Online monitoring of coffee roasting by proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS): towards a real-time process control for a consistent roast profile

A real-time automated process control tool for coffee roasting is presented to consistently and accurately achieve a targeted roast degree. It is based on the online monitoring of volatile organic compounds (VOC) in the off-gas of a drum roaster by proton transfer reaction time-of-flight mass spectrometry at a high time (1 Hz) and mass resolution (5,500 m/Δm at full width at half-maximum) and high sensitivity (better than parts per billion by volume). Forty-two roasting experiments were performed with the drum roaster being operated either on a low, medium or high hot-air inlet temperature (= energy input) and the coffee (Arabica from Antigua, Guatemala) being roasted to low, medium or dark roast degrees. A principal component analysis (PCA) discriminated, for each one of the three hot-air inlet temperatures, the roast degree with a resolution of better than ±1 Colorette. The 3D space of the three first principal components was defined based on 23 mass spectral profiles of VOCs and their roast degree at the end point of roasting. This provided a very detailed picture of the evolution of the roasting process and allowed establishment of a predictive model that projects the online-monitored VOC profile of the roaster off-gas in real time onto the PCA space defined by the calibration process and, ultimately, to control the coffee roasting process so as to achieve a target roast degree and a consistent roasting.     

The Role of the Cricothyroid Joint Anatomy in Cricothyroid Approximation Surgery

Objectives/Hypothesis

Cricothyroid approximation (CTA) surgery aims at raising the voice pitch in male-to-female transsexuals. However, 30% of the patients are not satisfied with the result. The purpose of our study was to examine the cricothyroid joint (CTJ) biomechanics and to analyze if (and how) the CTJ anatomy influences the movement of the cricoid and, consequently, the elongation of the vocal fold and the voice pitch after CTA.

Methods

Twenty-four cadaver larynges were examined with high-resolution computerized tomography and MIMICS three-dimensional imaging software (Materialise Interactive Medical Image Control System, Leuven, Belgium). After superimposing the two scans taken in “neutral” and in “CTA” positions, vector geometrical analysis was used to determine the effective rotation axis of the CTJ and to calculate the elongation of the vocal folds after CTA.

Results

Our results showed that the cricoid rotates around an axis, the position of which depends on the anatomical structure of the CTJ. Based on the location of this effective rotation axis, we could distinguish three groups. In group I (N = 13), the rotation axis was located in the lower third; in group II (N = 5), it was located in the middle third; and in group III (N = 6), it was located in the upper third of the cricoid. The elongations of the vocal fold were 12%, 8%, and 3%, in groups I, II, and III, respectively.

Conclusions

The anatomical structure of the CTJ influences directly (1) the position of the effective rotation axis and (2) the elongation of the vocal folds.     

Widely tunable, nondegenerate three-wave mixing microwave device operating near the quantum limit

We present the first experimental realization of a widely frequency tunable, nondegenerate three-wave mixing device for quantum signals at gigahertz frequency. It is based on a new superconducting building block consisting of a ring of four Josephson junctions shunted by a cross of four linear inductances. The phase configuration of the ring remains unique over a wide range of magnetic fluxes threading the loop. It is thus possible to vary the inductance of the ring with flux while retaining a strong, dissipation-free, and noiseless nonlinearity. The device has been operated in amplifier mode, and its noise performance has been evaluated by using the noise spectrum emitted by a voltage-biased tunnel junction at finite frequency as a test signal. The unprecedented accuracy with which the crossover between zero-point fluctuations and shot noise has been measured provides an upper bound for the noise and dissipation intrinsic to the device.     

Analysing the isotopic life history of the alpine ungulates Capra ibex and Rupicapra rupicapra rupicapra through their horns

The horn of ungulate grazers offers a valuable isotopic record of their diet and environment. However, there have been no reports of the spatio‐temporal variation of the isotopic composition of horns. We investigated patterns of carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic composition along and perpendicular to the horn axis in Capra ibex and Rupicapra rupicapra rupicapra to assess the effects of animal age, within‐year (seasonal) and inter‐annual variation, natural contamination and sampling position on horn isotope composition. Horns of male C. ibex (n = 23) and R. r. rupicapra (n = 1) were sampled longitudinally on the front (only R. r. rupicapra) and back side and on the surface and sub‐surface. The sides of the R. r. rupicapra horn did not differ in δ¹³C. In both species, the horn surface had a 0.15‰ lower δ¹³C and a higher carbon‐to‐nitrogen (C/N) ratio than the sub‐surface. Washing the horn with water and organic solvents removed material that caused these differences. With age, the δ¹⁵N of C. ibex horns increased (+0.1‰ year^?1), C/N ratio increased, and ¹³C discrimination relative to atmospheric CO₂ (¹³Δ) increased slightly (+0.03‰ year^?1). Geostatistical analysis of one C. ibex horn revealed systematic patterns of inter‐annual and seasonal ¹³C changes, but ¹⁵N changed only seasonally. The work demonstrates that isotopic signals in horns are influenced by natural contamination (δ¹³C), age effects (¹³Δ and δ¹⁵N), and seasonal (δ¹³C and δ¹⁵N) and inter‐annual variation (δ¹³C). The methods presented allow us to distinguish between these effects and thus allow the use of horns as isotopic archives of the ecology of these species and their habitat. Copyright © 2009 John Wiley & Sons, Ltd.     

High-speed photorefraction at telecommunication wavelength 1.55 microm in Sn2P2S6:Te

We demonstrated for what is the first time to our knowledge photorefractive two-wave mixing in a bulk ferroelectric crystal using cw light at the telecommunication wavelength 1.55 microm. In the Te-doped ferroelectric semiconductor Sn2P2S6 with absorption constant <0.1 cm(-1) at 1.55 microm, grating recording times of 10 ms and a two-beam coupling gain of 2.8 cm(-1) have been measured at 350 mW power (intensity 440 W/cm(2)) without a necessity to apply an external electric field. With a moving grating technique, a maximal gain of 6.0 cm(-1) has been obtained.     

Solid dispersion systems engineered from hydroxypropyl‐β‐cyclodextrin and water‐soluble polymers for enhanced oral bioavailability of nimodipine

Nimodipine (NMD) is a calcium channel blocker that is used in the treatment of cerebrovascular disorders, such as stroke indicated for biological rhythm and neurological disorders. According to biopharmaceutical classification, NMD is categorized as a class ΙΙ drug, meaning it has a poor solubility profile. The objective of this experiment is to prepare multicomponent systems to enhance the solubility, dissolution, and bioavailability of NMD. Inclusion complex and solvent evaporation techniques have been exploited to overcome this challenge. in vitro dissolution studies and solubility, the profile was performed in three pH media (pH 7.5, 1.2, and 6.8). The drug release at (Q_60min) for SD‐PVP3 was 33‐fold higher than pure NMD in double‐distilled water. The solubility of SD PVP3 was about 30 times higher than plain NMD in double‐distilled water. A pharmacokinetic study in rats indicated that the AUC_0‐720 value of the inclusion complex (NMD‐KD) was 1.63‐fold higher than pure NMD. At the same time, the solid dispersion (NMD‐SD PVP3) was 3.94‐fold higher than that of plain NMD, indicating a significant increase in the bioavailability of NMD. The combination of the inclusion complex and solvent evaporation method led to the formation of new solid dispersions (SD PLX and SD PVP), which significantly increased the solubility, dissolution, and the oral bioavailability of NMD.