NUMERICAL STUDYING ENERGY PARAMETERS OF MULTIELECTRON ATOM IN A MAGNETIC FIELD: HELIUM

There are presented the results of calculating the energies of the helium atom energy in a homogeneous magnetic field on the basis of the new numerical quantum-mechanical approach. The approach is based on the numerical difference solution of the Schrödinger equation, the model potential method and the operator perturbation theory formalism. The obtained results on energy of the helium atom in dependence upon the magnetic field strength are compared with available theoretical results, obtained on the basis of alternative numerical Hartree-Fock and diagonalization methods.

Analisis Daya Saing dan Potensi Ekspor Mobil Indonesia di Kawasan Asia Selatan

Mobil Indonesia berada di peringkat empat sebagai komoditas non-migas dengan nilai ekspor tertinggi. Oleh karena itu, Kementerian Perindustrian meluncurkan program “Making Indonesia 4.0” pada tahun 2018 dimana salah satu targetnya adalah menjadikan Indonesia sebagai pengekspor mobil terbesar di kawasan Asia Tenggara. Berkaitan dengan hal tersebut, daya saing mobil Indonesia di pasar ekspor layak untuk diselidiki. Penelitian ini menganalisis daya saing mobil Indonesia di kawasan Asia Selatan karena selain belum menerapkan peraturan emisi yang ketat, penjualan mobil di kawasan ini mempunyai tren yang positif. Data penelitian adalah data ekspor mobil Indonesia ke empat negara Asia Selatan yaitu Bangladesh, India, Pakistan, dan Sri Lanka periode 2006 – 2019. Data tersebut dianalisis dengan menggunakan tiga metode: Revealed Symmetric Comparative Advantage (RSCA), Export Product Dynamics (EPD), dan X-Model Potential Export Products. Rata-rata indeks RSCA bernilai negatif yang menunjukkan bahwa daya saing mobil Indonesia masih lemah di keempat negara Asia Selatan, tetapi indeks RSCA bernilai positif hanya di Pakistan sejak 2016. Berdasarkan matriks EPD, mobil Indonesia berada di posisi Rising Star di tiga negara kecuali Sri Lanka yang berada pada posisi Falling Star. Analisis X-Model menunjukkan bahwa Bangladesh, India, dan Pakistan merupakan pasar potensial sebagai tujuan ekspor mobil Indonesia meskipun daya saing masih lemah, hanya Sri Lanka yang kurang potensial.

An exploratory study on the microbiome of northern and southern populations of Ixodes scapularis ticks predicts changes and unique bacterial interactions

The black-legged tick (Ixodes scapularis) is the primary vector of Borrelia burgdorferi, the causative agent of Lyme disease in North America. However, the prevalence of Lyme borreliosis is clustered around the northern states of the United States of America. This study utilized a metagenomic sequencing approach to compare the microbial communities residing within Ix. scapularis populations from north and southern geographic locations in the USA. Using a SparCC network construction model, potential interactions between members of the microbial communities from Borrelia burgdorferi-infected tissues of unfed and blood-fed ticks were performed. A significant difference in bacterial composition and diversity among northern and southern tick populations was found between northern and southern tick populations. The network analysis predicted a potential antagonistic interaction between endosymbiont Rickettsia buchneri and Borrelia burgdorferi sensu lato. Network analysis, as expected, predicted significant positive and negative microbial interactions in ticks from these geographic regions, with the genus Rickettsia, Francisella, and Borreliella playing an essential role in the identified clusters. Interactions between Rickettsia buchneri and Borrelia burgdorferi sensu lato needs more validation and understanding. Understanding the interplay between the micro-biome and tick-borne pathogens within tick vectors may pave the way for new strategies to prevent tick-borne infections.

Study of Positron Impact Scattering from Methane and Silane Using an Analytically Obtained Static Potential with Correlation Polarization

A detailed study of positron impact elastic scattering from methane and silane is carried out using a model potential consisting of static and polarization potentials. The static potential for the molecular target is obtained analytically by using accurate Gaussian molecular wavefunctions. The molecular orbitals are expressed as a linear combination of Gaussian atomic orbitals. Along with the analytically obtained static potential, a correlation polarization potential is also added to construct the model potential. Utilizing the model potential, the Schrödinger equation is solved using the partial wave phase shift analysis method, and the scattering amplitude is obtained in terms of the phase shifts. Thereafter, the differential, integrated and total cross sections are calculated. These cross-section results are compared with the previously reported measurements and theoretical calculations.

Designing Aquifer Model for the Banks of the Serayu River, Sokawera, Somagede, Banyumas, Indonesia by Means of 1D-Electrical Resistivity Data

A geoelectric survey using the 1D-electrical resistivity method was applied to design a groundwater aquifer model for the banks of the Serayu River in Sokawera Village, Somagede District, Banyumas Regency, Indonesia. The aim of this research was to identify the characteristics of aquifers in the research area based on resistivity log data. Acquisition, modeling, and interpretation of resistivity data were carried out and the results were lithological logs at seven sounding points. Correlation between the lithological logs resulted in a hydrostratigraphic model. This model is composed of several hydrological units, i.e. shallow aquifer, aquitard, and deep aquifer. The shallow aquifers are composed of sandy clay (10.81-18.21 Wm) and clayey sand (3.04-7.43 Wm) with a depth of groundwater from the water table to 27.51 m. The deep aquifers are composed of sandstone with variation of porosity (2.24-12.04 Wm) at a depth of more than 54.98 m. Based on this model, potential shallow aquifers were estimated to be at sounding points Sch-5, Sch-6, and Sch-7. This hydrostratigraphic model shows that the two types of aquifers are separated by an aquitard layer, allowing groundwater infiltration from the shallow aquifer to the deep aquifer and vice versa. Moreover, the Serayu riverbanks in this research area are estimated to be a groundwater discharge area.