Single Exponential
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2021 ◽  
Author(s):  
◽  
Nelly Malassagne-Bulgarelli

<p>Emulsions are kinetically stabilised mixtures of two immiscible fluids (e.g. oil and water). They are encountered in many industrial applications including cosmetics, food, road, drug delivery and paint technology. Despite their wide spread use, the formulation of emulsions remains largely empirical. The nature of the relationships between ingredients, composition, emulsification method and energy input, defining the microstructure (e.g. droplet size distribution and surfactant packing at the oil/water interface), the dynamics (e.g. interdroplet exchange) and the lifetime of emulsions, is still poorly understood. In particular, little work has focused on the mutual interactions between emulsifier and oil molecules and how these affect the properties of the interfacial domain and emulsion dynamics. The emulsion system oil/Triton X-100/water was investigated, where Triton X-100 is a commercially available non ionic surfactant and the oil is one of toluene, p-xylene or octane. The microstructure and the dynamics of these oil/Triton X-100/water emulsions were monitored upon varying oil type, oil concentration, emulsion age and ionic strength while maintaining the oil-to-surfactant weight ratio, temperature, energy input and emulsification method constant. For this purpose, laser scanning confocal microscopy, cryo scanning electron microscopy (cryo-SEM), pulsed field gradient NMR (PFG-NMR), macroscopic phase separation and light scattering techniques were used as experimental techniques. The occurrence of an oil exchange between oil droplets that is not coupled to droplet growth and emulsion destabilization is reported for the three oil systems: toluene, p-xylene or octane. The mixture of two separately stained emulsions, using green and red fluorescing dye molecules, leads to all droplets emitting yellow fluorescence under the confocal microscope within ∼10 min of mixing due to the interdroplet exchange of the two water insoluble dyes. Furthermore, the PFG-NMR data for both toluene and p-xylene systems indicate that, for long observation times, Δ, the echo attenuation of the oil signal decays as a single exponential upon increasing the diffusion parameters. In other words the individual motions of the droplets and oil molecules are described by a unique diffusion coefficient belying the system polydispersity and indicative of a dynamic process occurring on a time scale faster than the observation time. One way to explain this outcome is to consider a motional averaging of the oil diffusion arising from either oil permeation upon droplet collision or reversible coalescence of the droplets. These two mechanisms are supported by the extensive droplet contact observed by cryo-SEM. Such an oil transfer occurring in three distinct oil systems, independently of emulsion destabilization, has not been reported previously. Upon decreasing the NMR observation time below a specific value, Δswitch, a switch of the echo attenuation data was detected between a single exponential and a multiexponential decay, the latter indicative of the emulsion droplet size distribution. The time scale of the oil transfer, Δswitch, was probed upon varying oil type, oil concentration, emulsion age and ionic strength. In particular, the time scale of the oil exchange is an increasing function, spanning from ~300 ms to ~3 s, of droplet concentration in toluene emulsions despite the concomitant increase of the droplet collision frequency. Upon increasing the toluene content and decreasing the mean interdroplet spacing, the oil droplets are kinetically stabilized by the enhancement of the surfactant packing at the oil/water interface. In addition to the surfactant packing at the surface of the oil droplets, ionic strength and droplet size, the rate of oil exchange is controlled by the mutual interactions between oil and Triton X-100 molecules. The rate of oil transfer is a decreasing function from toluene to p-xylene to octane. The increase of the mean droplet size in the same order cannot solely account for the observed slowdown of the oil exchange. The macroscopic phase separation data indicate that the Triton X-100 layer is increasingly robust with respect to oil transfer from toluene to p-xylene to octane. This can be compared with the oil exchange process and explained in terms of oil penetration effects into the surfactant layer and energy cost for hole nucleation.</p>


2021 ◽  
Author(s):  
◽  
Nelly Malassagne-Bulgarelli

<p>Emulsions are kinetically stabilised mixtures of two immiscible fluids (e.g. oil and water). They are encountered in many industrial applications including cosmetics, food, road, drug delivery and paint technology. Despite their wide spread use, the formulation of emulsions remains largely empirical. The nature of the relationships between ingredients, composition, emulsification method and energy input, defining the microstructure (e.g. droplet size distribution and surfactant packing at the oil/water interface), the dynamics (e.g. interdroplet exchange) and the lifetime of emulsions, is still poorly understood. In particular, little work has focused on the mutual interactions between emulsifier and oil molecules and how these affect the properties of the interfacial domain and emulsion dynamics. The emulsion system oil/Triton X-100/water was investigated, where Triton X-100 is a commercially available non ionic surfactant and the oil is one of toluene, p-xylene or octane. The microstructure and the dynamics of these oil/Triton X-100/water emulsions were monitored upon varying oil type, oil concentration, emulsion age and ionic strength while maintaining the oil-to-surfactant weight ratio, temperature, energy input and emulsification method constant. For this purpose, laser scanning confocal microscopy, cryo scanning electron microscopy (cryo-SEM), pulsed field gradient NMR (PFG-NMR), macroscopic phase separation and light scattering techniques were used as experimental techniques. The occurrence of an oil exchange between oil droplets that is not coupled to droplet growth and emulsion destabilization is reported for the three oil systems: toluene, p-xylene or octane. The mixture of two separately stained emulsions, using green and red fluorescing dye molecules, leads to all droplets emitting yellow fluorescence under the confocal microscope within ∼10 min of mixing due to the interdroplet exchange of the two water insoluble dyes. Furthermore, the PFG-NMR data for both toluene and p-xylene systems indicate that, for long observation times, Δ, the echo attenuation of the oil signal decays as a single exponential upon increasing the diffusion parameters. In other words the individual motions of the droplets and oil molecules are described by a unique diffusion coefficient belying the system polydispersity and indicative of a dynamic process occurring on a time scale faster than the observation time. One way to explain this outcome is to consider a motional averaging of the oil diffusion arising from either oil permeation upon droplet collision or reversible coalescence of the droplets. These two mechanisms are supported by the extensive droplet contact observed by cryo-SEM. Such an oil transfer occurring in three distinct oil systems, independently of emulsion destabilization, has not been reported previously. Upon decreasing the NMR observation time below a specific value, Δswitch, a switch of the echo attenuation data was detected between a single exponential and a multiexponential decay, the latter indicative of the emulsion droplet size distribution. The time scale of the oil transfer, Δswitch, was probed upon varying oil type, oil concentration, emulsion age and ionic strength. In particular, the time scale of the oil exchange is an increasing function, spanning from ~300 ms to ~3 s, of droplet concentration in toluene emulsions despite the concomitant increase of the droplet collision frequency. Upon increasing the toluene content and decreasing the mean interdroplet spacing, the oil droplets are kinetically stabilized by the enhancement of the surfactant packing at the oil/water interface. In addition to the surfactant packing at the surface of the oil droplets, ionic strength and droplet size, the rate of oil exchange is controlled by the mutual interactions between oil and Triton X-100 molecules. The rate of oil transfer is a decreasing function from toluene to p-xylene to octane. The increase of the mean droplet size in the same order cannot solely account for the observed slowdown of the oil exchange. The macroscopic phase separation data indicate that the Triton X-100 layer is increasingly robust with respect to oil transfer from toluene to p-xylene to octane. This can be compared with the oil exchange process and explained in terms of oil penetration effects into the surfactant layer and energy cost for hole nucleation.</p>


2021 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Heri Setyawan ◽  
Sri Hariyati Fitriasih ◽  
Retno Tri Vulandari

The prediction of the quantity of product sales in the future is intended to control the amount of existing product stock, so that product shortages or excess stock can be minimized. When the quantity of sales can be predicted accurately, the fulfillment of consumer demand can be sought on time and the cooperation of the store with the relationship is maintained well so that the store can avoid losing both sales and consumers. The purpose of this study is to compare the effectiveness of the use of the Single Exponential Smoothing method and methods Double Exponential Smoothing with a smoothing parameter value a = 0.5 for forecasting sales by comparing the error values in the two methods using the Mean Squared Error (MSE) method, the MSE results of the Single Exponential Smoothing method is 4967.75 while the MSE Double Exponential Smoothing is 5113.03. Thus, the Single Exponential Smoothing method is more accurate than Double Exponential Smoothing in calculating book sales forecasting because it has a low MSE value.


2021 ◽  
Vol 11 (2) ◽  
pp. 543-550
Author(s):  
Ni Putu Surya Widitriani ◽  
Ida Bagus Ary Indra Iswara ◽  
Wayan Gede Suka Parwita

Peramalan merupakan seni dan ilmu dalam memprediksi sesuatu di masa yang akan datang. Proses peramalan akan melibatkan data historis pada masa lampau (seperti data penjualan tahun lalu) dan memproyeksikan data tersebut pada masa mendatang dengan pemodelan matematika. Peramalan digunakan pada PT. Puri Wira Mahkota untuk menentukan kuantitas produk yang seharusnya disediakan oleh unit produksi pusat melalui kantor cabang selaku pihak distributor. Nilai ramalan yang dihasilkan akan ditinjau tingkat akurasinya melalui grafik perbandingan tingkat fluktuasi hasil ramalan dengan data observasi yang diperoleh. Hasil dari model peramalan naif harus menjadi dasar untuk menentukan apakah nilai ramalan dikatakan bagus (akurat). Tidak digunakan untuk menetapkan target peramalan yang bersifat sewenang-wenang (seperti Mean Absolute Percentage Error 10% dikatakan "Sempurna", Mean Absolute Percentage Error 20% dikatakan "Bagus") tanpa adanya konteks kemampuan peramalan dari data observasi. Jika hasil peramalan yang diperoleh lebih buruk dari peramalan naif (berarti dapat dikatakan sebagai hasil ramalan yang "Buruk"), maka jelas proses peramalan perlu ditingkatkan. Hasil yang buruk dan tidak sesuai dengan data aktual tersebut dapat disebabkan oleh beberapa faktor yang kemudian dianalisis untuk peningkatan proses peramalan dengan tujuan memperoleh hasil yang mendekati akurat.


2021 ◽  
Vol 5 (2) ◽  
pp. 517-525
Author(s):  
Moch. Rizal Kurniawan ◽  
Joseph Dedy Irawan ◽  
Febriana Santi Wahyuni

Perkembangan kedai kopi di kota Malang berkembang dengan sangat pesat. Psycoffe merupakan salah satu kedai kopi yang berlokasi di kota Malang. Penelitian dengan judul “Forecasting Penjualan Kopi dengan Metode Exponential Smoothing Berbasis Web (Studi Kasus Kedai Psycoffe)”, memiliki rumusan masalah bagaimana mengimplementasikan Metode Exponential Smoothing untuk forecasting penjualan kopi pada kedai psycoffee dan Bagaimana membuat sebuah sistem berbasis website untuk memprediksi pendapatan dimasa yang akan datang. Tujuan penelitian ini untuk merancang dan membangun aplikasi forescasting penjualan kopi menggunakan metode exponential smoothing pada Kedai Psycoffee berbasis web. Metode yang digunakan dalam penelitian ini adalah metode single exponential smooting. Metode ini merupakan metode yang sangat popular yang digunakan dalam forecasting karena memiliki kinerja yang baik. Metode pengumpulan data dilakukan dengan cara; observasi secara langsung di kedai Psycofe dan juga interview dengan pemilik cafe. Hasil penelitian ini berupa aplikasi forecasting penjualan kopi berbasis website. Efektivitas penerapan aplikasi berbasis web pada kedai psycofe membantu pemilik dalam kedai dalam memprediksi penjualan penjualan di bulan yang akan datang, sehingga pemilik dapat memastikan dengan stock barang sesuai dengan penjualan untuk kedepannya.


2021 ◽  
Vol 5 (2) ◽  
pp. 427-434
Author(s):  
Dwi Bastomi ◽  
Karina Auliasari ◽  
Hani Zulfia Zahro’

Didalam dunia bisnis dan usaha mengharuskan perusahan untuk merancang berbagai macam strategi usaha untuk dapat bertahan. Peramalan atau prediksi inilah yang digunakan sebagai salah satu bahan pertimbangan terutama dalam sektor bisnis dan ekonomi, dimana kerugian suatu perusahaan dapat diminimalisir sebisa mungkin dan keuntungan dapat diraih semaksimal mungkin. Maka dari itu diperlukan suatu perhitungan untuk memprediksi setiap periodenya. Dalam hal ini diterapkan analisis perhitungan metode trend parabolic dan single exponential smoothing dengan nilai alpha 0,1, 0,3, 0,5, 0,7 dan 0,9. Untuk menghitung prediksi penjualan kopi today coffee yang berada di Tulungagung. Kedua metode tersebut dibandingkan untuk mendapatkan nilai akurasi tertinggi (nilai kesalahan terkecil) dengan menggunakan perhitungan MAPE. Data yang digunakan sebagai prediksi adalah data penjualan kopi pada bulan juli 2020 sampai bulan maret 2021. Setelah dilakukan perhitungan didapatkan hasil prediksi menggunakan metode trend parabolic dengan nilai rata-rata MAPE di semua varian rasa sebesar 37,23% dan pada metode single exponential smoothing mendapatkan nilai rata-rata MAPE di semua varian rasa sebesar 54,37%.


2021 ◽  
pp. 75-82
Author(s):  
Ade Bastian ◽  
Diana Surya Heriyana ◽  
Sandi Fajar Rodiansyah

Novel Coronavirus 2019 (COVID-19) is a disease caused by SARS-CoV-2, COVID-19 is a new type of coronavirus that can be transmitted from human to human. This virus can cause pneumonia, which is inflammation of the lung tissue that causes impaired oxygen exchange, resulting in shortness of breath. Currently it is not known when the Covid-19 pandemic will end, therefore a forecast is needed to predict the spread of Covid-19. This forecasting uses the SIR (Susceptible, Infectious, Recovered), Exponential Moving Average and Single Exponential Smoothing algorithm. Of the three algorithms, which data will be most suitable for forecasting the spread of covid-19 in Indonesia will be compared. The conclusion of the SIR model test results with the PSBB variable inhibits the spread of the virus, the exponential moving average test gets an error value of 24.28% and exponential smoothing gets an error value of 40.07%. So the suitable algorithms used for covid-19 data are the sir model and the exponential moving average.


2021 ◽  
Author(s):  
Bethan A Cole ◽  
Nadia Pilati ◽  
Jonathan D Lippiat

Gain-of-function pathogenic missense KCNT1 variants are associated with several developmental and epileptic encephalopathies (DEE). With few exceptions, patients are heterozygous and there is a paucity of mechanistic information about how pathogenic variants increase KNa1.1 channel activity and the behaviour of heterotetrameric channels comprising both wild-type (WT) and variant subunits. To better understand these, we selected a range of variants across the DEE spectrum, involving mutations in different protein domains and studied their functional properties. Whole-cell electrophysiology was used to characterise homomeric and heteromeric KNa1.1 channel assemblies carrying DEE-causing variants in the presence and absence of 10 mM intracellular sodium. Voltage-dependent activation of homomeric variant KNa1.1 assemblies were more hyperpolarised than WT KNa1.1 and, unlike WT KNa1.1, exhibited voltage-dependent activation in the absence of intracellular sodium. Heteromeric channels formed by co-expression of WT and variant KNa1.1 had activation kinetics intermediate of homomeric WT and variant KNa1.1 channels, with residual sodium-independent activity. In general, WT and variant KNa1.1 activation followed a single exponential, with time constants unaffected by voltage or sodium. Mutating the threonine in the KNa1.1 selectivity filter disrupted voltage-dependent activation, but sodium-dependence remained intact. Our findings suggest that KNa1.1 gating involves a sodium-dependent activation gate that modulates a voltage-dependent selectivity filter gate. Collectively, all DEE-associated KNa1.1 mutations lowered the energetic barrier for sodium-dependent activation, but some also had direct effects on selectivity filter gating. Destabilisation of the inactivated unliganded channel conformation can explain how DEE-causing amino acid substitutions in diverse regions of the channel structure all cause gain-of-function.


2021 ◽  
Vol 14 (1) ◽  
pp. 77-82
Author(s):  
Rahmadini Darwas ◽  
Rahimullaily Rahimullaily ◽  
Naufal Abdi

This study aims to determine the estimated number of items sold at one of the mini market, namely the Tita shop, especially Sari Murni cooking oil, 2 liter packs for the next one month based on sales data for January 2016 to December 2017. The problems that occur at Tita`s shop are is difficult to estimate the amount of stock of goods and calculate the estimated cost required for sales in the next month period, so it is necessary to build a forecasting information system using the single exponential smoothing method which assumes that the data fluctuates around the mean value without any trend or seasonal elements. This study resulted in the amount of 2 liter packaged sari murni cooking oil in Januari 2018, which was 42 pcs. Meanwhile, the estimated cost required to buy 2 liter packaged cooking oil stock in that period is Rp. 609.000,00 with a capital price unit of goods Rp. 14.500,00.


2021 ◽  
Vol 6 (2) ◽  
pp. 1-10
Author(s):  
Noreha Mohamed Yusof ◽  
Norani Amit ◽  
Nor Faradilah Mahad ◽  
Noorezatty Mohd Yusop

Forecasting the foreign currency exchange is a challenging task since it is influenced by political, economic and psychological factors. This paper focuses on the forecasting Malaysian Ringgit (MYR) exchange rate against the United States Dollar (USD) using Exponential Smoothing Techniques which are Single Exponential Smoothing, Double Exponential Smoothing, and Holt’s method. The objectives of this paper are to identify the best Exponential Smoothing Technique that describes MYR for 5 years period and to forecast MYR 12 months ahead by using the best Exponential Smoothing Technique. The comparison between these techniques is also made and the best one will be selected to forecast the MYR exchange rate against USD. The result showed that Holt’s method has the smallest value of error measure which depending on the Mean Square Error (MSE) and Mean Absolute Percentage Error (MAPE) for the evaluation part. The MSE is 1.43915x10-14 and MAPE is 2.5413 x 10-6. Meanwhile, the forecast value of MYR in August 2019 is RM 4.30226.


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