scholarly journals Enhanced Thermoelectric Performance of n-Type Bi2Se3 Nanosheets through Sn Doping

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1827
Author(s):  
Mengyao Li ◽  
Yu Zhang ◽  
Ting Zhang ◽  
Yong Zuo ◽  
Ke Xiao ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Cost Effective ◽  
Low Grade ◽  
Hot Press ◽  
Processing Technologies ◽  
Sn Doping ◽  
Practical Applications ◽  
Alternative Materials ◽  
The Cost ◽  
Low Grade Heat

The cost-effective conversion of low-grade heat into electricity using thermoelectric devices requires developing alternative materials and material processing technologies able to reduce the currently high device manufacturing costs. In this direction, thermoelectric materials that do not rely on rare or toxic elements such as tellurium or lead need to be produced using high-throughput technologies not involving high temperatures and long processes. Bi2Se3 is an obvious possible Te-free alternative to Bi2Te3 for ambient temperature thermoelectric applications, but its performance is still low for practical applications, and additional efforts toward finding proper dopants are required. Here, we report a scalable method to produce Bi2Se3 nanosheets at low synthesis temperatures. We studied the influence of different dopants on the thermoelectric properties of this material. Among the elements tested, we demonstrated that Sn doping resulted in the best performance. Sn incorporation resulted in a significant improvement to the Bi2Se3 Seebeck coefficient and a reduction in the thermal conductivity in the direction of the hot-press axis, resulting in an overall 60% improvement in the thermoelectric figure of merit of Bi2Se3.

Approaches to the Design and Processing of Novel Titanium Alloys

2007 ◽  
Vol 29-30 ◽  
pp. 127-130
Author(s):  
Colleen J. Bettles ◽  
Rimma Lapovok ◽  
H.P. Ng ◽  
Dacian Tomus ◽  
Barry C. Muddle
Keyword(s):  
Titanium Alloys ◽  
High Performance ◽  
Powder Processing ◽  
Low Cost ◽  
Cost Effective ◽  
Processing Technologies ◽  
Shape Processing ◽  
New Processing ◽  
The Cost ◽  
Processing Techniques

The range of commercial titanium alloys available is currently extremely restricted, with one alloy (Ti-6Al-4V), and derivatives of it, accounting for a very large proportion of all applications. High performance alloys are costly to fabricate and limited to low-volume applications that can sustain the cost. With the emergence of new processing technologies that promise to reduce significantly the cost of production of titanium metal, especially in powder form, there is an emerging imperative for cost-effective near net shape powder processing techniques to permit the benefit of reduced metal cost to be passed on to higher-volume applications. Equally, there is a need for the design and development of new alloys that are intrinsically low-cost and lend themselves to fabrication by novel cost-effective net shape processing. The approaches that might be used to select, design and process both conventional alloys and novel alloy systems will be reviewed, with a focus on innovation in design of low-cost alloys amenable to new processing paths and increasingly tolerant of variability in composition.

scholarly journals A PRACTICAL HYDROPONIC SYSTEM FOR USE IN PLANT NUTRITION STUDIES

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 670d-670
Author(s):  
Larry S. Kennedy ◽  
William B. Beavers ◽  
Carl E. Sams
Keyword(s):  
Distribution System ◽  
Plant Nutrition ◽  
Experimental System ◽  
Cost Effective ◽  
Nutrient Distribution ◽  
Hydroponic System ◽  
Practical Applications ◽  
Rooting Medium ◽  
Set Up ◽  
The Cost

A common problem of researchers concerned with micronutrient plant nutrition is the development of a reliable and affordable experimental system. If nutrient distribution is uneven or subject to outside contamination, then the time and resources dedicated to a project will have been wasted. We have devised a dependable and cost effective nutrient distribution system which has many practical applications. This design is relatively maintenance free, easily adaptable to existing greenhouse conditions and limits the possibility of outside contamination. Using perlite as the rooting medium, our system is constructed of easily obtainable hardware and mechanical components. The total material cost of our system, which included three nutrient treatments, was approximately $800. This resulted in a conservative estimate of $12.50 per plant in our particular study. However, the cost of a larger experiment would be reduced considerably since additional replications could be added at approximately $2.00 each. The experimental set-up is described along with the initial cost analysis.

Joining Techniques for Novel Metal Polymer Hybrid Heat Exchangers

2019 ◽  
Author(s):  
Gowtham Kuntumalla ◽  
Yuquan Meng ◽  
Manjunath Rajagopal ◽  
Ricardo Toro ◽  
Hanyang Zhao ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Waste Heat ◽  
Cost Effective ◽  
The United States ◽  
Thermomechanical Properties ◽  
Low Grade ◽  
Ongoing Work ◽  
Metal Metal ◽  
Low Grade Heat ◽  
Metal Polymer

Abstract In the United States, over 50% of the unrecovered energy from industrial processes is in the form of low-grade heat (< 220°C). Materials and maintenance costs of common heat exchangers are typically too high to justify their usage. Polymers, though more affordable, are usually unsuitable for HX applications due to their low thermal conductivity (∼0.2 W/mK). Here, we show that metal-polymer hybrids may be attractive from both performance and cost perspectives. The use of polymers further increases the resistance to corrosion by sulfuric and carbonic acids often present in flue gases. An ongoing work explores different configurations of layered polyimide-copper macroscale hybrids for heat exchanger applications using numerical simulations. This paper explores a manufacturing pathway for producing such layered hybrid tubes that involves directly rolling and bonding tapes made of polymer and copper foil into tubes. A critical problem in the fabrication process is the bonding of metal and polymers. We explore approaches involving adhesives (epoxy, acrylic and silicone) for metal/polymer interfaces and direct welding (ultrasonic) for metal/metal interfaces that can be integrated into the manufacturing process. We report characterizations of the thermomechanical properties of these joining processes. This work paves the way for realizing cost-effective manufacturing of heat exchangers for low grade waste heat recovery.

Cost Effective Small Scale ORC Systems for Power Recovery From Low Grade Heat Sources

2006 ◽  
Author(s):  
H. Leibowitz ◽  
I. K. Smith ◽  
N. Stosic
Keyword(s):  
Organic Rankine Cycle ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Small Scale ◽  
Low Grade ◽  
Full Potential ◽  
Heat Sources ◽  
Capacity Cost ◽  
Power Recovery ◽  
Low Grade Heat

The growing need to recover power from low grade heat sources, has led to a review of the possibilities for producing systems for cost effective power production at outputs as little as 20-50kWe. It is shown that by utilizing the full potential of screw expanders instead of turbines, it is possible to produce Organic Rankine Cycle (ORC) systems at these outputs, which can be installed for a cost in the range of $1500 to $2000 /kWe of net output. This low capacity cost combined with the ORC's fuel-free specification results in a very favorable value proposition.

Thermosensitive crystallization–boosted liquid thermocells for low-grade heat harvesting

Science ◽  
2020 ◽  
Vol 370 (6514) ◽  
pp. 342-346 ◽  
Author(s):  
Boyang Yu ◽  
Jiangjiang Duan ◽  
Hengjiang Cong ◽  
Wenke Xie ◽  
Rong Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Concentration Gradient ◽  
Relative Efficiency ◽  
Room Temperature ◽  
Cost Effective ◽  
Heat Energy ◽  
Thermoelectric Device ◽  
Low Grade ◽  
Low Grade Heat

Low-grade heat (below 373 kelvin) is abundant and ubiquitous but is mostly wasted because present recovery technologies are not cost-effective. The liquid-state thermocell (LTC), an inexpensive and scalable thermoelectric device, may be commercially viable for harvesting low-grade heat energy if its Carnot-relative efficiency (ηr) reaches ~5%, which is a challenging metric to achieve experimentally. We used a thermosensitive crystallization and dissolution process to induce a persistent concentration gradient of redox ions, a highly enhanced Seebeck coefficient (~3.73 millivolts per kelvin), and suppressed thermal conductivity in LTCs. As a result, we achieved a high ηr of 11.1% for LTCs near room temperature. Our device demonstration offers promise for cost-effective low-grade heat harvesting.

scholarly journals Prospects of Trilateral Flash Cycle (TFC) for Power Generation from Low Grade Heat Sources

2018 ◽  
Vol 64 ◽  
pp. 06004 ◽  
Author(s):  
Iqbal Md Arbab ◽  
Rana Sohel ◽  
Ahmadi Mahdi ◽  
Close Thomas ◽  
Date Abhijit ◽  
...  
Keyword(s):  
Power Generation ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Low Grade ◽  
Power Stations ◽  
Expansion Stage ◽  
Low Grade Heat

Despite the current energy crisis, a large amount of low grade heat (below 100oC) is being wasted for the lack of cost effective energy conversion technology. In the case of the conventional Organic Rankine Cycle (ORC) based geothermal power stations, only about 20% of available heat can be utilised due to a technological limitation as there is a phase change in the working fluid involved during the addition of heat which decreases utilisation effectiveness of the system. Therefore, in this paper, a trilateral flash cycle (TFC) based system has been studied to find out its prospect for utilizing more power from the same heat resources as the ORC. The TFC is a thermodynamic cycle that heats the working fluid as a saturated liquid from which it starts its expansion stage. The flash expansion is achieved by feeding the saturated high-pressured liquid working fluid through a convergent-divergent nozzle at which point it undergoes a flash expansion in the low-pressure environment of the generator housing. The momentum of the working fluid is extracted via a Pelton wheel and the cycle is completed with working fluid condensation and pressurisation. The analytical comparative study between the ORC and TFC based system shows that the TFC has about 50% more power generation capability and almost zero contribution on global warming.

scholarly journals A production-recycling-reuse model for plastic beverages bottles

2021 ◽  
Author(s):  
Nouri Dawood Matar
Keyword(s):  
Market Price ◽  
Environmental Damage ◽  
Low Grade ◽  
Total System ◽  
Pet Bottles ◽  
Alternative Materials ◽  
Present Worth ◽  
Polyethylene Terephthalate Bottles ◽  
The Cost ◽  
Varying Demand

In this thesis a recycling-reuse model is developed and analyzed. Discarded 2L plastic PET (polyethylene terephthalate) bottles are collected from the market. The non-contaminated PET bottles are either remanufactured or used as regrind mixed with virgin PET to produce new bottles to satisfy varying demand. Contaminated bottles are sold to industries using low grade plastic and only badly contaminated bottles go to landfill. Cost of land use and associated environmental damage is calculated as a present worth and charged to the manufacture. Analyses conducted on this model found that the amount of bottles collected had the largest influence on the outcome of the total system unit time cost. Alternative materials to PET that degrade faster are surveyed and used to demonstrate significant reduction in the cost of landfill disposal. Analysis using a minimal market price for remanufactured and newly produced bottles resulted in profit.

scholarly journals HMD-Based VR Tool for Traffic Psychological Examination: Conceptualization and Design Proposition

2021 ◽  
Vol 11 (19) ◽  
pp. 8832
Author(s):  
Vojtěch Juřík ◽  
Václav Linkov ◽  
Petr Děcký ◽  
Sára Klečková ◽  
Edita Chvojková
Keyword(s):  
Situation Awareness ◽  
Driving Simulator ◽  
Cost Effective ◽  
Special Focus ◽  
Practical Applications ◽  
Psychological Phenomena ◽  
Body Of Knowledge ◽  
Recent Advances ◽  
Psychological Examination ◽  
The Cost

In the present theoretical paper, the current body of knowledge regarding the use of wearable virtual reality (VR) technologies for traffic psychological examination (TPE) is introduced, critically discussed and a specific application is suggested. The combination of wearable head-mounted displays for VR with an interactive and cost-effective haptic driving interface is emphasized as a valid and viable platform for a driving skills psychological assessment, which is in several aspects superior to standard TPE as well as driving simulators. For this purpose, existing psychological examination methods and psychological phenomena relevant in the process of driving are discussed together with VR technology’s properties and options. Special focus is dedicated to situation awareness as a crucial, but currently hardly measurable construct, where VR in combination with embedded eye-tracking (ET) technology represents a promising solution. Furthermore, the suitability and possibilities of these VR tools for valid traffic psychological examination are analyzed and discussed. Additionally, potentially desirable measures for driving assessment based on recent advances of VR are outlined and practical applications are suggested. The aim of this article is to bring together recent advances in TPE, VR and ET; revise previous relevant studies in the field; and to propose concept of the cost effective, mobile and expandable HMD-based driving simulator, which can be suitable for an ecologically valid driving assessment and follow-up TPE in common practice.

scholarly journals A production-recycling-reuse model for plastic beverages bottles

2021 ◽  
Author(s):  
Nouri Dawood Matar
Keyword(s):  
Market Price ◽  
Environmental Damage ◽  
Low Grade ◽  
Total System ◽  
Pet Bottles ◽  
Alternative Materials ◽  
Present Worth ◽  
Polyethylene Terephthalate Bottles ◽  
The Cost ◽  
Varying Demand

In this thesis a recycling-reuse model is developed and analyzed. Discarded 2L plastic PET (polyethylene terephthalate) bottles are collected from the market. The non-contaminated PET bottles are either remanufactured or used as regrind mixed with virgin PET to produce new bottles to satisfy varying demand. Contaminated bottles are sold to industries using low grade plastic and only badly contaminated bottles go to landfill. Cost of land use and associated environmental damage is calculated as a present worth and charged to the manufacture. Analyses conducted on this model found that the amount of bottles collected had the largest influence on the outcome of the total system unit time cost. Alternative materials to PET that degrade faster are surveyed and used to demonstrate significant reduction in the cost of landfill disposal. Analysis using a minimal market price for remanufactured and newly produced bottles resulted in profit.

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