Bradley James Ingebrethsen

Bio: Bradley James Ingebrethsen is an academic researcher from R. J. Reynolds Tobacco Company. The author has contributed to research in topics: Particle & Sidestream smoke. The author has an hindex of 7, co-authored 8 publications receiving 907 citations.

Aerosol delivery article

Abstract: An aerosol delivery article is capable of producing substantial quantities of smoke, both initially and over the useful lifetime of the product, without significant thermal degradation of the aerosol former and without the presence of substantial pyrolysis or incomplete combustion products or sidestream smoke. The article also delivers very low levels of carbon monoxide. The article is able of providing the user with the sensations and benefits of cigarette smoking without burning tobacco. The article includes a carbonaceous fuel element (18), an aerosol forming substance within a heat conductive container (26,36), an outer member (14) surrounding the heat conductive container, and a mouthend piece (24). Upon draw on the mouthend piece air enters the peripheral region of the outer member and enters the heat conductive container. As the heat conductive container (26) is in a heat exchange relationship with the fuel element (18), aerosol is thereby formed within the container and passed to the mouth of the user.

Reservoir and heater system for controllable delivery of multiple aerosolizable materials in an electronic smoking article

Abstract: The present disclosure relates to an electronic smoking article that provides for improved aerosol delivery. Particularly, the article provides for separate delivery of two or more components of an aerosol precursor composition to one or more heaters so as to control the rate of delivery or the rate of heating of the separate components of the aerosol precursor composition.

Smoking article with dual burn rate fuel element

Abstract: The present invention preferably relates to a smoking article which is capable of producing substantial quantities of aerosol, both initially and over the useful life of the product, without significant thermal degradation of the aerosol former and without the presence of substantial pyrolysis or incomplete combustion products or sidestream aerosol. The article employes a dual burn rate fuel element, which utilizes a fast burning segment (10B) and a slow burning segment (10A). The use of such a dual burn rate fuel element has several advantages over conventional homogeneous fuels. For example, the fast burning component assists in the ease of lighting the fuel element, and provides rapid heat transfer to the aerosol generating means (14). This in turn, provides early aerosol delivery. The slow burning component provides for even heat distribution throughout the burn period. The slow burning material ensures steady aerosol delivery in terms of amount and provides adequate fuel for simulating the number of puffs obtained from a conventional cigarette, i.e., about nine or ten, when smoked under standard FTC conditions.

Evolution of the Particle Size Distribution of Mainstream Cigarette Smoke During a Puff

Abstract: A procedure for the measurement of the particle size distribution of minimally aged undiluted mainstream cigarette smoke is presented. The angular dependence of scattered light intensity was measured and a best fit log normal distribution was determined by comparison of ratios of the scattering intensities to theoretically calculated values. The problem of multiple scattering by the concentrated mainstream smoke was overcome by aerodynamically focusing the sampled smoke to a fine stream in a specially designed photometer. The photometer required no dilution of the smoke and performed the measurement on smoke aged 0.12 s, minimizing coagulation. Size distributions were determined at 100 points during a 2-s puff revealing significant changes in the average diameter of the aerosol during the puff. The changes in particle size are shown to correlate with the changing flow profiles in the cigarette during the smoking process.

A repeatable method for determination of carboxyhemoglobin levels in smokers.

Abstract: Fourteen male smokers participated in ten afternoon test sessions to determine the daily variation in expired breath carbon monoxide (CO), and whole blood percent carboxyhemoglobin (%COHb), hemoglobin and hematocrit levels. Each individual's test session was conducted at approximately the same time of day to estimate CO-related measures under relatively stable conditions. Subjects smoked ad libitum prior to testing. The 'usual brand' cigarette was smoked during the first measurement week (sessions 1-5 held on Monday through Friday) and a research cigarette prototype which primarily heats rather than burns tobacco (TOB-HT) was smoked by 12 of the 14 subjects for 3 weeks prior to and during the second measurement week (sessions 6-9 held on Tuesday through Friday). Following the last 'usual brand' measurement session, subjects completed 21 days of ad libitum smoking of the TOB-HT cigarette before starting sessions 6-9 to allow acclimation to the TOB-HT research cigarette. Following session 9, 11 of the 14 subjects continued to smoke the TOB-HT cigarette for an additional 3 weeks and then participated in an additional test session (session 10). The data indicate that daily measurements of afternoon %COHb and expired breath CO values for an individual are reproducible when using this protocol. Carboxyhemoglobin and expired breath CO levels were elevated by 24.4 and 30.6%, respectively, after switching to the TOB-HT cigarette. This increase was not due to an increase in the number of cigarettes consumed since the subjects smoked an average of 21 cigarettes prior to the measurement session when smoking either their 'usual brand' or the TOB-HT cigarette.

Tobacco-containing smoking article

Abstract: A smoking article may include a cigarette incorporated within an electrically powered aerosol generating device that acts as a holder for that cigarette. The smoking article possesses at least one form of tobacco. The smoking article also possesses a mouth-end piece that is used by the smoker to inhale components of tobacco that are generated by the action of heat upon components of the cigarette. A representative smoking article possesses an outer housing incorporating a source of electrical power (e.g., a battery), a sensing mechanism for powering the device at least during periods of draw, and a heating device (e.g., at least one electrical resistance heating element) for forming a thermally generated aerosol that incorporates components of tobacco. During use, the cigarette is positioned within the device, and after use, the used cigarette is removed from the device and replaced with another cigarette.

Electronic smoking article

Abstract: An electronic smoking article comprising an aerosol generator and a mechanical aerosol converter insert having the capacity to improve characteristics of aerosol produced by the aerosol generator, including sensory attributes.

Light scattering by particles: Computational methods

Abstract: This book presents the separation-of-variables and T-matrix methods of calculating the scattering of electromagnetic waves by particles. Analytical details and computer programs are provided for determining the scattering and absorption characteristics of the finite-thickness slab, infinite circular cylinder (normal incidence), general axisymmetric particle, and sphere.The computer programs are designed to generate data that is easy to graph and visualize, and test cases in the book illustrate the capabilities of the programs. The connection between the theory and the computer programs is reinforced by references in the computer programs to equations in the text. This cross-referencing will help the reader understand the computer programs, and, if necessary, modify them for other purposes.

Electronic smoking device

Abstract: An electronic smoking device includes a first sensor for detecting a users action for smoking, an air inlet, an air flow path extending from the air inlet, a liquid compartment storing a smoking liquid, a dispensing control device configured to selectively dispense the smoking liquid from the liquid compartment, a vaporizing compartment connected to the liquid compartment and the air flow path, a heater located at the vaporizing compartment, a controller configured to activate the heater to vaporize the smoking liquid dispensed from the liquid compartment when the user's action for smoking is detected by the first sensor, and a smoke outlet connected to the vaporizing compartment, wherein an amount of the smoking liquid dispensed by the dispensing control device is responsive to an amount of air flowing in the vaporizing compartment.

Aerosol electronic cigarette

Abstract: An aerosol electronic cigarette includes a battery assembly, an atomizer assembly and a cigarette bottle assembly and also includes a shell (a) which is hollow and integrally formed. Said battery assembly connects with said atomizer assembly and both are located in said shell (a). Said cigarette bottle assembly is located in one end of the shell (a), which is detachable. Said cigarette bottle assembly fits with said atomizer assembly. Said shell (a) has through-air-inlets (a 1 ).