Improving Refractories for Waste to Energy Challenges

2011 ◽  
Author(s):  
Patrick M. Stephan ◽  
William H. Burak
Keyword(s):  
Water Content ◽  
Narrow Range ◽  
Operating Conditions ◽  
Waste To Energy ◽  
Energy Market ◽  
Thermal Gradients ◽  
Wide Range ◽  
Refractory Life ◽  
Materials Used ◽  
Harmful Effects

Operating conditions in steam generating units (boilers) in the waste-to-energy market present a wide range of operating conditions which challenge materials used throughout the units. While operators attempt to operate within a narrow range of conditions, the variability of fuel types, heating values and water content specifically affect refractory life throughout the units. In recent years, many operators have modified combustion conditions in order to reduce controlled emissions, resulting in higher temperatures, larger thermal gradients and different gas chemistries, with potentially harmful effects on refractory performance. Refractory manufacturers have responded through material developments and installation improvements which are meeting the new operating challenges.

scholarly journals Pembuatan Serbuk Aloe Vera sebagai Bahan Baku Kosmetik Masker Wajah Menggunakan Metode Vacuum Drying

2019 ◽  
Vol 3 (2) ◽  
pp. 62
Author(s):  
Ayu Ratna Permanasari ◽  
Saripudin Saripudin ◽  
Tri Reksa Saputra ◽  
Muhammad Fahmi Hidayatulloh ◽  
Nizar Fathurohman
Keyword(s):  
Water Content ◽  
Operating Temperature ◽  
Aloe Vera ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Vacuum Drying ◽  
Drying Process ◽  
Cosmetic Industry ◽  
Materials Used ◽  
Measured Water

Serbuk lidah buaya merupakan salah satu produk olahan lidah buaya yang banyak digunakan industri kosmetik sebagai bahan tambahan. Tujuan dari penelitian ini adalah untuk menentukan kondisi operasi dan konsentrasi zat aditif dengan variasi temperatur operasi (50oC, 60oC, dan 70oC) dan variasi konsentrasi maltodekstrin (6%, 7%, 8%, dan 9%) dalam pembuatan serbuk lidah buaya untuk mencapai kandungan antrakuinon terendah dan kandungan glukomanan tertinggi. Bahan yang digunakan adalah lidah buaya (Aloe Vera barbadensis.) yang dilakukan ­perlakuan awal sebelum pengeringan. Serbuk lidah buaya diukur kadar air, rendemen, kandungan antrakuinon dan kandungan glukomanan. Hasil menunjukan bahwa pada temperatur 60oC dan konsentrasi maltodekstrin 8%, serbuk lidah buaya memiliki kadar air 6,92%; rendemen 9% kandungan antrakuinon 20,8%; dan kandungan glukomanan 11,5% merupakan hasil terbaik.Aloe vera powder is one of processed aloe products are widely used cosmetic industry as an additive. The purpose of this study was to determine the optimum operating conditions and concentrations of additives by variations in the operating temperature (50, 60, and 70°C) and the variation of the concentration of maltodextrin (6, 7, 8, and 9%) in the manufacture of aloe vera powder to reach the lowest anthraquinone content and highest glucomannan content. Materials used are pre treated aloe vera (Aloe Vera barbadensis.) before drying process. Aloe vera powder measured water content, yield, anthraquinone content, and glucomannan content. Results showed that at temperature of 60° C and a concentration of 8%. Aloe vera powder has a water content of 6,92%; 9,00% yield; glucomannan content of 11,50%; and 27.30% anthraquinone content is the best results.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

Research on the Economic Organization Environmental Impact

2017 ◽  
Vol 68 (3) ◽  
pp. 599-601
Author(s):  
Dan Paul Stefanescu ◽  
Oana Roxana Chivu ◽  
Claudiu Babis ◽  
Augustin Semenescu ◽  
Alina Gligor
Keyword(s):  
Economic Activity ◽  
Economic Organization ◽  
Economic Activities ◽  
Environmental Implications ◽  
Minimal Impact ◽  
Wide Range ◽  
Material Environment ◽  
Negative Effect ◽  
Harmful Effects

Any economic activity carried out by an organization, can generate a wide range of environmental implications. Particularly important, must be considered the activities that have a significant negative effect on the environment, meaning those which pollute. Being known the harmful effects of pollution on the human health, the paper presents two models of utmost importance, one of the material environment-economy interactions balance and the other of the material flows between environmental factors and socio-economic activities. The study of these models enable specific conditions that must be satisfied for the economic processes friendly coexist to the environment for long term, meaning to have a minimal impact in that the residues resulting from the economic activity of the organization to be as less harmful to the environment.

Nitrogen Removal from Anaerobically-Treated Leachate

1984 ◽  
Vol 19 (1) ◽  
pp. 87-100
Author(s):  
D. Prasad ◽  
J.G. Henry ◽  
P. Elefsiniotis
Keyword(s):  
Nitrogen Removal ◽  
Air Flow ◽  
Operating Conditions ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Anaerobic Filter ◽  
Ph Values ◽  
Wide Range ◽  
Ammonia Desorption ◽  
Effects Of Ph

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.

Waste to Energy Conversion and Sustainable Recovery of Nutrients from Pee Power - Recent Advancements in Urine-Fed MFCs

2020 ◽  
Vol 17 (7) ◽  
pp. 768-779
Author(s):  
Natarajan Narayanan ◽  
Vasudevan Mangottiri ◽  
Kiruba Narayanan
Keyword(s):  
Power Generation ◽  
Microbial Fuel Cells ◽  
Alternative Energy ◽  
Material Selection ◽  
Waste Product ◽  
Resource Recovery ◽  
Operating Conditions ◽  
Waste To Energy ◽  
Animal Origin ◽  
Human Beings

Microbial Fuel Cells (MFCs) offer a sustainable solution for alternative energy production by employing microorganisms as catalysts for direct conversion of chemical energy of feedstock into electricity. Electricity from urine (urine-tricity) using MFCs is a promising cost-effective technology capable of serving multipurpose benefits - generation of electricity, waste alleviation, resource recovery and disinfection. As an abundant waste product from human and animal origin with high nutritional values, urine is considered to be a potential source for extraction of alternative energy in the coming days. However, developments to improve power generation from urine-fed MFCs at reasonable scales still face many challenges such as non-availability of sustainable materials, cathodic limitations, and low power density. The aim of this paper was to critically evaluate the state-of-the-art research and developments in urine-fed MFCs over the past decade (2008-2018) in terms of their construction (material selection and configuration), modes of operation (batch, continuous, cascade, etc.) and performance (power generation, nutrient recovery and waste treatment). This review identifies the preference for sources of urine for MFC application from human beings, cows and elephants. Among these, human urine-fed MFCs offer a variety of applications to practice in the real-world scenario. One key observation is that, effective disinfection can be achieved by optimizing the operating conditions and MFC configurations without compromising on performance. In essence, this review demarcates the scope of enhancing the reuse potential of urine for renewable energy generation and simultaneously achieving resource recovery.

scholarly journals Bio-Based Alternatives to Phenol and Formaldehyde for the Production of Resins

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2237 ◽  
Author(s):  
P. R. Sarika ◽  
Paul Nancarrow ◽  
Abdulrahman Khansaheb ◽  
Taleb Ibrahim
Keyword(s):  
Raw Materials ◽  
Phenol Formaldehyde ◽  
Raw Material ◽  
Wood Industry ◽  
Suitable Material ◽  
The Past ◽  
Wide Range ◽  
Recent Developments ◽  
Sustainable Materials ◽  
Materials Used

Phenol–formaldehyde (PF) resin continues to dominate the resin industry more than 100 years after its first synthesis. Its versatile properties such as thermal stability, chemical resistance, fire resistance, and dimensional stability make it a suitable material for a wide range of applications. PF resins have been used in the wood industry as adhesives, in paints and coatings, and in the aerospace, construction, and building industries as composites and foams. Currently, petroleum is the key source of raw materials used in manufacturing PF resin. However, increasing environmental pollution and fossil fuel depletion have driven industries to seek sustainable alternatives to petroleum based raw materials. Over the past decade, researchers have replaced phenol and formaldehyde with sustainable materials such as lignin, tannin, cardanol, hydroxymethylfurfural, and glyoxal to produce bio-based PF resin. Several synthesis modifications are currently under investigation towards improving the properties of bio-based phenolic resin. This review discusses recent developments in the synthesis of PF resins, particularly those created from sustainable raw material substitutes, and modifications applied to the synthetic route in order to improve the mechanical properties.

scholarly journals Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review

2021 ◽  
Vol 13 (15) ◽  
pp. 8620
Author(s):  
Sanaz Salehi ◽  
Kourosh Abdollahi ◽  
Reza Panahi ◽  
Nejat Rahmanian ◽  
Mozaffar Shakeri ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Operating Conditions ◽  
Phenolic Pollutants ◽  
Petroleum Refinery Wastewater ◽  
Start Up ◽  
Low Concentrations ◽  
Effective Removal ◽  
Wide Range ◽  
Loading Effects ◽  
Spent Caustic

Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.

scholarly journals Wide range continuously tunable and fast thermal switching based on compressible graphene composite foams

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tingting Du ◽  
Zixin Xiong ◽  
Luis Delgado ◽  
Weizhi Liao ◽  
Joseph Peoples ◽  
...  
Keyword(s):  
Thermal Management ◽  
Dynamic Control ◽  
Operating Conditions ◽  
Dynamic Thermal Management ◽  
Graphene Composite ◽  
Continuous Tuning ◽  
Composite Foams ◽  
Wide Range ◽  
Thermal Switches ◽  
Thermal Switching

AbstractThermal switches have gained intense interest recently for enabling dynamic thermal management of electronic devices and batteries that need to function at dramatically varied ambient or operating conditions. However, current approaches have limitations such as the lack of continuous tunability, low switching ratio, low speed, and not being scalable. Here, a continuously tunable, wide-range, and fast thermal switching approach is proposed and demonstrated using compressible graphene composite foams. Large (~8x) continuous tuning of the thermal resistance is achieved from the uncompressed to the fully compressed state. Environmental chamber experiments show that our variable thermal resistor can precisely stabilize the operating temperature of a heat generating device while the ambient temperature varies continuously by ~10 °C or the heat generation rate varies by a factor of 2.7. This thermal device is promising for dynamic control of operating temperatures in battery thermal management, space conditioning, vehicle thermal comfort, and thermal energy storage.

scholarly journals Fundamental limits of electron and nuclear spin qubit lifetimes in an isolated self-assembled quantum dot

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
George Gillard ◽  
Ian M. Griffiths ◽  
Gautham Ragunathan ◽  
Ata Ulhaq ◽  
Callum McEwan ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Operating Conditions ◽  
External Control ◽  
Spin Qubits ◽  
Fundamental Limits ◽  
Trade Offs ◽  
Wide Range ◽  
Spin Qubit

AbstractCombining external control with long spin lifetime and coherence is a key challenge for solid state spin qubits. Tunnel coupling with electron Fermi reservoir provides robust charge state control in semiconductor quantum dots, but results in undesired relaxation of electron and nuclear spins through mechanisms that lack complete understanding. Here, we unravel the contributions of tunnelling-assisted and phonon-assisted spin relaxation mechanisms by systematically adjusting the tunnelling coupling in a wide range, including the limit of an isolated quantum dot. These experiments reveal fundamental limits and trade-offs of quantum dot spin dynamics: while reduced tunnelling can be used to achieve electron spin qubit lifetimes exceeding 1 s, the optical spin initialisation fidelity is reduced below 80%, limited by Auger recombination. Comprehensive understanding of electron-nuclear spin relaxation attained here provides a roadmap for design of the optimal operating conditions in quantum dot spin qubits.

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