Grinding Kinetics Study of Tungsten Ore

The European Commission (EC) maintains the consideration of tungsten as a critical raw material for the European industry, being the comminution stage of tungsten-bearing minerals an essential step in the tungsten concentration process. Comminution operations involve approximately 3–4% of worldwide energy consumption; therefore, grinding optimization should be a priority. In this study, the grinding behavior of tungsten ore from Barruecopardo Mine (Salamanca, Spain) is analyzed. A protocol based on Austin’s methodology and PBM is developed in order to study the influence of operational and geometallurgical variables on grinding kinetics. In addition to the kinetic parameters, the breakage probability (Si) and breakage function (Bij) is determined. The selection function was formulated for the Barruecopardo Mine with respect to the mill speed.

Download Full-text

Life-Cycle Assessment of Carbon Footprint of Bike-Share and Bus Systems in Campus Transit

Sustainability ◽

10.3390/su13010158 ◽

2020 ◽

Vol 13 (1) ◽

pp. 158

Author(s):

Sishen Wang ◽

Hao Wang ◽

Pengyu Xie ◽

Xiaodan Chen

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Energy Consumption ◽

Carbon Footprint ◽

Co2 Emission ◽

Raw Material ◽

Transit System ◽

Two Systems ◽

Bus System ◽

Bike Share

Low-carbon transport system is desired for sustainable cities. The study aims to compare carbon footprint of two transportation modes in campus transit, bus and bike-share systems, using life-cycle assessment (LCA). A case study was conducted for the four-campus (College Ave, Cook/Douglass, Busch, Livingston) transit system at Rutgers University (New Brunswick, NJ). The life-cycle of two systems were disaggregated into four stages, namely, raw material acquisition and manufacture, transportation, operation and maintenance, and end-of-life. Three uncertain factors—fossil fuel type, number of bikes provided, and bus ridership—were set as variables for sensitivity analysis. Normalization method was used in two impact categories to analyze and compare environmental impacts. The results show that the majority of CO2 emission and energy consumption comes from the raw material stage (extraction and upstream production) of the bike-share system and the operation stage of the campus bus system. The CO2 emission and energy consumption of the current campus bus system are 46 and 13 times of that of the proposed bike-share system, respectively. Three uncertain factors can influence the results: (1) biodiesel can significantly reduce CO2 emission and energy consumption of the current campus bus system; (2) the increased number of bikes increases CO2 emission of the bike-share system; (3) the increase of bus ridership may result in similar impact between two systems. Finally, an alternative hybrid transit system is proposed that uses campus buses to connect four campuses and creates a bike-share system to satisfy travel demands within each campus. The hybrid system reaches the most environmentally friendly state when 70% passenger-miles provided by campus bus and 30% by bike-share system. Further research is needed to consider the uncertainty of biking behavior and travel choice in LCA. Applicable recommendations include increasing ridership of campus buses and building a bike-share in campus to support the current campus bus system. Other strategies such as increasing parking fees and improving biking environment can also be implemented to reduce automobile usage and encourage biking behavior.

Download Full-text

Crushed Bricks: Demolition Waste as a Sustainable Raw Material for Geopolymers

Sustainability ◽

10.3390/su13147572 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7572

Author(s):

Gigliola D’Angelo ◽

Marina Fumo ◽

Mercedes del Rio Merino ◽

Ilaria Capasso ◽

Assunta Campanile ◽

...

Keyword(s):

Energy Consumption ◽

Building Materials ◽

Mechanical Performance ◽

Raw Materials ◽

Construction Material ◽

Raw Material ◽

The European Union ◽

Total Energy Consumption ◽

Demolition Waste ◽

Crushed Brick

Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of open porosity, water absorption, mechanical strength, and surface resistance values when compared to building materials produced using traditional technologies.

Download Full-text

The Influencing Factors Analysis of Implementing Green Supply Chain Based on the Investigation Data in Shandong Province of China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.671-674.3049 ◽

2013 ◽

Vol 671-674 ◽

pp. 3049-3054

Author(s):

Cao Qian ◽

Xi Jian Quan ◽

Yu Yan Wang

Keyword(s):

Factor Analysis ◽

Supply Chain ◽

Energy Consumption ◽

Product Design ◽

Influencing Factors ◽

Shandong Province ◽

Raw Material ◽

Green Supply Chain ◽

Manufacturing Enterprises ◽

Factors Analysis

On the basis of investigation and research, we firstly determined factors that impact manufacturing enterprises to implement green supply chain. Then, based on data of Parts of manufacturing enterprises in Shandong Province implementing green supply chain, the influencing factors of manufacturing enterprises implementing green supply chain is analyzed by factor analysis. The conclusion show that the influencing factors mainly concentrates in seven aspects that is raw material purchase, the enterprise internal management, the worn recycling, the product design, the enterprise prestige, the enterprise energy consumption, the reject processes.

Download Full-text

Improving Duty Cycle-based MAC Protocol in Wireless Networks using AI and Machine Learning

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.b4083.129219 ◽

2019 ◽

Vol 9 (2) ◽

pp. 3011-3017

Keyword(s):

Machine Learning ◽

Energy Consumption ◽

Duty Cycle ◽

Mac Protocol ◽

Selection Function ◽

Medium Access ◽

Sleep Phase ◽

Agricultural Applications ◽

Time Division ◽

Wireless Node

Duty cycle of a Medium Access Control (MAC) protocol is made up of sleep phase, wake-up phase and listen phase. MAC protocols usually proposes to optimize the duration of the wake-up and listen phases, in order to increase the duration of the sleep phase, thereby reducing the unwanted energy consumption of the wireless node. In this paper, we propose an Artificial Intelligence (AI) and machine learning (ML) based approach, which uses a hybrid combination of Time Division Multiple Access (TDMA), Bitmap Assisted MAC (BMA) and Sensor MAC (SMAC). The machine learning layer utilizes the duty cycle in the MAC layer, and generates multiple solutions for a given wireless communication. The AI layer then selects the best solution from the generated solutions by incorporating a duty cycle factor in the selection function, thereby optimizing the duty cycle of the protocol. The proposed system shows a 15% improvement in communication speed, and a 10% reduction in energy consumption across multiple communications. We plan to further extend this work for rural India, and apply it to real time agricultural applications.

Download Full-text

Processes of heat and mass transfer during drying of red beetroot

Energy Engineering and Control Systems ◽

10.23939/jeecs2020.02.081 ◽

2020 ◽

Vol 6 (2) ◽

pp. 81-87

Author(s):

Zhanna Petrova ◽

◽

Kateryna Samoilenko ◽

Vitaly Vishnevsky

Keyword(s):

Mass Transfer ◽

Energy Consumption ◽

Heat And Mass Transfer ◽

Raw Materials ◽

Antioxidant Properties ◽

Calculation Model ◽

Experimental Results ◽

Biologically Active ◽

Raw Material ◽

Drying Process

Red beetroot is the main raw material which has a high content of betanine with antioxidant properties. An important emphasis in the processing of antioxidant raw materials by drying is to reduce energy consumption for the dehydration process, the maximum preservation of biologically active substances, and to reduce the cost of the final product. Drying is a complex and energy-intensive process. Therefore, to optimize energy consumption during drying and selection of rational modes of dehydration, it is necessary to apply the calculated analysis of heat and mass transfer on the basis of adequate mathematical models. Calculated and experimental results are compared. In general, the comparison of the results of numerical modeling of convection drying processes of the red beetroot sample with the experimental results showed their rather satisfactory qualitative agreement. The calculation model can be used to approximate the characteristics of the drying process of red beetroot, in particular the time required for drying. The obtained results of calorimetric studies allow stating that with correctly selected compositions, not only the components of native raw materials are stabilized, but also the drying process is intensified with the reduction of energy consumption to process.

Download Full-text

Energy Consumption, Trade and GDP: A Case Study of South Asian Countries

The Pakistan Development Review ◽

10.30541/v53i4iipp.461-476 ◽

2014 ◽

Vol 53 (4II) ◽

pp. 461-476 ◽

Cited By ~ 7

Author(s):

Muhammad Shakeel ◽

M. Mazhar Iqbal ◽

M.. Tariq Majeed

Keyword(s):

Energy Consumption ◽

Production Process ◽

South Asian ◽

Electrical Equipment ◽

International Markets ◽

Raw Material ◽

Asian Countries ◽

Multiplier Effect ◽

Reasonable Cost

Acute shortage of energy sources in developing countries in general and South Asian countries in particular has shown that energy has become a binding input for any production process. Nowadays operation of heavy machinery and electrical equipment, and transportation of raw material and final products from their place of origination to their destination require heavy consumption of energy in one form or the other. Therefore, energy consumption that was previously ignored in the production function of a firm and an economy is now considered a vital input in production process. It affects GDP directly as by increasing energy consumption; more output can be produced with given stock of capital and labor force in a country. Also uninterrupted availability of energy at reasonable cost improves competiveness of home products in international markets and thus increases exports of home country a great deal. Resulting increase in net exports further adds to the GDP through multiplier effect

Download Full-text

Pelletization of Sunflower Seed Husks: Evaluating and Optimizing Energy Consumption and Physical Properties by Response Surface Methodology (RSM)

Processes ◽

10.3390/pr7090591 ◽

2019 ◽

Vol 7 (9) ◽

pp. 591 ◽

Cited By ~ 3

Author(s):

Xuyang Cui ◽

Junhong Yang ◽

Xinyu Shi ◽

Wanning Lei ◽

Tao Huang ◽

...

Keyword(s):

Response Surface Methodology ◽

Energy Consumption ◽

Moisture Content ◽

Physical Properties ◽

Response Surface ◽

Sunflower Seed ◽

Biomass Energy ◽

Raw Material ◽

The Novel ◽

Seed Husk

Pelletization is a significant approach for the efficient utilization of biomass energy. Sunflower seed husk is a common solid waste in the process of oil production. The novelty of this study was to determine the parameters during production of a novel pellet made from sunflower seed husk. The energy consumption (W) and physical properties (bulk density (BD) and mechanical durability (DU)) of the novel pellet were evaluated and optimized at the laboratory by using a pelletizer and response surface methodology (RSM) under a controlled moisture content (4%–14%), compression pressure (100–200 MPa), and die temperature (70–170 °C). The results show that the variables of temperature, pressure, and moisture content of raw material are positively correlated with BD and DU. Increasing the temperature and moisture content of raw materials can effectively reduce W, while increasing the pressure has an adverse effect on W. The optimum conditions of temperature (150 °C), pressure (180 MPa), and moisture content (12%) led to a BD of 1117.44 kg/m3, DU of 98.8%, and W of 25.3 kJ/kg in the lab. Overall, although the nitrogen content was slightly high, the novel manufactured pellets had excellent performance based on ISO 17225 (International Organization for Standardization of 17225, Geneva, Switzerland, 2016). Thus, sunflower seed husk could be considered as a potential feedstock for biomass pelletization.

Download Full-text

A Study on Energy Consumption and CO2 Emissions According to Manufacture of Recycled Rebar Using Wasted Steel from Building Demolition

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.357-360.869 ◽

2013 ◽

Vol 357-360 ◽

pp. 869-875

Author(s):

Gi Wook Cha ◽

Won Hwa Hong ◽

Sung Woo Shin

Keyword(s):

Energy Consumption ◽

Iron Ore ◽

Ghg Emissions ◽

Raw Material ◽

Input Output ◽

Output Analysis ◽

Input Output Analysis ◽

Ghg Reduction ◽

The Comparative Study ◽

Building Demolition

In recent year, Korea relies on imports for most of the iron ore, the main raw material of rebar, resulting in CO2 pollution with lots of energy consumption. Hereupon, this study carried out the research on the energy consumption and CO2 emissions of the recycled rebar using the wasted steel from building demolition. For that, this study worked out the energy consumption and CO2 emissions in the process of generation, transportation and production of wasted steel and, on the basis of which, it conducted the comparative study with virgin materials. The major research results are as follows: First, the energy consumption and CO2 emissions of the recycled rebar were found to be highest in the process of its production at 89.2% and 85%, respectively. In addition, in the comparison between recycled rebar and virgin material, the former was found to be most advantageous in energy consumption. On the contrary, as for CO2 emissions, the recycled rebar showed a 88.3% reduction possibility of greenhouse gas (GHG) emissions comparing to statistics of input-output analysis based on competition inducement coefficient, but it was found to be more disadvantageous from the perspective of GHG reduction than the statistics of input-output analysis based on non-competition inducement coefficient.

Download Full-text