scholarly journals Optimization of lead (II) removal in leachates using Moringa oleifera seeds

2019 ◽  
Vol 268 ◽  
pp. 06011
Author(s):  
Mae Ann De Castro ◽  
Cyril Ann Agripa ◽  
John Raymond Barajas ◽  
Faye Taniegra
Keyword(s):  
Low Income ◽  
Moringa Oleifera ◽  
Primary Sources ◽  
Lead Removal ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Independent Variables ◽  
Comprehensive Programs ◽  
High Lead ◽  
Percent Removal

The absence of comprehensive programs in regulating release of lead to the environment in growing cities situated in developing countries results to widespread intrusion of lead bioaccumulation in their primary sources of food. As a result, a significant increase in lead related diseases continually grows in many low income regions. In an attempt to provide a means of minimizing lead bioaccumulation, we test the extent to which Moringaoleifera seeds (MOS) removes lead (II) ions in aqueous solution. A box-behnken experimental design was used to obtain the optimal conditions in the lead (II) removal process. MOS dosage, initial lead (II) concentration, and pH were found to have significant effects on the percent removal of lead (II) in solution. Actual values of these independent variables were chosen on the basis of preliminary experimental results. Optimum conditions were found to be: MOS dosage 10.0 g/L, initial lead (II) concentration 20.0 ppm, and pH at 5.5. Lead removal using MOS was also performed at optimal conditions. In conclusion, a high lead (II) removal using MOS strongly suggests its potential to be used as a means of treating liquids highly contaminated with lead.

scholarly journals Optimal conditions for the biological removal of arsenic by a novel halophilic archaea in different conditions and its process optimization

2013 ◽  
Vol 15 (2) ◽  
pp. 7-9 ◽  
Author(s):  
Mojtaba Taran ◽  
Mazyar Safari ◽  
Arina Monaza ◽  
Javad Zavar Reza ◽  
Salar Bakhtiyari
Keyword(s):  
Experimental Design ◽  
Halophilic Archaea ◽  
Taguchi Experimental Design ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Biological Removal ◽  
Arsenic Bioaccumulation ◽  
Removal Of Arsenic ◽  
Percent Removal ◽  
High Arsenic

Recently, concerns about arsenic have been increased due to its high acute toxicity to human and serious environmental problems. In this study, the ability of Halorcula sp. IRU1, a novel halophilic archaea isolated from Urmia lake, Iran for arsenic bioaccumulation was investigated and optimized by Taguchi experimental design. The optimum conditions for high arsenic bioaccumulation by Haloarcula sp. IRU1 could be achieved in the presence temperature 40oC, pH 8 and NaAsO2 at 90 mg/L. Under optimum conditions, the microorganism was able to perform their desired function with a 60.89 percent removal of arsenic. In conclusion, Haloarcula sp. IRU1 is resistant to arsenic and removes it in different conditions.

The technical and economic comparison of ethylene production from natural gas and ethane

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Farooq Abubakar Atiku ◽  
Vahid Pirouzfar ◽  
Chia-Hung Su ◽  
Sung-Yen Wei
Keyword(s):  
Natural Gas ◽  
Ethylene Production ◽  
Petrochemical Industry ◽  
Rate Of Return ◽  
Optimal Conditions ◽  
Economic Optimization ◽  
Optimum Conditions ◽  
Investment Cost ◽  
Significant Step ◽  
Economic Comparison

Abstract Ethylene is one of the most primary and widely used petrochemical products in today’s world and is considered as a chemical building block in the petrochemical industry. In this research, ethylene production from ethane and natural gas is evaluated in terms of cost and optimum conditions. Also, a comprehensive economic and technical comparison is made to achieve the optimal conditions for ethylene production concerning feed diversity. Nowadays most ethylene production units run with ethane feed. If it is possible to implement gas-ethylene processes with an inexpensive natural gas feed, it will be a significant step for technical and economic optimization. Thus, some methods are introduced and compared, and finally an economic review about best condition for ethylene production from ethane and natural gas/investment with regard to cost and economic efficiency of the methods is provided. The investment cost for Gas to Ethylene (GTE) and Ethane to Ethylene (ETE) processes is 363–701 million dollars per year, respectively. Also, rate of return (ROR) of 24 and 19% is calculated for GTE and ETE processes, respectively.

scholarly journals Enzyme optimization to reduce the viscosity of pitanga (Eugenia uniflora L.) juice

2016 ◽  
Vol 19 (0) ◽  
Author(s):  
Ricardo Schmitz Ongaratto ◽  
Luiz Antonio Viotto
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Incubation Time ◽  
Regression Models ◽  
Incubation Temperature ◽  
Correlation Coefficients ◽  
Enzyme Concentration ◽  
Optimum Conditions ◽  
Activity Time ◽  
Independent Variables

Summary The aim of this work was to separately evaluate the effects of pectinase and cellulase on the viscosity of pitanga juice, and determine the optimum conditions for their use employing response surface methodology. The independent variables were pectinase concentration (0-2.0 mg.g–1) and cellulase concentration (0-1.0 mg.g–1), activity time (10-110 min) and incubation temperature (23.2-56.8 °C). The use of pectinase and cellulase reduced the viscosity by about 15% and 25%, respectively. The results showed that enzyme concentration was the most important factor followed by activity time, and for the application of cellulase the incubation temperature had a significant effect too. The regression models showed correlation coefficients (R2) near to 0.90. The pectinase application conditions that led to the lowest viscosity were: concentration of 1.7 mg.g–1, incubation temperature of 37.6 °C and incubation time of 80 minutes, while for cellulase the values were: concentration of 1.0 mg.g-1, temperature range of 25 °C to 35 °C and incubation time of 110 minutes.

Kaempferol Extraction from Cuscuta reflexa using Supercritical Carbon Dioxide and Separation of Kaempferol from the Extracts

2011 ◽  
Vol 7 (4) ◽  
Author(s):  
Pranabendu Mitra ◽  
Kyu -Seob Chang ◽  
Dae-Seok Yoo
Keyword(s):  
Supercritical Co2 ◽  
Extraction Process ◽  
Optimum Conditions ◽  
Supercritical Co2 Extraction ◽  
Independent Variables ◽  
Cuscuta Reflexa ◽  
Optimal Processing ◽  
Layer Chromatography ◽  
Temperature Time ◽  
Central Composite

Kaempferol, a strong antioxidant, was extracted from Cuscuta reflexa (a medicinal plant) using supercritical CO2 and separated using thin-layer chromatography, column chromatography and HPLC analysis. A rotatable central composite design was used to determine the influence of process variables and arrive at optimal processing conditions in the supercritical CO2 extraction process of kaempferol. The kaempferol yield was effectively modelled as a function of the independent variables (temperature, time and pressure). The kaempferol yield increased with the increasing of temperature and time and decreasing of pressure of the supercritical CO2 extraction process. The predicted kaempferol yield at the optimum point was 52.92 µg/g and the optimum conditions were 50.7°C for 132.6 min and 15.9 MPa.

scholarly journals Optimal Conditions For Production Acidic D-Xylanase By Aspergillus niger in Submerged Fermentation

2011 ◽  
Vol 5 (3) ◽  
pp. 14-21
Author(s):  
Muhamed Omar Abdulatif ◽  
Hyder H. Assmaeel ◽  
Raghad kadhim Obeid ◽  
Ayat Adnan Abbas
Keyword(s):  
Aspergillus Niger ◽  
Rice Husk ◽  
Enzyme Production ◽  
Inoculum Size ◽  
Optimal Conditions ◽  
Optimum Conditions ◽  
Xylanase Production ◽  
Primary Isolation ◽  
Optimum Ph ◽  
Optimum Period

he Xylanase producing strain Aspergillus niger was isolated from soil on potato dextrose agar in the presence of xylan as its first substrate for primary isolation, and then grown under liquid medium fermentation in the presence of crude xylan (rice husk) to produce D-Xylanase. the optimum conditions were determined as follows: the Optimum pH for xylanase production was found pH 5.0, xylanase was induced by xylan (rice husk) 0.1% and the production was (61.221 U/ml) and nitrogen source Yeast extract recorded highest enzyme production( 89.71 U/ml), and repressed by carbon source xylose the highest enzyme production (88.69 U/ml). The optimum temperature was 40°с for xylanase production was (35.15 U/ml), the optimum period after 7 days of incubation was (52.33 U/ml) ,the optimum substrate concentration 0.1% was (45.95 U/ml), and the optimum inoculum size was 1 x 106 (spore /ml) recorded (57.19 U/ml ).

scholarly journals Taguchi Optimization of Plasticisation Process for Glycerol and TEA Based Thermoplastic Mango Starch Biofilms

2021 ◽  
Author(s):  
Ernest Chiedoziam Agwamba ◽  
Lawal G. Hassan ◽  
Achor Muhammad ◽  
Abdullahi M. Sokoto ◽  
Eric N. Agwamba
Keyword(s):  
Young Modulus ◽  
Cost Effective ◽  
The Other ◽  
Response Factor ◽  
Optimum Conditions ◽  
Taguchi Optimization ◽  
Independent Variables ◽  
Main Effect ◽  
Independent Variable ◽  
Interaction Plot

Abstract This investigation involves study of independent variable that influences the Young modulus of thermoplastic mango starch (TPS) as dependent response factor. The experiment was design using the Taguchi orthogonal technique with four independent variables; plasticiser type; glycerol (G), and Triethanolamine-(TEA) (T), percentage plasticiser (40 and 120 %), percentage carboxymethyl cellulose-CMC (10 and 50 %), and concentration of HCl (0.05 and 0.15 M). The result of the main effect plots for mean indicated that the gTPS-CMC1 with 268.85a MPa is a better outcome compared to gTPS-CMC3 with 280.31a MPa, since no significance difference was observed due to less composition requirement of CMC for gTPS–CMC1, making it more cost effective to produced with better optimum conditions. The interaction plot of the independent variables showed that for plasticiser types; when glycerol (G) was utilised a higher young modulus is observed than TEA (T) and only interacts with TEA (T) at 0.015 M HCl; 10 % CMC gives a higher response compared to 50 % CMC and showed no interaction even as the other independent variables fluctuates, and similar effect was observed for percentage plasticiser. Study concluded that the predicted mean (young modulus) is substantially consistent with the experimental observation (R2 = 0.6283).

scholarly journals Extraction of Titanium from Low-Grade Ore with Different Leaching Agents in Autoclave

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 497
Author(s):  
Mario H. Rodriguez ◽  
Gustavo D. Rosales ◽  
Eliana G. Pinna ◽  
Fernando M. Tunez ◽  
Norman Toro
Keyword(s):  
Buenos Aires ◽  
Marked Effect ◽  
Primary Sources ◽  
Low Grade ◽  
Buenos Aires Province ◽  
Optimal Conditions ◽  
Liquid Ratio ◽  
Viable Option ◽  
Alternative Sources ◽  
Solid Liquid

The progressive depletion of primary sources to obtain metals has led to the search for alternative sources for their recovery. In the particular case of titanium, titaniferous sands are a viable option for obtaining this metal. This paper presents the results of the dissolution of titanium from titaniferous sands of Buenos Aires province (Argentina) in a laboratory autoclave (450 mL of capacity). The operating parameters studied were as follows: different acids (HF, H2SO4 and mixtures of these acids); leaching agent concentration, 5–20% v/v; temperature, 75–150 °C; time, 30–180 min; solid–liquid ratio, 0.9–3.6% w/v; stirring speed, 110–550 rpm. The obtained results indicate that the increase in the leaching agent(s) concentration, temperature and time of contact with the acid mixtures have a marked effect on the dissolution reaction of titanium. Optimal conditions to achieve 89% extraction of titanium were obtained by leaching at 123 °C, 330 rpm, 80 min and 1.8% w/v with a mixture of 15% HF (v/v) and 10% H2SO4 (v/v).

scholarly journals Optimization of microwave-assisted alkaline pre-treatment method for the cellulolytic fermentation of abaca stripping waste into glucose

2019 ◽  
Vol 268 ◽  
pp. 06012
Author(s):  
Glanelle Ivy Cea ◽  
Julius Ryan Manlangit ◽  
Marianne Reverente ◽  
John Raymond Barajas
Keyword(s):  
Microwave Power ◽  
Treatment Method ◽  
The Philippines ◽  
Optimum Conditions ◽  
Glucose Yield ◽  
Independent Variables ◽  
Precursor Material ◽  
Pre Treatment ◽  
Microwave Time ◽  
Export Product

Abaca fiber remains a vital export product that contributes primarily to the continuous economic growth of the Philippines. However, the voluminous amount of byproducts generated has consistently caused setbacks which often result to major losses to the growing abaca industry in the country. In an attempt to provide a practical solution to the emerging problem, we investigate the utilization of abaca stripping waste (ASW) as a precursor material to produce bioethanol. We test the extent of conversion of the hemicellulose-rich by product to glucose. A box-behnken experimental design was used to obtain the optimal conditions in the conversion process. Alkaline concentration (%), microwave power (W), and microwave time (min) were found to have significant influence on the glucose yield. Actual values of these independent variables were chosen on the basis of preliminary experimental results. Optimum conditions using ridge analysis were found to be: alkaline concentration 2.55%, microwave power 124.0 W, and microwave time at 1.0 min. Conversion to glucose was also performed at optimum conditions. In conclusion, a high glucose yield obtained which is suitable for bioethanol fermentation presents evidence encouraging the utilization of abaca stripping waste to produce high value products.

The Role of Collaboration in Integrated Programs Aimed at Supporting Underrepresented Student Success in STEM

2019 ◽  
Vol 64 (3) ◽  
pp. 325-348 ◽  
Author(s):  
Adrianna Kezar ◽  
Elizabeth Holcombe
Keyword(s):  
Student Success ◽  
Low Income ◽  
Underrepresented Minority ◽  
Policy And Practice ◽  
Underrepresented Minority Students ◽  
Implementation Challenges ◽  
Integrated Programs ◽  
Underrepresented Student Success ◽  
Comprehensive Programs

The persistent underrepresentation of low-income, first-generation, and underrepresented minority students among those who complete an undergraduate degree in science, technology, engineering, and mathematics remains an issue of concern in higher education. Scholars and practitioners have increasingly realized that more comprehensive supports are required, as opposed to the single-strategy interventions that have been popular for several decades. Such supports, also known as integrated or comprehensive programs, combine and align several interventions that are both curricular and cocurricular and require the work of both faculty members and student affairs staff to design and implement. Collaboration among these groups is crucial to the success of these programs. However, the actual role that collaboration plays in these new student success efforts is undertheorized and has not been examined empirically. In this article, we describe the role of collaboration in improving program design for comprehensive, integrated programs, and for overcoming policy and practice implementation challenges.

Endocrine therapy use among Medicaid-insured breast cancer survivors with hormone receptor-positive tumors.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 6017-6017 ◽  
Author(s):  
Racquel Elizabeth Kohler ◽  
Stephanie B. Wheeler ◽  
Katherine Elizabeth Reeder-Hayes ◽  
Ravi K. Goyal ◽  
Kristen Hassmiller Lich ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Endocrine Therapy ◽  
Low Income ◽  
Breast Cancer Survivors ◽  
Symptom Burden ◽  
Control Program ◽  
Marginal Effect ◽  
Breast Cancers ◽  
Independent Variables ◽  
Co Morbidity

6017 Background: Estrogen receptor positive (ER+) and progesterone receptor positive (PR+) cancers account for the majority of breast cancer diagnoses and deaths. Among women with ER+ or PR+ breast cancers, endocrine therapy (ET) is the cornerstone of adjuvant therapy and reduces 5-year risk of recurrence by as much as 40%. Observational studies in Medicare and privately-insured populations suggest that ET is underutilized. We sought to characterize ET use in a low-income Medicaid-insured population in North Carolina. Methods: We used Medicaid claims data matched to NC Central Cancer Registry records for women ages 18-64 diagnosed with in situ, stage I or II breast cancer from 2003-2007. We excluded dual eligibles and included only cases enrolled in Medicaid for at least 12 of the 15 months following the index diagnosis. We defined our outcome as receipt of any ET medication (tamoxifen, letrozole, exemestane, or anastroxole) in prescription claims during the 15-month period post-diagnosis, among women with ER+ or PR+ disease. In multivariate logistic regressions, independent variables included age, race, tumor characteristics, receipt of other breast cancer treatments, co-morbidity, rural/urban residence, reason for Medicaid eligibility, involvement in the Breast and Cervical Cancer Control Program (BCCCP), patient-centered medical home enrollment, and diagnosis year. Results: Of the 269 women who met inclusion/exclusion criteria and were ER+ or PR+, only 45% filled a prescription for ET during the study period. In multivariate analyses, being involved in the CDC-affiliated BCCCP was significantly associated with higher likelihood of receipt of guideline-recommended endocrine therapy (Marginal Effect: 0.299, p<0.01), but other independent variables were not significantly correlated with receipt of ET. Conclusions: Results suggest that ET is substantially underutilized in this low-income, vulnerable population and that intervention efforts to improve ET use may be important. Qualitative research is needed to understand the more nuanced, behavioral reasons for ET underuse, which may be related to symptom burden, cost, and patient-provider communication.

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