Histological digestive tract of milkfish’s (Chanos chanos Forskal.) from District Ujung Pangkah, Gresik

Milkfish is a commodity with a high production rate. From the milkfish commodity, Gresik is the center of fishery production in East Java. Milkfish belongs to the herbivore group with the type of food from the plant group. Milkfish cultivation in traditional ponds still uses natural food as the main food for the cultivated commodities. Fish food affects the structure of the digestive tract, especially the intestines of fish. herbivorous fish have very long intestines even many times the body length, compared to omnivorous and carnivorous fish. Thus, this study aims to find out more clearly about the structure of the milkfish gut tissue. The digestive tract is related to the process of digestion, absorption and disposal of food waste, so it has an important role in the growth of fish. The research method used was descriptive experimental by making preparations of fish intestinal tissue and staining with Hematoxylin Eosin. The intestines of the fish observed were the front, middle and back. Observation of the preparations using a microscope with a dot slide scan photo. From the results of the study obtained an overview of the intestinal tissue structure of the upper (proximal), middle (middle) and lower (distal) fish. The structure of the front, middle and back of the milkfish gut tissue is similar, the difference lies in the number and thickness of the villi.

Integrity Evaluation and Management in High Temperature High Pressure and High Production Rate Wells in Southwest China

The Longwangmiao (referred to as LM) gas field in southwest China has characteristics of high temperature (144~156 °C), high pressure(75~76 MPa), and high production rate (70~100×104 m3/d). Serious well integrity problems were encountered in the development process; 21% of 56 wells were subjected to sustained casing pressure (SCP)(≥20 MPa). Downhole leak detection logs indicated the main cause was tubing connection leakage at a depth range of 0~2400 m. Wellhead growth was present in 33 wells and 4 wells exhibited gas leakage through wellhead valves. Theoretical analysis and field tests were conducted to investigate and manage well integrity problems. A method to calculate the allowable pressure for different annuli was proposed based on string strength analysis, and downhole leak detection was conducted using ultrasonic leak detection method. A multi-string mechanical model to predict wellhead growth was established and the threshold values were calculated under different gas rates. According to the structure of wellhead, a method based on ultrasonic phased array to detect the work state of the wellhead was adopted, which measured the actual thickness of key valves to evaluate service life. For wells with SCP, the allowable pressure for different annuli was calculated and the pressure management charts were drawn and all wells were in steady production. Downhole leak detection showed that SCP in the A annulus (annulus between the tubing and production casing) was caused by connection leakage of tubing. In newly completed wells, a premium connection was adopted based on tests under cyclic structural and environmental thermal loads that the connections may encounter at various production phases, and the total ratio of SCP in newly completed wells decreased by 31.4%. Wellhead growth was predicted and compared with actual data, which showed an increase in average accuracy of 20~30% compared to the results from the WellCAT software. Sensitivity analysis revealed that the length of un-cemented casing and the production rate were the critical factors affecting the wellhead growth. The valve leakage of FF level material wellhead was caused due to corrosion after the removal of the coating, and no leakage was detected in the HH level material wellhead. Thickness survey showed that the average reduction was 0.085 mm~0.23 mm for HH wellhead, and 1.12 mm~2.24 mm for FF wellhead.

Wet Spun PEDOT/CNT Composite Hollow Fibers as Flexible Electrodes for H2O2 Production

The electrochemical synthesis of hydrogen peroxide (H2O2) using the oxygen reduction reaction (ORR) requires highly catalytic active, selective, and stable electrode materials to realize a green and efficient process. The present publication shows for the first time the application of a facile one-step bottom-up wet-spinning approach for the continuous fabrication of stable and flexible tubular poly(3,4-ethylene dioxythiophene) (PEDOT : PSS) and PEDOT : PSS/carbon nanotube (CNT) hollow fibers. Additionally, electrochemical experiments reveal the catalytic activity of acid-treated PEDOT : PSS and its composites in the ORR forming hydrogen peroxide for the first time. Under optimized conditions, the composite electrodes with 40 wt % CNT loading could achieve a high production rate of 0.01 mg/min/cm2 and a current efficiency of up to 54 %. In addition to the high production rate, the composite hollow fiber has proven its long-term stability with 95 % current retention after 20 h of hydrogen peroxide production.

Response of Three Sweet Maize Varieties to Leaf Blight (Exserohilum turcicum) Planted in Freshwater Swamps of South Sumatra

Planting resistant varieties is the most effective control method and is recommended because it is safe for the environment. The problem to be raised in this study was the use of the same variety of maize in every growing season by farmers. The use of one of these varieties could cause a decrease in yield due to the resistance of the variety to certain pests and diseases. This study aimed to provide information in the form of the use of sweet maize varieties resistant to leaf blight and potential to be planted in the swampy lowland of South Sumatra. The varieties used in this study were Bonanza F1, MB-01 Sweet and Love Sweet varieties. Based on the results of the study, as a whole the use of several varieties had a significant effect on the severity of leaf blight. The results of this study showed that there were differences in the response to resistance of each variety to leaf blight caused by the fungus Exserohilum turcicum. The observation of disease severity was carried out only in the vegetative phase. The highest disease severity was found in the Bonanza, Love Sweet, and MB-01 Sweet varieties at 16.90%, 9.99% and 7.07% respectively. The production data showed that there was no significant effect on the leaf blight. The MB-01 Sweet variety had the potential to be planted on swampy soil because it had resistance to blight and had a high production rate.

On Modelling Parasitic Solidification Due to Heat Loss at Submerged Entry Nozzle Region of Continuous Casting Mold

Continuous casting (CC) is one of the most important processes of steel production; it features a high production rate and close to the net shape. The quality improvement of final CC products is an important goal of scientific research. One of the defining issues of this goal is the stability of the casting process. The clogging of submerged entry nozzles (SENs) typically results in asymmetric mold flow, uneven solidification, meniscus fluctuations, and possible slag entrapment. Analyses of retained SENs have evidenced the solidification of entrapped melt inside clog material. The experimental study of these phenomena has significant difficulties that make numerical simulation a perfect investigation tool. In the present study, verified 2D simulations were performed with an advanced multi-material model based on a newly presented single mesh approach for the liquid and solid regions. Implemented as an in-house code using the OpenFOAM finite volume method libraries, it aggregated the liquid melt flow, solidification of the steel, and heat transfer through the refractory SENs, copper mold plates, and the slag layer, including its convection. The introduced novel technique dynamically couples the momentum at the steel/slag interface without complex multi-phase interface tracking. The following scenarios were studied: (i) SEN with proper fiber insulation, (ii) partial damage of SEN insulation, and (iii) complete damage of SEN insulation. A uniform 12 mm clog layer with 45% entrapped liquid steel was additionally considered. The simulations showed that parasitic solidification occurred inside an SEN bore with partially or completely absent insulation. SEN clogging was found to promote the solidification of the entrapped melt; without SEN insulation, it could overgrow the clogged region. The jet flow was shown to be accelerated due to the combined effect of the clogging and parasitic solidification; simultaneously, the superheat transport was impaired inside the mold cavity.

Mathematical Programming Application in Sublevel Caving Production Scheduling

Production scheduling determines the most beneficial mining sequence over the life of a mine. Developing a schedule that meets all mining aspects can substantially reduce mining costs and increase profitability. Among all underground mining methods, the sublevel caving method is a common method with moderate development requirements, a high production rate, and a high degree of mechanization and flexibility. None of the manual planning methods and heuristic algorithms used in commercial software will lead to a truly optimal schedule. Mathematical programming models, particularly mixed-integer programming (MIP), have been applied to provide an operationally feasible multi-time-period schedule in sublevel caving. However, confined blasting conditions, chaotic material flow, and frequent mixing of ore and waste while loading broken ore at the drawpoint make the sublevel caving method unique when producing a holistic plan. This paper reviews all mathematical programming models presented in sublevel caving production scheduling, highlights the inherent characteristics of the sublevel caving that affect production, and puts forward some promising ideas for future works.

Search for low-mass leptoquarks using the llqq final states in Pb-Pb ultra-peripheral collisions

After a review over past experiments and theoretical requirements from low-energy flavour physics, we argue that the possibility of low-mass leptoquarks (LQ) cannot be fully excluded due to the assumptions made in the measurements. Therefore we propose to search for the pair production of low-mass leptoquarks in Pb-Pb ultra-peripheral collisions with the least model dependence (assuming a small coupling constant ≲ 0.1). There are a couple of advantages: 1) high photon flux provides high production rate for low mass LQs; 2) the background contamination is much lower than that in p-p collisions. The analysis strategy permits a leptoquark to decay to all possible lepton-plus-quark modes. Taking the scalar LQ, S3, with an electric charge $$ \left|q\right|=\frac{4}{3}e $$ q = 4 3 e , as example, the mass point of 100 GeV can be excluded at the 95% confidence level using a dataset of 4 pb−1 Pb-Pb ultra-peripheral collisions at $$ \sqrt{s} $$ s = 5.02 TeV and the performance of the ATLAS detector in Run 2. The proposed method also applies to searching for high-mass LQs in p-p collisions as long as the LQ pair production mechanism dominates.

Study on the Water Invasion and Its Effect on the Production from Multilayer Unconsolidated Sandstone Gas Reservoirs

Water invasion is a common occurrence in multilayer unconsolidated gas reservoirs, which results in excessive water production and reduces the economic life of gas wells. However, due to multiple layers, active edge water, and strong heterogeneity, the mechanism of water invasion and its effect in the unconsolidated sandstone gas reservoir require understanding in order to improve efficiency and minimize economic cost. In this study, an experimental study on edge water invasion of the multilayer commingled production in unconsolidated sandstone gas reservoirs was conducted to understand the water invasion process along with different permeability layers. The results show that the edge water invasion in the commingling production is mainly affected by two major factors including reservoir permeability and gas production rate, which jointly control the encroaching water advance path and speed. The nonuniform invade of edge water may occur easily and water prefers to invade toward the gas well along with high permeability layers when the commingling production is in the condition of large permeability gradient and high production rate. The bypass flow will occur when there are high permeability channels between the layers, which causes water blocking to low-permeability layers and periphery reservoirs far away from gas wells. The findings of this study can help for a better understanding of water invasion and the effects of reservoir properties so as to optimize extraction conditions and predict gas productivity in unconsolidated sandstone gas reservoirs.

Multi-Functional Core-Shell Nanofibers for Wound Healing

Core-shell nanofibers have great potential for bio-medical applications such as wound healing dressings where multiple drugs and growth factors are expected to be delivered at different healing phases. Compared to monoaxial nanofibers, core-shell nanofibers can control the drug release profile easier, providing sustainable and effective drugs and growth factors for wound healing. However, it is challenging to produce core-shell structured nanofibers with a high production rate at low energy consumption. Co-axial centrifugal spinning is an alternative method to address the above limitations to produce core-shell nanofibers effectively. In this study, a co-axial centrifugal spinning device was designed and assembled to produce core-shell nanofibers for controlling the release rate of ibuprofen and hEGF in inflammation and proliferation phases during the wound healing process. Core-shell structured nanofibers were confirmed by TEM. This work demonstrated that the co-axial centrifugal spinning is a high productivity process that can produce materials with a 3D environment mimicking natural tissue scaffold, and the specific drug can be loaded into different layers to control the drug release rate to improve the drug efficiency and promote wound healing.

Bubble Swelling in Ferritic/Martensitic Steels Exposed to Radiation Environment with High Production Rate of Helium

Reduced-activativon ferritic/martensitic (RAFM) steels are prospective structural materials for fission/fusion nuclear applications because their radiation and swelling resistance outperforms their austenitic counterparts. In radiation environments with a high production rate of helium, such as fusion or spallation applications, these materials suffer from non-negligible swelling due to the inhibited recombination between vacancy and interstitial-type defects. In this work, swelling in helium-implanted Eurofer 97 steel is investigated with a focus on helium production rates in a wide range of helium/dpa ratios. The results show virtually no swelling incubation period preceding a steady-state swelling of about 2 × 10−4%/He-appm/dpa. A saturation of swelling above 5000 He-appm/dpa was observed and attributed to helium bubbles becoming the dominant sinks for new vacancies and helium atoms. Despite a relatively low irradiation temperature (65 ± 5 °C) and a rather high concentration of helium, transmission electron microscope (TEM) results confirmed a microstructure typical of ferritic/martensitic steels exposed to radiation environments with high production rates of helium.