Growth Rate Values Research Articles

Development of a Xanthan Gum Based Superabsorbent and Water Retaining Composites for Agricultural and Forestry Applications

In this work, bio-based hydrogel composites of xanthan gum and cellulose fibers were developed to be used both as soil conditioners and topsoil covers, to promote plant growth and forest protection. The rheological, morphological, and water absorption properties of produced hydrogels were comprehensively investigated, together with the analysis of the effect of hydrogel addition to the soil. Specifically, the moisture absorption capability of these hydrogels was above 1000%, even after multiple dewatering/rehydration cycles. Moreover, the soil treated with 1.8 wt% of these materials increased the water absorption capacity by approximately 60% and reduced the water evaporation rate, due to the formation of a physical network between the soil, xanthan gum and cellulose fibers. Practical experiments on the growth of herbaceous and tomato plants were also performed, showing that the addition of less than 2 wt% of hydrogels into the soil resulted in higher growth rate values than untreated soil. Furthermore, it has been demonstrated that the use of the produced topsoil covers helped promote plant growth. The exceptional water-regulating properties of the investigated materials could allow for the development of a simple, inexpensive and scalable technology to be extensively applied in forestry and/or agricultural applications, to improve plant resilience and face the challenges related to climate change.

Analysis of high frequency Alfvén eigenmodes observed in ASDEX Upgrade plasmas in the presence of RF-accelerated NBI ions

High frequency Alfvén eigenmodes in the ion cyclotron frequency range are actively researched on the ASDEX Upgrade tokamak (AUG). The general properties of this particular mode type are: (a) the mode is beam-driven and, if excited, can persist for the entire duration of the beam-on time window; (b) the mode is sub-cyclotron with the frequency ω ∼0.5ω ci, where ωci corresponds to the on-axis cyclotron frequency of the beam ions; (c) the mode propagates in the counter-current/counter-injection direction; and (d) the field-aligned (∼toroidal) mode number is large: |n //| ∼50. It has been observed on AUG that radio frequency- (RF)-acceleration of beam-injected ions at the 3rd cyclotron harmonic significantly expands the number of excited modes. In this work we demonstrate how this observation is consistent with the global Alfvén eigenmode (GAE) behavior. The RF-driven fast ion population is modeled using a combination of an orbit-following Monte Carlo code (ASCOT-RFOF) and an electro-magnetic wave code (TORIC). The application of this code combination is a first to model beam-ion RF-acceleration at the 3rd cyclotron harmonic. The RF-accelerated fast ion distributions are then used to analytically calculate anisotropy-driven mode growth rates. We see that the region of positive (unstable) growth rates is expanded by RF-accelerated fast ions in both the frequency and the mode number directions for the GAEs, consistent with the measurements. Although the compressional Alfvén eigenmode growth rates are also positive for our particular fast ion distributions, the growth rate values are ∼3 orders of magnitude lower. The plasma conditions on AUG are more destabilizing to the GAEs. Overall, our results are consistent with the observation of similar modes on other conventional tokamaks, namely JT-60U and DIII-D.

Response of Nile tilapia under biofloc system to floating or sinking feed and feeding rates: Water quality, plankton community, growth, intestinal enzymes, serum biochemical and antioxidant status

The current study examined the combined effects of feeding rates and feeding types on the water quality, growth performance, digestive enzymes, blood parameters, and liver antioxidant enzymes of Nile tilapia (Oreochromis niloticus) fingerlings reared under a biofloc system. A 3 × 2 factorial experimental design was used with three feeding rates (2%, 3%, and 4%) and two feeding types (sinking or floating feed), comprising six treatments with three replicates. Fingerlings with an initial body weight of 4.50 ± 0.25 g were stocked in eighteen circular plastic tanks (0.5 m3) at a stocking density of 35 fish per tank fed three times a day at 10:00, 12:00 and 15:00. Starch was added to all treatments as an organic carbon source at a C/N ratio of 10:1. The phytoplankton community was determined to consist of twenty-two species, including individuals from the classes Cyanobacteria, Chlorophyceae, and Bacillariophyta. The most common phytoplankton classes were Chlorophyceae, followed by Cyanobacteria, and fish-fed floating feed at a feeding rate of 2% of total biomass yielded the greatest number of phytoplankton communities. Eight zooplankton species belonging to rotifers and protozoa were identified during this experiment. The highest values of final body weight, weight gain, and specific growth rate were recorded for a fish-fed floating diet with the highest feeding rate (4% of biomass). The highest hepatosomatic index (HIS) was detected in a fish-fed floating diet at a rate of 4% of total biomass. Though fish-fed sinking feed with a 4% biomass feeding rate presented the highest spleen index (SI). The highest significant (P < 0.05) level of amylase was found in fish-fed sinking feed at a 4% feeding rate. While lipase activity was higher (P < 0.05) in the group fed floating feed at a feeding rate of 3% of total biomass. Feeding rates, feed types, and their interactions had no appreciable effect (P > 0.05) on hemoglobin (Hb), hematocrit (Hct), and red blood cells (RBCs). Feeding rate, feed type, and their interactions had no significant impact (P > 0.05) on serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), or albumin, but feeding rates or feed types had an effect (P < 0.05) on total protein and globulin (P < 0.05). The highest levels of growth hormone (GH) (P < 0.05) were found in fish-fed either sinking feed at a feeding rate of 2% or floated feed at a feeding rate of 3% of total biomass. The fish group fed floating or sinking feed at a feeding rate of 2%, floating feed at 3%, and sinking feed at 4% recorded the highest high-density lipoprotein (HDL-C) values with an insignificant difference. Considering the liver's antioxidant enzymes, the highest catalase (CAT) and glutathione (GSH) levels were shown in fish that received either sinking or floating feed at feeding rates of 2% and 3%, respectively. Whereas, the lowest melanodialdehyde (MDA) was found in fish-fed sinking feed at a feeding rate of 3% of total biomass. According to the study's findings, the biofloc system significantly improved both the water quality and the efficiency of Nile tilapia. In addition, feeding tilapia 4% floating feed resulted in maximum feed consumption with minimal waste, improved nutritional efficiency and feed conversion efficiency, lowered production costs, and lessened water pollution.

Dynamic hybrid modeling of fuel ethanol fermentation process by integrating biomass concentration XGBoost model and kinetic parameter artificial neural network model into mechanism model

Fuel ethanol has drawn extensive attention as renewable energy. However, modeling the fuel ethanol batch fermentation process is still a critical task. The unstructured kinetic model (UKM) is often utilized to model the process, but it encounters two problems due to the large differences in initial glucose concentrations. First, the UKM has poor predictions of the yeast growth, which is a crucial production index. Second, the kinetic parameters of the UKM are time-varying because of the changing environmental conditions. The constant manually set kinetic parameters affect the prediction accuracy. To tackle the problems, we propose a dynamic hybrid model of the fuel ethanol fermentation process. First, a biomass concentration prediction model based on extreme gradient boosting is developed. It predicts the values of biomass concentrations and mycelium growth rate as supplementary mechanism knowledge. Then, we present an artificial neural network-based model to determine the time-varying kinetic parameters. Our model can accurately predict the time series of biomass, ethanol, and glucose concentrations, with RMSEs reaching 0.3323, 1.9295, and 3.0540. Experimental results show that the dynamic hybrid model performs with satisfactory accuracy in modeling the fuel ethanol fermentation process.

Salinized water as a strategy for increase stocking density in Heros severus larviculture, an Amazonian ornamental fish

The aim of this study was to evaluate the effect of different salinized water (0, 3 and 6 g L-1) and stocking densities (10, 15 and 20 larvae L-1) in Heros severus larviculture. The experimental design was completely randomized, in a 3x3 factorial design, with three replicates. For this, a total of 405 larvae of H. severus were randomly distributed in 27 aquariums (1L) according to the treatments and after 15 days all the larvae were measured, weighed and counted. Higher values for final length, length gain and specific growth rate were observed in H. severus larvae raised at any stocking density tested at 3 g L-1 of salinized water (p &lt; 0.05). The final weight and weight gain followed the same trend of the length, being higher in fish submitted to 3 g L-1 of salinized water (p &lt; 0.05). On the other hand, the salinized water of 6 g L-1 was detrimental to larvae weight uniformity and survival rate (p &lt; 0.05). The fish stocked at densities of 15 or 20 larvae L-1 presented the best results of final weight and weight gain (p &lt; 0.05). The stocking density of 20 larvae L-1 in salinized water at 3 g L-1 is recommended for H. severus larviculture.

Intrinsic thermo-acoustic instability criteria based on frequency response of flame transfer function

The study of Intrinsic Thermo-Acoustic (ITA) instability behavior of flames anchored to a burner deck is performed by introducing a mapping between the Flame Transfer Function, FTF(s), defined in the complex (Laplace) domain and experimentally measured frequency response, FTF(iω). The conventional approach requires a system identification procedure to obtain the FTF(s) from the FTF(iω); next, root-finding techniques are applied to define the complex eigenfrequencies. The purpose of the present work is to establish instability criteria which are directly applicable in the frequency domain. The particular case is considered when the acoustic boundary conditions at both sides of the flame are anechoic. At first place, the causality of the measured FTF(iω) is checked. Then, the criteria of the ITA mode instability applicable to the FTF(iω) phase and magnitude, are derived. Cauchy's theorem and the path-independence Lemma are used to find the scaling factor of the mapping which allows to determine bounds of the unstable frequency and the maximum value of the linear growth rate. The proposed method is applied to study the behavior of burners with premixed burner-stabilized Bunsen-type flames. The comparison of the measured oscillation frequencies and the growth rates of observed unstable oscillations with that obtained from the derived bounds reveal good correspondence.

Investigating the Health of a Rice Field Ecosystem Using Thermodynamic Extremal Principles

This study investigates the dynamic behaviour of a rice field ecosystem and aims to define its integral features using the stability concept of an ecological goal function. This function is based on the extremal principles of thermodynamics, which assume that certain energetic processes of ecosystems—such as the rate of exergy destruction—are directed by the self-organizing informatics of the systems towards maxima or minima. In our study, we exploit the availability of substantially long time-series data relating to a rice field ecosystem to gain an evocative understanding of its growth trajectory in light of the thermodynamic principles. We accomplished this by constructing a model based on the STELLA 9.0 software and calculating the extremal values of growth rates (storage) and those of exergy destruction and entropy creation. The results showed that the values of both maximum dissipation and maximum exergy progressed apace with that of maximum storage till the maturation of rice and became stable thereafter, whereas maximum residence time and maximum specific dissipation values initially decreased before their asymptotic rise. A similar pattern was also observed for the maximum specific exergy. However, the maximum power dissipation curve followed a highly fluctuated course before becoming stable on the maturation of rice.

Effects of chlorine and peroxyacetic acid wash treatments on growth kinetics of Salmonella in fresh-cut lettuce

Fresh-cut produces are often consumed uncooked, thus proper sanitation is essential for preventing cross contamination. The reduction and subsequent growth of Salmonella enterica sv Thompson were studied in pre-cut iceberg lettuce washed with simulated wash water (SWW), sodium hypochlorite (SH, free chlorine 25 mg/L), and peroxyacetic acid (PAA, 80 mg/L) and stored for 9 days under modified atmosphere at 9, 13, and 18 °C. Differences in reduction between SH and PAA were non-existent. Overall, visual quality, dehydration, leaf edge and superficial browning and aroma during storage at 9 °C were similar among treatments, but negative effects increased with temperature. These results demonstrated that PAA can be used as an effective alternative to chlorine for the disinfection of Salmonella spp. in fresh-cut lettuce. The growth of Salmonella enterica sv Thompson was successfully described with the Baranyi and Roberts growth model in the studied storage temperature range, and after treatment with SWW, chlorine, and PAA. Subsequently, predictive secondary models were used to describe the relationship between growth rates and temperature based on the models’ family described by Bělehrádek. Interestingly, the exposure to disinfectants biased growth kinetics of Salmonella during storage. Below 12 °C, growth rates in lettuce treated with disinfectant (0.010–0.011 log CFU/h at 9 °C) were lower than those in lettuce washed with water (0.016 log CFU/h at 9 °C); whereas at higher temperatures, the effect was the opposite. Thus, in this case, the growth rate values registered at 18 °C for lettuce treated with disinfectant were 0.048–0.054 log CFU/h compared to a value of 0.038 log CFU/h for lettuce treated with only water. The data and models developed in this study will be crucial to describing the wash-related dynamics of Salmonella in a risk assessment framework applied to fresh-cut produce, providing more complete and accurate risk estimates.

Effects of thermal fluctuation when an optical cavity possesses neutral atoms and a two-mode laser system

Quantum-based experiments and their applications in lasers and magnetic fields have long been paramount, yet how to achieve exact stability for a long time is a merely answered question. This article develops a coupled laser map with cavity loss via a one-dimensional laser map, where complex phenomena in the newly developed mathematical model, dynamical properties with coupling delay, and thermal fluctuation of the lasing system are discussed numerically and analytically. It is deduced that the intensity of the laser beam can be controlled and stabilized for a long time, and large values of the effective gain coefficient can be reached when thermal noise exists in the optical cavity and when a nonlinear feedback loop is provided with coupling delay. Utilizing noise and coupling delay as a nonlinear feedback loop to the coupled laser map, we observed non-autonomous behaviour at different growth rate values. In contrast, symmetrical and phase-entrained synchronized mirror imaged orthogonal strange attractors and fractals were seen at the same growth rate values. At specific values of the controlling parameters, the peculiar attractors experience cyclic collisions with their basin boundaries, which break symmetry and synchronization and cause irregular behaviour.

Photoprotective and antigenotoxic properties of Cutibacterium acnes ecotypes native to terrestrial subsurface habitats.

Actinobacteria are known to produce a variety of secondary metabolites with skin-protective properties. This study aimed to investigate the photoprotective and antigenotoxic properties against UVB of extracts obtained from Cutibacterium acnes strains. Bacterial growth was measured spectrophotometrically and the constant maximum growth rate (μ) value to each strain, were calculated. In vitro photoprotection efficacy was evaluated using in vitro indices such as sun protection factor (SPFespectrophotometric) and critical wavelength (λc). UVB-antigenotoxicity was also evaluated using the SOS Chromotest. Correlation analysis was used to examine the relationship between SPFespectrophotometric and extract concentration and the %GI estimates. Among the studied strains, one showed low (6.0≤SPFespectrophotometric≤14.9) and eight showed media (15.0≤SPFespectrophotometric≤29.9) UVB photoprotection efficacy. All of them resulted in broad-spectrum (UVA-UVB) photoprotection (λc > 370nm). In total, two C. acnes ecotypes with different growth rates were evidenced, but the protective metabolites in the extracts were produced without the influence of growth rate. Photoprotective efficacy depended on the extract concentration and was correlated with antigenotoxicity. We demonstrated that C. acnes extracts can be used as sunscreen ingredients that reduce UVB-induced genotoxicity.

Growth indices, photosynthetic parameters and productivity of barley (Hordeum vulgare) as influenced by sowing dates and cutting management

A field experiment was conducted during the winter (rabi) seasons of 2015–16 and 2016–17 at the Punjab Agricultural University, Ludhiana, to study the effect of staggered sowing on growth indices, photosynthetic parameters and productivity of barley (Hordeum vulgare L.) in relation to different cutting management. The experiment was laid out in a split-plot design with 3 sowing dates, viz. 15 October, 30 October and 15 November in main plots and 5 cutting management, viz. un-cut (control), cut at 50 days after sowing (DAS), cut at 60 DAS, cut at 50 DAS + additional 15 kg N/ha after cut (N15) and cut at 60 DAS + additional 15 kg N/ha after cut (N15)] in subplots, replicated 4 times. The results indicated that, the crop sown on 15 October registered the highest values of absolute growth rate (AGR) and crop growth rate (CGR) up to 120 days of crop-growth. Thereafter, crop sown on 15 November showed higher AGR and CGR values than that sown on 15 October and 30 October. Relative growth rate (RGR) was the highest in the crop sown on 15 October up to 30 days; 30 October up to 120 days and 15 November thereafter. Fodder cut at 50 DAS and cut at 50 DAS + N15 treatments resulted in the negative values of AGR, CGR and RGR during 30–60 DAS. Transpiration rate and stomatal conductance decreased significantly and progressively with each delay in sowing. Uncut crop recorded the highest transpiration rate (0.53 m mol/m2/sec), whereas the crop cut at 60 DAS resulted in the lowest transpiration rate (0.26 m mol/m2 /sec). Crop sown on 15 October resulted in 11.9 and 47.9% more grain yield and 18.3 and 25.2% more fodder yield than that sown on 30 October and 15 November, respectively. Control and cutting for fodder at 50 DAS gave similar grain yields, but were significantly higher than the other cutting-management treatments.

Unraveling signatures of chicken genetic diversity and divergent selection in breed-specific patterns of early myogenesis, nitric oxide metabolism and post-hatch growth.

Introduction: Due to long-term domestication, breeding and divergent selection, a vast genetic diversity in poultry currently exists, with various breeds being characterized by unique phenotypic and genetic features. Assuming that differences between chicken breeds divergently selected for economically and culturally important traits manifest as early as possible in development and growth stages, we aimed to explore breed-specific patterns and interrelations of embryo myogenesis, nitric oxide (NO) metabolism and post-hatch growth rate (GR). Methods: These characteristics were explored in eight breeds of different utility types (meat-type, dual purpose, egg-type, game, and fancy) by incubating 70 fertile eggs per breed. To screen the differential expression of seven key myogenesis associated genes (MSTN, GHR, MEF2C, MYOD1, MYOG, MYH1, and MYF5), quantitative real-time PCR was used. Results: We found that myogenesis associated genes expressed in the breast and thigh muscles in a coordinated manner showing breed specificity as a genetic diversity signature among the breeds studied. Notably, coordinated ("accord") expression patterns of MSTN, GHR, and MEFC2 were observed both in the breast and thigh muscles. Also, associated expression vectors were identified for MYOG and MYOD1 in the breast muscles and for MYOG and MYF5 genes in the thigh muscles. Indices of NO oxidation and post-hatch growth were generally concordant with utility types of breeds, with meat-types breeds demonstrating higher NO oxidation levels and greater GR values as compared to egg-type, dual purpose, game and fancy breeds. Discussion: The results of this study suggest that differences in early myogenesis, NO metabolism and post-hatch growth are breed-specific; they appropriately reflect genetic diversity and accurately capture the evolutionary history of divergently selected chicken breeds.

Unstructured kinetic models with time-averaged growth approach in the biodegradation of triclosan by activated sludge culture

The concentration of triclosan in wastewater is expected to rise dramatically as a consequence of the COVID-19 pandemic. A modeling analysis of the growth kinetics of microbial culture during triclosan degradation was necessary in order to establish effective wastewater treatment. The kinetic parameters are used by engineers to aid in the design and process control of biological processes. Studies were conducted using triclosan-acclimated culture to examine biomass growth and associated substrate degradation at different initial substrate concentrations (0.35–4.9 mg L−1) to this end. Substrate inhibition was calculated from experimental growth parameters using unstructured kinetic models. Unlike other model studies, a time-averaged specific bacterial growth rate in the log phase was considered for kinetic models in this study. Overestimation of the conventional log phase calculation for unstructured kinetic model constants was eliminated when the slowdown growth part of the log growth phase was taken into account. The Haldane Model was more accurate to fitting experimental data in an excellent manner. In this case, the time-averaged specific growth rate, saturation constant, and inhibition constant were 0.56 h−1, 12.77 mg L−1, 0.52 mg L−1, respectively. A yield coefficient of 0.404 mgX.mgS−1 was calculated. The critical triclosan concentration was 2.57 mg L−1. Wastewater treatment plants can be more sensitive to the value of the critical triclosan concentration. The value for time-averaged critical specific growth rate was 0.051 h−1. Pre-or post-treatment requirements can be estimated using time-averaged critical growth rate values as a benchmarking tool in biological treatment systems.

Экологиялық тізбектер және олардың математикалық-компьютерлік моделдері

The article deals with the problem of studying the structures and evolutions of ecological chains at the level of microorganisms using mathematical and computer models. Several mathematical models have been constructed based on the laws of biological kinetics. Computer experiments were developed using these models. Mathematical models describing the dependence of the concentration of bacterial biomass, substrates and protozoa on time have been created. With the help of the Mathcad package, graphical solutions of mathematical models were obtained and analyzed. Graphs of the states of ecological chains with changes in the rate of penetration of the nutrient substrate into the system were created and these states were studied. Mathematical models describing the mutual competition of 6 different bacteria were developed in Mathcad environment. The parameters characterizing the biomass concentration of each bacterium were established. This parameter included: saturation constant of bacteria, saturation constant of protozoa, maximum value of specific growth rate of bacteria, maximum value of specific growth rate of protozoa, and economic growth coefficient of protozoa. Graphical solution of mathematical models have been analyzed. These models characterize the dynamics of the concentration of bacterial biomass. A computer experiment representing competition between bacterial species was developed. The results of mutual competition of ten different bacterial colonies were obtained on the basis of numerical and graphical methods. The software has been compiled in Microsoft Visual Basic 6.0 environment.

Stability analysis of a targeted chemotherapy-cancer model

&lt;abstract&gt;&lt;p&gt;This study addresses a modified mathematical model of tumor growth with targeted chemotherapy consisting of effector cells, tumor cells, and normal cells. To investigate the dynamics of the model, local and global stability analyses have been performed at the equilibrium points of the model. It is found that the tumor-free steady state is globally asymptotically stable under certain conditions, which suggests that the prescribed treatment can eradicate tumor cells from the body for a threshold value of tumor growth rate. The main result of this study is that if the tumor growth rate is tiny, it is possible to eradicate the tumor from the body using a smaller amount of targeted chemotherapy drugs with less harm to the other healthy cells. If not, it requires a high dose of targeted chemotherapy drugs, which can increase the side effects of the drugs. Numerical simulations have been performed to verify our analytical results.&lt;/p&gt;&lt;/abstract&gt;

Стресс реальных доходов в российских регионах в условиях пандемии и санкций

The study is devoted to assessing the stress of real incomes of the population (regarding wages) and the real financial result of enterprises in the Russian regions during the pandemic and sanctions shocks of 2017–2023. We used a number of methods of deflation, elimination of seasonal and random components in the dynamics of indicators. To assess the stress level, a stress index, developed by the author earlier, which is a moving (with a one-month step) difference between the standard deviation and the average value of the annual growth rate of each indicator under study, as well as a way to decompose it by source, was used. Integral real income stress index was calculated as the sum of two particular stress indices normalized by the method of equivalent variances on the scale of the entire spatiotemporal sample. As a result of the study, similarities and differences in the reaction of real incomes of the population in regions and federal districts under the impact of pre-pandemic, pandemic and new sanctions shocks were revealed, as well as different reactions of wages and financial results of the enterprises in them, certain spatial effects, areas of stability and increased risk. It has been established that the reduction of the level of real income stress across the country occurs due to the greater stability of the growth rates of the indicators under consideration in regions with high incomes, while the positive influence of the effect of interregional diversification has not received empirical confirmation

НЕКОТОРЫЕ ДЕМОГРАФИЧЕСКИЕ ПОКАЗАТЕЛИ РОССИИ В 2000-2021 ГОДЫ

Significance. Fertility and mortality analysis helps identify major demographic risk zones. Recently, due to intensive development of digitalization in Russia, a lot of statistical information has become publicly available. Its generalization and analysis are necessary for developing social programs aimed at copying with the identified risk factors and improving the demographic situation. Analysis of the number of women of active reproductive age, total fertility rate, life expectancy, and gender-specific mortality rates are important steps in this direction. Significance of the topic is emphasized by the development and implementation of the national project "Demography" in the Russian Federation in 2019-2024. The purpose of the study was to implement a comparative and dynamic analysis of demographic indicators in Russia to identify risk zones and take effective measures to improve the situation. Material and methods. The analysis uses WHO data, databases and collections of Rosstat and the Ministry of Health of the Russian Federation, information on implementing the national project "Demography". A database has been developed in the licensed statistical package IBM SPSS Statistics-19. A comparative analysis of independent groups of indicators has been undertaken using the Mann-Whitney U-test, related groups – using the Wilcoxon test; while the trend in indicators was determined by Kendall’s Tau coefficient of correlation, graphical analysis was carried out in MS Excel-2013. Results. The determined trends in dynamics show that the pre and post-working age population is naturally increasing, that is, according to these indicators, the goals of the national project are being achieved. The number of women of reproductive age during the study period shows a decreasing trend, which was undoubtedly influenced by the “Russian cross” of the 90s of the last century, when fertility decreased and mortality increased almost twice compared to the end of the 80s. Negative values of the natural growth rate indicate that fertility is lower than mortality during those years. From 2000 to 2015, the trend was positive, the natural growth rate increased while since 2015 the trend was decreasing. The total fertility rate has been declining since 2015. In reality, in 2015, less than 18 children were born to 10 women in Russia, in 2021 – only 15 children, which is below the population replacement level. Conclusion. One of the promising directions for improving the situation is to adopt effective social measures to increase fertility in young women, to increase the total fertility rate, as well as to develop a promising industrial production and incentive programs to prevent the outflow of young population.

A Comparative Study of a:SiCN:H Thin Films Fabricated with Acetylene and Methane

In this paper we present a comparative study of the properties of amorphous hydrogenated silicon carbonitride (SiCN:H) thin films deposited by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD). The elemental composition, growth rate, density, and refractive index values of the SiCN:H thin films were analyzed as functions of flow rates of pure acetylene (C2H2) and methane (CH4) hydrocarbon precursors. The mechanical properties were studied with nanoindentation measurements to compare hardness and Young’s modulus of the SiCN:H thin films deposited with different carbon sources. Variable angle spectroscopic ellipsometry (VASE), elastic recoil detection (ERD), and Rutherford backscattering spectrometry (RBS) were used to determine thin film properties. Higher carbon content in the thin films was achieved by acetylene compared to methane at the same flow rate due to its lower ionization energy during the deposition. Infrared (IR) absorption spectra of the thin films deposited with acetylene precursor were analyzed to determine the correlation between the hydrocarbon flow rate and the intra-molecular bond intensities in the thin films. We found that the major contribution to the hardness comes from hydrogen (H) in the SiCN matrix which makes the films less dense. Carbon improves the hardness, however, H introduced by the hydrocarbon reduces the mechanical strength.

Technological Quality of Potato Tubers: Effect of Potassium Fertilization and Application Time

The effect of potassium fertilization and time of application on yield and tuber quality of potato (Solanum tuberosum L., cv. Agria) was studied in Bekaa region in Lebanon. Potassium was applied in one split at tuber initiation (T1) and at tuber bulking (T2) in four different rates: K0 (0 kg/ha), K1 (100 kg/ha), K2 (200 kg/ha) and K3 (300 kg/ha). Results showed that aerial dry matter decreased and tuber dry matter increased during the growing period. The dry matter accumulation was dependent on potassium fertilization. Potassium concentration gradually decreased in leaves and increased in tubers during the growing period, while the most potassium treatment (K3) has accumulated at harvest, higher potassium concentrations in leaves and tubers, with more emphasis to application time T2 with respect to T1. Moreover, potassium has accelerated significantly (p&lt;0.05) tuber dry matter accumulation. This was revealed by growth rate and harvest index values that were significantly higher (p&lt;0.05) in K3 treatment with comparison to other treatments. Results also showed that fresh tuber yields increased with potassium fertilization and were more pronounced with T2 application whereas K3 had significantly (p&lt;0.05) the highest value of 62.9 t/ha (K3). Yield augmentation was primarily due to an increase in tuber size in the larger (&gt; 60 mm) and the medium (35 – 60 mm) grades. In addition, results showed that tuber dry matter content and specific gravity were statistically dependent on potassium fertilization and application time (p&lt;0.05). The highest potassium treatment K3, regardless of application time, gave the best tuber quality of industrial potato by having the highest dry matter and the lowest reducing sugar contents. Finally, the results of this study suggest that maximum potato yield was obtained with K3 treatment (300 kg/ ha) applied during tuber bulking stage (T2).

Growth of Eucheuma cottonii seaweed from tissue culture with different time acclimatization in Hurun Bay

Constraints on the seaweed culture in Indonesia until now still rely on seeds obtained by vegetative propagation and have poor quality, which often causes a decrease in genetic variability. Planting seaweed seedlings from tissue cultures that have been acclimatized in a greenhouse laboratory is believed to improve the quality of the seaweed seeds. This research aimed to observe the growth of tissue culture acclimatized Eucheuma cottonii seaweed seedlings to different rearing times in greenhouses applied to floating raft cages. This study used a completely randomized design (CRD) with three treatments and three replications. Acclimatization treatment was conducted for 2 weeks, 4 weeks, and 6 weeks. Seaweed seedlings acclimatized in the greenhouse are reared on bamboo floating rafts in the sea, with an initial weight of 5 grams each. The length of maintenance at sea is 28 days. The resulting daily growth rate in two-week acclimatization was 2.92%, the four-week treatment was 2.93%, and the six-week treatment was 2.57%. in raising seedlings at sea, the highest daily growth rate value was in the four-week treatment of 7.25%, followed by the two-week treatment of 7.11% and the six-week treatment of 6.43%.