scholarly journals Effects of Particle Size on the Dielectric, Mechanical, and Thermal Properties of Recycled Borosilicate Glass-Filled PTFE Microwave Substrates

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2449
Author(s):  
Ibrahim Abubakar Alhaji ◽  
Zulkifly Abbas ◽  
Mohd Hafiz Mohd Zaid ◽  
Ahmad Mamoun Khamis
Keyword(s):  
Dielectric Properties ◽  
Moisture Absorption ◽  
Powder Processing ◽  
Coefficient Of Thermal Expansion ◽  
Low Cost ◽  
Signal Transmission ◽  
Filler Particle ◽  
Mechanical And Thermal Properties ◽  
Filler Size ◽  
The Mean

Low dielectric loss and low-cost recycled borosilicate (BRS) glass-reinforced polytetrafluoroethylene (PTFE) composites were fabricated for microwave substrate applications. The composites were prepared through a dry powder processing technique by dispersing different micron sizes (25 µm, 45 µm, 63 µm, 90 µm, and 106 µm) of the recycled BRS filler in the PTFE matrix. The effect of the filler sizes on the composites’ thermal, mechanical, and dielectric properties was studied. The dielectric properties of the composites were characterised in the frequency range of 1–12 GHz using an open-ended coaxial probe (OCP) connected to a vector network analyser (VNA). XRD patterns confirmed the phase formation of PTFE and recycled BRS glass. The scanning electron microscope also showed good filler dispersion at larger filler particle sizes. In addition, the composites’ coefficient of thermal expansion and tensile strength decreased from 12.93 MPa and 64.86 ppm/°C to 7.12 MPa and 55.77 ppm/°C when the filler size is reduced from 106 μm to 25 μm. However, moisture absorption and density of the composites increased from 0.01% and 2.17 g/cm3 to 0.04% and 2.21 g/cm3. The decrement in filler size from 106 μm to 25 μm also increased the mean dielectric constant and loss tangent of the composites from 2.07 and 0.0010 to 2.18 and 0.0011, respectively, while it reduced the mean signal transmission speed from 2.088 × 108 m/s to 2.031 × 108 m/s. The presented results showed that PTFE/recycled BRS composite exhibited comparable characteristics with commercial high-frequency laminates.

scholarly journals Utility-Scale PV-Battery versus CSP-Thermal Storage in Morocco: Storage and Cost Effect under Penetration Scenarios

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4675
Author(s):  
Ayat-allah Bouramdane ◽  
Alexis Tantet ◽  
Philippe Drobinski
Keyword(s):  
Storage Capacity ◽  
Low Cost ◽  
Thermal Storage ◽  
Solar Pv ◽  
Storage Duration ◽  
Maximum Cost ◽  
Pv Inverter ◽  
The Mean ◽  
Mean Variance Portfolio ◽  
Utility Scale

In this study, we examine how Battery Storage (BES) and Thermal Storage (TES) combined with solar Photovoltaic (PV) and Concentrated Solar Power (CSP) technologies with an increased storage duration and rental cost together with diversification would influence the Moroccan mix and to what extent the variability (i.e., adequacy risk) can be reduced; this is done using recent (2013) cost data and under various penetration scenarios. To do this, we use MERRA-2 climate reanalysis to simulate hourly demand and capacity factors (CFs) of wind, solar PV and CSP without and with increasing storage capabilities—as defined by the CSP Solar Multiple (SM) and PV Inverter Loading Ratio (ILR). We adjust these time series to observations for the four Moroccan electrical zones over the year 2018. Our objective is to maximize the renewable (RE) penetration and minimize the imbalances between RE production and consumption considering three optimization strategies. We analyze mixes along Pareto fronts using the Mean-Variance Portfolio approach—implemented in the E4CLIM model—in which we add a maximum-cost constraint to take into account the different rental costs of wind, PV and CSP. We propose a method to calculate the rental cost of storage and production technologies taking into account the constraints on storage associated with the increase of SM and ILR in the added PV-BES and CSP-TES modules, keeping the mean solar CFs fixed. We perform some load bands-reduction diagnostics to assess the reliability benefits provided by each RE technology. We find that, at low penetrations, the maximum-cost budget is not reached because a small capacity is needed. The higher the ILR for PV, the larger the share of PV in the mix compared to wind and CSP without storage is removed completely. Between PV-BES and CSP-TES, the latter is preferred as it has larger storage capacity and thus stronger impact in reducing the adequacy risk. As additional BES are installed, more than TES, PV-BES is favored. At high penetrations, optimal mixes are impacted by cost, the more so as CSP (resp., PV) with high SM (resp., ILR) are installed. Wind is preferably installed due to its high mean CF compared to cost, followed by either PV-BES or CSP/CSP-TES. Scenarios without or with medium storage capacity favor CSP/CSP-TES, while high storage duration scenarios are dominated by low-cost PV-BES. However, scenarios ignoring the storage cost and constraints provide more weight to PV-BES whatever the penetration level. We also show that significant reduction of RE variability can only be achieved through geographical diversification. Technological complementarity may only help to reduce the variance when PV and CSP are both installed without or with a small amount of storage. However, the diversification effect is slightly smaller when the SM and ILR are increased and the covariances are reduced as well since mixes become less diversified.

scholarly journals Economic Burden of Colorectal Cancer: A Case of Fars, Iran

2021 ◽  
Vol 28 ◽  
pp. 107327482110099
Author(s):  
Abdosaleh Jafari ◽  
Peyman Mehdi Alamdarloo ◽  
Mehdi Dehghani ◽  
Peivand Bastani ◽  
Ramin Ravangard
Keyword(s):  
Colorectal Cancer ◽  
Economic Burden ◽  
Purchasing Power Parity ◽  
Annual Cost ◽  
Low Cost ◽  
Direct Costs ◽  
Fars Province ◽  
Power Parity ◽  
Medical Sciences ◽  
The Mean

Among cancers, colorectal cancer is the third most common cancer in the world and the fourth leading cause of cancer deaths worldwide. Some studies have shown that the incidence of colorectal cancer is increasing in Iran and in Fars province. The present study aimed to determine the economic burden of colorectal cancer in patients referred to the referral centers affiliated to Iran, Shiraz University of Medical Sciences in 2019 from the patients’ perspective. This is a partial economic evaluation and a cost-of-illness study conducted cross-sectionally in 2019. All the patients with colorectal cancer who had been referred to the referral centers affiliated to Iran, Shiraz University of Medical Sciences, and had medical records were studied through the census method (N = 96). A researcher-made data collection form was used to collect the cost data. The prevalence-based and bottom-up approaches were also used in this study. The human capital approach was applied to calculate indirect costs. The mean annual cost per patient with colorectal cancer in the present study was $10930.98 purchasing power parity (PPP) (equivalent to 5745.29 USD), the main part of which was the medical direct costs (74.86%). Also, among the medical direct costs per patient, the highest were those of surgeries (41.7%). In addition, the mean annual cost per patient with colorectal cancer in the country was $ 116917762 PPP (equivalent to 61451621.84 USD) in 2019. Regarding the considerable economic burden of colorectal cancer and in order to reduce the costs, these suggestions can be made: increasing the number of specialized beds through the cooperation of health donors, establishing free or low-cost accommodation centers for patients and their companions near the medical centers, using the Internet and cyberspace technologies to follow up the treatment of patients, and increasing insurance coverage and government drug subsidies on drug purchase.

scholarly journals Research on Thermal Stability and Properties of Ca3ZrSi2O9 as Potential T/EBC Materials

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 583
Author(s):  
Yangyang Pan ◽  
Bo Liang ◽  
Yaran Niu ◽  
Dijuan Han ◽  
Dongdong Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Mechanical And Thermal Properties ◽  
Self Healing ◽  
Barrier Coating

In this study, a new coating material for thermal barrier coating (TBC) or environment barrier coating (EBC) application, Ca3ZrSi2O9 (CZSO), was synthesized and prepared by atmospheric plasma spray (APS) technology. The evolution of the phases and microstructures of the coatings with different thermal-aged were characterized by XRD, XRF, EDS and SEM, respectively. The thermal stability was measured by TG-DTA and DSC. The mechanical and thermal properties, including Vickers hardness (HV), fracture toughness (KIC), thermal conductivity () and coefficient of thermal expansion (CTE) were focused on. It was found that the as-sprayed CZSO coating contained amorphous phase. Crystalline transformation happened at 900–960 ∘C and no mass changes took place from room temperature (RT) to 1300 ∘C. The phenomena of microcrack self-healing and composition uniformity were observed during thermal aging. The of coating was very low at about 0.57–0.80 Wm−1K−1 in 200–1200 ∘C. The combined properties indicated that the CZSO coating might be a potential T/EBC material.

Novel soluble polyimides containing pyridine and fluorinated units: preparation, characterization, and optical and dielectric properties

RSC Advances ◽  
2016 ◽  
Vol 6 (26) ◽  
pp. 21662-21671 ◽  
Author(s):  
Weibing Dong ◽  
Yue Guan ◽  
Dejing Shang
Keyword(s):  
Dielectric Constant ◽  
Thermal Properties ◽  
Dielectric Properties ◽  
Low Dielectric Constant ◽  
Mechanical And Thermal Properties ◽  
Polyimide Films ◽  
Low Dielectric

To acquire low dielectric constant polyimide films with good mechanical and thermal properties and low CTE applied in microelectronic fields, three novel polyimides containing pyridine and –C(CF3)2– groups were firstly designed and synthesized.

scholarly journals Low-Cost Customized Cranioplasty with Polymethyl Methacrylate Using 3D Printer Generated Mold: An Institutional Experience and Review of Literature

2021 ◽  
Author(s):  
Ankit Chaudhary ◽  
Virendra Deo Sinha ◽  
Sanjeev Chopra ◽  
Jitendra Shekhawat ◽  
Gaurav Jain
Keyword(s):  
Polymethyl Methacrylate ◽  
Bone Fractures ◽  
Low Cost ◽  
Operating Time ◽  
Three Dimensional ◽  
Wound Dehiscence ◽  
3D Printer ◽  
Skull Defects ◽  
Aesthetic Appearance ◽  
The Mean

Abstract Background Cranioplasty is performed to repair skull defects and to restore normal skull anatomy. Optimal reconstruction remains a topic of debate. Autologous bone flap is the standard option but it may not be available due to traumatic bone fractures, bone infection, and resorption. The authors present their experience with prefabrication of precise and low-cost polymethyl methacrylate (PMMA) mold using three-dimensional (3D) digital printing. Methods A total of 30 patients underwent cranioplasty between March 2017 and September 2019 at Sawai Man Singh Medical College Jaipur, India. Preoperative data included diagnosis for which decompressive craniectomy was done and Glasgow coma scale score. Intraoperative data included operating time. Postoperative data included cosmetic outcome in the form of cranial contour and margins, complications such as infection, seroma, implant failure, wound dehiscence, and hematoma. Results Patient age at cranioplasty ranged from 12 to 63 years with a mean age of 36.7 years. The mean operating time was 151.6 minutes (range 130–190 minutes). The mean follow-up period was 8 months (range 6–13 months). Postoperative wound dehiscence developed in one case (3.3%). Cranial contour and approximation of the margins were excellent and aesthetic appearance improved in all patients. Conclusion Low-cost PMMA implant made by digital 3D printer mold is associated with reconstruction of the deformed skull contour giving satisfactory results to the patient and his family members, at a low cost compared with other commercially available implants. This technique could be a breakthrough in cranioplasty.

Evaluation of CeSZ Thermal Barrier Coatings for Diesels

2000 ◽  
Author(s):  
P.J. Huang ◽  
J.J. Swab ◽  
P.J. Patel ◽  
W.S. Chu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Barrier Coatings ◽  
Coefficient Of Thermal Expansion ◽  
Fuel Efficiency ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Mechanical And Thermal Properties ◽  
Barrier Coatings ◽  
Spray Process

Abstract The development of thermal barrier coatings (TBCs) for diesel engines has been driven by the potential improvements in engine power and fuel efficiency that TBCs represent. TBCs have been employed for many years to reduce corrosion of valves and pistons because of their high temperature durability and thermal insulative properties. There are research programs to improve TBCs wear resistance to allow for its use in tribologically intensive areas of the engine. This paper will present results from tribological tests of ceria stabilized zirconia (CeSZ). The CeSZ was applied by atmospheric plasma spray process. Various mechanical and thermal properties were measured including wear, coefficient of thermal expansion, thermal conductivity, and microhardness. The results show the potential use of CeSZ in wear sensitive applications in diesel applications. Keywords: Thermal Barrier Coating, Diesel Engine, Wear, Thermal Conductivity, and Thermal Expansion

scholarly journals Measurements of Building Transmission Loss and Delay Spread at 2.5 GHz

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
L. H. Gonsioroski ◽  
L. da Silva Mello
Keyword(s):  
Transmission Loss ◽  
Signal Transmission ◽  
Delay Spread ◽  
Dispersion Parameters ◽  
Rms Delay Spread ◽  
Urban Buildings ◽  
Time Dispersion ◽  
The Mean ◽  
Mean Excess Delay

This paper presents the results of measurements of signal transmission loss at 2.5 GHz through 10 urban buildings. This allows the characterization of different types of buildings by effective attenuation constants and consideration of the contribution of the transmitted signal in microcell coverage predictions. Power delay profiles (PDPs) of the received signal were also measured and used to determine the time dispersion parameters of the channel, including the mean excess delay and the rms delay spread.

scholarly journals Real-time experimental demonstration of
low-cost VCSEL intensity-modulated 1125Gb/s optical OFDM signal transmission over 25km PON systems

2011 ◽  
Vol 19 (4) ◽  
pp. 2979 ◽  
Author(s):  
E. Hugues-Salas ◽  
R.P. Giddings ◽  
X.Q. Jin ◽  
J. L. Wei ◽  
X. Zheng ◽  
...  
Keyword(s):  
Real Time ◽  
Low Cost ◽  
Signal Transmission ◽  
Experimental Demonstration ◽  
Intensity Modulated ◽  
Ofdm Signal ◽  
Optical Ofdm

scholarly journals Hybrid Composite Laminates from UPE/ESOA Blend Reinforced with Chitosan and Bamboo Fiber: A Study of Mechanical and Thermal Properties

2020 ◽  
Vol 32 (6) ◽  
pp. 1321-1328
Author(s):  
Priyabrata Mohanty ◽  
Dibakar Behera ◽  
Shiv kumari Panda ◽  
Tapan Kumar Bastia ◽  
Prasanta Rath
Keyword(s):  
Composite Laminates ◽  
Unsaturated Polyester ◽  
Low Cost ◽  
Polymer Network ◽  
Filler Concentration ◽  
Mechanical And Thermal Properties ◽  
Thermosetting Polymers ◽  
Low Cost Housing ◽  
Enhanced Properties ◽  
Reinforcing Filler

The development of an inter-cross-linked polymer network of thermoset-thermoset blends have been extensively studied due to their enhanced mechanical properties. Among various polymer blends, modifications of unsaturated polyester (UPE) resin with epoxidized soybean oil acrylate (ESOA) combinations are an attractive route to promote the performance of the thermoset matrix and to overcome the inferior properties of both the components. Biodegradable and effectively accessible chitosan biodegradable waste material can shape the new stage for cutting-edge innovation items. Blend of both recyclable fibrous reinforcement and eco-friendly filler with two miscible thermosetting polymers will provide enhanced properties. At this time, chitosan up to 15 wt% (based on matrix weight) was utilized as reinforcing filler. At last, an interesting result was built up by confirming that chitosan filled chemically tailored bamboo and UPE/ESOA (80:20) biocomposites offered enhanced properties by 10 wt% of filler concentration with the most enhancements in whole properties. They have extensive variety of applications in the sector of low cost housing, structural projects and structural laminates.

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