Search results for: Rate of profit

Authors: Rachel Gough

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In 2014, Skellig Michael, an island off Ireland’s western seaboard and UNESCO world heritage site became a major setting in Disney’s Star Wars franchise. The subsequent influx of tourists to the site has proven to be a point of contention nationally. The increased visitor numbers have uplifted certain areas of the local economy, the mainland, but have caused irreparable damage to historic monuments and to endangered bird populations who breed on the island. Recent research carried out by a state body suggests far-reaching and longterm negative impacts on the island’s culture and environment, should the association with the Star Wars franchise persist. In spite of this, the film has been widely endorsed by the Irish government as providing a vital economic boost to historically marginalised rural areas through film tourism. This paper argues quite plainly that what is taking place on Skellig is neocolonialism. Skellig Michael’s unique resources, its aesthetic qualities, its ecosystem, and its cultural currency have been sold by the state to a multinational corporation, who profit from their use. Meanwhile, locals are left to do their best to turn a market trend into sustainable business at the expense of culture ecology and community. This paper intends to be the first dedicated study into the psychogeographic and cultural impact of Skellig Michael’s deterioration as a result of film tourism. It will discuss the projected impact of this incident on Irish culture more broadly and finally will attempt to lay out a roadmap for more collaborative filmmaking and touristic approach, which allows local cultures and ecosystem’s to thrive without drastically inhibiting cultural production. This paper will ultimately find that the consequences of this representation call for a requirement to read tourism as a split concept — namely into what we might loosely call “eco-tourism” and more capital-based “profit-bottom-line tourism.”

Keywords: ecology, film tourism, neocolonialism, sustainability

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Authors: A. S. Talaab, Safaa, A. Mahmoud, Hanan S. Siam

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A field experiment was conducted during the winter season of 2013/2014 in the barley production area of Dakhala – New Valley Governorate, Egypt to assess the effect of nitrogen rate and time of N fertilizer application on barley grain yield, yield components and N use efficiency of barley and their association with grain yield. The treatments consisted of three levels of nitrogen (0, 70 and 100 kg N/acre) and five application times. The experiment was laid out as a randomized complete block design with three replication. Results revealed that barley grain yield and yield components increased significantly in response to N rate. Splitting N fertilizer amount at several times result in significant effect on grain yield, yield components, protein content and N uptake efficiency when compared with the entire N was applied at once. Application of N at rate of 100 kg N/acre resulted in accumulation of nitrate in the subsurface soil > 30cm. When N application timing considered, less NO3 was found in the soil profile with splitting N application compared with all preplans application.

Keywords: nitrogen use efficiency, splitting N fertilizer, barley, NO3

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Authors: Amassoma Ditimi, Nwosa Philip Ifeakachukwu

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This study examined the impact of inflation on private investment in Nigeria for the period 1980 to 2012. Private investment was measured by foreign direct investment and private domestic investment. The study employed the Ordinary Least Square (OLS) technique. The empirical regression estimate showed that inflation had a positive but insignificant effect on private investment in Nigeria; implying that although an increase in inflation rate leads to a corresponding increase in private investment but however the effect was found to be insignificant. Thus, the study recommended that government should prevent high inflation rate that can negatively affect private investment in Nigeria and government should also put in place appropriate facilities that are investment enhancing in order to increase the level of both domestic and foreign private investment in Nigeria.

Keywords: inflation rate, private investment, OLS, Nigeria

Procedia PDF Downloads 346

Authors: Barkaoui Asma

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In our article, we use the economic approach of measuring advertising effectiveness to show the margin of advertising spread gained through digital communication. For economists, profit maximization depends on determining the optimal advertising budget. For this, they use the theories of the marginalist current to determine when the maximum level of benefits is reached. Using the economic approach we show the significant return on investment for advertisers. We then discuss the risks of perception of advertising pressure by consumers.

Keywords: digital advertising, economic approach, effectiveness, pressure

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Authors: Yongrong Liu, Xin Tang

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Background: Persistent atrial fibrillation is a common arrhythmia closely related to heart failure. Heart rate control is an essential strategy for treating persistent atrial fibrillation. Still, the understanding of the relationship between different heart rate control levels and the risk of heart failure rehospitalization is limited. Objective: The objective of the study is to determine the relationship between different levels of heart rate control in patients with persistent atrial fibrillation and the risk of readmission for heart failure. Methods: We conducted a retrospective dual-centre cohort study, collecting data from patients with persistent atrial fibrillation who received outpatient treatment at two tertiary hospitals in central and western China from March 2019 to March 2020. The collected data included age, gender, body mass index (BMI), medical history, and hospitalization frequency due to heart failure. Patients were divided into three groups based on their heart rate control levels: Group I with a resting heart rate of less than 80 beats per minute, Group II with a resting heart rate between 80 and 100 beats per minute, and Group III with a resting heart rate greater than 100 beats per minute. The readmission rates due to heart failure within one year after discharge were statistically analyzed using propensity score matching in a 1:1 ratio. Differences in readmission rates among the different groups were compared using one-way ANOVA. The impact of varying levels of heart rate control on the risk of readmission for heart failure was assessed using the Cox proportional hazards model. Binary logistic regression analysis was employed to control for potential confounding factors. Results: We enrolled a total of 1136 patients with persistent atrial fibrillation. The results of the one-way ANOVA showed that there were differences in readmission rates among groups exposed to different levels of heart rate control. The readmission rates due to heart failure for each group were as follows: Group I (n=432): 31 (7.17%); Group II (n=387): 11.11%; Group III (n=317): 90 (28.50%) (F=54.3, P<0.001). After performing 1:1 propensity score matching for the different groups, 223 pairs were obtained. Analysis using the Cox proportional hazards model showed that compared to Group I, the risk of readmission for Group II was 1.372 (95% CI: 1.125-1.682, P<0.001), and for Group III was 2.053 (95% CI: 1.006-5.437, P<0.001). Furthermore, binary logistic regression analysis, including variables such as digoxin, hypertension, smoking, coronary heart disease, and chronic obstructive pulmonary disease as independent variables, revealed that coronary heart disease and COPD also had a significant impact on readmission due to heart failure (p<0.001). Conclusion: The correlation between the heart rate control level of patients with persistent atrial fibrillation and the risk of heart failure rehospitalization is positive. Reasonable heart rate control may significantly reduce the risk of heart failure rehospitalization.

Keywords: heart rate control levels, heart failure rehospitalization, persistent atrial fibrillation, retrospective cohort study

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Authors: Harman Jaggi, David Steinsaltz, Shripad Tuljapurkar

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Understanding the effect of fluctuations on populations is crucial in the context of increasing habitat fragmentation, climate change, and biological invasions, among others. Migration in response to environmental disturbances enables populations to escape unfavorable conditions, benefit from new environments and thereby ride out fluctuations in variable environments. Would populations disperse if there is no uncertainty? Karlin showed in 1982 that when sub-populations experience distinct but fixed growth rates at different sites, greater mixing of populations will lower the overall growth rate relative to the most favorable site. Here we ask if and when environmental variability favors migration over no-migration. Specifically, in random environments, would a small amount of migration increase the overall long-run growth rate relative to the zero migration case? We use analysis and simulations to show how long-run growth rate changes with migration rate. Our results show that when fitness (dis)advantages fluctuate over time across sites, migration may allow populations to benefit from variability. When there is one best site with highest growth rate, the effect of migration on long-run growth rate depends on the difference in expected growth between sites, scaled by the variance of the difference. When variance is large, there is a substantial probability of an inferior site experiencing higher growth rate than its average. Thus, a high variance can compensate for a difference in average growth rates between sites. Positive correlations in growth rates across sites favor less migration. With multiple sites and large fluctuations, the length of shortest cycle (excursion) from the best site (on average) matters, and we explore the interplay between excursion length, average differences between sites and the size of fluctuations. Our findings have implications for conservation biology: even when there are superior sites in a sea of poor habitats, variability and habitat quality across space may be key to determining the importance of migration.

Keywords: migration, variable-environments, random, dispersal, fluctuations, habitat-quality

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Authors: Jinyoung Kim, Jinuk Kwon, Haksoo Han

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Polyimide is widely used in electronic industries, and heat dissipation of polyimide film is important for its application in electric devices for high-temperature resistance heat dissipation film. In this study, we demonstrated a new way to increase heat dissipating rate by adding carbon black as filler. This type of polyimide composite film was produced by pyromellitic dianhydride (PMDA) and 4,4’-oxydianiline (ODA). Carbon black (CB) is added in different loading, shows increasing heat dissipation rate for increase of Carbon black. The polyimide-carbon black composite film is synthesized with high dissipation rate to ~8W∙m−1K−1. Its high thermal decomposition temperature and glass transition temperature were maintained with carbon filler verified by thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC), the polyimidization reaction of polyi(amide-mide) was confirmed by Fourier transform infrared spectroscopy (FT-IR). The polyimide composite film with carbon black with high heat dissipating rate could be used in various applications such as computers, mobile phone industries, integrated circuits, coating materials, semiconductor etc.

Keywords: polyimide, heat dissipation, electric device, filler

Procedia PDF Downloads 657

Authors: Man Chul Jeong, Hyoung Jin Lee, Sang Yoon Lee, Ji Hyun Park, Min Wook Chang, In-Seuck Jeung

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This study focus on the drag reduction effect of the base bleed at supersonic flow. Base bleed is the method which bleeds the gas on the tail of the flight vehicle and reduces the base drag, which occupies over 50% of the total drag in any flight speed. Thus base bleed can reduce the total drag significantly, and enhance the total flight range. Drag reduction ratio of the base bleed is strongly related to the mass flow rate of the bleeding gas. Thus selecting appropriate mass flow rate is important. However, since the flight vehicle has various flight speed, same mass flow rate of the base bleed can have different drag reduction effect during the flight. Thus, this study investigates the effect of the drag reduction depending on the flight speed by numerical analysis using STAR-CCM+. The analysis model is 155mm diameter projectile with boat-tailed shape base. Angle of the boat-tail is chosen previously for minimum drag coefficient. Numerical analysis is conducted for Mach 2 and Mach 3, with various mass flow rate, or the injection parameter I, of the bleeding gas and the temperature of the bleeding gas, is fixed to 300K. The results showed that I=0.025 has the minimum drag at Mach 2, and I=0.014 has the minimum drag at Mach 3. Thus as the Mach number is higher, the lower mass flow rate of the base bleed has more effect on drag reduction.

Keywords: base bleed, supersonic, drag reduction, recirculation

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Authors: Gobena D. Bayisa, A. Mekonen, Megersa O. Dinka, Tilahun H. Nebi, M. Boja

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Crop production in arid and semi-arid regions of Ethiopia is largely limited by water availability. Changing climate conditions and declining water resources increase the need for appropriate approaches to improve water use and find ways to increase production through reduced and more reliable water supply. In the years 2021/22 and 2022/23, a field experiment was conducted to evaluate the effect of limited irrigation water use on bread wheat (Triticum aestivum L.) production, water use efficiency, and financial benefits. Five irrigation treatments, i.e., full irrigation (100% ETc/ control), 85% ETc, 70% ETc, 55% ETc, and 40% ETc, were evaluated using a randomized complete block design (RCBD) with four replicates in the semi-arid climate condition of Awash basin of Ethiopia. Statistical analysis showed a significant effect of irrigation levels on wheat grain yield, water use efficiency, crop water response factor, economic profit, wheat grain quality, aboveground biomass, and yield index. The highest grain yield (5085 kg ha⁻¹) was obtained with 100% ETc irrigation (417.2 mm), and the lowest grain yield with 40% ETc (223.7 mm). Of the treatments, 70% ETc produced the higher wheat grain yield (4555 kg ha⁻¹), the highest water use efficiency (1.42 kg m⁻³), and the highest yield index (0.43). Using the saved water, wheat could be produced 23.4% more with a 70% ETc deficit than full irrigation on 1.38 ha of land, and it could get the highest profit (US$2563.9) and higher MRR (137%). The yield response factor and crop-water production function showed potential reductions associated with increased irrigation deficits. However, a 70% ETc deficit is optimal for increasing wheat grain yield, water use efficiency, and economic benefits of irrigated wheat production. The result indicates that deficit irrigation of wheat under the typical arid and semi-arid climatic conditions of the Awash Basin can be a viable irrigation management approach for enhancing water use efficiency while minimizing the decrease in crop yield could be considered effective.

Keywords: crop-water response factor, deficit irrigation, water use efficiency, wheat production

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Authors: Abdulrahman K. Alshegaifi, Chun-Hsi Huang

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Treating data based on its location in memory has received much attention in recent years due to its different properties, which offer important aspects for cache utilization. Stack data and non-stack data may interfere with each other’s locality in the data cache. One of the important aspects of stack data is that it has high spatial and temporal locality. In this work, we simulate non-unified cache design that split data cache into stack and non-stack caches in order to maintain stack data and non-stack data separate in different caches. We observe that the overall hit rate of non-unified cache design is sensitive to the size of non-stack cache. Then, we investigate the appropriate size and associativity for stack cache to achieve high hit ratio especially when over 99% of accesses are directed to stack cache. The result shows that on average more than 99% of stack cache accuracy is achieved by using 2KB of capacity and 1-way associativity. Further, we analyze the improvement in hit rate when adding small, fixed, size of stack cache at level1 to unified cache architecture. The result shows that the overall hit rate of unified cache design with adding 1KB of stack cache is improved by approximately, on average, 3.9% for Rijndael benchmark. The stack cache is simulated by using SimpleScalar toolset.

Keywords: hit rate, locality of program, stack cache, stack data

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Authors: E. Kharaishvili, M. Chavleishvili, M. Lobzhanidze, N. Damenia, N. Sagareishvili

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The article substantiates that youth employment in Georgia, especially in the agricultural sector, is an acute socio-economic problem. The paper analyzes the indicators of youth employment and unemployment rates by age and gender in the agriculture sector. Research revealed that over the past decade, the unemployment rate in rural areas has decreased; however, the problem of unemployment is more sensitive than in the city in this field. The article established youth unemployment rates in rural areas; it assesses labor and educational migration causes. Based on the survey, there are proposed findings and recommendations of the agricultural sector about improving youth employment, reducing unemployment rate, reaching migration processes optimization.

Keywords: youth employment, the agricultural sector, unemployment rate, youth migration, agricultural education

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Authors: Yu A. Pluttsova , O. V. Vakhnina , K. B. Zhogova

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Nowadays, many devices operate under conditions of enhanced humidity, temperature drops, fog, and vibration. To ensure long-term and uninterruptable equipment operation under adverse conditions, one applies moisture-proof films on products and electronics components, which helps to prevent corrosion, short circuit, allowing a significant increase in device lifecycle. The reliability of such moisture-proof films is mainly determined by their coating uniformity without gaps and cracks. Unprotected product edges, as well as pores in films, can cause device failure during operation. The work objective was to develop an effective, affordable, and profit-proved method for determining the presence of through defects of protective polymer films on the surface of parts made of iron and its alloys. As a diagnostic reagent, one proposed water solution of potassium ferricyanide (III) in hydrochloric acid, this changes the color from yellow to blue according to the reactions; Feº → Fe²⁺ and 4Fe²⁺ + 3[Fe³⁺(CN)₆]³⁻ → Fe ³⁺4[Fe²⁺(CN)₆]₃. There was developed the principle scheme of technological process for determining the presence of polymer films through defects on the surface of parts made of iron and its alloys. There were studied solutions with different diagnostic reagent compositions in water: from 0,1 to 25 mass fractions, %, of potassium ferricyanide (III), and from 5 to 25 mass fractions, %, of hydrochloride acid. The optimal component ratio was chosen. The developed method consists in submerging a part covered with a film into a vessel with a diagnostic reagent. In the polymer film through defect zone, the part material (ferrum) interacts with potassium ferricyanide (III), the color changes to blue. Pilot samples were tested by the developed method for the presence of through defects in the moisture-proof coating. It was revealed that all the studied parts had through defects of the polymer film coating. Thus, the claimed method efficiently reveals polymer film coating through defects on parts made of iron or its alloys, being affordable and profit-proved.

Keywords: diagnostic reagent, metal parts, polimer films, through defects

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Authors: Diptimayee Nayak, V. Upadhyay

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This paper posits the attempt of conservation and the idea of protected areas from the Marxian primitive accumulation to the politics of sustainability. Using field survey data and secondary literature, this paper analyses an Indian wildlife sanctuary, the Bhitarkanika, Odisha and finds how the hegemony of power among different management regimes attempted for conservation and the present protected area management regime attempted to imbibe the policy of ecotourism for achieving sustainability. The paper contends that the current policy of ecotourism in protected areas acts as a veil for the local deprived people, to avoid many legal conflicts like property rights, livelihood, and man-wildlife issues. Moreover, opening the scope to accumulate on the part of tour operators, the policy of ecotourism establishes a nexus between the profit holders/tour operators (the capitalists) and the power hegemony on the part of management authorities. The sustainability attempt of ecotourism may lead to private benefits maximising the profit accumulation and can expand and continue, showing the bulk of employment generation of local people at petty odd jobs, grabbing a lion share! Positing ecotourism as a capitalist project as against the general assumption of one of the drivers of sustainable development, the paper shows that ecotourism in practice may end up ruining the very social-environmental set up, leading to unsustainability related to waste management, equality, culture, relationship and above all polarised private accumulators in absence of sound mechanism. The paper ends with the caveat that while shopping for neoliberal conservation, the conservators found ecotourism as a product without finalising the hallmark of mechanism/ institutions with appropriate modus operandii to check/guard the quality assurance/standard of ecotourism for sustainability. The paper proposes sound structural and institutional mechanism of ecotourism to be developed to harness sustainability in the local economy as well as in conservation.

Keywords: conservation, ecotourism, Marxian capitalism, protected areas, sustainability

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Authors: Michael Dreyfuss, Yahel Giat

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Limited battery range and long recharging times are the greatest obstacles to the successful adoption of electric cars. One of the suggestions to overcome these problems is that carmakers retain ownership of batteries and provide battery swapping service so that customers exchange their depleted batteries for recharged batteries. Motivated by this example, we consider the problem of optimal spares allocation in an exchangeable-item, multi-location repair system. We generalize the standard service measures of fill rate and average waiting time to reflect the fact that customers penalize the service provider only if they have to wait more than a ‘tolerable’ time window. These measures are denoted as the window fill rate and the truncated waiting time, respectively. We find that the truncated waiting time is convex and therefore a greedy algorithm solves the spares allocation problem efficiently. We show that the window fill rate is generally S-shaped and describe an efficient algorithm to find a near-optimal solution and detail a priori and a posteriori upper bounds to the distance from optimum. The theory is complemented with a large scale numerical example demonstrating the spare battery allocation in battery swapping stations.

Keywords: convex-concave optimization, exchangeable item, M/G/infinity, multiple location, repair system, spares allocation, window fill rate

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Authors: A. Preetha Priyadharshini, S. B. M. Priya

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In this paper, we consider the MU-MISO downlink scenario, under imperfect channel state information (CSI). The main issue in imperfect CSI is to keep the probability of each user achievable outage rate below the given threshold level. Such a rate outage constraints present significant and analytical challenges. There are many probabilistic methods are used to minimize the transmit optimization problem under imperfect CSI. Here, decomposition based large deviation inequality and Bernstein type inequality convex restriction methods are used to perform the optimization problem under imperfect CSI. These methods are used for achieving improved output quality and lower complexity. They provide a safe tractable approximation of the original rate outage constraints. Based on these method implementations, performance has been evaluated in the terms of feasible rate and average transmission power. The simulation results are shown that all the two methods offer significantly improved outage quality and lower computational complexity.

Keywords: imperfect channel state information, outage probability, multiuser- multi input single output, channel state information

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Authors: Pushkar Lal Sharma, Sanjana Singh, Umesh Kumar Sahu

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This paper helps to understand the need of Customer Relationship Management in Libraries and why Librarians should implement the marketing concept of Customer Relationship Management in their libraries. As like any industry, libraries too face growing challenges to continuously meet customer expectations, and attract and retain users in light of overflowing competition. The ability to understand customers, build relationships and market diverse services is essential when considering ways to expand service offerings and improve Return on Investment. Since Library is service oriented Enterprise, hence the Customer/User/ Reader/Patron are the most important element of Library & Information System to whom and for whom library offers various services. How to provide better and most efficient services to its users is the main concern of every Library & Information centre in the present era. The basic difference between Business Enterprise and Library Information System is that ‘in Business System ‘the efficiency is measured in terms of ’profit’ or ‘monetary gains’; whereas in a Library & Information System, the efficiency is measured in terms of ‘services’ and therefore the goals that are set in Business Enterprise are’ profit oriented’ whereas goals set in the Library & Information Centre are ‘Service-oriented’. With the explosion of information and advancement of technology readers have so many choices to get information rather than visiting a library. Everything is available at the click of a mouse, library customers have become more knowledgeable and demanding in an era marked by abundance of information resources and services. With this explosion of information in every field of knowledge and choice in selection of service, satisfying user has become a challenge now a day for libraries. Accordingly, Libraries have to build good relationship with its users by adopting Customer relationship Management. CRM refers to the methods and tools which help an organization to manage its relationship with its customers in an organized way. The Customer Relationship Management (CRM) combines business strategy and technology to identify, acquire and retain good customer relationship. The goal of CRM is to optimize management of customer information needs & interests and increase customer satisfaction and loyalty. Implementing CRM in Libraries can improve customer data and process management, customer loyalty, retention and satisfaction.

Keywords: customer relationship management, CRM, CRM tools, customer satisfaction

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Authors: Shahin A. Abdel-Naby, Asad T. Hassan, Stuart Loch, Michael Fogle, Negil R. Badnell, Michael S. Pindzola

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Accurate and reliable laboratory astrophysical data for electron-ion recombination are needed for plasma modeling. Dielectronic recombination (DR) rate coefficients are calculated for boron-like nitrogen and oxygen ions using state-of-the-art multi-configuration Breit-Pauli atomic structure AUTOSTRUCTURE collisional package within the generalized collisional-radiative framework. The calculations are performed in intermediate coupling scheme associated with n = 0 (2  2) and n = 1 (2  3) core-excitations. Good agreements are found between the theoretically convoluted rate coefficients and the experimental measurements performed at CRYRING heavy-ion storage ring for both ions. Fitting coefficients for the rate coefficients are produced for these ions in the temperature range q2(102-107) K, where q is the ion charge before recombination.

Keywords: Atomic data, atomic processes, electron-ion collision, plasma

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Authors: Wale Agbaje

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The aim of this research study is to assess the impact of financial statement fraud on profitability of some selected Nigerian manufacturing firms covering (2002-2016). The specific objectives focused on to ascertain the effect of incorrect asset valuation on return on assets (ROA) and to ascertain the relationship between improper expense recognition and return on assets (ROA). To achieve these objectives, descriptive research design was used for the study while secondary data were collected from the financial reports of the selected firms and website of security and exchange commission. The analysis of covariance (ANCOVA) was used and STATA II econometric method was used in the analysis of the data. Altman model and operating expenses ratio was adopted in the analysis of the financial reports to create a dummy variable for the selected firms from 2002-2016 and validation of the parameters were ascertained using various statistical techniques such as t-test, co-efficient of determination (R2), F-statistics and Wald chi-square. Two hypotheses were formulated and tested using the t-statistics at 5% level of significance. The findings of the analysis revealed that there is a significant relationship between financial statement fraud and profitability in Nigerian manufacturing industry. It was revealed that incorrect assets valuation has a significant positive relationship and so also is the improper expense recognition on return on assets (ROA) which serves as a proxy for profitability. The implication of this is that distortion of asset valuation and expense recognition leads to decreasing profit in the long run in the manufacturing industry. The study therefore recommended that pragmatic policy options need to be taken in the manufacturing industry to effectively manage incorrect asset valuation and improper expense recognition in order to enhance manufacturing industry performance in the country and also stemming of financial statement fraud should be adequately inculcated into the internal control system of manufacturing firms for the effective running of the manufacturing industry in Nigeria.

Keywords: Althman's Model, improper expense recognition, incorrect asset valuation, return on assets

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Authors: Salma Parvin, M. A. Alim

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The convective and radiative heat transfer performance and entropy generation on forced convection through a direct absorption solar collector (DASC) is investigated numerically. Four different fluids, including Cu-water nanofluid, Al₂O₃-waternanofluid, TiO₂-waternanofluid, and pure water are used as the working fluid. Entropy production has been taken into account in addition to the collector efficiency and heat transfer enhancement. Penalty finite element method with Galerkin’s weighted residual technique is used to solve the governing non-linear partial differential equations. Numerical simulations are performed for the variation of mass flow rate. The outcomes are presented in the form of isotherms, average output temperature, the average Nusselt number, collector efficiency, average entropy generation, and Bejan number. The results present that the rate of heat transfer and collector efficiency enhance significantly for raising the values of m up to a certain range.

Keywords: DASC, forced convection, mass flow rate, nanofluid

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Authors: Mohieddine Benghersallah, Lakhdar Boulanouar, Salim Belhadi

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Currently, higher production rate with required quality and low cost is the basic principle in the competitive manufacturing industry. This is mainly achieved by using high cutting speed and feed rates. Elevated temperatures in the cutting zone under these conditions shorten tool life and adversely affect the dimensional accuracy and surface integrity of component. Thus it is necessary to find optimum cutting conditions (cutting speed, feed rate, machining environment, tool material and geometry) that can produce components in accordance with the project and having a relatively high production rate. Response surface methodology is a collection of mathematical and statistical techniques that are useful for modelling and analysis of problems in which a response of interest is influenced by several variables and the objective is to optimize this response. The work presented in this paper examines the effects of cutting parameters (cutting speed, feed rate and depth of cut) on to the surface roughness through the mathematical model developed by using the data gathered from a series of milling experiments performed.

Keywords: Statistical analysis (RSM), Bearing steel, Coating inserts, Tool life, Surface Roughness, End milling.

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Authors: Azhar Abdul Rahman

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This paper examines the readability of the chairman’s narratives, as determined by the Flesch score, of a Malaysian public listed company’s corporate reports from 1962 to 2009. It partially supports earlier studies which demonstrated that corporate reports were difficult to read, and had shown very negligible decrease in difficulty over time. Net profit to sales and readability was significantly positively correlated but number of financial statements was significantly negatively correlated with readability.

Keywords: chairman’s narratives, corporate communications, readability, longitudinal

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Authors: Arun Goel

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The present paper attempts to investigate the prediction of air entrainment rate and aeration efficiency of a free over-fall jets issuing from a triangular sharp crested weir by using regression based modelling. The empirical equations, support vector machine (polynomial and radial basis function) models and the linear regression techniques were applied on the triangular sharp crested weirs relating the air entrainment rate and the aeration efficiency to the input parameters namely drop height, discharge, and vertex angle. It was observed that there exists a good agreement between the measured values and the values obtained using empirical equations, support vector machine (Polynomial and rbf) models, and the linear regression techniques. The test results demonstrated that the SVM based (Poly & rbf) model also provided acceptable prediction of the measured values with reasonable accuracy along with empirical equations and linear regression techniques in modelling the air entrainment rate and the aeration efficiency of a free over-fall jets issuing from triangular sharp crested weir. Further sensitivity analysis has also been performed to study the impact of input parameter on the output in terms of air entrainment rate and aeration efficiency.

Keywords: air entrainment rate, dissolved oxygen, weir, SVM, regression

Procedia PDF Downloads 407

Authors: H. Shokouhmand, M. Degheh, B. Sajadi, H. Sobhani

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The induct ultraviolet germicidal irradiation (UVGI) systems are broadly used nowadays and their utilization is widened every day. Even though these systems are not applicable individually, they are very suitable supplements for the traditional filtration systems. The amount of inactivated microorganisms is dependent on the air velocity, lamp power, fluence rate distribution, and also germicidal susceptibility of microorganisms. In this paper, these factors are investigated utilizing an air-microorganism two-phase numerical model. The eulerian-lagrangian method was used to have more detailed information on the history of each particle. The UVGI system was modeled in three steps including: 1) modeling the air flow, 2) modeling the discrete phase of particles, 3) modeling the UV intensity field, and 4) modeling the particle inactivation. The results from modeling different lamp arrangements and powers showed that the system functions better at more homogeneous irradiation distribution. Since increasing the air flow rate of the device results in increasing of particle inactivation rate, the optimal air velocity shall be adjusted in accordance with the microorganism production rate, and the air quality requirement using the curves represented in this paper.

Keywords: CFD, microorganism, two-phase flow, ultraviolet germicidal irradiation

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Authors: Mariana P. Medeiros, Amanda P. Carvallo, Augusta Isaac, Milos Janecek, Peter Minarik, Mayerling Martinez Celis, Roberto. R. Figueiredo

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The effect of high pressure torsion processing on mechanical properties and corrosion behavior of pure magnesium and Mg-Zn, Mg-Zn-Ca, Mg-Li-Y, and Mg-Y-RE alloys is investigated. Micro-tomography and SEM characterization are used to estimate corrosion rate and evaluate non-uniform corrosion features. The results show the severe plastic deformation processing improves the strength of all magnesium alloys, but deformation localization can take place in the Mg-Zn-Ca and Mg-Y-RE alloys. The occurrence of deformation localization is associated with low strain rate sensitivity in these alloys and with severe corrosion localization. Pure magnesium and Mg-Zn and Mg-Li-Y alloys display good corrosion resistance with low corrosion rate and maintained integrity after 28 days of immersion in Hank`s solution.

Keywords: magnesium alloys, severe plastic deformation, corrosion, biodegradable alloys

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Authors: Vipulkumar Jagodana

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Recently the use of renewable sources has increased, these sources include fuel cell, photo voltaic, and wind turbine. Islanding occurs when one portion of grid is isolated from remaining grid. Use of the renewable sources can provide continuous power to isolated portion in islanding condition. One of the common renewable sources is wind generation using wind turbine. The efficiency of wind generation can be increased in combination with conventional sources. When islanding occurs, few parameters change which may be frequency, voltage, active power, and harmonics. According to large change in one of these parameters islanding is detected. In this paper, two passive methods Rate of Change of Frequency (ROCOF) and Rate of change of Power (ROCOP) have been implemented for islanding detection of small wind-turbine. Islanding detection of both methods have been simulated in PSCAD. Simulation results show at different islanding inception angle response of ROCOF and ROCOP.

Keywords: islanding, adopted methods, PSCAD simulation, comparison

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Authors: Rebecca Dunne, Cormac Small, Geraldine O'Boyle, Nazir Ibrahim, Anisha

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Prostate cancer is the most common cancer among men, excluding non-melanoma skin cancers. It is estimated that approximately 12% of men will develop prostate cancer during their lifetime. Patients with intermediate, high risk, and very-high risk prostate cancer often undergo a combination of radiation treatments. These treatments include external beam radiotherapy with a low-dose rate or high-dose rate brachytherapy boost, often with concomitant androgen deprivation therapy. The literature on follow-up of patients that receive brachytherapy is scarce, particularly follow-up of patients that undergo high-dose rate brachytherapy. This retrospective study aims to investigate the biochemical failure and toxicities associated with triple therapy and external beam radiotherapy given in combination with brachytherapy. Reported toxicities and prostate specific antigen (PSA) were retrospectively evaluated in eighty patients that previously underwent external beam radiotherapy with a low-dose rate or high dose-rate brachytherapy boost. The severity of toxicities were correlated with intra-operative dosing during brachytherapy on ultrasound and CT scan. The results of this study will provide further information for clinicians and patients when considering treatment options.

Keywords: toxicities, combination, brachytherapy, intra-operative dosing, biochemical failure

Procedia PDF Downloads 206

Authors: Ali Maji

Abstract:

Highway development is an important factor for economic growth and development in both developed and developing countries. In Nigeria about two-third of transportation of goods and persons are done through highway network. It was this that made highway investment to enjoy position of relative high priority on the list of government expenditure programmes in Nigeria today. The paper noted that despite expansion of public investment in highway construction and maintenance of them, road traffic accident is increasing rate. This has acted as a drain of human capital which is a key to economic growth and development in Nigeria. In order to avoid this, the paper recommend introduction of Highway Safety Education (HSE) in Nigerian’s education system and investment in train transportation among other as a sure measure for curtailing highway accident.

Keywords: accident rate, high way development, human capital, national development

Procedia PDF Downloads 263

Authors: Deniz Dincel, Sena Ardicli, Hale Samli, Mustafa Ogan, Faruk Balci

Abstract:

The aim of the study was to determine the effects of some environmental and genetic factors on growth, fertility traits, milk yield and composition in Saanen goats. For this purpose, the total of 173 Saanen goats and kids were investigated for growth, fertility and milk traits in Marmara Region of Turkey. Fertility parameters (n=70) were evaluated during two years. Milk samples were collected during the lactation and the milk yield/components (n=59) of each goat were calculated. In terms of CSN3 and AGPAT6 gene; the genotypes were defined by PCR-RFLP. Saanen kids (n=86-112) were measured from birth to 6 months of life. The birth, weaning, 60ᵗʰ, 90ᵗʰ, 120ᵗʰ and 180tᵗʰ days of average live weights were calculated. The effects of maternal age on pregnancy rate (p < 0.05), birth rate (p < 0.05), infertility rate (p < 0.05), single born kidding (p < 0.001), twinning rate (p < 0.05), triplet rate (p < 0.05), survival rate of kids until weaning (p < 0.05), number of kids per parturition (p < 0.01) and number of kids per mating (p < 0.01) were found significant. The impacts of year on birth rate (p < 0.05), abortion rate (p < 0.001), single born kidding (p < 0.01), survival rate of kids until weaning (p < 0.01), number of kids per mating (p < 0.01) were found significant for fertility traits. The impacts of lactation length on all milk yield parameters (lactation milk, protein, fat, totally solid, solid not fat, casein and lactose yield) (p < 0.001) were found significant. The effects of age on all milk yield parameters (lactation milk, protein, fat, total solid, solid not fat, casein and lactose yield) (p < 0.001), protein rate (p < 0.05), fat rate (p < 0.05), total solid rate (p < 0.01), solid not fat rate (p < 0.05), casein rate (p < 0.05) and lactation length (p < 0.01), were found significant too. However, the effect of AGPAT6 gene on milk yield and composition was not found significant in Saanen goats. The herd was found monomorphic (FF) for CSN3 gene. The effects of sex on live weights until 90ᵗʰ days of life (birth, weaning and 60ᵗʰ day of average weight) were found significant statistically (p < 0.001). The maternal age affected only birth weight (p < 0,001). The effects month at birth on all of the investigated day [the birth, 120ᵗʰ, 180ᵗʰ days (p < 0.05); the weaning, 60ᵗʰ, 90ᵗʰ days (p < 0,001)] were found significant. The birth type was found significant on the birth (p < 0,001), weaning (p < 0,01), 60ᵗʰ (p < 0,01) and 90ᵗʰ (p < 0,01) days of average live weights. As a result, screening the other regions of CSN3, AGPAT6 gene and also investigation the phenotypic association of them should be useful to clarify the efficiency of target genes. Environmental factors such as maternal age, year, sex and birth type were found significant on some growth, fertility and milk traits in Saanen goats. So consideration of these factors could be used as selection criteria in dairy goat breeding.

Keywords: fertility, growth, milk yield, Saanen goats

Procedia PDF Downloads 143

Authors: R. Marandi, H. Shahrir, T. Nejad Ghaffar Borhani, M. Kamaruddin

Abstract:

In the present study, a steady state population balance model was developed to predict the polymer particle size distribution (PSD) in ethylene gas phase fluidized bed olefin polymerization reactors. The multilayer polymeric flow model (MPFM) was used to calculate the growth rate of a single polymer particle under intra-heat and mass transfer resistance. The industrial plant data were used to calculate the growth rate of polymer particle and the polymer PSD. Numerical simulations carried out to describe the influence of effective monomer diffusion coefficient, polymerization rate and initial catalyst size on the catalyst particle growth and final polymer PSD. The results present that the intra-heat and mass limitation is important for the ethylene polymerization, the growth rate of particle and the polymer PSD in the fluidized bed reactor. The effect of the agglomeration on the PSD is also considered. The result presents that the polymer particle size distribution becomes broader as the agglomeration exits.

Keywords: population balance, olefin polymerization, fluidized bed reactor, particle size distribution, agglomeration

Procedia PDF Downloads 309

Authors: R. S. Rajpurohit, N. C. Santhi Srinivas, Vakil Singh

Abstract:

Asymmetric stress cycling leads to accumulation of plastic strain which is called as ratcheting strain. The problem is generally associated with nuclear fuel cladding materials used in nuclear power plants and pressurized pipelines. In the present investigation, asymmetric stress controlled fatigue tests were conducted with three different parameters namely, mean stress, stress amplitude and stress rate (keeping two parameters constant and varying third parameter) to see the plastic strain accumulation and its effect on fatigue life and deformation behavior of Zircaloy-2 at 400°C. The tests were conducted with variable mean stress (45-70 MPa), stress amplitude (95-120 MPa) and stress rate (30-750 MPa/s) and tested specimens were characterized using transmission and scanning electron microscopy. The experimental results show that with the increase in mean stress and stress amplitude, the ratcheting strain accumulation increases with reduction in fatigue life. However, increase in stress rate leads to improvement in fatigue life of the material due to small ratcheting strain accumulation. Fractographs showed a decrease in area fraction of fatigue failed region.

Keywords: asymmetric cyclic loading, ratcheting fatigue, mean stress, stress amplitude, stress rate, plastic strain

Procedia PDF Downloads 238