AGRIS - 

2024

Vilniškis, Tomas | Januševičius, Tomas

In this study, the insertion loss of devulcanized waste rubber baffles were evaluated. Acoustic baffles are suitable to reduce noise from the devices or machines by interfering with their emitting sound waves. Knowledge of the acoustic properties of the material used is of significant importance in ensuring the effectiveness of the acoustic properties of the baffle. Basic properties include airborne sound insulation, which is usually determined during laboratory tests. Baffles consists of sound absorbing and sound insulating materials. In this study, plasterboards were used as sound insulating material and devulcanized waste rubber as sound absorbing material. During the devulcanization process, porous granules are obtained, which can be used as an acoustic material. In this study, two types of rubber granules were devulcanized by grinding method and one other type was chemically devulcanized. Three types of rubber granules were mixed together in increasing 25 % proportion steps and glued with patented polyurethane glue. A total of 15 different composition devulcanized waste rubber granule boards were made. Rubber boards were attached together with the plasterboards. Insertion loss of the different composite baffles was measured in semi-anechoic chamber in a purposefully designed stand in 1/3rd octave bands. The results showed that the insertion loss of the baffles was mostly dependent on the rubber granule board density. When the density of the rubber board increased, the insertion loss also increased. The 5–6 dB insertion loss difference was measured bet ween the most and least dense rubber granule board baffles.

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Fundamental Library of Latvia University of Life Sciences and Technologies - Latvia

2024

Célia Dupain | Tom Gutman | Elodie Girard | Choumouss Kamoun | Grégoire Marret | Zahra Castel-Ajgal | Marie-Paule Sablin | Cindy Neuzillet | Edith Borcoman | Ségolène Hescot | Céline Callens | Olfa Trabelsi-Grati | Samia Melaabi | Roseline Vibert | Samantha Antonio | Coralie Franck | Michèle Galut | Isabelle Guillou | Maral Halladjian | Yves Allory | Joanna Cyrta | Julien Romejon | Eleonore Frouin | Dominique Stoppa-Lyonnet | Jennifer Wong | Christophe Le Tourneau | Ivan Bièche | Nicolas Servant | Maud Kamal | Julien Masliah-Planchon

Abstract Background High tumor mutational burden (TMB) was reported to predict the efficacy of immune checkpoint inhibitors (ICIs). Pembrolizumab, an anti-PD-1, received FDA-approval for the treatment of unresectable/metastatic tumors with high TMB as determined by the FoundationOneCDx test. It remains to be determined how TMB can also be calculated using other tests. Results FFPE/frozen tumor samples from various origins were sequenced in the frame of the Institut Curie (IC) Molecular Tumor Board using an in-house next-generation sequencing (NGS) panel. A TMB calculation method was developed at IC (IC algorithm) and compared to the FoundationOne (FO) algorithm. Using IC algorithm, an optimal 10% variant allele frequency (VAF) cut-off was established for TMB evaluation on FFPE samples, compared to 5% on frozen samples. The median TMB score for MSS/POLE WT tumors was 8.8 mut/Mb versus 45 mut/Mb for MSI/POLE-mutated tumors. When focusing on MSS/POLE WT tumor samples, the highest median TMB scores were observed in lymphoma, lung, endometrial, and cervical cancers. After biological manual curation of these cases, 21% of them could be reclassified as MSI/POLE tumors and considered as “true TMB high.” Higher TMB values were obtained using FO algorithm on FFPE samples compared to IC algorithm (40 mut/Mb [10–3927] versus 8.2 mut/Mb [2.5–897], p < 0.001). Conclusions We herein propose a TMB calculation method and a bioinformatics tool that is customizable to different NGS panels and sample types. We were not able to retrieve TMB values from FO algorithm using our own algorithm and NGS panel.

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Directory of Open Access Journals - Sweden

2024

Lukhanin V.A. | Khizhnyak V.I. | Psiukalo S.P. | Gordeeva Y.V. | Yudaev I.V.

The article presents the results of research on the distribution of mineral fertilisers and seeds by centrifugal spreaders on the field surface. A uniform distribution of seeds and mineral fertilisers by centrifugal spreaders depends on a variation of such parameters as mathematical expectation of a throwing angle and its standard deviation. The purpose of the research presented in the article is to check the reliability of the results of calculating the throwing angle of a centrifugal spreader by different methods in the Mathcad programme. The article considers the equation of particle motion on the blade of a centrifugal disc in order to determine the throwing angle of particles after coming off the blade. On the basis of this equation in the Mathcad programme, calculations of the throwing angle of the centrifugal distributor are made in three ways. The first two methods of calculation involve the use of the simplified formula of M.G. Doganovsky and V.V. Ryadnykh, obtained by solving the differential equation of particle motion along the blades of the centrifugal disc by discarding the exponent with a negative exponent. The third method of calculation is performed without simplifications and is taken by us as a reference. The results of comparative analysis of the used methods of calculation are given and the assumption about the violation of symmetry of the sieving sector with the increase in the seeding rate is put forward.

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Directory of Open Access Journals - Sweden

2023

Yasunobu Ando | Takeru Nakashima | Heming Yin | Ikuma Tateishi | Xiaoni Zhang | Yuki Tsujikawa | Masafumi Horio | Nguyen Thanh Cuong | Susumu Okada | Takahiro Kondo | Iwao Matsuda

We have extensively searched for a cyclic hydrogenated boron molecule that has a three-center two-electron bond at the center. Using first-principles calculations, we discovered a stable molecule of 2:4:6:8:-2H-1,5:1,5-&mu:H-B8H10 and propose its existence. This molecule can be regarded as a building block for sheets of topological hydrogen boride (borophane), which was recently theoretically proposed and experimentally discovered. The electronic structure of the cyclic hydrogenated boron molecule is discussed in comparison with that of cyclic hydrogenated carbon molecules.

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Multidisciplinary Digital Publishing Institute - Switzerland

2023

Berska Joanna | Bugajska Jolanta | Sztefko Krystyna

Background: Serum osmolality can be measured (Omeas) or calculated (Ocal). Many formulas for Ocal have been already published, but data regarding the most accurate equation in small babies is not available. Thus, we aim to compare Omeas and Ocal obtained by different formulas in newborns and small children. Methods: The study included 280 serum samples taken from children, from the first day of life to 2 years (mean age 8.2 ± 7.6 months) treated in the University Children's Hospital in Krakow. The serum osmolality was measured by osmometer and calculated by 8 common formulas. Results: The mean value of Omeas (2 8 5 .8 ± 5 .1 mOsm/kgH2O) was significantly different as compared to the mean values of Ocal (p< 0.01) for all formulas, except Ocal obtained by the formula: 1.86*(N a + K) +1.15*Glu + Urea + 14. According to Bland-Altman analysis, this formula showed the best performance for estimating osmolality. In children under 3 months of life Passing-Bablok regression indicated both systematic and proportional error for results obtained by each formula compared to the measured values. Conclusions: To calculate osmolarity in children aged between 3 months and 2 years old the following equation: 1 .86*(N a + K) + 1.1 5*G lu+ U rea+ 14 might be used, whereas serum osmolality in children up to 3 month of life should be measured.

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Directory of Open Access Journals - Sweden

2023

Vinogradova, A.V. | Vinogradov, A.V.

The purpose of the study is to elaborate the methodology for calculating indicators of power supply reliability taking into account seasonality. It was revealed that emergency and planned outages in settlement networks are seasonal in nature by months of the year and time of day, which is associated in the case of emergency with climatic conditions, uneven load schedules, etc. In the case of scheduled outages, seasonality is caused by work schedules during the day, planning of repair programs, etc. Information about the methods for calculating reliable indicators of the reliability of electricity supply to rural consumers is given. Analysis of existing techniques shows no possibility to perform certain calculations of reliability indicators depending on the season of year and time of day. This leads to the impossibility of a differentiated determination of the probability of failure-free operation, the time of interruptions in power supply. Many consumers have a seasonal technological process, the damage from interruptions in power supply is not the same for them, depending on the moment of occurrence of outage, including the scheduled one. The developed methodology makes it possible to calculate the indicators of the reliability of power supply to rural consumers, taking into account the seasonality of interruptions in power supply by month and time of day. It involves the determination of the relevant seasonality coefficients and the adjustment with the help of these coefficients of the average annual reliability indicators of the network in question, which makes it possible to obtain the probability of failure-free operation for emergency and planned outages. Analytical dependencies and equations for determining the corresponding coefficients are given. The network configuration for which it is necessary to perform the calculation, its length is determined. Based on the studied statistical information, the values of the corresponding coefficients will be determined in the future, and the probability of outages at different time points will be compared with possible damage to consumers. | Цель исследований – разработать методику расчёта показателей надёжности электроснабжения с учётом сезонности. Аварийные и плановые отключения в электрических сетях варьируют по месяцам года и времени суток, что связано в случае аварийных отключений с климатическими условиями, неравномерностью графиков нагрузки и др. В случае плановых отключений сезонность вызвана графиками работ в течение суток, планированием ремонтных программ и т.д. Приведены сведения о методиках расчёта показателей надёжности электроснабжения сельских потребителей. Анализ существующих методик показал, что они не позволяют выполнять дифференцированный расчёт показателей надёжности в зависимости от сезона года и времени суток. Это приводит к невозможности дифференцированного определения вероятности безотказной работы, времени перерывов в электроснабжении. Многие потребители имеют сезонный характер технологического процесса, ущерб от перерывов в электроснабжении для них неодинаков в зависимости от момента возникновения отключения, в т. ч. планового. Разработанная методика позволяет выполнять расчёт показателей надёжности электроснабжения сельских потребителей с учётом сезонности перерывов в электроснабжении по месяцам и времени суток. Она предполагает определение соответствующих коэффициентов сезонности и корректировку с их учётом средних годовых показателей надёжности рассматриваемой сети, что позволяет получить вероятность безотказной работы по аварийным и плановым отключениям. Приведены аналитические зависимости и уравнения для определения соответствующих коэффициентов; определяется конфигурация сети, для которой необходимо выполнить расчёт, её протяжённость. На основании изученной статистической информации в дальнейшем будут определяться значения соответствующих коэффициентов, сопоставление вероятности отключений в разные моменты времени с возможными ущербами для потребителей.

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Central Scientific Agricultural Library - Russian Federation

2023

Fedor V. Svoykin | Vladimir F. Svoykin | Viktoriia A. Sokolova | Sergey A. Voinash | Sergey Ye. Ariko

В статье приведены сдерживающие факторы применения традиционных решений для трелевки древесины в зимний лесозаготовительный период в Северо-Западном федеральном округе Российской Федерации. На основе обзора научной литературы дана классификация канатно-рельсовых дорог, рассмотрены способы крепления платформы или вагона к тяговому тросу, особенности выбора троса. Описаны режимы работы канатно-рельсовых дорог (без двигателя – как лесоспуск, с двигателем без замыкающего троса, с двигателем с замыкающим тросом), рассмотрены основные требования к канатно-рельсовым дорогам и факторы, ограничивающие область применения таких дорог. Предложена методика определения движущих сил. Она учитывает вес движущегося по склону вагона, количество вагонов, угол наклона участка пути, сопротивление движению вагона, дополнительное сопротивление движению вагона при прохождении кривых участков, вес троса, его длину, трение троса о землю, шпалы и другие препятствия, которое зависит от состояния верхнего строения пути, густоты укладки шпал, выступающего на поверхность балласта, смазки троса и других факторов. Кроме перечисленного принимались во внимание потери мощности от сопротивления путевых роликов при огибании их сбегающей ветвью троса, потери на трение в цапфах барабанов лебедки и на огибание тросом барабанов лебедки. В статье обсуждаются условия, при которых возможно передвижение вагона вниз по склону, исключаются пробуксовки и обеспечиваются торможения троса в канавках барабанов. Определены ограничения применения канатно-рельсовых дорог в зависимости от характера пути, подвижного состава, угла наклона трассы, среднего расстояния трелевки. Предложено техническое решение по усовершенствованию существующих канатно-рельсовых дорог с использованием шарнирно-сочлененной каретки, повышающей эксплуатационные свойства канатно-рельсовых дорог. Описанная в статье конструкция позволяет снизить износ канатов и организовать заготовку лесоматериала, в том числе на непрямолинейных трелевочных волоках с углами поворота до 45º. При этом конструкция шарнирно-сочлененной каретки может эффективно применяться на уже находящихся в эксплуатации канатно-рельсовых дорогах. Для цитирования: Свойкин Ф.В., Свойкин В.Ф., Соколова В.А., Войнаш С.А., Арико С.Е. Применение канатно-рельсовых дорог для трелевки сортиментов // Изв. вузов. Лесн. журн. 2023. № 5. С. 115–125. https://doi.org/10.37482/0536-1036-2023-5-115-125 | The article presents constraining factors of the use of traditional approaches for timber skidding in the winter logging period in the North-West Federal District of the Russian Federation. Based on the study of scientific literature, the classification of cable-railways is given, methods of fastening the platform or cable car to the traction cable, the peculiarities of cable selection are considered. The modes of operation of cable-railways are described (without an engine – as a timber slide, with an engine without a trailing cable, with an engine with a trailing cable), the basic requirements for cable-railways and factors limiting the scope of application of such roads are considered. A methodology for determining the driving forces is proposed. It takes into account the weight of the car moving on the slope, the number of cars, the angle of inclination of the track section, the resistance to car movement, additional resistance to car movement when passing curves, the weight of the cable, its length, the friction of the cable on the ground, sleepers and other obstacles, which depends on the condition of the track structure, the density of sleeper laying, ballast protruding on the surface, cable lubrication and other factors. In addition to the above, power losses from the resistance of track rollers when they are enveloped by the running down branch of the cable, friction losses in the trunnions of the winch drums and friction losses from the cable enveloping the winch drums were considered. The article discusses the conditions under which it is possible to move the car down the slope, as well as prevent slipping and provide cable braking in the grooves of the drums. Limitations for the use of cable-railways, depending on the nature of the track, rolling stock, slope angle of the track, average skidding distance, are determined. A technical solution to improve the existing cable-railways using an articulated carriage that increases the operational properties of cable-railways, is proposed. The proposed design allows to reduce the wear of cables and to organize timber harvesting, including on nonstraight skidding trails with rotation angles up to 45 degrees. At the same time, the design of the articulated carriage can be effectively applied on cable-railways already in operation. For citation: Svoykin F.V., Svoykin V.F., Sokolova V.A., Voinash S.A., Ariko S.Ye. Application of Cable-Railways for Timber Skidding. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 115–125. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-115-125

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Northern (Arctic) Federal University - Russian Federation

2023

Čakšs, Roberts | Jansone, Baiba

Northern Europe will be one of the locations where the renewable energy from forests could displace fossil fuels as a result of climate change: therefore, it will become more crucial to maintain renewable materials that also collect CO2. By taking tree biomass out of forest stands, we could create more renewable resources to use in practice, but this has certain negative effects on the forest ecology, including nitrogen leaching and vegetation degradation. The goal of the study is to investigate the effects of full biomass removal (FBR) in Norway spruce (Picea abies (L.) H. Karst.) forest stands and how this forest management affects vegetation regeneration, tree stock and carbon storage overall. The aforementioned structures were assessed at various forest ages. The central region of Latvia contains Norway spruce stands with all of the sample sites under study situated on drained peaty mineral soils and weakly aerated gleyic soils. As a result of the long-term evaluation, it was determined that the forest vegetation in FBR was similar to that in the same-age control stand (SAC) and that vegetation can successfully regenerate. The average tree height and DBH is lower in areas where stump removal and understory biomass was not carried out. Statistically significant (p<0.05) long-term influence of stump removal on the average height and diameter of Norway spruce can be identified in all parameters, except, tree height in Myrtillosa mel. forest type. Total biomass removal in long term has almost no significant effect on tree stand and vegetation regeneration.

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Fundamental Library of Latvia University of Life Sciences and Technologies - Latvia

2023

Lubējs, Emīls | Jurgelane-Kaldava, Inguna

The objective of this research was to design an economically efficient logistics management model for fuel retail enterprises to improve their competitiveness. In the current global market situation, fuel retail enterprises face various challenges, such as sharp increase in raw material price, intense market competition, high price sensitivity, low profitability, and significant logistics costs. By combining theoretical and practical insights, an improved logistics management model was designed, which provides significant competitive advantage for fuel retail enterprises. The designed model incorporates and integrates three distinct logistics arrangements, resulting in considerable advantages for fuel retail enterprises. These advantages include a reduction in logistics costs and increased independency from the fluctuating logistics service expenses. To determine the economic efficiency of the designed logistics management model, it was validated by using data obtained from a fuel retail enterprise based in Sweden. Results of the research indicated that the fuel retail enterprise can anticipate an annual reduction in logistics costs ranging from 2.91% to 3.32% from the implementation of the improved logistics management model. On top of that, the developed logistics management model is projected to be economically viable until 2027, assuming the continuation of the current market trends and conditions. The findings of the research suggest that other fuel retail enterprises may also benefit from implementation of the designed model in the current market conditions.

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Fundamental Library of Latvia University of Life Sciences and Technologies - Latvia

2023

Roziņš, Rihards | Brencis, Raitis | Spulle, Uldis | Spulle-Meiere, Ivanda

It is well known that wood tends to shrink and swell as the relative humidity of the air changes. There have been, and still are, attempts to make dimensionally stable wood panels such as Dendrolight. The physical-mechanical, operational, including acoustic, properties of this material have been significantly improved compared to traditional wood-based panels. However, the production of this material requires very specific processing equipment and a large energy investment. The developers of this material in Latvia invented and patented wood, Lightweight Stabilised Blockboard (LSB). In order for this material to be used in the production of various products, it is necessary to clarify its characteristic, technological, as well as operational properties. The study gathers information about the sound absorption properties of various natural and wood materials, characteristics, and the sound absorption of the studied material at different sound frequencies. The reviewed sources of information indicate that nowadays there are still problems in sound conduction and absorption and isolation issues are being addressed in building acoustics. The production of samples and the determination of sound absorption were carried out using a developed methodology developed in accordance with regulatory requirements. The data obtained in the practical study were compared with the relevant indicators of the Dendrolight and wood-based panels used for building structures and to determine their compliance with the requirements set forth in the standards ISO 10534-2 and ISO 11654. Research data show that LSB corresponds to E sound absorption class in some of the investigated frequencies.

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Fundamental Library of Latvia University of Life Sciences and Technologies - Latvia