Fast Growth Research Articles

How hospital autonomy affects provider payment reform effectiveness.

Provider payment reforms (PPRs) have demonstrated mixed results for improving health system efficiency. Since PPRs require health care organisations to interpret and implement policies, the organizational characteristics of hospitals may affect the effectiveness of PPRs. Hospitals with more autonomy have the flexibility to respond to PPRs more efficiently, but they may not if the autonomy previously facilitated behaviours that counter the PPR's objective. This study examines whether hospitals with higher autonomy responds to PPRs more effectively. We used data from a matched-pair, cluster randomized controlled PPR intervention in a resource-limited Chinese province between 2014 and 2018. The intervention reformed the reimbursement method from the publicly administered New Cooperative Medical Scheme (NCMS) from fee-for-service to global budget. We interacted measures of hospital autonomy over surplus, hiring, and procurement (drugs, consumables, equipment, and overall index) with the difference-in-difference estimator to examine how autonomy moderated the intervention's effect. Autonomy over surplus (p<0.01) and procurement of equipment (p<0.01) were associated with relatively faster NCMS expenditure growth, demonstrating worse PPR response. They were also associated with higher expenditure shifting to out-of-pocket expenditures (p>0.05). Post hoc analysis suggests that hospitals with surplus autonomy had higher OOP per admission (p<0.01), suggesting profiteering tendencies. Other dimensions of autonomy demonstrated imprecise association. Hospitals with more autonomy may not necessarily respond more effectively to PPRs that incentivise efficiency when they had previously been encouraged to maximise profit. Policymakers should assess the extent of perverse incentives before granting autonomy and adjust the incentives accordingly.

Analysis of the spatio-temporal variability and convergence of green development efficiency of city clusters in the middle reaches of the Yangtze River in China

The advantageous geographical location of the middle reaches of the Yangtze River (YRMR) plays an important role in promoting high-quality development in China and accelerating the development of the Yangtze River Economic Belt(YREB). In the new stage of development, green development efficiency (GDE) is an important metric for assessing the balance between economic development and ecological civilization. Therefore, taking three city clusters in China's YRMR as the study area, this research employs the Super-SBM model to assess their GDE in 2010–2020 in order to analyze the problem of GDE at the city scale. On this basis, spatio-temporal analyses, dynamic evolution, and convergence analyses have been carried out using the Thiel index, GML index model, and convergence model. The findings indicate that overall GDE has not yet reached an effective level and generally exhibits a two-stage fluctuating upward trend. Spatially, the pattern of distribution is "high in the southwest, low in the northeast". The differences within the city clusters in the YRMR in terms of green development are gradually narrowing, with differences within the same regions contributing the most to overall differences. The GML index shows a trend of fluctuating growth, indicating that the overall GDE growth is in good condition. GDE has grown significantly as a result of technological advancements, with the Wuhan metropolitan area (cluster A) experiencing the fastest growth in this regard, followed by the Chang-Zhu-Tan and the Poyang Lake rim city clusters (clusters B and C). The YRMR and its three major city clusters exhibit both σ- and β-convergence patterns. The convergence of GDE is simultaneously affected by several factors, including economic development (RGDP), urbanization level (UR), industrial structure (IND), technological development (TEC), and the level of openness (LO). Regional heterogeneity also exists. The above study provides decision-making references and empirical evidence for promoting green development in China's city clusters in the YRMR and advancing the improvement of economic-environmental incongruence in this area.

Low-cost deposition of tunable band gap Zn(O,S) as electron transport layer for crystalline silicon heterojunction solar cells

In recent years, the research on silicon heterojunction (HJT) solar cells based on dopant-free contacts has experienced rapid development. Zn(O,S) is a low work function n-type semiconductor compound with tunable band gap that can be used as the electron transport layer (ETL) in HJT solar cells. In our work, we choose Zn(O,S) as ETL and deposit it via the low-cost chemical bath deposition (CBD) method. Uniform and fast growth of Zn(O,S) films can be obtained by regulating the concentration of the complexing agent and the ratio of reactants to reduce the generation of impurities. To further achieve band matching with c-Si, the Zn(O,S) films are processed with air-annealing to modify the elemental ratios. The air-annealing lowers the interfacial electron transport barrier, which promotes charge separation and transport, thus reducing carrier recombination at the interface. Finally, the PCE of HJT solar cell based on CBD-Zn(O,S) ETL is close to 15 %, providing a new potential route for the development of low-cost HJT solar cells.

Circular Microstrip Patch Antenna : Design, Simulation, and Analysis For 5G Applications

Microstrip Patch Antennas (MPA) have emerged as a remarkable discovery in the period of miniaturization, despite the fact that advancements in antenna engineering have resulted in the fast growth of communication networks. This work encompasses the design, modelling, and analysis of circular microstrip patch antennas. The resonant frequency of the recommended patch antennas is 9 GHz, which is within the X band range. Ansys HFSS software was used to create them using Rogers RT/duroid 5880 material, which has a dielectric constant of 2.2. Five performance measures were utilized to examine the recommended MPAs: return loss, bandwidth, VSWR, gain, and HPBW. The required information refers to the measurements of return loss, voltage standing wave ratio (VSWR), and half power beamwidth (HPBW). The recommended antennas are ideal for use in radar, wireless, and satellite applications.

A lightweight distributed ELM-based security framework for the internet of vehicles

The fast growth of internet of vehicles (IoV) has created a new area of connectedness, with promising safety and efficiency in transportation. However, this advancement in vehicle technology has come with significant cybersecurity risks, specifically through control area network (CAN) protocol and other communication techniques within vehicles. This experimental study suggests a machine learning (ML) based security approach based on the extreme learning machine (ELM) algorithm to address these challenges. Unlike customary neural networks, ELM is known for its fast processing, minimal training time, and high accuracy, making it preferably suitable for dynamic IoV environments. The methodology involves data preprocessing, feature selection, and employing ELM for attack classification; the algorithm’s performance is evaluated using CARHacking, NSL-KDD, and EdgeIIoT datasets. We also examine the significance of distributed processing to enhance the computational efficiency of the model, obtaining 89% accuracy in 3 ms run-time for external networks, and 83% accuracy with 9 ms run-time for intra-vehical networks. This newly proposed security mechanism using ELM shows very accurate results in detecting intrusions with a high recall rate and reduced computation time through distributed processing.

Struggling with fish age, a comparison of otolith preparation techniques to unravel age and growth of boarfish, Capros aper (Linnaeus, 1758)

Fish age and growth data are crucial for understanding vital species’ traits and their populations. Boarfish is a pelagic species widely distributed in the Northeast Atlantic that is one of the most discarded non-commercial species on the Portuguese coast. Due to its potential valorisation as a new fishery in the Northeast Atlantic, boarfish has become object of interest in several published studies. However, since no age standard protocol has been implemented for boarfish, studies have used a variety of different otolith preparation techniques to estimate age, leading to contradicting and discrepant results. This research aims to consolidate biological insights into boarfish age and growth, lay the foundation for a standardized ageing protocol and serve as a benchmark study for the Portuguese west coast before commercial exploitation. Through the comparison of two otolith ageing methodologies, this study recommends using whole otoliths as the best method, revealing a maximum age of 15 years. The growth pattern estimated, indicated a biphasic growth pattern, with a faster initial growth rate that slows down at 2.4 years, the moment of change, when energy is allocated for sexual maturation. This finding was corroborated by a maturity ogive and analysis of fish size and otolith length relationship.

Integration of Conventional Breeding and Molecular Tools for Drought Tolerance in Maize: Review

Maize is an important staple crop for food, feed and industry globally. Despite the importance of maize as a principal food crop in developing country, drought is a major constraint that affects maize production, particularly in Sub-Saharan Africa where maize is grown under rainfed condition. Plant breeder has been striving to improve and develop drought tolerance crops. Nevertheless, these efforts still cannot meet the demand of food security due to fast population growth and climatic change. Secondary traits with associated to grain yield, advanced phenotyping, marker assisted selection/QTL, genomic wide association study and genomic selection methods are more expected to help for improvement of drought tolerance in maize. This article discussed the most secondary traits used for selection, plant physiological traits and crossing among drought tolerance elite lines and evaluation their segregants as well as hybrids performance under stress and optimum conditions. Emphasis also given to molecular dissection of drought tolerance complex trats using GWAS and /or gene discovery at hotspot regions for secondary traits, marker-assisted backcrossing and genome selection have been highlighted for increasing genetic gain in grain yield and predicating the breeding value for selection. Thus, further improvement is essential integration of conventional breeding and genomic tools for development of resilience maize varieties for drought tolerance in maize.

Opportunities and Challenges in the Synthesis of Noble Metal Nanoparticles via the Chemical Route in Microreactor Systems.

The process of noble metal nanoparticle synthesis is complex and consists of at least two steps: slow nucleation and fast autocatalytic growth. The kinetics of these two processes depends on the reductant "power" and the addition of stabilizers, as well as other factors (e.g., temperature, pH, ionic strength). Knowing these parameters, it is possible to synthesize materials with appropriate physicochemical properties, which can be simply adjusted by the type of the used metal, particle morphology and surface property. This, in turn, affects the possibility of their applications in various areas of life, including medicine, catalysis, engineering, fuel cells, etc. However, in some cases, the standard route, i.e., the chemical reduction of a metal precursor carried out in the batch reactor, is not sufficient due to problems with temperature control, properties of reagents, unstable or dangerous intermediates and products, etc. Therefore, in this review, we focused on an alternative approach to their chemical synthesis provided by microreactor systems. The use of microreactors for the synthesis of noble metal nanomaterials (e.g., Ag, Au, Pt, Pd), obtained by chemical reduction, is analyzed, taking into account investigations carried out in recent years. A particular emphasis is placed on the processes in which the use of microreactors removed the limitations associated with synthesis in a batch reactor. Moreover, the opportunities and challenges related to the synthesis of noble nanomaterials in the microreactor system are underlined. This review discusses the advantages as well as the problems of nanoparticle synthesis in microreactors.

Effect of Pinus halepensis Mill. Reforestation on the Above-Ground Biomass and Internode Elongation and Leaf Size of Native Species in Morroco

This study aims to determine the effect of the reforestation of Pinus halepensis Mill. on the above-ground biomass and morphological characteristics of native species (internode elongation and leaf size) in the Beni Sohane forest. Plant biomass of the herbaceous layer was harvested on randomly selected 2 m2 quadrats in reforested plots of ± 12, ± 25, and ± 45-year-old, and native forest controls. The internode length and leaf size (length and width) were measured on plants randomly selected belonging to four native species Quercus ilex L., Pistacia lentiscus L., Phillyrea angustifolia L., and Cistus creticus L.. The results showed that P. halepensis reforestation had no significant effect on the above-ground biomass and the leaves and internodes dimensions in the young plantations ± 12-year-old. However, as the pine trees mature, the average dry matter weight decreases, especially in stands 45 years old, where this weight was significantly lower than that of natural forests. This fact has led to herders abandoning important pastures previously used by their cattle. In addition, the fast growth of P. halepensis trees formed a canopy above all indigenous species resulting in changes in the dimensions of internodes and leaves. For the two oldest plantations, the internode length, leaf width, and length of the 4 species have been significantly increased. However, the leaf length-to-width ratio decreased significantly, with leaves in reforested plots being larger rather than longer compared to control samples in native forests. Planting P. halepensis can negatively impact the long-term growth of native plants, so we recommend periodically removing some of the pines (thinning) to restore the balance of these ecosystems. Thus, species selection for reforestation should consider maximizing rather than destroying ecological and socioeconomic services.

Effect of Pinus halepensis Mill. Reforestation on the Above-Ground Biomass and Internode Elongation and Leaf Size of Native Species in Morroco

This study aims to determine the effect of the reforestation of Pinus halepensis Mill. on the above-ground biomass and morphological characteristics of native species (internode elongation and leaf size) in the Beni Sohane forest. Plant biomass of the herbaceous layer was harvested on randomly selected 2 m2 quadrats in reforested plots of ± 12, ± 25, and ± 45-year-old, and native forest controls. The internode length and leaf size (length and width) were measured on plants randomly selected belonging to four native species Quercus ilex L., Pistacia lentiscus L., Phillyrea angustifolia L., and Cistus creticus L.. The results showed that P. halepensis reforestation had no significant effect on the above-ground biomass and the leaves and internodes dimensions in the young plantations ± 12-year-old. However, as the pine trees mature, the average dry matter weight decreases, especially in stands 45 years old, where this weight was significantly lower than that of natural forests. This fact has led to herders abandoning important pastures previously used by their cattle. In addition, the fast growth of P. halepensis trees formed a canopy above all indigenous species resulting in changes in the dimensions of internodes and leaves. For the two oldest plantations, the internode length, leaf width, and length of the 4 species have been significantly increased. However, the leaf length-to-width ratio decreased significantly, with leaves in reforested plots being larger rather than longer compared to control samples in native forests. Planting P. halepensis can negatively impact the long-term growth of native plants, so we recommend periodically removing some of the pines (thinning) to restore the balance of these ecosystems. Thus, species selection for reforestation should consider maximizing rather than destroying ecological and socioeconomic services.

Microstructure forming mechanism of inconel 625 alloy fabricated by laser/ultra-high (UHF) induction hybrid deposition method

To reveal the microstructure forming mechanism of laser/ultra-high frequency (UHF) induction deposition, this paper developed a microscopic phase-field (PF) model to numerically investigate dendrite growth during solidification. The macroscopic model of molten pool evolution is adopted to provide the solidification conditions for the microscopic PF model. The dendrite growth during laser deposition is simulated to evaluate the effect of UHF induction heat on the dendrite growth. Results show that because of the high temperature gradient and cooling rate, the PDAS of laser-UHF induction hybrid deposited layer is less than that of the laser deposited layer. The UHF induction heat also leads to a high flow velocity of the molten metal during laser-UHF induction hybrid deposition. The high flow velocity contributes to the decrease in PDAS by inhibiting the interdendritic enrichment of solute. During laser-UHF induction hybrid deposition, a higher solute gradient is present in the tip region of dendrite arm, leading to a faster dendrite growth rate. The UHF induction heat also increases the solute distribution coefficient during deposition, which further inhibits the element segregation. Under the action of UHF induction heat, a low interdendritic solute gradient and an evenly distributed solute can be obtained, thus helping increase interdendritic undercooling degrees and decreasing the PDAS. The simulated PDAS and solute distribution have good consistency with the experimental results. The spectral analysis of EDS line detection indicates that the laser-UHF induction hybrid deposited layer has a more refined microstructure and weaker element segregation than the laser deposited layer does.

Mapping high-resolution XCO2 concentrations in China from 2015 to 2020 based on spatiotemporal ensemble learning model

High-resolution column-averaged dry air mole fraction of CO2 (XCO2) data is crucial for understanding the spatiotemporal patterns of XCO2 and for mitigating carbon emissions. Due to the limited scanning range of sensors and strict inversion conditions, satellite-retrieved XCO2 data are often significantly incomplete. Machine learning models are widely used to fill these gaps in satellite XCO2 data. However, the limitations of individual machine learning models and the complexity of the spatial distribution of XCO₂ mean that the accuracy of XCO2 predictions still needs improvement. In this study, a new spatiotemporal stacked ensemble learning model (STEL) was developed by combining random forest (RF), extremely randomized trees (ERT), extreme gradient boosting (XGBoost), optical gradient boosting (LightGBM), and categorical boosting (CatBoost) using the stacking ensemble learning methodology. Considering the spatiotemporal heterogeneity of XCO2, a novel spatiotemporal weighting feature was constructed as part of the model's input parameters. Finally, the XCO2 observed by Orbiting Carbon Observatory 2 (OCO-2) was reconstructed using STEL, and a monthly mean XCO2 dataset covering China from 2015 to 2020 was generated at a spatial resolution of 0.1°. The results show that STEL exhibits superior performance and generalization capabilities compared to individual machine-learning models. R2 RMSE and MAPE were 0.9624, 1.0023 ppm, and 0.1583 % on the test set, and 0.8970, 1.4213 ppm, and 0.2475 % for R2, RMSE, and MAPE in ground validation, respectively. In 10-fold cross-validation, STEL's RMSE was reduced by 9.52 % compared to the best-performing single model (RF). The spatiotemporal trend of CO2 in China from 2015 to 2020 was analyzed using STEL XCO2 data. The results indicate that this dataset accurately reflects the spatiotemporal heterogeneity of XCO2 distribution at a fine scale. Overall, XCO2 exhibited a spatiotemporal pattern of “high in the east and low in the west” and “high in spring and low in summer.” Except in summer, high XCO₂ values were mainly distributed in the North China Plain. XCO2 trends and hotspots showed considerable spatial variation. The Pearl River Delta and Yangtze River Delta urban agglomerations have the fastest XCO2 growth rates, and the distribution of XCO2 hotspots is consistent with the distribution of population and economic centers. In the sparsely populated northwest of China, XCO2 is growing rapidly due to increased thermal power generation and coal mining. XCO2 hotspots in Northwest China are mainly located in Xinjiang, Ningxia, and Inner Mongolia. The methodology and data presented are useful for further research on carbon emissions, carbon sinks, and climate change.

Sex-specific differences in the growth and population characteristics of Sand crab Ovalipes punctatus (De Haan, 1833) in coastal waters of Korea

The sex-specific differences in the growth and population characteristics of the high-commercial-value sand crab Ovalipes punctatus were investigated in Korea. The estimated allometric growth between the sexes showed significant differences in all morphometric measurements. In the classification of growth types, carapace width-chela length exhibited positive and negative allometric growth in males and females, respectively. Carapace width-abdominal width showed positive relative growth in both sexes, and orbital spine width exhibited negative relative growth in both sexes. Consequently, sexual dimorphism was evident in all measured traits. Growth parameters estimated using the ELEFAN function of the FiSAT II program indicated higher values in males compared to females. Asymptotic length (CW∞) for males was estimated at 139.2 mm, whereas for females it was 116.6 mm. Additionally, the growth coefficient (K) was higher in males (0.65) than in females (0.54), suggesting faster growth in males. The winter point (WP) was 1 for males and 0.7 for females, indicating slower growth in males during the colder December and slower growth in females during the spawning period in August. The modified von Bertalanffy growth curves indicated asymptotic growth in all sexes, and the growth performance index (φ') showed higher values in males (4.10) compared to females (3.87), reflecting differences in growth curves. The steady increase in recruitment rates from July to September was associated with the appearance of larvae and their subsequent growth into juveniles, leading to their recruitment into the population during this period. Therefore, O. punctatus exhibited sex-specific differences in growth parameters, suggesting distinct growth strategies between the sexes.

Microstructural characterization of Stellite 6 alloy processed by electron beam melting

Stellite 6 alloy was subjected to electron beam melting (EBM) processing in this study. The main phases in the alloy are α-Co, ε-Co, M23C6 (M = Cr, Co, W, etc.), and M7C3 (M = Cr, Co, W, etc.) carbides. The microstructure of the EBM-processed Stellite 6 alloy comprises grains of relatively uniform sizes, with an average grain size of 11.1 μm. There is a relatively minor internal strain within the alloy. The majority of grains exhibit low intragranular misorientations, approximately around 0.5°, while a minority of grains display relatively larger intragranular misorientations, around 2.8°. The dominant {100} texture was developed in the build direction because of the fast growth of the <100> direction for a cubic crystal structure during solidification. The vertically aligned columnar grains contribute to the development of the <100> texture along the build direction. The elongated direction of columnar grains was parallel to the temperature gradient direction. This competitive growth direction at the solid-liquid interface results in slight tilts in the pole figures. The eutectic carbide phases are uniformly distributed along the grain boundaries. The cube–cube orientation relationships between the matrix and M23C6 carbide phase were identified as [001]α//[111]M23C6. The low stacking fault energy of the Stellite 6 alloy resulted in the formation of a high density of stacking faults within the grains. The interactions between stacking faults of different orientations were observed. Primary M7C3 carbides were found to transform into secondary M23C6 carbides, with a phase transition process observed where secondary carbides M23C6 surrounded primary carbides M7C3.

Use of Engineering-Educational-Empowerment Model to Improve the Integrated Traffic Impact Analysis and Environment Impact Analysis Results

In order to control road carriage way capacity and/or road environment degradation due to transport activities, the Traffic Impact Analysis TIA document has been directed to be integrated within the Environment Impact Analysis EIA document. However, only medium and high trip attractiveness was considered. Consequently, cumulative impact due to dense small scale concentrated in a certain corridor not only decrease road capacity but also increase road environment degradation. These unintended situations, especially at fast growth corridors, was recorded, including the parking index, on-street parking impacts due to inadequacy in existing parking space capacity. This activity aims to socialized and discussed the technical and environmental impacts due to on-street parking in order to improve better knowledge and transport policy decision. Therefore, an integrated approaches - using a Focus Group Discussion - based on engineering, educational and empowerment method was undertaken to identify a change in stake holder’s perception towards the correlation between transport and land use. It was found that, although within low trip attractiveness level category, but a dense small scale of activities produces great roadside friction and contribute negative impact on roadway capacity and air pollutant essence. This strongly indicate that a micro zoning regulation is required to control the type, number, scale and dense of social-economic activities, particularly in fast growth corridors.

Measuring Elementary Student Reading Gain in the Context of School-Implemented Multitiered Systems of Support

There is limited research with mixed results about student reading gains in Grades 1 to 5 within typical school-implemented Response to Intervention (RTI). As part of a larger study, we used school-administered screening data on a widely used computer-adaptive test (Measures of Academic Progress) to describe reading gains across one academic year. We observed relatively faster growth in the first grade than in the later grades. We found stronger growth for students not identified with a disability relative to students with low or high-incidence disabilities or a 504 plan. We explored moderation of gains for students receiving tiered interventions based on administrators’ interviews about RTI implementation. We observed that better ratings of administrators’ articulation about using the evidence-aligned RTI components of progress monitoring, data-based decision-making, and Tier 2 interventions were related to greater gains for students receiving Tier 2 or 3 intervention. We discuss implications, limitations, and directions for future research.

Aqueous co-solvent synthesis of Zeolitic Imidazolate Frameworks: The impact of co-solvents in the crystal growth kinetics

Zeolitic Imidazolate Frameworks (ZIFs) have been widely studied in recent decades in a variety of applications. However, a fundamental understanding of crystal growth kinetics as well as their formation mechanisms has been very limited. Underpinning such mechanisms might be of key importance for the predictable synthesis of ZIFs to rationally tune the structural and morphological properties for respective applications. Herein, the crystal growth kinetics and structural evolution of ZIF-8 crystals in various aqueous co-solvent reaction environments were studied with respect to synthesis time. By tracking the nucleation, crystal growth, stabilization and ripening, three potential kinetic formation mechanisms were proposed. More specifically, with methanol, isopropanol and acetone, a fast nucleation rate and crystal growth occurred within 60 minutes (min) at room temperature. However, ethanol and n-propanol showed prolonged nucleation which resulted in the slow formation of ZIF-L/ZIF-8 mixed phases at the early stage. Phase transformation to pure ZIF-8 was observed in longer syntheses. Nitrogen-containing solvent, N, N–dimethyl formaldehyde (DMF), was found to induce both nucleation and growth, resulting in large crystals in less than 60 min of fabrication. In each case, the crystal formation follows Avrami's classical model. Hence, by understanding the effects of co-solvents in ZIF nucleation, crystallization and phase selection, one can rationally design the crystals with predictable crystallinity, size, morphology, purity and surface properties for targeted applications such as adsorption of small molecules from aqueous mixtures.

On a new species of ostracod from the Brazilian Amazon and its potential for experimental studies in laboratory culture

Ostracods are taxonomically and ecologically diverse small crustaceans that have recently gained prominence in laboratory studies and environmental impact assessment. In this context, the present study aims to assess the applicability of a new freshwater ostracod for experimental studies in the laboratory, and we provide the formal description of Strandesia rondoniensisn. sp. The original specimens for setting the laboratory cultures originated from the Natural Park of Porto Velho, in the Amazon region (Rondônia State, Brazil). The growth and reproductive rates of eleven adult individuals of S. rondoniensisn. sp. were analyzed. The results showed a high morphological resemblance with Neostrandesia striata and Bradleytriebella lineata, even though the new species belongs to Strandesia, indicating evolutionary convergence. The life cycle analysis showed that individuals of S. rondoniensisn. sp. have fast growth and high reproductive rates, which favour their use in laboratory studies. Besides contributing to the knowledge about ostracods in the Amazon region, which has been poorly studied, the life cycle experiment characterizations provided here should promote the use of this new species as a model organism for laboratory studies.

Evaluation of Tilapia (Oreochromis niloticus) Survival and Growth in Aquaculture Systems with Different Feed Types

Proper feeding is crucial for promoting fast and healthy growth in fish, contributing to increased overall production. However, access to high-nutritional feed is not always feasible. Utilizing locally available ingredients presents a potential solution to this challenge. Consequently, this research aims to assess the impact of locally available feed ingredients on the growth and production of tilapia (O. niloticus) in Liberia. Three types of fish feed were prepared, namely Africa Rice fish feed (diet 1), soybeans fish feed (diet 2), and Gbarnga fish feed (control), each with distinct compositions. These feeds were evaluated to determine their effects on the growth and production performance of tilapia fish for the duration of 31 weeks. Fifty fish with an initial body weight of 12 g each were stocked in each hapa net. Data on survival rate (%), feed conversion ratio (FCR), and growth (g) were collected and compared. The growth results revealed a statistically significant difference (P &lt; 0.001) among the three selected fish feed types. Diet 1 exhibited a higher average mean weight of 1521.67 g per 92 fish followed by the control with an average mean weight of 1315.56 g per 88 fish, while diet 2 demonstrated comparatively lower growth, 1164.44 g per 96 fish. Survival rate and FCR, however, exhibited no significant differences. Notably, the cost of food supplies, particularly proteins, may constrain farmers' access to feed processing and formulation technology. Consequently, the findings of this study are expected to address challenges related to feed formulation and processing, providing valuable insights for the enhancement of fish farming practices.

Effect of polyoxyethylene laurate series surfactants on HCFC-141b hydrate formation

To address the problems of slow crystallization and nucleation in two-phase miscibility in the application of refrigerant hydrates, adding surfactants can be taken as an effective way to promote hydrate formation. Three kinds of polyoxyethylene laurate (LAE) surfactant with different hydrophilic chain lengths (LAE-4, LAE-9 and LAE-24) were selected as accelerators to study their effects on hydrate formation. LAE series surfactants significantly reduce hydrate nucleation induction time. The hydrate induction time of the system with 4.0 wt% LAE-9 is shortest (98 min). The hydrate formation with 4.0 wt% LAE-9 has small randomness and is more stable. Micelles formed by LAE surfactants provide more nucleation sites and accelerate hydrate growth. The hydrate cold storage density is related to the hydrophilic chain length of surfactant. The system with 4.0 wt% LAE-9, which has a suitable hydrophilic chain length, achieves the largest hydrate cold storage density (246.10 kJ·kg−1). Hydrate has the fastest growth rate of 4.80 kJ·kg−1·min−1 in the system with 2.0 wt% LAE-24. There is a “memory” effect during hydrate formation and dissociation cycle, eliminating the need for induction time during hydrate re-formation. Hydrate can be re-formed quickly.