Developing and Evaluating an Inquiry-Based Online Course with a Simulation Program of Complexometric Titration

Author(s):  
Li Liu ◽  
Yizhou Ling ◽  
Jing Yu ◽  
Qiang Fu
2012 ◽  
Vol 16 (3) ◽  
Author(s):  
Laurie P Dringus

This essay is written to present a prospective stance on how learning analytics, as a core evaluative approach, must help instructors uncover the important trends and evidence of quality learner data in the online course. A critique is presented of strategic and tactical issues of learning analytics. The approach to the critique is taken through the lens of questioning the current status of applying learning analytics to online courses. The goal of the discussion is twofold: (1) to inform online learning practitioners (e.g., instructors and administrators) of the potential of learning analytics in online courses and (2) to broaden discussion in the research community about the advancement of learning analytics in online learning. In recognizing the full potential of formalizing big data in online coures, the community must address this issue also in the context of the potentially "harmful" application of learning analytics.


2020 ◽  
Vol 86 (10) ◽  
pp. 18-22
Author(s):  
K. N. Vdovin ◽  
K. G. Pivovarova ◽  
N. A. Feoktistov ◽  
T. B. Ponamareva

Zinc sulfate is the main component in the composition of the acidic zinc plating electrolyte. Deviation in the electrolyte composition from the optimum content leads to destabilization of the electrolysis process and deteriorate the quality of the resulting zinc coating. The proper quality of a zinc coating obtained by galvanic deposition can be ensured only with timely monitoring and adjustment of the electrolyte composition. A technique of X-ray fluorescence determination of zinc (in terms of zinc sulfate) in an acidic zinc plating electrolyte is proposed. The study was carried out using an ARL Quant’X energy dispersive spectrometer (Thermo Fisher Scientific, USA) with a semiconductor silicon-lithium detector. The features of the spectrometer design are presented. The optimal parameters of excitation and detection of zinc radiation were specified when the electrolyte sample was diluted 1:1000. The ZnKα1 line was used as an analytical line. The plotted calibration graph is linear, the correlation coefficient being 0.999234. The results of zinc determination according to the developed method were compared with the data of the reference method of complexometric titration to prove the reliability of the procedure. The results are characterized by good convergence and accuracy. The proposed method of X-ray fluorescence zinc determination in a zinc plating electrolyte equals complexometric titration in the limiting capabilities and even exceeds the latter in terms of the simplicity of sample preparation and rapidity. The developed method of X-ray fluorescence determination of zinc is implemented in analysis of the electrolyte used in the continuous galvanizing unit at «METSERVIS LLC».


2019 ◽  
Vol 17 (1) ◽  
pp. 23
Author(s):  
Ivnaini Andesgur ◽  
Imam Suprayogi ◽  
Pipi Handrianti

Daerah Aliran Sungai (DAS) Siak termasuk DAS kritis khususnya bagian hilir, dimana terjadinya penurunan debit dan kulitas air sungai yang dipicu oleh meningkatnya aktivitas disepanjang aliran sungai yang didominasi oleh kegiatan perkebunan. Penelitian ini bertujuan untuk menganalisis daya tampung beban pencemaran BOD, COD dan TSS pada DAS Siak bagian hilir menggunakan metode WASP 7.3; dan menentukan besar reduksi beban pencemarannya. DAS Siak bagian hilir dibagi menjadi 14 segment kemudian dilakukan simulasi beban pencemaran parameter BOD, COD dan TSS pada masing-masing segment. Pada simulasi ini digunakan debit minimum yaitu sebesar 151 m3/dt dilanjutkan dengan mereduksi beban pencemarannya sebesar 75%, 50% dan 25% sampai sesuai dengan baku mutu air peruntukan kelas II.  Hasil Pemodelan WASP7.3 Daya Tampung Beban Pencemaran DAS Siak bagian hilir kabupaten Siak pada debit andalan minimum masing-masing untuk parameter BOD sebesar -68.877,82 kg/hari, COD sebesar -300.242,11 kg/hari dan TSS sebesar -169.065,78 kg/hari, dimana tanda minus (-) menandakan bahwa beban pencemar melebihi daya tampung sungai. Reduksi beban pencemar untuk parameter BOD sebesar 75%, COD sebesar 50%, dan TSS sebesar 25%. Parameter BOD merupakan parameter tertinggi dilakukan reduksi karena semua segment pada DAS Siak bagian hilir kabupaten Siak melebihi baku mutu peruntukkan kelas II. Kemampuan DAS Siak bagian hilir kabupaten Siak untuk menampung beban pencemar berdasarkan baku mutu peruntukkan kelas II setelah dilakukan reduksi masing-masing parameter pencemar adalah BOD 75% sebesar 12.134,95 kg/hari, COD 50% sebesar 12.958,94 kg/hari, dan TSS 25% sebesar 36.280,66 kg/hari.


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