bluuebunny/crossref_metadata_2025 huggingface dataset:
如何加强初中英语阅读教学
Authors: 郭 福兰
Published: October 2019

现阶段我国初中英语阅读教学存在的问题较多,改善英语阅读教学现状是当今英语教师面临的重大挑战。因此,英语教师应制定相关策略,创新英语阅读教学形式,进而推动学生英语综合能力的发展。
如何进行学生顶岗实习期间角色转变矛盾的化解——中职学生顶岗实习案例解析
Authors: 吴 征
Published: October 2019

中职学校为社会培养实用型的技术工人,如何把学校的学生转变为企业的员工是中职教育的核心目标。中职学生进行半年的顶岗实习,作为角色转变的过渡。于是在企业顶岗实习的学生就有了双重身份。如何处理在此期间学生、家长对于角色转变上的认识问题,是班主任对顶岗实习期间学生,进行教育管理的重要问题。
职业院校参与全国职业技能大赛对学生未来职业发展的影响
Authors: 鞠 鹏杰
Published: October 2019

随着教育的深化改革,全国职业技能大赛的开展对职业院校的学生来说有着至关重要的作用,参与职业技能大赛不仅能够锻炼学生实践操作的能力,还能够对学生未来的职业发展产生一定的影响。本人从一名全国职业技能大赛优秀指导老师的角度,在介绍学生职业能力与职业大赛的发展现状基础上,论述了职业技能大赛对学生未来职业发展的影响。希望能为该领域的研究起到一定的借鉴作用。
浅析技能大赛对高职教学的促进作用
Authors: 吴 春杨 , 冯 玉光
Published: October 2019

技能大赛的开展促进了教育事业的发展,主要表现在提升了高职教师的育人水平,加快了高职教学改革的进程,增加了毕业生就业的选择,也为企业筛选人才提拱了新的指标。
探究一体化课堂教学与微课程设计
Authors: 张 建如
Published: October 2019

目前,职业教育在我国得到了空前的重视和发展,而技术与教育共同的发展性价值也日益凸显。一体化教学在职业教育专业教学中的实施已经逐渐明确了课堂教学标准和教学设计的主要要素,评价标准也应建立在“以学生为中心”的评价理念上,而近年新兴的微课程理念也引起教师们的广泛关注。本文从一体化课堂教学设计应遵循的要素到微课程设计应考虑的维度开展研究分析,以寻求微课程设计的理念和特性。
近代犹太人在青岛生活状况研究
Authors: 齐 冬冬 , 刘 梦奇
Published: October 2019

在来华犹太人的研究中,鲜见关于犹太人在青岛的研究。本文根据所考的一手资料及部分二手资料对近代犹太人来青的背景、在青岛的分布、青岛犹太联合会旧址、青岛联合会活动内容,以及青岛不同年代政府对犹太人的政策和来青犹太人最终离开青岛的情况做简要介绍。论文共包括五个章节,第一章论述近代犹太人来青岛的背景,第二章介绍在青岛的犹太公会,第三章概述近代青岛政府对犹太人的政策,第四章考证了近代青岛地方报纸对犹太人的报道,最后一章是关于犹太人离开青岛的事宜。
基于符号学理论的现代家具设计研究
Authors: 陈 梦媛
Published: October 2019

为了满足人的各种需求,设计应运而生,设计是人与产品沟通的载体。在家具设计的领域中,现代家具的设计和开发是根据其背后深层的文化和理论支撑,从人们的需求着手,去了解人们的需求,提升更好的体验感。所以本文通过对符号学基本理论的阐述,探讨在现代家具设计中,符号学原理在其中的应用方法,把符号学理论运用于现代家具设计中。
Analisis Tipologi Wilayah Berdasarkan Pertumbuhan Ekonomi, Sektor Basis Dan Disparitas Pendapatan
Authors: Afandi Fajar , Jumiati Aisah , Adenan Moh.
Published: October 2019

Success Economic development in developing countries can be measured by high economic growth and income distribution. Many economic growth approaches are carried out in several regions in developing regional economic sectors which are expected to increase equity. The research methodology used is descriptive quantitative which explains the results of the calculation to see the condition of the area under study. The purpose of this paper is to determine the condition of regencies / cities in East Java Province based on economic growth, sector basis and the number of income disparities. Based on the results of the study showed that East Java Province was dominated by the quadrant IV category based on the Agriculture sector with a high rate of income disparity.
SINTESIS SURFAKTAN ALKIL POLIGLIKOSIDA DARI GLUKOSA DAN DODEKANOL DENGAN KATALIS ASAM
Authors: Anastasia Wulan Pratidina Swasono  , Putri Dei Elvarosa Sianturi  , Zuhrina Masyithah
Published: October 2019

Alkyl polyglicoside (APG) is an enviromentally friendly product  non-ionic surfactact and  biodegradable product that can be obtained by reacting glucose and fatty alcohol. The purpose of this study was to know the manufacture of surfactant alkyl polyglicoside by using glucose and dodecanol, and also to know the effect of catalyst concentration and molar ratio glucose  and dodecanol: 1:1; 1:2: 2:1 (mol/mol), catalyst consentration of hydrochloric acid: 0.3 M; 0,4 M; 0,5 M; 0,6 M at temperature 100 0C. The analysis in this research using FT-IR spectroscopy, analysis of surface tension (Critical Micelle Concentration) and HLB values ​​(Hidrophylic-Lipophylic Balance). The best catalyst concentration at synthesis of alkyl polyglicoside is 0.6 M, the largest surface tension (CMC) at ratio glucose and dodecanol 2:1 is 70.7945% and the highest HLB value is 7.31 in comparison of glucose and dodecanol 2:1.
PENENTUAN EFISIENSI INHIBISI REAKSI KOROSI BAJA MENGGUNAKAN EKSTRAK KULIT BUAH MANGGIS (Garcinia mangostana L)
Authors: Yuli Rizky Ananda Nasution  , Sri Hermawan  , Rosdanelli Hasibuan
Published: October 2019

Garcinia mangostana peel extract is a natural inhibitor that can be used to inhibit the corrosion reaction rate. This research begins by extracting Garcinia Mangostana pods by maceration followed by evaporation and extracts used as the inhibitor with concentration 600, 800 and 1000 ppm, with the test sample of corrosion is steel 1 × 2 cm with the thickness is 0,1 cm and corrosive medias are sea water, rain water and sulfuric acid 1 M. The highest inhibition efficiency generated is 99,22% with ethanol solvent at concentration of 800 ppm inhibitor in rain water corrosive media; which means that Garcinia mangostana peel extract more efficiently used in rain water corrosive media.
KAJIAN PEMANFAATAN BIJI KOPI (ARABIKA) SEBAGAI BAHAN BAKU PEMBUATAN BIODIESEL
Authors: Bella Simbolon  , Kartini Pakpahan  , Siswarni MZ
Published: October 2019

This research aims to exploit the coffee seed oil as raw material for biodiesel by esterification process, then followed by transesterification process and studied the influence of variations in the weight ratio of solvent: ground coffee beans in the coffee bean oil extraction process. The methodologies of this researchare conducted on the process of preparation of raw materials, extraction, and testing phase.  Extraction is done with a variety of types of solvent n-hexane (C6H14) and toluene (C7H8 (C6H5CH3)) and a variety of solvents through a ratio of 1:5, 1:6, 1:7 and 1:8 against the mass of each run, which is 40 gram. Another variable is still 2 hours extraction time and temperature solvent extraction with n-hexane (C6H14) (boiling point 690C) is 70-75 0c and the solvent toluene (C7H8 (C6H5CH3))(boiling point 1100C) is 110-1150C. Testing phase is done bythe use of coffee oil esterification process in the molar ratio of methanol: free fatty acid catalyst H2SO4 = 3:1 with 1% v / v for 1hour with stirring 600 rpm and transesterification process at a molar ratio of methanol: oil = 9:1 coffee with 1.75% NaOH catalyst for 2 hours with stirring 600 rpm. Esterification process as conducted preliminary due to high levels of free fatty acids coffeeoils, which is 22.2%. Extraction results include the maximum yield of the coffee oils  17.73% in toluene weight ratio: coffee powder= 6:1, and coffee oil data in the form of the density 93.75 g / ml, viscosity 59.326 cP and fatty acid composition of the highest linoleic acid 40.8765% and palmitic acid 37.4492%. The results of esterification and transesterification obtained by the methyl ester equal to 39.63% with density 0.915 g / ml, 22.5498 cSt kinematic viscosity and flash point 130 0C.
PENGARUH WAKTU FERMENTASI TERHADAP PERSENTASE PENYISIHAN CHEMICAL OXYGEN DEMAND (COD) CAMPURAN LIMBAH CAIR INDUSTRI TAPIOKA DAN AIR
Authors: Umayi Belladiana  , Wan Rizki Ansari  , Setiaty Pandia
Published: October 2019

Study about the effect of fermentation time on the percentage removal of chemical oxygen demand (COD) a mixture of tapioca liquid industrial waste and water that aims to determine the effect of water quality and quantity of bio-gas generated from tapioca industrial wastewater combined with water. The research was conducted by combining tapioca industrial wastewater with water on several compositions, namely 100: 0; 85:15; 65:35; 50:50; 35:65; 15:85 (v / v) with cow dung starter in the batch anaerobic digester systems for 24 days with a neutral pH. The optimum percentage of allowance for COD at the ratio of tapioca  liquid industrial waste and water at  15:85 with a value of 42.14% where the value of COD on day 0 was 1723 mg / L after day 24 was 997 mg / L .
EKSTRAKSI PIGMEN ANTOSIANIN DARI KULIT RAMBUTAN (NEPHELIUM LAPPACEUM) DENGAN PELARUT ETANOL
Authors: Laura Olivia Siahaan  , Elvi Rasida Florentina Hutapea  , Rondang Tambun
Published: October 2019

Rambutan fruit (Nephelium lappaceum Linn) is a kind of tropical fruits which come from Malaysia and Indonesia. Their red coloured rinds have not used yet effectively and that coloured may be due to anthocyanin that can be used for natural colours. The purpose of this research is to know the optimal condition of the extraction anthocyanin, they are particle size of rambutan rinds, temperature and extraction time. Analysis of the anthocyanin use spectrophotometer UV-Vis to detect the wavelength and the absorbance of the anthocyanin. The best conditions are rambutan rind milled by blender and extraction time for 8 hours at 70 0 of temperature. These conditions give the highest color intensity having 1,0086 of maximal absorbancy, 120,1601 mg/mL of anthocyanin concentration  and 0,6008 % of rendement.
PENGARUH PENAMBAHAN NATRIUM KLORIDA (NaCl) DAN WAKTU PERENDAMAN BUFFER FOSFAT TERHADAP PEROLEHAN CRUDE PAPAIN DARI DAUN PEPAYA (CARICA PAPAYA, L.)
Authors: Pinta Rizki Mala Hasibuan  , Mitha Alviyulita  , Farida Hanum
Published: October 2019

Papaya (Carica papaya L.) is one of the fruits of commodities internationally, either in the form of fresh fruit or as processed products. The leaves are green still not fully utilized. Papaya leaves contains papain enzyme which is a protease enzyme that very helpful for  the industry. Papain is a protease enzyme contained in papaya latex, whether in fruit, stems and leaves, as an enzyme capable of solving the protein molecules, current papain into products that are beneficial to human life, either at home or industrial ladder. This study aims to determine the effect of the degree of saturation of sodium chloride  and phosphate buffer to yield soaking rough papaya protease. This study varying the time of immersion phosphate buffer and saturation levels of sodium chloride. Analysis of protease activity was performed using UV-Vis spectrophotometer to measure the wavelength and absorbance values​​. The best research results obtained at 12 h immersion phosphate buffer with a concentration of sodium chloride 60% is 272.8222 unit / ml. In the analysis of the rendemen obtained by the best condition at the time of immersion phosphate buffer for 36 hours at a concentration of 90% is 43,5152%. In the analysis of moisture content obtained the best condition at the time of immersion of 36 hours at a concentration of 90% is 37.4266%.
PEMANFAATAN ADSORBEN DARI BIJI ASAM JAWA UNTUK MENURUNKAN BILANGAN PEROKSIDA PADA CPO (CRUDE PALM OIL)
Authors: Agus Mangiring Siburian  , Agnes Sartika Doharma Pardede  , Setiaty Pandia
Published: October 2019

This study was aimed to discover the effectiveness of tamarind seeds as adsorbent for the reduction of PV (Peroxide Value) in CPO (Crude Palm Oil) at the best adsorbent dose and contact time. Materials used were CPO, tamarind seeds, nitric acid, and distilled water. Variables observed were adsorbent : nitric acid ratio and oven temperature in adsorbent activation process, and contact time and adsorbent dose in adsorption process. This study was began with adsorbent modification, where the  cleaced and crushed tamarind seeds to pass through 140 mesh were activated with 4 N nitric acid at 1:1, 1:2, 1:3 and 1:4 of adsorbent : nitric acid ratio while heated at 80 oC for 2 hours. Adsorbent was then dried in oven at 110 oC, 120 oC, 130 oC and 140 oC. Adsorbent with the higher iodine number was used in adsorption process that was carried out by heating 100 grams of CPO on hot plate at 90 oC with 1000 rpm of stirring speed, and followed by adsorbent addition of 0.5 %, 1,0 %, and 1,5 % (of CPO used) and 25, 35, and 45 minutes of contact time, and after that oil was filtered using vacuum pump. The study results showed that the best ratio of adsorbent : nitric acid 4 N was 1:2 at 130 oC of oven temperature with 511.773 mg/g of iodine number. The best adsorbent dose was 1.0 % at 35 minutes of contact time that gave higher reduction of PV with peroxide value of 0,00868 meq/kg with the reduction percentage was 39,72 %. This study showed that nitcic acid-activated adsorbent from tamarind seeds was effective to reduce PV in CPO.
PENGARUH VARIASI VARIABEL REAKSI PADA PROSES EKSTRAKSI REAKTIF MESOKARP SAWIT UNTUK MENGHASILKAN BIODIESEL
Authors: Pascalis Novalina  , Arya Josua S  , Taslim  , Tjahjono Herawan
Published: October 2019

The conventional method for the production of biodiesel needed the oil that is extracted from the biomass before it can be transesterified into fatty acid methyl esters (FAME). Reactive extraction can be used to produce biodiesel with high-yield, low production costs, reduce the reaction time and the use of reagents and co-solvents, making it easier to produce biodiesel. In this study, reactive extraction applied to produce biodiesel from palm fruit mesocarp extracted using dimethyl carbonate as a solvent and reagents, and novozym®435 as a catalyst. Methanol was replaced by dialkyl carbonates, particularly dimethyl carbonate. Dimethyl carbonate can be used as a solvent and as a reagent, so reactive extraction is very easy to apply. The parameters will be study are reaction temperature (50, 60, and 70 °C), reaction time (8, 16, 24 hours), the molar ratio of reactants (50: 1, 60: 1, 70: 1 n/n ), the concentration of novozym® 435 (5%, 10%, 15% wt).The results showed that the highest biodiesel yield can be achivied at conditions temperature of 60 °C, reaction time 24 hours, molar ratio of reactants palm mesocarp to DMC 1:60, and novozym®435 concentration of 10wt%. The results showed that the synthesis of biodiesel via reactive extraction using palm mesocarp as raw material requires a low production cost.
HIDROLISIS HASIL DELIGNIFIKASI TANDAN KOSONG KELAPA SAWIT DALAM SISTEM CAIRAN IONIK CHOLINE CHLORIDE
Authors: Gendish Yoricya  , Shinta Aisyah Putri Dalimunthe  , Renita Manurung  , Nimpan Bangun
Published: October 2019

Palm Empty Fruit Bunches (TKKS) was the waste which has a fairly high content of lignocelluloses. Meanwhile, TKKS has not been utilize optimally. With a cellulose content of 45%-50%, TKKS then potentially be used as raw material for bioethanol. In the process of production bioethanol, delignification of lignocellulose the first phase was conducted to dissolve ligament between cellulose, hemicellulose and lignin. In this research, delignification process was carried out using NaOH in the ionic liquid system and without ionic liquids. The purpose of this research was to find out the highest content of cellulose which contained in the TKKS and to determine the hydrolysis of delignification results on palm empty fruit bunches and the best hydrolysis conditions was obtained at the hydrolysis process in the choline chloride ionic liquid system. Delignification process were performed using ionic liquids choline chloride (ChCl) in variety of cooking time with amount different ChCl. This research used TKKS powder cooked at a temperature 130 °C with a variety of cooking time 30, 60, and 90 minutes and the variation of ChCl 10%, 15% and 20% weight of TKKS. Delignification research results used ChCl obtained highest content of cellulose was 40,33%, hemicellulose 20,28%, and lignin 3,62% in cooking treatment 90 minutes and 15% ChCl. While delignification without ChCl obtained highest content of cellulose is 24,98%, hemicellulose 8,25%, and lignin 18,99% in cooking treatment 90 minutes. Delignification process using ChCl be able increase the degree of delignification as big as 61,45%. In the hydrolisis process, the main raw material used cellulose of delignification TKKS result, choline chloride, sulfatl acid, and distilled water. The hydrolysis stage in this research was carried out at temperature 105 0C, catalyst (H2SO4) 10% (w / w) cellulose, ChCl 10%, 15%, and 20% (w / w) cellulose and it was stirred at constant speed 120 rpm with reaction time of 30, 60 and 90 minutes. The result in the hydrolysis stage using ionic liquid obtained glucose. LUFF method analysis showed the maximum result of glucose 37.96% with the best conditions in reaction time 90 minutes and the amount of choline chloride 20%.
EKSTRAKSI MINYAK DARI BIJI KURMA (Phoenix dactylifera L.) DENGAN METODE SOXHLET EXTRACTION DENGAN MENGGUNAKAN ETIL ASETAT
Authors: Taslim  , Muhammad Rizky Agung  , Sigit Purwanto
Published: October 2019

Date palm seed is one of the waste by-products generated from industrial commodities. Date seed oil can be obtained through solvent extraction using a Soxhlet apparatus. In this experiment, date palm seed was used as raw material with ethyl acetate as the solvent. The experiment was carried out by varying extraction time and the mass ratio of date palm seed to solvent. The highest oil concentration of 9.5% was obtained at date palm seed to solvent mass ratio of 1:6 with extraction time of 2 hours. Peroxide value, iodine value, specific gravity, and free fatty acid content of date seed oil were, consecutively, 0.81 meq/kg oil, 10.15 mg/g, 0.80, and 0.52%. The highest fatty acid composition of date seed oil was oleic acid at 37.22% followed by lauric acid at 19.36%.
PEMANFAATAN EKSTRAK DAUN SAMBUNG NYAWA (Gynura Procumbens [Lour].Merr) SEBAGAI ANTIOKSIDAN PADA MINYAK KELAPA MENGGUNAKAN PELARUT METANOL
Authors: Mersi Suriani Sinaga  , Putri Defriska Siagian  , Rika Ariska
Published: October 2019

Sambung Nyawa leaves (Gynura Procumbens [Lour].Merr) have been used as a traditional medicine. Sambung Nyawa leaves contain flavonoid compounds, its functional as a natural antioxidant. The aim of this study was to analyze the effect of Sambung Nyawa leaves extract addition as an antioxidant and ability to preserve the quality of coconut oil. Firstly, flavonoids were extracted from Sambung Nyawa leaves with combination of raw material to solvent ratio (w/v) and extraction temperature. The extracts which gave the highest total flavonoids contents were mixed into the coconut oil  for 3 days, 6 days, 9 days, 12 days, and 15 days. Total  flavonoids contents of  Sambung Nyawa leaves extracts were analyzed by UV-Vis spectrophotometry. The analyses for coconut oil were the value of acid, iod, and peroxide number. The results showed that the highest total flavonoids contents of  1,32 %  be obtained with raw material to solvent ratio of 1:10 (w/v) and extraction temperature of 55 oC. The lowest acid number of 0.45%, the highest iod number of 7.90 gr I2/100 gr, and the lowest peroxide number of 4.40 mg O2/100 gr be obtained with stored time of 3 days for coconut oil which mixed with the Sambung Nyawa leaves extracts.
METODE OPTIMASI PADA SISTEM PENGENDALIAN PROSES TANGKI PEMANAS BERPENGADUK
Authors: Rudy Agustriyanto
Published: October 2019

In this research, PID (Proportional Integral Derivative) controller tuning was done using optimization method and the result was compared to the other well-known tuning methods (Direct synthesis, Ziegler– Nichols). The purpose of this research is to obtain the best output response when the set point and disturbance are changed. Tuning is a useful process to set the controller parameter that can affect the output response from the changing set point (servo problem) as well as from the disturbance (regulatory problem). The controller performance can be evaluated from the value of Sum Squares of Error when the system is controlled by PID controllers that is tuned with chosen method. The research result showed that optimization method was better than the other methods because it could give the best result.
PEMBUATAN SABUN DENGAN MENGGUNAKAN KULIT BUAH KAPUK (Ceiba petandra) SEBAGAI SUMBER ALKALI
Authors: Lilis Sukeksi  , Andy Junianto Sidabutar  , Chandra Sitorus
Published: October 2019

The purpose of this study is to examine the effect of reaction time and temperature toward the formed of soap product. This study begins by drying the skin of cotton and burning to gain the ash of cotton fruit skin. The combustion is done by using muffle furnace at 500 oC for 3 hours. Then, extraction is done on ash by using aquadest with a ration 1:3 to obtain alkali. This alkali will be used with cooking oil from palm in saponification process with fixed volume variable oil of 30 ml, velocity of stirring is 250 rpm, and oil volume : alkali volume  1:2 (ml). Whereas for the free variable  are reaction temperature at  60­ oC, 70 oC, 80 oC, stirring time at 60 minutes, 90 minutes, 120 minutes. The observed responses are density, acidity (pH), saponification number and free alkali. The best results were obtained at 80 °C and stirring time of 120 minutes with a density of 1.34 gr / ml, pH 9.1, saponification number of 200.349 and a 0.07% free alkali content.
PEMBUATAN KARBOKSIMETIL SELULOSA DARI KULIT PISANG KEPOK DENGAN VARIASI KONSENTRASI NATRIUM HIDROKSIDA, NATRIUM MONOKLOROASETAT, TEMPERATUR DAN WAKTU REAKSI
Authors: Saputri Ayuningtiyas  , Feni Dwi Desiyana  , Siswarni MZ
Published: October 2019

Carboxymethyl cellulose (CMC) is a derivative cellulose which is soluble an in water (hydrophilic colloid). This material effective to bind water to provide a uniform texture and increase viscosity. The aim  of this study is to utilize banana peel as a raw material to synthesis CMC and determine the best conditions in the process of synthesis CMC from banana peel. The materials used were banana peel, water, aquades, NaOH, Natirum monochloroacetat and glacial acetic acid. The variables in this study were NaOH concentration, natirum monochloroacetat mass, temperature and reaction time. In this  research consists of four stages there are preparation of raw materials, alkalization, carboxymethylation, and neutralization. The results of this research  shows the variatioon NaOH concentration 20%  and  temperature of 45oC degree, mol rasio of  cellulose:sodium monochloroacetat 1:1,6 with a reaction time of 120 minutes obtained the highest substitution degree of 0,73-0.812. The FTIR analysis shows the presence of the O-H, C-H, C = O, C-0, CH2 and 1,4 β-glycoside function groups known to have the same function groups as the commercial carboxymethyl cellulose.
KARAKTERISTIK KARBON AKTIF DARI PEMANFAATAN LIMBAH TANAMAN KELAPA SAWIT DENGAN PENAMBAHAN AKTIVATOR NATRIUM KARBONAT (Na2CO3) DAN NATRIUM KLORIDA (NaCl)
Authors: Gewa Handika  , Seri Maulina  , Vidyanova Anggun Mentari
Published: October 2019

Oil palm tree can produce 22 oil palm frond / year, the average weight of frond per rod reaches 2.2 kg, so that each hectare can produce fresh frond about 9 tons / year or equivalent to 1.64 tons / year of dry matter. Activated carbon can be used as a good absorbent agent for gas purification process and removal of organic pollutants from water, such as in liquid waste. The objective of this paper is to know the different characteristics of activated carbon from oil palm frond (elaeis guineensis jacq) as raw material with variation of activator sodium carbonate (Na2CO3) and sodium chloride (NaCl). The activator concentration used is 10% each with an activation temperature of 600 ° C. The quality of activated carbons was analyzed by surface active carbon morphology and FTIR spectra analysis on activated carbon. The result of identification with FTIR spectrophotometer showed that the activated carbon in this study contained the functional groups of O-H, C = O, C = C, C-C, and C-H.
KENDALI SISTEM BIOREAKTOR KONTINYU
Authors: Rudy Agustriyanto
Published: October 2019

Tujuan dalam industri bioproses umumnya adalah memaksimalkan pertumbuhan  mikroba dan / atau produksi beberapa senyawa yang dihasilkan oleh mikroorganisme. Untuk mencapai hal ini dengan cara yang efisien, maka diperlukan untuk menjaga lingkungan yang sesuai untuk mikroorganisme setiap saat. Tujuan utama penelitian ini adalah untuk menerapkan algoritma kendali PI (Proporsional integral) dan PID (Proporsional Integral Derivative) untuk suatu sistem bioproses. Kriteria Bode kemudian diterapkan untuk memeriksa kestabilan sistem diikuti dengan penentuan parameter pengendali menggunakan metode TLC (Tyreus-Luyben). Hasil simulasi lintas tertutup menunjukkan kinerja pengendalian yang dapat diterima.
PERBANDINGAN GUGUS FUNGSI DAN MORFOLOGI PERMUKAAN KARBON AKTIF DARI PELEPAH KELAPA SAWIT MENGGUNAKAN AKTIVATOR ASAM FOSFAT (H3PO4) DAN ASAM NITRAT (HNO3)
Authors: Vidyanova Anggun Mentari  , Gewa Handika  , Seri Maulina
Published: October 2019

Indonesia is one of the biggest producent of palm oil in the world. According to Badan Pusat Statistik (Central Bureau of Statistics), on 2016 wide of the palm oil estate in Indonesia is 11.672.861 Ha. The waste of palm oil plantations so many and isn’t used optimal, for the example is oil palm frond. Oil palm frond is one of the wet of waste with the number of production as much as 19.143.492 ton on 2016. This research will discuss the comparison of functional group and surface morphology activated carbon of oil palm frond with use H3PO­4 and HNO3 as an activator. This research purpose to know the comparison of functional group and surface morphology activated carbon of oil palm frond with use H3PO4 and HNO3 as an activator. The method includes impregnation, carbonization, and washing process. The concentration of activator is 20% with 400 oC activation temperature. This research is used morphology surface activated carbon analysis with SEM and FTIR spectrophotometer. The result of analysis with SEM show there is pore formed on activated carbon and the indentification with spechtrophotometer FTIR shows that activated carbon is contain of functional group are C=O, C=C, C-C, N=O, C-N, C-OH, CH2and C-H.
EKSTRAKSI MINYAK ATSIRI BUNGA MELATI DENGAN MENGGUNAKAN PELARUT ISOPROPIL ETER : PENGARUH WAKTU, TEMPERATUR, DAN RASIO MASSA BUNGA MELATI DENGAN VOLUME PELARUT
Authors: Febrina Iskandar  , Michael Dillo Rizki Ginting  , Iriany  , Okta Bani
Published: October 2019

Jasmine flower is one of the high value commodities. One of the applications of  jasmine flower  is jasmine essential oil. Jasmine essential oil is often used to produce high quality parfume. Extraction is one of the methods for extracting jasmine essential oil, usually by the help of solvent. In this study, the effect of extraction time, extraction temperature, and solvent to jasmine flower ratio on jasmine oil extraction was studied. The extraction was carried out at 30oC, 35oC, and 40oC for 2 hours, 3 hours, 4 hours, and 5 hours by using isopropyl ether. The ratio of jasmine flower to isopropyl ether were 1:3; 1:4; and 1:5 (m/v). The resulting jasmine oil was analyzed by GC-MS and its quality was assessed according to SNI 06-2385-2006 which include colour test, refractive index analysis, acid number analysis, and ester number analysis. This experiment showed that increasing of extraction time, extraction temperature, and volume of solvent lead to increase of absolute yield of jasmine essential oil. The highest jasmine oil yield was obtained at 10.63 %. The jasmine oil contained 45.34% benzyl acetate and had yellow color. Its refractive index, acid number, and ester number were 1.485, 26.228 mg KOH/gram jasmine essential oil, and 159.885 mg KOH/gram jasmine essential oil.
PEMBUATAN PEKTIN DARI LIMBAH KULIT JERUK (Citrus sinensis) DENGAN METODE EKSTRAKSI GELOMBANG ULTRASONIK MENGGUNAKAN PELARUT ASAM SULFAT (H2SO4)
Authors: Ayu Arimpi  , Setiaty Pandia
Published: October 2019

Pectin can be utilized in various industries of making jelly, jam, gelling, thickener, stabilizer and emulsifier. In this study the extraction of pectin from orange peel (Citrus sinensis) using ultrasonic waves and sulfuric acid (H2SO4) was conducted to determine the effect of variation in settling time and concentration of the alcohol as the pectin filtrate precipitating material on the characteristics of the pectin produced. The study was carried out with 30 minutes extraction time, extraction temperature of 70 oC using H2SO4. Variations carried out were settling time for 14 hours, 16 hours, 18 hours and 20 hours, and concentration of the alcohol ; 65%, 75%, 85% and 95%. Characteristics of pectin produced with successive characteristics: yield ranged from 16.44%-22.44%; moisture content from 4.0-9.45%; ash content of 2.34%-5.54%; equivalent weight of 510.20-865.07 mg; methoxyl content of 7.35%-10.79%; and galacturonic content of 63.71%-95.74%. The 18-hour settling time with 95% ethanol produced the most yield with the best pectin characteristics that met IPPA (International Pectin Producers Association) standards.
Pengaruh Waktu Kontak dan Massa Adsorben Biji Asam Jawa (Tamarindus indica) dengan Aktivator H3PO4 terhadap Kapasitas Adsorpsi Zat Warna Methylene Blue
Authors: Rizki Andri , Syahputra Ervan , Pandia Setiaty , Halimatuddahliana
Published: October 2019

This study aims to determine the best adsorption capacity of methylene blue with variations in the mass of the adsorbent, contact time and determine the reaction kinetics and adsorption isotherms of activated carbon. The raw material for activated carbon is tamarind seeds. Tamarind seeds is started to neutral pH and dried in an oven at 130°C to a constant weight, then mashed using a blender and sifted using a 140 mesh sieve. adsorbent 140 mesh was added to 100 ml of methylene blue solution at a stirring speed 150 rpm for each variation of contact time 30 minutes, 60 minutes, 120 minutes and 180 minutes and mass of adsorbent 0,3 gs, 0,4 gs, 0,6 gs and 0,9 gs. The efficiency of the best description of methylene blue is 98,827% with 120 minutes and pH 6 at 0,9 gs of activated carbon. The maximum methylene orange adsorption capacity is 24,670 mg/g at 100 mg/L methylene blue concentration. The model suitable for this study is the second order kinetics and Freundlich adsorption isotherm. The results of the Fourier Transform Infra-Red (FTIR) spectrophotometer on the raw material of Tamarind seeds before activated were obtained by wave number which shows the presence of functional goups C-O, O-H, and C=O goups which form a special goup found on biosorbent, functional goups that appear after activation is a C=C goup which shows an increase in carbon and C-H goups (Alkenes). The results of the Scanning Electron Microscope (SEM) characterization show that the surface morphology of the activated carbon from tamarind seeds has a surface that is open, coarse, and uniform porosity. The pores of biosorbent after activation in vacant soil without impurity.
Kajian Model Interaksi pada Adsorpsi Logam Berat Kadmium (Cd2+) dengan Menggunakan Adsorben dari Pasir Hitam
Authors: Haryanto Bode , K Sinaga Warren , T Saragih Febri
Published: October 2019

This study aimed to analyze the adsorption ability of black sand in the metal ions adsorb cadmium (Cd2+) with a concentration of 70 ppm to a solution with a pH of 4,5. The black sand is used is 40 mesh. This research was conducted by batch adsorption system naturally and adsorption kinetics modeling. Kinetics of adsorption reached equilibrium at time t = 120 minutes with the percentage concentration of adsorbed Cd2+ 18,5%. In the adsorption kinetics modeling correlation coefficient is almost the same between the equations of first order and second order in the amount of 0.98 and 0.99. The result indicated that the type of interaction Cd2+ ions on the surface of black sands occur in chemistry and physics. The adsorption kinetics of diffusion modeling of internal and external diffusion of the correlation coefficient of 0,85 and 0,71. From this data it can be seen that in this study is modeling kinetic internal diffusion trend that shows adsorbent particles are inter sand surface area that experienced internal inter-particle pore diffusion.
Pyrolysis of hardwood soda-anthraquinone spent pulping liquor
Authors: ST. PIERRE JAMIE , BEIS SEDAT , VAN HEININGEN ADRIAAN
Published: October 2019

A lignin-rich feedstock, soda-anthraquinone spent pulping liquor, was pyrolyzed in a kiln reactor. The liquor was prepared from mixed northern hardwood chips at a liquor-to-wood ratio of 3.5 L/kg, 16% effective alkali, and an H-factor of 1000 h. The spent liquor was pyrolyzed at 500°C as is, after oxygen oxidation, and with addition of sodium formate to determine the effect on bio-oil yield and product distribution. Contrary to bio-oil from sawdust, a clear phase separation of the liquid product into an aqueous layer and a denser organic layer is obtained. The predominant products found in the organic layer collected after pyrolysis are phenols with varying degrees of methylation and ethylation. The organic yield appears to go through a maximum (32 wt% on spent liquor organics) at around 25 wt% formate added on spent liquor dry solids and subsequently decreases at greater charges. Oxidation of the spent liquor prior to pyrolysis appears to have a detrimental effect on the organic yield.
Development of laboratory wet creping method to evaluate and control pulp quality for tissue
Authors: ANUKUL PREEYANUCH , KHANTAYANUWONG SOMWANG , SOMBOON PHICHIT
Published: October 2019

The required properties of tissue paper including softness and liquid absorption are predominantly manipulated by the creping process, which cannot be simply produced in the laboratory. This causes problems in controlling the stock quality prepared using the various types of industrial pulps and consequently affects the creping operation and tissue quality. Our objectives were to develop a laboratory creping method and to apply it for the evaluation and control of the quality of pulp raw materials used in industrial tissue production. The experiment consisted of the development of a laboratory wet creping method and the study of the creping devices and the creping conditions, including basis weight of the base paper, sheet dryness, and degrees of pulp refining. The results showed that the method could produce crepes on laboratory sheets and the structures of the creped sheets could be engineered to improve their softness and liquid absorption. The tested pulps were found to produce significantly different responses to the laboratory wet creping, depending on their morphology and the mechanical treatments. The examination of industrial pulps found that eucalypt, bagasse, bamboo, and deinking pulps needed to be manipulated using different refining levels and required optimization among their softness, liquid absorption, and strength properties.
Understanding coating strength at the molecular and microscopic level
Authors: TOIVAKKA MARTTI , ALAM PARVEZ , TOUAITI FARID , ORAVILAHTI ANNIINA , ORAVILAHTI TUOMAS , KNUUTINEN JUHA , NILSSON ROBERT , PAHLEVAN MAHDI , AHOKAS MIA , WILEN CARL-ERIC
Published: October 2019

Insufficient coating strength can lead to various problems in printing and converting of pigment-coated paper and paperboard. The loss in strength, especially in the presence of printing liquids, can result from poor adhesion between the binder and the coating pigments. Experiments and numerical simulations were used to better understand the microscopic and molecular level interactions between the latex-binder and dispersant-covered coating pigments used in paper coating. Micromechanical simulations were carried out to identify the microstructural variables most influential to strength. Several new pigment dispersing agents were synthesized with the reversible addition-fragmentation chain transfer copolymerization technique, and their dispersing effect and influence on dry and wet strength of pigment coating were evaluated. Molecular level interactions between binders, coating pigments, and various functional groups used in the dispersants were studied with molecular modeling. Furthermore, dynamic mechanical thermal analysis was used to examine the influence of both commercial and novel dispersants on the pigment-latex interactions. Some of the novel dispersants synthesized and tested show promise in improving the wet strength of the coating while providing as good as or better dispersing effect when compared to a sodium polyacrylate–based commercial dispersant.
Upgrading aeration system performance in secondary basins treating pulp and paper wastewater: A review
Authors: PALUMBO J. , CYR P. , SACKELLARES R. , WIEGAND P.
Published: October 2019

Secondary wastewater treatment aeration systems are an integral part of many mills’ pollution control operations. Several factors can drive the need for aeration system performance upgrades, including changing mill production regimes, increased environmental compliance requirements, and equipment deterioration. However, optimal upgrade designs can be difficult to achieve because of the many interrelated and site-specific factors that influence secondary treatment performance. This article is intended as an introductory resource to understanding and addressing the complexities often associated with achieving an optimal aeration system upgrade. Relevant aeration and mixing science fundamentals and commonly employed aeration technologies are summarized and reviewed. The application of wastewater treatment computer models is examined as it pertains to aeration system design and operation. Recommendations for aeration system upgrade projects include specific information needs, potential resource requirements, general model selection guidance, and discussion of potential model application methodologies.
Computer modeling as tools to estimate the impact of fuel type on the capacity rating of lime kilns
Authors: GOROG J. PETER , LEARY W. RAY , WANG DAVID , DAVIS KEVIN
Published: October 2019

In response to the drop in the price of natural gas, the U.S. pulp and paper industry has switched from using fuel oil to natural gas to fire kilns used to regenerate lime in the kraft process. While being financially attractive, replacing fuel oil with natural gas can be challenging. This is particularity true when the capacity rating is constrained by the temperatures of the gas exiting the kiln. In the worst case scenario, the increase in flue gas temperatures associated with switching from fuel oil to natural gas can significantly de-rate the capacity of the kiln. This paper describes a range of computational modeling tools that can be used to estimate the impacts of kiln geometry, fuel type, operating conditions, and burner design on kiln performance. Data taken from operating kilns is
presented, which validates the use of these models. A detailed case study is presented showing how small amounts of torrefied wood can be co-fired with natural gas as a replacement for fuel oil without de-rating the capacity of the kiln. The visualization of the flow fields, temperature distributions, and species concentrations provided by computer models are critical to optimizing kiln operations as new fuels are being considered as replacements for more expensive, carbon intensive fuel oil.
Impact of cofiring biofuels and fossil fuels on lime kiln operation
Authors: MANNING RICHARD , TRAN HONGHI
Published: October 2019

Lime kilns are used to calcine lime mud to produce lime for reuse in the causticizing plant of pulp mills. With significant increase in fossil fuel costs and the sustained drive to minimize carbon footprint, there has been a great deal of research and development of the biorefinery concept and production of biofuels for use within pulp mills. Several new biofuels will become available, together with traditional mill derived fuels such as tall oil. In considering use of biofuels for replacement of fossil fuels in the lime kiln, each fuel has a different impact on kiln performance. An assessment on kiln performance can be achieved and compared to either heavy fuel oil or natural gas. In most cases, the lime kiln fuels with high oxygen content and moderately low calorific values burn in a similar manner as natural gas; hence, in assessing impact on kiln performance, production and induced draft fan limits together with kiln exit gas temperatures need to be considered.
The influence of strain rate and pulp properties on the stress-strain curve and relaxation rate of wet paper
Authors: KOUKO JARMO , RETULAINEN ELIAS
Published: October 2019

Sufficient tension of the wet web is crucial for paper machine runnability. As profitability pressures have been increasing, the potential to improve runnability is of interest. The runnability of wet paper is especially important for paper machines running at high speeds, making paper at lower grammage, and using large amounts of filler or recovered paper. The typical location of web breaks depends on the paper grade and paper machine. A break typically takes place when the paper is wet and a fast draw is applied to the web. Because information on wet paper is scarce, especially information on the effect of strain rate on the tensile properties, we investigated the effects of strain rate on the tension-strain curve and relaxation of wet paper and how they depend on pulp type, refining, solids content, and fines. Higher strain rate leads to higher tensile strength, tensile stiffness, and relaxation rate. The initial wet strength and stiffness of the studied pulps, bleached softwood kraft pulp and bleached hardwood kraft pulp, were increased by increasing the solids content, fines, wet pressing, and refining. At a constant strain rate and constant strain, the tension at a certain moment depended strongly on the initial tension and thus on the tensile stiffness.
Some observations towards improved predictive models for box compression strength
Authors: W. COFFIN DOUGLAS
Published: October 2019

A McKee-Urbanik type equation for box compression testing (BCT) strength prediction was evaluated using the box data of McKee, Gander, and Wachuta and the tube strength data of Batelka and Smith. Instead of separating BCT into separate panel loads, an effective width was deemed adequate for the data set. Although not much can be done to improve the fit of the McKee data over the McKee formula, the fit of the tube data was slightly better than previously reported in the literature. Unlike previous literature, the fitting parameters used in the model directly target the uncertainty we have in predicting a critical buckling load for a panel (K = edge restraint, κ = twisting resistance, α = relative scaling). The lack of ability to improve the McKee data set is attributed to the variety of boxes tested and the dependence of BCT on unmeasured properties. The century-old take-home message reiterated in this paper is that focused research is needed to replace estimated or fitted parameters with independently measured quantities, which should result in a decrease in the number of boxes with unsatisfactory predictions of BCT.
Surface energy of cellulosic materials: The effect of particle morphology, particle size, and hydroxyl number
Authors: PENG YUCHENG , J. GARDNER DOUGLAS
Published: October 2019

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.
Eucalyptus fiber modification using dielectric-barrier discharge
Authors: JARDIM C.M. , OLIVEIRA R.C. , HSIEH J.S. , RAGAUSKAS A.J. , ELDER T.
Published: October 2019

This study involves an investigation of the impact of the various levels of atmospheric dielectricbarrier discharge (DBD) treatment on the surface of eucalyptus fibers at different levels of beating with the objective of enhancing paper strength properties. The DBD treatment led to significant improvements in wet-strength tensile properties, increasing them by 2%-112%, as a function of the dosage of atmospheric plasma applied. Also, using controlled dosages of the DBD treatment, dry-strength tensile could be improved, reaching a 58% increase. In addition, non-beaten samples showed greater increases in strength properties than the beaten samples. Moreover, the acid surface content was unaltered by the DBD treatment, perhaps due to over-oxidation and generation of low molecular weight species that are easily removed by washing with water. Furthermore, increases in wettability could be observed for specific DBD dosage of treatments. Atomic force microscopy images of the treated handsheets showed that DBD treatment results in surface smoothing of the fibers. In conclusion, DBD treatment was shown tobe an effective approach for eucalyptus fiber modification, especially in terms of enhancement of wet-strength properties.
Rheology of pulp suspensions of bleached sugarcane bagasse: Effect of consistency and temperature
Authors: SÁNCHEZ JORGE H. , C. QUINTANA GERMÁN , E. FAJARDO MERY
Published: October 2019

Rheological properties, such as yield stress and apparent viscosity, of pulp suspensions of bleached sugarcane bagasse were studied in a stress-shear rate controlled rheometer using concentric cylinders geometry. Results were statistically analyzed and presented as a function of the suspension consistency (0.5% ≤ Cm ≤ 4.0%) and temperature (20°C, 40°C, and 60°C). The yield stress was influenced by the consistency and temperature. The apparent viscosity was influenced only by the consistency. A power law model was fitted to the experimental results of yield stress. In flow tests, all the suspensions showed shear-thinning behavior, which was in agreement with the Carreau-Yasuda model.
Перспективи розвитку спроможностей Сухопутних військ Збройних Сил України
Authors: Попко С. М. , Музиченко Д. П.
Published: October 2019

У статті наведені перспективи розвитку спроможностей Сухопутних військ Збройних Сил України з урахуванням воєнних загроз національній безпеці України, корегування функцій видів Збройних Сил України й тенденцій розвитку збройної боротьби.
Гібридна війна Росії проти України: історичний вимір
Authors: Сегеда С. П. , Шевчук В. П.
Published: October 2019

У статті аналізується гібридна війна Російської Федерації проти України з урахуванням сучасного наукового дискурсу. З’ясовуються причини російсько-українського протистояння. Виокремлюються елементи російської гібридної війни, які застосовуються проти України. Доводиться, що Московія/Росія на різних історичних етапах використовувала гібридні технології проти України, щоб захопити (окупувати) її територію.
Should social accountability be considered as one of the key benchmarks for excellence in medical education?
Authors: Majumder Md Anwarul Azim
Published: October 2019

Abstract not available

South East Asia Journal of Public Health Vol.8(1) 2018: 1-2
Traumatic Experience of World War I in Diaries of Volodymyr Vynnychenko: Impressions from Katerynoslav
Authors: Narivska Valentyna
Published: October 2019

The paper analyzes the diaries by the famous Ukrainian writer, artist and political leader Volodymyr Vynnychenko (1880–1951) that highlight events of the World War I. The idea to start the diary just at that time was interpreted by the author himself as an event of his artistic life, ‘a philosophy of action’. It determined the presence of such notions as ‘attention’, ‘a stop above the life’, ‘moments of life’, ‘a beam of light’ used as philosophic prolegomena in the notes about war and traumatic experience of its ﬁrst days, which the writer faced in Katerynoslav (now Dnipro). The depth of traumatism is evident against the background of the idyllic records from the Dniper steamship, combined with romantic and patriarchal Gogol-like allusions. The writer noted the transition to the Katerynoslav events carefully and clearly. As a politician he was interested in the conditions of workers, labor unrest, Black-Hundred outrage and the city’s perception of the beginning of the war as a trauma. The author of the diary didn’t separate himself from this tragic ﬂow of events. He experienced these events directly and deeply, making correspondent records. It was the image of the station full of people leaving for the battleﬁ eld that demonstrated the trauma penetrating into the depth of the human consciousness, deforming the general state and behavior. The experience of the diarist led him to conclusion that not only Sarajevo, but also Katerynoslav was the point of the war. The epicenter of the events is in the notes on the station scenes that clearly divided the world into the lost peace and war, causing dramatic changes in human consciousness and behavior. This awareness was facilitated by the successful use of techniques belonging to naturalism, realism, impressionism, and expressionism.