scholarly journals Perhitungan Energi Disosiasi Gugus Fungsi OH- dan PO43- Hidroksiapatit dengan Pemodelan Spektroskopi Inframerah Berbasis Particle Swarm Optimization (PSO)

2016 ◽  
Vol 3 (01) ◽  
pp. 86 ◽  
Author(s):  
Khusnul Yakin ◽  
Sidikrubadi Pramudito ◽  
Kiagus Dahlan
Keyword(s):  
Functional Groups ◽  
Dissociation Energy ◽  
Functional Group ◽  
Spring Constant ◽  
Wave Number ◽  
Swarm Optimization ◽  
Group Modeling ◽  
Phosphate Compound ◽  
Spring Constants ◽  
Absorption Wave

<span>Hydroxyapatite Ca<span>10<span>(PO<span>4<span>)<span>6<span>(OH)<span>2 <span>is a calcium phosphate compound having biocompatibility <span>properties. FTIR (Fourier Transform Infrared Spectroscopy) was used to determine the <span>characteristics of the hydroxyapatite group. Modeling the functional groups of hydroxyapatite <span>can be used to obtain vibrational frequencies and spring constants. Analysis of energy release <span>function is performed by calculating the dissociation energy. In this paper will be shown the <span>results of theoretical modeling of hydroxyl and phosphate using spring models. Modeling the <span>functional groups OH<span>- <span>obtained spring constant 524,4559 N/m and the absorption wave number <span>3497,5677 cm<span>-1<span>. Modelling functional groups PO<span>43-<span>obtained spring constant 612,2704 N/m <span>and the wave number 1085,2559 cm<span>-1 <span>absorption. The constant and absorption wave numbers <span>obtained are used to calculate the dissociation energy. OH<span>- <span>dissociation energy obtained by <span>566,5637 kJ/mol and the dissociation energy of PO<span>43- <span>is 567,6248 kJ/mol. Absorption wave <span>numbers are obtained in accordance with experimental results on sometrik stretch modes, and <span>the dissociation energy derived functional group is also close to the value of literature.</span></span></span></span></span></span></span></span></span></span></span></span><br /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

scholarly journals PENGARUH VARIASI TEMPERATUR KALSINASI TERHADAP BARIUM M-HEKSAFERIT DIDOPING Zn MENGGUNAKAN FOURIER TRANSFORM INFRA RED

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Aris Doyan ◽  
Ilham Halik ◽  
Susilawati Susilawati
Keyword(s):  
Magnetic Material ◽  
Fourier Transform ◽  
Functional Groups ◽  
Functional Group ◽  
Powder Sample ◽  
Wave Number ◽  
Synthesis Process ◽  
Infra Red ◽  
Test Result ◽  
Brown Powder

Abstrak: Barium M-heksaferit (BaM) merupakan bahan magnet permanen yang tergolong hardmagnetic tetapi tidak sesuai untuk beberapa aplikasi, sehingga perlu dilakukan rekayasa untuk menurunkan sifat kemagnetannya menjadi softmagnetic. Penelitian ini bertujuan untuk mengetahui pengaruh temperatur kalsinasi terhadap barium M-heksaferit didoping Zn menggunakan pengukuran FTIR. Proses sintesis barium M-heksaferit menggunakan metode kopresipitasi dengan memvariasikan konsentrasi dopannya 0,0; 0,3; 0,6; dan 0,9 serta memvariasikan temperatur kalsinasi 80oC, 400oC, 600oC dan 800oC. Setelah melakukan proses sintesis selanjutnya dilakukan pengujian sampel menggunakan FTIR (Fourier Transform Infra Red). Penelitian ini telah berhasil melakukan sintesis dengan hasil berupa serbuk barium M-heksaferit berwarna coklat muda hingga coklat tua. Berdasarkan hasil pengujian FTIR didapatkan puncak-puncak pada bilangan gelombang 3447cm-1, 2345cm-1, 1615cm-1, 530cm-1, 470cm-1 masing-masing mengindikasikan adanya gugus fungsi O-H, Ba-O, Fe-O dan Zn-O pada sampel. Puncak yang timbul pada ikatan O-H semakin mengecil menandakan bahwa ikatan pada gugus fungsi tersebut semakin melemah atau bahkan hilang. Hasil pengujian FTIR tersebut menyatakan bahwa temperatur kalsinasi sangat berpengaruh pada proses sintesis BaM. Semakin tinggi temperatur kalsinasi, bahan pengotor seperti air dan CO pada barium M-heksaferit semakin berkurang, ini menunjukkan barium M-heksaferit yang dihasilkan dapat digunakan sebagai bahan softmagnetic.Kata Kunci: Barium M-Heksaferite, sintesis, kopresipitasi, magnet, FTIR Abstract: Barium M-hexaferrite (BaM) is a permanent magnetic material which is relatively hardmagnetic but it is not appropriate for some applications that need to be engineered to degrade the nature of  magnetism to be softmagnetic. This study aims to determine the effect of calcinations temperature on Zn doped BaM using FTIR measurements. Synthesis of BaM using coprecipitation method by varying the concentrate of dopan 0,0; 0,3; 0,6; dan 0,9 and varying the calcinations temperature 80oC, 400oC, 600oC dan 800oC. After synthesis of BaM and than the samples were studied using FTIR (Fourier Transform Infra Red). This study has success to synthesis of BaM and the product is a brown powder. Based on the test result of FTIR has been obtained peaks in wave number 3447cm-1, 2345cm-1, 1615cm-1, 530cm-1, 470cm-1 indicated a functional group O-H, Ba-O, Fe-O dan Zn-O on the powder sample. The peak on O-H shrinking indicates that the bond of functional groups are weakened or even disappear.The result of FTIR said that calcinations temperature has effect to BaM synthesis process. It is found that water and CO decrease with increase in calcinations temperature, it is showed the product BaM can be used to softmagnetic.Key Words : Barium M-Hexaferrites, synthesis, coprecipitasi, magnet, FTIR

scholarly journals Resilience of Epiphytic Lichens to Combined Effects of Increasing Nitrogen and Solar Radiation

2021 ◽  
Vol 7 (5) ◽  
pp. 333
Author(s):  
Lourdes Morillas ◽  
Javier Roales ◽  
Cristina Cruz ◽  
Silvana Munzi
Keyword(s):  
Global Change ◽  
Solar Radiation ◽  
Functional Groups ◽  
Physiological Response ◽  
Functional Group ◽  
Environmental Drivers ◽  
Combined Effects ◽  
Environmental Stressor ◽  
Comprehensive Understanding ◽  
Direct Sunlight

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.

The Appropriate Lumped Constants of Vibrating Shaft Systems

1943 ◽  
Vol 10 (4) ◽  
pp. A220-A224
Author(s):  
G. Horvay ◽  
J. Ormondroyd
Keyword(s):  
Total Mass ◽  
Spring Constant ◽  
New Method ◽  
Concentrated Mass ◽  
Shaft System ◽  
Spring Constants

Abstract The present paper is a theoretical supplement to the descriptive article, “Static and Dynamic Spring Constants.” It is concerned with the derivation of the constants (1a)Ki=ki+16miω2=ki(1+16ϵi2)(ϵi2=ω2mi/ki)(1b)Mi=μi+12(mleft+mright) of the appropriately lumped shaft system (Section 1), and with an estimate of the range of the new method (Sections 2, 3, 4). Term ki denotes the distributed static spring constant, mi the total mass of the ith (uniform) shaft section of the system; μi is the ith concentrated mass, ω the frequency of vibration.

scholarly journals Food Additives Frequency in processed baby products in Cochabamba, Bolivia

2021 ◽  
Vol 17 (Especial) ◽  
pp. 19-27
Author(s):  
Nelcy Aguilar Sasari ◽  
Milenka Alessandra Fernández Ledezma ◽  
Tania Araujo-Burgos
Keyword(s):  
Shelf Life ◽  
Functional Groups ◽  
Frequency Analysis ◽  
Metropolitan Area ◽  
Sodium Nitrate ◽  
Functional Group ◽  
Food Additives ◽  
Processed Food ◽  
Food Labels ◽  
Organoleptic Properties

Additives are necessary substances to improve the nutritional and organoleptic properties and the shelf life of processed food. In addition, their use is regulated, and it must be declared on the food labels. Thus, the objective of this research was to determine the frequency of food additives in processed baby products in Cochabamba metropolitan area (Bolivia). Data were collected by label reading and a frequency analysis was performed by additives and by functional group. 26 baby products were found where 41 food additives were identified with an occurrence of 256 times, and a mean of 9,8 additives per product. Moreover, the functional groups most widely used are antioxidants and colorants. Finally, the most frequent additives are mostly harmless, except for sodium nitrate and copper sulfate.

scholarly journals Phytochemical Screening, Spectrum Profile of Functional Groups, and Effervescent Formulation of Kepok Banana Peels Stem Extract

2021 ◽  
Vol 4 (2) ◽  
pp. 66-72
Author(s):  
Robby Candra Purnama ◽  
Annisa Primadiamanti
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Secondary Metabolites ◽  
Functional Groups ◽  
Functional Group ◽  
Screening Method ◽  
Phytochemical Screening ◽  
Stem Extract ◽  
Group Profile ◽  
Banana Stem

Kepok banana plants contain secondary metabolites such as tannins and flavonoids. Tannins and flavonoids have various properties for human health. Research has been carried out to identify secondary metabolite compounds (tannins, flavonoids, and saponins) by using the phytochemical screening method to see the functional group profile contained in the extract of kepok banana stem waste. Kepok banana stem waste was extracted in 96% ethanol, then evaporated and screened phytochemically. This extract was used to prepare effervescently. Screening results showed that tannin and flavonoids were identified by the appearance of the following color black-green and dark red, respectively. Meanwhile, saponins were negative because the foam formed had a height of 0.3 cm and did not meet the saponins' positive requirements (1-3 cm high foam and stable for 5 minutes). Identification of functional groups in the extract of kepok banana stem waste using Fourier-transform Infrared Spectroscopy (FTIR) showed that C-C stretching in the area 2927.24 cm-1, O-H stretching in the 3423.87 cm-1 area, C=O stretching in the 1648.87 cm-1 area. Also appeared bending CH2 in the region of 1421.45 cm-1, and C-C in the area of 1149.98 cm-1. The characteristics of three different formulas (A, B, and C) of effervescent have been investigated: the moisture content of 2.51%; 2.55%, and 2.52%, respectively. Then, flow rate of 8.81 g/s; 8.83 g/s; and 8.82 g/s, compressibility of 14.5%; 14.4%; and 14.5%, and a pH of 5.97; 5.98; and 5.97 respectively. All parameters are eligible.

scholarly journals Functional Group Identification for FTIR Spectra Using Image-Based Machine Learning Models

2021 ◽  
Author(s):  
Abigail Enders ◽  
Nicole North ◽  
Chase Fensore ◽  
Juan Velez-Alvarez ◽  
Heather Allen
Keyword(s):  
Machine Learning ◽  
Gas Phase ◽  
Functional Groups ◽  
Functional Group ◽  
Spectroscopic Method ◽  
Group Identification ◽  
Spectroscopic Technique ◽  
Ftir Spectra ◽  
Spectral Interpretation ◽  
Time Required

<p>Fourier Transform Infrared Spectroscopy (FTIR) is a ubiquitous spectroscopic technique. Spectral interpretation is a time-consuming process, but it yields important information about functional groups present in compounds and in complex substances. We develop a generalizable model via a machine learning (ML) algorithm using Convolutional Neural Networks (CNNs) to identify the presence of functional groups in gas phase FTIR spectra. The ML models will reduce the amount of time required to analyze functional groups and facilitate interpretation of FTIR spectra. Through web scraping, we acquire intensity-frequency data from 8728 gas phase organic molecules within the NIST spectral database and transform the data into images. We successfully train models for 15 of the most common organic functional groups, which we then determine via identification from previously untrained spectra. These models serve to expand the application of FTIR measurements for facile analysis of organic samples. Our approach was done such that we have broad functional group models that inference in tandem to provide full interpretation of a spectrum. We present the first implementation of ML using image-based CNNs for predicting functional groups from a spectroscopic method.</p>

scholarly journals ANALISIS KONDUKTIVITAS DAN TERMAL PADA POLIMER ELEKTROLIT DARI KITOSAN/PVA/GLISEROL/LiClO4 UNTUK APLIKASI BATERAI ION LITIUM

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nurhadini . ◽  
Verry Andre Fabiani ◽  
Megawati Ayu Putri ◽  
Iin Lestari
Keyword(s):  
Thermal Stability ◽  
Polymer Electrolyte ◽  
Functional Group ◽  
Raw Materials ◽  
Lithium Ion ◽  
Electrolyte Composition ◽  
Wave Number ◽  
Natural Polymers ◽  
Casting Method ◽  
Absorption Intensity

Penggunaan polimer ramah lingkungan merupakan tantangan bagi industri baterai ion litium saat ini dikarenakan sifatnya yang mudah terbiodegradasi menjadi keunggulan polimer alam seperti kitosan dengan bahan baku dari alam yang melimpah. Komposisi polimer elektrolit dalam penelitian ini terdiri atas kitosan, PVA, gliserol yang didopan dengan LiClO4. Penelitian ini bertujuan untuk menganalisis sifat konduktivitas dan termal dari polimer elektrolit kitosan/PVA/gliserol/LiClO4. Pembuatan polimer elektrolit ini menggunakan metode casting. Peningkatan massa kitosan dalam komposisi polimer elektrolit menyebabkan adanya peningkatan intensitas pada bilangan gelombang 1718 cm-1 dan peningkatan intensitas serapan pada bilngangan gelombang 1271 cm-1 dengan masing-masing puncak serapan tersebut adalah gugus fungsi dari C=O dan gugus fungsi C-O.  Berdasarkan data konduktivitas menunjukkan bahwa komposisi 70/30/20/20 (kitosan /PVA/Gliserol/LiClO4) memiliki konduktivitas tertinggi sebesar 4,8 x 10-5S/cm. Hasil kurva TGA menunjukkan stabilitas termal komposisi polimer elektrolit hingga 210oC dan peningkatan jumlah kitosan dalam polimer elektrolit menurunkan kestabilan termal. Polimer elektrolit dari kitosan/PVA/Gliserol/LiClO4 dapat diaplikasikan untuk baterai ion litium berdasarkan analisis konduktivitas ionik dan kestabilan termal. ABSTRACT The use of environmentally friendly polymers is a challenge for the lithium-ion batteries industry today because its biodegradable nature is an advantage of natural polymers such as chitosan with abundant raw materials from nature. The polymer electrolyte composition in this study consisted of chitosan, PVA, glycerol doped with LiClO4. This study aims to analyze the conductivity and thermal properties of the polymer electrolyte chitosan/PVA/Glycerol/LiClO4. The polymer electrolyte was made using a casting method. The increasing of the chitosan mass in the polymer electrolyte composition led to an increase in intensity at the wave number 1718 cm-1 and an increase in absorption intensity at the wavenumber of 1271 cm-1 with absorption peaks being a functional group of C=O and C-O respectively. Based on the conductivity data, it showed that the composition of 70/30/20/20 (chitosan/PVA/Glycerol/LiClO4) had the highest conductivity of 4.8 x 10-5S/cm. The results of the TGA curve illustrated that polymer electrolyte had thermal stability until 210oC and the increasing amount of chitosan of polymer electrolyte decreased thermal stability. Polymer electrolyte chitosan

scholarly journals Fish functional groups in a tropical wetland of the Yucatan Peninsula, Mexico

2016 ◽  
Vol 14 (2) ◽  
Author(s):  
Fernando Córdova-Tapia ◽  
Luis Zambrano
Keyword(s):  
Functional Groups ◽  
Functional Group ◽  
Group Structure ◽  
Environmental Filtering ◽  
Dry Season ◽  
Freshwater Wetland ◽  
Wet Season ◽  
Major Step ◽  
Natural Habitats ◽  
Niche Complementarity

ABSTRACT The characterization of species' functional traits is a major step in the understanding and description of communities in natural habitats. The classification of species into functional groups is a useful tool to identify redundancy and uniqueness. We studied the fish community of a pristine freshwater wetland in the Sian Ka'an Biosphere Reserve by analysing two multidimensional functions: food acquisition and locomotion. We investigated changes in the functional group structure between habitats (permanent and temporary pools) and seasons (dry and wet). Six functional groups with different ecological characteristics were detected, two of which had high functional redundancy and three of them were represented by single species with unique ecological functions. In permanent pools during the dry season, functional group richness and diversity were lower, while evenness was higher. During the wet season, all functional groups were detected and similar functional group structure was found between habitats. These results suggest an effect of environmental filtering during the dry season and niche complementarity during the wet season.

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