scholarly journals International Journal of Chemical & Material Sciences

2019 ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Erma Ayu Nurcahyani ◽  
Merkuria Karyantina ◽  
Nanik Suhartatik

Ikan asin adalah metode untuk pengawetan makanan menggunakan kombinasi penggaraman dan pengeringan matahari. Di kalangan masyarakat, pembuatan ikan asin banyak menggunakan bahan kimia berbahaya seperti formalin. Penambahan bahan berbahaya mempengaruhi kualitas terutama keamanan. Makanan yang aman didefinisikan sebagai makanan yang terbebas dari cemaran biologi, kimia, mikrobiologi, yang dapat mempengaruhi kesehatan. Karbon aktif diduga bersifat polar yang mampu mengadsorpsi formalin. Tujuan penelitian ini adalah untuk mengetahui pengaruh pemberian karbon aktif dalam mengurangi cemaran formalin pada “jambal roti”. Rancangan percobaan yang digunakan untuk percobaan yaitu Rancangan Acak Lengkap (RAL) 2 faktorial, dengan faktor pertama yaitu konsentrasi karbon aktif 0, 3, dan 6% serta perlakuan kedua yaitu lama perebusan selama 5, 10, dan 15 menit. Penelitian ini dimulai dari pembuatan “jambal roti” dengan penambahan formalin dan perebusan dengan karbon aktif kemudian dianalisis uji kadar formalin, NaCl, protein, dan air. Hasil penelitian menunjukkan bahwa konsentrasi karbon aktif dan lama perebusan memberikan pengaruh yang signifikan pada kualitas jambal roti. Semakin tinggi konsentrasi karbon aktif dan lama perebusan maka semakin berkurangnya kadar formalin pada jambal roti. Hasil terbaik penelitian ini adalah karbon aktif 6% dan lama perebusan 15 menit. Menghasilkan formalin 3.21 ppm, NaCl 9.40%, protein 42.00%, dan air 30.02%. Kata kunci: Karbon Aktif, Formalin, Jambal Roti, Lama Perebusan. ABSTRACT                 Salted fish was a method for food preservation using combination of salting and sun drying. Among the people, the manufacture of salted fish use hazardous chemical material such as formaldehyde. The addition of hazardous substances affects the quality especially the safety. Safe food define as food that free from biological, chemical, microbiological contaminants that can affect health. Active carbon suspected to be polar which able to adsorb formaldehyde. The purpose of this research was to determine the influence of active carbon in reducing formaldehyde in salted fish “jambal roti”. The research used completely randomized design (CRD) with 2 factors, the first factor was the concentration of active carbon 0, 3, and 6% and the second was the boiling time (for 5, 10, and 15 min). This research was started from making “jambal roti” with the addition of formaldehyde and boiling with active carbon then analyzed for formaldehyde content, NaCl, protein, and moisture. The result showed that the concentration of active carbon and boiling time had a significant effect in quality salted fish “jambal roti”. The higher the concentration of active carbon and boiling time the more formaldehyde in “jambal roti” were removed. The best results of the research was 6% active carbon and 15 min of boiling time. Resulting 3.21 ppm of formaldehyde, 9.40% of NaCl, 42.00% of protein, and 30.02% of moisture. Keywords: Active Carbon, Formaldehyde, Jambal Roti, Boiling Time


2019 ◽  
Vol 9 (4) ◽  
pp. 43-52
Author(s):  
Ryzal Perdana ◽  
◽  
◽  

Abstract Critical and creative thinking skills are an essential attribute for success in the 21st century. This study aimed to determine the students’ critical and creative thinking skills in the Islamic senior high schools of Surakarta City so that teachers can pay attention to the strength and weakness of each student based on gender differences. This study used descriptive qualitative analysis. The subject of this study amounted to 180 students consisting of 80 male and 100 female students. The measurement of critical-thinking skills used a 6-essay-question instrument of the chemical material of electrolyte and non-electrolyte solutions that measures the aspects based on Facione theory, namely: analysis, inference, explanation, interpretation, evaluation, and self-regulation. Then, to measure creative-thinking skills, a 4-essay-question test instrument of the chemical material that includes 4 aspects according to Torrance, fluency, flexibility, original and elaboration, was used. The results showed that the creative-thinking skills of male students are better than those of female students and the critical-thinking skills of female students are better than those of male students.


2021 ◽  
Vol 35 (2) ◽  
pp. 209-222
Author(s):  
Dylan Serillon ◽  
Carles Bo ◽  
Xavier Barril

AbstractThe design of new host–guest complexes represents a fundamental challenge in supramolecular chemistry. At the same time, it opens new opportunities in material sciences or biotechnological applications. A computational tool capable of automatically predicting the binding free energy of any host–guest complex would be a great aid in the design of new host systems, or to identify new guest molecules for a given host. We aim to build such a platform and have used the SAMPL7 challenge to test several methods and design a specific computational pipeline. Predictions will be based on machine learning (when previous knowledge is available) or a physics-based method (otherwise). The formerly delivered predictions with an RMSE of 1.67 kcal/mol but will require further work to identify when a specific system is outside of the scope of the model. The latter is combines the semiempirical GFN2B functional, with docking, molecular mechanics, and molecular dynamics. Correct predictions (RMSE of 1.45 kcal/mol) are contingent on the identification of the correct binding mode, which can be very challenging for host–guest systems with a large number of degrees of freedom. Participation in the blind SAMPL7 challenge provided fundamental direction to the project. More advanced versions of the pipeline will be tested against future SAMPL challenges.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 471
Author(s):  
Eleonora Tosi ◽  
Renata Marcia de Figueiredo ◽  
Jean-Marc Campagne

The crucial role played by compounds bearing amide functions, not only in biological processes but also in several fields of chemistry, life polymers and material sciences, has brought about many significant discoveries and innovative approaches for their chemical synthesis. Indeed, a plethora of strategies has been developed to reach such moieties. Amides within chiral molecules are often associated with biological activity especially in life sciences and medicinal chemistry. In most of these cases, their synthesis requires extensive rethinking methodologies. In the very last years (2019–2020), enantioselective C-H functionalization has appeared as a straightforward alternative to reach chiral amides. Therein, an overview on these transformations within this timeframe is going to be given.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4499
Author(s):  
Xiao Hu ◽  
Samuel Ricci ◽  
Sebastian Naranjo ◽  
Zachary Hill ◽  
Peter Gawason

Electrically responsive biomaterials are an important and emerging technology in the fields of biomedical and material sciences. A great deal of research explores the integral role of electrical conduction in normal and diseased cell biology, and material scientists are focusing an even greater amount of attention on natural and hybrid materials as sources of biomaterials which can mimic the properties of cells. This review establishes a summary of those efforts for the latter group, detailing the current materials, theories, methods, and applications of electrically conductive biomaterials fabricated from protein polymers and polysaccharides. These materials can be used to improve human life through novel drug delivery, tissue regeneration, and biosensing technologies. The immediate goal of this review is to establish fabrication methods for protein and polysaccharide-based materials that are biocompatible and feature modular electrical properties. Ideally, these materials will be inexpensive to make with salable production strategies, in addition to being both renewable and biocompatible.


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
Jie Zhang ◽  
Zhiming Zhang ◽  
Fulin Yang ◽  
Haoke Zhang ◽  
Jingzhi Sun ◽  
...  

Novel polymerizations based on alkyne monomers are becoming a powerful tool to construct polymers with unique structures and advanced functions in the areas of polymer and material sciences, and scientists have been attracted to develop a variety of novel polymerizations in recent decades. Therein, catalytic systems play an indispensable role in the influence of polymerization efficiencies and the performances of the resultant polymers. Concerning the shortcomings of metallic catalysts, much of the recent research focus has been on metal-free polymerization systems. In this paper, metal-free catalysts are classified and the corresponding polymerizations are reviewed, including organobase-catalyzed polymerizations, Lewis-acid-catalyzed polymerizations, as well as catalyst-free polymerizations. Moreover, the challenges and perspectives in this area are also briefly discussed.


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