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Abstrak :
Limbah katalis nikel setiap tahun dihasilkan sekitar 1000 ton dimana kandungan nikel yang terdapat di dalam katalis sebanyak 16% wt. Berdasarkan hal diatas dalam penelitian ini ditujukan untuk mengambil kembali logam nikel dari limbah katalis nikel agar dapat dimanfaatkan kembali oleh perusahaan untuk dijual ke industri material. Metode yang digunakan dalam pengambilan kembali logam nikel dari limbah katalis adalah dengan metode leaching, ekstraksi cair-cair menggunakan ekstraktan selektif CYANEX 272 dan stripping. Hasil penelitian menunjukkan bahwa proses leaching limbah katalis nikel menggunakan H2SO4 mendapatkan nilai tertinggi pada konsentrasi 8 M dengan temperatur 85 oC dan waktu operasi sekitar 5 jam dengan persentase leaching nikel sebesar 97,23%. Pada proses ekstraksi dengan menggunakan Cyanex 272 dalam larutan kerosin, persentase ekstraksi yang optimum diperoleh sebesar 87,61% pada pH 7 dan konsentrasi Cyanex 0,6 M. ......Waste nickel catalyst produced each year around 1,000 tonnes with the nickel content present in the catalyst as much as 16% wt. Based on the above in this study is intended to retrieve a nickel of waste a nickel catalyst to be used again by the company to be sold to industrial materials. The method used in the recovery of nickel metal from the waste catalyst is the method of leaching, liquid-liquid extraction using a selective extractant CYANEX 272 and stripping. The results showed that the waste leaching process nickel catalyst using H2SO4 get the highest score at a concentration of 8 M with a temperature of 85 ° C and the operating time of about 5 hours with a percentage of 97.23% nickel leaching. In an extraction process using kerosene Cyanex 272 in solution, the optimum extraction percentage of 87.61% was obtained at pH 7 and Cyanex concentration of 0.6 M.

Abstrak :
Modifikasi elektroda busa nikel dengan NiCo2O4 hollow spheres (Ni-NiCo2O4) menggunakan template SiO2 komersil secara hidrotermal telah berhasil disintesis. Karakterisasi elektroda Ni-NiCo2O4 menggunakan SEM-EDS, TEM dan BET mengkonfirmasi adanya struktur hollow spheres NiCo2O4 dengan ukuran sphere berkisar 380 nm dan hollow 150 nm yang terbentuk pada pori-pori busa nikel dengan luas permukaan 17,944 m2/g. Evaluasi kinerja elektroda Ni-NiCo2O4 dengan teknik siklik voltametri pada larutan glukosa menunjukkan linieritas pada rentang konsentrasi 0,5-2,5 μM dengan nilai sensitivitas sebesar 23,97 mA.μM-1cm-2, batas deteksi (LOD) 0,12 μM, dan batas kuantifikasi (LOQ) 0,41 μM. Kestabilan yang tinggi diperoleh dengan nilai relative standard deviation (RSD) sebesar 1,51% pada 10 kali pengulangan. Uji selektivitas dengan adanya senyawa interferen berupa asam askorbat (AA) dan albumin menunjukkan bahwa konsentrasi interferen sampai dengan 50 persen analit tidak mempengaruhi performa sensor. Selain itu, uji validasi sensor pada deteksi glukosa dalam sampel plasma darah menunjukkan bahwa hasil deteksi tidak berbeda signifikan dengan analisis menggunakan glukodetektor. Hasil ini mengindikasikan bahwa sensor yang dikembangkan dapat diaplikasikan pada sampel nyata. ...... Modification of the nickel foam electrodes with hollow spheres NiCo2O4 (Ni- NiCo2O4) via hidrothermal using commercial SiO2 templates has been successfully synthesized. Characterization of electrodes Ni- NiCo2O4 using SEM-EDS, TEM and BET confirmed the existence of NiCo2O4 hollow spheres with sphere sizes around 380 nm and hollow around 150 nm, which formed in the nickel foam pores with a surface area of 17,944 m2/g. Evaluation of the performance of Ni-NiCo2O4 electrodes by using cyclic voltammetry technique in glucose solutions showed a good linearity in the concentration range of 0.5 - 2.5 μM with a sensitivity value of 23.97 mA.μM-1cm-2, detection limit (LOD) 0.12 μM, and the quantification limit (LOQ) of 0.41 μM. High stability could be obtained with a relative standard deviation (RSD) of 1.51% for 10 repetitive measurements. Selectivity testing in the presence of interferent compounds in the form of ascorbic acid (AA) and albumin also showed that interferent concentrations of up to 50 percent of analytes did not affect the sensor performance. In addition, validation of the sensor for glucose detection in blood plasma samples showed less significantly different in comparison with the test by using a glucodetector. The results indicated that the developed sensor is promising for real applications.

Abstrak :
Bruce Yoder’s thesis outlines his investigation of the dissociative chemisorption of methane (CH4) on a nickel single crystal. In this work Bruce uses a molecular beam and infrared laser techniques to prepare methane in excited rovibrational states. The excited methane molecules are aligned relative to the target nickel surface. Bruce describes the discovery and exploration of a previously unknown steric effect in the dissociation reaction between a vibrationally excited methane molecule and a nickel crystal. From these studies we see that methane molecules are up to twice as reactive when the vibration is aligned parallel rather than perpendicular to the surface. This discovery will help guide the development of detailed predictive models of methane chemisorption, which in turn may lead to better catalysts for the synthesis of several industrially relevant chemicals, including hydrogen fuel from natural gas.