Materials & Coatings

Catalyst for Carbon Monoxide Oxidation

This catalyst forms carbon dioxide in a high-powered, pulsed CO2 laser.

In many applications, it is highly desirable to operate a CO2 laser in a sealed condition, for in an open system the laser requires a continuous flow of laser gas to remove the dissociation products that occur in the discharge zone of the laser, in order to maintain a stable power output. This adds to the operating cost of the laser, and in airborne or space applications, it also adds to the weight penalty of the laser. In a sealed CO2 laser, a small amount of CO2 gas is decomposed in the electrical discharge zone into corresponding quantities of CO and O2. As the laser continues to operate, the concentration of CO2 decreases, while the concentrations of CO and O2 correspondingly increase. The increasing concentration of O2 reduces laser power, because O2 scavenges electrons in the electrical discharge, thereby causing arcing in the electric discharge and a loss of the energetic electrons required to boost CO2 molecules to lasing energy levels. As a result, laser power decreases rapidly.

Posted in: Briefs, TSP, Materials, Lasers, Carbon monoxide, Catalysts

Titanium Hydroxide — a Volatile Species at High Temperature

Titanium hydroxide, TiO(OH)2 (g), has been identified as the primary reaction product of TiO2    (s) + H2O (g) at high temperatures (1,200–1,400 °C) through the use of the transpiration technique. This technique is a well-established method used to measure equilibrium pressures at 1 atm. Reactive O2 /H2O mixtures of gases flow over the sample, and react to form volatile Ti hydroxides. The collected reaction gas condensate is analyzed to determine the vapor and dissociation pressures. From the amount of condensate and its relation to the partial pressures of the reactive gases, the identity of the volatile hydroxide can be determined. From the relation of product pressure to temperature, thermodynamic enthalpy and entropy of formation can be calculated.

Posted in: Briefs, TSP, Materials, Water, Oxygen, Titanium, Test procedures

Zinc-Doped Tricalcium Phosphate Ceramic for Surgical Implants

This material exhibits an osteogenesis-promoting effect without toxicity, making it suitable as a surgical implant.

A ceramic body consisting of the phases of tricalcium phosphate and/or hydroxyapatite provides biocompatibility with hard tissues. When such a ceramic body is implanted in a bone, direct connection is formed between the bone and the ceramic body without intervention of any fibrous connective tissues. This zinc-containing or zinc-doped ceramic material mainly consists of tricalcium phosphate and is suitable as a ceramic material for biomedical use. In particular, the material provides surgical implant materials for hard tissue consisting of zinc-doped tricalcium phosphate to promote bone formation by releasing zinc in the body.

Posted in: Briefs, MDB, Briefs, Coatings & Adhesives, Materials, Bio-Medical, Implants & Prosthetics, Medical, Prostheses and implants, Biomaterials, Calcium, Ceramics, Materials properties, Zinc alloys

Neuroprosthetics and Solutions for Restoring Sensorimotor Functions

A new class of prosthetic devices looks, feels, and functions like natural limbs.

Advances in body armor and life-saving technology have increased survival rates of severely injured military personnel. Unfortunately, the survivors of improvised explosive devices are often left with amputations and/or spinal cord injuries. The increase in amputations and paralysis among military personnel requires significant advances in prosthetics and functional electrical stimulation (FES) systems so that the soldiers can return to the field or to productive civilian lives.

Posted in: Briefs, MDB, TSP, Briefs, TSP, Coatings & Adhesives, Materials, Bio-Medical, Implants & Prosthetics, Medical

Biotic-Abiotic Interface Between the Body and an Artificial Limb

A modified titanium construct and specially machined surface increase adherence of tissue to a prosthetic limb.

Because of its high mechanical properties, chemical stability, and biocompatibility, titanium is a commonly used material in dental and orthopedic applications. Its excellent biocompatibility allows titanium implants to be directly anchored to bone, or osseo-integrated. The conventional prosthetic replacement in amputees is a stump-socket design, which transfers forces through the prosthetic to an external contact point on the patient. Such a design results in non-uniform distribution of pressure, and can lead to pain, infection, and necrosis of the soft tissues at the point of contact.

Posted in: MDB, Briefs, TSP, Coatings & Adhesives, Materials, Bio-Medical, Implants & Prosthetics, Medical, Prostheses and implants, Materials properties, Titanium, Biomechanics

Optimizing a Laser Process for Making Carbon Nanotubes

Trends in process parameters for optimization and scale-up have been identified.

A systematic experimental study has been performed to determine the effects of each of the operating conditions in a double-pulse laser ablation process that is used to produce single-wall carbon nanotubes (SWCNTs). The comprehensive data compiled in this study have been analyzed to recommend conditions for optimizing the process and scaling up the process for mass production.

Posted in: Briefs, TSP, Materials, Optimization, Lasers, Fabrication, Production engineering, Nanomaterials

Thermogravimetric Analysis of Single-Wall Carbon Nanotubes

 An improved protocol yields greater consistency.

An improved protocol for thermo-gravimetric analysis (TGA) of samples of single-wall carbon nanotube (SWCNT) material has been developed to increase the degree of consistency among results so that meaningful comparisons can be made among different samples. This improved TGA protocol is suitable for incorporation into the protocol for characterization of carbon nanotube material as described in the preceding article.

Posted in: Briefs, TSP, Materials, Materials properties, Nanomaterials, Test procedures, Thermal testing

Particle Distribution on Webs or Cloths

This technology provides the ability to uniformly distribute and attach particulate matter onto fibrous composite sheet or web materials.

This technology provides a methodology and products that are formed from fibrous substrates or film-like surfaces by uniform impregnation with a particulate that is subsequently firmly attached. The extremely uniform distribution of the particulate is accomplished by 1) electrically charging a fibrous matrix with individual exposed surfaces to create a uniform distribution of charged sites; 2) applying particulates to this matrix so that particulates adhere at the charged sites; and 3) the particulates are attached to the individual fibers within the substrate by firm non-transient bonding.

Posted in: Briefs, MDB, Briefs, Manufacturing & Prototyping, Coatings & Adhesives, Materials, Bio-Medical, Medical, Medical equipment and supplies, Fabrics, Fibers, Materials properties

Hollow Radiopaque Bioactive Microspheres Carry Drugs in Embolization Procedures

Combining embolization therapy with localized drug delivery, application of biomaterials is more effective.

The number of applications of synthetic biomaterials continues to expand. However, the imaging of injected biomaterials is important to control the treatment procedure in real time, to avoid complications, and to assess therapeutic success. Embolization is the obstruction of the blood flow in a vessel that can be an effective treatment for tumors in hepatocellular carcinoma or for uterine fibroids. By combining this embolization therapy with a localized drug delivery, the treatment can even be more effective. The material that is currently used is not radiopaque and can therefore cause difficulties for the interventional radiologist during placement of the embolic. Therefore, hollow, drug-carrying microspheres were made radiopaque.

Posted in: Briefs, MDB, Briefs, Coatings & Adhesives, Materials, Bio-Medical, Drug Delivery, Medical, Diseases, Biomaterials, Pharmaceuticals, Polymers

Liquid Cooling/Warming Garment

This lightweight garment can be used by firefighters, soldiers, and personnel working with hazardous materials.

The NASA liquid cooling/ventilating garment (LCVG) currently in use was developed over 40 years ago. With the commencement of a greater number of extra-vehicular activity (EVA) procedures with the construction of the International Space Station, problems of astronaut comfort, as well as the reduction of the consumption of energy, became more salient.

Posted in: Briefs, MDB, Briefs, Coatings & Adhesives, Materials, Bio-Medical, Medical, Patient Monitoring, Human factors, Spacesuits

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