scholarly journals Multi-response optimization of the stabilization/solidification process of industrial hazardous waste

2020 ◽  
Vol 9 (4) ◽  
pp. e144942997
Author(s):  
Sayeny de Avila Gonçalves ◽  
Rafaela Cristina Sanfelice ◽  
Kassia Graciele dos Santos
Keyword(s):  
Waste Treatment ◽  
Clayey Soil ◽  
Low Cost ◽  
Liquid Waste ◽  
Minimum Cost ◽  
Solidification Process ◽  
Cellulose Pulp ◽  
Response Optimization ◽  
The Cost ◽  
Central Composite

Solidification/Stabilization (S/S) is an important technique used in waste treatment, due its low cost and easily processing. The aim of this study was to optimize and standardize the S/S process in a Brazilian company. The packing of the dangerous residue was done using a mixture of different solidifying agents, such as: clayey soil; superabsorbent polymer (SAP)/cellulose pulp (fluff) and sanding powder. It was evaluated the effect of different amount of solidifying agent over the volume of packed mixture, the final moisture and the cost of the S/S process, using a Central Composite Design.  The results showed a minimum cost for the S/S operation of R$ 192.89/ton of liquid waste, using about 71.69 tons of clay soil for each ton of untreated residue, allowing a highly packed residue with a moisture up to 20% (w.b.).

Optimization of the Design of Hydrogen Production Systems Based on Product Cost

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Abdelhamid Mraoui ◽  
Abdallah Khellaf
Keyword(s):  
Hydrogen Production ◽  
Production Systems ◽  
Low Cost ◽  
Minimum Cost ◽  
Total Power ◽  
Photovoltaic Module ◽  
Power Ratio ◽  
The Cost ◽  
Pv Generator ◽  
Practical Constraints

Abstract In this work, the design of a hydrogen production system was optimized for Algiers in Algeria. The system produces hydrogen by electrolysis using a photovoltaic (PV) generator as a source of electricity. All the elements of the system have been modeled to take into account practical constraints. The cost of producing hydrogen has been minimized by varying the total power of the photovoltaic generator. An optimal ratio between the peak power of the PV array and the nominal power of the electrolyzer was determined. Photovoltaic module technology has been varied using a large database of electrical characteristics. It was noted that PV technology does not have a very significant impact on cost. The minimum cost is around 0.44$/N m3, and the power ratio in this case is 1.45. This results in a cost reduction of around 12% compared to a unit ratio. The power ratio and cost are linearly dependent. Only a small number of technologies give a relatively low cost of about 0.35$/N m3. These generators are interesting; however, we assumed an initial cost of $2.00/Wp for all technologies. In addition, it was noted that it is possible to increase hydrogen production by 10% by increasing the power of the photovoltaic generator, the extra cost in this case will only be 0.1%.

scholarly journals Energetics of Hermit Crabs during Locomotion: The Cost of Carrying a Shell

1986 ◽  
Vol 120 (1) ◽  
pp. 297-308 ◽  
Author(s):  
CLYDE F. HERREID ◽  
ROBERT J. FULL
Keyword(s):  
Fuel Economy ◽  
Low Cost ◽  
Minimum Cost ◽  
Hermit Crabs ◽  
Absolute Difference ◽  
Cost Of Transport ◽  
The Difference ◽  
The Cost ◽  
Response To Exercise ◽  
Leg Position

Oxygen consumption (VOO2) was measured as hermit crabs (Coenobita compressus) walked at controlled velocities on a motor-driven treadmill inside a small respirometer. The crabs displayed an aerobic response to exercise with a rapid increase in VOO2 reaching a steady state in about 5–6 min followed by a rapid recovery. The highest VOO2 was four times the resting rate. VOO2 was directly dependent on the velocity of travel (V): VOO2 = 0.29+1.98V. Metabolic rate was increased significantly in crabs with bilateral leg ablation. The cost of shell carrying was evaluated by comparing VOO2 of crabs with and without their protective snail shells at different velocities; the absolute difference was constant (0.17 ml O2g−1 h−1), suggesting that the cost of shell support was constant per unit of time regardless of speed. The cost of transport dropped dramatically with speed for crabs both with and without snail shells. Crabs carrying shells used twice as much O2 per gram per kilometre as did ‘nude’ crabs walking slowly at 0.02 kmh−1 but the difference decreased to 1.3 times when velocity was increased 10-fold. Hermit crabs did not increase their VOO2 proportionately with load: the VOO2 loaded/unloaded ratio was consistently less than the mass loaded/unloaded ratio. This apparent increase in efficiency may be due to the fact that crabs carrying heavy shells alter their leg position and tend to drag their shell. Crabs with and without shells have the same minimum cost of transport CM, so travel at the highest velocity is theoretically the most economical way to cover a given distance. Appropriately, crabs on the beach average a fast 0.23 km h−1 which produces a low cost of transport only 1.3 times higher than CM. The CM of six-legged hermit crabs is comparable to that of mammals, birds, crabs and insects of similar size and indicates that leg number does not affect fuel economy.

scholarly journals A critical review on various feedstocks as sustainable substrates for biosurfactants production: a way towards cleaner production

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Swayansu Sabyasachi Mohanty ◽  
Yamini Koul ◽  
Sunita Varjani ◽  
Ashok Pandey ◽  
Huu Hao Ngo ◽  
...  
Keyword(s):  
Waste Management ◽  
Critical Review ◽  
Waste Treatment ◽  
State Of The Art ◽  
Low Cost ◽  
Cleaner Production ◽  
Biosurfactant Production ◽  
Waste Materials ◽  
Manufacturing Costs ◽  
The Cost

AbstractThe quest for a chemical surfactant substitute has been fuelled by increased environmental awareness. The benefits that biosurfactants present like biodegradability, and biocompatibility over their chemical and synthetic counterparts has contributed immensely to their popularity and use in various industries such as petrochemicals, mining, metallurgy, agrochemicals, fertilizers, beverages, cosmetics, etc. With the growing demand for biosurfactants, researchers are looking for low-cost waste materials to use them as substrates, which will lower the manufacturing costs while providing waste management services as an add-on benefit. The use of low-cost substrates will significantly reduce the cost of producing biosurfactants. This paper discusses the use of various feedstocks in the production of biosurfactants, which not only reduces the cost of waste treatment but also provides an opportunity to profit from the sale of the biosurfactant. Furthermore, it includes state-of-the-art information about employing municipal solid waste as a sustainable feedstock for biosurfactant production, which has not been simultaneously covered in many published literatures on biosurfactant production from different feedstocks. It also addresses the myriad of other issues associated with the processing of biosurfactants, as well as the methods used to address these issues and perspectives, which will move society towards cleaner production.

scholarly journals A Study of the Adsorption Characteristics of Cobalt and Caesium from a Solution by Using Vietnamese Bentonite

2015 ◽  
Vol 43 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Le Phuoc Cuong ◽  
Pham Hoang Giang ◽  
Bui Dang Hanh ◽  
Gergő Bátor
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Radioactive Waste ◽  
Nuclear Power ◽  
Large Scale ◽  
High Efficiency ◽  
Waste Treatment ◽  
Low Cost ◽  
Liquid Waste ◽  
Controversial Topic

Abstract The radioactive waste produced from the construction of a nuclear power plant is a controversial topic. The resulting radioactive waste contains 60Co and 137Cs isotopes that are the most difficult to remove. Bentonite is widely used as an adsorbent for heavy metals. An important factor is the safe operation of waste management at a nuclear power plant to be built in Vietnam. Therefore, a method of degrading complexes of radionuclides and the adsorption of radionuclides onto Vietnamese Bentonite was implemented in this study. In current literature, UV radiation and heating with oxidising substances are used in general for degrading complexes of radionuclides. The experimental results for the adsorption of Co(II) and Cs+ onto VNB suggest that VNB can be used in the future for large-scale liquid waste treatment due to its low cost, high efficiency, and environmentally friendliness.

scholarly journals Novel Low-Cost Biosorbents of Phenolic Compounds from Olive Mill Wastewaters

Proceedings ◽  
2020 ◽  
Vol 67 (1) ◽  
pp. 1
Author(s):  
Nikoletta Solomakou ◽  
Athanasia M. Goula
Keyword(s):  
Phenolic Compounds ◽  
Olive Oil ◽  
Waste Treatment ◽  
Low Cost ◽  
Liquid Waste ◽  
Raw Material ◽  
Adsorptive Capacity ◽  
Regeneration System ◽  
High Concentration ◽  
Olive Mill

Olive oil is one of the most widely used oils in the world with economic importance for many countries. Olive oil extraction generates large amounts of solid (cake) and liquid waste (olive mill wastewater, OMW), which pose a chronic environmental problem due to their disposal of the produced wastes on the landfill and water recipients. Thus, the research community is in search of techniques, individually or in combination, in order to detoxify waste. The common treatment methods belong to a one-dimensional waste treatment approach, which is depollution. A practical way to overcome the financial obstacle of depollution is to develop treatment schemes that combine depollution with recovery of valuable ingredients, such as phenolics. The toxicity of this waste is mainly due to the high concentration of phenolic compounds, which, however, have strong antioxidant activity, turning OMW into an economical raw material for the recovery of bioactive compounds. Adsorption is generally considered to be the most effective and low-cost method for the removal of phenolics. So far, few studies have been carried out using sorbents for the removal of phenolics from OMW. However, the relatively high initial cost and the need for a costly regeneration system render common sorbents less economically viable. Thus, many researchers have focused their efforts on optimizing adsorption process by development of novel, low-cost adsorbents with high adsorptive capacity, originating from food industry byproducts (biosorbents). The objective of this work is to provide a comprehensive summary of the biosorbents used for OMW management.

scholarly journals Heuristic Methods for Minimum-Cost Pipeline Network Design – a Node Valency Transfer Metaheuristic

2021 ◽  
Author(s):  
Christopher Yeates ◽  
Cornelia Schmidt-Hattenberger ◽  
Wolfgang Weinzierl ◽  
David Bruhn
Keyword(s):  
Network Design ◽  
Large Scale ◽  
Low Cost ◽  
Minimum Cost ◽  
Local Flow ◽  
Complexity Of Algorithms ◽  
Pipeline Networks ◽  
Optimization Heuristics ◽  
Novel Algorithms ◽  
The Cost

AbstractDesigning low-cost network layouts is an essential step in planning linked infrastructure. For the case of capacitated trees, such as oil or gas pipeline networks, the cost is usually a function of both pipeline diameter (i.e. ability to carry flow or transferred capacity) and pipeline length. Even for the case of incompressible, steady flow, minimizing cost becomes particularly difficult as network topology itself dictates local flow material balances, rendering the optimization space non-linear. The combinatorial nature of potential trees requires the use of graph optimization heuristics to achieve good solutions in reasonable time. In this work we perform a comparison of known literature network optimization heuristics and metaheuristics for finding minimum-cost capacitated trees without Steiner nodes, and propose novel algorithms, including a metaheuristic based on transferring edges of high valency nodes. Our metaheuristic achieves performance above similar algorithms studied, especially for larger graphs, usually producing a significantly higher proportion of optimal solutions, while remaining in line with time-complexity of algorithms found in the literature. Data points for graph node positions and capacities are first randomly generated, and secondly obtained from the German emissions trading CO2 source registry. As political will for applications and storage for hard-to-abate industry CO2 emissions is growing, efficient network design methods become relevant for new large-scale CO2 pipeline networks.

A generalized fuzzy cost efficiency model

2020 ◽  
Vol 54 (6) ◽  
pp. 1775-1791
Author(s):  
Nazila Aghayi ◽  
Samira Salehpour
Keyword(s):  
Cost Efficiency ◽  
Minimum Cost ◽  
Extensive Literature ◽  
Data Envelopment ◽  
Fuzzy Environment ◽  
Decision Making Unit ◽  
Production Possibility Set ◽  
Fuzzy Cost ◽  
The Cost ◽  
Generalized Cost

The concept of cost efficiency has become tremendously popular in data envelopment analysis (DEA) as it serves to assess a decision-making unit (DMU) in terms of producing minimum-cost outputs. A large variety of precise and imprecise models have been put forward to measure cost efficiency for the DMUs which have a role in constructing the production possibility set; yet, there’s not an extensive literature on the cost efficiency (CE) measurement for sample DMUs (SDMUs). In an effort to remedy the shortcomings of current models, herein is introduced a generalized cost efficiency model that is capable of operating in a fuzzy environment-involving different types of fuzzy numbers-while preserving the Farrell’s decomposition of cost efficiency. Moreover, to the best of our knowledge, the present paper is the first to measure cost efficiency by using vectors. Ultimately, a useful example is provided to confirm the applicability of the proposed methods.

Advance Protection for Three Phase Induction Motor using Microcontroller Atmega32

2018 ◽  
Vol 8 (1) ◽  
pp. 172
Author(s):  
Karan S Belsare ◽  
Gajanan D Patil
Keyword(s):  
Induction Motor ◽  
Low Cost ◽  
Short Circuit ◽  
Cost Factor ◽  
Protection Scheme ◽  
Three Phase ◽  
The Cost

A low cost and reliable protection scheme has been designed for a three phase induction motor against unbalance voltages, under voltage, over voltage, short circuit and overheating protection. Taking the cost factor into consideration the design has been proposed using microcontroller Atmega32, MOSFETs, relays, small CTs and PTs. However the sensitivity of the protection scheme has been not compromised. The design has been tested online in the laboratory for small motors and the same can be implemented for larger motors by replacing the i-v converters and relays of suitable ratings.

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

Main approaches to estimating the cost of shareholder equity of oil and gas producers

2020 ◽  
Vol 26 (3) ◽  
pp. 685-697
Author(s):  
O.V. Shimko
Keyword(s):  
Oil And Gas ◽  
Oil Prices ◽  
Minimum Cost ◽  
Free Cash Flow ◽  
Annual Reports ◽  
Comparative Approach ◽  
Economic Activities ◽  
Advantages And Disadvantages ◽  
Oil And Gas Producers ◽  
The Cost

Subject. The study analyzes generally accepted approaches to assessing the value of companies on the basis of financial statement data of ExxonMobil, Chevron, ConocoPhillips, Occidental Petroleum, Devon Energy, Anadarko Petroleum, EOG Resources, Apache, Marathon Oil, Imperial Oil, Suncor Energy, Husky Energy, Canadian Natural Resources, Royal Dutch Shell, Gazprom, Rosneft, LUKOIL, and others, for 1999—2018. Objectives. The aim is to determine the specifics of using the methods of cost, DFC, and comparative approaches to assessing the value of share capital of oil and gas companies. Methods. The study employs methods of statistical analysis and generalization of materials of scientific articles and official annual reports on the results of financial and economic activities of the largest public oil and gas corporations. Results. Based on the results of a comprehensive analysis, I identified advantages and disadvantages of standard approaches to assessing the value of oil and gas producers. Conclusions. The paper describes pros and cons of the said approaches. For instance, the cost approach is acceptable for assessing the minimum cost of small companies in the industry. The DFC-based approach complicates the reliability of medium-term forecasts for oil prices due to fluctuations in oil prices inherent in the industry, on which the net profit and free cash flow of companies depend to a large extent. The comparative approach enables to quickly determine the range of possible value of the corporation based on transactions data and current market situation.

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