Addition of anaerobic ammonium oxidation bacteria to lower running cost during the membrane bioreactor process treating sewage

Reducing energy consumption or running cost associated with the membrane bioreactor (MBR) process is a serious challenge that needs to be addressed in treating sewage. The addition of anaerobic ammonium oxidation bacteria (AnAOB) to a running MBR has the potential to lower the aeration rate, thus decreasing the running cost in treating sewage. The results obtained showed that owing to addition of AnAOB, TN and NH4+-N removal rates increased by 9.8% and 1.13%, respectively, while the aeration rate decreased by 50%. Additionally, high throughput sequencing and isotope experiments showed that both AnAOB and heterotrophic denitrification bacteria could survive simultaneously and play an important role in nitrogen removal, with AnAOB having a significantly greater contribution. It can be concluded that the addition of AnAOB reduced the running cost of MBR in treating sewage.

Economics-Based Payback and Life Cycle Cost Savings Assessment of Inverter Type Air Conditioners

This paper investigates the options for a consumer to choose between different inverter and non-inverter type residential air conditioners (ACs) concerning their payback periods (PPs) and Life Cycle Cost (LCC) savings. The economics-based analysis carried out to evaluate the PPs by which the costs associated with owning and operating 3-star, 4-star, and 5-star inverter AC models are recoverable compared to non-inverter type (baseline model). The product costs (Cp ), the repair costs (CR ), the maintenance costs (CM ), and the energy costs (CE ) are taken as the decision parameters for evaluating the payback periods (PPs). It is shown that PP strongly depends on the energy cost. Estimates of P P s are calculated as the futurs value of present cost involved in buying, maintaining, and running the ACs. It is concluded that inverter technology can save electrical energy by 12-22.4% compared to a non-inverter air conditioner. PP of 3-star inverter AC is estimated 2.17 years while P P of 4-star and 5-star inverter ACs are 2.42 years and 2.33 years for 10 hours operation in a day when a higher slab of unit energy cost is considered. Depending on PP and daily usage requirements, a consumer can choose either a less efficient AC priced at a lower initial cost but more running cost or a more efficient AC priced at a higher initial cost but lesser running cost.

Minimizing the Cost of PHEV Usage with Price Sensitive Charging Strategies

Electric cars sales have been rising almost steadily over the past decade. Uncontrolled charging has recently emerged as the main detrimental factor to this otherwise environmentally friendly and paradigm shifting technology due to the incurred impact on the energy grid. In addition, people are usually hesitant in allowing their vehicles to be controlled by external units; therefore, controlled charging strategies that offer users the option to have some control over their vehicles seems to be a sensible choice moving towards a gasoline-free vehicles market. This work investigated two price-sensitive charging strategies that allowed users to control the charging of their vehicle in order to receive cost benefits. These strategies were of a parametric nature; thus, the analysis focused on providing useful rules of thumb to guide users in choosing the most suitable strategy and the relevant parameters according to their driving profiles. The results show that when driving less than 40 km/h on average and employing a price-sensitive charging strategy with the proposed optimized parameters, electric car users may obtain 30–40% of the running cost reduction.

Domestic Retrofit Assessment of the Heat Pump System Considering the Impact of Heat Supply Temperature and Operating Mode of Control—A Case Study

In this study, performance assessment of the variable speed compressor-based air source heat pump (ASHP) system as a domestic retrofit technology instead of fossil fuel-based heating technologies for the 1900s Mid terraced house is investigated. The assessment was conducted considering operating mode of control and heat supply temperature impact of the system. In the literature, ASHP system experimental development with variable speed mode (VSM) of control in comparison to fixed speed mode (FSM) of control at low to medium and high heat supply temperature in the context of UK was found with very limited number of studies, but without considering retrofit application. The focus of the earlier studies was on the individual components and performance improvement. The designed heat pump (HP), developed, and tested at constant heat load, simulating the real domestic heat demand under the controlled laboratory conditions and numerical modeling is utilized for the analysis purposes. The HP performance, energy demand, carbon emissions, and cost varies significantly due to changing heat supply temperature (35 °C, 45 °C, and 55 °C), control mode and accordingly the carbon emission and cost savings are achieved. The oil and gas boilers ranges from conventional to highly efficient type and evaluated in terms of annual running cost, energy consumptions, and carbon emissions in comparison with the HP system. Additionally, a comparative study with the existing retrofitted very high temperature ASHP inside the house is conducted. The developed HP at 55 °C could not defeat the very high heat supply temperature HP system (75 °C supply temperature) in performance and cost savings but become attractive at low supply temperature (35 °C). The HP system in VSM at low heat supply temperature instead of gas boiler (90% efficiency) could cut the annual carbon emissions by 59% but with additional 6% running cost for the Mid terraced test house in Belfast climatic conditions.

Design and Path Planning of Autonomous Solar Lawn Mower

Current conventional lawn mowers have the following drawbacks; high initial costs, increasing engine noise levels, high operating costs due to high fuel consumption rates, the need to implement perimeter wires across the desired lawn mowing field, and high exhaustion of the operator in the long operating time. Hence, the need for a system that can achieve the same cutting effect of the existing lawn mowers with little or no operator’s fatigue, minimized noise pollution and running cost has risen. In present work, design of an autonomous solar lawn mower, a robotic vehicle that cut grass automatically with little human intervention, is discussed. The robotic vehicle is powered by Lithium-Ion batteries and depend on solar power delivered from a solar base station for charging the batteries. The mechanical design of the vehicle is flexible with the ability to control the height of the vehicle during grass mowing. Differential steering, with the implementation of multiple sensors is presented for obstacle avoidance. Also, a Raspberry Pi microcontroller for the image processing application through a camera is used for path planning. Furthermore, a solar based station structure is designed for charging the robotic vehicle batteries with minimized running cost, utilization of renewable energy source, no health hazards, not having any effect on the environment, and human’s effort and time are saved.

CHALLENGES AND OPPORTUNITIES LINKED WITH WASTE MANAGEMENT UNDER GLOBAL PERSPECTIVE: A MINI REVIEW

In today’s world, Waste production and its handling has become a great challenge. Rapid urbanization and conversion of rural land into housing societies creates bulk of waste withing a short span in any area. Whileincreasing population, increase in waste is a topic of discussion in developed as well as developing countries and it may become the biggest problem in the near futurefor the world. It is emphasized that only municipal solid waste will be 3.40 billion tons by 2050. Different types of waste are produced and it’shandling also requires different techniques. Now a day, different techniques are used to overcome this problem. These techniques reduce the waste by weight and severity of its effect, but they also release end product that maybeharmful for the environment. This review will discuss the techniques like landfills, incineration, composting, recovering, combustion, energy production, plasma gasification etc. Different techniques have different merits and demerits.However, every technique required specific input running cost and it may be variedfrom area to area and country to country due to economic crises in developing countries. This review covers thetypes of waste, waste management opportunities, and challenges as well as the benefits of waste management techniques

Computation of Reachable Sets Based on Hamilton-Jacobi-Bellman Equation with Running Cost Function

A novel method for computing reachable sets is proposed in this paper. In the proposed method, a Hamilton-Jacobi-Bellman equation with running cost function is numerically solved and the reachable sets of different time horizons are characterized by a family of non-zero level sets of the solution of the Hamilton-Jacobi-Bellman equation. In addition to the classical reachable set, by setting different running cost functions and terminal conditions of the Hamilton-Jacobi-Bellman equation, the proposed method allows to compute more generalized reachable sets, which are referred to as cost-limited reachable sets. In order to overcome the difficulty of solving the Hamilton-Jacobi-Bellman equation caused by the discontinuity of the solution, a method based on recursion and grid interpolation is employed. At the end of this paper, some examples are taken to illustrate the validity and generality of the proposed method.

Computation of Reachable Sets Based on Hamilton-Jacobi-Bellman Equation with Running Cost Function

A novel method for computing reachable sets is proposed in this paper. In the proposed method, a Hamilton-Jacobi-Bellman equation with running cost function is numerically solved and the reachable sets of different time horizons are characterized by a family of non-zero level sets of the solution of the Hamilton-Jacobi-Bellman equation. In addition to the classical reachable set, by setting different running cost functions and terminal conditions of the Hamilton-Jacobi-Bellman equation, the proposed method allows to compute more generalized reachable sets, which are referred to as cost-limited reachable sets. In order to overcome the difficulty of solving the Hamilton-Jacobi-Bellman equation caused by the discontinuity of the solution, a method based on recursion and grid interpolation is employed. At the end of this paper, some examples are taken to illustrate the validity and generality of the proposed method.

Outdoor Uphill Exercise Testing for Trail Runners, a More Suitable Method?

There is extensive knowledge about uphill running on a treadmill, although paucity regarding the influence of uphill trail running on exercise capacity in runners. The purpose of this study was to compare an uphill field test with a treadmill test with 1% inclination especially considering cardiopulmonary exercise variables. The difference in those tests between a group of trail runners and a group of road runners was tested for establishing a test specifically for trail runners. Ten male endurance road runners and ten male trail runners performed one maximal incremental treadmill test with 1% inclination and a maximal incremental field test on a hill at 16% inclination which they were instructed to run up four times for three minutes, each time with a higher pace. A mobile cardiopulmonary exercise testing unit was used to measure ventilation. There were no significant differences between trail runners and road runners. The equivalence factor was comparable between both groups. V ˙ O 2 p e a k $\dot{V} O_{2 p e a k}$ was comparable for both test protocols. However, there was a significant difference between the two test protocols regarding lactate concentration, the respiratory exchange ratio, running cost, heart rate, Breathing reserve, and O2pulse. The greater lactate concentration and running cost recorded uphill indicate a higher energy demand during trail running than level road running.