scholarly journals Preparation of microencapsulated PCMs for energy saving and thermal comfort of buildings

2021 ◽  
Vol 23 (09) ◽  
pp. 277-287
Author(s):  
Ashraf Mohamed Heniegal ◽  
◽  
Omar Mohamed Omar Ibrahim ◽  
Nour Bassim Frahat ◽  
Mohamed Amin ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Chemical Interaction ◽  
Spherical Shape ◽  
Building Envelope ◽  
Scanning Calorimetry ◽  
Indoor Temperature ◽  
New Techniques ◽  
Consumption Energy ◽  
Local Materials ◽  
Regular Spherical Shape

Energy improvement techniques for buildings are among the modern studies that concentrate on new techniques and methods of saving energy and improving the thermal performance in buildings. This research aims to prepare microencapsulated-PCMs (micro-PCMs) by using local materials and studied the influence of using micro-PCMs on thermal performance improvement and PCMs leakage problems improvement. The micro-PCMs of paraffin wax were prepared as the core PCMs materials while the melamine-formaldehyde polymer as the shell. The micro-PCMs were characterized through scanning electron-microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Analysis results showed the prepared micro-PCMs present a regular spherical shape and confirm that the formation composite of the shell effectively encapsulated the cores. Furthermore, the absence of chemical interaction between the MF and the PW components. The micro-PCM have potential for architectural applications in the building-envelope to store thermal energy, provide indoor-temperature at the comfortable range, and reduce the consumption energy in buildings.

scholarly journals Preparation and Characterisation of Nobiletin-Loaded Nanostructured Lipid Carriers

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Huang ◽  
Huating Dou ◽  
Houjiu Wu ◽  
Zhigao Sun ◽  
Hua Wang ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Chemical Interaction ◽  
Amorphous State ◽  
Spherical Shape ◽  
Entrapment Efficiency ◽  
Nanostructured Lipid Carriers ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Lipid Mixture ◽  
Food Response

The objective of this manuscript was to investigate and optimise the potential of nanostructured lipid carriers (NLCs) as a carrier system for nobiletin (NOB), which was prepared by high-pressure homogenisation method. Additionally, this study was focused on the application of NOB-loaded NLC (NOB-NLC) in functional food. Response surface method with a three-level Box–Behnken design was validated through analysis of variance, and the robustness of the design was confirmed through the correspondence between the values measured in the experiments and the predicted ones. Properties of the prepared NOB-NLC, such as Z-average, polydispersity, entrapment efficiency, zeta potential, morphology, and crystallinity, were investigated. NOB-NLC exhibited a spherical shape with a diameter of 112.27 ± 5.33 nm, zeta potential of −35.1 ± 2.94 mV, a polydispersity index of 0.251 ± 0.058, and an EE of 81.06%  ±  6.02%. Results from X-ray diffraction and differential scanning calorimetry of NOB-NLC reviewed that the NOB crystal might be converted to an amorphous state. Fourier transform infrared spectroscopic analysis demonstrated that chemical interaction was absent between the compound and lipid mixture in NOB-NLC.

scholarly journals Total Solar Reflectance Optimization of the External Paint Coat in Residential Buildings Located in Mediterranean Climates

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2729
Author(s):  
Tiago Souto ◽  
Margarida Almeida ◽  
Vítor Leal ◽  
João Machado ◽  
Adélio Mendes
Keyword(s):  
Thermal Performance ◽  
Energy Savings ◽  
Residential Buildings ◽  
Thermal Characteristics ◽  
Residential Building ◽  
Building Envelope ◽  
R Software ◽  
Indoor Temperature ◽  
Solar Reflectance ◽  
Parametric Studies

This work addresses the effect of the total solar reflectance (TSR) value of paints applied in residential buildings upon their thermal performance. A semi-detached residential building was modeled in the ESP-r software, and taken as the basis for parametric studies which assessed the effects of variations in (i) the TSR values; (ii) the thermal characteristics of the building envelope; (iii) the location/climate; and: (iv) the way how the indoor temperature is controlled. The parametric studies were used to find optimal TSR values for each combination of Location + Building envelope characteristics (mainly the existence of thermal insulation). It was concluded that paints having a carefully chosen TSR value lead to better indoor thermal temperatures if the buildings have no mechanical heating or cooling, or to energy savings of up to 32% if they do.

scholarly journals Comparison and analyses of two thermal performance evaluation models for a public building

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 916-926
Author(s):  
Xuemei Sun ◽  
Saihong Zhu ◽  
Hengxuan Zhu ◽  
Runze Duan ◽  
Jin Wang
Keyword(s):  
Water Temperature ◽  
Thermal Performance ◽  
Building Envelope ◽  
Thermal Mass ◽  
Heating Season ◽  
Mass Model ◽  
Indoor Temperature ◽  
Public Building ◽  
Evaluation Models ◽  
Supply Water

Abstract Recently, investigations on building thermal inertia are mainly involved with the materials of the building envelope. Usually, other influencing factors are ignored, such as room ventilation, indoor heat storage, indoor cold source, indoor heat source and human behavior. In this paper, two models based on thermodynamics are given to evaluate building thermal performance. One is thermal mass model, and the other one is thermal reserve coefficient model. Based on thermal response testing data in a non-heating season, the thermal mass model was adopted to classify the envelope type, and the delay rules between the indoor temperature and the outdoor meteorological parameters are analyzed. In a heating season, the delay rules among the outdoor temperature, indoor temperature and supply water temperature are obtained by changing the supply water temperature. Thermal performance of the targeted building is evaluated with the thermal reserve coefficient model. For the same public building, two evaluation models tend to be consistent. These two evaluation models presented in this paper can be applied for the optimal design of buildings envelope.

scholarly journals Wastes from Agricultural Silage Film Recycling Line as a Potential Polymer Materials

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1383
Author(s):  
Jerzy Korol ◽  
Aleksander Hejna ◽  
Klaudiusz Wypiór ◽  
Krzysztof Mijalski ◽  
Ewelina Chmielnicka
Keyword(s):  
Vinyl Acetate ◽  
Thermal Performance ◽  
Mechanical Performance ◽  
Ethylene Vinyl Acetate ◽  
Tensile Tests ◽  
Solid Particles ◽  
Polymer Materials ◽  
Slight Reduction ◽  
Scanning Calorimetry ◽  
Crystallinity Degree

The recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for potential methods for their utilization. In the presented work, we investigated the recycling potential of wastes originated from the agricultural films recycling line. Their structure and properties were analyzed, and they were modified with 2.5 wt % of commercially available compatibilizers. The mechanical and thermal performance of modified wastes were evaluated by tensile tests, thermogravimetric analysis, and differential scanning calorimetry. It was found that incorporation of such a small amount of modifiers may overcome the drawbacks caused by the presence of impurities. The incorporation of maleic anhydride-grafted compounds enhanced the tensile strength of wastes by 13–25%. The use of more ductile compatibilizers—ethylene-vinyl acetate and paraffin increased the elongation at break by 55–64%. The presence of compatibilizers also reduced the stiffness of materials resulting from the presence of solid particles. It was particularly emphasized for styrene-ethylene-butadiene-styrene and ethylene-vinyl acetate copolymers, which caused up to a 20% drop of Young’s modulus. Such effects may facilitate the further applications of analyzed wastes, e.g., in polymer film production. Thermal performance was only slightly affected by compatibilization. It caused a slight reduction in polyethylene melting temperatures (up to 2.8 °C) and crystallinity degree (up to 16%). For more contaminated materials, the addition of compatibilizers caused a minor reduction in the decomposition onset (up to 6 °C). At the same time, for the waste after three washing cycles, thermal stability was improved. Moreover, depending on the desired properties and application, materials do not have to go through the whole recycling line, simplifying the process, reducing energy and water consumption. The presented results indicate that it is possible to efficiently use the materials, which do not have to undergo the whole recycling process. Despite the presence of impurities, they could be applied in the manufacturing of products which do not require exceptional mechanical performance.

scholarly journals Online Implementation of a Soft Actor-Critic Agent to Enhance Indoor Temperature Control and Energy Efficiency in Buildings

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 997
Author(s):  
Davide Coraci ◽  
Silvio Brandi ◽  
Marco Savino Piscitelli ◽  
Alfonso Capozzoli
Keyword(s):  
Energy Consumption ◽  
Temperature Control ◽  
Weather Conditions ◽  
Heating System ◽  
Building Envelope ◽  
Indoor Temperature ◽  
Model Free ◽  
Occupancy Patterns ◽  
Online Implementation ◽  
Indoor Temperature Control

Recently, a growing interest has been observed in HVAC control systems based on Artificial Intelligence, to improve comfort conditions while avoiding unnecessary energy consumption. In this work, a model-free algorithm belonging to the Deep Reinforcement Learning (DRL) class, Soft Actor-Critic, was implemented to control the supply water temperature to radiant terminal units of a heating system serving an office building. The controller was trained online, and a preliminary sensitivity analysis on hyperparameters was performed to assess their influence on the agent performance. The DRL agent with the best performance was compared to a rule-based controller assumed as a baseline during a three-month heating season. The DRL controller outperformed the baseline after two weeks of deployment, with an overall performance improvement related to control of indoor temperature conditions. Moreover, the adaptability of the DRL agent was tested for various control scenarios, simulating changes of external weather conditions, indoor temperature setpoint, building envelope features and occupancy patterns. The agent dynamically deployed, despite a slight increase in energy consumption, led to an improvement of indoor temperature control, reducing the cumulative sum of temperature violations on average for all scenarios by 75% and 48% compared to the baseline and statically deployed agent respectively.

Evaluating dynamic thermal performance of building envelope components using small-scale calibrated hot box tests

2021 ◽  
pp. 111342
Author(s):  
Zhenglai Shen ◽  
Adam L. Brooks ◽  
Yawen He ◽  
Som S. Shrestha ◽  
Hongyu Zhou
Keyword(s):  
Thermal Performance ◽  
Building Envelope ◽  
Small Scale

scholarly journals Thermal Impacts of Vertical Greenery Systems

2014 ◽  
Vol 14 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Tabassom Safikhani ◽  
Aminatuzuhariah Megat Abdullah ◽  
Dilshan Remaz Ossen ◽  
Mohammad Baharvand
Keyword(s):  
Thermal Performance ◽  
Modern Architecture ◽  
Small Scale ◽  
Heat Transmission ◽  
Indoor Temperature ◽  
Experimental Procedure ◽  
Hot And Humid Climates ◽  
Living Wall ◽  
Green Façade ◽  
Green Facade

Abstract - Using vertical greenery systems to reduce heat transmission is becoming more common in modern architecture. Vertical greenery systems are divided into two main categories; green facades and living walls. This study aims to examine the thermal performance of vertical greenery systems in hot and humid climates. An experimental procedure was used to measure indoor temperature and humidity. These parameters were also measured for the gap between the vertical greenery systems and wall surfaces. Three boxes were used as small-scale rooms. Two boxes were provided with either a living wall or a green facade and one box did not have any greenery (benchmark). Blue Trumpet Vine was used in the vertical greenery systems. The data were recorded over the course of three sunny days in April 2013. An analyses of the results showed that the living wall and green facade reduced indoor temperature up to 4.0 °C and 3.0 °C, respectively. The living wall and green facade also reduced cavity temperatures by 8.0 °C and 6.5 °C, respectively.

scholarly journals Preparation, characterization and scale-up of sesamol loaded solid lipid nanoparticles

2012 ◽  
Vol 2 (1) ◽  
pp. 8 ◽  
Author(s):  
Vandita Kakkar ◽  
Indu Pal Kaur
Keyword(s):  
Solid Lipid Nanoparticles ◽  
Scale Up ◽  
Spherical Shape ◽  
Entrapment Efficiency ◽  
Lipid Nanoparticles ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Solid Lipid ◽  
Transmission Electron ◽  
The Brain

Sesamol loaded solid lipid nanoparticles (SSLNs) were prepared with the aim of minimizing its distribution to tissues and achieving its targeting to the brain. Three scale-up batches (100x1 L) of S-SLNs were prepared using a microemulsification technique and all parameters were statistically compared with the small batch (1x;10 mL). S-SLNs with a particle size of less than 106 nm with a spherical shape (transmission electron microscopy) were successfully prepared with a total drug content and entrapment efficiency of 94.26±2.71% and 72.57±5.20%, respectively. Differential scanning calorimetry and infrared spectroscopy confirmed the formation of lipidic nanoparticles while powder X-ray diffraction revealed their amorphous profile. S-SLNs were found to be stable for three months at 5±3°C in accordance with International Conference on Harmonisation guidelines. The SLN preparation process was successfully scaled-up to a 100x batch on a laboratory scale. The procedure was easy to perform and allowed reproducible SLN dispersions to be obtained.

scholarly journals Microstructure and mechanical properties of slowly cooled Cu47.5Zr47.5Al5

2007 ◽  
Vol 22 (2) ◽  
pp. 326-333 ◽  
Author(s):  
J. Das ◽  
S. Pauly ◽  
C. Duhamel ◽  
B.C. Wei ◽  
J. Eckert
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Volume Fraction ◽  
Spherical Shape ◽  
High Yield ◽  
High Yield Strength ◽  
Scanning Calorimetry ◽  
Arc Melting ◽  
Martensite Matrix

Cu47.5Zr47.5Al5 was prepared by arc melting and solidified in situ by suction casting into 2–5-mm-diameter rods under various cooling rates (200–2000 K/s). The microstructure was investigated along the length of the rods by electron microscopy, differential scanning calorimetry and mechanical properties were investigated under compression. The microstructure of differently prepared specimens consists of macroscopic spherical shape chemically inhomogeneous regions together with a low volume fraction of randomly distributed CuZr B2 phase embedded in a 2–7 nm size clustered “glassy-martensite” matrix. The as-cast specimens show high yield strength (1721 MPa), pronounced work-hardening behavior up to 2116 MPa and large fracture strain up to 12.1–15.1%. The fracture strain decreases with increasing casting diameter. The presence of chemical inhomogenities and nanoscale “glassy-martensite” features are beneficial for improving the inherent ductility of the metallic glass.

scholarly journals Development and evaluation of coenzyme Q10 loaded solid lipid nanoparticle hydrogel for enhanced dermal delivery

2013 ◽  
Vol 63 (4) ◽  
pp. 517-529 ◽  
Author(s):  
Emrah Korkm ◽  
Evren H. Gokce ◽  
Ozgen Ozer
Keyword(s):  
Coenzyme Q10 ◽  
High Speed ◽  
Antioxidant Properties ◽  
Spherical Shape ◽  
Entrapment Efficiency ◽  
Tween 80 ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Solid Lipid

Abstract Coenzyme Q10 (Q10) loaded solid lipid nanoparticles (SLN) were prepared by the high speed homogenization method and incorporated into Carbopol 974P hydrogels. Compritol 888 ATO (C888) was employed as the lipid base; Poloxamer 188 (P188) and Tween 80 (Tw80) were used as surfactant and co-surfactant. Optimum particle size with narrow distribution was obtained as 152.2 nm for blank and 142.4 nm for Q10 loaded SLNs. The overall charge of loaded SLNs was -13.7 ± 1.3 mV. Q10 entrapment efficiency was 89 % and the production yield was 94 %. Transmission electron microscopy analysis provided evidence of colloidal size, spherical shape while differential scanning calorimetry analysis confirmed recrystallization of the lipid after the preparation of SLNs. Trolox equivalent antioxidant capacity (TEAC) analysis has shown that antioxidant potential of Q10 can be protected in SLNs. Rheological characteristics demonstrated that the SLN incorporating gels were shear thinning and the mechanical strength of the gels was suitable for topical application. Diffusion studies from rat abdominal skin revealed that the delivery of Q10 was doubled in SLN incorporating gels, approximately 40 μg cm-2, in comparison with gels prepared with only Q10 (not incorporated in SLNs). As a result, it can be stated that Q10-SLN loaded gels can be successful delivery systems for carrying Q10 efficiently into the skin without losing its antioxidant properties.

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