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Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1224
Author(s):  
Vut Tongnan ◽  
Youssef Ait-lahcen ◽  
Chuthamas Wongsartsai ◽  
Chalempol Khajonvittayakul ◽  
Nuchanart Siri-Nguan ◽  
...  

A slight amount of Cr2O3 segregation in 40 wt% NiO/Ce0.5Cr0.5O2 was presented at the surface. The best catalytic performance towards the reaction was achieved at 74% of CO2 conversion and 100% CH4 selectivity at 310 °C, the reactant (H2/CO2) feed molar ratio was 4, and the WHSV was 56,500 mlN·h−1·g−1cat. The mechanistic pathway was proposed through carbonates and formates as a mediator during CO2 and H2 interaction. Activation energy was estimated at 4.85 kJ/mol, when the orders of the reaction were ranging from 0.33 to 1.07 for nth-order, and 0.40 to 0.53 for mth-order.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mostafa Nikkhah Dafchahi ◽  
Hossein Resalati ◽  
Seyed Majid Zabihzadeh ◽  
Noureddin Nazarnezhad ◽  
Ghasem Asadpour ◽  
...  

Abstract Precipitated calcium carbonate (PCC) filler is used in many industrial products like constructions, plastics, pharmaceutics, etc. In this study producing cationic precipitated calcium carbonate filler for paper industry was investigated. Hence, a cationic polyacrylamide and cationic corn starch have been incorporated into the PCC particles to produce a modified filler with cationic structure and improved hydrogen bonding ability with cellulose fibers. According to the FESEM and XRD results, cubic-like fillers with prominently calcite polymorph and a slight amount of aragonite were successfully produced from the industrial burnt lime using carbonation process. The presence of organic substances in the structure of the modified samples was confirmed by FT-IR analysis. Besides, based on the FESEM results, filler morphology and particle size could be affected by the polymer content. In conclusion, introducing cationic groups to mineral fillers could be considered as a possible strategy to overcome some detrimental effects of using mineral fillers in paper products.


2021 ◽  
pp. 1-10
Author(s):  
E.C. Michelin ◽  
C.M. Bedoya-Serna ◽  
L.C.S. Carrion ◽  
S.H.S. Godoy ◽  
J.C. Baldin ◽  
...  

The objective of this work was to evaluate the aflatoxins residues on tissues of Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins, also evaluating the effects on fish performance. Aflatoxins were incorporated into the extruded fish feed and the concentrations were confirmed by high performance liquid chromatography (HPLC). The experimental design comprised the following treatments: Control – feed without toxin; Treatment A: feed + 10 μg aflatoxin B1 (AFB1)/kg; Treatment B: feed + 20 μg AFB1/kg and Treatment C: feed + 50 μg AFB1/kg. Pacu juvenile were allocated in tanks with density of one fish per litter. The experiment lasted 180 days with monthly sampling, and approximately ten fish per treatment were used to compose a sample. Biometric surveys were performed every 30 days, including standard weight and length. Aflatoxins were detected and quantified in fish muscle and liver by HPLC, using immunoafinity columns. Results showed AFB1 deposition in the liver throughout the experiment in all treatments, but only treatment C differed significantly (P<0.05) from the others after 150 days, while in muscle there was low residual deposition. Long-term exposed fish had negative influence in weight and length. The higher mortality was observed in treatment C. Although there were AFB1 residues at low levels in liver and only a slight amount in fish muscle, it should be noted that accumulation is possible in the Pacu species. The diets contaminated with AFB1 negatively interfered in weight and length of fish when compared to control. Therefore, it can be concluded that long-term exposure of Pacu to dietary AFB1 can cause losses to producers.


2021 ◽  
Author(s):  
Douglas A Irwin ◽  
Maksym G Chepeliev

Abstract This paper provides a quantitative general equilibrium evaluation of the repeal of Britain's Corn Laws in 1846. Using a detailed input-output matrix of the British economy in 1841, we find the abolition of Britain's tariff on imported grain left overall welfare roughly unchanged as the static efficiency gains are offset by terms-of-trade losses. Labourers and capital owners gained a slight amount at the expense of landowners. Combining these changes in factor payments with the different consumption patterns across income groups, we find that the top 10% of income earners lost while the bottom 90% of income earners gained.


2020 ◽  
Vol 40 (6) ◽  
pp. 756-760
Author(s):  
Thomas A Hegna ◽  
Andrew D Czaja ◽  
D Christopher Rogers

Abstract Clam shrimps constitute a paraphyletic group of bivalved branchiopod crustaceans that includes orders Laevicaudata, Spinicaudata, and Cyclestherida. The unique mineral content of the carapace, formed by molt retention in Spinicaudata and Cyclestherida, has been variously ascribed to calcium carbonate or calcium phosphate. We analyzed the composition of modern carapaces from one laevicaudatan species, thirteen spinicaudatan species (including cyzicids, leptestheriids, and limnadiids), one cyclestherid species, and two species of the notostracan TriopsSchrank, 1803 (as an outgroup comparison within Branchiopoda) via Raman spectroscopy. The results were surprisingly variable. The outgroup Triops species varied in either having no mineral content to having a slight amount of calcium phosphate. The laevicaudatans likewise had a minor calcium phosphate peak; the leptestheriid spinicaudatan had strong calcium phosphate and calcium carbonate peaks; the limnadiid spinicaudatans were variable, varying from no mineral content to strong dual calcium carbonate and calcium phosphate peaks; the cyzicid spinicaudatans tended to have strong calcium phosphate peaks with some amount of calcium carbonate; and the cyclestherid had no mineral content. The results support the conclusion that spinicaudatans primitively have a dual mineralization system in their carapace that utilizes both calcium phosphate and calcium carbonate, with the calcium phosphate ability being basal. This suggestion of a dual mineralization system is novel in branchiopods and warrants study from material scientists. Better understanding of the distribution of phosphate versus carbonate among modern spinicaudatans will help us understand the evolution of biomineralization in the group. This, in turn, will shed light on the fossilization potential of different fossil clam-shrimp lineages.


2020 ◽  
Vol 6 (2) ◽  
pp. 112-114
Author(s):  
Ashish Agarwal ◽  
Shiva Shankar Gummaluri

Migration or drifting of teeth is always multifactorial. This is one of the major concerns in the field of dentistry. On long standing periodontal disease this pathological migratory phenomenon occurs. Treating this pathological tooth migration requires some of the modalities like periodontal therapy/ orthodontic therapy/ restorative therapy. But in some cases periodontal therapy alone plays an important role in spontaneous correction of PTM. Present case report also demonstrate the spontaneous correction of mandibular anterior tooth proclination and slight amount of open bite with non- surgical periodontal therapy (periodontal therapy) alone


LingVaria ◽  
2020 ◽  
pp. 135-144
Author(s):  
Aleksandra Janowska

PROBLEMS IN THE DESCRIPTION OF OLD POLISH VERBAL DERIVATION The article discusses the problems associated with the description of verbal derivation in the earliest period of the Polish language. The type of linguistic material that was preserved, the slight amount of attestations, the lack of clarity of the context, are all responsible for the appearance of difficulties associated with the word-formative description of verbs already at the level of the separation of linguistic facts, the establishment of the formant that we are dealing with. Even greater problems are associated with the establishment of the semantic value of derivatives, and with the indication of motivation relations. The author considers the extent to which the methodology that was developed upon contemporary material may be used in research of this kind. She also points out the scholarly ‘neglected’ areas of verbal word-formation of this period.


Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2030 ◽  
Author(s):  
Qing Liu ◽  
Yuka Yoshida ◽  
Naoto Nakazawa ◽  
Satoshi Inagaki ◽  
Yoshihiro Kubota

During prior investigations of the synthesis of the novel zeolite YNU-5 (YFI), it was found that a very slight amount of an impurity phase contaminated the desired zeolitic phase. This impurity was very often ZSM-5 (MFI). The phase composition was determined to be sensitive to the water in the synthesis mixture, and it was possible to obtain a pure phase and also to intentionally generate a specific impurity phase. In the present work, trials based on the dimethyl ether-to-olefin (DTO) reaction using a fixed-bed downflow reactor were performed to assess the effect of the purity of YNU-5 on its catalytic performance. Dealuminated pure YNU-5 exhibited rapid deactivation due to coking at time on stream (TOS) values exceeding 5 min. Surprisingly, this deactivation was greatly suppressed when the material contained a trace amount of ZSM-5 consisting of nano-sized particles. The formation of ZSM-5 nanoparticles evidently improved the performance of the catalytic system during the DTO reaction. The product distributions obtained from this reaction using highly dealuminated and very pure YNU-5 resembled those generated by 12-ring rather than 8-ring zeolite catalysts. The high selectivity for desirable C3 and C4 olefins during the DTO reaction over YNU-5 is beneficial.


Polymer ◽  
2019 ◽  
Vol 185 ◽  
pp. 121989
Author(s):  
Wenhao Li ◽  
Jian Hu ◽  
Li Cheng ◽  
Long Chen ◽  
Lijuan Zhou ◽  
...  

Cellulose ◽  
2019 ◽  
Vol 26 (17) ◽  
pp. 9323-9333 ◽  
Author(s):  
Jing Zhou ◽  
XinYue Hu ◽  
YiYuan Zhu ◽  
HongFen Lyu ◽  
Lei Zhang ◽  
...  

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