact of grassland changes on SOC stocks, indicating the importance of considering these changes in land management and ecological protection policies. The initial and original SOC stocks of pre-LUCC may influence the SOC stocks in post-LUCC. The response of SOC stocks changes to LUCC was varies in different areas. The heterogeneity of different ecological functional areas is affected by multiple factors and SOC stocks will become more complex among these areas in the future. These findings contribute to the development of ecological protection policies and the enhancement of regional land management strategies.

Sustainable finance statistics: Progress, challenges and leveraging digital tools

Sustainable finance has attracted increased attention in recent years, and, in turn, the availability of relevant data has become a primary concern. What is currently unclear is how to set up adequate statistical frameworks, to address the associated challenges while benefitting from emerging new opportunities. Given their dual role as both compilers and users of official statistics, central banks are particularly well placed to contribute to these topics. Their experience suggests that making further progress calls for, first, understanding the importance of environmental, social and governance (ESG) issues for the conduct of economic and financial public policies and, second, carefully taking stock of the important statistical compilation initiatives already in train. The third step is to identify sustainable finance information needs and address the related data gaps. Lastly, there is value in leveraging the various opportunities provided by alternative data sources and technology innovation, including through the offering of new digital tools. This paper analyses central ESG issues.

The effect of continuous lighting on the rearing of yellowfin tuna (Thunnus albacares) larvae

Yellowfin tuna (Thunnus albacares) has important economic value in the world market. This study aims to determine the effect of continuous lighting on survival, growth, stomach contents, and histology of the eye of larvae. Larval rearing was conducted on 6 concrete tanks with 60 m3 in volume that support the water circulation and aeration system with an initial stocking of 20 eggs/liter. The treatments tested were A: Larval rearing by a 40-watt fluorescent lamp (TL) which was positioned 1 m above the surface of the water surface for 24 hours and B: Without lights (control). Each treatment used 3 repetitions and data analysis with a t-test. The parameters observed were larval survival and growth stomach content and eyes histology. The results showed that the rearing of larvae in treatment B can with a survival of 0.26±0.0231% and a final total length of 3 6.2 ± 7.3 mm which is significantly higher (P<0.05) compared to treatment A (0.10±0.057% and 24.3 ± 5.5 mm). From the observation of stomach contents at night in treatment B still eats rotifers while in treatment A stomach is empty. The inner nuclear layer cell arrangement of larval eyes is more tenuous than control. From these results, it can be concluded that the provision of continuous lighting treatment can improve the survival, growth, stomach content, and vision ability of larvae.

Optimal governance strategies for air pollution embodied in Sino-US trade: Evidence from a differential game model

The discussions between countries on trade inequality and ecological inequality have become increasingly heated, making cooperation on air pollution governance a priority. Based on the global multiregional input‒output (MRIO) model for calculating Sino-US trade-embodied air pollution (TEAP), an economic compensation mechanism is introduced into a differential game model. The main conclusions are as follows: (1) In bilateral Sino-US trade, the TEAP transferred from the United States to China is 6.85 times that transferred from China to the United States, showing serious ecological inequality. (2) The optimal TEAP emissions are influenced only by domestic factors in the noncooperative game, while they are jointly controlled by factors from both countries in the cooperative game. The optimal compensation coefficient is also influenced by factors from the two countries in the noncooperative game. In addition, the optimal TEAP stock and optimal investment stock are positively correlated with the initial stock under the two game scenarios. (3) Through numerical simulation, compared with the noncooperative game with economic compensation, the cooperative game without economic compensation can significantly reduce the optimal TEAP emissions and optimal TEAP stock; however, this reduction requires more governance investment. Consequently, China and the United States should comprehensively consider the advantages and disadvantages of the two governance strategies to maximize their overall economic benefits on the basis of basic fairness.

Development of Visible Spectrophotometric Method and its Validation for Dolutegravir in Tablet Dosage Form

Objective: There are several methods for analyzing the same, however, they are time-consuming and costly. We created a new spectrophotometric method for determining Dolutegravir (DLT) in tablet dosage forms that is simple, accurate, and precise. We developed and validated a simple, accurate, and precise colorimetric method for the quantitative analysis of Dolutegravir in bulk and dosage form by ICH recommendations in this study. Methodology: There are several methods for analyzing the same, however, they are time-consuming and costly. We created a new spectrophotometric method for determining Dolutegravir (DLT) in tablet dosage forms that is simple, accurate, and precise. In methanol, the initial stock solution of Dolutegravir was prepared. The method is based on the formation of a blue color chromogen complex from Dolutegravir oxidation-reduction with Ferric chloride in the presence of potassium ferricyanide. Result: The color complex was measured at 710nm. Beers law was observedin the concentration range of 3.5-6.5μg/ml witha coefficient of correlation (R2) was 0.998. The system suitability criteria were found to be within the limits. The LOD and LOQ were found to be 0.91 and 2.47, indicating that the method is sensitive. Conclusion: The relative standard deviation (RSD) and percent recovery values were found to be satisfactory, indicating that the proposed method is suitable, accurate, and precise and that it can be used in routine analysis of Dolutegravir in tablet dosage forms, with relatively low-cost solvents.

Applications of genetic algorithm in prediction of the best achievable combination of hardness and tensile strength for graphene reinforced magnesium alloy (AZ61) matrix composite

Due to lack of knowledge about role of process variables in the hot rolling of magnesium alloy composites, the most desirable wrought products of magnesium alloy-based composites could not be successfully produced till date. Moreover, use of wrought graphene reinforced magnesium alloy-based composite has emerged as a lucrative option for developing novel light alloy products in structural applications. The implicative need to obtain the best possible properties of the composite dictates to fix the optimized process variables in rolling operation. The present study envisages the development of data driven model that enables to derive desirable properties of the said composite; so, in order to secure the optimized subset of requirements (process parameters), a metaheuristic optimization tool is employed. We invoke the use of Genetic Algorithm (GA) optimizing tool in association with linear regression, so as to achieve the best combination of hardness and tensile strength of AZ-61-graphene nanoplate (GNP) composite.Modified magnesium AZ-61 alloy composites of varying GNP content (0, 1 and 2 wt.%) are produced by stir casting. The cast composites are homogenized at 450 °C for 12 h, followed by iced water quenching. The quenched materials are subjected to hot rolling and the process variables of hot rolling operation consist of rolling temperature, number of rolling passes as well as the initial stock thickness. The rolled materials are tested for hardness and tensile strength as the response variables. Instead of using artificial neural network to fix the objective function of GA, a mathematical model is developed by regression analysis; the derived equation is used as the objective function for multi-objective optimization task. The present paper explores the usefulness of implementing evolutionary algorithm (as in genetic algorithm) to correctly forecast the effect of rolling process variables onto the hardness and tensile strength of the stir cast AZ alloy-GNP nanocomposite.The experimental results show that the maximum achievable hardness value happens to be 106.6 VHN and is very close to that predicted by GA, ∼107.41VHN. Similarly, the maximum experimental tensile strength is found to be 266.82 MPa whereas, the corresponding GA predicted value is seen to be 253 MPa. A close fit can thus be noticed between the GA predicted and the experimentally obtained values. Barring a couple of exceptions, the difference between the experimental and GA predicted data lies within 1 % to 5 % (based on [Experimental value ∼ predicted value]/ [experimental value]). This entices to believe that the adopted muti-objective optimization strategy is quite useful in determining the optimum combination of rolling parameters that aids in achieving the most desirable property combination.

Social housing and the spread of population: Evidence from twentieth century Ireland

How does housing policy influence the long-run distribution of population? We examine the impact on long-term population dynamics of the world’s first large-scale rural public housing scheme, specifically the case of Ireland’s Labourers Acts. We link detailed data on the location of over 45,000 heavily subsidized cottages for agricultural laborers built 1883–1915 in over 200 districts to decennial Censuses between 1841 and 2002. We examine how the density of this social housing affected subsequent population change and find significant persistence in the effect of this treatment on the population. These findings are from specifications that include other factors plausibly related to future population growth, including initial housing stock, land values and population density, as well as distance to urban centres. A causal interpretation is supported by an assessment of pre-trends, by no effect of cottages authorized but not built and by an IV approach that exploits a 1906 limit on legal costs. We also highlight the role of agglomeration in amplifying the impact of the initial investment. Mediation analysis suggests that schooling was a key factor, with districts receiving more cottages less likely to lose primary schools, thus further influencing population growth.