Gain Values Research Articles

IMPLEMENTATION OF THE MISSOURI MATHEMATICS PROJECT (MMP) LEARNING MODEL ON STUDENT COGNITIVE LEARNING OUTCOMES

This research was motivated by students' low mathematics learning outcomes as evidenced by the average learning outcome score being 4.1 out of a KKM score of 7.0. After observing, one of the problems faced is the lack of student involvement in the learning process. The solution to overcome this problem is the use of a learning model. This research aims to determine how implementing the Missouri Mathematics Project (MMP) learning model affects fourth-grade students' cognitive learning outcomes in fraction material. The method used in this research is a quantitative Pre-Experimental approach, a group post-test design. The subjects in this research were 27 fourth-grade students at Second Sidaraja State Elementary School. At the pretest stage, students' cognitive learning outcomes obtained an average score of 40.18; at the post-test stage, the average value obtained was 83.70. These results obtained a gain value of 0.74 with an increase of 43.52, which is included in the high category. Based on the results of the research and analysis that has been carried out, the Missouri Mathematics Project (MMP) learning model can improve students' cognitive learning outcomes. Implementing this learning model is hoped to help students hone their understanding and abilities to use various practice questions.

DEVELOPMENT MIND MAP LEARNING MEDIA FOR APPLICATION-ASSISTED ENGLISH COURSES

In classroom learning activities, the presence of media is essential to pay attention to. If selected and used according to class conditions, various alternative uses of learning media will provide optimal results. This research aims to develop learning media using the Freemind application in English courses to produce learning media that is valid, practical, and has potential effects. The results obtained from the development stages carried out by researchers showed that the mind map media with the developed Freemind application was declared to have proven its practicality. The score of learning outcomes for English courses in the medium category determined the effectiveness of the mind map media with the Freemind application. This was based on The results of calculating the N gain value in material 1, which was 0.4708 (effective in the medium category), and the calculation of N gain was 0.4882 in material 2 (effective in the medium category), so the average score was 0.4795. However, the basic comparisons used as research material in this study were only obtained from 2 materials.

Pengaruh Pembelajaran Kooperatif TGT dengan Metode GASING Terhadap Pemahaman Konsep Matematis Perkalian Dua Angka di SD

This research aims to determine the influence of TGT type cooperative learning using the GASING method on students' understanding of the mathematical concept of multiplying two numbers. This research uses quantitative research methods with a quasi-experimental research type and a Nonequivalent Control Group Design research design. The population taken was all elementary schools in South Sumedang District, with the research sample being class IV students at SDN Sukaraja I, totaling 60 students. The research instrument is a test in the form of essay questions regarding understanding the mathematical concept of multiplying two numbers. The validity of the instrument is carried out through expert judgment on several experts and testing the instrument on students who then carry out validity and reliability tests. The data were analyzed by comparing the gain values of the control and experimental classes which had been carried out by normality tests, homogeneity tests and research hypothesis tests. The results of this research show that TGT cooperative learning using the GASING method has an influence on understanding the mathematical concept of multiplying two numbers as evidenced by an increase of 0.56 in the experimental class, higher than the increase in the control class of 0.26.

Dual band circularly polarized partially reflecting surface-loaded dielectric resonator-based MIMO antenna for mm-wave 5G applications

Abstract A two-port ceramic-based antenna loaded with partially reflecting surface (PRS) is structured and explored. Fan-shaped slot is utilized to create circularly polarized wave in both frequency ranges. Dual frequency ranges are due to hybrid mode creation inside the ceramic material, i.e. HEM11δ and HEM12δ modes. PRS is used to change the phase gradient, which in turn tilts the radiation beam (±35°) obtained from different port in opposite direction. This concept is useful to reduce the envelop correlation coefficient using far-field. Experimental verification confirms that the designed antenna works from 26.1 to 27.5 GHz and 31.7 to 33.6 GHz along with less than 3-dB axial ratio from 26.5 to 27.1 GHz and 31.9 to 33.1 GHz respectively. Orthogonal placement of ports introduces the concept of polarization diversity and decreases the coupling between ports by an amount of −25 dB. Good gain value (up to 7.0 dBi) and better value of diversity performance make the designed radiator applicable for 5 G millimeter-wave uses.

Dietary tributyrin supplementation promotes the growth by improving intestinal digestive and antioxidant capacity and the abundance of intestinal beneficial bacteria for swimming crab (Portunus trituberculatus)

This study aimed to evaluate the effects of tributyrin (TB) supplementation on the growth, digestive enzyme activity, lipid metabolism, and intestinal health of swimming crab (Portunus trituberculatus) with an initial weight of 12.50 ± 0.02 g. Six experimental diets were formulated, which containing 0%, 0.025%, 0.05%, 0.10%, 0.20%, and 0.40% of TB, respectively. Results showed that crabs fed the diet containing 0.10% TB had significantly higher values of percent weight gain (PWG) and specific growth rate (SGR) than those in other treatments. Crabs fed the diet without TB supplementation showed dramatically higher contents of T-CHO, TG, and MDA in serum than those in other treatments, opposite patterns were recorded for the activities of T-SOD, PPO, NO, ACP, and AKP. The activities of antioxidant enzyme including T-AOC, T-SOD, ACP, AKP and GSH-Px in hepatopancreas were significantly affected by dietary TB levels. Meanwhile, crabs fed the diet without TB supplementation had significantly lower activities of trypsin, lipase, and amylase in the intestine than those in other treatments. The relative expression levels of genes related to antioxidant capacity in the hepatopancreas and intestine were markedly decreased when crabs fed the diet without TB supplementation; however, crabs fed the diet without TB supplementation exhibited the highest expression of genes linked to inflammation among treatments, and the expression levels of crustin and lyso in the intestine were significantly affected by dietary TB levels. The expression levels of genes related to energy metabolism and intestinal immune barrier in the intestine were also influenced by dietary TB levels. Dietary TB supplementation could reduce lipid accumulation in hepatopancreas by upregulating lipid catabolism related genes expression levels and decreasing lipid anabolism related gene expression levels. Muscularis thickness, fold width, and fold height in the intestine were significantly increased with dietary TB increasing from 0% to 0.10%; moreover, lipid droplets, the diameter of R cells and the area of R cells in the hepatopancreas significantly decreased with an increase of dietary TB levels. Additionally, the number of Actinobacteria and Bacteroides significantly increased with an increase of dietary TB levels. To sum up, the TB requirement of swimming crab was 0.089% based on two slope broken-line analysis of PWG. The findings of the current study indicate that TB is an effective growth promoter that can serve as a nutritional supplement to improve the growth performance, promote health and regulate lipid metabolism of swimming crab.

Genotyping KIF1C (c.608G>A) Mutant Reveals a Wide Distribution of Progressive Ataxia in German Charolais Cattle

Bovine progressive ataxia in Charolais cattle was first described in the 1970s; then, cases were reported in Charolais worldwide. A homozygous loss-of-function mutation within the KIF1C gene (c.608G>A) was found to be responsible for this neurodegenerative disease. The aim of this study was to determine whether the mutated KIF1C allele segregates in the German Charolais population and whether the estimated breeding values for growth and muscle conformation are associated with the mutated genotypes. Genetic test results of the KIF1C:c.608G>A variant were available for 1315 Charolais cattle from 35 herds located in Germany. In addition, 324 samples from eight other beef cattle breeds were tested for the mutated KIF1C allele. We were able to demonstrate that the KIF1C mutation is common, with a frequency of 11.75% in the German Charolais population. All but two of the eight (2/8 = 25%) homozygous mutated individuals showed clinical signs consistent with progressive ataxia. The estimated breeding values of muscle conformation in 200- and 365-day-old animals indicated a significant superiority for homozygous mutated animals when compared either with heterozygous or homozygous wild-type genotypes; this was also the case for heterozygous genotypes in comparison with homozygous wild-type genotypes. For the estimated breeding values of daily weight gain in 200- and 365-day-old animals, the significant differences between homozygous mutated and heterozygous or wild-type genotypes were in favour of the homozygous mutant animals. There were no differences in the estimated maternal breeding values among all three KIF1C genotypes. For the first time, two German Angus cattle carrying the KIF1C mutation heterozygous were detected. The breeders’ survey highlighted that increased awareness would facilitate increased conviction among breeders of the need for genetic testing in order to eliminate the lethal KIF1C allele.

Effects of Choline Supplementation in Diets on Juvenile Pacu (Piaractus mesopotamicus): Productive Performance, Proximate Composition and Serum Lipid Level.

Pacu (Piaractus mesopotamicus) is a Brazilian fish species of high commercial value and has emerged as one of the main species with potential for intensive farming. This study aimed to investigate the impact of choline supplementation on productive performance, visceral fat, hepatosomatic indices, proximate composition, serum biochemical profile, and liver coloration in juvenile pacu (Piaractus mesopotamicus). The 60-day experiment was conducted in the experimental hatchery of the Study Group of Aquaculture Management - GEMAq of the State University of West Paraná, Brazil. The completely randomized design consisted of five treatments with four replicates each. A total of 200 fish, with an average initial weight and length of 4.25 g and 5.97 cm, were distributed among 20 experimental hapas, resulting in a stocking density of 10 fish per experimental unit. Fish fed a choline-deficient diet exhibited the lowest values for final weight, weight gain, visceral fat, and hepatosomatic index. Conversely, in terms of proximate composition, fish fed choline-deficient diets had the highest moisture content but the lowest crude fat content. Triglyceride levels in juvenile pacu were significantly higher in groups fed diets containing choline (400 to 1200 mg kg-1 ). We also observed significant differences in the cyan color of the liver (P < 0.05). Notably, we observed significant differences in the cyan coloration of the liver (P < 0.05). Other parameters did not exhibit significant changes in response to varying choline levels in the diets. Our study demonstrated that choline supplementation in P. mesopotamicus juveniles at an optimal concentration of 400 mg kg-1 significantly impacted growth, metabolism, productive performance, proximate composition, biochemical parameters, and liver color. These findings offer crucial guidance for aquaculture professionals, enabling them to enhance growth and health in P. mesopotamicus farming. Further research on choline's influence on lipid metabolism holds potential for more precise dietary recommendations, ultimately improving the efficiency and sustainability of aquaculture practices for this species.

A new design approach for dual-band power amplifiers based on dual-band HCC and bandpass filter

This paper introduces a novel design approach based on the dual-band harmonic control circuit and bandpass filter for dual-band power amplifiers. The circuit schematic of the proposed approach is constructed using four resonators and RFC inductors. The first two resonators are dedicated to controlling the second harmonics, while the third and fourth resonators serve as a harmonic blocker, allowing only the main signals to pass through to the load. Subsequently, all components are replaced by circuits based on microstrip elements, forming the proposed OMN. This OMN includes a novel wideband bias circuit, elliptically coupled resonators, and a new dual-band bandpass filter. To ensure compatibility with the transistor, a compensator line has been integrated. As a result, a dual-band power amplifier has been fabricated and measured at two operating frequencies, 2.1 GHz and 2.91 GHz. The measured values for drain efficiency, output power, and power gain at 2.1 GHz are 75.98%, 37.5 dBm, and 12.5 dB, respectively. Similarly, at 2.91 GHz, these values are 75.73%, 37.24 dBm, and 12.24 dB, respectively.

SEMANTRIS GOOGLE AI-BASED LEARNING TO ENHANCE STUDENTS’ VOCABULARY MASTERY

Semantris Google AI-Based Learning research has examined the students' disinterest and low level of vocabulary acquisition in English subject at MTs DDI Takkalasi. The students cited difficulty in pronunciation and other reasons for their lack of enthusiasm towards English as a difficult subject. This lack of interest and motivation is due to the absence of an interesting and enjoyable learning environment, which hinders students' ability to concentrate on their studies. In addition, the limited application of modern technology in the learning process makes this a problem that must be addressed given the increasingly advanced era. The research employed a quasi-experimental design to investigate the effectiveness of an intervention in improving students' English language proficiency. The study utilized a quantitative approach, conducting pre-test and post-test analyses to measure the impact of the intervention. The pre-test served as a baseline measurement, while the post-test assessed the outcomes after implementing the intervention. The researcher employed a quota sampling technique to select participants. The results of the Semantris Google AI-Based Learning study showed a significant difference in vocabulary improvement between the two groups, as evidenced by the T-count value of 6.858, exceeding the critical T-table value of 2.060. The rejection of the null hypothesis (H0) is supported by the mean N gain value of 0.4249 obtained from the experimental class, which falls within the moderate range according to the N gain table. This finding confirms that the use of Semantris Google AI-Based Learning is very effective in improving the vocabulary mastery of MTs DDI Takkalasi students.

Power Quality Improvement based on VSHDE Algorithm Incorporating Shunt Active Power Filter

The usage of the word Power quality in recent times acquired intensified interest due to the complex industrial processes. The usage of intelligent tools to improve power quality is increasing day by day, as assumption of present day power system as a linear model is unsatisfactory. This paper deals with analysis of Differential Evolution (DE), Hybrid Differential Evolution (HDE) and Variable Scaling Hybrid Differential Evolution for harmonic reduction in the source current with optimal tuning of PI controller gain values. Shunt Active power Filter is one of the better solution to suppress the source current harmonics which are induced into power system because of nonlinear loads. Current controller called HBCC is considered for gating operation of switches in Voltage Source Inverter. The Intelligent tuned PQ theory is used for reference current generation. The then obtained compensating currents are injected at point of common coupling for current disturbance mitigation. Simulations of MATLAB/SIMULINK environment of the present work shows the efficacy.

Design and control of a distillation sequence for the purification of bioethanol obtained from sotol bagasse (Dasylirium sp.)

Sotol bagasse (SB) is a byproduct generated during the fermentation of the sotol plant (Dasylirium sp.) for the production of a traditional alcoholic beverage in Mexico. In this study, a novel ethanol purification distillation sequence is proposed, utilizing ethanol produced from SB treatment as described by González-Chavez et al. (2022). Prior to purification, the ethanol-water mixtures exhibited ratios of 0.054 and 0.935. The proposed distillation sequence comprises three columns: i) depletion, ii) extraction (employing ethylene glycol as the solvent agent), and iii) solvent recovery. To assess energy consumption and controllability, three solvent:feed ratios (1.5:1, 2:1, 2.5:1) were examined, taking into account the feed to the second column. The lowest energy consumption was observed at 31 × 103 kW, corresponding to the 1.5:1 ratio. Optimal controllability was achieved at a solvent:feed ratio of 2.5:1, as evidenced by the lowest Integral Absolute Error (IAE) value of 3.3 × 10–3 and the highest proportional gain (Kc) value of 250. In summary, we leveraged previously reported experimental data to design a new distillation sequence with potential applications in the ethanol purification derived from SB fermentation. The outcomes of this investigation underscore the importance of promoting circular economy practices, particularly in the northern region of Mexico, where significant quantities of agrowastes are generated.

Realization of MoTe2 CMOS inverter by contact doping and channel encapsulation

The Fermi level pinning effect significantly limits the application of electrical devices based on two-dimensional materials like transition metal dichalcogenide. Here, a CMOS inverter, which is comprised of an n- and a p-MoTe2 FET with optimized properties, has been successfully fabricated by using contact doping and channel encapsulation methods. Contact doping is to control the polarity of MoTe2-FET and improve contact properties, which is achieved by laser irradiation in different environmental conditions. The channel of two MoTe2-FETs was encapsulated by hexagonal boron nitride (h-BN) to enhance carrier mobility and device stability. The fabricated CMOS inverter showed a very high gain value of 31 at V dd = 4 V at RT.

Honey Badger Algorithm Based PI Controller for DC Link Voltage Control of Solar Photovoltaic System Connected to Grid for Enhanced Power Quality

The parameters of the proportional integral (PI) controller used for DC link voltage control play a vital role in regulating the DC link voltage of grid-connected solar photovoltaic system that experiences heavy DC voltage fluctuation and various power quality issues due to integration of non-linear loads, varying irradiance and loading conditions. The existing strategies might fail to respond to the above complications due to fixed PI gains which restrict their scope of controlling domain. Therefore, adaptive PI gain values should be selected to quickly adjust to the varying conditions and dynamically obtain the optimal control settings. This article employs the honey badger algorithm (HBA), developed in Matlab to adaptively tune the PI controller gains value by minimizing the DC link voltage deviation. The advantages of using this technique over conventional PI controllers are its quick response, adaptability, stability, and optimal self-tuning process. The proposed algorithm has been tested under steady-state and dynamic conditions for different irradiation and loading conditions. Further, results of the proposed algorithm have been compared with PI controller and particle swarm optimization-PI controller to validate the efficacy of the proposed algorithm for grid-connected solar photovoltaic systems. It has been observed that the proposed algorithm maintains THD <3% in all the tested conditions.

Developing An Interactive Chemistry E-module Based on Problem-based Learning to Improve Critical Thinking Skills of High School Students

This study aims to develop an interactive chemistry E-module based on problem-based learning (PBL) to improve the critical thinking skills of high school students in class X and measure its feasibility. This research used the research and development method with the ADDIE model, which consists of 5 stages (Analysis, Design, Development, Implementation, and Evaluation). The tools used in this study were test tools and non-test tools, namely modified BSNP standard verification sheets and essay questions. The data analysis techniques used in this research were qualitative and quantitative. The results of the feasibility test from the materials specialist instructors, and chemistry teachers, as well as media specialists, an average result of 82.7% met the "very fair" criterion. An average result of 93.12% met the "highly feasible" criterion. Based on classroom learning experiments, the E-module can improve students' critical thinking skills by achieving an N gain value of 0.48 in the medium category. It was also evidence of a 55% increase in students' average critical thinking ability score using electronic modules and belonging to the critical category. When learning with the E module, a significant difference occurs at the significance level α=0.000.

Effect of Pig Synthetic Pheromones and Positive Handling of Pregnant Sows on the Productivity of Nursery Pigs.

Weaning is one of the most important stress events in the life of pigs, increasing the risk for health problems and reduced performance. The release of pheromones in pig stables can be considered an environmental enrichment and alleviate the negative effects of weaning stress in nursery pigs. The present study investigated the effect of synthetic pheromones on the performance of nursery pigs. The effect of positive handling of sows in the farrowing house on the performance of the offspring in the nursery was also investigated. The study was performed in a commercial pig farm and included 24 batches of weaned piglets (216 piglets per batch). Half of the batches originated from sows exposed to positive handling. This implied that music was played from 6.00 a.m. to 6.00 p.m. from the moment the sows entered the farrowing house until weaning and that they were subjected to backscratching from the day they entered the farrowing unit the day of farrowing. During the nursery period, half of the batches were treated, and half served as controls. Piglets of treated groups were exposed to a synthetic analog of the maternal pig appeasing pheromone (PAP) (SecurePig®, Signs, Avignon, France). The product consisted of a gel block from which the pheromones were slowly released into the room. Different performance parameters were measured during the nursery period. Neither the sow treatment nor the treatment with pheromones significantly influenced the performance of the piglets during the nursery period (p > 0.05). The median values (95% confidence interval) of average daily gain, namely 318 (282-338) vs. 305 (272-322) g/day, feed conversion ratio, namely 1.64 (1.51-1.71) vs. 1.70 (1.57-1.75), and number of antimicrobial treatment days, namely 16.9 (9.6-25.0) vs. 17.3 (9.5-25.0) days, were numerically better in the nursery pigs exposed to the pheromones compared to the control groups. Mortality however was numerically higher in the treated groups, namely 4.4 (2.8-6.8) vs. 3.2 (0.9-4.2)%. Under the conditions of the present production system, pigs exposed to the pheromone treatment during the nursery did not show a significant performance increase.

Incorporating body measurement traits to increase genetic gain of feed efficiency and carcass traits in Japanese Black steers.

The objective of the present study was to comprehensively evaluate whether body measurement traits, including body weight and body size, could be used as indicators of genetic selection for feed efficiency and carcass traits in Japanese Black steers. First, we estimated the genetic parameters for body measurements, feed efficiency, and carcass traits. Second, we estimated the correlated responses in feed efficiency and carcass traits when selection was applied to one or multiple-body measurement traits. In total, 4,578 Japanese Black steers with phenotypic values of residual feed intake (RFI) and residual body weight gain (RG) as feed efficiency traits and carcass weight (CWT) and beef marbling standard (BMS) as carcass traits were used. Eleven body measurement traits were measured at the start and finish of the fattening periods (BMT1 and BMT2, respectively), and their growth during the fattening period (BMT3) was used for genetic analyses. The results of genetic parameters showed that the heritability estimates were low to moderate (0.10 to 0.66), and the genetic correlations among body measurement traits were also estimated to be positively moderate to high in each measuring point (0.23 to 0.99). The genetic correlations of body measurement traits with RFI and BMS were estimated to be low (-0.14 to 0.30 and -0.17 to 0.35, respectively), but those with CWT were positively low to high (0.12 to 0.97). The genetic correlation estimates between BMT3 and RG were moderate to high (0.38 to 0.78). Second, correlated responses were estimated under positive selection for body measurement traits. Positive selection for BMT2 and BMT3 increased CWT and RG; however, positive selection for body measurement traits resulted in no change in RFI and BMS. Favorable directions of genetic gains, which were positive for RG, CWT, and BMS and negative for RFI, were obtained by selection indices, including multiple traits in BMT1. Our results suggest that using only one-body measurement trait as an indicator of genetic selection for RFI is difficult. However, body measurement traits can be indirect indicators of improved RG. Our results also suggest that genetic improvement of both RFI and RG without reducing CWT and BMS could be achieved using selection indices that account for a balance of body conformation using multiple-body measurement traits in Japanese Black cattle.

Analysis of DVB-T2 TV Broadcast Receiver with Comparison of Signal Reception Quality

Television is one of the most widely used media for receiving sound and image transmissions worldwide, particularly in Indonesia. Government regulations require all television broadcasters in Indonesia to cease analog broadcasts and transition to digital broadcasts. Consequently, a device known as the Set Top Box (STB), equipped with a low noise amplifier (LNA), converts DVB-T2 digital signals into images and audio suitable for analog televisions. Tests were conducted to evaluate its signal reception capabilities. These tests took place at four Palembang city locations, utilizing indoor and outdoor antennas. The results revealed that the device's signal strength ranged from -48.7 dBm, reaching 100% signal quality, to the weakest signal at -97 dBm. Moreover, an average difference of 6.9 dB was observed between indoor and outdoor testing for each frequency. Furthermore, analyzing the average signal strength based on distance showed that the highest strength of -56.2 dBm occurred at a distance of 1.5 km from the transmitter during outdoor testing. In comparison, the weakest strength of -91.6 dBm occurred at a distance of 1.8 km during indoor testing. Additionally, a signal strength comparison between test locations indicated that the most significant difference was between the Kamboja and Plaju locations. The LNA device achieved its highest gain value of 15.2 dB. Various factors, including antenna direction, obstructions such as buildings, antenna height, signal stability, and the distance between the transmitter and receiver, influence the signal quality.

GROWTH PERFORMANCE AND OXIDATIVE STATUS OF BROILER CHICKS FED DIETS SUPPLEMENTED WITH LYSOLECITHIN

Study was conducted to evaluate the effect of supplemental lysolecithin at different levels on the growth performance of broiler chicks. One hundred and eighty (180) day-old broiler chicks were used for the study. The birds were randomly allotted to five treatment groups of 36 birds each, and assigned to five treatments using a completely randomized design (CRD). The treatments were as follows: Treatment 1,0g lysolecithin; Treatment 2, 100g lysolecithin/100kg of feed; Treatment 3, 200g lysolecithin/100kg of feed; Treatment 4, 300g lysolecithin/100kg of feed and Treatment 5, 400g lysolecithin/100kg of feed. Each treatment was replicated 3 times with 12 birds per replicate. Feed and water were provided to the birds ad libitum. Results showed that there were significant differences (p &lt; 0.05) among the dietary treatments in final body weight, total weight gain and average daily weight gain, average daily feed intake, Feed Conversion Ratio FCR, Protein Efficiency Ratio PER and feed cost per kg gain values of the broiler chicks. Birds fed diets containing lysolecithin had significantly (p &lt; 0.05) higher final body weight, total weight gain and daily weight gain values than those fed the control diet (diet containing 0% lysolecithin). Birds in treatment 2 (diet containing 100g of lysolecithin /100kg of diet) had the highest average daily feed intake value. Birds fed diets containing lysolecithin had similar FCR values and these were significantly (p &lt; 0.05) lower than the FCR value of birds fed the control diet. Birds fed diets containing lysolecithin had similar PER values and these were significantly (p &lt; 0.05) higher than the PER value of birds fed the control diet. Birds fed diets containing lysolecithin had similar feed cost per kg gain values and these were significantly (p &lt; 0.05) lower than the feed cost per kg gain value of birds fed the control diet. It was concluded that the inclusion of lysolecithin as a feed additive in the diet of starter broiler birds improved feed efficiency, growth performance and reduced feed cost per kg weight gain of birds.

Nd, Gd:SrF&lt;sub&gt;2&lt;/sub&gt; crystal spectrum gain characteristic study on the broadband laser amplification

Spectral gain narrowing is one of the key factors affecting broadband amplification of ultrashort pulses. In this paper, the spectral gain characteristics in broadband amplification are studied theoretically and experimentally by using the characteristic of Nd,Gd:SrF&lt;sub&gt;2&lt;/sub&gt; crystal, i.e. the emission spectrum has a certain width at the higher stimulated emission cross section. Through the numerical simulation, the evolution law of output spectrum of the laser gain medium under different spectral gain lineshapes and different gain values is studied in detail. Theoretical calculation shows that the spectral gain narrows obviously with the increase of gain values of the traditional Gaussian emission spectrum and increasing the spectral bandwidth at the maximum stimulated emission cross section can obviously suppress the spectral gain narrowing. Furthermore, the spectral gain narrowing characteristics of the Nd,Gd:SrF&lt;sub&gt;2&lt;/sub&gt; crystal were studied experimentally. The Ф13mm×150mm Nd,Gd:SrF&lt;sub&gt;2&lt;/sub&gt; crystal was used as the gain medium which was pumped by flash lamps in the experimental study. The experimental results show that the output spectra of Nd,Gd:SrF&lt;sub&gt;2&lt;/sub&gt; crystals are not obviously narrowed when the input laser spectral width is 5nm (FWHM) and the gain is 140 times. The experimental results are consistent with the theoretical calculation and analysis. The crystal can work normally at the repetition rate of 0.2Hz and 1Hz in the experiment, but due to the influence of thermal effect, the gain will decrease to a certain extent with the increase of pump energy and repetition rate. The research results lay the foundation for the application of fluoride crystal in broadband chirped pulse amplification.

Machine Learning based calibration SDR in Digital Twin application

Software-Defined Radios are radio communications devices that have been growing and developing on a larger scale in recent years. Communications are intrinsically embedded in our day by day, thus presenting a higher motivation to use software-defined radios due to its attractive cost. However they present technical limitations. This paper addresses this problem, which is the non-linearity behaviour of gain and frequency in the LimeSDR-USB. That is, this equipment is used to produce a FM signal with an associated frequency and gain before being parameterised according to the internal parameters of each software-defined radio. Each software-defined radio presents a value of frequency and gain of its own, which correlates to the generated signals at the output level. To avoid this, machine learning networks were used, in which networks were trained to adapt to the non-linearity of these devices and correct it without the user noticing. This way, the user sets a desired frequency and gain in a signal, at the output of the software-defined radios, and a neural network calculates which values the software-defined radios should be parameterised, thus mitigating the non-linearity behaviour. This paper presents the evaluation of a laboratory prototype based on low-cost commercial software-defined radios equipment, to replace an expensive metrologically calibrated equipment used for radio frequency tests on a new concept of industrial test station, with description of the integration of Digital Twins, with their physical and virtual parts.