The Solubility of Phosphogypsum and Recovery of Heavy and Radioactive Elements

2020 ◽  
Vol 38 (10A) ◽  
pp. 1470-1480
Author(s):  
Waleed T. Rashid ◽  
Israa A. Alkadir ◽  
Moayyed G. Jalhoom
Keyword(s):  
High Mobility ◽  
Major Elements ◽  
Radioactive Elements ◽  
Liquid Ratio ◽  
Phosphate Fertilizers ◽  
Negative Effect ◽  
Temperature Ranges ◽  
Solid Liquid ◽  
Positive Effect ◽  
Leaching Efficiency

The essential purpose of this paper is to illustrate and inspect the leaching characteristics of Iraqi Phosphogypsum (PG). The paper presents the results of the dissolution characteristics of heavy and radioactive elements from PG, which is a by-product result from the industry of phosphate fertilizers. Leachability of heavy and radioactive elements in deionized water that has been inspected under various states of leaching, including solid/liquid ratio (10, 20 and 50 /1g/L) and temperatures (25, 45 and 85 °C), with constant other parameters such as string speed (300 rpm) and contact time (60 minutes). For the most analysis elements, the progressive release of the metals, in addition to the major elements reflects high mobility.  The mobility of trace metals in PG has been generally classified into three main degrees: (1) high mobility elements such as Pb, Zn, Mn, and Cr; (2) moderate mobility elements such as Sr, V, Ba,Y,Hg, K and Ni; and (3)l ow mobility elements like Ca,Cu,Fe, and Ag. The maximum concentrations of the most of the metals were attained from a leaching state of 10/1g/L. Regarding temperature, the experimental results revealed that the PG solubility to leaching out elements increases noticeably as the applied temperature ranges from 25 to 45 °C; after this degree, the leaching efficiency decreases. Chloride had a positive and negative effect on the solubility of phosphorus. Calcium chloride had an adverse effect on solubility and observed reduced solubility with increased chloride. While the positive effect of sodium and magnesium chloride was observed, the solubility...

scholarly journals AN EMPIRICAL CROSS-COUNTRY STUDY ON CONSUMERS’ ATTITUDE TOWARDS AUGMENTED REALITY ADVERTISING

2020 ◽  
Vol 8 (2) ◽  
pp. 1424-1454
Author(s):  
Ela Sibel BAYRAK MEYDANOĞLU ◽  
Ahmet Mete ÇİLİNGİRTÜRK ◽  
Rıza ÖZTÜRK ◽  
Müge KLEIN
Keyword(s):  
Structural Equation ◽  
Perceived Value ◽  
Major Elements ◽  
Equation Modeling ◽  
Consumer Attitude ◽  
Research Model ◽  
Negative Effect ◽  
Survey Results ◽  
The Relationship ◽  
Positive Effect

The use of AR technology for advertising is becoming more and more popular. For the efficacy of AR ad campaigns, consumers' attitudes towards AR ads are decisive. One of the major elements that determines consumers’ attitudes towards advertising is the perceived value of the ad. The aim of this study is to analyze the relationship between AR ad value and consumer attitude and to investigate the factors that affect the perceived value of AR ads among the youth both in Turkey and Germany. The mentioned relations were represented in a research model developed in the study. It was proposed that informativeness, entertainment, novelty, interactivity and self-efficacy have a positive effect on advertising value while irritation and deceptiveness have a negative effect. It was also proposed that ad value affects consumers’ attitudes positively. To test the proposed hypotheses, online surveys were conducted among a group of 365 respondents in Germany and a group of 391 respondents in Turkey. The survey results were then tested by Structural Equation Modeling (SEM). Contrary to expectations, the proposed research model as a whole did not fit and the hypotheses were not supported for Turkish consumers. For German consumers the model was fitted and the hypotheses were supported.

scholarly journals Study on the Oxidative Leaching of Uranium from the Lignite in the CO32-/HCO3- System

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Y. Ning ◽  
Y. Li ◽  
Y. Zhang ◽  
P. Tang
Keyword(s):  
Yunnan Province ◽  
Reaction Model ◽  
Second Order Reaction ◽  
Liquid Ratio ◽  
Uranium Leaching ◽  
Pseudo Second Order ◽  
Oxidative Leaching ◽  
Solid Liquid ◽  
Leaching Efficiency ◽  
Alcoholic Hydroxyl

Na2CO3/NaHCO3 mixtures with different oxidants were used to leach uranium in the lignite which was obtained from Lincang, Yunnan province. The experimental results showed that the optimal solid/liquid ratio and CO32-/HCO3- ratio for uranium leaching were 1 : 20 (g/mL) and 2 : 1, respectively. With the increase of carbon concentration from 0.1 mol/L to 1.1 mol/L, the leaching efficiency of uranium increased from 14.64% to 42.39% after 6 h leaching. The oxidants could significantly enhance the uranium leaching efficiency, which was up to 72.23% by injecting O2 at 1.5 L/min after 12 h leaching. The oxidative leaching process of uranium from the lignite was better fitted to the pseudo-second-order reaction model. The sequential extraction results illustrated that the oxidants could effectively enhance the leaching of organic matter bound uranium in the lignite, which was decreased from 76.86 mg/kg to 9.00 mg/kg by injecting O2. The infrared spectrum analysis demonstrated that the corresponding transmittance at about 3197 cm−1 was prominently reduced after the oxidative leaching, which intimated that the phenolic and alcoholic hydroxyl might be the main functional groups combined with uranium in the lignite.

scholarly journals A hydrometallurgical process for the recovery of cerium from Khuren khad ore

2019 ◽  
pp. 32-37
Author(s):  
Sandagdorj N ◽  
Enerel B ◽  
Ching-Hwa Lee ◽  
Gankhuyag E ◽  
Terbish N
Keyword(s):  
Recovery Efficiency ◽  
Hydrometallurgical Process ◽  
Liquid Ratio ◽  
Precipitation Product ◽  
Solid Liquid ◽  
Leaching Efficiency

This study presents the recovery of cerium (Ce) from Khuren Khad ore by using the hydrometallurgical process. Several methods of leaching and precipitation were employed to investigate the recovery efficiency of Ce from the ore. According to the result, it is 4.8% of Ce contained in this ore sample. The best result of this study reveals that 100% Ce leaching efficiency can be obtained under leaching conditions of 6N HCl at a temperature of 70° C and 5g/50mL solid/liquid ratio and 3h. Further, 99.60% precipitation recovery of Ce was achieved with NaHCO3 at an interval of 24 hours. After leaching and precipitation, the concentration of Ce was enriched from 4.8% of Khuren Khad ore to 33.09% of precipitation product.

Extraction of Tungsten and Vanadium from the Spent SCR Catalyst by High Pressure Alkaline Leaching Method

2018 ◽  
Vol 913 ◽  
pp. 954-960 ◽  
Author(s):  
Jia Peng Chen ◽  
Li Wen Ma ◽  
Ming Xing Cao ◽  
Xiao Li Xi
Keyword(s):  
High Pressure ◽  
Catalytic Reduction ◽  
Sodium Hydroxide Solution ◽  
Liquid Ratio ◽  
Alkaline Leaching ◽  
Scr Catalyst ◽  
Solid Ratio ◽  
Alkali Leaching ◽  
Solid Liquid ◽  
Leaching Efficiency

Tungsten and vanadium are efficiently extracted from honeycomb-type spent selective catalytic reduction (SCR) catalyst by using a high pressure alkali leaching method. Theoretical thermodynamics calculation indicates that WO3and V2O5are soluble in sodium hydroxide solution, proving that the extraction of Wand V from the spent SCR catalyst by high pressure alkaline leaching is feasible. The effects of NaOH concentration, leaching temperature and time, liquid-solid ratio and stirring speed on leaching efficiency of W and V are systematically investigated. The leaching efficiency of W and V is 94.3% and 91.2%, respectively, under the optimal conditions: the NaOH concentration of 2mol/L, the leaching temperature 463.5 K, the reaction time 3 h, solid-liquid ratio 0.1 g/ml, the stirring speed of 400 r/min. The TiO2residue is in anatase crystalline phase.

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.

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