bluuebunny/crossref_metadata_2025_split huggingface dataset:
Penggunaan limbah tempe dalam biodegradasi zat warna azo menggunakan bioreaktor membran aerob-anaerob
Authors: Komala Putri Sri , Effendi Agus Jatnika , Wenten IG , Wisjnuprapto W 
Published: March 2020

Tempeh waste is a form of waste that still has an economic value, due to its relatively high organic and nutrient content compared to yeast extract. In this research, tempeh waste was used as a co-substrate for the removal of azo dye from textile industry effluent using an aerobic-anaerobic membrane bioreactor. The bioreactor consists of a modified activated sludge process, i.e. a contact-stabilization process coupled with anoxic reactor and combined with an external ultrafiltration membrane to replace the sedimentation process in conventional activated sludge process. The feed consists of Remazol Black-5 azo dye at a concentration of 110-120 mg/L, and tempeh waste as an organic and nutrient source at 8-10% v/v concentration. An experiment was done to measure the effect of hydraulic retention time on dye removal, by varying the HRT in the contact tank at 1, 1.5, 2, 2.5, and 3 hours, and that of stabilization- and anoxic tanks kept constant at 4 and 3 hours. From the experiment a 41-51% removal of the dye and 46-65% removal of organic compounds were obtained. The highest dye and organic compound removal was obtained at a contact HRT of 2 hours, namely 51% of dye removal and 65% of organic removal efficiencies. An auto-oxidation process occurs in the contact tank, resulting in an increase in the dye concentration.Keywords: tempeh waste, membrane bioreactor, Hydraulic Retention Time (HRT), contact tank, azo dye. Abstrak Limbah tempe merupakan salah satu limbah yang masih memiliki nilai ekonomis, karena kandungan senyawa organik dan nutrien yang terdapat didalamnya masih relatif tinggi jika dibandingkan dengan yeast extract. Dalam penelitian ini limbah tempe digunakan sebagai ko-substrat untuk penyisihan zat warna azo dari industri tekstil dengan menggunakan bioreaktor membran aerob-anaerob. Bioreaktor terdiri dari modifikasi proses lumpur aktif yaitu proses kontak-stabilisasi yang dihubungkan dengan reaktor anoksik dan dikombinasikan dengan membran ultrafiltrasi secara eksternal. Umpan terdiri dari zat warna azo Remazol Black-5 pada konsentrasi 110-120 mg/L dan limbah tempe sebagai sumber organik dan nutrien dengan konsentrasi 8-10% v/v. Percobaan dilakukan untuk mengamati pengaruh waktu retensi hidrolik (hydraulic retention time, HRT) tangki kontak terhadap penyisihan warna dengan variasi HRT tangki kontak antara 1, 1½, 2, 2½ dan 3 jam, sedangkan tangki stabilisasi dan anoksik pada HRT konstan 4 dan 3 jam. Dari percobaan dihasilkan penyisihan warna berkisar antara 41-51% dan penyisihan senyawa organik antara 46-65%. Baik penyisihan warna maupun senyawa organik terbesar dihasilkan pada HRT kontak 2 jam yaitu 51% untuk penyisihan warna dan 65% untuk penyisihan senyawa organik. Pada tangki kontak terjadi autoksidasi yang menyebabkan kenaikan konsentrasi warna.Kata Kunci: limbah tempe, bioreaktor membran, waktu retensi hidrolik (HRT), tangki kontak, zat warna azo.
Improving performance of low pressure reverse osmosis systems by intermittent autoflushing
Authors: Widiasa I N , Sinaga N , Ariyanti D 
Published: March 2020

Improving performance of low pressure reverse osmosis systems by intermittent autoflushing Scaling formation on the membrane surface in the form of calcium carbonate, calcium sulphate, silica, and/or magnesium silicate is a main problem of the reverse osmosis (RO) application for upgrading low grade water. Scaling in RO system is generally controlled by softening the feed water, limiting the recovery and/or the addition of antiscalants which is impractical for household RO system. In this work, the feasibility of intermittent autoflushing to prevent scale formation in household RO systems was investigated. All experiments were carried out using commercially available RO membrane (CSM RE-1812LP) which operated for 6 hours under operating pressure 5 kg/cm2 and total recycle operating mode. Model solution of feed water contain CaCl2 and NaHCO3 were prepared to meet various LSI values in the range of 0 to 1.5. Duration and interval time of autoflush were in the range of 60 to 15 s and 5 to 60 min respectively. The results shown that the permeate flux of the system which operated using intermittent autoflushing relatively stable. It is emphasized that intermittent autoflushing may improve the performance of household reverse osmosis systems.Keywords: Autoflushing, scaling, physical cleaning, reverse osmosis Abstrak Pembentukan kerak (scaling) pada permukaan membran berupa kerak kalsium karbonat, kalsium sulfat, silika dan atau magnesium silikat merupakan permasalahan utama pada aplikasi sistem membran reverse osmosis (RO) pada proses pemurnian air. Scaling pada sistem RO umumnya dikontrol dengan melakukan pretreatment terhadap air umpan seperti softening, menambahkan zat antiscalant pada saat proses pemisahan serta membatasi tingkat recovery, dimana proses-proses tersebut tidak praktis apabila diaplikasikan pada sistem RO skala rumah tangga. Penelitian ini bertujuan untuk melihat kemungkinan metode intermittent autoflush dapat diaplikasikan untuk menghambat terjadinya scaling pada sistem RO skala rumah tangga. Penelitian ini dilakukan dengan menggunakan satu unit membran spiral wound jenis CSM RE-1812LP yang dioperasikan dengan tekanan operasi 5 kg/cm2 dan waktu operasi ± 6 jam. Larutan umpan sintesis dibuat dengan melarutkan CaCl2 dan NaHCO3 hingga nilai LSI mencapai kisaran 0-1,5. Durasi dan interval dari metode intermittent autoflush divariasikan pada kisaran 60-15 detik dan 5-60 menit. Hasil penelitian menunjukkan bahwa fluks permeat relatif stabil pada sistem RO yang menggunakan metode intermittent autoflush. Hal ini menandakan bahwa metode intermittent autoflush ini dimungkinkan untuk meningkatkan kinerja dari sistem RO skala rumah tangga.Kata Kunci: Autoflushing, scaling, physical cleaning, reverse osmosis
Dinamika tetes ekstraksi cair-cair sistem air-metil etil keton (mek)-heksan dalam kolom isian
Authors: Mirwan Agus , Ariono Danu 
Published: March 2020

Mass transfer process occurs as effect of contact between continuous phase from above and dispersed phase from underside column. With existence of size and type of packing in column, that caused interfacial area to become bigger and residence time more and older so that improvement of mass transfer process. The aim of this research is to observe drop dynamics or movement behavior of drop in which the drop diameter size grouped based on current regime deputizing with Reynolds Number (Re) and to study mass transfer liquid-liquid extraction in packed column based on drop diameter size influenced by flow rate and packing type. Observation of drop behavior is done by using length square column transparent so that visually drop dynamics can be observed and recorded at every segment of column height using digital camera. This research will be done by varying packing type and flow rate of the dispersed phase and continuous phase to know behavior of drop. The research will be done by using water–MEK (methyl ethyl ketone)–n-hexane system. The result of this research for packing type of sphere and raschig ring show that more and more big dispersed phase flow rate and height from under side column (distributor), hence drop is more and more small with number of which more and more many. This caused significant increase on overall mass transfer coefficient.Keywords: drop distribution, sphere, raschig ring, drop diameter Abstrak Proses perpindahan massa ekstraksi cair-cair dalam kolom isian terjadi akibat adanya kontak antara fase kontinu dan fase dispersi yang dialirkan secara berlawanan. Berbagai macam ukuran dan jenis isian yang digunakan dalam kolom, menyebabkan luas permukaan kontak menjadi lebih besar dan waktu kontak makin lama sehingga terjadi peningkatan proses perpindahan massa. Penelitian ini bertujuan mengamati dinamika pergerakan tetesan dengan cara mengelompokkan ukuran diameter tetesan berdasarkan pada rezim aliran yang diwakilkan dengan Bilangan Reynold (Re) dan mempelajari perpindahan massa pada ekstrasi cair-cair dalam kolom isian yang didasarkan ukuran diameter tetesan yang dipengaruhi laju alir dan jenis isian. Pengamatan perilaku tetesan dilakukan dengan menggunakan kolom persegi panjang yang transparan sehingga secara visual dinamikanya dapat diamati dan direkam pada tiap segmen ketinggian kolom menggunakan kamera digital. Percobaan dilakukan dengan menggunakan sistem air-MEK (metil etil keton)-n-heksan. Hasil penelitian untuk jenis isian bola padat dan raschig ring menunjukkan bahwa makin besar laju alir fase dispersi dan ketinggian dari bagian bawah (distributor), maka tetesannya makin kecil dengan jumlah yang makin banyak. Hal ini menyebabkan kenaikan yang signifikan terhadap koefisien perpindahan massa keseluruhan.Kata kunci: distribusi tetesan, bola, raschig ring, diameter tetesan.
Application of ionic liquids for separation of propyne from propylene: solubility and selectivity studies
Authors: Palgunadi Jelliarko , Indarto Antonius , Winoto Haryo , Kim Hoon Sik 
Published: March 2020

Separation or removal of propyne from propylene, generated by naptha cracking process, is one of the most important processes in petrochemical industries because ppm level of propyne contained in feed olefins can serve as catalyst poisons in the polymerization of olefins. Recently, room temperature ionic liquids (RTILs) were introduced as novel solvents for the separation of various gases and hydrocarbons. RTIL is a salt composed of unsymmetrical organic cation and organic/inorganic anion which melts at room temperature. Prior to the decision of material selection for the effective separation of propyne/propylene employing RTIL, solubility behaviors and selectivities of propyne and propylene in various RTILs were investigated. For the solubility of propyne and propylene in 1-R-3-methylimidazolium-based RTILs, solubility measurement, thermodynamic analysis, and computational calculation strongly imply that the solubility of propyne is controlled by a trade-off between a specific solute-solvent interaction (hydrogen bonding of propyne-anion) and non bonding interaction (solubility parameter). In contrast, the solubility of propylene seems to be much strongly dependent on non-bonding interaction (solubility parameter) closely related to the physical attractive forces as suggested by regular solution theory. Thus, to achieve high selectivity of propyne over propylene, a RTIL with smaller-size and stronger hydrogen bonding ability should be employed.Keywords: propyne, propylene, solubility, selectivity, ionic liquidsAbstrakPemisahan senyawa propuna dari propena, yang dihasilkan oleh proses fraksionasi nafta adalah salah satu proses yang paling penting dalam industri petrokimia. Kontaminan propuna yang terkandung dalam umpan olefin dapat menjadi racun katalis dalam proses polimerisasi olefin. Kini cairan ionik temperatur ruang (RTIL) diperkenalkan sebagai pelarut baru untuk pemisahan berbagai gas dan hidrokarbon. RTIL adalah garam yang terdiri dari kation organik dan anion organik/anorganik asimetrik yang meleleh pada suhu kamar. Pemilihan senyawa pelarut RTIL yang tepat untuk pemisahan propuna / propena akan dibahas dalam tulisan ini. Dalam proses pelarutan propuna dalam RTIL berbasis 1-R-3-metilimidazolium, pengukuran kelarutan, analisis termodinamika, dan pemodelan mengisyaratkan bahwa kelarutan propuna dikendalikan oleh kompromi antara interaksi spesifik solut-pelarut (ikatan hidrogen propuna-anion) dan interaksi tak mengikat (parameter kelarutan). Sebaliknya, kelarutan propena sangat bergantung pada interaksi tak mengikat (parameter kelarutan) yang erat hubungannya dengan ikatan fisik seperti dipaparkan dalam teori larutan biasa (regular solution theory). Dengan demikian, untuk mencapai selektivitas tinggi terhadap propuna dibandingkan dengan propena, disarankan untuk menggunakan senyawa RTIL dengan ukuran molekul lebih kecil yang memiliki ikatan hidrogen lebih kuat.Kata Kunci: propuna, propena, kelarutan, absorpsi, cairan ionik
Pemodelan dan simulasi reverse flow reactor untuk oksidasi katalitik metana: pengembangan prosedur operasi start-up
Authors: Budhi Yogi Wibisono , Kurniawan Teguh , Bindar Yazid 
Published: March 2020

Modeling and simulation of reverse flow reactor for the catalytic oxidation of methane: the development of start-up operating procedures In this modelling and simulation study, three operating procedures during start-up of lean methane (1%-v) oxidation in reverse flow reactor (RFR) have been investigated to get auto-thermal condition, high methane conversion, faster pseudo steady state, and low preheating energy requirement. The RFR model developed based on one-dimension pseudo-homogeneous model for mass balance and heterogeneous model for energy balance. Procedure 1 , the preheating was employed only on the catalyst zone, fails to conduct the auto-thermal reaction and to achieve high conversion. Procedure 2, the preheating was employed for inert and catalyst of left side only, able to achieve the auto-thermal up to switching time (ST) 230 s. Procedure 3, the preheating was employed along the reactor bed, achieve the auto-thermal condition up to ST 300 s. Procedure 2 and 3 achieved the pseudosteadystate at 1000 s for ST 200 s with total conversion during start-up are 95% and 99%. The conversion of Procedure 3 higher than Procedure 2, unfortunately the heat load of Procedure 3 two times higher than Procedure 2. Keywords: modelling and simulation, catalytic methane oxidation, start-up procedure, reverse flow reactor, switching timeAbstrakDi dalam studi pemodelan dan simulasi ini, berbagai prosedur operasi reverse flow reactor (RFR) selama start-up untuk oksidasi katalitik metana encer (1%-v) dikaji dengan target sistem beroperasi secara ototermal, konversi metana tinggi, waktu pencapaian kondisi tunak semu (pseudosteady state) cepat, dan beban panas rendah. Pemodelan reaktor didasarkan pada model satu dimensi dan pseudohomogeneous untuk neraca massa, serta heterogen untuk neraca energi. Pemanasan katalis saja pada awal reaksi (Prosedur 1) tidak dapat mencapai kondisi reaktor yang ototermal. Pemanasan katalis dan inert bagian kiri (Prosedur 2) mampu mencapai kondisi reaktor yang ototermal hingga switching time (ST) 230 detik. Pemanasan seluruh bagian reaktor pada awal reaksi (Prosedur 3) mampu mencapai kondisi reaktor yang ototermal pada ST paling lama 300 detik. Prosedur start-up 2 dan 3 untuk ST 200 detik sama-sama mencapai waktu pseudosteady state pada 1000 detik dengan konversi total selama start-up masing-masing 95% dan 99%. Meskipun Prosedur 3 memberikan konversi sedikit lebih tinggi daripada Prosedur 2, namun beban panas Prosedur 3 mencapai dua kali lebih besar daripada Prosedur 2.Kata kunci: emisi metana, pemodelan dan simulasi, prosedur start-up, reverse flow reactor, switching time.
Karakteristik luas permukaan karbon aktif dari ampas tebu dengan aktivasi kimia
Authors: Sudibandriyo Mahmud , Lydia L 
Published: March 2020

Surface area characterization of activated carbon from sugarcane baggase by chemical activationAdsorption is one the process with many applications in the industries such as in a separation or in gas storage. In this adsorption, adsorbent selection is the most important thing. One of the adsorbent most suitable for this process is activated carbon. Previous studies show that high surface area of activated carbon can be produced from sugarcane bagasse using activator ZnCl2. The research’s goal is to produce activated carbon from sugarcane bagasse and determine the effects of activator on the surface area of activated carbon produced. Activators used in this research are KOH and ZnCl2 with the mass ratio of activator/carbon are 1/1, 2/1 and 3/1. The results show that The highest surface area, 938,2 m2/g, is obtained by activation using KOH with mass ratio of activator/carbon 3/1, whereas the highest surface area by activation using ZnCl2 is 632 m2/g with mass ratio of activator/carbon 2/1. For comparison, preparation of activated carbon by physical activation is also done and the surface area is 293 m2/g.Keywords: Activated carbon, chemical activation, sugarcane bagasse, KOH, ZnCl2 Abstrak Adsorpsi merupakan salah satu proses yang banyak digunakan dalam industri baik dalam pemisahan maupun untuk penyimpanan gas. Pada proses adsorpsi ini, pemilihan adsorben merupakan hal yang sangat penting. Salah satu jenis adsorben yang sangat cocok untuk proses ini adalah karbon aktif. Penelusuran studi sebelumnya menunjukkan bahwa karbon aktif dengan luas permukaan yang cukup tinggi dapat dibuat dari ampas tebu dengan menggunakan aktivator ZnCl2. Penelitian ini bertujuan untuk menghasilkan karbon aktif dari ampas tebu dengan aktivasi kimia serta mengetahui pengaruh aktivator terhadap luas permukaan karbon aktif yang dihasilkan. Aktivator yang digunakan dalam penelitian ini adalah KOH dan ZnCl2 dengan rasio massa aktivator/massa karbon 1/1, 2/1, dan 3/1. Aktivasi dilakukan pada temperatur 700 oC selama 1 jam. Hasil penelitian menunjukkan bahwa luas permukaan tertinggi sebesar 938,2 m2/g diperoleh dengan aktivasi menggunakan KOH dengan rasio massa aktivator/massa arang 3/1, sedangkan aktivasi dengan menggunakan ZnCl2 diperoleh luas permukaan tertinggi sebesar 632 m2/g dengan rasio massa aktivator/massa arang 2/1. Sebagai pembanding, pada penelitian ini juga dilakukan pembuatan karbon aktif dengan metode aktivasi fisika dan diperoleh luas permukaan karbon aktif sebesar 293 m2/g.Kata kunci: Aktivasi kimia, ampas tebu, karbon aktif, KOH, ZnCl2
Simulasi aliran fluida pada proses enhanced coalbed methane
Authors: Pradewa Mohammad Resalto , Dewi Retno Gumilang , Siagian Ucok W.R. 
Published: March 2020

Fluid flow simulation on enhanched coalbed methane systemThe Enhanced Coalbed Methane (ECBM) process can be applied as a carbon capture and storage (CCS) technology for the mitigation of greenhouse gases emissions, by transferring CO2 emitted by stationary sources into ECBM field reservoirs. This CCS-ECBM integration is a novel technology that is aimed at reducing CO2 emission while simultaneously improving the energy supply security in Indonesia. This research studies the fluid flow in fractures/cleats in CBM reservoirs, which is a laminar flow under pressure gradient in accordance to Darcy's law. The objective of this research is to understand the mechanism of the integration between CCS and ECBM process via computer simulations. Gas components considered in the simulation include CH4 and CO2. Fluid flow variables in this research are permeability (k), porosity (ϕ), and gas saturation (S). Simulations are done using the FlexPDE version 5 software package. Simulation results indicate that all three variables influence the fluid flow mechanism in fractures/cleats during the injection of CO2 in ECBM process. Simulations which are run for 100 days predict that methane recovery is inversely proportional to porosity, with a recovery of 97.88% at a porosity of 0.017, and 37.16% at a porosity of 0.63.Keywords: greenhouse gases, CCS, ECBM, fractures, cleats Abstrak Proses Enhanced Coalbed Methane (ECBM) dapat diterapkan sebagai salah satu teknologi penangkapan dan penyimpanan karbon (Carbon Capture and Storage atau CCS) untuk mitigasi emisi gas rumah kaca, dengan cara menyalurkan CO2 dari sumber emisi stasioner ke dalam reservoir lapangan ECBM. Integrasi CCS-ECBM ini merupakan teknologi baru yang diharapkan mampu mengurangi emisi CO2 sekaligus meningkatkan ketahanan pasokan energi Indonesia. Penelitian ini mempelajari aliran fluida pada retakan (fractures/cleats) di dalam reservoir CBM yang merupakan aliran laminer di bawah gradien tekanan yang mengikuti hukum Darcy. Penelitian ini bertujuan memahami mekanisme integrasi CCS dengan proses ECBM melalui pendekatan simulasi komputer. Senyawa-senyawa yang ditinjau adalah CH4 dan CO2. Variabel-variabel aliran yang diperhitungkan dalam model mencakup permeabilitas (k), porositas (ϕ), dan saturasi gas (S). Simulasi dilakukan menggunakan perangkat lunak FlexPDE versi 5. Hasil simulasi menunjukkan bahwa mekanisme aliran dalam retakan dengan injeksi CO2 pada proses ECBM dipengaruhi oleh ketiga variabel yang ditinjau. Simulasi yang dijalankan selama 100 hari menunjukkan bahwa perolehan metana berbanding terbalik secara linier terhadap porositas, dengan perolehan sebesar 97,88% pada porositas 0,017 dan 37,16% pada porositas 0,63.Kata kunci: gas rumah kaca, CCS, ECBM, retakan, cleats
Too Smart
Authors: Sadowski Jathan 
Published: March 2020

Who benefits from smart technology? Whose interests are served when we trade our personal data for convenience and connectivity?
Smart technology is everywhere: smart umbrellas that light up when rain is in the forecast; smart cars that relieve drivers of the drudgery of driving; smart toothbrushes that send your dental hygiene details to the cloud. Nothing is safe from smartification. In Too Smart, Jathan Sadowski looks at the proliferation of smart stuff in our lives and asks whether the tradeoff—exchanging our personal data for convenience and connectivity—is worth it. Who benefits from smart technology?
Sadowski explains how data, once the purview of researchers and policy wonks, has become a form of capital. Smart technology, he argues, is driven by the dual imperatives of digital capitalism: extracting data from, and expanding control over, everything and everybody. He looks at three domains colonized by smart technologies' collection and control systems: the smart self, the smart home, and the smart city. The smart self involves more than self-tracking of steps walked and calories burned; it raises questions about what others do with our data and how they direct our behavior—whether or not we want them to. The smart home collects data about our habits that offer business a window into our domestic spaces. And the smart city, where these systems have space to grow, offers military-grade surveillance capabilities to local authorities.
Technology gets smart from our data. We may enjoy the conveniences we get in return (the refrigerator says we're out of milk!), but, Sadowski argues, smart technology advances the interests of corporate technocratic power—and will continue to do so unless we demand oversight and ownership of our data.
When Blood Breaks Down
Authors: Sekeres Mikkael A. 
Published: March 2020

A leading cancer specialist tells the compelling stories of three adult leukemia patients and their treatments, the disease itself, and the drugs developed to treat it.
When you are told that you have leukemia, your world stops. Your brain can't function. You are asked to make decisions about treatment almost immediately, when you are not in your right mind. And yet you pull yourself together and start asking questions. Beside you is your doctor, whose job it is to solve the awful puzzle of bone marrow gone wrong. The two of you are in it together. In When Blood Breaks Down, Mikkael Sekeres, a leading cancer specialist, takes readers on the journey that patient and doctor travel together.
Sekeres, who writes regularly for the Well section of the New York Times, tells the compelling stories of three people who receive diagnoses of adult leukemia within hours of each other: Joan, a 48-year-old surgical nurse, a caregiver who becomes a patient; David, a 68-year-old former factory worker who bows to his family's wishes and pursues the most aggressive treatment; and Sarah, a 36-year-old pregnant woman who must decide whether to undergo chemotherapy and put her fetus at risk. We join the intimacy of the conversations Sekeres has with his patients, and watch as he teaches trainees. Along the way, Sekeres also explores leukemia in its different forms and the development of drugs to treat it—describing, among many other fascinating details, the invention of the bone marrow transplant (first performed experimentally on beagles) and a treatment that targets the genetics of leukemia.

The lessons to be learned from leukemia, Sekeres shows, are not merely medical; they teach us about courage and grace and defying the odds.