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Design of Student and Course Learning Outcomes Measurement Kristianto, Hans; Prasetyo, Susiana; Susanti, Ratna Frida; Adithia, Mariskha Tri
JPI (Jurnal Pendidikan Indonesia) Vol 10, No 1 (2021)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Measurement of the outcomes becomes a vital part in OBE system to ensure the attainment of each outcome. In Indonesia, OBE was adopted in 2015 for higher education level. However, the changes were not accompanied with clear method to measure the outcomes, which became the urgency of this research. In this study, a preliminary method to measure student learning outcomes (SLO) and course learning outcomes (CLO) was presented. The measurement of SLO and CLO attainment was started by SLO mapping to courses, which usually had been done at curriculum design. Based on the mapping, formulation of CLO with a set of direct assessment was planned at the start of each course. After the teaching learning activities, a series of calculation was designed to obtain the attainment of SLO and CLO for each student, course, and whole study program. In the same time the final mark for GPA calculation of each student could also be obtained. The designed method could play an essential part in teaching-learning quality assurance and curriculum continuous improvement, which is aligned with both international and national accreditation criteria and standards. Furthermore, this study could provide insight for other study program in SLO and CLO attainment measurement.

KARAKTERISASI CARBON NANOSPHERES (CNSs) DARI MINYAK GORENG DENGAN KATALIS FERROCENE DI PERMUKAAN KARBON AKTIF Hans Kristianto; Cahyadi Dwi Putra; Arenst Andreas
Research Report - Engineering Science Vol. 2 (2015)
Publisher : Universitas Katolik Parahyangan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1275.875 KB)

Carbon nanospheres (CNSs) merupakan salah satu golongan nano karbon yang terbentuk sebagai produk samping dalam pembuatan carbon nanotubes (CNTs). CNSs memiliki ukuran antara 50 nm sampai 1 μm, dapat berupa bola kosong atau berisi. CNSs memiliki ikatan yang menggantung (dangling bonds) yang menyebabkan sifatnya reaktif. Dewasa ini CNSs banyak diteliti untuk dimanfaatkan sebagai support katalis, adsorbent, atau pun elektroda baterai dan superkapasitor.Pada penelitian ini, dilakukan sintesis CNSs dengan menggunakan support karbon aktif. Katalis yang digunakan adalah katalis besi yang berasal dari ferrocene, Fe(C5H5)2. Sementara itu minyak goreng digunakan sebagai sumber karbon pembentuk CNSs. Campuran minyak goreng, katalis, dan karbon aktif kemudian dikarbonisasi dengan menggunakan electrical furnace pada 700oC selama 1 jam dengan atmosfer nitrogen. Dalam percobaan ini divariasikan konsentrasi awal katalis 2,5, 5, 7,5 dan 10g katalis/100 ml minyak goreng, dengan rasio karbon aktif terhadap minyak goreng 1:3 (b/b). Karakterisasi produk menggunakan x-ray diffraction (XRD), analisa luas permukaan BET, Raman spektroskopi, energy dispersive X-ray spectroscopy (EDS), dan xray photoelectron spectroscopy (XPS). Morfologi permukaan karbon aktif diamati dengan scanning electron microscope (SEM) dan transmission electron microscopy (TEM).Hasil analisa SEM dan TEM menunjukkan bahwa dari sintesis yang dilakukan, terbentuk CNSs, yang tersusun atas C(002) dan C(100). Dapat diamati pula semakin besar katalis yang digunakan, semakin banyak CNSs yang terbentuk. Seiring peningkatan jumlah katalis, peningkatan kandungan besi dan oksigen di dalam sampel juga teramati dengan pengukuran EDS, akan tetapi berdasarkan analisa XPS, tidak ada perubahan komposisi gugus fungsi di permukaan karbon aktif. Penurunan luas permukaan karbon aktif teramati pada setiap sampel dengan penurunan maksimum 50%. Hal ini yang mengakibatkan penurunan kapasitas adsorpsi saat digunakan sebagai adsorbent. Saat sampel 2,5g/100mL diuji dengan cyclic voltammetry sebagai anoda baterai litium, performansinya stabil.Kata kunci: karbon aktif, katalis besi, minyak goreng, CNSs

Adsorpsi Ion Logam Kromium (Cr (Vi)) Menggunakan Karbon Aktif dari Bahan Baku Kulit Salak Selvya Utama; Hans Kristianto; Arenst Andreas
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2016: Prosiding SNTKK 2016
Publisher : Seminar Nasional Teknik Kimia Kejuangan

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Heavy metals are elements which are produced in industrial waste. This heavy metal waste causes pollution to the environment if the content of heavy metals contained therein exceeds the threshold. The toxic’s properties are extremely dangerous for humans if it accumulates in the human body. One of the heavy metals that are produced is chromium. Several chemical and biological methods to remove heavy metals contained in the waste have been found. The adsorption method is one of the efficient and effective ways to treat heavy metal waste. In this study, activated carbon was prepared from salacca peel. Effects of pH, adsorbent dosage and Cr(VI) concentration on the adsorption of hexavalent chromium were investigated. The results were analyzed with Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich adsorption isotherm models. And kinetic of the adsorption was performed based on pseudo first order, pseudo second order, and intraparticle diffusion equations. From the research, it is known that the optimum conditions for the Chromium(VI) adsorption occurs at pH 2. The adsorption capacity of salacca peel based activated carbons for the removal of hexavalent chromium was found to be 123 mg/g. And the best adsorption isotherm which can represent the adsorption equilibrium is Langmuir isotermal adsorption model. Moreover the data indicated that the adsorption kinetics follow the pseudo second order

Synthesis of Nano Silica Originated from Rice Husks using Sol Gel Method with Methanol as Solvent Daniel Yonathan; Hans Kristianto; Arenst Andreas
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2016: Prosiding SNTKK 2016
Publisher : Seminar Nasional Teknik Kimia Kejuangan

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Indonesia is an agricultural country that largely livelihood of the population in plants that produce carbohydrates such as rice, corn. Of the amount of rice produced there abundant agricultural waste. Agricultural wastes are utilized in this study is rice husk. In the rice husks are fairly large silica content is 16-18%. The purpose of this study for the synthesis nano silica from rice husk with the formation of silica phases and stages of formation nano silica. Silica formation stage was conducted using leaching and burning. While the formation stage nano silica conducted using sol gel + HCl 1M. Results are examined is the influence of solvent and aging time on the purity and characteristics nano silica. At this stage of the formation of silica, the leaching process using citric acid and burning at a temperature of 7500C for 5 hours resulted in the structure of amorphous silica and silica purity reached 93.08%. At this stage of formation nano silica with sol gel method using a variation of methanol and aging time. Variations solvent used is 1: 9, 1:16 and 1:19. While variations of aging time used is 1,3 and 6 days. Highest purity silica obtained by the method of sol gel variation of solvent 1: 9 and 1 day aging period at 75.45%. While the smallest nano-sized silica obtained by the sol gel method variation of solvent 1: 9 and aging time of 3 days with a size between 50-1500 nm

Sintesis Nanosilika dari Sekam Padi Menggunakan Metode Sol Gel dengan Pelarut Etanol Arenst Andreas; Hans Kristianto; Devi Fitriani Kurniawati
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2016: Prosiding SNTKK 2016
Publisher : Seminar Nasional Teknik Kimia Kejuangan

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Rice husk is a byproduct of the milling process of paddy into rice. Silica can be obtained from rice husk to be utilized in various fields in the industry into high value products, one of them is nanosilica. Nanosilica can be obtained from rice husk using sol gel method with ethanol solvent. Before using sol gel method, performed insulating silica from rice husk using leaching method with citric acid solvent and combustion method. The purpose of this research is to study the effects of feed ratio (sodium silica): solvent (ethanol) and aging time on sol-gel method on the physical characteristics and morphology of nanosilica. Variations were made in the sol-gel method consists of variations in the volume of sodium silica: ethanol is 1: 9, 1:16, and 1:23. Moreover, variations of aging time is 1, 3, and 7 days. Characteristics of nanosilica were analyzed using SEM (Scanning Electron Microscope) + EDX (Energy Dispersive X-Ray) and XRD (X-Ray Diffraction). At variations of ethanol solvent, the best variety is 1:16 for providing the highest purity silica (56.85%). While at the time variation of aging, aging time for 7 days giving highest silica purity results and the smallest size diameter.

Pemanfaatan Ekstrak Protein dari Kacang-kacangan sebagai Koagulan Alami: Review Hans Kristianto; Susiana Prasetyo; Asaf Kleopas Sugih
Jurnal Rekayasa Proses Vol 13, No 2 (2019)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Coagulation and flocculation are commonly used in water and wastewater treatment. Inorganic coagulant such as alum (Al2(SO4)3), ferrous sulphate (FeSO4), and polyaluminium chloride (PAC) are commonly used. These coagulants are known for its effectiveness and simple operation procedure. However, there are some drawbacks such as reduction in pH, potential negative health effect when the treated water is consumed, and large sludge volume. To overcome these problems, utilization of natural coagulants has been proposed. Based on its active coagulating agent, natural coagulant could be divided as polyphenolic, polysaccharides, and protein. Protein from beans and seeds is commonly used as the source of active coagulating agent, due to its effectiveness, availability, and relatively simple pretreatment is needed. Usually the protein is extracted by using 0.5-1 M NaCl solution as globulin is the major protein fraction in beans.The extracted protein could act as cationic polymer to neutralize negatively charged colloids through adsorption-charge neutralization mechanism. Extracted protein could work effectively to treat turbid and waste water with lower cost compared to alum. However, most of existing studies are still focused on small – pilot scale utilization thus further explorations are still needed.A B S T R A KKoagulasi dan flokulasi merupakan proses yang umum digunakan dalam pengolahan air dan limbah cair. Pada umumnya digunakan koagulan seperti alum (Al2(SO4)3), ferro sulfat (FeSO4), dan polialuminium klorida (PAC). Selain efektif, koagulasi merupakan proses yang relatif sederhana dan mudah diterapkan. Akan tetapi koagulasi dengan koagulan anorganik memiliki beberapa kekurangan seperti menurunnya pH menjadi asam saat digunakan, potensi gangguan kesehatan jika air hasil pengolahan terkonsumsi, serta volume sludge yang dihasilkan relatif tinggi. Penggunaan koagulan alami menjadi alternatif dalam pengolahan air untuk mengatasi berbagai kekurangan tersebut. Berdasarkan bahan aktif koagulannya, koagulan alami dapat dibagi menjadi polifenol, polisakarida, dan protein. Protein dari kacang-kacangan merupakan salah satu sumber koagulan alami yang umum digunakan, karena selain efektif, kacang-kacangan mudah didapat, serta membutuhkan perlakuan yang relatif sederhana, meliputi pengeringan, pengecilan ukuran, ekstraksi, serta purifikasi. Proses ekstraksi kacang-kacangan pada umumnya menggunakan larutan garam NaCl dengan konsentrasi 0,5-1 M, dikarenakan fraksi protein dominan pada protein kacang-kacangan pada umumnya berupa globulin. Protein yang terekstrak berfungsi sebagai polimer kationik yang cocok digunakan untuk mengolah koloid yang bermuatan negatif melalui mekanisme adsorpsi-netralisasi muatan. Pemanfaatan ekstrak protein dapat bekerja efektif untuk mengolah kekeruhan dan air limbah, dengan biaya yang lebih rendah dibandingkan alum. Akan tetapi pemanfaatannya masih pada skala laboratorium-pilot, sehingga diperlukan pengembangan lebih lanjut untuk isolasi ekstrak serta aplikasinya pada skala industri.

Potensi Polisakarida dari Limbah Buah-buahan sebagai Koagulan Alami dalam Pengolahan Air dan Limbah Cair: Review Hans Kristianto; Angelica Jennifer; Asaf Kleopas Sugih; Susiana Prasetyo
Jurnal Rekayasa Proses Vol 14, No 2 (2020)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.57798

Nowadays, various studies related to utilization of biobased materials as natural coagulants have been explored. Based on the source, natural coagulants can be classified as animal, vegetable, or microbial based. Furthermore, based on the active ingredients, it can be classified as protein, polyphenols, and polysaccharides. Polysaccharides are abundant natural ingredients and are often found in plants or animals. In this study, we focused on polysaccharides, especially those from fruit waste, such as seeds and fruit peels. It is known that around 25-30% of the total weight of fruit is generally wasted, even though it contains phytochemicals and various active ingredients that can be utilized, especially as a natural coagulant. This review will focus on the use of pectin and starch from fruit waste as natural coagulants for water- wastewater treatment. Generally, pectin is commonly found in the skin of fruits as part of the cell wall structure, while starch is found in fruit seeds as food reserves. To be used as a natural coagulant, pectin or starch need to be extracted first. In particular, starch needs to be modified either physically or chemically. The coagulation mechanism of pectin and starch usually follows the interparticle bridging mechanism. The use of pectin and starch from fruit waste needs to be explored and further investigated, to substitute the use of chemical coagulants.Keywords: coagulation; fruit waste; natural coagulant; polysaccharidesA B S T R A KDewasa ini berbagai studi terkait pemanfaatan bahan alam sebagai koagulan alami telah banyak dieksplorasi. Berdasarkan sumbernya, koagulan alami dapat digolongkan berbasis hewani, nabati, maupun mikrobial, sementara berdasarkan bahan aktifnya dapat digolongkan sebagai protein, polifenol, dan polisakarida. Polisakarida merupakan bahan alam yang berlimpah dan seringkali dijumpai pada tumbuh-tumbuhan dan hewan. Pada kajian ini difokuskan pada polisakarida terutama yang berasal dari limbah buah-buahan yang tidak termanfaatkan, seperti biji dan kulit buah. Diketahui sekitar 25-30% dari total berat buah pada umumnya terbuang, padahal memiliki kandungan fitokimia dan berbagai bahan aktif yang dapat dimanfaatkan, salah satunya sebagai koagulan alami. Pada tinjauan ini akan difokuskan pada pemanfaatan pektin dan pati dari limbah buah-buahan sebagai koagulan alami untuk pengolahan air dan limbah cair. Secara umum pektin umum dijumpai pada bagian kulit buah-buahan sebagai bagian dari struktur dinding sel, sementara pati umum dijumpai pada biji buah-buahan sebagai cadangan makanan. Untuk dapat dimanfaatkan sebagai koagulan alami, pektin ataupun pati perlu diekstrak terlebih dahulu, dan pati secara khusus perlu dimodifikasi baik secara fisika maupun kimia. Secara umum mekanisme koagulasi oleh pektin dan pati mengikuti mekanisme interparticle bridging. Pemanfaatan pektin dan pati dari limbah buah-buahan perlu dieksplorasi dan diteliti lebih lanjut, agar dapat mensubstitusi penggunaan koagulan kimia secara komersial.Kata kunci: koagulasi; koagulan alami; limbah buah-buahan; polisakarida

Design of Student and Course Learning Outcomes Measurement Hans Kristianto; Susiana Prasetyo; Ratna Frida Susanti; Mariskha Tri Adithia
Jurnal Pendidikan Indonesia Vol 10 No 1 (2021)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Measurement of the outcomes becomes a vital part in OBE system to ensure the attainment of each outcome. In Indonesia, OBE was adopted in 2015 for higher education level. However, the changes were not accompanied with clear method to measure the outcomes, which became the urgency of this research. In this study, a preliminary method to measure student learning outcomes (SLO) and course learning outcomes (CLO) was presented. The measurement of SLO and CLO attainment was started by SLO mapping to courses, which usually had been done at curriculum design. Based on the mapping, formulation of CLO with a set of direct assessment was planned at the start of each course. After the teaching learning activities, a series of calculation was designed to obtain the attainment of SLO and CLO for each student, course, and whole study program. In the same time the final mark for GPA calculation of each student could also be obtained. The designed method could play an essential part in teaching-learning quality assurance and curriculum continuous improvement, which is aligned with both international and national accreditation criteria and standards. Furthermore, this study could provide insight for other study program in SLO and CLO attainment measurement.

REVIEW: SINTESIS KARBON AKTIF DENGAN MENGGUNAKAN AKTIVASI KIMIA ZnCL2 Hans Kristianto
JURNAL INTEGRASI PROSES VOLUME 6 NOMOR 3 JUNI 2017
Publisher : JURNAL INTEGRASI PROSES

Karbon aktif merupakan material karbon yang berpori dengan luas permukaan yang besar sehingga banyak digunakan untuk berbagai aplikasi. Karbon aktif dapat disintesis dari batu bara antrasit atau pun bituminous, akan tetapi penggunaan biomassa sebagai bahan baku karbon aktif semakin banyak diteliti. Secara umum, pembuatan karbon aktif terdiri atas karbonisasi dan aktivasi secara fisika atau pun kimia. Pada review ini dibahas proses aktivasi kimia dengan menggunakan agen aktivasi ZnCl2. Dalam proses aktivasi, ZnCl2 berfungsi menginhibisi pembentukan tar, serta mendorong terjadinya aromatisasi sehingga menghasilkan produk karbon aktif yang berpori. Rasio ZnCl2 terhadap biomassa dan temperatur karbonisasi merupakan variabel yang berpengaruh terhadap luas permukaan karbon aktif yang diperoleh, sementara waktu karbonisasi cenderung tidak berpengaruh. Penelitian terbaru banyak berfokus pada eksplorasi penggunaan berbagai biomassa, penggunaan gelombang mikro sebagai pemanasan alternatif, serta penggunaan agen aktivasi pembantu dalam aktivasi karbon aktif. Pengambilan kembali agen aktivasi juga perlu diteliti lebih lanjut untuk menjamin sisi ekonomis proses pembuatan karbon aktif dengan aktivasi kimia.

PENERAPAN MODEL PEMBELAJARAN BERBASIS MASALAH (PROBLEM BASED LEARNING ) DALAM MATA KULIAH MANAJEMEN LIMBAH B3 Hans Kristianto; Tedi Hudaya
JURNAL PENDIDIKAN SAINS UNIVERSITAS MUHAMMADIYAH SEMARANG Vol 6, No 2 (2018): JURNAL PENDIDIKAN SAINS (JPS)
Publisher : Pendidikan Kimia Unimus

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26714/jps.6.2.2018.41-47

Perubahan metode pembelajaran yang sebelumnya berpusat pada pengajar (teacher-centered learning) menjadi berpusat pada siswa (student-centered learning), menuntut penggunaan berbagai model pembelajaran yang inovatif. Dalam penelitian ini dipaparkan penerapan model pembelajaran berbasis masalah (problem based learning; PBL) dalam mata kuliah Manajemen Limbah Bahan Beracun dan Berbahaya (B3) di Program Studi Teknik Kimia UNPAR pada semester genap 2016/2017, dengan tujuan mengamati perubahan gaya belajar mahasiswa sebelum dan setelah pembelajaran dengan model PBL dengan menggunakan kuesioner Grasha. Selain itu mahasiswa diminta untuk mengisi kuesioner evaluasi pelaksanaan kegiatan pembelajaran. Teramati perubahan gaya belajar mahasiswa, yaitu pada menurunnya gaya belajar avoidant, kenaikan pada gaya belajar competitive dan collaborative. Sekalipun terlihat perubahan, hasil tersebut belum signifikan secara statistik. Hasil umpan balik dari mahasiswa peserta kuliah pun cukup positif, karena mahasiswa merasa lebih aktif, belajar bekerja dalam tim, dan berkomunikasi. Hasil-hasil positif yang ditunjukkan dalam penerapan model PBL pada mata kuliah ini membuka peluang untuk menerapkan model pembelajaran serupa pada berbagai mata kuliah lain.

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