CFD Simulation on Improving Water Quality based on Various Aerator Models to Demonstrate Cost Performance Analysis

There are many types of aerator that can be used to perform a water treatment process either from air to water or from water to air approaches. Other than focusing on the performance itself, the usage cost of aerator should be forecasted in detail too to have a sustainable and economical method in remediating the polluted water. Therein, the cost performance analysis was demonstrated by performing a computational fluid dynamics (CFD) simulation on improving water quality based on various aerator models. The simulation was focused in a small-scale aeration tank that consists of a mixing chamber, air duct, and a few of bubble diffusers. The improvement of water quality was assessed by calculating the number of gas bubble particles produced by 4 different configurations of aerator model, namely aerator model A, B, C and D, respectively. Results found that the aerator model D (5 bubble diffuser at 620 L/min) produces the highest number of gas particles up to 72.2%. However, the aerator model C (5 bubble diffuser at 300 L/min) was found to achieve the most efficient and sustainable approach based on energy consuming and cost of aerator configuration when compared to the other aerator models.

Desalination of Agricultural Wastewater by Solar Adsorption System: A Numerical Study

There are still areas around the world suffer from severe shortage of freshwater supplies. Desalination technologies are not widely used due to their high energy usage, cost, and environmental damaging effects. In this study, a mathematical model of single-bed adsorption desalination system using silica gel-water as working pair is developed and validated via earlier experiments. A very good match between the model predictions and the experimental results is recorded. The objective is to reveal the factors affecting the productivity of fresh water and cooling effect in the solar adsorption system. The proposed model is setup for solving within the commercially-available software (Engineering Equation Solver). It is implemented to solve the mass and heat balance equations for the adsorbent bed, condenser, and evaporator components. At a typical temperature of 89 °C and flow rate of 30 m3/sec for the hot water entering the bed, the following results are reported: (a) the specific daily water production of 1.89 m3 /ton of silica gel/ day, (b) coefficient of performance of 0.32, and (c) specific cooling power of 40.82 W/kg of silica gel. The concentration of salt (X) in the product (desalinated water) has been set with value of 0.5 gm/kg to be suitable for drinking and irrigation. The salt concentration in the evaporator is estimated to be 4.611 gm/kg during the overall adsorption process. The results from this study should be of wide interest for the field of solar water desalination and air-conditioning.

Design and Characterization of an Asynchronous Fixed Priority Tree Arbiter for SPAD Array Readout

The usage of single-photon avalanche diode arrays is becoming increasingly common in various domains such as medical imaging, automotive vision systems, and optical communications. Nowadays, thanks to the development of microelectronics technologies, the SPAD arrays designed for these applications has been drastically well-facilitated, allowing for the manufacturing of large matrices. However, there are growing challenges for the design of readout circuits with the needs of reducing their energy consumption (linked to the usage cost) and data rate. Indeed, the design of the readout circuit for the SPAD array is generally based on synchronous logic; the latter requires synchronization that may increase the dead time of the SPADs and clock trees management that are known to increase power consumption. With these limitations, the long-neglected asynchronous (clockless) logic proved to be a better alternative because of its ability to operate without a clock. In this paper, we presented the design of a 16-to-1 fixed-priority tree arbiter readout circuit for a SPAD array based on asynchronous logic principles. The design of this circuit was explained in detail and supported by simulation results. The manufactured chip was tested, and the experimental results showed that it is possible to record up to 333 million events per second; no reading errors were detected during the data extraction test.

Business Intelligence-Driven Supply Chain Optimization in Emerging Markets

Organizations produce churns of complex, opaque, and meaningless data. Business intelligence systems (BIS) help organizations efficiently use their data in promptly making quality decisions. The limitations of conventional BIS in processing the volume, variety, and veracity of data available in organizations and the operational cost of maintaining its infrastructure gave rise to implementing Cloud BIS, which describes the deployment of BIS over the cloud platform enabling resource elasticity, moderate usage cost, unlimited resources, and offering greater value at a reduced cost than the traditional BIS. BIS aids a productive supply chain and given the complexities of Africa's supply chain and high volatility of its business environment, BIS over the cloud platform would be a great enabler. This chapter aims to provide an understanding of how BIS will transform supply chain management in Africa's emerging market.

Quantitative Measure of Sustainability for Water Distribution Systems: A Comprehensive Review

This work provides a comprehensive review of the quantitative measures of sustainability proposed for water distribution systems (WDSs) and their sustainable development. After a comprehensive literature review, eighteen studies overall, either clearly proposing quantitative measures of sustainability (three studies) or highlighting sustainable development (fifteen studies), were selected for a closer review. All three measures showed either a lack of applicability or were missing important aspects of sustainability. Additionally, they have not been thoroughly validated by demonstrating the measures under acceptable scenarios/conditions. The reviewed sustainable development practices showed that energy usage and greenhouse gas emissions, life cycle costing, and reliability were widely used to evaluate environmental, economic, and social impacts, respectively. The two primary recommendations made based upon reviews were to: (1) consider balancing usage (cost) and gain (benefit), rather than impacts; (2) consider indirect (cascading/consequential) interactions. Overall, existing measures of sustainability and sustainable development practices in WDSs must be advanced to accommodate a focus on restorative systems, as well as to maximize benefits and enable multidisciplinary and broader analyses.

Calories delivered by nonhuman primate foraging enrichment: Data and methods to inform decisions concerning the dietary consequences of enrichment

Foraging opportunities are a key component of enrichment in captive nonhuman primates providing manipulative opportunities in which animals can engage in species-typical behaviors. Recent studies suggest captive NHP populations have increased body weight over time leading to negative health outcomes. Increasing food foraging opportunities provides added calories that can be estimated but often are not directly measured. We assessed 10 commonly used foraging puzzles for the amount of foraging material they held; evaluated the range of caloric content delivered; and determine the labor and usage cost of each. Five preparation areas were sampled. The amount of foraging material contained in each prepared puzzle was calculated by subtracting the average empty puzzle weight from the loaded puzzle weight. A detailed description of food content was used to illustrate caloric content. Larger prepared puzzles held more food (M=104.9 g) as compared to small volumes puzzles (M=59.8 g). Analysis of the weight of food applied and caloric content suggest larger puzzles do have the potential to provide increased caloric load; however, the added food from large foraging puzzles constitutes only 5%-10% of the daily k/cal dietary requirement. The study illustrates the importance of considering puzzle characteristics when selecting foraging toys and discusses the considerations of cost of puzzle deployment, maintenance and interactive benefit. The broad significance of our assessment suggests that calories from foraging opportunities are not excessive and can be managed by adopting standard serving sizes and scheduling intermitted presentation of non-nutritive enrichment options.

To buy or to borrow? Evaluating the cost of an eBook in TalTech library

Purpose The purpose of this paper is to find out how much the purchasing and lending of individual electronic books really cost. Additionally, this paper investigates which kind of approach would be cheaper and less time-consuming for library staff as well as library patrons – purchase or short-term loan. Design/methodology/approach This study was conducted at the Tallinn University of Technology (TalTech) Library. This is the only university library in Estonia where the Ebook Central platform is adapted on a large scale. For background information, all statistical data of expenditures and average prices of purchases and short-term loans during April 2013 and December 2018 were calculated and analysed. Through a case study, the time-driven activity-based costing (TDABC) method was used – all activities related to acquisition and lending of eBooks were identified, recorded in detail and analysed. More specifically, the study concerned eBooks offered in the Ebook Central platform and covered purchasing and short-term loan processes, such as receipt of order request, communication with the patron (if necessary) making a purchase or short-term loan, and feedback to the patron. Findings While analysing the results, it appeared there are many additional activities libraries can avoid during the eBook short-term loan process compared to purchasing. As a normality in TalTech library, purchase is always followed by a cataloguing process which increases the time and cost of this process in turn. On the basis of the current study, it can be said that short-term loan is a cheaper way to use eBooks; many activities related to the short-term loan of eBooks take remarkably less staff time and financial resources than eBooks acquisition/purchasing activities. When analysing the literature reviewed as well as collected statistical data, the problem may arise when the decision-maker librarian is not experienced, professional or long-sighted enough to understand the future behaviour of the patron or the usage of the specific eBook. When the usage reaches a certain point, it becomes an indicator of continuing future usage and so it makes sense to purchase the eBook, as the library pays no further charges once an eBook is owned. Originality/value Most studies reviewed by the author are based on the statistical data collected about expenditure, costs, usage, cost-per-use, etc. of short-term loans and purchases. While acquisitions costs, average cost per acquired item per year and cost per usage are easy to identify, it has been difficult to measure associated costs of acquisition, cataloging and circulation. The TDABC methodology seems to be one of the best tools for understanding cost behaviour and refining a cost system for university libraries. Based on the information known to the author, there is no study carried out using the TDABC methodology for analysing costs of eBook programmes.