Transition region ignition characteristics of n-heptane fuel sprays

Ignition studies were perferred on monodisperse n-heptane sprays at atmospheric pressure over a range of equivalence ratios and droplet diameters. A capacitive discharge spark ignition system was used as the ignition source, providing independent control of spark energy and duration. Preliminary measurements were made to optimize spark duration and spark gap, optimum conditions being those at which the maximum frequency or probability of ignition was observed. The effect of spark duration on ignition frequency for several spark energies was determined for equivalence ratios of 0.5 and 1.0 and initial droplet diameters of 28 and 68 microns. Spark duration had little effect on ignition frequency over the entire 15 to 170 mu s range examined. Spark durations of 70 to 80 mu s were used for all subsequent work. The spark gap was optimized at equivalence ratios of 0.6, 0.8 and 1.0 and initial droplet diameters of 30, 40, 50, 60 and 70 microns by varying the electrode spacing from 0.5 to 5.0 mm while maintaining a constant spark energy. The optimum gap was determined to be 3.0 mm for nearly all conditions

Nanoskyrmion engineering with spsp-electron materials: Sn monolayer on SiC(0001) surface

Materials with $sp$-magnetism demonstrate strongly nonlocal Coulomb interactions, which opens a way to probe correlations in the regimes not achievable in transition metal compounds. By the example of Sn monolayer on SiC(0001) surface, we show that such systems exhibit unusual but intriguing magnetic properties at the nanoscale. Physically, this is attributed to the presence of a significant ferromagnetic coupling, the so-called direct exchange, which fully compensates ubiquitous antiferromagnetic interactions of the superexchange origin. Having a nonlocal nature, the direct exchange was previously ignored because it cannot be captured within the conventional density functional methods and significantly challenges ground state models earlier proposed for Sn/SiC(0001). Furthermore, heavy adatoms induce strong spin-orbit coupling, which leads to a highly anisotropic form of the spin Hamiltonian, in which the Dzyaloshinskii-Moriya interaction is dominant. The latter is suggested to be responsible for the formation of a nanoskyrmion state at realistic magnetic fields and temperatures.Comment: 4 pages, supplemental materia

Strong electron-phonon coupling and phonon-induced superconductivity in tetragonal C3_3N4_4 with hole doping

C$_3$N$_4$ is a recently discovered phase of carbon-nitrides with the tetragonal crystal structure (arXiv:2209.01968) that is stable at ambient conditions. C$_3$N$_4$ is a semiconductor exhibiting flat-band anomalies in the valence band, suggesting the emergence of many-body instabilities upon hole doping. Here, using state-of-the-art first-principles calculations we show that hole-doped C$_3$N$_4$ reveals strong electron-phonon coupling, leading to the formation of a gapped superconducting state. The phase transition temperatures turns out to be strongly dependent on the hole concentration. We propose that holes could be injected into C$_3$N$_4$ via boron doping which induces, according to our results, a rigid shift of the Fermi energy without significant modification of the electronic structure. Based on the electron-phonon coupling and Coulomb pseudopotential calculated from first principles, we conclude that the boron concentration of 6 atoms per nm$^3$ would be required to reach the critical temperature of $\sim$55 K at ambient pressure.Comment: 10 pages incl. Supplemental Material, 8 figure

Magnetism of coupled spin tetrahedra in ilinskite-type KCu5_{5}O2_2(SeO3_3)2_2Cl3_3

Synthesis, thermodynamic properties, and microscopic magnetic model of ilinskite-type KCu$_{5}$O$_2$(SeO$_3$)$_2$Cl$_3$ built by corner-sharing Cu$_4$ tetrahedra are reported, and relevant magnetostructural correlations are discussed. Quasi-one-dimensional magnetic behavior with the short-range order around 50\,K and the absence of long-range order down to at least 2\,K is observed experimentally and explained in terms of weakly coupled spin ladders (tubes) with a complex topology formed upon fragmentation of the tetrahedral network. This fragmentation is rooted in the non-trivial effect of the SeO$_3$ groups that render the Cu--O--Cu superexchange strongly ferromagnetic.Comment: 9 pages, 7 figure

Cutting Conditions and Surface Integrity During Dry Plunge-milling of a Wrought Magnesium Alloy

AbstractPlunge milling is a machining process used to remove material rapidly in roughing operations. It is known to offer significant increases in productivity as compared with conventional milling, especially in the case of deep milled workpieces. However, high productivity also entails the increase in machining conditions so it would be expected that plunge milling has more impact on surface integrity than conventional machining. In this study the authors consider the case of a dry plunge milling process applied to a wrought Mg-Zr-Zn-RE alloy. First, the study involves obtaining surfaces through experimental design. Second, plunge milling conditions are correlated with surface integrity factors, such as roughness, microstructure and microhardness. This study suggests plunge milling conditions to offer a trade-off between surface integrity and chip flow

EVALUASI PEMBELAJARAN PENDIDIKAN JASMANI, OLAHRAGA DAN KESEHATAN MENGGUNAKAN MODEL FORMATIF DAN SUMATIF

Dalam satu semester pembelajaran pendidikan jasmani, olahraga dan kesehatan selalu dilakukan evaluasi untuk mengetahui keberhasilan yang telah dicapai oleh peserta didik. Evaluasi yang digunakan dalam satu semester yaitu menggunakan evaluasi formatif (tes yang dialukan ketika akhir pelajaran/proses belajar mengajar) dengan tujuan guru mengontrol peserta didik mengenai materi yang telah diajarkan pada pokok bahasan tersebut, dan evaluasi sumatif (tes yang dilakukan setiap akhir semester/hasil penilaian) dengan tujuan untuk melihat hasil pembelajaran yang telah dikuasai oleh para peserta didik

Fast and low cost analysis of dioxin and dioxin-like compounds in marine matrices: final report

0info:eu-repo/semantics/publishe

Sistem Informasi Harga Pokok Proses Bagi USAha Kecil Dan Menengah Dalam Meningkatkan Kualitas Proses Produksi

Accounting Information Systems today has an important role to the progress of an organization included in the business world. The problem that often arises in small and medium enterprises, among others on the system transactions are still done manually, by relying on paper for archiving enterprise data. Of course, such things will be difficult to control and report transaction data namely finance Production Cost and Process Cost. An application system that can help the process along with the transaction data report is required which can present useful information for interested parties to address such problems. The fact that there are still many small and medium-class companies (SMEs) still doing transaction processing, financial records and preparing reports both reports transactions and financial statements of the company manually. Improving the IT mastering is one of the important factors that need to be considered for small and medium enterprises and it also can develop the business wheel. IT development has been moving very rapidly, both in terms of hardware and software which can help the company\u27s performance.One of SMEs in Kebumen district is tile company famous brand of Sokka. Most companies tile in the district Kebumen still use manual accounting system. Tile Company Brands Sokka does the production process using the production machine. Where the process Brands Sokka tile production company produces several kinds of products in the form types of tile press generated from period to period is always the same.The existence of accounting information system is expected to make management transactions and corporate finance better and accurate, and can help entrepreneurs and policy makers in managing the company\u27s finances and taking policy\u27s company as well as scoring at the performance of the company. Therefore, the authors apply a Cost Information System applications Process For Small And Medium Enterprises In Improving the Quality of Production Process using microsoft office 2007 program

Potensi Nano Analog RN-18 (NARN-18) Berbasis Nanopartikel PLGA-CS-PEG dalam Penatalaksanaan HIV-1

Acquired Immune Deficiency Syndrome (AIDS) is the cause of death of million people in the world in 2016. The prevalence of Human Immunodeficiency Virus-1 (HIV-1) infection in Indonesia is still high and number of death caused by HIV-1-related diseases shows an apprehensive number. Treatment of HIV/AIDS nowadays is not effective to eradicate HIV-1 and also cause adverse effects. Previous research found RN-18 as a specific antagonistic molecule for viral infectivity factor (Vif) that can trigger Vif degradation and maintain intracellular A3G level. The aim of this review is to examine the potential of NARN-18 based PLGA-CS-PEG nanoparticles through oral administration in the management of HIV-1 infection. Method of this article is using literature review method. Literature searching is done by using “A3G”, “HIV-1”, “PLGA-CS-PEG”, “RN-18”, and “Vif” as keywords in search engine. 13a molecule, that is the analogue of RN-18, is used in the modality because it has better effectiveness and solubility compared with RN-18. By using PLGA, PEG, and chitosan (CS) as nanoparticles that carries RN-18 analogue makes the modality can be taken orally and targets T cell as soon as it enters the blood stream. It also can increase the efficiency of drug release and drug loading of the modality. NARN-18 constructed by using PLGA-PEG-CS nanoparticle makes the modality can be administered orally, increase its half-life in the body, and also increase the inhibition effect of RN-18 analogue. Therefore, this combination is one of the potential therapy in HIV-1 infection treatment