Water Tube Research Articles

Comparison of water-saving potential of fallow and crop change with high water-use winter-wheat – summer-maize rotation

A land fallow system (LFS) designed to adjust the winter-wheat summer-maize cropping system to fallow summer-maize was introduced in Hebei Province to alleviate groundwater depletion in the region. However, some of the water saved was lost through evaporation from bare soil and transpiration by weeds. So far, no measurement has been done in the region to address this non-productive water loss, thereby limiting the water-saving potential of the introduced LFS. Furthermore, the reduction in crop production under the summer-maize – fallow system threatens food security. The objective of this study was to determine which practice is effective to keep soil water during fallow and the exact water-saving potential of different cropping system in the region. Firstly, field experiments were conducted under various soil surface management systems — including plastic mulching (PM), straw mulching (SM), shallow tillage (ST) and weed control (WC). The effects of saving water, controlling weeds and managing nutrients were analyzed under the various surface soil management methods. The results showed that compared with the control (no soil surface management, CK), 177, 64.7, 71.0 and 25.0 mm of water was saved respectively under PM, SM, WC and ST surface soil management methods in 2019–2020. The effect of weed control decreased in the order of PM > WC > SM > ST. While PM significantly increased soil nutrient in all the treatments, the others showed slight but insignificant increases. Secondly, the precise water-use of each of the cropping systems was determined using large lysimeters. The analysis showed that compared with the wheat-maize system, 60–100 mm of water was saved under alternating wheat-soybean, wheat-millet, mung bean – fresh edible maize, spring sweet potato cropping systems. The results were key for technical guide in developing future cultivation adjustment policies.

Power Generation from Utilizing Thermal Energy of Hazardous Waste Incinerators

A large amount of thermal energy is generated from burning hazardous chemical wastes, and the temperature of the flue gases in hazardous waste incinerators reaches up to (1200 °C). The flue gases are cooled to (40°C) and are treated before emission. This thermal energy can be utilized to produce electrical power by designing a system suitable for dangerous flue gases in the future depending on the results of much research about using a proto-type small steam power plant that uses safe fuel to study and develop the electricity generation process with water tube boiler which is manufactured experimentally with theoretical development for some of its parts which are inefficient in experimental work. The studied system generates theoretically (120 kg steam /h at 8 bars) with dry wood as fuel and preheating for the air of combustion and feed water and a diesel engine of (8 hp) four-stroke with single piston converted to steam engine coupled with the electrical generator of (3 kVA). The results are compared with practical values valid in the literature about small power plants of steam capacity (0.1-1) ton/h and operating pressure up to 10 bars. Experimentally, the generated electrical power is little and sufficient to operate a small fan and lump. The current converted steam engine is better than a conventional steam engine in auto lubrication with some operational problems. The boiler efficiency is 63.28%.

Exploring low-carbon mulching strategies for maize and wheat on-farm: Spatial responses, factors and mitigation potential

Mulching strategies - including plastic film mulching (FM) and straw mulching (SM) - can enhance crop yields while affecting multiple greenhouse gas (GHG) fluxes. However, most of currently published site-based studies only focus on a certain gas, resulting in an inability to spatially integrated understanding of changes in agricultural global warming potential (GWP) and greenhouse gas intensity (GHGI) caused by mulching across China. Thus, we developed an optimal model considering crop type, meteorology, soil and management variables by four machine learning methods, namely support vector machine, multilayer perceptron, random forest, and gradient boosting machine (GBM). Then we mapped the relative changes in yield and GHG fluxes caused by mulching strategies. The GBM model had the best simulation capability for yield and GHGs in China. Our result showed that FM increased yield in maize (25 %) and wheat (19 %), while SM respectively increased by 14 % and 11 %. Among the relative changes due to mulching strategies, yield and N2O emissions were mainly influenced by soil fertility and soil properties, CH4 uptakes and CO2 emissions were more affected by environmental factors. GWP in maize and wheat average increased by 40 % under FM, while SM decreased GWP by 14 % and 2 %, respectively. Besides, FM average increased GHGI in maize and wheat by 17 % and 9 %, and SM decreased GHGI by 22 % and 12 %, respectively. Spatially, FM reduced maize GWP on 19 % of cropland, while SM reduced maize and wheat GWP on 71 % and 64 % of cropland, respectively. Soil pH was significantly correlated with ΔGHGI in maize and wheat. Our analysis not only estimated for the first time the spatial effects of mulching strategies across China, but also systematically analyzes the agricultural carbon emission mitigation potential of mulching strategies, which promote the development of low-carbon agriculture based on locally appropriate mulching strategies.

Interspecific Repellent Effect of Hydroalcoholic Solution of Nest Refuse from Two Leaf-cutter Ant Species

Leaf-cutting ants manage their waste continuously to avoid risks of colony contamination. The presence of residues or their odor near foraging areas is enough for ants to stop attacking plant tissues. However, to date, no study has demonstrated an interspecific effect of nest waste on the deterrence of leaf-cutting ants. Here, we tested whether a hydroalcoholic extract of nest refuse (NR) of the leaf-cutting ants Acromyrmex balzani Emery, 1890 and Atta opaciceps Borgmeier (Hymenoptera: Formicidae, Attini) causes an interspecific deterrent effect. Field colonies of Ac. balzani (n = 30) and A. opaciceps (n = 36) were used. For each colony, we offered baits made with plastic straws covered by citrus pulp and sprayed with a hydroalcoholic solution of 20% (vol/vol) alcohol/water (Control) or an extract of 20% (vol/vol) of NR from Ac. balzani and/or A. opaciceps. Over 20-30 minutes we recorded the amount of baits removed and data were compared through survival analysis and Linear Mixed Effect (LME) model. Ants avoided collecting baits sprayed with NR resulting in less than 20% of these baits being carried to the nest versus 80% of control baits. The deterrence was both intra and interspecific, considering that the response was similar for baits from both species. Such results reinforce the premise that the presence of nest refuse alters the foraging behavior of ants and paves the way for new studies that can verify its effectiveness in reducing foliar consumption on a larger spatial scale.

Analysis of The Application of Ultraviolet Water Sterilizer in Maintaining The Quality of Drinking Water on The MV. EPIC PAN

Ultraviolet water sterilizer is a long cylindrical device used for the sterilization of water into drinkable water. Ultraviolet water sterilizer has two main parts: an adapter and UV tubes. The adapter serves to drain the ratio of electricity according to the voltage and current required by ultraviolet water sterilizer. UV tubes contain ultraviolet lamps where light is the main equipment for making the water drinkable and the water will flow along with the ultraviolet rays, so that the water flowing in the tube is passed through the sterilization process with ultraviolet rays so that the water is unfit for consumption. The problems that the authors take in this study are the factors that affect the declining quality of sterilization, the impact of what happens when the quality of sterilization decreases, and what efforts are made to keep the quality of sterilization is not decreased. The data was collected through observations, interviews, and literature directly related to the subject related to the factors, the impact, as well as the efforts of the decline in the sterilization process to the sterilizer in order to improve the quality of drinking water. The cause of the decline to the sterilization process in order to improve the quality of drinking water in MV. PAN EPIC that dirty filters, dirty water tubes, and the dirty ultraviolet lamp or resulting in less fresh water, complaints against the company, as well as the ship's operational costs are reduced. Therefore some efforts are made to improve the quality of the results of sterilization including cleaning filters, cleaning water tubes, and also cleaning the germicidal lamp,

Multisite MRI Intravoxel Incoherent Motion Repeatability and Reproducibility across 3 T Scanners in a Breast Diffusion Phantom: A BReast Intravoxel Incoherent Motion Multisite (BRIMM) Study.

Monoexponential apparent diffusion coefficient (ADC) and biexponential intravoxel incoherent motion (IVIM) analysis of diffusion-weighted imaging is helpful in the characterization of breast tumors. However, repeatability/reproducibility studies across scanners and across sites are scarce. To evaluate the repeatability and reproducibility of ADC and IVIM parameters (tissue diffusivity (Dt), perfusion fraction (Fp) and pseudo-diffusion (Dp)) within and across sites employing MRI scanners from different vendors utilizing 16-channel breast array coils in a breast diffusion phantom. Phantom repeatability. A breast phantom containing tubes of different polyvinylpyrrolidone (PVP) concentrations, water, fat, and sponge flow chambers, together with an MR-compatible liquid crystal (LC) thermometer. Bipolar gradient twice-refocused spin echo sequence and monopolar gradient single spin echo sequence at 3 T. Studies were performed twice in each of two scanners, located at different sites, on each of 2 days, resulting in four studies per scanner. ADCs of the PVP and water were normalized to the vendor-provided calibrated values at the temperature indicated by the LC thermometer for repeatability/reproducibility comparisons. ADC and IVIM repeatability and reproducibility within and across sites were estimated via the within-system coefficient of variation (wCV). Pearson correlation coefficient (r) was also computed between IVIM metrics and flow speed. A P value <0.05 was considered statistically significant. ADC and Dt demonstrated excellent repeatability (<2%; <3%, respectively) and reproducibility (both <5%) at the two sites. Fp and Dp exhibited good repeatability (mean of two sites 3.67% and 5.59%, respectively) and moderate reproducibility (mean of two sites 15.96% and 13.3%, respectively). The mean intersite reproducibility (%) of Fp/Dp/Dt was 50.96/13.68/5.59, respectively. Fp and Dt demonstrated high correlations with flow speed while Dp showed lower correlations. Fp correlations with flow speed were significant at both sites. IVIM reproducibility results were promising and similar to ADC, particularly for Dt. The results were reproducible within both sites, and a progressive trend toward reproducibility across sites except for Fp. 2 TECHNICAL EFFICACY: Stage 1.

Performance Evaluation and Parametric Optimization of Coal-Fired Water Tube Boiler Using the Grey-Taguchi Method

Industries, district heating companies, and public institutions that use boilers for heating, processing, or power production find it challenging to run at peak efficiencies due to rising fuel prices. Insufficient heat energy production and distribution through boilers contribute to an overall increase in energy expenditure. The performance of a boiler is affected by various controlling parameters, including specific fuel consumption capacity, load, and heat losses. The current study was conducted to evaluate the performance of the coal-fired water tube boiler at D.G. Khan Cement Company Limited, Pakistan. The experimental results were validated with artificial neural network- (ANN-) based predictions, which were observed to have an error of 14% in the regression plot. In this study, the performance parameters of the boiler, including steam temperature (ST), steam pressure (SP), and specific steam flow rate (SSFR), were optimized against fuel consumption (FC) and load using the Grey-Taguchi method. The best-performing parameters, with the best criteria, were observed at an overall grey relational grade (OGRG) of 0.891 and a load of 66%. The findings indicated that the overall performance of the boiler was optimized with an FC of 3.09 kg/s, a load of 66%, ST of 532°C, SP of 9.93 MPa, and SSFR of 21.38 kg/s.

The role of normal force on the fretting corrosion behaviour of alloy 690 TT tube against 410 stainless steel plate in high temperature high pressure water

The effect of normal force on fretting corrosion of Alloy 690 TT tube in high temperature high pressure water was investigated. Increasing the normal force accelerates the wear behaviour of the tube. The small normal force has a larger coefficient of friction. The wear mechanism changes from the dominant form of abrasive wear to delamination wear. The increase in normal force not only causes the wear debris layer (WDL) and the tribologically transformed structure to become thicker and more refined, but also affects the oxidation and corrosion behaviour of the tube and changes the composition of the WDL.

Long-term straw mulch underpins crop yield and improves soil quality more efficiently than plastic mulch in different maize and wheat systems

Field mulching efficiently increases crop production, yet the feasibilities of plastic mulch (PM) and straw mulch (SM) in different ecological regions are scarcely documented. This study aimed to investigate yield responses and soil quality changes following PM and SM, thereby identifying their suitability in different maize and wheat systems. A total of 202 peer-reviewed publications after 2000 that involved field experiments treated with no-mulch, PM, and SM were collected, and yield ratio of PM to SM (RPM/SM) was calculated to quantitatively understand their mulching efficacy. PM significantly increased grain yields in mono rather than double-cropping systems relative to SM, with an averaged RPM/SM at 1.28 in mono-maize, 1.11 in mono-wheat, and 1.05 for maize and 1.04 for wheat in double-cropping systems. Growing-season precipitation was significantly correlated with RPM/SM across mono and double-cropping systems, showing an RPM/SM of 1 at 530-mm for wheat in mono-cropping and 395-mm in double-cropping, and a stabilized RPM/SM observed at 1.082 in mono-cropping and 1.001 in double-cropping for maize, when growing-season precipitation exceeded 576-mm and 500-mm, respectively. Long-term field experiments illustrated significant relationships between RPM/SM and experimental duration, showing an RPM/SM of 1 at the 10.3-year for mono-maize, and 14.6-year for maize and 16.7-year for wheat in double-cropping, and a stabilized RPM/SM of 1.075 when trial time exceeded 3.7 years for mono-wheat, indicating a logged better performance of agronomic yield for SM. Owing to remarkable increases of soil organic C (SOC), total N, available K, and microbial biomass C, SM received the highest soil quality index across mono- and double-cropping systems, compared with PM and no-mulch. Growing-season precipitation, soil moisture at the sowing stage, SOC, and total N are the vital climatic and physicochemical variables mediating RPM/SM regardless of mono and double-cropping systems. Long-term SM rather than PM is an alternative for addressing the triple challenges of food security, soil degradation, and environmental mitigation. Quantifying the mulching efficacy on crop yields in different maize and wheat systems contributes to underpinning soil fertility and productivity in water-limited areas.

An Innovative Alternative to Plastic Straws with Bacterial Cellulose

This study aims to introduce the usage of biodegradable bacterial cellulose as an alternative material to straw production. Cellulose is a crystalline linear chain polysaccharide found in various organisms with cell walls. Known for its strength and durability, cellulose is also biodegradable due to its organic nature. Through a series of different experiments that include the production of cellulose from SCOBY (symbiotic culture of bacteria and yeast) and the subsequent creation of straws from the cellulose and food-safe glue, this study proposes a more environmentally friendly alternative to plastic straws. Further experiments were done to compare the functionality of the cellulose straw to that of plastic straws and other alternatives currently in the market, including paper and metal straws. This was done using a strength test to see how much weight the straws could hold before breaking, a test to see how long the straws could maintain their integrity with water running through them, and an experiment where different drinking liquids were used. It was found that the cellulose straws displayed no loss in functionality when compared to the other straws and displayed similar levels of durability as the plastic straws.

Polylactide/cellulose pulp composite paper with laminate structure via polylactide ultrafine fiber for eco-friendly straw

Paper straws with environmental friendliness have been widely used to replace plastic straws, but their poor mechanical properties and uncontrollable deformation bring an unsatisfactory experience for users. Herein, we developed a polylactic acid/cellulose fiber (PLA/CF) ultrafine-fiber paper with a sandwich‐like structure via wet papermaking and laminated hot pressing, employing PLA ultrafine fiber and CF as raw materials. The PLA/CF ultrafine fiber paper has remarkable mechanical properties due to the tangling of the fibers and the strong hydrogen bonding that occurs between the PLA and CF during hot pressing. The test results demonstrate that the tensile strength of PLA/CFs ultrafine fiber paper can reach 60.32 N/cm, and it still retains great wet strength (27 N/cm) and stiffness (117.7 mN·cm) after long-time service in various clod and hot liquids. Besides, PLA/CF ultrafine fiber paper also displays high biodegradability, with a degradation rate of 70% after being buried in soil for 120 days. We believe that PLA/CF ultra-fine fiber paper with excellent comprehensive performance can be expected to completely replace plastic straws.

Memanfaatkan Limbah Sedotan Plastik Menjadi Vas Bunga Hias

This journal is being kept to learn more about the process of making flower pots out of plastic straws. A qualitative descriptive research method is employed with this kind of literature review investigation. The findings demonstrated that recycling plastic garbage into flower pots is a step toward reducing plastic waste, as it is well known that plastic waste cannot degrade naturally. Making flower pots out of plastic garbage has a variety of purposes, including: By employing plastic trash as a primary component of flower pots, which can be reused and does not end up as waste in the environment, it is possible to reduce the amount of plastic waste in the environment.&#x0D; Keywords: Waste Plastic Straws, Flower Pots

Effect of Paddy Straw Incorporation on Growth and Yield of Rice under Wetland Ecosystem

Burning the paddy straw had variety of effects both on and off the farm. It entails nutrient and economic productivity loss in addition to impact on air quality, animal and human health. Soil incorporation is a cost-effective method of disposing the paddy straw. Effects of enhanced paddy straw incorporation in the field to investigate the growth and yield parameters during the summer season at TNAU, Coimbatore. The treatments comprise Continuous flooding (Conventional) (M1), AWDI (field water tube): Irrigation at soil moisture depletion by 10 cm (M2), AWDI (field water tube): Irrigation at soil moisture depletion by 15 cm (M3) as main plots. The subplot treatments consist of Rice raw straw incorporation + 75% RDF (S1), Rice raw straw incorporation with Pusa Decomposer Capsules + 75% RDF (S2), Rice raw straw incorporation with TNAU Bio mineralizer + 75% RDF (S3), Rice raw straw incorporation with Pusa Decomposer Capsules + TNAU Bio mineralizer + 75% RDF (S4), 75% RDF (S5), 100% RDF (S6). Incorporation of rice straw, Pusa decomposer, TNAU Bio-mineralizer along with 75% RDF recorded better results in all growth stages and yield.

Effects of organic and inorganic mulching, nettle extract, and manual weeding on weed management under direct-seeded lentil in Meknes region, Morocco

Weeds represent a major problem for the production of food legumes in Morocco. In order to cover its legume needs, the country currently imports this commodity, particularly lentils (Lens culinaris Medik.). The present study was conducted to investigate the effects of some agroecological strategies, such as manual weeding, fermented nettle extract (Urtica dioica L.), black plastic, and wheat straw mulching, on weed management, yield and yield components of lentil. The experiment was carried out at the Agroecology and Environment platform of the National School of Agriculture in Meknes, Morocco, in 2020–21 and 2021–22. Five treatments were tested in a complete randomized block design with four replications. The data analysis revealed that crop competition with weeds can result in a yield loss of over 60%. The weed flora identified was very diverse, with 27 different species. All treatments resulted in effective weed management compared to the control (untreated), significant economic gains and a difference in protein content, and a significant decrease in weed density and dry biomass by more than 50% at the flowering and maturity stages. The nettle extract treatment was less effective than the other treatments, but did not show phytotoxic effects on the crop, and it inhibited the germination of more than 50% of Glebionis coronaria (L.) seeds and more than 80% of Avena stirilis (L.) seeds compared to the control under laboratory conditions, which was confirmed in the field. The agroecological practices tested in this study resulted in the highest yield and yield components of the lentil crop compared to the control, leading us to conclude that reducing weed infestation is useful in cropping systems where chemical or mechanical weed control is not feasible, and for crops with low weed competitive ability.

Identification and expression of cysteine sulfite decarboxylase genes and their response to hyposalinity stress in Ruditapes philippinarum

Cysteine sulfinate decarboxylase (CSAD) is a rate-limiting enzyme in taurine biosynthesis. In this study, the structure and expression characteristics of the RpCSAD gene in Ruditapes philippinarum were analyzed. The pyridoxal phosphate (PLP)-dependent amino acid carboxylase structural domains and catalytic active sites of six copies of RpCSAD were highly conserved. Tissue expression analysis demonstrated that RpCSAD1 and RpCSAD3-6 was primarily expressed in the mantle tissue, and RpCSAD2 in the water tube and gonad tissue. After exposure to hyposalinity stress, the expression levels of RpCSADs were found to be upregulated in all three shell-colored groups of clams. Remarkably, there was a pronounced increase in the expression of RpCSAD1-6 observed specifically in the zebra shell-color groups. These findings strongly suggest the involvement of taurine metabolism in the response of zebra shell-color clams to low salinity stress, thereby emphasizing its critical role in the adaptation mechanisms. These findings could contribute to a better understanding the mechanisms of osmotic stress tolerance in shellfish.

Bio-based alternatives to plastic drinking straws: are they more environmentally benign and consumer preferred?

The global production of nondegradable catering straws has skyrocketed due to their versatile properties, which results in significant CO2 emissions and pollution of the ecological system. While paper and polylactic acid straws have gained increasing popularity in the beverage industry, there needs to be more investigation of the vital product properties determining their hedonic differences. This study systematically compared the properties of paper, polylactic acid and plastic straws, and their impacts on the consumer experience and willingness. Results showed that the open structure of paper straws prompted water penetration and absorption, reaching a water absorption of 30% after 10-min wetting, which might affect the taste of the drink. In contrast, the compact polymer matrices of polylactic acid straws prevented mass exchange in their use for drinking but retarded product biodegradation under natural conditions. Results of consumer testing showed that while the participants had a comparable liking of paper and polylactic acid straws to insert into a drink (i.e., 4.16 and 4.47 out of 5, respectively), the intrinsic difference was covered up by the open-ended capping for beverages. For the “fully sealed on top” dataset, paper straws dropped to 3.46, while that for polylactic acid straws remained at 4.70. Furthermore, a biodegradable straw easily inserted into a drink without fracture may positively prompt merchants’ revenue. This study is expected to pave the way for the advancement and widespread use of bio-based products.Graphical

Biocomposites of rice straw paper with chitosan: hydrophobicity and mechanical properties

Biocomposites of rice straw paper with chitosan: hydrophobicity and mechanical properties

Peningkatan Kreativitas Masyarakat dalam Mengolah Limbah Sedotan Plastik Menjadi Tempat Tissue

The use of plastic straws to make tissue box crafts that are worth selling. The purpose of the student creativity program - entrepreneurship (PKM-K) is to motivate students to become entrepreneurs in processing waste, especially into crafts that have market value, such as tissue box crafts. Plastic straw waste in the Palopo City environment is one of the elements that causes pollution which is not easy to decompose because it is made from plastic and is inorganic. Utilizing plastic straw waste into valuable products is a creative effort to reuse waste to preserve the environment and increase the economic value of waste that is no longer used. The methods used are the input, process (production), output and evaluation stages. The results of this program are input, conducting market surveys to determine market conditions. Next is a feasibility study of the business to be run. The last stage is the selection of materials and the provision of places as well as facilities and infrastructure to support the production process. Process (production), the process of making a tissue box starts from the preparation of materials and tools. Output, namely the craft of tissue holders that are ready to be used and marketed to consumers. The last is evaluation. At this stage, we will review any deficiencies that make consumers uncomfortable using our products. The conclusion of the PKM-K program is that the use of plastic straws to make tissue box crafts that are worth selling can provide skills to students, especially at the Muhammadiyah University of Palopo, to remain innovative and creative in processing plastic straw waste, providing opportunities for students to practice entrepreneurship with a comprehensive understanding of the concept of entrepreneurship, and build students' enthusiasm to stay in business.

Eucheumatoid seaweed farming in the southern Philippines

Eucheumatoid seaweed farming (ESF) is an important enterprise that provides livelihood opportunities for tropical coastal communities. In this work, we surveyed the current practices of ESF in Tawi-Tawi and Sulu, southern Philippines, where major commercial ESF activities in the country are currently practiced. Seaweed farmers (N = 143) were interviewed using a structured questionnaire containing relevant information on the current farming practices. Results revealed that ESF is one of the primary livelihood sources for coastal inhabitants in the southern Philippines. Most farmers were male, 21–50 years old, and practiced farming for 6–10 years. Farmers mostly owned a farm with an area of 25–400 m2, mainly filled with the rhodophyte elkhorn sea mosses, either Kappaphycus alvarezii or K. striatus. Vegetative cuttings, the major seedling source, were tied using plastic straw into a 6–10 m rope line with a distance interval of 10–20 cm. Inorganic nutrient enrichment is practiced to increase growth and lessen ice-ice disease occurrence. The modified fixed-off bottom (stakes with floaters) is the most predominant farming method. Farms were visited 2–3 times a week for maintenance. Farming is year-round, with peak seasons between August and November. Harvesting is typically done after 21–30 days. Seaweeds are usually dried using the hanging method, which takes 4–6 days. Dried Kappaphycus fronds command higher prices (90–140 PHP/kg) compared to Eucheuma denticulatum (10–50 PHP/kg). Few farmers received government support; therefore, farmers reported many problems affecting their production. This study provides an update on the current ESF practices in the southern Philippines, which have not been well-documented for almost two decades.

Study on water hammer effect and tubing string vibration in high-pressure high-production gas wells

The transient internal flow in high-pressure high-production gas wells generates severe water hammer and tubing string vibration, which accelerates fatigue damage, joint wear, thread loosening, and other wellbore integrity problems. Based on the analysis of transient flow in gas wells, a mathematical model for fluid pressure surge and the induced tubing string vibration is developed and validated by similarity experiments. This method considers fluid-structure interaction, initial loads of tubing string, and compressibility of natural gas, and can fill the gap in quantification of water hammer pressure and tubing sting dynamic load in high-pressure high-production gas wells. On this basis, the effects of valve closure time, production rate, liquid content, and tubing string structure on transient flow and tubing string characteristics are analyzed systematically. The calculations show that wellhead pressure increases rapidly, and pressure wave propagates along tubing string to induce vibrations in the string after an instantaneous shut-in at the wellhead. During this transient process, fluid pressure and axial stress at wellhead reach their maximum valves. Owing to the fixed constraint effect of wellhead and downhole packer, the lack of restrictions on tubing distant from wellhead and packer enhances the severity of axial vibration. As valve closure time increases, the maximum wellhead pressure, tubing vibration displacement, and velocity gradually decrease. Therefore, the most direct way to control water hammer effect and tubing string vibration is to extend the shut-in time or prevent a rapid shut-in of gas well. The methods used in this study and the results obtained therein can serve as both a theoretical framework and practical foundation for the prediction and control of water hammer effect and tubing string vibration in high-pressure high-production gas wells.