bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence and trends of developmental disabilities among US children and adolescents aged 3 to 17 years, 2018–2021
Authors: Li Qian , Li Yanmei , Zheng Juan , Yan Xiaofang , Huang Jitian , Xu Yingxia , Zeng Xia , Shen Tianran , Xing Xiaohui , Chen Qingsong , Yang Wenhan
Published: October 2023

Developmental disabilities prevalence seem to be high in countries around the world. It’s worth understanding the most recent prevalence and trends of developmental disabilities. The objective of this study is to examine the prevalence and trends of developmental disabilities of US children and adolescents. A total of 26,422 individuals aged 3–17 years were included. Annual data were examined from the National Health Interview Survey (2018–2021). Weighted prevalence for each of the selected developmental disabilities were calculated. The prevalence of any developmental disabilities in individuals was 16.65% (95% CI 16.03–17.26%), prevalence of attention deficit/hyperactivity disorder (ADHD), learning disability (LD), autism spectrum disorder (ASD), intellectual disability (ID), and other developmental delay were 9.57% (95% CI 9.09–10.06%), 7.45% (95% CI 7.00–7.89%), 2.94% (95% CI 2.67–3.21%), 1.72% (95% CI 1.51–1.93%), and 5.24% (95% CI 4.89–5.59%), respectively. Significant increases were observed for other developmental delay (4.02–6.05%) and co-occurring LD & ID (1.03–1.82%). Findings form this study highlight a high prevalence of any developmental disabilities, although no significant increase was observed. The prevalence of other developmental delay and co-occurring LD & ID were significantly increased. Further investigation is warranted to assess potentially modifiable risk factors and causes of developmental disabilities.
Interregional mobility in different age groups is associated with COVID-19 transmission in the Taipei metropolitan area, Taiwan
Authors: Jiang Wei-Ming , Wen Tzai-Hung , Huang Ying-Chi , Chiou Hung-Yi , Chen Wei J. , Hsiung Chao A. , Sytwu Huey-Kang , Tsou Hsiao-Hui
Published: October 2023

Before vaccines were introduced, mobility restriction was one of the primary control measures in the early stage of the coronavirus disease 2019 (COVID-19) pandemic. Because different age groups face disproportionate health risks, differences in their mobility changes affect the effectiveness of pandemic control measures. This study aimed to investigate the relationship between multiscale mobility patterns in different age groups and COVID-19 transmission before and after control measures implementation. Data on daily confirmed case numbers, anonymized mobile phone data, and 38 socioeconomic factors were used to construct negative binomial regression models of these relationships in the Taipei metropolitan area in May 2021. To avoid overfitting, the socioeconomic factor dimensions were reduced by principal component analysis. The results showed that inter-district mobility was a greater promoter of COVID-19 transmission than was intra-district mobility (coefficients: pre-alert, 0.52 and 0.43; post-alert, 0.41 and 0.36, respectively). Moreover, both the inter-district mobility of people aged 15–59 and ≥ 60 years were significantly related to the number of confirmed cases (coefficients: pre-alert, 0.82 and 1.05; post-alert, 0.48 and 0.66, respectively). The results can help agencies worldwide formulate public health responses to emerging infectious diseases.
The synthesis, thermal behaviour, spectral and structural characterization, and in silico prediction of pharmacokinetic parameters of tetraalkylammonium salts of non-steroidal anti-inflammatory drug nimesulide
Authors: Rybczyńska Małgorzata , Sikorski Artur
Published: October 2023

The synthesis, spectral properties, thermal analysis, structural characterization and in silico prediction of pharmacokinetic parameters of tetramethylammonium (compound 1) and tetraethylammonium (compound 2) salt of nimesulide were described in this article. Both compounds crystallize in the monoclinic P21/n space group, with one tetraalkylammonium cation and one nimesulide anion in the asymmetric unit and their crystal structures are stabilized by C–H···O hydrogen bonds between ions. Additionally, structures of title compounds are stabilized by π–π interactions (compound 1), or C–H···π interactions (compound 2) between nimesulide anions. The TG and DSC measurements show that compound 1 melts at a temperature higher than nimesulide, whereas the compound 2 melts at a temperature lower than nimesulide. The MALDI-TOF, 1H NMR, 13C NMR and ATR-FTIR analyses confirm the SCXRD study, that in compounds 1 and 2 nimesulide exists in an ionized form. Studies performed by SWISS ADME and ProTOX II tools, predict to be oral bioavailability of both salts obtained, and one of them (compound 1) is predicted to be well-absorbed by digestive system, while both compounds obtained are classified into toxicity class 4.
Process concepts and analysis for co-removing methane and carbon dioxide from the atmosphere
Authors: Sirigina Devesh Sathya Sri Sairam , Goel Aditya , Nazir Shareq Mohd
Published: October 2023

Methane is the second largest contributor to global warming after CO2, and it is hard to abate due to its low concentration in the emission sources and in the atmosphere. However, removing methane from the atmosphere will accelerate achieving net-zero targets, since its global warming potential is 28 over a 100-year period. This work presents first-of-its-kind process concepts for co-removal of methane and CO2 that combines the catalytic conversion of methane step (thermal/photo-catalytic) with CO2 capture. Proposed processes have been analyzed for streams with lean methane concentrations, which are non-fossil emissions originating in the agricultural sector or natural emissions from wetlands. If the proposed processes can overcome challenges in catalyst/material design to convert methane at low concentrations, they have the potential to remove more than 40% of anthropogenic and natural methane emissions from the atmosphere at a lower energy penalty than the state-of-the-art technologies for direct air capture of CO2.
Preparation and characterization of biopolymer-based adsorbents and their application for methylene blue removal from wastewater
Authors: Amiri Mohammad Javad , Raayatpisheh Maryam , Radi Mohsen , Amiri Sedigheh
Published: October 2023

In the present study, four biopolymer-based materials consisting of native corn starch (CS), phosphate corn starch (PS), starch nanocrystals (SNCs), and phosphate corn starch nanocrystals (PSNCs) were synthesized and used for methylene blue (MB) removal as a function of various parameters, including initial MB concentration (C0, 10–500 mg L−1), adsorbent dosage (Cs, 0.02–0.15 g), contact time (t, 5–15 min), solution pH (2–11), and temperature (25–45 °C). The removal percentage of MB increased dramatically upon increasing the biopolymer dosage, temperature, and pH; while it decreased upon increasing the initial MB concentration. The adsorption behavior of biopolymer-based materials towards MB was found to be accurately described by the pseudo-second-order kinetic and Langmuir isotherm models. According to the Langmuir model, the maximum adsorption capacities of the adsorbents were ordered as follows: PSNCs (88.53 mg g−1) > SNCs (79.55 mg g−1) > PS (73.17 mg g−1) > CS (63.02 mg g−1). PSNCs was able to remove 96.8% and 76.5% of 20 mg L−1 MB in greywater and petrochemical wastewater, respectively, at an optimum pH of 9 and retained 86.42% of its usability even after five adsorption–desorption cycles. The analysis of the surface charge of the adsorbents before and after MB adsorption, combined with the FTIR spectrum of MB-saturated biopolymer-based materials, provided evidence that electrostatic interactions was the primary mechanism involved in the adsorption of MB. Meanwhile, hydrogen bonding and π–π interactions were found to have a minor contribution to the adsorption process. Based on the results, it can be inferred that PSNCs has promising potential as an adsorbent for the treatment of MB-containing wastewater, owing to its exceptional properties, which include high adsorption capacity, low cost, and applicability for multiple reuses.
Protamine as a barrier against the angiogenic effect of insulin: a possible role of apelin
Authors: Yeganeh-Hajahmadi Mahboobeh , Mehrabani Mehrnaz , Esmaili Mojdeh , Farokhi Mitra Shadkam , Sanjari Mojgan
Published: October 2023

Insulin is proved to have angiogenic ability thereby may worsen the diabetic retinopathy (DR) progression. Insulin also triggers the expression of endogenous angiogenic peptide, apelin. Since protamine was introduced as an inhibitor of the apelin receptor, we hypothesized that use of protaminated insulin instead of non-protaminated insulin can decrease the negative role of insulin in progression of DR. Firstly, the incidence of DR was compared among three diabetic patient groups: an oral medication, non-protaminated insulin, and protaminated insulin (PIns). Proliferation and migration rate of HUVECs was measured after insulin, apelin, and protamine exposure. In clinical study, the chance of developing DR was 8.5 and 4.1 times higher in insulin group and PIns groups compared with oral group respectively. Insulin group had a chance of 9.5-folds of non-proliferative DR compared to oral group. However, the difference of non-proliferative DR between PIns and oral group wasn’t significant. In-vitro tests showed that concomitant use of insulin and apelin increases viability and migratory potential of HUVECs. However, protamine could reverse this effect. Protamine present in some insulins might show a promising protective role against diabetic retinopathy. Thus, protaminated insulins may be preferable in the treatment of diabetes.
Efficacy of tranexamic acid supplemented with local infiltration analgesia in reducing blood loss in patients undergoing unicompartmental knee arthroplasty
Authors: Wiktor Łukasz , Osadnik Bartłomiej , Damps Maria
Published: October 2023

This study aimed to investigate the efficacy of tranexamic acid supplemented with local infiltration analgesia in reducing blood loss in patients undergoing unicompartmental knee arthroplasty (UKA). This retrospective study was conducted on 176 individuals with a mean age of 64.27 (standard deviation [SD], 7.16) years undergoing unicompartmental cemented knee arthroplasty. The patients were divided into three groups according to patient blood management: I, patients without additional bleeding protocol (control group); II, patients intravenously administered tranexamic acid (TXA) (TXA group); and III, patients with exact TXA protocol combined with intraoperative local infiltration analgesia (LIA) (TXA + LIA group). Blood loss was measured as a substitute for blood loss by the maximal haemoglobin (Hb) drop compared with the preoperative Hb level. The mean Hb drops for the control, TXA, and TXA + LIA groups were 2.24 (16.0%), 2.14 (15.4%), and 1.81 (12.6%) g/dl, respectively. The mean hospitalisation days for patients in the control, TXA, and TXA + LIA groups were 5.91 (SD 1.24), 5.16 (SD 0.95), and 4.51 (SD 0.71) days, respectively. The combination of TXA with LIA reduces perioperative blood loss for patients after UKA.
Near-infrared light activatable niosomes loaded with indocyanine green and plasmonic gold nanorods for theranostic applications
Authors: Prince Yumnam , Hiremath Netra , Vankayala Raviraj
Published: October 2023

Light-mediated theranostic platforms involve the use of agents (small molecules/nanomaterials), which can absorb light to produce either heat or reactive chemical species (RCS) and emit fluorescence.
Amorphous versus nanocrystalline RuO2 electrocatalysts: activity and stability for oxygen evolution reaction in sulfuric acid
Authors: Beppu Kosuke , Obigane Kazuki , Amano Fumiaki
Published: October 2023

Amorphous RuO2 have high OER activity but are unstable during the OER in 0.1M H2SO4. RuO2 nanoparticles with high crystallinity simultaneously achieved high OER activity and stability.
Photo-responsive disassembly of supramolecular polymer bottlebrushes in water
Authors: Harvey Luke , Guigner Jean-Michel , Bouteiller Laurent , Nicol Erwan , Colombani Olivier
Published: October 2023

Azo-(U-PEO)2 self-assembled into long supramolecular nanocylinders in water and disassembly was triggered by photo-induced trans → cis isomerization of azobenzene units.
Wavelength-resolved near infra-red light induced free-radical polymerization
Authors: Neidinger Philipp , Davis Joshua , Carroll Joshua A. , Kammerer Jochen , Jaatinen Esa , Walden Sarah L. , Unterreiner Andreas-Neil , Barner-Kowollik Christopher
Published: October 2023

A near infra-red action plot from 620 to 950 nm for gold nanorod (AuNR) mediated free-radical polymerization is reported, probing the wavelength-by-wavelength monomer to polymer conversion with an identical number of photons at each wavelength.
Spontaneous generation of singlet oxygen on microemulsion-derived manganese oxides with rich oxygen vacancies for efficient aerobic oxidation
Authors: Tang Jun , Chen Junbao , Zhang Zhanyu , Ma Qincheng , Hu Xiaolong , Li Peng , Liu Zhiqiang , Cui Peixin , Wan Chao , Ke Qingping , Fu Lei , Kim Jeonghun , Hamada Takashi , Kang Yunqing , Yamauchi Yusuke
Published: October 2023

We fabricated a range of Ny-MnOx using compartmentalized microemulsion crystallization followed by post-calcination. These materials have the unique ability to generate sufficient 1O2 at room temperature without requiring an external field.
Thermoelectric properties of the aliovalent half-Heusler alloy Zn0.5Ti0.5NiSb with intrinsic low thermal conductivity
Authors: Kennedy Blair F. , Kimber Simon A. J. , Checchia Stefano , Shawon A. K. M. Ashiquzzaman , Zevalkink Alexandra , Suard Emmanuelle , Buckman Jim , Bos Jan-Willem G.
Published: October 2023

Aliovalent substitutions lead to bond disorder and low lattice thermal conductivities in half-Heusler thermoelectrics.
Synergistic wound repair effects of a composite hydrogel for delivering tumor-derived vesicles and S-nitrosoglutathione
Authors: Nan Wenbin , Wang Fan , Wang Hao , Xiao Wenchi , Li Linxiao , Zhang Chao , Zhang Yulu , Dai Linna , Xu Zhihao , Wan Guoyun , Wang Yongxue , Chen Hongli , Zhang Qiqing , Hao Yongwei
Published: October 2023

Tumor extracellular vesicles (tEVs) from 4T1 cells could induce macrophage polarization switching of M1 to M2. Synergistic wound repair effects of a composite hydrogel for delivering tEVs and S-nitrosoglutathione could be achieved.
Quantifying polaron densities in sequentially doped conjugated polymers: exploring the upper limits of molecular doping and conductivity
Authors: Murrey Tucker L. , Berteau-Rainville Melissa , Gonel Goktug , Saska Jan , Shevchenko Nikolay E. , Fergerson Alice S. , Talbot Rachel M. , Yacoub Nichole L. , Zhang Fengyu , Kahn Antoine , Mascal Mark , Salzmann Ingo , Moulé Adam J.
Published: October 2023

Conjugated polymers are sequentially doped to control film conductivity and optical properties. (1) Carrier fractions (measured via optical absorbance), (2) polymer site densities, and (3) dopant volumes are used to calculate polaron densities.
Repetition Priming Treatment for Anomia: Effects of Single- and Multiple-Exemplar Protocols
Authors: Silkes JoAnn P.
Published: October 2023

Introduction:

Repetition priming can lead to improved naming ability in people with aphasia, but concerns have arisen from prior research about using only a single picture exemplar for each target. Specifically, it is unclear whether the observed improvements were due to learning simple correspondences between particular words and pictures rather than changes at a deeper level of lexical–semantic processing. In addition, implications for generalization after training with single exemplars were unclear. This study replicated and extended previous work to address these questions.

Method:

Five participants with chronic aphasia participated in this repeated-measures design study, which repeatedly paired words and pictures with no feedback provided. Two participants engaged in a single-exemplar condition, with a single picture exemplar of each target used for every presentation of that target. The remaining three participants engaged in a multiple-exemplar condition, with several different pictures used for each target. Half of these targets used training pictures during naming probes, whereas half did not.

Results:

Primed items led to greater improvements in naming than items that were practiced but not primed. The data indicate that improvements may extend beyond stimulus-specific correspondences. Maintenance and generalization effects were mixed.

Conclusions:

These data provide further support for the efficacy of repetition priming treatment for anomia. Implications and future directions are discussed.
The miniJPAS and J-NEP surveys: Identification and characterization of the Lyα emitter population and the Lyα luminosity function at redshift 2.05 < z < 3.75
Authors: Torralba-Torregrosa A. , Gurung-López S. , Arnalte-Mur P. , Spinoso D. , Izquierdo-Villalba D. , Fernández-Soto A. , Angulo R. , Bonoli S. , González Delgado R. M. , Márquez I. , Martínez V. J. , Rahna P. T. , Vílchez J. M. , Abramo R. , Alcaniz J. , Benitez N. , Carneiro S. , Cenarro J. , Cristóbal-Hornillos D. , Dupke R. , Ederoclite A. , Hernán-Caballero A. , López-Sanjuan C. , Marín-Franch A. , Mendes de Oliveira C. , Moles M. , Sodré L. , Taylor K. , Varela J. , Vázquez Ramió H.
Published: October 2023

We present the Lyman-α (Lyα) luminosity function (LF) at 2.05 < z < 3.75, estimated from a sample of 67 Lyα-emitter (LAE) candidates in the Javalambre Physics of the Accelerating Universe Astronomical Survey (J-PAS) pathfinder surveys: miniJPAS and J-NEP. These two surveys cover a total effective area of ∼1.14 deg2 with 54 narrow band (NB) filters (FWHM ∼ 145 Å) across the optical range, with typical limiting magnitudes of ∼23. This set of NBs allowed us to probe Lyα emission in a wide and continuous range of redshifts. We developed a method for detecting Lyα emission for the estimation of the Lyα LF using the whole J-PAS filter set. We tested this method by applying it to the miniJPAS and J-NEP data. In order to compute the corrections needed to estimate the Lyα LF and to test the performance of the candidate selection method, we built mock catalogs. These include representative populations of LAEs at 1.9 < z < 4.5 as well as their expected contaminants, namely low-z galaxies and z < 2 quasi-stellar objects (QSOs). We show that our method is able to provide the Lyα LF at the intermediate-bright range of luminosity (43.5 ≲ log10(LLyα/erg s−1) ≲ 44.5) combining both miniJPAS and J-NEP. The photometric information provided by these surveys suggests that our samples are dominated by bright, Lyα-emitting active galactic nuclei (i.e., AGNs). At log10(LLyα/erg s−1) < 44.5, we fit our Lyα LF to a power law with a slope of A = 0.70 ± 0.25. We also fit a Schechter function to our data, obtaining the following: log10(Φ∗/Mpc−3) = −6.30−0.70+0.48, log10(L∗/erg s−1) = 44.85−0.32+0.50, and α = −1.65−0.27+0.29. Overall, our results confirm the presence of an AGN component at the bright end of the Lyα LF. In particular, we find no significant contribution of star-forming LAEs to the Lyα LF at log10(LLyα/erg s−1) > 43.5. This work serves as a proof of concept for the results that can be obtained with the upcoming data releases of the J-PAS survey.
Data verification for forecasting of building energy consumption
Authors: Khudayarov Muzaffar , Qurbonov Sarvar
Published: October 2023

One of the necessary procedures prior to monitoring the energy consumption of buildings is the procedure of verification of the initial data on energy consumption. It is always applied in cases where there is even the slightest doubt in the correctness of the initial data. The article deals with the verification of data on energy consumption in buildings, which includes the implementation of procedures for detecting and replacing null, erroneous, absolutely equal, and recovery of lost data on energy consumption. To solve this problem the article presents a number of methods included in the program “Statistical data verification” developed in MATLAB environment. As an example, the process of verification of data on energy consumption in buildings, which include hospitals, polyclinics, rural health centres is presented.
Photovoltaic-based Distributed Generation Allocation in Distribution Network for Energy Loss Minimization
Authors: Khasanov Mansur , Kamel Salah , Jurado Francisco , Kurbanov Abror , Jalilov Urinboy
Published: October 2023

Nowadays, there is a global consensus that integrating renewable energy sources (RESs) is highly needed to meet the increasing electricity demand and reduce the overall carbon footprint of energy production. However, large-scale integration of RES-based distributed generation (DG) units often poses several technical challenges in the system from stability, reliability, and power quality perspectives. However, these problems are usually mitigated by the optimal integration of DG units in the distribution networks (DNs). In this regard, the optimal sizing and placement of the DGs are crucial. Otherwise, network performance will deteriorate. This paper proposes to apply a novel population-based technique called the dung beetle optimization (DBO) algorithm for the optimal allocation of Photovoltaic (PV) based DG units to minimize total active energy loss subject to equality and inequality constraints in the DN. A DBO is inspired by the behaviours of dung beetles, including ball-rolling, dancing, foraging, stealing, and reproducing. A standard 33-bus system has been used to demonstrate the proposed method's effectiveness. The simulation results and comparison with other techniques demonstrate our proposed approach's significant energy loss reduction and a suitable voltage profile.
Analysis of photovoltaic power station (PPS) modeling using artificial neural network and PVsyst software
Authors: Mirzabaev Akram , Mirzabekov Sherzod , Kodirov Dilshod , Makhkamov Temur , Mirzaev Askar
Published: October 2023

The possibility of using the method of artificial neural networks to analyze the modes of complex electric power systems with integrated large photovoltaic stations is considered. Based on the correlation analysis, the main factors influencing the energy parameters of photovoltaic power plants were selected and the boundary conditions for the Pearson coefficient were determined. The algorithm of the developed program for calculating the modes of electric power systems using neural networks is described, which makes it possible to more accurately predict generation, taking into account climatic conditions. On the example of calculations of the modes of the South-Western part of the energy system of Uzbekistan, taking into account the change in power flows as the generation of the Navoi photovoltaic plant with a capacity of 100 MW changes, a comparative analysis of the results obtained by calculation with real measurements was carried out.
Power Losses of Asynchronous Generators Based on Renewable Energy Sources
Authors: Toirov Olimjon , Taniev Mirzokhid , Hamdamov Muzaffar , Sotiboldiev Abdurakhmon
Published: October 2023

This article discusses the possibility of using asynchronous generators in wind turbines, in particular asynchronous generators with phase rotors, in parallel with the network. Currently, due to the decrease in non-renewable energy sources around the world, the use of renewable energy sources, especially wind energy, is being considered. Also in this article, the power losses and energy balance of asynchronous generators with a phase rotor, all losses in an asynchronous generator, its efficiency, and torque are considered. In addition, a functional diagram of an asynchronous generator in a wind turbine has been developed, as have methods for simplifying calculations due to the generator substitution scheme. Due to this, methods for calculating the impedance of an asynchronous generator are given. With the help of an experimental research stand, the state of a number of parameters was analyzed during the parallel operation of an asynchronous generator with a phase rotor and a network. Taking into account that the indicators of the wind potential of land plots identified for the construction of wind turbines in Uzbekistan are higher than the average indicators of existing wind turbines in the world, it is assumed that the use of asynchronous generators in wind farms in the near future is considered promising.
Enhancing the efficiency of cold water-soluble fertilizers through electrohydraulic technology
Authors: Turdiboyev Abduvali , Akbarov Dilmurod , Toshev Tajiddin , Sayfiyev Sardor , Mamutov Muxammedgaliy
Published: October 2023

This article discusses the improvement of the efficiency of cold water-soluble fertilizers through the use of electrohydraulic technology to facilitate the assimilation of nutrients in plants. The issue of enhancing the efficiency of fertilizing plants through electrohydrolysis using cold water-soluble organic and mineral nutrients is examined. According to the detailed results of nutrient assimilation technologies in plants, the amount of nutrients absorbed by plants constitutes 30-40% of the fertilizer. To enhance the efficiency of nutrient assimilation in plants, it is necessary to break down the nutrients in the cold water-soluble composition into small particles, increase plant absorption capacity, and simultaneously demand the neutralization of bacteria in the cold water-soluble fertilizer composition. By applying the electrohydraulic effect to the cold water-soluble fertilizer, the following parameters were identified for maximum fragmentation of solid particles in the fertilizer composition: discharge voltage of 24 kV, 175 pulses, and a capacitor capacitance of 0.8 μF. This process allows for the fragmentation of solid particles in the fertilizer composition down to 0.002 mm, which is challenging for plants to assimilate on their own. The regime and parameters of electrohydraulic treatment, ensuring the fragmentation of solid particles in cold water-soluble fertilizers down to 0.002 mm, were determined, and this can increase the efficiency of the fertilizer for plant growth by 33-37 qq.
Effect of nickel doping on the spectral sensitivity of silicon solar cells
Authors: Zikrillayev Nurillo , Kenzhaev Zoir , Ismailov Timur , Kurbanova Ugolay , Aliyev Bakhadir
Published: October 2023

In the modern industrial production of solar cells (SC), there is a growing trend to utilize “solar silicon” as the base material due to its cost-effectiveness. However, solar silicon possesses a drawback - it has a shorter lifetime of minority charge carriers (MCC), making it challenging to achieve high efficiency in solar cells. To address this limitation and improve the efficiency of solar cells based on “solar silicon,” two key objectives need to be met. Firstly, it is essential to increase the lifetime of photogenerated charge carriers. Secondly, there is a need to minimize both optical and electrical energy losses. To achieve an increase in the lifetime of minority charge carriers in SCs, a process called gettering can be employed. This process involves utilizing clusters of nickel atoms to trap uncontrolled impurity atoms. The paper presents the results of a study on the additional doping of silicon solar cells with nickel atoms, for factors affecting the long-wave and short-wave efficiency. Nickel doping has been shown to increase the efficiency of solar cells. It is determined that in the visible region of the spectrum the spectral sensitivity of a silicon solar cell doped with nickel is higher up to 25÷35% due to a decrease in surface recombination. Technological recommendations for nickel doping of single-crystal silicon solar cells are proposed to be combined without significant changes with the standard technological process for manufacturing solar cells.
Effectiveness of compaction of the initial well grid in the late stage of oil and gas field development
Authors: Karshiev Abduhoshim , Razzakov Otabek , Sakhatov Bahodir , Sultanov Nodir
Published: October 2023

The Kruk oil and gas field development is characterized by its geological structure and various technological indicators. A comprehensive evaluation of the field’s properties has allowed for the determination of recoverable oil reserves using water-based oil displacement techniques. Two scenarios were considered for field development: one with an initial well mesh and another with a densified well grid. The results demonstrated the high efficiency of well grid densification during the later stages of field development. This optimization strategy led to a notable increase in the rate of oil withdrawal and enhanced the recovery of geological reserves. The densification of the well grid improved the overall efficiency of oil production and contributed to maximizing the extraction of available oil reserves. The findings highlight the importance of employing advanced technological strategies to enhance oil and gas field development. By carefully considering the geological structure and implementing well grid densification when appropriate, it is possible to optimize oil recovery, increase productivity, and effectively utilize the available geological reserves in the Kruk field.
Study on equations of curves of the squeezing machines’ contact of rolls
Authors: Turgunov Komil , Abdullaev Akhror
Published: October 2023

This study deals with the issues of mathematical modeling of curves of contact of rolls of squeezing machines. The paper deals with the issues of mathematical modeling of curves of contact of rolls of squeezing machines. Equations are obtained the of curves contact of the rolls of the squeezing machine, in which the upper roll is mixed relative to the lower roll towards the movement of the processed material, the processed material is fed so that the line, which is a continuation of its front end, passes through the axis of rotation of the upper roll. It was been established that the contact curves of the rolls depend mainly on the deformation and geometric parameters of the processed material and both rolls, as well as the coefficients of friction between the contacting bodies.
Study on contact lines of rolls of two-roll modules
Authors: Annaev Nuriddin , Rasulev Akmal
Published: October 2023

The results of solving the main problems of contact interaction in squeezing machines are presented, when the deformation of the contacting bodies is given by the Kelvin Voigt models. Analytical expressions are found that describe the shape of the contact line of the rolls, as well as the patterns of distribution of normal and tangential forces. It has been established that one of the main factors determining the roll contact lines is the ratio of the strain rates of the material being processed and the roll coating. It is revealed that the point where the shear stresses change their signs is located in the sticking area.
Study on issues of hydrodynamics of the roll squeezing process
Authors: Kurbanova Firuza , Aliboev Kakhramon , Mazhidov Samariddin
Published: October 2023

The laws of distribution of hydrodynamic pressure and changes in extracted fluid in the pressing area are developed; they take into account the phenomena of contact interaction in the roll pair of the pressing machine. Hydraulic pressure in the compression zone increases from zero at the initial point of contact to a maximum value at a point lying on the line of centers. The distribution of hydraulic pressure in the recovery zone depends on the position of the water division point. It was revealed that the pattern of change of the removed fluid in the recovery zone depends on the position of the water division point. At the beginning of the recovery zone and up to the point of water division, the fluid flows from the coating into the material, and beyond this point, fluid is reabsorbed from the roll coating, and the amount of fluid removed from the material in the recovery zone is greater than the amount of absorbed fluid.
Study on vibration of the saw cylinder and its critical speed
Authors: Sulaymonov Rustam , Yuldashev Amirjon
Published: October 2023

The force impact of the 130 saw cylinder of gins 4DP-130 and 5DP-130 was studied. It was determined that due to the significant weight of the saw cylinder, when it is rotated at 730 rpm, its radial runout increases, leading to shaft deflection and wear of its neck for bearing fit, rapid wear of the working part of the grates in the grate and blunting of saw teeth when saw teeth touching the grate, which led to their rapid wear. Increased wear of the saw blade and grate, increases the consumption of imported saws and grates, reducing their service life. In addition, due to the increase in the radial runout of the saw cylinder, it was impossible to set the necessary gaps of 1.5-2.0 mm along the entire length between the saw cylinder and the air chamber nozzle, which did not ensure complete removal of the fiber from the saw teeth and its transportation to the fiber discharge channel. This led to a decrease in the productivity of the gin and the daily production of fiber. When studying the saw cylinder, it was revealed that with a decrease in the mass of the shaft, the deflection and vibration of it should decrease, increasing stability. In this regard, a hollow shaft for saw gin is proposed. Theoretically, the critical speed of a hollow shaft for 130 saw gins is considered. It is determined that for the stability of the saw cylinder, its critical speed must be.
Role of fillers in the production of wood-polymer composites
Authors: Aliev Sunnatilla , Egamberdiev Elmurod , Turabdjanov Sadriddin , Rashidov Shokhzodbek , Juraev Asror
Published: October 2023

During the examination and analysis of the physical and mechanical properties of wood polymer composites (WPC), researchers have consistently observed alterations in the strength and durability of the material. These changes have been found to correlate with variations in the wood content of the composite as well as its sensitivity to different climatic conditions. This dynamic relationship between composition, environmental factors, and material performance is a critical aspect of scientific research in this field. Moreover, the manufacturing processes and technologies employed in the production of WPC materials are intricately linked to these factors. Researchers carefully tailor production methods and select appropriate fillers based on the specific characteristics mentioned above. The inclusion of wood fillers in the composite composition is an important area of investigation, as it significantly impacts the resulting material properties. This systematic exploration of how different wood fillers influence the properties of the composite material is an integral part of the scientific research conducted in this domain. By comprehensively understanding these relationships, researchers can optimize the composition and production methods of WPC materials to enhance their strength, durability, and overall performance in varying climatic conditions.
Justification of the bottom softening parameters of working organ with a sloping column
Authors: Mamatov Farmon , Irgashev Dilmurod , Buriev Muhriddin , Ganiyev Bekzod
Published: October 2023

At present, cultivator plows used in horticulture in Uzbekistan have a number of serious shortcomings. Their quality of work does not meet agrotechnical requirements. The purpose of study is to substantiate the parameters of lower ripper the working body with an inclined rack. The authors proposed a working body with an inclined rack, equipped with upper and lower rippers. The lower ripper loosens the lower soil layer. The scheme of a plow-ripper with improved working bodies is given. Theoretical studies were carried out using the laws of theoretical mechanics. In experiments, the height of irregularities at the bottom of arable land and traction resistance were taken as a criterion for evaluating the performance of a plow-ripper. Based on the results of theoretical studies, dependencies were obtained that allow determining the parameters lower ripper. According to the results of this proven research, the coverage width the bottom softener is in the range 9.5-9.9 cm, and its grinding angle is in the range of 16,3-27º, in order to ensure the required level of coulters in the bottom the plow. The angle of installation the blade in relation to the direction of movement should be 30º.
Study on the development of a rotary soil softener
Authors: Nishonov Botirjon , Normirzaev Abdukаyum , Tukhtabayev Mirzokhid
Published: October 2023

This article presents the technological working process of the rotary softener developed for the chisel-cultivator; results of experimental studies carried out to justify its parameters. The type of soil and its physic-mechanical properties are the main factors in the selection of the working bodies of the soil tillage machine and assessment of aggregate performance. The researches are carried out mainly in grassy, pale gray and barren soils, and the physic-mechanical properties of the soil in irrigated fields of the Republic of Uzbekistan have been sufficiently studied. However, in a short period of time, machines that can treat a large area with high quality and at the level of demand have not been created. In order to choose the optimal type of rotary softener, based on the physical and mechanical properties of the soil, rotors equipped with different types of blades were prepared and tested. A rotary tiller for a chisel cultivator was compared with a chisel tiller and leveler, and cost effectiveness, labor and operating costs were calculated.
Analysis of the mineralogical composition of soil samples: Case study of Karmana district
Authors: Tagayev Ilhom , Juraev Shohrux , Маsharipova Muxabbat , Achilova Sanobar , Temirov Uktam
Published: October 2023

This article deals with the issues of determining the mineralogical composition of soil samples in the city of Navoi and the Karmaninsky district (the settlement of Khazora, 24 km from the city) and identifying the degree of salinization of these old irrigated soils in the region. To determine the mineralogical composition of soil soils, the X-ray diffraction method of research was used, and to determine the functional groups of carbon, sulfur, and chlorine, IR spectrometric analysis of samples was used. The studies carried out made it possible to establish a carbonate type of salinity for the city of Navoi, and for the Karmaninsky district, the dominance was noted first of carbonate - 45.4%, then sulfate 28.8%, and only lastly did the third type of salinity appear, represented by chloride - 0.8%, found on the surface layer of the soil (0-0, mm).
Statistical assessment of the comparative breaking strength of yarns with different fiber composition
Authors: Kazakova Dilafruz , Abbazov Ilkhom , Yuldoshev Khurshid , Tojimuradov Sardor , Baratova Kumush
Published: October 2023

This article studied the factors affecting the quality of cotton yarn. The properties of cotton fiber and their changes in technological processes play an important role in product production. Therefore, cotton fibers with different staple lengths of 28.5, 29.0, and 29.5 mm were used in the test work. Because it is advisable to use long fiber cotton fiber to get single yarn spun for sewing threads, for each option, different twists on the thread, i.e. the number of twists in 1 meter of thread were 850, 900, 950 b/m. The strength of individual threads ensures the quality of the product obtained from it, so we use the above number of twists. In order to determine the relative breaking strength of a single thread for sewing threads, experimental tests were conducted. According to the conducted experimental tests, 2 incoming factors were selected. As an output parameter, the relative tensile strength of the yarn, sN/tex (U) as input parameters, the effect of fiber staple length in mm, and the number of twists on the b/m indicator were studied based on the experiment. As a result of theoretical studies, the optimal value of the relative breaking strength of the thread from 16.25 sN/tex to 17.54 sN/tex, the staple length of the fiber should be more than 29.5 mm, and the number of twists should be 900 twist/meter It was determined that it should be. Based on the obtained conclusions, scientific and research work was carried out in the control enterprise. Based on the results of this research, the preliminary results of choosing the direction of further research were obtained. For this, LOTs were organized in the enterprise in various options. LOT-1 consists of Porloq-4, LOT-2 Bukhara-102, LOT-3 Sultan varieties. Based on the research results, the coefficient of variation in the linear density of yarns with different fiber content, the coefficient of variation in the number of twists, breaking strength, the variation coefficient in breaking strength, elongation at break, the coefficient of variation in elongation at break, comparison of the coefficients of variation for breaking strength and specific breaking strength were studied. When analyzing the effect of the composition of the fiber mixture on the physical-mechanical properties of the yarns for 3 LOTs, it was seen that the quality indicators of the yarns obtained from the LOT-1 mixture are higher than the indicators of the yarns obtained from other mixtures.
Ways to increase the efficiency of the seed linting process
Authors: Norboyev Utkir , Sulaymonov Rustam
Published: October 2023

The current state of local and foreign linters has been studied. It has been determined that local 5LP linters when linting cotton seeds do not meet the increased requirements of ginneries in cotton-textile clusters. The practice of operating serial 5LP linters shows that the actual performance of a 5LP linter is on average 50% of that stated in the passport. It was revealed that one of the main reasons for the decrease in the efficiency of the linter is not the perfection of the working body-turner. Due to the imperfection of the agitator design, the density of the seed roller increases, the quality of the lint and seeds deteriorates, and the productivity of the linter decreases. Studies of the Chinese-made MR-160-11C linter operated at the Djuma cotton plant in the Samarkand region showed an increase in the dust content of the air in the workshop due to the absence of a cleaning section for cleaning seeds in the feed system. At the same time, the increase in mechanical damage to seeds by 1.5-2.5% and clogging of the lint by 2.5-3.5% is higher than recommended by the regulations. Due to increased seed damage, these linters were not used to process plant seeds. An increase in the degree of clogging of the lint and an increase in the amount of lint with a short staple length in its composition sharply reduced the quality of the lint. When linting, the productivity of machines for seeds decreased by an average of 50-60%, for linting by 25-35% compared to passport data. To increase productivity and improve the quality of lint and seeds, a new design agitator for the 5LP linter was proposed.
A brief review on biological and chemical activities of flavonoids in plants
Authors: Turatbekova Aidai , Babamuradova Lola , Tasheva Umida , Saparbaeva Nasiba , Saibnazarova Gulnora , Turayeva Matluba , Yakubov Yusufboy
Published: October 2023

Flavonoids are a group of plant pigments, the combination of which determines one or another color of flowers and fruits. In plants, flavonoid dyes play the role of light filters that protect tissues from negative influences. Flavonoids are widely distributed secondary metabolites with different metabolic functions in plants. Flavonoids - a group of polyphenolic compounds C6-C3-C6 -series that are synthesized exclusively in higher plants. This review considers four main functions of flavonoids in the plant body. These compounds take an active part in redox processes, in plant reproduction they play the role of bright attractants for insects and animals. An important function of flavonoids is to protect plants from external adverse abiotic and biotic factors. They are signal molecules in auxin metabolism, as well as at various stages of the plant symbiosis with mycorrhizal fungi and nitrogen-fixing bacteria.
Study on morphological parameters of the sweet almond nut (Amygdalus communis l.)
Authors: Namozov Jasurbek , Yuldashov Yakubjon , Namozov Jasurbek
Published: October 2023

This article delves into the morphological features of various sweet almond (Amygdalus communis L.) varieties and forms, with the aim of analyzing their characteristics and applying the findings to obtain new types of almonds. Thirteen different sweet almond varieties were studied, including their total weight, kernel mass, number of seeds, and seed ratio. The results showed that one genotype (Qamashi-3) had medium to large nuts, while the other twelve genotypes had small nuts. All genotypes had easily peeled shells. Of the selected varieties, 15.38% were very large, 46.15% were medium to large, and 38.46% were small-fruited. The length, width, and thickness of the nut varied from 22.0 mm to 39.2 mm, 14.0 mm to 23.0 mm, and 11.0 mm to 16.5 mm, respectively. The thickness of the seed coat ranged from 1.5 mm to 3.1 mm. The number of nuts per 1 kg differed across varieties, ranging from 139 to 1076 pieces. Two genotypes had very hard shells (Tosh almond, Qamashi-3), four had hard shells, three had medium-hard shells, and six had soft shells. Most of the genotypes had sweet grains (12 genotypes), while one had a bittersweet taste. Overall, the studied sweet almond genotypes are important for expanding the genetic base in Uzbekistan through hybridization with each other or with standard varieties.
A brief overview on the methods for extraction and identification of flavonoids
Authors: Turatbekova Aidai , Mirzarakhmetova Dilbar , Jumaniyozov Jumaniyoz , Khudayberganov Erkaboy , Toshpulatov Nusratillo , Rakhmatov Abdugani , Muzafarov Shavkat
Published: October 2023

Flavonoids are active metabolites of plant cells. The significant biological role of these compounds is evidenced by the nature of their distribution in the plant. Flavonoids play an important role in plant reproduction, development and accumulation of pollen, and their content also determines the color of flowers, fruits, and plant seeds. Most flavonoids are found in actively functioning organs: leaves, flowers, fruits (color, aroma), seedlings, as well as in integumentary tissues that perform protective functions. Different organs and tissues differ in the quantity and qualitative composition of flavonoids. Relatively recently, it was found that flavonoids also influence signaling processes occurring in living systems due to specific interactions with proteins that perform regulatory functions. Numerous data have been accumulated on the influence of these compounds on other protein and non-protein structures, which can lead to changes in the functional state of cells and the entire organism as a whole. Despite the fact that currently the redox properties of phenolic compounds are not given so much importance, their comprehensive study still remains an important task. In addition, numerous studies confirm that flavonoids act as effective phytoalexins, exhibiting a wide range of antibacterial and antifungal activities. After all, a significant role of flavonoids is their function of protecting against various unfavorable factors for plants, such as temperature fluctuations, the influence of ultraviolet rays, attacks by viruses, bacteria, and parasites. A correlation has been established between their content in plants and plant resistance to fungal diseases and some pests. The appearance of these compounds in plants in response to the action of parasitic fungi of cultivated plants and inhibition of the growth of fungal mycelium is considered a protective reaction. Flavonoids with antimicrobial activity are found in large quantities in the seed coat. This review paper highlights the basic technologies for extraction and identification of flavonoids from different type of plants.