scholarly journals BDEsize: An R package for efficient determination of sample size in a balanced design of experiments

SoftwareX ◽  
2021 ◽  
Vol 16 ◽  
pp. 100837
Author(s):  
Jong-Hee Chung ◽  
Yong-Bin Lim ◽  
Donghoh Kim
Keyword(s):  
Design Of Experiments ◽  
Sample Size ◽  
R Package ◽  
Balanced Design

Development of HPLC Method for the Purity Test by Design of Experiments and Determination of Activation Energy of Hydrolytic Degradation Reactions of Sofosbuvir

2020 ◽  
Vol 16 (7) ◽  
pp. 976-987
Author(s):  
Jakub Petřík ◽  
Jakub Heřt ◽  
Pavel Řezanka ◽  
Filip Vymyslický ◽  
Michal Douša
Keyword(s):  
Activation Energy ◽  
Design Of Experiments ◽  
Mobile Phase ◽  
Hydrolytic Degradation ◽  
Isoconversional Method ◽  
Hplc Method ◽  
Organic Modifier ◽  
Calculation Methods ◽  
Degradation Reactions

Background: The present study was focused on the development of HPLC method for purity testing of sofosbuvir by the Design of Experiments and determination of the activation energy of hydrolytic degradation reactions of sofosbuvir using HPLC based on the kinetics of sofosbuvir degradation. Methods: Following four factors for the Design of Experiments were selected, stationary phase, an organic modifier of the mobile phase, column temperature and pH of the mobile phase. These factors were examined in two or three level experimental design using Modde 11.0 (Umetrics) software. The chromatographic parameters like resolution, USP tailing and discrimination factor were calculated and analysed by partial least squares. The chromatography was performed based on Design of Experiments results with the mobile phase containing ammonium phosphate buffer pH 2.5 and methanol as an organic modifier. Separation was achieved using gradient elution on XBridge BEH C8 at 50 °C and a flow rate of 0.8 mL/min. UV detection was performed at 220 nm. The activation energy of hydrolytic degradation reactions of sofosbuvir was evaluated using two different calculation methods. The first method is based on the slope of dependence of natural logarithm of the rate constant on inverted thermodynamic temperature and the second approach is the isoconversional method. Results and Conclusion: Calculated activation energies were 77.9 ± 1.1 kJ/mol for the first method and 79.5 ± 3.2 kJ/mol for the isoconversional method. The results can be considered to be identical, therefore both calculation methods are suitable for the determination of the activation energy of degradation reactions.

scholarly journals Software-guided microscale flow calorimeter for efficient acquisition of thermokinetic data

2021 ◽  
Author(s):  
Timothy Aljoscha Frede ◽  
Marlene Dietz ◽  
Norbert Kockmann
Keyword(s):  
Design Of Experiments ◽  
Process Development ◽  
Reaction Conditions ◽  
Experimental Conditions ◽  
Flow Calorimeter ◽  
Microscale Flow ◽  
Increased Sensitivity ◽  
Important Time ◽  
Optimal Reaction

AbstractFast chemical process development is inevitably linked to an optimized determination of thermokinetic data of chemical reactions. A miniaturized flow calorimeter enables increased sensitivity when examining small amounts of reactants in a short time compared to traditional batch equipment. Therefore, a methodology to determine optimal reaction conditions for calorimetric measurement experiments was developed and is presented in this contribution. Within the methodology, short-cut calculations are supplemented by computational fluid dynamics (CFD) simulations for a better representation of the hydrodynamics within the microreactor. This approach leads to the effective design of experiments. Unfavourable experimental conditions for kinetics experiments are determined in advance and therefore, need not to be considered during design of experiments. The methodology is tested for an instantaneous acid-base reaction. Good agreement of simulations was obtained with experimental data. Thus, the prediction of the hydrodynamics is enabled and the first steps towards a digital twin of the calorimeter are performed. The flow rates proposed by the methodology are tested for the determination of reaction enthalpy and showed that reasonable experimental settings resulted. Graphical abstract A methodology is suggested to evaluate optimal reaction conditions for efficientacquisition of kinetic data. The experimental design space is limited by thestepwise determination of important time scales based on specified input data.

Cryoscopy of Milk: Effect of Variations in the Method

1966 ◽  
Vol 49 (3) ◽  
pp. 511-515 ◽  
Author(s):  
R W Henningson
Keyword(s):  
Statistical Analysis ◽  
Sample Size ◽  
Freezing Point ◽  
Collaborative Study ◽  
Sample Temperature ◽  
Milk Samples ◽  
Two Samples ◽  
Temperature Rate

Abstract Bath level, sample temperature, rate of stirring, degree of supercooling, sample size, sample isolation, and refreezing of the sample were the variables in the thermistor cryoscopic method for the determination of the freezing point value of milk chosen for study. Freezing point values were determined for two samples of milk and two secondary salt standards utilizing eight combinations of the seven variables in two test patterns. The freezing point value of the salt standards ranged from –0.413 to –0.433°C and from –0.431 to –0.642°C. The freezing point values of the milk samples ranged from –0.502 to –0.544°C and from –0.518 to –0.550°C. Statistical analysis of the data showed that sample isolation was a poor procedure and that other variables produced changes in the freezing point value ranging from 0.001 to 0.011°C. It is recommended that specific directions be instituted for the thermistor cryoscopic method, 15.040–15.041, and that the method be subjected to a collaborative study.

scholarly journals Determination of the Sensitivity of a RapidEscherichia coli O157:H7 Assay for Testing 375-Gram Composite Samples

2000 ◽  
Vol 66 (9) ◽  
pp. 4149-4151 ◽  
Author(s):  
Wan-Ling Tsai ◽  
Cynthia E. Miller ◽  
Edward R. Richter
Keyword(s):  
Escherichia Coli ◽  
Sample Size ◽  
Ground Beef ◽  
Immunomagnetic Separation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa System ◽  
Composite Ground ◽  
Single Size ◽  
Composite Samples

ABSTRACT Both 25-g single-size ground beef samples and 375-g composite ground beef samples were tested by a method combining an immunomagnetic separation (IMS) technique with a sandwich enzyme-linked immunosorbent assay (ELISA) system (IMS-ELISA). The results demonstrated that IMS-ELISA could detect the target, Escherichia coliO157:H7, at the level of 10−1 CFU/g of sample in either the 25- or 375-g sample size.

scholarly journals Determination of Sample Size for Speed Measurement on Urban Arterials

2016 ◽  
Vol 17 ◽  
pp. 384-390 ◽  
Author(s):  
V. Varsha ◽  
Gaurav H. Pandey ◽  
K. Ramachandra Rao ◽  
B.K. Bindhu
Keyword(s):  
Sample Size ◽  
Speed Measurement ◽  
Urban Arterials

PENGARUH BUDAYA KERJA, KEPEMIMPINAN, DISIPLIN KERJA DAN KOMPENSASI TERHADAP KINERJA KARYAWAN PT. KAI DAOP 5 PURWOKERTO

2017 ◽  
Vol 3 (1) ◽  
pp. 87-100
Author(s):  
Karsono , ◽  
Denok Kurniasih ◽  
Dyah Retna Puspita
Keyword(s):  
Regression Analysis ◽  
Data Analysis ◽  
Sample Size ◽  
Multiple Regression Analysis ◽  
Compensation Effect ◽  
Employee Performance ◽  
Primary Data ◽  
Work Culture ◽  
Study Population

Abstract: Employee performance is very important for an organization to achieve its goals. This study aims to analyze the influence of work culture, on employee performance, leadership on employee performance, work discipline on employee performance, compensation on employee performance and work culture, leadership, work discipline, compensation on employee performance at PT. KAI Daop 5 Purwokerto. The study population is all employees of PT. KAI Daop 5 Purwokerto as many as 623 employees. Determination of sample size with Slovin formula obtained by 86 respondents. The data used is the primary data obtained from the questionnaires distributed to respondents.Tehnik data analysis used is a quantitative approach. The data of the research were analyzed using multiple regression analysis. The results showed that: Work culture affect the performance of employees means that if the work culture increases then the performance of employees will increase. Leadership affects the performance of employees means that if the existing leadership is conducive to work then the performance of employees will increase, work discipline does not affect the performance of employees means employees who discipline work high and employees who work discipline less have the same performance height, Compensation effect on the performance of meaning if the compensation increases then employee performance will increase, work culture, leadership, work discipline and compensation together affect the employee's performance, meaning that if work culture, leadership, work discipline and compensation together increase the employee performance will increase. Keywords: Working Culture, Leadership, Work Discipline, Compensation, Employee Performance. Abstrak: Kinerja pegawai merupakan hal yang sangat penting bagi organisasi untuk mencapai tujuannya. Penelitian ini bertujuan untuk menganalisis pengaruh budaya kerja, terhadap kinerja pegawai, kepemimpinan terhadap kinerja pegawai, disiplin kerja terhadap kinerja pegawai, kompensasi terhadap kinerja pegawai dan budaya kerja, kepemimpinan, disiplin kerja, kompensasi terhadap kinerja pegawai di PT. KAI Daop 5 Purwokerto. Populasi penelitian adalah semua karyawan PT. KAI Daop 5 Purwokerto sebanyak 623 orang karyawan. Penentuan ukuran sampel dengan rumus Slovin diperoleh sampel sebanyak 86 responden. Data yang digunakan adalah data primer yang diperoleh dari kuisioner yang dibagikan kepada responden.Tehnik analisis data yang digunakan adalah pendekatan kuantitatif. Data hasil penelitian dianalisis menggunakan analisis regresi berganda. Hasil penelitian menunjukkan bahwa: Budaya kerja berpengaruh terhadap kinerja pegawai artinya apabila budaya kerja meningkat maka kinerja karyawan akan meningkat. Kepemimpinan berpengaruh terhadap kinerja pegawai artinya apabila kepemimpinan yang ada sangat kondusif untuk bekerja maka kinerja karyawan akan meningkat, Disiplin kerja tidak berpengaruh terhadap kinerja pegawai artinya pegawai yang disiplin kerjanya tinggi dan pegawai yang disiplin kerjanya kurang memiliki kinerja yang sama tingginya, Kompensasi berpengaruh terhadap kinerja artinya apabila kompensasi meningkat maka kinerja karyawan akan meningkat, Budaya kerja, kepemimpinan, disiplin kerja dan kompensasi secara bersama-sama berpengaruh terhadap kinerja pegawai, artinya apabila budaya kerja, kepemimpinan, disiplin kerja dan kompensasi  secara bersama-sama mengalami peningkatan maka kinerja karyawan akan meningkat. Kata Kunci:  Budaya Kerja, Kepemimpinan, Disiplin Kerja, Kompensasi, Kinerja   Pegawai.

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