MODERN APPROACHES TO DIAGNOSTICS AND REPAIR OF LOW-POWER SWITCHING POWER SUPPLIES

Рассмотрены вопросы оптимизации технологических процессов поиска и устранения неисправностей маломощных DC-DC преобразователей, изготавливаемых ООО «АЕДОН». Перечислены наиболее характерные неисправности, встречающиеся у импульсных источников питания малой мощности. Рассмотрены основные методы поиска и устранения неисправностей, применяемые в процессе диагностики импульсных преобразователей. Предложен подход, основывающийся на комбинировании различных методов диагностики и ремонта, позволяющий увеличить эффективность поиска и устранения неисправностей импульсных DC-DC преобразователей. Рассматриваемый подход позволил повысить оперативность технической диагностики и ремонта в условиях серийного производства, а также был эффективно использован при первоначальной подготовке молодых специалистов участка регулировки и тестирования. В качестве примера представлена процедура поиска и устранения причин повышенного напряжения холостого хода в маломощных импульсных источниках питания. Рассмотрены причины появления дефекта как в одиночных модулях, так и во всей партии. Проведено экспериментальное исследование влияния обратной связи на выходное напряжение модуля в режиме холостого хода, показано влияние возможных неисправностей. В результате применения данной процедуры в короткий срок была произведена диагностика и ремонт маломощного импульсного источника питания (ИИП), выполнена регулировка обратной связи по напряжению The article considers the issues of optimization of technological processes for troubleshooting low-power DC-DC converters manufactured by company AEDON. We listed the most typical malfunctions that occur in low-power switching power sources. We considered the main methods of troubleshooting used in the process of diagnostics of pulse converters. We propose an approach based on the combination of various diagnostic and repair methods, which allows one to increase the efficiency of troubleshooting of pulsed DC-DC converters. The considered approach allowed us to increase the efficiency of technical diagnostics and repair in the conditions of mass production, and was also effectively used in training of young specialists of the adjustment and testing subdivision. As an example, we present the procedure for finding and eliminating the causes of increased idle voltage in low-power switching power sources. We considered the reasons for the appearance of the defect both in single modules and in the entire batch. We carried out an experimental study of the effect of feedback on the output voltage of the module in the idle mode. We showed the influence of possible failures. As a result of the application of this procedure, we performed diagnostics and repair of a low-power switching power supplies in a short time and adjusted the voltage feedback

Ti/TiO2/SiO2 multilayer thin films with enhanced spectral selectivity for optical narrow bandpass filters

Thin film-based optical sensors have been attracting increasing interest for use in developing technologies such as biometrics. Multilayered dielectric thin films with different refractive indices have been utilized to modulate the optical properties in specific wavelength bands for spectral selectivity of Thin Film Narrow Bandpass Filters (TFNBFs). Progress in TFNBF design has been made with the incorporation of metallic thin films. Narrower bandwidths with higher transmittance have been achieved in specific spectral bands. In this work, Ti/TiO2/SiO2 based multilayer thin films were prepared using pulsed-DC reactive sputtering. Computer simulations using the Essential Macleod Program allowed the optimal number of layers and thickness of the multilayer thin films to be determined to efficiently tailor the optical path transmitting specific wavelength bands. The addition of Ti metal layers within dielectric (TiO2/SiO2) multilayer thin films significantly changes the cutoff frequency of transmittance at specific wavelengths. Representative 26 multilayer films consisting of Ti, TiO2, and SiO2 show lower transmittance of 10.29% at 400 nm and 10.48% at 680 nm. High transmittance of 80.42% at 485 nm was observed, which is expected to improve the spectral selectivity of the TFNBF. This work provides a contribution to future simulation based design strategy based on experimental thin film engineering for potential industrial development opportunities such as optical biometrics.

Neoantigen Dendritic Cell Vaccination Combined with Anti-CD38 and CpG Elicits Anti-Tumor Immunity against the Immune Checkpoint Therapy-Resistant Murine Lung Cancer Cell Line LLC1

An important factor associated with primary resistance to immune-checkpoint therapies (ICT) is a “cold” tumor microenvironment (TME), characterized by the absence of T cell infiltration and a non-inflammatory milieu. Whole-exome and RNA sequencing to predict neoantigen expression was performed on the LLC1 cell line which forms “cold” tumors in mice. Dendritic cell (DC)-based vaccination strategies were developed using candidate neoantigen long peptides (LPs). A total of 2536 missense mutations were identified in LLC1 and of 132 candidate neoantigen short peptides, 25 were found to induce CD8+ T cell responses. However, they failed to inhibit LLC1 growth when incorporated into a cancer vaccine. In contrast, DCs pulsed with LPs induced CD4+ and CD8+ T cell responses and one of them, designated L82, delayed LLC1 growth in vivo. By RNA-Seq, CD38 was highly expressed by LLC1 tumor cells and, therefore, anti-CD38 antibody treatment was combined with L82-pulsed DC vaccination. This combination effectively suppressed tumor growth via a mechanism relying on decreased regulatory T cells in the tumor. This study demonstrated that an appropriate vaccination strategy combining neoantigen peptide-pulsed DC with anti-CD38 antibody can render an ICT-resistant “cold” tumor susceptible to immune rejection via a mechanism involving neutralization of regulatory T cells.

Deposition, Characterization, and Modeling of Scandium-Doped Aluminum Nitride Thin Film for Piezoelectric Devices

In this work, we systematically studied the deposition, characterization, and crystal structure modeling of ScAlN thin film. Measurements of the piezoelectric device’s relevant material properties, such as crystal structure, crystallographic orientation, and piezoelectric response, were performed to characterize the Sc0.29Al0.71N thin film grown using pulsed DC magnetron sputtering. Crystal structure modeling of the ScAlN thin film is proposed and validated, and the structure–property relations are discussed. The investigation results indicated that the sputtered thin film using seed layer technique had a good crystalline quality and a clear grain boundary. In addition, the effective piezoelectric coefficient d33 was up to 12.6 pC/N, and there was no wurtzite-to-rocksalt phase transition under high pressure. These good features demonstrated that the sputtered ScAlN is promising for application in high-coupling piezoelectric devices with high-pressure stability.

Irg1/itaconate metabolic pathway is a crucial determinant of dendritic cells immune-priming function and contributes to resolute allergen-induced airway inflammation

Itaconate is produced from the mitochondrial TCA cycle enzyme aconitase decarboxylase (encoded by immune responsive gene1; Irg1) that exerts immunomodulatory function in myeloid cells. However, the role of the Irg1/itaconate pathway in dendritic cells (DC)-mediated airway inflammation and adaptive immunity to inhaled allergens, which are the primary antigen-presenting cells in allergic asthma, remains largely unknown. House dust mite (HDM)-challenged Irg1−/− mice displayed increases in eosinophilic airway inflammation, mucous cell metaplasia, and Th2 cytokine production with a mechanism involving impaired mite antigen presentations by DC. Adoptive transfer of HDM-pulsed DC from Irg1-deficient mice into naïve WT mice induced a similar phenotype of elevated type 2 airway inflammation and allergic sensitization. Untargeted metabolite analysis of HDM-pulsed DC revealed itaconate as one of the most abundant polar metabolites that potentially suppress mitochondrial oxidative damage. Furthermore, the immunomodulatory effect of itaconate was translated in vivo, where intranasal administration of 4-octyl itaconate 4-OI following antigen priming attenuated the manifestations of HDM-induced airway disease and Th2 immune response. Taken together, these data demonstrated for the first time a direct regulatory role of the Irg1/itaconate pathway in DC for the development of type 2 airway inflammation and suggest a possible therapeutic target in modulating allergic asthma.