Theoretical view on the origin and implications of structural distortions in polyoxometalates

Structural features of polyoxometalates (POMs) —versatile inorganic clusters of academic and technological interest— are discussed in the present article. POMs are, in general, very regular structures presenting a high symmetry in most cases. Distortions are, however, important for some electronic and magnetic properties. We herein discuss some particular geometric features that are crucial for the theoretical treatment and comprehension of well-known experimental phenomena. For instance, we have been able to understand and rationalize the geometrical distortions present in molybdenum POMs. Moreover, we can affirm that these geometrical distortions are caused by a pseudo Jahn Teller effect. In what concerns NMR chemical shifts, we present a discussion on the importance of geometry for the correct description of the signals and the key role played by the interatomic distances. Finally, a study on the adsorption of Keggin clusters on silver surfaces shows how the POM structure looses its regular shape to adapt to that new situation

SISTEM INFORMASI AKUNTANSI PELAPORAN PENDAPATAN E-TOL PADA PT JASA MARGA (PERSERO) TBK CABANG BELMERA MEDAN

Revenue is an increase in the company's capital that arises as a result of the sale of the company's products. PT. Jasa Marga (Persero) Tbk. Branch is a service company that is engaged in the toll road service provider. Every transaction data enters tolls and income that goes into the company's treasury is still processed using the system computerized, namely with Microsoft Excel. This makes the parties less companies can work more effectively and efficiently so that they can disrupt the work process and result in the reporting process so late. In order to solve this common problem, the author designed a Reporting Accounting Information System Accounting-based E-Toll revenue using Microsoft Visual Basic.Net and the database used is MySQL. With the existence of this system design, the company leadership can accept more accurate and timely income data reports. Besides that with this system also helps admin work much more effectively and efficient.

Optimal navigability of weighted human brain connectomes in physical space

The architecture of the human connectome supports efficient communication protocols relying either on distances between brain regions or on the intensities of connections. However, none of these protocols combines information about the two or reaches full efficiency. Here, we introduce a continuous spectrum of decentralized routing strategies that combine link weights and the spatial embedding of connectomes to transmit signals. We applied the protocols to individual connectomes in two cohorts, and to cohort archetypes designed to capture weighted connectivity properties. We found that there is an intermediate region, a sweet spot, in which navigation achieves maximum communication efficiency at low transmission cost. Interestingly, this phenomenon is robust and independent of the particular configuration of weights.Our results indicate that the intensity and topology of neural connections and brain geometry interplay to boost communicability, fundamental to support effective responses to external and internal stimuli and the diversity of brain functions.Comment: 49 pages (10 main text, 39 Supplementary Material

IDENTIFIKASI FORMALIN PADA BEBERAPA JENIS IKAN ASIN DENGAN MENGGUNAKAN METODE FEHLING A DAN FEHLING B DI PUSAT PASAR KOTA MEDAN TAHUN 2021

Dried fish is a result of the salting and drying process. Low water content in salted fish is due to absorption by salt and evaporation caused by heat from the sun. There are several types of food that are added with additives that are prohibited from being added to food so that the food is more durable and looks better. Food ingredients that use food additives that are not in accordance with the provisions have a direct influence on the degree of human health. Formalin is not a food additive and is prohibited from being added to food. The purpose of the study was to identify the presence or absence of formalin in several types of salted fish which are traded in the market center of Medan city using the Fehling A and Fehling B methods. The place of this research was carried out in the chemical laboratory, USM Indonesia Medan. In the results of research that has been carried out on 20 samples of salted fish, it shows that salted fish samples with codes F5 and F12 contain formalin. The sample codes F5 and F12 gave a red precipitate after being heated which previously added 1 mL of Fehling A and Fehling B and 18 other samples did not show a red precipitate. After observing all samples, there were 2 samples that were positive for formalin from 20 samples of salted fish studied which were declared ineligible in the Regulation of the Minister of Health of the Republic of Indonesia NO.722|MENKES|PER|IX|88 concerning food additives