Precipitation Kinetics of the Titanium Isopropoxide Hydrolysis Reaction

1986 ◽  
Vol 73 ◽  
Author(s):  
R. W. Hartel ◽  
K. A. Berglund

ABSTRACTThe precipitation product of the titanium isopropoxide (TiPT) hydrolysis reaction was followed using photon correlation spectroscopy. This technique followed the mean size of the precipitate as the reaction progressed, as well as giving an indication of the number of particles being produced. From this analysis, the induction time for the onset of nucleation, nucleation rate (or the rate of particle production) and mean growth rate were correlated with reactant concentrations. In the concentration ranges studied, it was found that the induction time was a very strong inverse function of the reactant concentrations. Both nucleation rate and average growth rate were found to increase very rapidly as reactant concentration increased, with the TiPT concentration being more important. This reaction was also followed using absorbance spectrophotometry in the 500 to 320 nm range. After mixing of the reactants, an absorbance peak was seen between 330 and 335 nm, depending on the conditions. This peak increased slowly during the induction period and then increased rapidly after the onset of nucleation due to the increasing turbidity.

Author(s):  
Dongxu Zhang ◽  
Qiyu Huang ◽  
Wei Wang ◽  
Rongbin Li ◽  
Huiyuan Li ◽  
...  

Asphaltene was fractionated into four subfractions with different polarities, and used to conduct the hydrate formation and dissociation experiments. It was observed that the more polar fraction could result in a higher tendency of self-aggregation and fewer asphaltenes adsorbing at the water-oil interface mainly due to the larger C/H ratio, higher aromaticity, and shorter length of the alkyl side chain. The nucleation rate decreased with the presence of asphaltenes, and the induction time increased with a reduction in asphaltene polarity in water-in-oil emulsions. The results showed that the formed amount of hydrates were reduced by the addition of asphaltenes. For the asphaltene containing emulsions, less hydrate was formed with the presence of a more polar asphaltene fraction. The presence of asphaltenes was also found to affect the growth rate of hydrate, which varies with the polarity. Meanwhile, all four asphaltene fractions were found to promote the dissociation of hydrate.


2021 ◽  
Vol 2076 (1) ◽  
pp. 012086
Author(s):  
Shuai Wu ◽  
Mingzhong Li ◽  
Chongrui Zhang ◽  
Chengwei Liu ◽  
Shuai Zhao ◽  
...  

Abstract In order to explore the kinetic mechanism of hydrate formation in a system containing micron-sized SiO2 particles, this paper uses a high-pressure reactor device with stirring function to record changes in pressure, temperature and torque during the growth of hydrates through a data acquisition system, based on the conservation of mass in the system The principle and gas equation of state calculate the kinetic parameters of hydrate formation such as gas consumption in the reactor, hydrate formation rate and induction time, and analyze the influence of particle size and particle concentration on the kinetic characteristics of hydrate formation based on the experimental results. The experimental results show that the particle content has no obvious effect on the average growth rate of hydrate in the range of 1%-7%, but increasing the particle content can effectively reduce the hydration induction time; when the particle size is in the range of 2.5-85 μm, the larger the particle size, the shorter the hydrate induction time and the greater the hydrate growth rate.


Author(s):  
Farida . ◽  
Eka Indah Raharjo ◽  
Arnis Maylinda Sari

ABSTRAKPenelitian bertujuan untuk mengetahui penggunaan fermentasi bungkil kelapa sawit dalam pakan buatan.Penelitian menggunakan Rancangan Acak Lengkap (RAL) yang terdiri dari 4 perlakuan 3 ulangan.Susunan perlakuan adalah Perlakuan A : bungkil kelapa sawit 12%, Perlakuan B : fermentasi bungkil kelapa sawit 15%, Perlakuan C : fermentasi bungkil kelapa sawit 18%, Perlakuan D : fermentasi bungkil kelapa sawit 21%. Penelitian ini dilakukan selama 60 hari untuk mengetahui laju pertumbuhan spesifikberat, laju pertumbuhan harianpanjang, konversi pakan, kelangsungan hidup dan kualitas air sebagai penunjang.Hasil penelitian menunjukkan pemberian pakan buatan dengan fermentasi bungkil kelapa sawit menghasilkan respon yang baik terhadap pertumbuhan ikan gurami. Pemberian pakan buatan dengan fermentasi bungkil kelapa sawit 18% (perlakuan C), memberikan hasil terbaik dengan laju pertumbuhan dengan rata – rata laju pertumbuhan spesifik berat 1.502%, laju pertumbuhan harian panjang 4.06%, nilai konversi pakan rata – rata 3.48 dan kelangsungan hidup rata – rata 90%.Kata Kunci : Fermentasi Bungkil Kelapa Sawit, Ikan Gurami, Laju PertumbuhanThe study aims to determine the use of fermentation residue oil palm in artificial feed .Research using a completely randomized design ( CRD ), which consists of 4 treatment three replications.The composition of the treatment is the treatment  A : 12 % of palm oil cake , Treatment B : fermented palm oil cake 15 % , Treatment C : fermented palm oil cake 18 % , Treatment D : fermentation residue palm oil 21 %.This research was conducted for 60 days to determine the specific growth rate of heavy , long daily growth rate , feed conversion , survival and quality of water as a supporter.The results showed the artificial feeding with fermented palm cake to produce a good response to the growth of carp.Feeding artificially by fermentation cake palm oil 18 % ( treatment C ) , gives the best results with a growth rate with the average - average growth rate of the specific weight of 1.502 % daily growth rate long- 4:06 % , the value of feed conversion average - average 3:48 and median survival - average of 90 % .Keywords : Fermentation Palm Kernel Oil, Fish carp, Growth Rate


2014 ◽  
Vol 9 (3) ◽  
pp. 201-213
Author(s):  
Renata Marks-Bielska ◽  
Wiesława Lizińska ◽  
Izabela Serocka

Evaluation of the importance of the USA as the trade partner of Poland is the main objective of the paper, based on the changes in the value of trade during the years 2000-2012 and changes in the structure of trade during the years 2008-2012. The data from the Statistical Yearbooks of Foreign Trade published by the Central Statistical Office was used. The potential for foreign trade growth was illustrated using the simplified analysis based on the gravity model of foreign trade concept. Gradually increasing value of Polish trade with the USA (the average growth rate 9.8%, EU-15 countries 13.1%). Polish exports are characterised by a higher than imports growth rate (USA - exports growth by 12.5%, imports 9.2%, EU-15 - exports 15.1%, imports 11.6%). Trade is strongly dominated by position of one group of products (over 30% share in both exports and imports). The potential of trade is poorly exploited currently. Trade was focused mainly on the countries situated in the close neighbourhood (mainly the EU countries with the domination of Germany).


1999 ◽  
Vol 55 (2) ◽  
pp. 577-580 ◽  
Author(s):  
Abel Moreno ◽  
Manuel Soriano-García

In attempts to obtain protein crystals of a sufficient size for structural studies, lack of knowledge of the physicochemical properties of protein solutions and of their crystal-growth behaviour lead to a bottleneck for drug design as well as for X-ray crystallography. Most formal investigations on crystal-growth phenomena have been focused on equilibrium studies, where the protein is soluble, and on the kinetics of crystal growth, which is related to both nucleation and crystal-growth phenomena. The aim of this work is to measure the crystal-growth rate along a capillary tube used as a growing cell. These experiments were carried out using the gel-acupuncture technique [García-Ruiz et al. (1993). Mater. Res. Bull. 28, 541–546; García-Ruiz & Moreno (1994). Acta Cryst. D50, 484–490; García-Ruiz & Moreno (1997). J. Cryst. Growth, 178, 393–401]. Crystal-growth investigations took place using lysozyme and thaumatin I as standard proteins. The maximum average growth rate obtained in the lower part of the capillary tube was about 35 Å s−1 and the minimum average growing rate in the upper part of the capillary tube was about 8 Å s−1. The crystal-growth rate as a function of the supersaturation was experimentally estimated at a constant height along the capillary tube.


2021 ◽  
Vol 21 (02) ◽  
pp. 17545-17559
Author(s):  
PA Otieno ◽  
◽  
DO Owiti ◽  
PO Onyango ◽  
◽  
...  

Aquaculture offers the opportunity for safeguarding local and global food security in the face of declining capture fisheries. However, the form of aquaculture that is commonly practiced in Kenya is characterized by the use of agrochemicals such as fertilizers that negatively impact biodiversity especially when effluents from fish ponds drain into water bodies. This study aimed to determine differences in the growth rate of Clarias gariepinus, an important aquaculture fish in Kenya, to assess plankton diversity, and to identify phytoplankton species associated with pollution under organic and inorganic fertilization regimens using chicken manure, Diammonium phosphate, and urea, respectively. Average growth rate calculated per day was higher in the organically-fertilized ponds at 0.06 cm/day, followed by inorganically-fertilized ponds at 0.05cm/day and then, the control at 0.04 cm/day. Average weight gain was higher in organically-fertilized ponds at 0.08 g/day followed by ponds fertilized with inorganic fertilizer at 0.07 g/day and the control, at 0.06g/day. There were significant differences in growth rate across fertilization regimens (length: F2, 264= 24.06, p = 0.0399; weight: F2, 264 = 20.89, p = 0. 0457). Specifically, although differences in growth rate of fish in organically and inorganically fertilized ponds were not significant, fish in fertilized ponds were on average, longer and weighed more than those in the control pond. Jaccard’s similarity index for phytoplankton was highest (0.38) between organically-fertilized ponds and control but lowest (0.25) between inorganically-fertilized ponds and control. Use of chicken manure produced the highest diversity of zooplankton (Shannon-Weiner’s H in organically-fertilized pond = 1.886; inorganic = 1.044, and control = 0.935). The use of DAP and urea produced the highest proportion of phytoplankton species associated with pollution. These results do not support the commonly reported notion that ponds fertilized using inorganic fertilizers are more productive. Findings suggest that the use of inorganic fertilizers may threaten biodiversity in aquatic ecosystems through the production of toxic algae.


2021 ◽  
Vol 9 (08) ◽  
pp. 647-650
Author(s):  
Maryama Gul ◽  
◽  
P.K. Sanse ◽  

The objective of this study was to assess the performance of JK SFC. The establishment of State financial Corporations was, one of the steps taken, at the official level to promote the growth of small and mediumscale industries. The Jammu and Kashmir State Financial Corporation is a statutory Corporation established under SFCs Act 1951(Central Act 63 of 1951) which is facing heavy losses due to no source of funds and no recovery of loans. In the present study performance of JKSFC was analyzed with different tools like trend analysis and ratio analysis and average growth rate. The results of the study show that performance of JKSFC is declining during the research period due tofacing problems of liquidity & solvency.


DEPIK ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 207-210
Author(s):  
Riyadi Subur ◽  
Muhammad Irfan ◽  
Nebuchadnezzar Akbar

NPK is a type of fertilizer that plays a role in increasing growth and survival in plants such as seaweed. This study aims to determine the effect of different NPK fertilizer doses on the growth rate of seaweed (Caulerpa racemosa), and to determine which NPK fertilizer dosage has the best effect on the growth rate of C. racemosa. Research begins with collecting samples of seaweed in coastal waters. Ternate Island District Kastela, and the cultivation process is carried out on Jalan Jan, Tabona Village, South Ternate City. The time of the research was two months from August to October, 2020. This study used 12 units of cool box in the form of cork with a size of 90 x 30 cm, which is used as a container for maintaining of C. racemosa. In each treatment using a seed weight of 50 grams. The NPK fertilizer dosage treatment tested was 4 doses, with 3 replications, namely: treatment A: 40 ml NPK fertilizer; B: 60 ml NPK fertilizer; C: 80 ml NPK fertilizer; D: 0 ml NPK fertilizer (control). Research containers using random placement. The design used was a completely randomized design (CRD), using analysis of variance (ANOVA). The results obtained showed that NPK fertilizer with different doses the effect is not significantly different on the growth rate of C. racemosa with the highest average growth rate in treatment C amounting to 8.725%, followed by treatment B of 8.178%, treatment A of 7.761%, and the lowest was treatment D of 6.519%.Keywords:NPKSeaweedCaulerpa racemosaGrowth rate


2020 ◽  
Vol 25 (2) ◽  
pp. 46
Author(s):  
Shekar Bose ◽  
Hussein Samh Al-Masroori ◽  
Salim Darwish Salim Al-Hasani

The dynamics of physical capital stock and net investment in artisanal fisheries of Al-Seeb - a coastal fishing town of Muscat Governorate are examined covering the period 2004-2013 . Data were gathered from two sources namely the Ministry of Agriculture and Fisheries and field survey. A hedonic regression model is used to examine the influence of boat characteristics on the boat acquisition prices and then to derive the growth rate of physical capital stock. Boat characteristics comprising of ‘age’, ‘horsepower (hp)’ and ‘length (vl)’ are found to be statistically significant at the 5% level and carry sign consistent with the economic theory of depreciation and cost respectively. While inter-annual fluctuation of net investment is observed, a positive trend in cumulative investment with an average growth rate of 7.63% is experienced in the fishery during 2004-2013. A crude assessment of the operating costs and the gross revenue of surveyed boat-owners in 2015 showed that on average monthly economic profit of 570.97±169.36SD OMR was received by individual boat-owner which complements the positive trend in cumulative investment.These findings have important management and policy implications in relation to the effective management of harvesting capacity as well as attract investment in the fishery. Finally, some limitations of the study are discussed along with the indication of potential future research.


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