Reduction of NiO-Mn2O3 mixed oxides with hydrogen and its affecting by ionizing radiation

1980 ◽  
Vol 45 (6) ◽  
pp. 1754-1765 ◽  
Author(s):  
Milan Pospíšil ◽  
Jan Topinka
Keyword(s):  
Mixed Oxides ◽  
Morphological Changes ◽  
Reduction Rate ◽  
Inert Atmosphere ◽  
Fast Neutrons ◽  
Nickel Metal ◽  
Chemisorbed Oxygen ◽  
Negative Effect ◽  
Positive Effect ◽  
Complex Influence

Reduction of NiO-Mn2O3 mixed oxides with hydrogen was studied thermogravimetrically at 350-440°C; in the entire composition region, 0-100% of one component, total reduction with the formation of a heterogenous Ni-MnO system was observed. The character of the kinetic curves of reduction of Mn2O3 is affected by the way of preparation and heat treatment of the samples before their reduction in inert atmosphere. In the mixed oxide, nickel accelerates the reduction of manganese sesquioxide, proceeding via Mn3O4 intermediate product. The mutual interaction of the two components appears in the pronounced dependence of the reaction rate on the composition, correlable with the analogous dependence of the apparent activation energy of reduction. The extent of the interaction, morphological changes, and some physicochemical parameters depend upon the degree of dispersion of the two oxides, which is also a function of the composition. A prior irridation of the samples by gamma radiation, dose 8 . 105 Gy, or fast neutrons, fluency 6.8 . 1015 n/m2 (Dn = 28.1 Gy), brings about a substantial increase in the content of the chemisorbed oxygen, particularly in the range of excess Mn2O3. The gamma irradiation results in an acceleration of the reduction of the mixed oxides; the extent of this positive effect is a nonmonotonic function of the composition and depends markedly on the temperature. The complex influence of fast neutrons appears as a negative effect (lowering of the reduction rate) resulting from the destruction of the existing centres (the polishing effect); in dependence on the composition the effect inverts into a positive one on the generated and stabilized new centres, which affect the rate of nucleation of the nickel metal phase.

Effect of the ionizing radiation on the kinetics of the reduction by hydrogen of NiO-Fe2O3 mixed oxides of various genesis

1986 ◽  
Vol 51 (8) ◽  
pp. 1561-1570 ◽  
Author(s):  
Milan Pospíšil ◽  
Jan Topinka
Keyword(s):  
Radiation Effects ◽  
Mixed Oxides ◽  
Chemical Properties ◽  
Fast Neutrons ◽  
Chemisorbed Oxygen ◽  
First Case ◽  
Different Temperatures ◽  
Negative Effect ◽  
Order Of Magnitude ◽  
Kinetics Of

The kinetics of the reduction by hydrogen of two series of NiO-Fe2O3 mixed oxides of different composition was studied in the temperature range 320 - 410 °C using thermogravimetry. Both series were prepared from different precursors that were thermally decomposed at different temperatures. The oxidizing ability of the surface ( the content of chemisorbed oxygen) is the only parameter from all physico-chemical properties studied that changed significantly during the pre-irridation of the system by 60Co gamma radiation (dose 505 kGy), by fast neutrons from the 252Cf source (dose Dn = 110 Gy) and by accelerated electrons (3 MeV, dose 500 kGy). A positive radiation effect was observed in the first case while the irritation by neutrons and electrons resulted in a negative effect. The magnitude of the effect depends on the composition and genesis of the system and it decreases in the sequence γ, e-, n. The radiation induced changes in the reduction kinetics of mixed oxides change their magnitude and sign in dependence on the composition and genesis. Not only the increase by an order of magnitude of the rate of the initial phase of the reduction which was ascribed to the partial reduction of hematite to magnetite but also the acceleration of the second step (reduction of Fe3O4 to Fe) was observed after the exposure to photons or fast neutrons. The radiation changes induced by electrons are limited only to the surface of the irradiated solid and they affect only the first step of the reduction. The maximum positive effect was observed in the region of high excess of hematite and its magnitude decreases with the increasing content of nickel oxide. The radiation effects decrease with the increasing temperature of the reduction and at about 400 °C the effect of irradiation is completely annealed.

Effect of ionizing radiation on the kinetics of reduction of NiO-MgO mixed oxids with hydrogen

1979 ◽  
Vol 44 (4) ◽  
pp. 1023-1033 ◽  
Author(s):  
Milan Pospíšil ◽  
Miroslav Tvrzník
Keyword(s):  
Nickel Oxide ◽  
Magnesium Oxide ◽  
Reaction Rate ◽  
Mixed Oxides ◽  
Reduction Rate ◽  
Inert Atmosphere ◽  
Fast Neutrons ◽  
Mixed System ◽  
Degree Of Reduction ◽  
Kinetics Of

The low-temperature reduction of the mixed system nickel oxide-magnesium oxide with hydrogen was studied thermogravimetrically in the region 260-470 °C. The two oxides form in the whole composition region solid solutions, some physicochemical parameters of which vary nonmonotonically with the sample composition. The kinetics and degree of reduction of nickel oxide are appreciably affected by the presence of the unreduced magnesium oxide, in higher concentrations lowering the reaction rate. The kinetics of the reduction can be quantitatively described by the equation 1-(1-α)1/3 = kt, valid in dependence on the composition in differently wide ranges of the degree of reduction α. The reaction rate can be varied, particularly for samples with low contents of magnesium oxide, by heat treatment in inert atmosphere at 700 °C, and for all samples by irradiation by gamma rays or fast neutrons. The reduction rate grows with the increasing content of magnesium oxide up to a constant value. The positive effect increases with the increasing gamma dose and, according to the kind of radiation, in the order γ, n. The variation of the reactivity of irradiated or thermally treated mixed oxides is due predominantly to the shift of the equilibrium of the lattice defects, formation and stabilization of new centres, which affect the rate of nucleation of the forming metal phase.

Effect of Cement Raw Meal on the NO Reduction by Biomass Char

2020 ◽  
Vol 993 ◽  
pp. 1401-1406
Author(s):  
Nan Li ◽  
Su Ping Cui ◽  
Ya Li Wang ◽  
Xiao Yu Ma ◽  
Shi Jie Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
No Reduction ◽  
Fixed Bed ◽  
Reduction Rate ◽  
Laboratory Scale ◽  
Carbon Surface ◽  
Long Time ◽  
Negative Effect ◽  
Biomass Char ◽  
Positive Effect

The influence of cement raw meal on the NO reduction by biomass char at a high temperature of 900 °C with four O2 concentrations of 1%, 3%, 5% and 8% was investigated in a laboratory scale fixed bed quartz reactor. The results showed that the cement raw meal had certain positive effect on NO reduction by biomass char which promotes dissociation adsorption of NO with the help of CO consumption and oxygen transferred to carbon surface, however, it also shows some negative effect, and the degree depends on O2 concentration. A long-time and high NO reduction rate was obtained in the case of 1% O2 concentration.

Working Memory, Mental Prospection, Time Orientation, and Cognitive Insight

2013 ◽  
Vol 34 (3) ◽  
pp. 159-169 ◽  
Author(s):  
Sevtap Cinan ◽  
Aslı Doğan
Keyword(s):  
Working Memory ◽  
Structural Equation ◽  
Factor Model ◽  
Time Orientation ◽  
Equation Modeling ◽  
Cognitive Insight ◽  
Confirmatory Factor ◽  
Negative Effect ◽  
Positive Effect ◽  
Three Factor

This research is new in its attempt to take future time orientation, morningness orientation, and prospective memory as measures of mental prospection, and to examine a three-factor model that assumes working memory, mental prospection, and cognitive insight are independent but related higher-order cognitive constructs by using confirmatory factor analysis (CFA). The three-factor model produced a good fit to the data. An alternative one-factor model was tested and rejected. The results suggest that working memory and cognitive insight are distinguishable, related constructs, and that both are distinct from, but negatively associated with, mental prospection. In addition, structural equation modeling (SEM) showed that working memory had a strong positive effect on cognitive insight and a moderate negative effect on mental prospection.

Estimasi Pengaruh Faktor Internal Bank dan Stabilitas Makroekonomi terhadap Profitabilitas dengan Mediasi Rasio Pembiayaan Bermasalah di PT Bank Muamalat Indonesia

2020 ◽  
Vol 3 (2) ◽  
pp. 93-108
Author(s):  
Annisa Siti Fathonah ◽  
Dadang Hermawan
Keyword(s):  
Secondary Data ◽  
Financial Statements ◽  
Significant Positive Effect ◽  
Return On Assets ◽  
Internal Factors ◽  
Macroeconomic Factors ◽  
Operating Income ◽  
Significant Negative Effect ◽  
Negative Effect ◽  
Positive Effect

This study aims to determine and analyze how much influence the bank's internal factors such as Equity, Operational Costs per Operating Income (BOPO), Financing Deposit to Ratio (FDR), Non Performing Financing (NPF) as a mediator and external or macroeconomic factors namely inflation and Gross Domestic Product (GDP) on profitability represented by Return on Assets (ROA) at Bank Muamalat Indonesia for the period 2008-2018. The data used in this research are secondary data obtained from the publication of quarterly financial statements from 2008 to quarter 2 of 2018. The method that used in this research is path analysis with SPSS 20.0 as the analytical tool. The results of the study partially test the hypothesis (t-test), in substructure I shows that the capital variable has a significant negative effect on NPF, BOPO and inflation has a significant positive effect on NPF, FDR and GDP do not significantly influence NPF at Bank Muamalat Indonesia. In substructure II partially, Capital, BOPO, significant negative effect on ROA, FDR and NPF has a significant positive effect on ROA, Inflation and GDP does not significantly influence ROA while simultaneously significantly influencing ROA. Based on the sobel test, capital has a significant effect on ROA through NPF, BOPO has a significant effect on ROA through NPF, FDR has a significant effect on ROA through NPF, Inflation has a significant effect on ROA through NPF, while GDP has no significant effect on ROA through NPF.

Employee Engagement Dan Stress Kerja Pengaruhnya Terhadap Kepuasan Kerja Dan Turnover Intention di Aman Villas Nusa Dua – Bali

2020 ◽  
Vol 2 (1) ◽  
pp. 60-79
Author(s):  
Wayan Arya Paramarta ◽  
Ni Putu Kurnia Darmayanti
Keyword(s):  
Job Satisfaction ◽  
Employee Engagement ◽  
Work Stress ◽  
Turnover Intention ◽  
Secondary Data ◽  
Qualitative And Quantitative ◽  
Library Research ◽  
Analysis Technique ◽  
Negative Effect ◽  
Positive Effect

The aims of this study was to explain the effect of employee engagement and work stress on job satisfaction and turnover intention at Aman Villas Nusa Dua-Bali. The type of data used in this study is qualitative and quantitative data, with data sources namely primary and secondary data. Data collection method is interview, distributing questionnaires to respondents and library research, while the data analysis technique used Smart PLS 3.2.8. The results of this study showed that employee engagement had a positive effect and significant on job satisfaction, work stress had a negative effect but not significant on job satisfaction, employee engagement had a negative effect and significant on turnover intention, work stress had a positive effect and significant on turnover intention, job satisfaction had a negative effect but not significant on turnover intention, employee engagement had a positive effect but not significant on turnover intention trough job satisfaction, work stress had a positive effect but not significant on turnover intention trough job satisfaction at Aman Villas Nusa Dua-Bali.

The Factors Influencing Tourist Visitations Number in Curug Silawe

2019 ◽  
Vol 2 (3) ◽  
pp. 553-561
Author(s):  
Novian Hangga Prakosa ◽  
Fafurida Fafurida
Keyword(s):  
Economic Value ◽  
Consumer Surplus ◽  
Sampling Technique ◽  
Travel Cost ◽  
Analysis Tool ◽  
Literature Study ◽  
Factors Influencing ◽  
Negative Effect ◽  
Value Estimation ◽  
Positive Effect

The purposes of this research are to identify the influence of travel cost, income, distance, access, facilities, natural beautiness, and age on the number of individual visits to Curug Silawe and to estimate the economic value of Curug Silawe through individual travel cost method. The population in this study are tourists that visited Curug Silawe with sample of 98 respondents taken by the quota accidental sampling technique. The data collection method used are literature study and questionnaire. The analysis tool used are OLS linear regression and economic value estimation. The results showed the variables that influence the number of individual visits to Curug Silawe are income, distance and age. Income and age has a positive effect. While distance has a negative effect. The economic value of Curug Silawe reached IDR 1,109,930,140.48 per year. This value is obtained from consumer surplus obtained per individual per year of IDR 308,656.88. Tujuan dari penelitian ini adalah untuk mengidentifikasi pengaruh biaya perjalanan, pendapatan, jarak, akses, fasilitas, keindahan alam, dan usia pada jumlah kunjungan individu ke Curug Silawe dan untuk memperkirakan nilai ekonomi Curug Silawe melalui metode biaya perjalanan individu . Populasi dalam penelitian ini adalah wisatawan yang berkunjung ke Curug Silawe dengan sampel 98 responden yang diambil dengan teknik quota accidental sampling. Metode pengumpulan data yang digunakan adalah studi literatur dan kuesioner. Alat analisis yang digunakan adalah regresi linear OLS dan estimasi nilai ekonomi. Hasil penelitian menunjukkan variabel yang mempengaruhi jumlah kunjungan individu ke Curug Silawe adalah pendapatan, jarak dan usia. Penghasilan dan usia memiliki efek positif. Sedangkan jarak memiliki efek negatif. Nilai ekonomi Curug Silawe mencapai Rp1.109.930.140,48 per tahun. Nilai ini diperoleh dari surplus konsumen yang diperoleh per individu per tahun sebesar Rp308.656,88.

The depressing (negative) effect of oestradiol benzoate on the in vitro secretion of LH and FSH by the pituitary gland of the LRH-pretreated long-term ovariectomized rat changes into the augmentative (positive) effect after discontinuation of the LRH-pretreatment

1985 ◽  
Vol 110 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G. A. Schuiling ◽  
H. Moes ◽  
T. R. Koiter
Keyword(s):  
Depressing Effect ◽  
Ovx Rats ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate ◽  
Negative Effect ◽  
Positive Effect ◽  
Perifusion System

Abstract. The effect of pretreatment in vivo with oestradiol benzoate on in vitro secretion of LH and FSH was studied in long-term ovariectomized (OVX) rats both at the end of a 5-day continuous in vivo pretreatment with LRH and 4-days after cessation of such LRH pretreatment. Rats were on day 0 sc implanted with osmotic minipumps which released LRH at the rate of 250 ng/h. Control rats were implanted with a piece of silicone elastomer with the dimensions of a minipump. On days 2 and 4 the rats were injected with either 3 μg EB or with oil. On day 5 part of the rats were decapitated and the in vitro autonomous (i.e. non-LRH-stimulated) and 'supra-maximally' LRHstimulated release of LH and FSH was studied using a perifusion system. From other rats the minipumps were removed on day 5 and perifusion was performed on day 9. On the 5th day of the in vivo LRH pretreatment the pituitary LH/FSH stores were partially depleted; the pituitaries of the EB-treated rats more so than those of the oil-injected rats. EB alone had no significant effect on the content of the pituitary LH- and FSH stores. On day 9, i.e. 4 days after removal of the minipumps, the pituitary LH and FSH contents had increased in both the oil- and the EB injected rats, but had not yet recovered to control values. In rats not subjected to the 5-days pretreatment with LRH EB had a positive effect on the supra-maximally LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. EB had no effect on the non-stimulated secretion of FSH. After 5 days of in vivo pretreatment with LRH only, the in vitro non-stimulated and supra-maximally LRH-stimulated secretion of both LH and FSH were strongly impaired, the effect correlating well with the LRH-induced depletion of the pituitary LH/FSH stores. In such LRH-pretreated rats EB had on day 5 a negative effect on the (already depressed) LRH-stimulated secretion of LH (not on that of FSH). EB had no effect on the non-stimulated LH/FSH secretion. It could be demonstrated that the negative effect of the combined LRH/EB pretreatment was mainly due to the depressing effect of this treatment on the pituitary LH and FSH stores: the effect of oestradiol on the pituitary LRH-responsiveness (release as related to pituitary gonadotrophin content) remained positive. In LRH-pretreated rats, however, this positive effect of EB was smaller than in rats not pretreated with LRH. Four days after removal of the minipumps there was again a positive effect of EB on the LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. The positive effect of EB on the pituitary LRH-responsiveness was as strong as in rats which had not been exposed to exogenous LRH. The non-stimulated secretion of FSH was again not affected by EB. The results demonstrate that the effect of EB on the oestrogen-sensitive components of gonadotrophin secretion consists of two components: an effect on the pituitary LRH-responsiveness proper, and an effect on the pituitary LH/FSH stores. The magnitude of the effect of EB on the LRH-responsiveness is LRH dependent: it is very weak (almost zero) in LRH-pretreated rats, but strong in rats not exposed to LRH as well as in rats of which the LRH-pretreatment was stopped 4 days previously. Similarly, the effect of EB on the pituitary LH and FSH stores is LRH-dependent: in the absence of LRH, EB has no influence on the contents of these stores, but EB can potentiate the depleting effect of LRH on the LH/FSH-stores. Also this effect disappear after cessation of the LRH-pretreatment.

Pengaruh Etika Bisnis Islam Terhadap Kesejahteraan Pedagang (Studi Kasus Pedagang Pusat Pasar Medan)

2019 ◽  
Vol 4 (1) ◽  
pp. 185
Author(s):  
Ya’ti Ikhwani Nasution
Keyword(s):  
Free Will ◽  
Quantitative Research ◽  
Statistical Tools ◽  
Independent Variables ◽  
Islamic Business Ethics ◽  
Negative Effect ◽  
Data Collection Technique ◽  
Questionnaire Method ◽  
Market Center ◽  
Positive Effect

The purpose of this study is to find out whether there is an influence of Islamic business ethics with the variables of unity, equilibrium, free will, responsibility, benevolence and the welfare of traders in the Pusat Pasar Medan. This research is a quantitative research and the analysis used is multiple regression analysis. The data collection technique used is the questionnaire method obtained directly from the respondent, namely the Pusat Pasar Medan Trader. Analyzed using statistical tools, namely SPSS Version 22. Based on the results of data processing has shown that there is a significant influence as partially and simultaneously among the unity, equilibrium, free will, responsibility and benovelence towards the welfare of traders in the Medan Market Center. For unity, free will, responsibility and benovelence have a positive effect on the welfare of traders in Medan Market Center. While the equilibrium variable has a negative effect on the welfare of Medan Market Center traders. The adjusted R square value is 0.345. This means that 34.5% increase in welfare can be explained by independent variables, namely the variables of unity, equilibrium, free will, responsibility and kindness. While 65.5% is explained by other factors.

Pengaruh Likuiditas, Pertumbuhan Kredit, Efisiensi, dan Kecukupan Modal Terhadap Profitabilitas

2020 ◽  
Vol 1 (1) ◽  
pp. 27-35
Author(s):  
Lia Hendrawati ◽  
Said Djamaludin
Keyword(s):  
Stock Exchange ◽  
Growth Efficiency ◽  
Research Data ◽  
Capital Adequacy ◽  
Annual Data ◽  
Significant Positive Effect ◽  
Credit Growth ◽  
Negative Effect ◽  
Positive Effect ◽  
Observation Period

This study to examine and analyze the effect of liquidity, credit growth, efficiency, and capital adequacy on the Bank’s profitability listed on the IDX partially and simultaneously. The research data are annual data for the 5-year observation period (2009-2013). This research was conducted at 33 banks listed on Indonesia Stock Exchange. Banks Analyzed that met the population criteria were 23 banks. The analytical method used in multiple linier regression. The results showed that liquidity, credit growth, efficiency, and capital adequacy together (simultaneously) significantly influence profitability. Partially,  liquidity has a significant positive effect on profitability, while efficiency has a significant negative effect. Credit growth and capital adequacy have no significant effect on profitability. Liquidity is the variable that has the biggest effect on the Bank’s profitability. 

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