Latest Publications & Patents on Aerogels and Aerographene

The United States fire classification system, standardized by NFPA 10, categorizes fires into five main classes based on the type of fuel. Class A includes ordinary combustibles like wood and paper. Class B covers flammable liquids and gases. Class C is for fires involving energized electrical equipment. Class D pertains to combustible metals, and Class K is for cooking oils and fats.

Stirling engines are primarily classified into three mechanical configurations. The Alpha type uses two separate power pistons in interconnected hot and cold cylinders. The Beta type features a single cylinder housing both a power piston and a displacer, which shuttles the working gas between the hot and cold ends. The Gamma type is a variation where the power piston is in a separate, parallel cylinder.

The Effectiveness-NTU method is used in heat exchanger analysis when fluid inlet temperatures are known, but outlet temperatures are not. Effectiveness (\(\epsilon\)) is the ratio of actual heat transfer to the maximum possible heat transfer. The Number of Transfer Units (NTU) is a dimensionless measure of the heat exchanger's size, defined as \(NTU = \frac{UA}{C_{min}}\).

Spin coating is a procedure for depositing uniform thin films onto flat substrates. An excess of a coating solution is placed on the substrate, which is then rotated at high speed. Centrifugal force spreads the solution, and solvent evaporation or curing solidifies the film, with the final thickness determined by viscosity, concentration, and spin speed.

The Fill Factor (FF) is a key parameter that determines the quality of a solar cell. It is the ratio of the maximum power a cell can produce (\(P_{max}\)) to the theoretical power if it were an ideal voltage and current source (\(V_{oc} \times I_{sc}\)). A higher fill factor indicates lower parasitic resistance losses and a more 'square' I-V curve.

The Toyota Production System is founded on the complete elimination of waste, categorized into 7 types, 3 main being described here: Muda (non-value-adding work), Muri (overburden), and Mura (unevenness). While Muda is the most commonly discussed, TPS recognizes that Muri and Mura are often the root causes of Muda and must be addressed first to achieve a truly lean system.

Good Manufacturing Practice (GMP) is a system of regulations and guidelines ensuring that pharmaceutical products are consistently produced and controlled according to quality standards. It covers all aspects of production, from the starting materials, premises, and equipment to the training and personal hygiene of staff. GMP is designed to minimize the risks involved in any pharmaceutical production.

Numerical Control (NC) is the automated control of machining tools using a program composed of precisely coded alphanumeric data. This program dictates the tool's path, feed rate, speed, and other operational parameters. Early NC systems utilized punched paper tape as the input medium, marking a significant technological leap from manual control via handwheels or physical templates.

Class D fires involve combustible metals, alloys, or metal compounds, such as magnesium, titanium, sodium, and lithium. These fires are exceptionally hazardous as they burn at extremely high temperatures and can react explosively with common extinguishing agents like water or carbon dioxide. Water, for instance, in some cases, in contrary to popular believes, can dissociate into hydrogen and oxygen, fueling the fire. Specialized dry powder agents are required for extinguishment.

ANFO (Ammonium Nitrate/Fuel Oil) is a widely used bulk industrial explosive. It consists of a simple mixture of porous ammonium nitrate (AN) prills, which act as the oxidizer, and a fuel oil (FO), typically diesel, which is the fuel. ANFO is classified as a blasting agent due to its relative insensitivity, requiring a booster charge to detonate. Its low cost makes it dominant in mining and construction.

A matrix method of structural analysis fundamental to the finite element method (FEM). It models a structure as an assembly of elements connected at nodes. The method relates nodal forces \({R}\) to nodal displacements \({D}\) through a global stiffness matrix \([K]\), expressed as \([K]{D} = {R}\). Solving this system of linear equations yields the unknown nodal displacements.

A structured methodology for creating new products, typically involving analysis, concept development, and synthesis. It is an iterative cycle where designers research user needs, brainstorm ideas, create prototypes, and test them to refine the final product. This process ensures that the end product is both functional and meets market demands effectively before full-scale production.

Heijunka is the principle of production leveling or smoothing within the Toyota Production System. It involves averaging out the production volume and mix over a fixed period to eliminate peaks and valleys in workload. This creates a predictable and stable manufacturing environment, which is a prerequisite for implementing Just-in-Time (JIT) and standardized work effectively.

Takt time is a theoretical calculation representing the pace of customer demand (\(Available Time \div Demand\)). In contrast, cycle time is an empirical measurement of the actual time taken to complete one unit of work at a specific process step. A core principle of lean manufacturing is to ensure that cycle time is consistently less than or equal to Takt time.

Chemical Vapor Deposition (CVD) is a coating process where a substrate is exposed to one or more volatile chemical precursors. These precursors react or decompose on the substrate's surface in a reaction chamber, producing a high-purity, high-performance solid thin film or coating. Temperature and pressure are critical process parameters that control the deposition rate and film quality.