scholarly journals Filter Air Bersih Menggunakan Keramik Berpori Studi Kasus di Kabupaten Demak

2021 ◽  
Vol 17 (2) ◽  
pp. 111
Author(s):  
Muhammad Amirur Rokhim

Penggunaan Membran dari keramik akhir-akhir ini di Indonesia mulai meningkat karena membran keramik mempunyai kandungan kimia yang bagus, tahan terhadap panas dan kekuatan yang setabil. penggunaan membran keramik ini semakin meningkat dengan pengaplikasian sebagai filter atau penyaring. Tetapi proses pembuatan dan bahan yang digunakan cukup mahal, maka dari itu penelitian dengan metode mencampurkan bahan lain seperti karbon aktif ini dilakukan, arang tempurung kelapa dan arang sekam padi yang banyak dijumpai mempunyai kemampuan daya serap tinggi (absorpsi) yang baik. Penelitian ini menghadirkan campuran bahan zeolit alam dengan penambahan karbon aktif sebagai bahan campuranya dengan suhu pembakaran 9000C. keramik berpori dibentuk berupa silinder diteliti. Menggunakan Pengukuran densitas dan porositas atau disebut metode arschimides. uji kecepatan alir air dan pengujian nilai TDS (Total Dissolved Solid). Hasil pengujian kandungan Air sebelum disaring dan setelah disaring ICP (inductively coupled plasma) keramik berpori mampu menurunkan nilai-nilai unsur yang terkandung didalam air. hal ini tidak luput dari penggunaan campuran karbon aktif yang terbukti mampu menurunkan kandungan unsur didalam air. serta mampu menurunkan nilai TDS air. laju aliran air juga meningkat sehubungan dengan bertambahnya jumlah campuran karbon aktif yang dilakukan. Dikarenakan semakin banyak pori-pori atau rongga didalam material keramik yang disebabkan oleh terbakarnya karbon aktif disaat proses sintering.

Author(s):  
Bhagavathami Meenaksh ◽  
Chitraa R. Chandran ◽  
Aravindhan Thathchari Ranganathan ◽  
Kavindapadi Venkateswaran Rama ◽  
Valarmathy Srinivasan

Background: This study aims to determine and compare the levels of trace elements copper, zinc, selenium and chromium in GCF and serum of patients with periodontitis and healthy individuals. Methods: This cross sectional study includes 24 study subjects recruited from the patients reporting to the Department of Periodontics , Tagore Dental College Chennai. All the selected patients were subjected to a clinical examination done by a single examiner. The estimation of trace elements Copper, Zinc, Selenium and Chromium in GCF and serum is performed using Perkin Elmer optima 5300 Inductively Coupled Plasma Emission Spectrometer (ICPOES). Results: GCF and serum copper levels showed no significant difference in both periodontitis and healthy groups . Selenium levels tend to be the same in both groups. Serum zinc levels are more in periodontitis patients than healthy subjects (p less than 0.01). GCF chromium levels are found to be more in patients with periodontitis than healthy. Conclusions : More research is therefore needed to monitor the role of these trace elements C with an increased sample size to ascertain whether they are associated with a reduced risk of periodontitis.


2020 ◽  
Author(s):  
Daniel Bůžek ◽  
Slavomír Adamec ◽  
Kamil Lang ◽  
Jan Demel

<div><p>UiO-66 is a zirconium-based metal-organic framework (MOF) that has numerous applications. Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature. The present work therefore assessed the behaviour of UiO-66 in buffers: 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS), 4-(2-hydroxyethyl)piperazine-1-ethane sulfonic acid (HEPES), N-ethylmorpholine (NEM) and phosphate buffer (PB), all of which are commonly used in many UiO-66 applications. High pressure liquid chromatography and inductively coupled plasma mass spectrometry were used to monitor degradation of the MOF. In each buffer, the terephthalate linker was released to some extent, with a more pronounced leaching effect in the saline forms of these buffers. The HEPES buffer was found to be the most benign, whereas NEM and PB should be avoided at any concentration as they were shown to rapidly degrade the UiO-66 framework. Low concentration TRIS buffers are also recommended, although these offer minimal buffer capacity to adjust pH. Regardless of the buffer used, rapid terephthalate release was observed, indicating that the UiO-66 was attacked immediately after mixing with the buffer. In addition, the dissolution of zirconium, observed in some cases, intensified the UiO-66 decomposition process. These results demonstrate that sensitive analytical techniques have to be used to monitor the release of MOF components so as to quantify the stabilities of these materials in liquid environments.</p></div>


2018 ◽  
Author(s):  
Danila Barskiy ◽  
Lucia Ke ◽  
Xingyang Li ◽  
Vincent Stevenson ◽  
Nevin Widarman ◽  
...  

<p>Hyperpolarization techniques based on the use of parahydrogen provide orders of magnitude signal enhancement for magnetic resonance spectroscopy and imaging. The main drawback limiting widespread applicability of parahydrogen-based techniques in biomedicine is the presence of organometallic compounds (the polarization transfer catalysts) in solution with hyperpolarized contrast agents. These catalysts are typically complexes of platinum-group metals and their administration in vivo should be avoided.</p> <p><br></p><p>Herein, we show how extraction of a hyperpolarized compound from an organic phase to an aqueous phase combined with a rapid (less than 10 seconds) Ir-based catalyst capture by metal scavenging agents can produce pure parahydrogen-based hyperpolarized contrast agents as demonstrated by high-resolution nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The presented methodology enables fast and efficient means of producing pure hyperpolarized aqueous solutions for biomedical and other uses.</p>


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