Reaction kinetics and pathway of crotonic acid conversion in sub- and supercritical water for renewable fuels production

2021 ◽  
Author(s):  
Diane Valenzuela Gubatanga ◽  
Osamu Sawai ◽  
Teppei Nunoura
Keyword(s):  
Reaction Kinetics ◽  
Supercritical Water ◽  
Reaction Network ◽  
Current Treatment ◽  
Crotonic Acid ◽  
Renewable Fuels ◽  
Treatment Methods ◽  
Green Approach

Conversion of waste lipid biomass into renewable fuels using sub- and supercritical water provides an alternative green approach in contrast with the current treatment methods. However, the reaction network of...

Chronic Spontaneous Urticaria (CSU)

2016 ◽  
Vol 20 (4) ◽  
pp. 308-312 ◽  
Author(s):  
Loretta Y. Cheung ◽  
Charles W. Lynde
Keyword(s):  
Skin Disorder ◽  
Response Rate ◽  
Current Treatment ◽  
Chronic Spontaneous Urticaria ◽  
Treatment Methods ◽  
Practice Survey ◽  
New Therapies ◽  
Oral Corticosteroids ◽  
Current Therapies ◽  
Physical Stimuli

Background: Chronic spontaneous urticaria (CSU) is a skin disorder that is said to be “frustrating” and “difficult to treat.” It is characterized by recurrent hives for more than 6 weeks, and is further divided into spontaneous or inducible by physical stimuli.1 To better understand dermatologists’ perspective of this disorder, a survey was conducted with Canadian dermatologists. Methods: A detailed online practice survey was sent to all currently practicing Canadian dermatologists. Results: In all, 80 responses were received (response rate of 20%). Most respondents in Canada had treated patients with CSU (98.4%), with many of the patients having the disease last over 6 months (86.6%). A majority of the patients were female, with 84.1% of the respondents having over 50% of their patients as female. Most patients were over the age of 30 (74.2%). Of dermatologists, 85.7% felt that investigations were unhelpful in diagnosing CSU in a patient. Of respondents, 37.1% were not satisfied with current treatment methods of CSU, and 43.6% somewhat satisfied. Popular therapies included H1 and H2 antihistamines, oral corticosteroids, and montelukast. There were 16.1% of dermatologists who had over 50% of their patients refractory to treatment. Conclusions: There was a clear demographic preponderance for CSU patients with a majority as female over age 30. Investigations ordered for CSU patients do not seem to be helpful among dermatologists. Satisfaction with current therapies and investigations was quite low among Canadian dermatologists, suggesting new therapies are indicated.

Reaction Kinetics of the Lignin Conversion in Supercritical Water

2012 ◽  
Vol 51 (37) ◽  
pp. 11975-11988 ◽  
Author(s):  
Tau Len-Kelly Yong ◽  
Yukihiko Matsumura
Keyword(s):  
Reaction Kinetics ◽  
Supercritical Water ◽  
Kinetics Of

Observations on the current treatment of low-grade astrocytic tumors of the cerebral hemispheres

1987 ◽  
Vol 67 (2) ◽  
pp. 177-181 ◽  
Author(s):  
Joseph M. Piepmeier
Keyword(s):  
Contrast Material ◽  
Tumor Location ◽  
Current Treatment ◽  
Cerebral Hemispheres ◽  
Ct Scans ◽  
Low Grade ◽  
Astrocytic Tumors ◽  
Treatment Methods ◽  
Content Type ◽  
Definition Of

✓ The records of 60 patients with low-grade astrocytic tumors of the cerebral hemispheres treated between 1975 and 1985 were examined to evaluate the results of current treatment methods. This analysis revealed that the patient's age and tumor enhancement on computerized tomography (CT) with intravenous administration of contrast material were the only factors that influenced survival time. Compared to prior studies, the patients in this report more frequently had normal preoperative neurological examinations and total resection of their lesions. These differences may have resulted from the use of CT scans over the past decade. Earlier diagnosis and improvement definition of the tumor location and extent are two reasons why the use of CT scans may have affected outcome statistics. A re-examination of treatment methods and the timing of those treatments is needed to define the optimal management of these lesions.

Kinetics for an Optimized Biosynthesis of Silver Nanoparticles Using Alfalfa Extracts

2015 ◽  
Vol 13 (3) ◽  
pp. 359-367
Author(s):  
José J. Ibarra-Sánchez ◽  
Rosalba Fuentes-Ramírez ◽  
José Antonio Reyes-Aguilera ◽  
Susana Figueroa-Gerstenmaier ◽  
Erasmo Orrantia-Borunda ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Silver Nanoparticles ◽  
Reaction Kinetics ◽  
Scale Up ◽  
Degree Of Crystallinity ◽  
Plant Metabolites ◽  
Initial Concentration ◽  
Extraction Solvent ◽  
Green Approach ◽  
Best Value

Abstract In recent years, great efforts have been directed to provide eco-friendly methods for nanoparticles (NPs) synthesis. In this endeavor, it is desired that polydispersity be as narrow as possible and that the chemical and physical properties can be controlled. In this work, silver nanoparticles (SNPs) were obtained by means of (a) a green approach (biosynthesis) using alfalfa extracts; and (b) a thermal decomposition method in organic media. As per biosynthesis, pH, initial concentration of precursor (Ag+) and extraction solvent of plant metabolites were varied in order to identify the conditions where SNP polydispersity presented a best value. When these conditions were determined, the reaction kinetics was evaluated. The rate constant and order of reaction were 7.33×10−6 L3.6/mol3.6 s, and 4.6, respectively. Also, in the biosynthesis, it was found that the size and the degree of polydispersity depend on initial concentration of precursor and the type of extractant. Thermal decomposition was performed using silver oleate as precursor in order to compare characteristics of the NPs obtained by both biosynthesis and the chemical method. According to our results, SNPs obtained through thermal decomposition showed a lower polydispersity and higher degree of crystallinity than those obtained using biosynthesis. However, the green method eliminates the use of toxic compounds, which is extremely important if these particles are intended for biomedical purposes. In addition, this is a less expensive method as compared to other chemical methods. To our knowledge, this is one of the few reports analyzing the reaction kinetics, which is extremely important if scale-up is intended.

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