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Kajian efek Mpemba pada pendinginan air keran yang awalnya dipanaskan secara infinitesimal Founda Noviani, Elisabeth Pratidhina; Setiawan, Arif; Dwandaru, Wipsar Sunu Brams
Jurnal Sains Dasar Vol 2, No 2 (2013): October 2013
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jsd.v2i2.3291

Abstract The purpose of this research is to know whether in the cooling process of tap water that is initially heated infinitesimally follow the Mpemba effect or not. The sample that is used in this research is tap water from a uniform source. The control variables are freezer temperature, the content of water, volume of water, and type of water. Two variations are done on the sample, i.e. the water is initially heated infinitesimally and the water is not heated. Both samples are cooled together in a freezer. For some period of time their temperature is measured. The experiment is repeated nine times. Based on the analysis, water that is initially heated infinitesimally takes shorter time to reach zero centigrade than water that is initially unheated. The cooling graph of water that is initially heated infinitesimally intersects the cooling graph of water that is initially unheated. The intersection lies between 5.5oC until 26.5o C. From all parameters that are obtained from the data analysis, it can be concluded that the Mpemba effect occurs consistently in the cooling process of tap water that is initially heated infinitesimally. Key words: Mpemba effect, freezing, tap water, infinitesimal heating, cooling, time

Kajian Mekanisme Jalur Andong-Becak-Sepeda dalam Rangka Meningkatkan Sektor Kepariwisataan Kawasan Pusat Kota Yogyakarta Wipsar Sunu Brams Dwandaru
Jurnal Ilmiah WUNY Majalah WUNY XVIII Nomor 1, Februari 2016
Publisher : Universitas Negeri Yogyakarta

Indonesia merupakan salah satu negara berkembang yang saat ini sedang berusaha untuk meningkatkan kualitas bangsa, baik dari segi sumber daya alam maupun sumber daya manusianya. Seiring berjalannya waktu, peningkatan kualitas bangsa juga mendorong semakin meningkatnya mobilitas manusia yang akhirnya berakibat semakin diperlukannya alat transportasi. Saat ini, hampir setiap orang memiliki kendaraan pribadi karena tidak memadainya transportasi publik. Banyak pula dijumpai rumah-rumah penduduk yang memiliki lebih dari satu kendaraan, sehingga jumlah kendaraan yang semakin banyak menyebabkan semakin besarnya resiko kemacetan di jalan.

TOWARDS STUDYING NON-EQUILIBRIUM STATISTICAL MECHANICS THROUGH DYNAMICAL DENSITY FUNCTIONAL THEORY Wipsar Sunu Brams Dwandaru
Jurnal Sains Dasar Vol 2, No 1 (2013): April 2013
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Abstract In this brief article, the extension of density functional theory for non-equilibrium systems is presented. Density functional theory is a powerful framework in order to study the static properties of electronic systems via a variational principle whereby the density (varies in 3 dimension space) holds a key role instead of the many-body wave function. Evans (Adv. Phys., 1979) fully realized the importance of this and extended the theory for inhomogeneous fluid systems. Then in an urgent need to extend the theory for dynamical equilibrium or non-equilibrium systems, comes dynamical density functional theory. Here, the idea behind dynamical density functional theory is given based on the Smoluchowski equation. Keywords: density functional theory, non-equilibrium systems, variational principle, Smoluchowski equation

SIMULATION ANALYSIS OF THE TOTALLY ASYMETRIC SIMPLE EXCLUSION PROCESS TO DETERMINE THE PROFIL OF THE ONE-BODY CORRELATION FUNCTION, TWO-BODY CORRELATION FUNCTION, AND THREE-BODY CORRELATION FUNCTION AROUND THE ENDS OF THE LATTICE WITH LATTICE NUMBER VARIATION R. A. Adipurno; Wipsar Sunu Brams Dwandaru; Denny Darmawan; Bambang Ruwanto
Jurnal Sains Dasar Vol 4, No 1 (2015): April 2015
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

This study aimed to determine the behavior of one-body, two-body, and three-body correlation functions of the model dynamics TASEP with sequential updating rules and open boundary conditions on vehicular traffic around the end of the traffic light. The study began with the determination of algorithm to model the dynamics of TASEP and coding, with the variation of the input rate (α) , the output rate (β), and the number of lattice sites (N). Then the program run with specific time limit (t) and number of systems (M). The value of the one-body correlation function determines the average occupancy of particles in lattice site-i at time t. Two-body correlation function determines the average occupancy of particle at site-i when there is another particle occupying the nearest neighbor lattice, i+1, at time t. Three-body correlation function determines the average occupancy of particles to occupy lattice site-i when there are other particles occupying the nearest and next nearest neighbor lattice sites, i+1 and i+2, at time t. The value of the one-body correlation function turns out to be larger than the value of the two-body correlation function. The value of the two-body correlation function is larger than the value of the three-body correlation function for all phases. The correlation between a vehicle to another vehicle will be even greater. Keywords: TASEP, sequential updating, n-body correlation function

An extension of Gibbs variational principle for canonical partition function Elisabeth Pratidhina Founda Noviani; Wipsar Sunu Brams Dwandaru
Jurnal Sains Dasar Vol 2, No 1 (2013): April 2013
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Abstract A variational principle is derived based upon the canonical partition functions. This variational principle is obtained using the Gibbs variational principle. Firstly, the Gibbs variational principle is highlighted for the canonical ensemble. Then, the Gibbs variational principle is modified such that a variational principle concerning the partition function is obtained. The latter variational principle is useful as the canonical partition function is an important quantity in deriving many thermodynamic quantities of a physical system based upon the distribution of the constituents that makes up the system. Key words: variational principle, Gibbs variational principle, partition function

Preparation Nanomaterial Carbon Using The Liquid Mechanical Exfoliation by Linear Alkylbenzene Sulfonate with Variation Time of Mixing Ingreedients Preparasi Nanomaterial Karbon Menggunakan Metode Liquid Mechanical Exfoliation dibantu oleh Linear Alkylbenzene Sulfonate dengan Variasi Waktu Pencampuran Bahan PHATMA DIAN PRATIWI; Wipsar Sunu Brams Dwandaru
Jurnal Ilmu Fisika dan Terapannya (JIFTA) Vol 5, No 7 (2016): Jurnal Fisika
Publisher : Prodi Fisika, Departemen Pendidikan Fisika

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ABSTRAKPenelitian ini bertujuan (1) mengetahui besarnya Energi Gap pada hasil karakterisasi UV-Vis dengan variasi waktu (10 menit, 20 menit, dan 30 menit) pencampuran bahan antara LAS, air, dan graphite dari pensil 2B serta pencampuran bahan antara air dan graphite dari pensil 2B menggunakan metode LME (2) mengetahui struktur kristal dan parameter kisi pada hasil karakterisasi XRD dengan variasi waktu (10 menit, 20 menit, dan 30 menit) pencampuran bahan antara LAS, air, dan graphite dari pensil 2B serta pencampuran bahan antara air dan graphite dari pensil 2B menggunakan metode LME dan (3) mengetahui morfologi permukaan dan hasil komposisi kimia pada hasil karakterisasi SEM dan EDAX dengan variasi waktu (20 menit) pencampuran bahan antara LAS, air, dan graphite dari pensil 2B menggunakan metode LME.Sintesis graphene dengan LAS dan sintesis graphene tanpa LAS meggunakan metode LME. Variasi waktu pencampuran bahan yang digunakan adalah 10 menit, 20 menit, dan 30 menit dengan frekuensi blender tetap yaitu 36.89 Hz. Selanjutnya, dilakukan sentrifugasi dengan kecepatan 3000 rpm selama 20 menit sebanyak 12 kali. Karakterisasi yang dilakukan adalah karakterisasi menggunakan UV–Vis, XRD, SEM dan EDAX.Hasil penelitian dari karakterisasi spektrofotometer UV-Vis dengan variasi waktu pencampuran, menunjukkan bahwa semakin besar panjang gelombang, Eg yang dihasilkan semakin kecil. Hal ini sesuai dengan teori bahwa panjang gelombang berbanding terbalik dengan Eg. Pada karakterisasi XRD terhadap variasi waktu pencampuran muncul peak pada hasil difaktogram sinar-X. Munculnya peak menunjukkan bahwa graphene yang dihasilkan adalah kristal. Dan diketahui struktur kristal dari material tersebut adalah heksagonal dengan parameter kisi ɑ = 0,235686 nm dan c = 0,370314 nm. Hasil dari karakterisasi SEM dengan variasi waktu pencampuran 20 menit, diketahui morfologi dari sampel menghasilkan graphene berbentuk flakes, menyebar, dan bertumpuk -tumpuk, dengan ukuran (1.292 – 3.467) μm serta karakterisasi menggunakan EDAX menunjukkan presentase kandungan karbon sebesar 77.68% dan oksigen sebesar 17.27%.Kata Kunci: Nanomaterial, graphene, graphite, liquid mechanical exfoliation, linear alkylbenzene sulfonate, waktu pencampuran bahan.Jurnal Fisika UNY edisi Oktober 20162ABSTRACTThe objectives of the research are 1) know the Energy Gap’s outcome of UV-Vis characterization from mixing material between LAS, water, and graphite from 2B pencil along with mixing between water and graphite from 2B pencil using the LME method in some variation of time (10 minutes, 20 minutes, and 30 minutes), 2) know the crystal structure and the lattice parameters of XRD characterizing outcome from mixing material between of LAS, water, and graphite from 2B pencil along with mixing between water and graphite from 2B pencil with LME method in several variation of time (10 minutes, 20 minutes, and 30 minutes), and 3) know the surface morphology and result of chemical composition characterization outcome of SEM and EDAX from mixing between LAS, water, and graphite from 2B pencil using LME method on variation of time (20 minutes).The synthesis of graphene with LAS and the synthesis of graphene without LAS uses the LME method. Variation of mixing time materials are 10 minutes, 20 minutes, and 30 minutes with the frequency of blender is 36,89 Hz. Next, centrifugation at the speed of 3000 rpm for 20 minutes as many as 12 times. The characterization that used is UV-Vis, XRD, SEM, and EDAX characterization.The result of UV-Vis cauterization research in variation of mixing time, show that in the bigger wavelength, Eg that produced is less. This is accordance with the theory that wavelengths inversely to Eg. In XRD characterization to variation mixing time appear the peak from the result of x-rays difaktogram. This peak shown the graphene that produced was crystal. And the crystal structure is hexagonal with lattice parameter ɑ = 0,235686 nm and c = 0,370314 nm. The result of SEM characterization in variation of mixing time 20 minutes, shown that graphene that was flakes form, reams, and speard whit size (1.292 -3.467) μm, and the EDAX characterization shown the percentage of any carbon content is 77.68% and oxygen 17.27%.Keyword: nanomaterial, graphene, graphite, liquid mechanical exfoliation, linear alkylbenzene sulfonate, mixing time variation.

Optical Absorbance Study of Carbon Nanomaterials Synthesized from Used-cooking Oil via Liquid-phase Exfoliation Using a Kitchen Blender in n-Hexane Solution Lilis Misnawati; Wipsar Sunu Brams Dwandaru
Jurnal Ilmu Fisika dan Terapannya (JIFTA) Vol 6, No 3 (2017): Jurnal Fisika
Publisher : Prodi Fisika, Departemen Pendidikan Fisika

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Abstract. UV-Visual (UV-Vis) optical absorbance study in the synthesis of carbon nanomaterials produced from used-cooking oil via liquid-phase exfoliation (LE) using a kitchen blender which is dissolved in n-hexane solvent has been conducted. Here, the blending time duration and solution concentration are varied, i.e. (in hours) 1, 2, and 3, and (in milimol/mL) 0.2, 0.4, and 0.6, respectively. The solutions obtained from this study are characterized using UV-Vis spectrophotometer. The experiment is carried out by directly blending used-cooking oil and then dissolving it in n-hexane solvent. A solution of pure cooking oil in n-hexane is used as a reference solution for the UV-Vis spectrophotometer. For variation of blending time duration, the UV-Vis results show a blue shift from 269.5 nm to 235.5 nm as the blending time is increased from 1 to 3 hours and indicate the presence of graphene oxide (GO) material. A second absorbance peaks at around 349 nm to 351 nm correspond to the occurrence of carbon quantum dot (CQD) material. Moreover, for the variation of solution concentrations, a red shift from 311.5 nm to 350 nm occurs as the solution concentration is increased from 0.2 to 0.6 milimol/mL. The red shift point towards an exfoliation of used-cooking oil from GO into CQD materials.Keywords: graphene oxide, carbon quantum dot, UV-Vis spectroscopy, liquid-phase exfoliation, used-cooking oil, n-hexane.

PREPARASI DAN KARAKTERISASI NANOMATERIAL C-DOTS BERBAHAN LIMBAH CAIR BUDIDAYA LELE DENGAN METODE PEMANASAN OVEN Kartika Aulia Widyani; Wipsar Sunu Brams Dwandaru
Jurnal Ilmu Fisika dan Terapannya (JIFTA) Vol 8, No 2 (2021): Jurnal Fisika
Publisher : Prodi Fisika, Departemen Pendidikan Fisika

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Penelitian ini bertujuan untuk (1) preparasi nanomaterial C-dots limbah cair budidaya ikan lele dengan pemanasan oven, (2) karakteristik nanomaterial C-dots limbah cair budidaya ikan lele berdasarkan uji UV-Vis dan energi gap, (3) perbandingan volume limbah dengan massa serbuk limbah. Variasi waktu pemanasan oven data sampel yang digunakan, yaitu: 15 menit, 30 menit, 45 menit, 60 menit, 90 menit, dan 120 menit. Hasil sintesis C-dots dikarakterisasi menggunakan uji UV-Vis dan energi gap. Larutan yang diperoleh berwarna kuning-kecoklatan. Semakin lama pemanasan oven maka warna larutan semakin gelap. Selanjutnya, diperoleh perbandingan volume limbah cair dengan massa serbuk limbah sebesar 1 ml : 0,415 mg. Hasil uji UV-Vis menunjukkan puncak absorbansi pada panjang gelombang 298 nm, 209 nm, 345 nm, 306 nm, 283 nm, dan 368 nm. Selain itu, energi gap yang dihasilkan adalah 5,29915 eV; 4,32056 eV; 3,67953 eV; 4,8062 eV; 3,91167 eV; dan 3.81538 eV.Kata-Kata Kunci: C-dots, budidaya lele

PENGARUH VARIASI KONSENTRASI LARUTAN NANOPARTIKEL PERAK TEHADAP POROSITAS DAN KUAT TEKAN BATU BATA MERAH YANG DISISIPKAN LARUTAN NANOPARTIKEL PERAK / THE INFLUENCE OF VARIATIONS CONCENTRATION A SOLUTION SILVER NANOPARTICLES TO POROSITY AND COMPRESSIVE STRENGTH RED BRICKS WHICH MIXERED A SOLUTION SILVER NANOPARTICLES nosiyosa judenori; wipsar sunu brams Dwandaru
Jurnal Ilmu Fisika dan Terapannya (JIFTA) Vol 5, No 5 (2016): Jurnal Fisika
Publisher : Prodi Fisika, Departemen Pendidikan Fisika

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AbstrakTujuan dari penelitian ini adalah mengetahui karakterisasi panjang gelombang absorbansi nanopartikel perak dalam batu bata merah menggunakan uji UV-Vis, mengetahui kerapatan batu bata merah dilihat dari d (lebar kisi) melalui uji XRD, serta mengetahui pengaruh variasi konsentrasi larutan nanopartikel perak terhadap kuat tekan dan porositas pada batu bata merah. Penelitian ini menggunakan metode bottom-up, uji UV-Vis, uji XRD, uji porositas dan uji kuat tekan batu bata merah.Melalui uji UV-Vis dapat diketahui bahwa batu bata merah dengan penambahannanopartikel perak konsentrasi 2 mM masih mengandung nanopartikel perak dengan panjang gelombang sebesar 378,0 nm dan pada nilai absorbansi 1,081. Pada pengujian XRD dapat disimpulkan bahwa batu bata merah dengan penambahan nanopartikel perak konsentrasi 2 mM memiliki kerapatan lebih tinggi daripada batu bata merah tanpa penambahan nanopartikel perak yaitu pada sudut 26,43° dengan d (lebar kisi) sebesar 3.370 dan intensitas 558. Penambahan nanopartikel perak dengan konsentrasi 2 mM pada batu bata merah memberikan nilai kuat tekan paling besar yaitu 4,41 MPa dan nilai porositas paling rendah sebesar 19,65% dibandingkan batu bata merah tanpa penambahan nanopartikel perak. Kata kunci: nanopartikel perak, batu bata merah, spektrofotometer UV-Vis, XRD, kuat tekan, porositas.AbstractThe purpose of this research was to determine caracteristic wavelenght absorbance of silver nanoparticles in red bricks using UV-Vistests, knowing density of red brick seen from d (width of gird) through XRD tests and determine the effect of varying concentrations asolution silver nanoparticles of compressive strength and porosity the red bricks. This research use method bottom-up, UV-Vistests, XRDtests, porositytests, and compressive strengthtests of red bricks. Through UV-Vis test can know that red bricks with added silver nanoparticles concentration of 2 mM still determine silver nanoparticles with wavelenght is a 378,0 nm on value absorbance 1,081. At XRD testscan determine that red bricks with added silver nanoparticles concentration of 2 mM have density more high than red bricks without add silver nanoparticles that is on angle 26,43° with d (width of the gird) is a 3.370 and intensity 558. The addition of silver nanoparticles concentration of 2 mM in red bricksgiving the greatest value compressive strength is a 4,41 MPa and the value of the low porosity values is a 19,65% rather than red brick without added silver nanoparticles. Keywords: silver nanoparticles, red brick, spectrofotometer UV-Vis, XRD, compressive strength, porosity.

PENGARUH VARIASI SUHU PEMANASAN GERABAH DENGAN PENAMBAHAN NANOPARTIKEL PERAK TERHADAP UJI POROSITAS DAN KUAT TEKAN GERABAH THE EFFECT OF TEMPERATURE VARIATIONS EARTHENWARE WARMING WITH ADDITION SILVER NANOPARTICLE TOWARD EARTHENWARE POROSITY AND PRESSURE INTENSITY Yuwana Widada; Wipsar Sunu Brams Dwandaru
Jurnal Ilmu Fisika dan Terapannya (JIFTA) Vol 5, No 7 (2016): Jurnal Fisika
Publisher : Prodi Fisika, Departemen Pendidikan Fisika

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PENGARUH VARIASI SUHU PEMANASAN GERABAH DENGAN PENAMBAHAN NANOPARTIKEL PERAK TERHADAP UJI POROSITAS DAN KUAT TEKAN GERABAH Oleh :Yuwana Widada11306144001 ABSTRAK Penelitian ini bertujuan untuk 1) mengetahui karakteristik larutan nanopartikel perak menggunakan spektrofotometer UV-Vis, 2) mengetahui tingkat kerapatan patikel gerabah dengan penambahan larutan nanopartikel perak dan tanpa penambahan larutan nanopartikel perak menggunakan XRD, 3) mengetahui pengaruh variasi suhu pemanasan gerabah terhadap porositas dan kuat tekan gerabah dengan penambahan larutan nanopartikel perak dan tanpa penambahan larutan nanopartikel perak, dan 4) mengetahui suhu pemanasan yang baik untuk mendapatkan porositas dan kuat tekan gerabah dengan kualitas baik.Penelitian dimulai dengan membuat sintesis nanopartikel perak dengan konsentrasi 5 mM. Selanjutnya diuji menggunakan spektrofotometer UV-Vis. kemudian mencampur larutan nanopartikel perak pada gerabah kering yang telah dihaluskan dengan perbandingan 65% :35% dilanjutkan dengan proses pencetakan dan pemanasan dengan variasi suhu pemanasan 600°C, 700°C, 800°C, dan 900°C.Kemudian dilakukan uji porositas dan uji kuat tekan gerabah pada masing-masing sampel.Hasil penelitian menunjukkan adanya perbedaan karakteristik gerabah yang dibuat dengan nanopartikel perak dan tanpa nanopartikel perak. Pengujian UV-Vis pada nanopartikel perak menunjukkan absorbansi pada rentang panjang gelombang 420,40 nm – 457,80 nm. Pengujian XRD pada gerabah dengan nanopartikel perak menghasilkan jarak antar partikel 3,214 Ådan untuk gerabah tanpa nanopartikel perak menghasilkan jarak antar partikel3,242 Å. Gerabah dengan nanopartikel perak menghasilkan kerapatan partikel yang lebih rapat daripada gerabah tanpa nanopartikel perak. Hasil variasi suhu pemanasan gerabah menunjukkan suhu pemanasan yang baik untuk gerabah, yaitu pada suhu 600°C - 800°C. Kata kunci: nanopartikel perak, gerabah, porositas, kuat tekan. THE EFFECT OF TEMPERATURE VARIATIONSEARTHENWAREWARMING WITH ADDITION SILVER NANOPARTICLE TOWARDEARTHENWARE POROSITY AND PRESSURE INTENSITY By:YuwanaWidada11306144001 ABSTRACT The objectives of the research are 1) to know the characteristics of silver nanoparticles using SpectrophotometerUV-Vis, 2) to know the density level of particleearthenware with addition of silver nanoparticles and without addition of silver nanoparticles using XRD, 3) to know the effect of temperature variation warming earthenware towardearthenware porosity and pressure intesity with addition ofsilver nanoparticles and without additionof silver nanoparticles, and 4) to know the warming temperature was good to get the porosity and pressure intensity earthenware with good quality.This research is started by synthesis of silver nanoparticles with a concentration 5 mM. Further tested using UV-Vis.then mixing a solution of silver nanoparticles on dry earthenware that has been mashed with a ratio of 65%: 35% followed by the molding process and heating with temperature variation heating to 600°C, 700°C, 800°C and 900°C. Then test the porosity and pressure intesity on the earthenware of each sample.The results showed the differences in the characteristics of earthenware made with silver nanoparticles and without silver nanoparticles. UV-Vis absorbance of silver nanoparticles produced in the wavelength range of 420,40 nm – 457,80 nm. XRD testing to the earthenware with silver nanoparticles resulted the distance between particles 3,214 Å, and the earthenware without silver nanoparticles resulted the distance between particles 3,242 Å.Theearthenwarewith silver nanoparticles resulted the smaller density between particles than earthenware without silver nanoparticles.The results of the heating temperature variations of earthenware indicates the heating temperature was good for earthenware, which is at a temperature of 600°C - 800°C. Keywords: silver nanoparticle, earthenware, porosity, pressure intensity.

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