scholarly journals DIFERENCIAÇÃO CATIÔNICA DE BENTONITAS POR INFRAVERMELHO: UM ESTUDO DOS EFEITOS DA HIDRATAÇÃO DOS CÁTIONS TROCÁVEIS

Química Nova ◽  
2021 ◽  
Author(s):  
Andréia Rodrigues ◽  
Rômulo Angélica ◽  
Simone Paz
Keyword(s):  
Quality Control ◽  
Near Infrared ◽  
Exchangeable Cations ◽  
The Other ◽  
Activation Process ◽  
Effective Technique ◽  
Common Procedure ◽  
Mir Spectroscopy ◽  
Sodium Activation ◽  
Hydrated Sample

CATIONIC DIFFERENTIATION OF BENTONITES BY INFRARED: A STUDY OF THE HYDRATION EFFECTS OF EXCHANGEABLE CATIONS. In the bentonite industry, the most common procedure for quality control of the ore and the sodium activation process is the swelling method. However, this tool is restricted only to the differentiation of the sodium and non-sodium types, not considering the other cationic varieties. The objective of this study was to establish parameters for cationic differentiation of bentonites based on Near Infrared (NIR) and Medium (MIR) spectroscopy, which proved to be an effective technique in the cationic differentiation of bentonites using the characteristic bands “7072 cm-1” and “3620 and 3430 cm-1” under the condition of the dry-hydrated sample and not under the anhydrous condition. NIRS can be considered a measure of great scientific and technological contribution, as it allows the cationic differentiation of bentonites in a practical way and with low analytical cost.

Dry chip feedrate control using online chip moisture

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 295-305
Author(s):  
Wesley Gilbert ◽  
Ivan Trush ◽  
Bruce Allison ◽  
Randy Reimer ◽  
Howard Mason
Keyword(s):  
Production Rate ◽  
Control Strategy ◽  
Rate Control ◽  
Near Infrared ◽  
Dry Mass ◽  
The Other ◽  
Process Variability ◽  
Moisture Sensor ◽  
Feedback Control Strategy ◽  
And Control

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.

scholarly journals An Indigenous Method of Securing Ventriculoperitoneal Shunt Tube in Peritoneal Cavity

2021 ◽  
Author(s):  
Samir Kumar Kalra ◽  
Krishna Shah ◽  
Sneyhil Tyagi ◽  
Suviraj John ◽  
Rajesh Acharya
Keyword(s):  
Ventriculoperitoneal Shunt ◽  
Operation Time ◽  
Complication Rates ◽  
Effective Technique ◽  
Common Procedure ◽  
Shunt System ◽  
Shunt Tube ◽  
Csf Diversion ◽  
Median Operation Time

Abstract Introduction Ventriculoperitoneal shunt (VPS) is the most common procedure used for cerebrospinal fluid (CSF) diversion in hydrocephalus. Over the years, many technical, procedural, and instrument-related advancements have taken place which have reduced the associated complication rates. Shunt block is a very common complication irrespective of the shunt system used. The abdominal end of the shunt tube gets blocked usually due to plugging of omentum onto the shunt catheter. We describe a technique of catheter fixation and placement under vision coupled with omentopexy done laparoscopically to prevent this complication. Materials and Methods This technique was used in 23 patients (11 female, 12 male; range 16–73 years) afflicted with hydrocephalus from June 2016 and December 2019 after obtaining an informed consent, and the outcomes were noted in terms of shunt patency, complications, if any, and the need for revision. Results The median operation time was 90 minutes (range 35–160 minutes). All shunt catheters were still functional after a mean follow-up of 16.5 months (range 1–34 months) and none required revision. Conclusion Laparoscopic placement of shunt tube along with omental folding is a safe and effective technique for salvaging the abdominal end of VPS and may be helpful in reducing shunt blockage.

scholarly journals Application of Near-Infrared Spectroscopy Analysis Technology to Total Nucleosides Quality Control in the Fermented Cordyceps Powder Production Process

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tiannv Shi ◽  
Yongmei Guan ◽  
Lihua Chen ◽  
Shiyu Huang ◽  
Weifeng Zhu ◽  
...  
Keyword(s):  
Quality Control ◽  
Infrared Spectroscopy ◽  
Production Process ◽  
Process Monitoring ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Powder Preparation ◽  
Spectroscopy Analysis ◽  
Online Process Monitoring ◽  
Online Process

Product quality control is a prerequisite for ensuring safety, effectiveness, and stability. However, because of the different strain species and fermentation processes, there was a significant difference in quality. As a result, they should be clearly distinguished in clinical use. Among them, the fermentation process is critical to achieving consistent product quality. This study aims to introduce near-infrared spectroscopy analysis technology into the production process of fermented Cordyceps powder, including strain culture, strain passage, strain fermentation, strain filtration, strain drying, strain pulverizing, and strain mixing. First, high performance liquid chromatography (HPLC) was used to measure the total nucleosides content in the production process of 30 batches of fermented Cordyceps powder, including uracil, uridine, adenine, guanosine, adenosine, and the process stability and interbatch consistency were analyzed with traditional Chinese medicine (TCM) fingerprinting, followed by the near-infrared spectroscopy (NIRS) combined with partial least squares regression (PLSR) to establish a quantitative analysis model of total nucleosides for online process monitoring of fermented Cordyceps powder preparation products. The model parameters indicate that the established model with good robustness and high measurement precision. It further clarifies that the model can be used for online process monitoring of fermented Cordyceps powder preparation products.

Near-Infrared Combination and Overtone Bands of CH in CHX3, CHX2—CHX2, and CHX2—CX2—CHX2

2005 ◽  
Vol 59 (11) ◽  
pp. 1393-1398 ◽  
Author(s):  
Reikichi Iwamoto ◽  
Akishi Nara ◽  
Toshihiko Matsuda
Keyword(s):  
Excited State ◽  
Near Infrared ◽  
Present Report ◽  
Spectral Characteristics ◽  
The Other ◽  
Coupled Modes ◽  
Third Order ◽  
The Third ◽  
Combination Bands ◽  
Deformation Modes

In the present report we studied spectral characteristics of the near-infrared combination and overtone bands of CH vibrations of a CH sequence. The near-infrared bands of the CH in CHX3 (X, halogen), which were interpreted in terms of the CH stretching and CH deformation fundamentals without any ambiguity, typically showed how the frequency and intensity of a combination or an overtone depend on the vibrational excited state. In the CH–C–CH of CHX2CX2CHX2, the vibrations of one CH are isolated from those of the other CH, and the combination and overtone bands were similarly interpreted as those of the CH, although each of the combination bands was split into two because of non-degeneracy of the CH deformation. In the CH–CH of CHX2CHX2, the CH deformations only have coupled modes. The first combination showed four narrowly separate bands, which were reasonably interpreted on the basis of the CH stretching and the coupled CH deformation modes. We demonstrated that the first combination of coupled modes as well as the combination of up to, at least, the third order of isolated modes have the nature of the characteristic bands.

scholarly journals A fast and low-cost approach to quality control of alcohol-based hand sanitizer using portable near infrared spectrometer and chemometrics

2021 ◽  
pp. 096703352098731
Author(s):  
Adenilton C da Silva ◽  
Lívia PD Ribeiro ◽  
Ruth MB Vidal ◽  
Wladiana O Matos ◽  
Gisele S Lopes
Keyword(s):  
Quality Control ◽  
Discriminant Analysis ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Partial Least Square ◽  
Least Square ◽  
Chemical Components ◽  
Linear Discriminant ◽  
Hand Sanitizer

The use of alcohol-based hand sanitizers is recommended as one of several strategies to minimize contamination and spread of the COVID-19 disease. Current reports suggest that the virucidal potential of ethanol occurs at concentrations close to 70%. Traditional methods of verifying the ethanol concentration in such products invite potential errors due to the viscosity of chemical components or may be prohibitively expensive to undertake in large demand. Near infrared (NIR) spectroscopy and chemometrics have already been used for the determination of ethanol in other matrices and present an alternative fast and reliable approach to quality control of alcohol-based hand sanitizers. In this study, a portable NIR spectrometer combined with classification chemometric tools, i.e., partial least square discriminant analysis (PLS–DA) and linear discriminant analysis with successive algorithm projection (SPA–LDA) were used to construct models to identify conforming and non-conforming commercial and laboratory synthesized hand sanitizer samples. Principal component analysis (PCA) was applied in an exploratory data study. Three principal components accounted for 99% of data variance and demonstrate clustering of conforming and non-conforming samples. The PLS–DA and SPA–LDA classification models presented 77 and 100% of accuracy in cross/internal validation respectively and 100% of accuracy in the classification of test samples. A total of 43% commercial samples evaluated using the PLS–DA and SPA–LDA presented ethanol content non-conforming for hand sanitizer gel. These results indicate that use of NIR spectroscopy and chemometrics is a promising strategy, yielding a method that is fast, portable, and reliable for discrimination of alcohol-based hand sanitizers with respect to conforming and non-conforming ethanol concentrations.

scholarly journals Unidentified emission features in the R Coronae Borealis star V854 Centauri

2018 ◽  
Vol 610 ◽  
pp. L6 ◽  
Author(s):  
L. C. Oostrum ◽  
B. B. Ochsendorf ◽  
L. Kaper ◽  
A. G. G. M. Tielens
Keyword(s):  
Near Infrared ◽  
Physical Nature ◽  
The Other ◽  
Large Telescope ◽  
Circumstellar Material ◽  
Spatially Resolved ◽  
Broad Emission ◽  
Very Large Telescope ◽  
New Feature ◽  
Molecular Nature

During its 2012 decline, the R Coronae Borealis star (RCB) V854 Cen was spectroscopically monitored with X-shooter on the ESO Very Large Telescope. The obscured optical and near-infrared spectrum exhibits many narrow and several broad emission features, as previously observed. The envelope is spatially resolved along the slit and allows for a detailed study of the circumstellar material. In this Letter, we report on the properties of a number of unidentified visual emission features (UFs), including the detection of a new feature at 8692 Å. These UFs have been observed in the Red Rectangle (RR), but their chemical and physical nature is still a mystery. The previously known UFs behave similarly in the RR and in V854 Cen, but are not detected in six other observed RCBs. Some hydrogen might be required for the formation of their carrier(s). The λ8692 UF is present in all RCBs. Its carrier is likely of a carbonaceous molecular nature, presumably different from that of the other UFs.

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