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Growth responses of five non toxic alexandrium species (Dinophyceae) to temperature and salinity
"Growth response of five clonal cultues of alexandrium obtained from tropical and temperate waters were examined experiments were carried out in eighteen variable temperature-salinity conditions (temperatures of 15 oC,-20oC and 25oC;salinities between 5 to 30 psu) under constant illumination of 150 kurang lebih10.0 umol m2s1 at 15:9 light:dark photo-cycle...."
Artikel Jurnal  Universitas Indonesia Library
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Ratu Mahdiyah Nabilah
Efek Kenaikan Suhu Hidrotermal terhadap pH Larutan Na3PO4 pada Pembuatan Blok Hidroksiapatit dari Blok Gipsum = Effect of Temperature Increase to pH Na3PO4 Solution in Fabrication of Hydroxyapatite Block from Gypsum Block
"Latar belakang: Hidroksiapatit merupakan salah satu bahan alloplast yang banyak digunakan di bidang kedokteran gigi. Komposisi hidroksiapatit sama dengan komposisi anorganik tulang dan gigi manusia sehingga bersifat biokompatibel dan bioaktif. Selain itu, hidroksiapatit juga bersifat osteokonduktif. Salah satu metode pembuatan hidroksiapatit yaitu metode disolusi-presipitasi dalam kondisi hidrotermal. Pembuatan blok hidroksiapatit dengan metode disolusi-presipitasi pada suhu 100°C selama 48 jam masih menghasilkan fasa lain selain hidroksiapatit, yaitu dicalcium phosphate anhydrous (DCPA). Fasa DCPA dan/atau fasa DCPD (dicalcium phosphate dehydrate) dapat terbentuk dalam pH asam. Sedangkan, hidroksiapatit dapat terbentuk pada pH basa. Oleh karena itu, pH dapat dijadikan indikator secara tidak langsung mengenai hasil fasa yang terbentuk. Gipsum dipilih sebagai prekursor karena mengandung ion kalsium (Ca2+). Sedangkan, larutan Na3PO4 digunakan karena mengandung ion fosfat (PO43-), bersifat tidak toksik, dan memiliki pH basa.
Tujuan: Penelitian ini bertujuan untuk mengetahui pengaruh perbedaan suhu terhadap perubahan pH larutan Na3PO4 dalam pembuatan blok hidroksiapatit dari blok gipsum.
Metode Penelitian: Penelitian ini menggunakan blok gipsum dan larutan Na3PO4 sebagai prekursor untuk membuat blok hidroksiapatit. Spesimen yang digunakan berupa 30 mL larutan 1 mol/L Na3PO4 sebanyak dua beaker glass larutan. Sebelum dilakukan perendaman, pH larutan diukur terlebih dahulu untuk mengetahui pH awal larutan 1 mol/L Na3PO4. Lima belas blok gipsum direndam dalam 30 mL larutan 1 mol/L Na3PO4 dengan suhu yang berbeda yaitu 100°C, 140°C, dan 180°C pada kondisi hidrotermal selama 48 jam. Setelah perendaman, blok dan larutan 1 mol/L Na3PO4 dipisahkan. Kemudian, pH larutan 1 mol/L Na3PO4 diukur kembali menggunakan pH meter Eutech Instruments pH 700 untuk mendapatkan pH larutan 1 mol/L Na3PO4 setelah digunakan untuk perendaman selama 48 jam.
Hasil: Nilai pH larutan 1 mol/L Na3PO4 sebelum digunakan untuk perendaman yaitu 13,04. Sedangkan, nilai pH larutan 1 mol/L Na3PO4 setelah digunakan untuk perendaman pada suhu 100°C, 140°C, dan 180°C berturut-turut yaitu 12,72; 12,67; dan 12,30.
Kesimpulan: Peningkatan suhu yang digunakan menyebabkan penurunan pH larutan 1 mol/L Na3PO4. Namun, pH akhir larutan masih cukup basa untuk hidroksiapatit terbentuk. Namun, penelitian lebih lanjut masih perlu dilakukan mengenai pengukuran pH larutan Na3PO4 dengan sampel yang lebih banyak.
Background: Hydroxyapatite is one of the alloplastic materials that is widely used in dentistry. The composition of hydroxyapatite is similar with the inorganic composition of human bone so that it is biocompatible and bioactive. Besides, hydroxyapatite is also osteoconductive. One of the fabrication methods of hydroxyapatite is the dissolution-precipitation method under hydrothermal conditions. The fabrication of hydroxyapatite block with the dissolution-precipitation method at 100°C for 48 hours still produced other phase except hydroxyapatite, specifically dicalcium phosphate anhydrous (DCPA). DCPA and/or dicalcium phosphate dehydrate (DCPD) phase can be obtained if the pH is acidic. Meanwhile, hydroxyapatite can be fabricated on the alkaline pH condition. Therefore, the pH value can be the indirect indicator to predict the phase product. Gypsum was chosen as a precursor because it has calcium ions (Ca2+). Na3PO4 solution was used because it contained phosphate ions (PO43+), non-toxic, and has an alkaline pH value.
Objective: This study aimed to determine the effect of temperature differences on changes of the pH value of Na3PO4 solution in the fabrication of hydroxyapatite block from gypsum block.
Methods: This study used gypsum block and Na3PO4 solution as precursors to fabricate hydroxyapatite block. The specimens of this study were two beaker glasses of 30 mL of 1 mol/L Na3PO4 solution. Before the immersion, the pH value of the solution was measured first to determine the initial pH value of 1 mol/L Na3PO4 solution. Fifteen specimens of gypsum blocks were immersed in 30 mL of 1 mol/L Na3PO4 solution with different temperatures specifically 100°C, 140°C, and 180°C under the hydrothermal condition for 48 hours. After the immersion, the blocks and the 1 mol/L Na3PO4 solution were separated. Then, the pH value of 1 mol/L Na3PO4 solution was measured using Eutech Instruments pH 700 pH meter to obtain the pH of 1 mol/L Na3PO4 solution after being used for immersion for 48 hours.
Results: The pH value of 1 mol/L Na3PO4 solution before being used for the immersion was 13,04. Meanwhile, the pH value of 1 mol/L Na3PO4 solution after being used for the immersion at 100°C, 140°C, and 180°C respectively were 12.72, 12.67, and 12.30.
Conclusions: The increase in the temperature caused the derivation of the pH value of 1 mol/L Na3PO4 solution. Nevertheless, the final pH value was still alkaline enough for hydroxyapatite to be formed. However, further research still needs to be done to measure the pH value of the Na3PO4 solution with more samples."
Jakarta: Fakultas Kedokteran Gigi Universitas Indonesia, 2021
S-pdf
UI - Skripsi Membership  Universitas Indonesia Library
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Temperature measurement
New York: John Wiley & Sons, 2000
536.502 87 TEM
Buku Teks  Universitas Indonesia Library
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Childs, Peter R.N.
Practical temperature measurement
Oxford: Butterworth-Heinemann, 2001
536.502 87 CHI p
Buku Teks  Universitas Indonesia Library
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Andi Muhammad Natsir Amal
Temperature measurement by using Mach-Zehnder interferometer
"ABSTRACT
We proposed a method for measuring the temperature by using Mach - Zehnder Interferometer, one arms of Mach - Zehnder Interferometer was used as a test arms which was disturbed by an object, it's temperature was to be measured. In our experiment, we used a combustion flame and a heated welder with temperature variation as a testing object.
System, contains He - Ne laser source, two beams splatters and two mirrors which form two arms of interferometer, with a length of 1,06 meter.
The experiment results shows that the variation of temperature could give the difference of fringe spacing at the screen. Several photographs of fringe pattern on the screen have been successfully taken on both under temperature disturbance and normal condition.
The comparison between the fringe spacing under those two conditions could give the information about temperature of the testing objects.
This result was also compared with the measurement using thermocouple with digital display. This comparison gives us a good agreement."
1992
T-Pdf
UI - Tesis Membership  Universitas Indonesia Library
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Haslinda Mohamed Kamar
Effect of regeneration air temperature on desiccant wheel performance
"Desiccant wheels are used as an air dehumidifier in air-conditioning and industrial applications. Desiccant wheel performance determines the size and cost of the whole system. A good desiccant wheel is one that saves energy usage. This article presents an experimental investigation on the effects of varying the regeneration air temperature, viz., 50, 60 and 70oC, on desiccant wheel performance. Three performance criteria were considered, namely condition of process outlet air, dehumidifier efficiencies and dehumidification rate. Two kinds of efficiency of the desiccant wheel dehumidifier were examined, namely thermal and dehumidification efficiency. Results of the experiments show that increasing the regeneration air temperature increases the dry bulb temperature of the process outlet air. However the moisture content of the process outlet air is reduced. The dehumidification efficiency of the desiccant wheel decreases with increasing regeneration air temperature, i.e., 46.7, 45.8 and 45.3 % for 50, 60 and 70oC, respectively. In contrast, the dehumidification rate increases with an increase in the regeneration air temperature, namely 32.6, 37.1 and 40.2 g/h for 50, 60 and 70oC, respectively."
Depok: Faculty of Engineering, Universitas Indonesia, 2016
UI-IJTECH 7:2 (2016)
Artikel Jurnal  Universitas Indonesia Library
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Ken Satrio Utomo
Studi karakteristik pengaruh ambient temperature terhadap pelepasan muatan baterai lead acid = Characteristics study of ambient temperature effect on discharging lead acid battery
"Baterai merupakan alat penyimpan energi dalam bentuk muatan listrik. Baterai kini menjadi perhatian karena memiliki peran yang sangat penting bagi perkembangan teknologi energi terbarukan. Pada skripsi ini, penulis melakukan penelitian pada baterai, terutama baterai lead acid dengan cara mengatur ambient temperature dari 25°C, 30°C, 35°C, 40°C, 45°C, 50°C yang dihubungkan ke beban resistif murni berupa lampu pijar 120 watt dan 240 watt. Jenis baterai yang digunakan memiliki rating 12 V, 45 Ah dengan merk Global. Tegangan baterai akan dirubah terlebih dahulu dengan menggunakan inverter agar dapat mensuplai lampu pijar. Besarnya tegangan dan arus akan dicatat dengan menggunakan alat ukur berupa voltmeter dan amperemeter yang akan dicatat pada setiap menitnya. Selanjutnya, data yang diperoleh akan direpresentasikan dalam bentuk grafik untuk melihat perubahan yang terjadi akibat perubahan ambient temperature.
Dari hasil penelitian, ambient temperature mempengaruhi penurunan level tegangan, waktu baterai dalam mensuplai beban, dan energi yang disuplai baterai selama pembebanan berlangsung. Semakin tinggi ambient temperature, maka laju penurunan tegangannya akan semakin cepat. Pada beban 120 watt, baterai dapat mensuplai beban selama 193 menit dan energi yang dapat dikirim oleh baterai mencapai 476,3 Wh. Sedangkan pada beban 240 watt, baterai hanya mampu mensuplai beban selama 76 menit dan energi yang dapat dikirim oleh baterai mencapai 353,77 Wh.
Battery is energy storage device in the form of electric charge. Nowadays, battery has an important role for the development of renewable energy technologies. In this thesis, writer conducted research on battery, especially to lead acid battery by regulating the ambient temperature of 25°C, 30°C, 35°C, 40°C, 45°C, 50°C which is connected to purely resistive load such as incandescent bulbs of 120 watt and 240 watt. The type of battery that used has rating 12 V, 45 Ah by Global. Battery will be converted into AC voltage by using inverter in order to supply the load. The magnitude of voltage and current will be recorded by using a measuring instrument such as voltmeter and amperemeter every minute. Furthermore, the data obtained will be represented in the form of graph to see the changes that occur due to change of ambient temperature.
From the research, the ambient temperature affect the drop voltage level, battery time to supply the load, and the energy supplied during the load. The higher temperature, the rate decrease in the voltage will be faster. At 120 watt, the battery can supply the load for 193 minutes and the energy that can be delivered reaches 476,3 Wh. While the load of 240 watt, the battery is only able to supply the load for 76 minutes and the energy that can be delivered reaches 353,77 Wh."
Depok: Fakultas Teknik Universitas Indonesia, 2014
S58898
UI - Skripsi Membership  Universitas Indonesia Library
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Variation of nocturnal surface temperature within suburban residential land use: a case study on Suburban Fairfield, Western Sydney, Australia
"This article deals with nocturnal variation of surface temperature within suburban Fairfield based on field observation. The data was acquired by traversing a route consisted of 45 measurement points. The measurements were conducted at 6, 7, 9, and 9 pm respectively. The result shows that there were both spatial and temporal variations of surface temperature over the study area, particularly when the individual surface type was considered. It was observed that the variations are caused by some factors. The result also show that there was a quite good relation between the air and surface temperature. This can be a base in developing a method for observing heat islands using thermal remote sensing technique in the future. "
GEOUGM 28:72 (1996)
Artikel Jurnal  Universitas Indonesia Library
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Arif Budiman
Perkiraan pembebanan dan kondisi transformator distribusi berdasarkan temperatur ambient = Estimation of distribution transformer loading and condition base on ambient temperature measurement
"Transformator Distribusi tegangan menengah merupakan bagian yang tak terpisahkan dari sistem penyaluran tenaga listrik dari Perusahaan listrik ke pelanggan yang berfungsi sebagai penurun tegangan dari tegangan menengah ke tegangan rendah. Dalam sebuah Gardu Distribusi tegangan menengah 20 kV, transformator merupakan material / peralatan yang membutuhkan investasi cukup besar dibandingkan peralatan lain di dalam gardu tersebut sehingga transformator distribusi diharapkan dapat menyalurkan energi listrik secara terus-menerus sesuai masa guna yang ditetapkan.
Salah satu cara untuk menentukan perkiraan pembebanan dan kondisi sebuah transformator distribusi yaitu dengan mengetahui batasan temperatur yang dapat diterima oleh sebuah transformator itu sendiri yang dipengaruhi oleh beberapa faktor, dan pada thesis ini faktor yang akan dikaji adalah faktor temperatur ambient.
Penelitian ini dilakukan dengan cara pengambilan data secara langsung di beberapa gardu distrubusi PT.PLN (persero) Distribusi Jakarta Raya & tangerang dengan menggunakan alat pengukur suhu ruang, thermovision dan tang ampere sebagai pengukur temperatur dan beban pada transformator serta dengan cara perhitungan sebagai perbandingan dan dasar dalam menentukan kondisi transformator distribusi.
Penelitian ini menunjukan pengaruh temperature ambient yang cukup signifikan terhadap kenaikan temperatur oil transformator baik mengunakan alat ukur maupun dengan perhitungan, dimana saat temperatur ambient 30°C & 45°C pada beban 80% akan menghasilkan temperatur oil sebesar 66,2°C & 81,2°C.
Medium voltage Distribution transformer is an integral part of the electrical power supply system from electrical company to customers that have a fuction to lowering or deacreasing medium voltage to low voltage. In a medium voltage distribution substation 20 kV, the transformer is a material / equipment that requiring substantial investment compared to other equipment in the substation, therefore the distribution transformer is expected to distribute electrical energy continuously according to the specified period.
One way to estimate distribution transformer loading and condition is knowing the limits of acceptable temperature by a transformer it self that influenced by several factors, and in this study the factors that will be examined is ambient temperature factor.
This research was done by taking data directly in several distribution substations PT.PLN(Persero) Distribusi Jakarta Raya & Tangerang using room temperature gauges, thermovision and ampere pliers as measuring the temperature and the load on the transformer and also the calculation method as a basis of comparison and in determining the conditions of distribution transformer.
This study shows the influence of the ambient temperature significantly to the rise in temperature of the oil transformer by using the measuring instrument and the calculation, when the current ambient temperature 30 ° C and 45 ° C at 80% load will produces oil temperature 66.2 ° C and 81.2 ° C."
Depok: Fakultas Teknik Universitas Indonesia, 2015
T44663
UI - Tesis Membership  Universitas Indonesia Library
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analysis of stream water temperature changes on different forest type watersheds; cases study at field measurements in kochi region and comparing with other regions in Japan
"The changes in stream water temperture help to identify the mechanism that generates the initil response . "
2010
551 LIMNO 17:2 (2010)
Artikel Jurnal  Universitas Indonesia Library
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