scholarly journals Difference Spectroscopy in the Analysis of the Effects of Coffee Cherry Processing Variables on the Flavor of Brewed Coffee

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Donald J. Lyman ◽  
Robert M. Benck ◽  
Scott F. Merle
Keyword(s):  
Vinyl Ester ◽  
Difference Spectroscopy ◽  
Aldehyde Ester ◽  
Green Beans ◽  
Difference Spectra ◽  
Paired Samples ◽  
Processing Variables ◽  
Standard Manner ◽  
Ft Ir

Infrared difference spectroscopy was used to study how changes in the processing of Arabica coffee cherries into green beans affected the flavor of coffee brewed from roasted green beans. Paired samples of green beans, in which the drying step or fermentation/washing step in their processing was altered, were roasted and brewed in a standard manner and their ATR-FT-IR spectra obtained. Difference spectra of the 1800 to 1680 cm−1 carbonyl region of water-subtracted spectra of paired samples of these brewed coffees provided data which indicated differences in brewed coffee flavor due to changes in fermentation/washing steps and drying steps involved in the processing of coffee cherries. The role of acid, ketone, aldehyde, ester, lactone, and vinyl ester carbonyl components on the flavor of brewed coffee is proposed that is consistent with the flavors as perceived by the coffee tasters.

Atr/Ft-Ir Difference Spectroscopy of Biological Matter with Microsecond Time Resolution

1996 ◽  
Vol 50 (5) ◽  
pp. 588-596 ◽  
Author(s):  
Joachim Heberle ◽  
Christian Zscherp
Keyword(s):  
Attenuated Total Reflection ◽  
High Temporal Resolution ◽  
Difference Spectroscopy ◽  
Difference Spectra ◽  
Time Resolved ◽  
Precise Control ◽  
Biological Matter ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Atr Spectroscopy

Attenuated total reflection (ATR) spectroscopy allows precise control of external parameters vital for proper functioning of biological matter. For the first time in biospectroscopy, ATR difference spectroscopy has been combined with the step-scan technique. The current setup integrates a broad frequency range (800–25,000 cm−1) with high temporal resolution (5 μs). Vibrations are detected that arise from single amino acids (<10−3 absorbance units) of the chromoprotein bacteriorhodopsin. Time-resolved ATR/FT-IR difference spectra are compared with conventional transmission spectra. The high mirror stability enables time-resolved FT-vis spectroscopy of the same sample with the same instrument. Potential applications even to non-light-absorbing biomaterial are discussed.

scholarly journals Experimental and Theoretical Studies of Sonically Prepared Cu–Y, Cu–USY and Cu–ZSM-5 Catalysts for SCR deNOx

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 824
Author(s):  
Przemysław J. Jodłowski ◽  
Izabela Czekaj ◽  
Patrycja Stachurska ◽  
Łukasz Kuterasiński ◽  
Lucjan Chmielarz ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Ultrasonic Irradiation ◽  
Active Phase ◽  
Spectroscopic Studies ◽  
In Situ Drifts ◽  
Ft Ir ◽  
Diffuse Reflectance Infrared ◽  
Experimental And Theoretical Studies

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).

The role of melatonin on zebrafish follicle development: An FT-IR imaging approach

2012 ◽  
Vol 62 ◽  
pp. 279-285 ◽  
Author(s):  
Elisabetta Giorgini ◽  
Giorgia Gioacchini ◽  
Carla Conti ◽  
Paolo Ferraris ◽  
Simona Sabbatini ◽  
...  
Keyword(s):  
Follicle Development ◽  
Ir Imaging ◽  
Imaging Approach ◽  
Ft Ir

A Simple Dissolved Metals Mixing Route to Prepare Nanostructured Mg0.8Zn0.2TiO3 Solid Solution

2015 ◽  
Vol 1112 ◽  
pp. 47-52 ◽  
Author(s):  
Frida Ulfah Ermawati ◽  
Suasmoro Suasmoro ◽  
Suminar Pratapa
Keyword(s):  
Solid Solution ◽  
Particle Size ◽  
Rietveld Analysis ◽  
Dissolved Metals ◽  
Intermediate Phases ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Zn Ions

A study of liquid mixing route to synthesize high purity Mg0.8Zn0.2TiO3 nanopowder, a candidate dielectric ceramics, has been successfully performed. Formation of the phases on the dried powder was studied using TG/DTA, XRD and FT-IR data. Rietveld analysis on the collected XRD patterns confirmed the formation of solid solution in the system. Such solid solution can be obtained from the powder calcined at 500 °C, but calcination at 550 °C gave rise to the most optimum molar purity up to 98.5% without intermediate phases. The role of Zn ions on the formation of solid solution was also discussed. Homogeneity of particle size distribution and nano-crystallinity of the system was verified from the particle size analyzer data, TEM image and the Rietveld analysis output.

AN INTERACTIONAL APPROACH TO ATTRIBUTIONAL DIMENSIONS IN DYSPHORIA

1990 ◽  
Vol 18 (2) ◽  
pp. 267-277 ◽  
Author(s):  
Janet E. Eschen ◽  
David S. Glenwick
Keyword(s):  
Attributional Style ◽  
The Self ◽  
Regression Analyses ◽  
Self Blame ◽  
Attributional Style Questionnaire ◽  
Standard Manner ◽  
Stability Dimension ◽  
The Stability ◽  
The Relationship

To investigate the possible contributions to dysphoria of interactions among attributional dimensions, 105 freshmen and sophomores were administered the Attributional Style Questionnaire and the Beck Depression Inventory. Analyses examined the relationship to dysphoria of (a) the traditional composite score; (b) multiple regression analyses including interactions among the various dimensions; and (c) indices of behavioral self-blame, characterological self-blame, and external blame. The results provided modest support for the specific hypothesized interactional model and, to a large extent, appeared to support the validity of the standard manner in which dysphoric attributional style is viewed. Refinements of the traditional model are suggested, involving the self-blame construct, the possible role of the stability dimension, and the relationship between controllability and positive event attributions.

Analysis of Noise for Rapid-Scan and Step-Scan Methods of FT-IR Difference Spectroscopy

2001 ◽  
Vol 55 (9) ◽  
pp. 1161-1165 ◽  
Author(s):  
Steven S. Andrews ◽  
Steven G. Boxer
Keyword(s):  
Difference Spectroscopy ◽  
Rapid Scan ◽  
Ft Ir

Effect of Green Microstructure and Processing Variables on the Microwave Sintering of Alumina

1990 ◽  
Vol 189 ◽  
Author(s):  
Arindam Dé ◽  
Iftikhar Ahmad ◽  
E. Dow Whitney ◽  
David E. Clark
Keyword(s):  
Particle Size ◽  
Microwave Sintering ◽  
Heating Rates ◽  
Hybrid Heating ◽  
Processing Variables ◽  
Conventional Sintering ◽  
Rapid Sintering ◽  
Temperature Time ◽  
Fast Firing

ABSTRACTThe concept of 'hybrid heating with microwave (MW) energy at 2.45 GHZ.'for ultra rapid sintering of alumina is being introduced. This technique is a combination of MW - materual interaction as well as conventional radiant/conduction mechanisms, and facilitates the attainment of perhaps, the highest possible heating rates in a multimode MW cavity at 2.45 GJZz. (1500ºC in 120 sees.). Rapid sintering of pure.undoped alumina with this novel techniQue culminates in uniform, homogeneous microstructures and mechanical property enhancements vis-a-vis conventional fast firing.The role of green microstructure (particle size) on MW(hybrid) heating and processing variables (temperature, time) on the MW (hybrid) heating phenomena vs. conventional fast firing were investigated. Hybrid heated samples showed accelerated densification with comparable grain sizes when compared with the conventionally fast fired samples. The effectof particle size on the microwave (hybrid) heating phenomena was found to be analogous to conventional sintering.

Depth Profile Study of Large-Sized Coal Samples by Fourier Transform Infrared Photoacoustic Spectroscopy

1986 ◽  
Vol 40 (2) ◽  
pp. 214-217 ◽  
Author(s):  
Tiziana Zerlia
Keyword(s):  
Fourier Transform ◽  
Depth Profile ◽  
Photoacoustic Spectroscopy ◽  
Modulation Frequency ◽  
Fourier Transform Infrared ◽  
Qualitative Description ◽  
Difference Spectra ◽  
Compositional Depth Profile ◽  
Ft Ir ◽  
Infrared Photoacoustic Spectroscopy

A multidisciplinary approach is demonstrated to elucidate coal weathering at a molecular level. Fourier Transform Infrared Photoacoustic Spectroscopy (FT-IR/PAS) provides a technique for a compositional depth profile of coal by simply varying the modulation frequency (mirror velocity) of the light impinging upon the solid surface. In order that the potential of this technique in this field could be evaluated, large-sized coal samples were examined. The PA difference spectra obtained from the spectra taken at different modulation frequencies (i.e., different depths), on a sample aged in air, demonstrate the appearance of negative features in the CH infrared absorption which are indicative of a coal alteration. Therefore, different coal layers can be distinguished by FT-IR/PAS. The application of the same technique to the study of a coal sample heated in air at 200°C allows the detection of different oxidation mechanisms operating inside and outside the coal. Although quantitative results are difficult to obtain, the technique can be successfully proposed for a qualitative description of coal weathering.

scholarly journals An Essential Role of Polymeric Adhesives in the Reinforcement of Acidified Paper Relics

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 207
Author(s):  
Jiaojiao Liu ◽  
Huiping Xing ◽  
Yajun Zhou ◽  
Xiaolian Chao ◽  
Yuhu Li ◽  
...  
Keyword(s):  
Essential Role ◽  
Polyvinyl Butyral ◽  
Scientific Basis ◽  
Water Soluble ◽  
Wheat Starch ◽  
Protective Effects ◽  
Ft Ir ◽  
Starch Paste

Paper acidification causes paper relics to undergo embrittlement and decay, to form dregs, and even to break upon a single touch; therefore, reinforcement and deacidification treatments are essential steps for paper conservation and to retard the deterioration and prolong the life of objects. Polymeric adhesives play an essential role in reinforcement and deacidification treatments, although it is not well studied. In this work, the effect of polymeric adhesives on the conservation process and their protective effects on acidified paper relics were studied. Firstly, three polymeric adhesives, including wheat starch paste, polyvinyl butyral (PVB), and polyvinyl alcohol (PVA), were selected as research objects. Subsequently, their effects on four popular conservation methods were further discussed, including traditional mounting, hot-melt with silk net, alcohol-soluble cotton mesh, and water-soluble cotton mesh. Additionally, as an example, the reversibility and long-term durability of water-soluble adhesive PVA-217 were assessed. Using a computer measured and controlled folding endurance tester, pendulum tensile strength tester, tear tester, burst tester, FT-IR, video optical contact angle tester, and other instruments, the conservation application of water-soluble adhesives in paper relics was evaluated. This study provides a scientific basis and experimental data for the application of polymeric adhesives in the conservation of paper relics.

scholarly journals The Role of Carboxyl and Hydroxyl Groups of Humic Acid in Removing AuCl4- from Aqueous Solution

2017 ◽  
Vol 17 (1) ◽  
pp. 95 ◽  
Author(s):  
Sri Sudiono ◽  
Mustika Yuniarti ◽  
Dwi Siswanta ◽  
Eko Sri Kunarti ◽  
Triyono Triyono ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Peat Soil ◽  
Sharp Decrease ◽  
Hydroxyl Groups ◽  
Mixed Solution ◽  
Oh Groups ◽  
Characterization Result ◽  
Ft Ir

Humic acid (HA) extracted from peat soil according to the recommended procedure of the International Humic Substances Society (IHSS) has been tested to remove AuCl4- from aqueous solution. The removal was optimum at pH 2.0 and it was mainly dictated by attachment through hydrogen bonding to unionized carboxyl (–COOH) groups and reduction by the action of the hydroxyl (–OH) groups to gold (Au) metal. The removal of AuCl4- improved after HA was purified through repeated immersion and shaking in a mixed solution containing 0.1 M HCl and 0.3 M HF. When the purification led to the sharp decrease in ash content from 39.34 to 0.85% (w/w) and significant increase in both the –COOH and –OH contents from 3240 to 3487 mmol/kg and from 4260 to 4620 mmol/kg, respectively; the removal of AuCl4- improved from 0.105 to 0.133 mmol/g. This improvement of AuCl4- removal by the purified HA was accompanied by higher ability in reduction to Au metal. The attached AuCl4- on –COOH groups of both crude and purified HAs was qualitatively observed by the characterization result of FT-IR spectroscopy, while the presence of Au metal on the surface of those HAs was verified by the characterization result of XRD.

Sign in / Sign up

Export Citation Format

Share Document