scholarly journals Tensile Properties and Fracture Mechanisms of Corn Bract for Corn Peeling Device Design

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 796
Author(s):  
Zhenye Li ◽  
Jun Fu ◽  
Xiwen Luo
Keyword(s):  
Tensile Properties ◽  
Leaf Blade ◽  
Minimum Energy ◽  
Energy Performance ◽  
Growth Direction ◽  
Experimental Results ◽  
Fracture Mechanisms ◽  
Longitudinal Vein ◽  
Value Range ◽  
Pulling Force

This paper describes the physical and tensile properties of corn bracts during a whole harvest period by using two corn cultivars, aiming to realize efficient peeling with minimum energy performance and decrease the incidence of ear damage. The value range and change rule of tensile properties were obtained by combining mechanical experiments and numerical statistics. Meanwhile, mathematical models were established for tensile properties depending on bract moisture content and bract thickness. The experimental results show that the tensile properties of leaf blade were affected by the orientation between pulling force and longitudinal vein, and that parallel orientation was greater than perpendicular. Further, the tensile properties of leaf sheaths depended on the angle between pulling force and natural growth direction of the bract in the following order: 0° > 90° > 180°. A larger pulling force angle can improve the probability of bract fracturing at the root of leaf sheaths, which helps reduce bract residue on the peduncle. In addition, the fracture mechanisms of leaf blades and sheaths were expressed from physiological and morphological perspectives. The experimental results are believed to be able to provide theoretical guidance by which to design and optimize corn-peeling devices.

Net zero carbon: Energy performance targets for offices

2021 ◽  
Vol 42 (3) ◽  
pp. 349-369
Author(s):  
Robert Cohen ◽  
Karl Desai ◽  
Jennifer Elias ◽  
Richard Twinn
Keyword(s):  
Energy Efficiency ◽  
Minimum Energy ◽  
Energy Performance ◽  
Consultation Process ◽  
Net Zero ◽  
Extensive Consultation ◽  
Operational Energy ◽  
Legislative Framework ◽  
Zero Carbon ◽  
The Uk

The UKGBC Net Zero Carbon Buildings Framework was published in April 2019 following an industry task group and extensive consultation process. The framework acts as guidance for achieving net zero carbon for operational energy and construction emissions, with a whole life carbon approach to be developed in the future. In consultation with industry, further detail and stricter requirements are being developed over time. In October 2019, proposals were set out for industry consultation on minimum energy efficiency targets for new and existing commercial office buildings seeking to achieve net zero carbon status for operational energy today, based on the performance levels that all buildings will be required to achieve by 2050. This was complemented by modelling work undertaken by the LETI network looking into net zero carbon requirements for new buildings. In January 2020 UKGBC published its guidance on the levels of energy performance that offices should target to achieve net zero and a trajectory for getting there by 2035. This paper describes the methodology behind and industry perspectives on UKGBC’s proposals which aim to predict the reduction in building energy intensity required if the UK’s economy is to be fully-powered by zero carbon energy in 2050. Practical application: Many developers and investors seeking to procure new commercial offices or undertake major refurbishments of existing offices are engaging with the ‘net zero carbon’ agenda, now intrinsic to the legislative framework for economic activity in the UK. A UKGBC initiative effectively filled a vacuum by defining a set of requirements including energy efficiency thresholds for commercial offices in the UK to be considered ‘net zero carbon’. This paper provides all stakeholders with a detailed justification for the level of these thresholds and what might be done to achieve them. A worked example details one possible solution for a new office.

Performance Improvements in Cooker-Top Gas Burners for Small Aspect Ratio Changes

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Robson L. Silva ◽  
Bruno V. Sant′Ana ◽  
José R. Patelli ◽  
Marcelo M. Vieira
Keyword(s):  
Energy Conversion ◽  
Fuel Consumption ◽  
Conversion Efficiency ◽  
Minimum Energy ◽  
Energy Conversion Efficiency ◽  
Energy Performance ◽  
Operating Conditions ◽  
Lower Fuel Consumption ◽  
Performance Improvements ◽  
Aspect Ratios

This paper aims to identify performance improvements in cooker-top gas burners for changes in its original geometry, with aspect ratios (ARs) ranging from 0.25 to 0.56 and from 0.28 to 0.64. It operates on liquefied petroleum gas (LPG) and five thermal power (TP) levels. Considering the large number of cooker-top burners currently being used, even slight improvements in thermal performance resulting from a better design and recommended operating condition will lead to a significant reduction of energy consumption and costs. Appropriate instrumentation was used to carry out the measurements and methodology applied was based on regulations from INMETRO (CONPET program for energy conversion efficiency in cook top and kilns), ABNT (Brazilian Technical Standards Normative) and ANP—National Agency of Petroleum, Natural Gas (NG) and Biofuels. The results allow subsidizing recommendations to minimum energy performance standards (MEPS) for residential use, providing also higher energy conversion efficiency and/or lower fuel consumption. Main conclusions are: (i) Smaller aspect ratios result in the same heating capacity and higher efficiency; (ii) higher aspect ratios (original burners) are fuel consuming and inefficient; (iii) operating conditions set on intermediate are lower fuel consumption without significant differences in temperature increases; (iv) Reynolds number lower than 500 provides higher efficiencies.

EFFECT OF FIBRE TREATMENT ON LONGITUDINAL AND TRANSVERSE TENSILE PROPERTIES OF UNIDIRECTIONAL KENAF COMPOSITE

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Norhashidah Manap ◽  
Aidah Jumahat ◽  
Napisah Sapiai
Keyword(s):  
Tensile Properties ◽  
Strain Curve ◽  
Natural Fibre ◽  
Filament Winding ◽  
Fracture Mechanisms ◽  
Positive Effects ◽  
Transverse Tensile ◽  
Kenaf Fibre ◽  
Naoh Treatment ◽  
Kenaf Composites

Kenaf fibre has become one of the best candidates to be used as reinforcement material in polymer composite. However, the adhesion between natural fibre and polymer is weak due to different polarity of natural fibre and hydrophobic polymer. This affects the properties of the composite. One of the method to overcome this compatibility issue is by treating the fibre using sodium hydroxide (NaOH). This study is aimed to evaluate the effect of NaOH treatment on longitudinal and transverse tensile properties of kenaf composites using three different concentration (3, 5, and 7 wt. % NaOH). The kenaf composite test specimens were prepared using filament winding and vacuum bagging techniques. The 0o and 90o tensile tests were conducted in accordance to ASTM standard D3039 in order to obtain longitudinal and transverse tensile properties of treated and untreated kenaf composites. The fracture surfaces of the specimens were observed using scanning electron microscope in order to identify fracture mechanisms involved during tension. NaOH treatment on kenaf fibre resulted in a significant improvement in longitudinal tensile modulus, strength and failure strain. This also indicates an improvement in toughness property as this can be observed through a larger area under graph of tensile stress-strain curve. The SEM micrographs showed that the interfacial adhesion between kenaf fibre and epoxy matrix was improved when the kenaf fibre was treated using NaOH. Therefore, NaOH treatment give positive effects on longitudinal and transverse tensile properties of kenaf composites. Kenaf composite treated with 7wt% NaOH showed the highest tensile strength for both longitudinal and transverse fibre directions.

Tensile Properties of Triaxially Woven Fabrics Under Biaxial Loading

1980 ◽  
Vol 102 (4) ◽  
pp. 327-332 ◽  
Author(s):  
P. Schwartz ◽  
R. E. Fornes ◽  
M. H. Mohamed
Keyword(s):  
Tensile Properties ◽  
Biaxial Loading ◽  
Unit Area ◽  
Woven Fabrics ◽  
Experimental Results ◽  
Cover Factor ◽  
Axes Of Symmetry ◽  
Good Agreement ◽  
Loading Analysis

Classical results in the behavior of woven fabrics are extended to the case of fabrics having three planar, nonorthogonal axes of symmetry (triaxial). The biaxial loading analysis due to Grosberg is extended to the loading of triaxial fabrics in the machine and cross-machine directions in an attempt to predict fabric modulus during the crimp removal stage. Preliminary experimental results showing reasonably good agreement with moderately open fabrics are given. In addition, relationships are developed to allow the construction of conventional fabrics which are equivalent to triaxial fabrics in terms of cover factor and intersections or interfacings per unit area.

scholarly journals The Impact of Minimum Energy Performance Standards (MEPS) Regulation on Electricity Saving in Malaysia

2018 ◽  
Vol 341 ◽  
pp. 012022
Author(s):  
Siti Fatihah Salleh ◽  
Mohd Eqwan Roslan ◽  
Aishah Mohd Isa ◽  
Mohd Faizal Basri Nair ◽  
Siti Syafiqah Salleh
Keyword(s):  
Minimum Energy ◽  
Performance Standards ◽  
Energy Performance ◽  
Electricity Saving ◽  
The Impact

scholarly journals A Long-term Strategy for Energy and Cost Performance Improvement of Existing Residential Buildings: Step-by-step Renovation in Turkey

2019 ◽  
Vol 111 ◽  
pp. 03040
Author(s):  
Touraj Ashrafian ◽  
Zerrin Yilmaz ◽  
Nazanin Moazzen
Keyword(s):  
Cost Analysis ◽  
Energy Efficient ◽  
Financial Incentives ◽  
Residential Buildings ◽  
Minimum Energy ◽  
Energy Performance ◽  
Optimal Level ◽  
Proper Solution ◽  
Existing Building ◽  
The Cost

Recast version of Energy Performance of Building Directive (EPBD-Recast) obligate member states to keep the cost analysis in parallel with the energy analysis during the renovation actions for the existing building by taking the cost-optimal level of minimum energy performance requirement to the account. Although this cost-optimal level is indicating the minimum cost level for a period, it can provide buildings’ owners with an enormous initial cost. One of the most challenging barriers to energy efficient and cost-optimal renovation of existing buildings is the reluctance of owners to involve in their project as an investor due to the high cost of application. Particularly in developing countries, such reluctance is more tangible as the governments are not capable of providing enough financial incentives for owners due to a large number of buildings that should be renovated and small available budget. A proper solution for the problem is to divide necessary actions for each building to certain sub-actions and apply them as a step-by-step renovation project. On the other hand, the progressive application of renovation activities has some restrictions. It is necessary to define the due amount for households and keep the cost of each step within the payable range. Moreover, the low rate of building renovation which affects the EU goals can be improved remarkably by application of step-by-step actions not only by increasing the number of owners’ contributions but also by improving the time of implementation, proper distribution of skilled labours and directed economic resources. This paper aims to assess the step-by-step application of the energy efficient renovation actions through energy and cost analysis under Turkey’s climatic, economic and sociological conditions. One of 26 reference residential buildings in Turkey is analysed in this paper. The due amount for each step is defined, and some renovation actions and their combinations applied to the case building and the results compared with the base condition. Then a proper combination of measures established based on the cost-optimal analyses. These appropriately combined actions are then divided into some sub-actions; following this, cost and energy studies are conducted again to determine the appropriate arrangement of sub-actions.

scholarly journals How Climate Trends Impact on the Thermal Performance of a Typical Residential Building in Madrid

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 237 ◽  
Author(s):  
S. Soutullo ◽  
E. Giancola ◽  
M. J. Jiménez ◽  
J. A. Ferrer ◽  
M. N. Sánchez
Keyword(s):  
Residential Buildings ◽  
Minimum Energy ◽  
Residential Building ◽  
Energy Performance ◽  
Weather Data ◽  
Design Strategies ◽  
Climate Trends ◽  
Average Value ◽  
Minimum Energy Consumption ◽  
The Impact

Based on the European energy directives, the building sector has to provide comfortable levels for occupants with minimum energy consumption as well as to reduce greenhouse gas emissions. This paper aims to compare the impact of climate change on the energy performance of residential buildings in order to derive potential design strategies. Different climate file inputs of Madrid have been used to quantify comparatively the thermal needs of two reference residential buildings located in this city. One of them represents buildings older than 40 years built according to the applicable Spanish regulations prior to 1979. The other refers to buildings erected in the last decade under more energy-restrictive constructive regulations. Three different climate databases of Madrid have been used to assess the impact of the evolution of the climate in recent years on the thermal demands of these two reference buildings. Two of them are typical meteorological years (TMY) derived from weather data measured before 2000. On the contrary, the third one is an experimental file representing the average values of the meteorological variables registered in Madrid during the last decade. Annual and monthly comparisons are done between the three climate databases assessing the climate changes. Compared to the TMYs databases, the experimental one records an average air temperature of 1.8 °C higher and an average value of relative humidity that is 9% lower.

A study on a new criterion for minimum-energy perfect control in the state-space framework

2019 ◽  
Vol 233 (7) ◽  
pp. 779-787 ◽  
Author(s):  
Wojciech P Hunek ◽  
Marek Krok
Keyword(s):  
Energy Cost ◽  
Control Algorithm ◽  
Minimum Energy ◽  
Energy Performance ◽  
Control Law ◽  
Performance Simulation ◽  
New Approach ◽  
Energy Behavior ◽  
New Criterion ◽  
Made In

In this article, an advanced study concerning the energy cost of the perfect control algorithm is provided. An application of different nonunique matrix inverses into perfect control law has resulted in remarkable influence on both control and state signals. Following the newly obtained issues, covering the minimum-energy behavior, a new related criterion is proposed here. Based on deterministic norm we can, in a simple way, estimate the crucial energy performance. Simulation examples made in MATLAB/Simulink environment show the high potential of a new approach considered in the article.

scholarly journals Spaces in-between impacts on indoor environment and energy efficiency in dwellings

2019 ◽  
Vol 282 ◽  
pp. 02071
Author(s):  
Catarina F. T. Ribeiro ◽  
Nuno M. M. Ramos ◽  
Inês Flores-Colen
Keyword(s):  
Energy Consumption ◽  
Indoor Environment ◽  
Minimum Energy ◽  
Environmental Parameters ◽  
Holistic Approach ◽  
Energy Performance ◽  
Indoor Environmental Quality ◽  
Climatic Regions ◽  
Minimum Energy Consumption ◽  
Acoustic Comfort

Throughout history, it has always been recognised that the spaces in-between in dwellings have the advantage of working as environmental buffer spaces. The aim of this paper is to provide a literature review of the different spaces in-between in dwellings – balconies, shaded balconies and glazed balconies - and their impacts on comfort and on energy performance. The effects of the spaces in-between depend on their design, on the characteristics of the buildings and on the surroundings. They have important impacts on the four factors that contribute to the indoor environmental quality: thermal comfort, lighting comfort, acoustic comfort and indoor air quality. These factors are interrelated and the lack of balance between them can lead to poor indoor environmental conditions and to excessive energy consumption. Based on the review, a synthesis of the key environmental parameters that can be used as indicators for those factors is established. The impacts of spaces in-between on the factors and sub-factors of indoor environment are defined, considering different climatic regions. A holistic approach that conciliates all the above-mentioned factors should be a contribution to the design of spaces in-between in both new construction and rehabilitation projects, in order to achieve better indoor environment with minimum energy consumption.

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