Production Related Parameters Research Articles

Qualitative assessment of optimizing the well spacings based on the economic analysis

The design of well spacing significantly influences the sustainability and economic benefit of geothermal energy extraction. However, most studies have predominantly employed heat production-related parameters as indicators of well spacing, and a comprehensive analysis of well spacing design based on an economic model is necessary for practical implementation. In this study, an economic indicator considering the benefits derived from heat production and operating costs is proposed and applied in the Caofeidian, a typical abandoned oilfield in the Bohai Bay Basin. It offers a refined portrayal of directional wells, moving beyond rudimentary representations, to capture their appropriate degree of complexity and behavior in drilling configurations. First, by integrating thermophysical information and site investigation data from previous oil investigations, a heterogeneous 3D model is constructed to forecast the 30-year temperature and pressure evolution. Then, a modified levelized cost of heat (LCOH-HT) is proposed to perform economic analysis in optimizing the well spacing, revealing an optimal range of 300–600 m for the different selected wells. In comparison with results derived solely from heat production considerations, drilling and pumping costs contribute to a 300 m reduction in the optimal well spacing based on the proposed approach, as a larger well spacing leads to increased hydraulic losses and drilling cost, necessitating greater pumping efforts and costs. This finding underscores the need to balance economic and thermal considerations. In addition, we found the difference in the optimal well spacing in space is also caused by the porosity variations. Porosity affects fluid temperature and pressure, leading to changes in the benefits and costs associated with pressure fluctuations. Notably, this novel economic analysis method is not limited to spacing optimization; it can also be used to optimize operating parameters, such as the flow rate, which could provide practical strategies for geothermal energy extraction.

Rapid Production of Nanoscale Liposomes Using a 3D-Printed Reactor-In-A-Centrifuge: Formulation, Characterisation, and Super-Resolution Imaging.

Nanoscale liposomes have been extensively researched and employed clinically for the delivery of biologically active compounds, including chemotherapy drugs and vaccines, offering improved pharmacokinetic behaviour and therapeutic outcomes. Traditional laboratory-scale production methods often suffer from limited control over liposome properties (e.g., size and lamellarity) and rely on laborious multistep procedures, which may limit pre-clinical research developments and innovation in this area. The widespread adoption of alternative, more controllable microfluidic-based methods is often hindered by complexities and costs associated with device manufacturing and operation, as well as the short device lifetime and the relatively low liposome production rates in some cases. In this study, we demonstrated the production of liposomes comprising therapeutically relevant lipid formulations, using a cost-effective 3D-printed reactor-in-a-centrifuge (RIAC) device. By adjusting formulation- and production-related parameters, including the concentration of polyethylene glycol (PEG), temperature, centrifugation time and speed, and lipid concentration, the mean size of the produced liposomes could be tuned in the range of 140 to 200 nm. By combining selected experimental parameters, the method was capable of producing liposomes with a therapeutically relevant mean size of ~174 nm with narrow size distribution (polydispersity index, PDI ~0.1) at a production rate of >8 mg/min. The flow-through method proposed in this study has potential to become an effective and versatile laboratory-scale approach to simplify the synthesis of therapeutic liposomal formulations.

Development of dynamic growth and body composition models for Nile Tilapia (Oreochromis niloticus): An exploratory approach to protein and energy metabolism

The aquaculture sector has been steadily growing and thus there is an increasing need to develop mathematical models that allow the estimation of production-related parameters. Prediction of fish growth, feed requirements and waste outputs, are essential in order to ensure the profitability and sustainability of the production activities. Bioenergetic models have been widely used to estimate growth based on energy budgets, but they have some limitations by not explicitly considering the mass-balance of the main macronutrients (e.g., protein). In turn, nutrient-based models are more explanatory, as they consider both energy and nutrient inputs, and estimate fish growth by simulating nutrient accumulation in the fish body. Although some bioenergetic and nutrient-base models for predicting Nile tilapia growth exist in the literature, their suitability is not entirely clear, since their development is often based on uncertain or suboptimal criteria (e.g., relying solely on calibration goodness-of-fit measures).In this work, Nile tilapia growth datasets covering a wide range of rearing conditions and feed compositions were collected from the scientific literature. An exploratory analysis of the collected data was performed to clarify the relationships between energy/protein intake and gain. In this analysis, a direct relationship was observed between digestible energy intake and energy gain, as well as between digestible protein intake and protein gain. Protein gain showed better efficiency than energy gain, even at higher intake levels and without clear evidence of a saturation effect. While digestible energy intake negatively affects energy retention efficiency, digestible protein intake does not significantly impact protein retention efficiency. Furthermore, while energy retention efficiency varies with fish body weight, the same effect was not observed for protein retention efficiency. Finally, though DP/DE ratio has no apparent effect on energy retention efficiency, it seems to negatively affect protein retention efficiency. Considering these observations, plausible growth models with different levels of complexity were developed and calibrated under a diverse set of assumptions. Additionally, two growth models already published for Nile tilapia were calibrated using the same datasets, and their performance was compared with the models developed in the present study. The exploratory analysis of the data suggests a direct relationship between digestible energy intake and energy gain, and between digestible protein intake and protein gain. Furthermore, fish body weight seems to affect the energy retention efficiency. The results of model evaluation showed that energy-protein flux models (EP models) have lower errors in predicting fish growth than pure bioenergetic models (MAPEbw ∼ 9% against ∼13%, respectively), showing the importance of considering protein intake when estimating Nile tilapia growth. Furthermore, assuming the fixed standard metabolic body weight exponents of 0.80 and 0.70 (for energy and protein, respectively), rather than estimating them from the data, seemingly improved the predictive ability of the models. This approach demonstrates the benefits of coupling bioenergetics with nutrient-based models to predict growth and body composition of Nile tilapia along time.

Metal-based-oxide nanoparticles assisted the in vitro culture growth of Populus alba as micronutrients: essential metabolic processes and genetic stability.

The present study evaluates the in vitro culture growth rate of Populus alba upon using nano metal-based-oxides such as hematite (Fe2O3 NPs), zinc oxide (ZnO NPs), and manganese oxide (Mn2O3 NPs) nanoparticles as analogues of three primary micronutrients such as iron (Fe), zinc (Zn), and manganese (Mn), which exist in soil as micronutrients. Herein, the in vitro culture growth rate was investigated using three different concentrations (i.e., 20, 40, and 60 mg L-1) of as-prepared metal oxide nanoparticles compared to the control. In addition, the as-prepared nanoparticles have been prepared via the co-precipitation method. Furthermore, the physicochemical properties were investigated using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and dynamic light scattering techniques. Overall, a significant difference in the biomass production-related parameters such as fresh weight, shoot length, and root length was observed compared to the control upon the treatment with micronutrient-based nano-metal-oxides (i.e., Mn2O3 > Fe2O3 > ZnO NPs, respectively). In addition, a significant increase in the root number of Populus alba plants upon their treatment with ZnO NPs was observed compared to other prepared nano-metal-oxides and the control. Also, a remarkable increase in the chlorophyll index was monitored upon the treatment with Fe2O3 NPs rather than the other commonly used Mn2O3 and ZnO NPs, respectively. Moreover, RAPD-PCR bioassays were applied, and the actual six primers showed a genetic variation percentage of 34.17%, indicating that Populus alba is highly genetically stable even in highly contaminated soil. As a result, our findings suggest an idea that indicates the ability to enhance the in vitro culture growth rate of Populus alba plants using metal oxide nanoparticles as analogous to essential micronutrients.

Potential Galactagogue Effect of Tri-Than-Thip Remedy on Milk Synthesis in Lactating Rats: Impact on Milk Production-Related Parameters.

Herbal galactagogues have been widely used as a treatment for postpartum hypogalactia due to the potential side effects associated with pharmacological therapy. Tri-Than-Thip (Tri-TT) is a Thai herbal medicine remedy that contains three main components: Cassia fistula, Pithecellobium dulce, and Ficus benjamina. These components are believed to have properties that contribute to milk production. However, despite the traditional use of Tri-TT, there is a lack of academic evidence supporting its efficacy in enhancing milk production. Therefore, the purpose of this study was to investigate the effect of Tri-TT on milk production and determine if it has a galactagogue effect. The weight suckle weight model was used to determine total milk production in lactating rats, while histological analysis was performed to assess the alveolar diameter of the mammary gland. The findings of this study revealed a significant increase in total milk production among lactating rats treated with 500 mg/kg of Tri-TT, compared to the control group. Furthermore, both the Tri-TT and Domperidone-treated groups exhibited a larger alveolar diameter of the mammary gland in comparison to the control group. In summary, these findings provide supportive evidence for the galactagogue activity of Tri-TT. The observed enhancement in milk production may be associated with Tri-TT could potentially be attributed to its ability to widen the alveolar diameter of the mammary gland, thereby facilitating increased milk volume.

On the development and deployment of an IIoT Infrastructure for the Fish Canning Industry

The introduction of IoT technologies in industrial settings is changing the way manufacturing companies perceive their production processes, allowing for more accurate monitoring of production-related parameters. Due to the introduction of IoT technologies and associated enhancements in terms of data acquisition, processing, and availability, it becomes possible for manufacturing companies to tackle complex issues, such as the efficiency of production. In this paper, the development of an Industrial IoT solution targeting the fish canning industrial sector is described, as an approach to identify and monitor raw input material losses as well as water and energy waste, an endemic issue of the sector, promoting an increased efficiency in the production processes. This paper mainly focuses on the description of the implementation of the proposed IoT technologies for monitoring waste and loss, and its deployment in three distinct environments, including at a fish canning manufacturing company.

Simulation Modeling for Energy-Flexible Manufacturing: Pitfalls and How to Avoid Them

Due to the high share of industry in total electricity consumption, industrial demand-side management can make a relevant contribution to the stability of power systems. At the same time, companies get the opportunity to reduce their electricity procurement costs by taking advantage of increasingly fluctuating prices on short-term electricity markets, the provision of system services on balancing power markets, or by increasing the share of their own consumption from on-site generated renewable energy. Demand-side management requires the ability to react flexibly to the power supply situation without negatively affecting production targets. It also means that the management and operation of production must consider not only production-related parameters but also parameters of energy availability, which further increase the complexity of decision-making. Although simulation studies are a recognized tool for supporting decision-making processes in production and logistics, the simultaneous simulation of material and energy flows has so far been limited mainly to issues of energy efficiency as opposed to energy flexibility, where application-oriented experience is still limited. We assume that the consideration of energy flexibility in the simulation of manufacturing systems will amplify already known pitfalls in conducting simulation studies. Based on five representative industrial use cases, this article provides practitioners with application-oriented experiences of the coupling of energy and material flows in simulation modeling of energy-flexible manufacturing, identifies challenges in the simulation of energy-flexible production systems, and proposes approaches to face these challenges. Seven pitfalls that pose a particular challenge in simulating energy-flexible manufacturing have been identified, and possible solutions and measures for avoiding them are shown. It has been found that, among other things, consistent management of all parties involved, early clarification of energy-related, logistical, and resulting technical requirements for models and software, as well as the application of suitable methods for validation and verification are central to avoiding these pitfalls. The identification and characterization of challenges and the derivation of recommendations for coping with them can raise awareness of typical pitfalls. This paper thus helps to ensure that simulation studies of energy-flexible production systems can be carried out more efficiently in the future.

Multi-project scheduling with multi-skilled workforce assignment considering uncertainty and learning effect for large-scale equipment manufacturer

This study addresses a resource-constrained multi-project scheduling and multi-skilled workforce assignment problem for the large-scale equipment manufacturing industry. The goal is to help the production manager perform effective planning and decrease the production cost under delivery constraints. The deterministic duration is used in most past investigations in resource-constrained multi-project scheduling problems. Uncertainty in project execution is neglected. Additional related factors are included in the current study to be close to practical circumstances. The required processing duration and material arrival time are modeled as stochastic variables. The heterogeneous skill efficiency of the internal workforce is considered with the learning effect. Skill efficiency grows with the accumulation of experience. Actual processing time is calculated on the basis of skill efficiency and stochastic process duration. The external workforce is hired when the internal workforce fails to satisfy processing demand. The objective is to minimize the expected integrated cost, which is the sum of tardiness penalty and external workforce cost. A genetic algorithm with a heuristic workforce assignment method is also developed, and a case study is illustrated to explain the scheduling result. The proposed approach with uniform crossover and local search mechanism outperforms other comparative methods by approximately 10.34% considering total costs. Furthermore, the Taguchi method of design of the experiment is conducted to find the optimal parameter setting efficiently. Afterward, the sensitivity analysis of production-related parameters is discussed.

Synthetic model for evaluating CO2 flooding in tight oil reservoir

ABSTRACT With the increasing energy consumption and the exhaustion of conventional oil reservoir, CO2 flooding is becoming one of the key technologies to improve the oil production of tight reservoirs. Not only oil production of CO2 flooding but also its main influencing parameters and quantitative evaluation have attracted people’s attention in recent years. The experimental and numerical techniques are the main approach to evaluate the production and influencing parameters. However, it is expensive and costs a lot of time to use those approaches. To solve the above problems, in this paper, a comprehensive integrated hierarchy and correlation model is initially established to evaluate the production of CO2 flooding and confirm the main influencing parameters. Specifically speaking, the Analytic Hierarchy Process (AHP) and Grey Relationship Analysis (GRA) are used to evaluate the main influencing parameters of oil production for the CO2 flooding process in tight oil reservoirs, respectively. Subsequently, the Rank-Sum Ratio (RSR) is adopted to combine the Analytic Hierarchy Process with Grey Relationship Analysis to acquire the comprehensive weight and ensure the main influencing parameters. The results show that the comprehensive weight of permeability, variation coefficient, sand injection, and reservoir thickness is 0.1157, 0.0937, 0.0914, and 0.0895 and those parameters play a extremely important role in the production of CO2 flooding. The model is applied to eight production wells and the rank–sum ratio is 2.3 to 6.6. The arrange regular of comprehensive results evaluated by the rank–sum ratio has a very consistent relationship with that of production. It is convenient and accurate to evaluate the production-related parameters by using the comprehensive integrated-hierarchy model, and this study provides a functional method to analyze the production performance.

Tailoring the size of ultrasound responsive lipid-shelled nanodroplets by varying production parameters and environmental conditions

Liquid perfluorocarbon nanodroplets (NDs) are an attractive alternative to microbubbles (MBs) for ultrasound-mediated therapeutic and diagnostic applications. ND size and size distribution have a strong influence on their behaviour in vivo, including extravasation efficiency, circulation time, and response to ultrasound stimulation. Thus, it is desirable to identify ways to tailor the ND size and size distribution during manufacturing. In this study phospholipid-coated NDs, comprising a perfluoro-n-pentane (PFP) core stabilised by a DSPC/PEG40s (1,2-distearoyl-sn-glycero-3-phosphocholine and polyoxyethylene(40)stearate, 9:1 molar ratio) shell, were produced in phosphate-buffered saline (PBS) by sonication. The effect of the following production-related parameters on ND size was investigated: PFP concentration, power and duration of sonication, and incorporation of a lipophilic fluorescent dye. ND stability was also assessed at both 4 °C and 37 °C. When a sonication pulse of 6 s and 15% duty cycle was employed, increasing the volumetric concentration of PFP from 5% to 15% v/v in PBS resulted in an increase in ND diameter from 215.8 ± 16.8 nm to 408.9 ± 171.2 nm. An increase in the intensity of sonication from 48 to 72 W (with 10% PFP v/v in PBS) led to a decrease in ND size from 354.6 ± 127.2 nm to 315.0 ± 100.5 nm. Increasing the sonication time from 20 s to 40 s (using a pulsed sonication with 30% duty cycle) did not result in a significant change in ND size (in the range 278–314 nm); however, when it was increased to 60 s, the average ND diameter reduced to 249.7 ± 9.7 nm, which also presented a significantly lower standard deviation compared to the other experimental conditions investigated (i.e., 9.7 nm vs. > 49.4 nm). The addition of the fluorescent dye DiI at different molar ratios did not affect the ND size distribution. NDs were stable at 4 °C for up to 6 days and at 37 °C for up to 110 min; however, some evidence of ND-to-MB phase transition was observed after 40 min at 37 °C. Finally, phase transition of NDs into MBs was demonstrated using a tissue-mimicking flow phantom under therapeutic ultrasound exposure conditions (ultrasound frequency: 0.5 MHz, acoustic pressure: 2–4 MPa, and pulse repetition frequency: 100 Hz).

Effect of irrigation on the production and volatile compounds of sweet basil cultivars (Ocimum basilicum L.)

Summary Introduction: Irrigation plays an important role in the cultivation of medicinal plants. There is a lack of information on intraspecific variability of reactions to the effect of drought. Objective: The aim of the current study was to test the effect of irrigation on four sweet basil (Ocimum basilicum L.) cultivars (‘Genovese’, ‘Kasia’, ‘Keskenylevelű’, ‘Wala’). Methods: In an open field experiment irrigated and non-irrigated treatments were set. Plants were harvested in full flowering stage. Before the harvest, the stomatal conductance and chlorophyll content were measured. The production-related parameters were recorded. In the plant material the glandular hair density, essential oil content and composition (GC-MS) and volatile composition (SPME-GC-MS) were identified. Results: Stomatal conductance of the irrigated plants was 2.5–4.5 times higher than in the non-irrigated ones. The chlorophyll content showed only slight changes. The irrigation had a positive effect on the production. The leaf to stem ratio was not modified by the watering. Irrigation negatively influenced the glandular hair density and the EO content, however it increased the EO yield by 40–129%, depending on the cultivar. Significant compositional changes were registered only in the EO of cultivar ‘Kasia’ for linalool, 1,8-cineole and tau-cadinole ratios. Conclusion: Irrigation increases the biomass and EO yield of basil while the composition of the EO is mostly unchanged. Only slight differences were observed among the cultivars.

Density versus biomass responses of zooplankton to environmental variability in a subtropical shallow lake

ABSTRACT Density and biomass are commonly used in ecological studies of zooplankton. However, these metrics are not functionally equivalent and provide different information regarding community structure. Differences in the response of zooplankton, as estimated through both density and biomass in relation to environmental variability, were investigated in a large subtropical lake. Results based on 2 years of seasonal sampling at 9 points in Lake Mangueira (southern Brazil) showed a large difference in the pattern of dominance of zooplankton between the density and biomass metrics. Ciliates composed >58% of zooplankton density (rotifers 29.4%) but only 16.1% of zooplankton biomass. Analyzing the composition of zooplankton based only on biomass might therefore underestimate the importance of microzooplankton components, which are an important trophic link in pelagic food webs of subtropical systems. The differences between the 2 metrics in relation to abiotic variables were assessed through redundancy analysis. Seasonality was the main factor driving the variability of zooplankton, and density proved to be the best metric to show the seasonal variation of zooplankton taxa and taxonomic groups in relation to environmental conditions. Density was also the most appropriate metric for analyzing annual cycles and the seasonal succession of species. However, the biomass metric was significantly related to production-related parameters (pH and chlorophyll a) and was essential to better understand zooplankton grazing relationships and the trophic structure of the system.

A mathematical model for gas and water production from overlapping fractured coalbed methane and tight gas reservoirs

With the continuous expansion, exploration and development of unconventional natural gas resources, mainly coalbed methane, shale gas and tight gas, some areas overlapped by two or three types of unconventional natural gas reservoirs are explored, e.g., the Linxing, Shilou and Linfen blocks located in the east margin of the Ordos Basin, China. Gas extraction from an individual reservoir becomes not economic as gas resources are not fully recovered; thus, gas coproduction from two or multiple layers is an effective method for improving gas production. In this work, a mathematical model of gas and water two-phase flow for the coproduction of coalbed methane and tight gas is developed. The adsorption characteristics, stress-sensitive and matrix shrinkage effects on coal permeability, and the stress-sensitive effect of tight sandstone are all considered in the model. The gas production related parameters, such as bottom hole flowing pressure, reservoir pressure differences, reservoir properties (e.g., permeability, cleat compressibility of coal, and Langmuir isotherm parameters) are discussed and compared with different geological conditions. The results show that the gas and water flow from the coalbed and sandstone reservoirs show no interference between each other under a constant pressure drainage system; the sandstone reservoirs show a fast pressure drawdown with a high gas production rate decline, while the coalbed reservoir is slow in pressure drawdown and the gas production rate increases gradually. The properties of a specific reservoir have a great influence on its own gas production performance, but with no influence on the other reservoirs. It was found that a lower constant drainage pressure should be adopted in the case of stress-sensitive effects, and coal with a lower cleat compression coefficient and Poisson's ratio value is better for higher gas production. The production contribution from each layer can be acquired if a specific production rate is set. If the reservoir pressure difference between the two reservoirs is too high (for instance at least > 3 MPa in the cases studied in this work), gas and water intrusion may happen, but the reservoirs would be balanced quickly. Thus, the coproduction of coalbed methane and tight gas from one well bore is feasible, and more work should be conducted on proposing a proper drainage strategy to improve the gas resource recovery efficiency in coal-bearing strata.

Physiological and agronomical responses to environmental fluctuations of two Portuguese grapevine varieties during three field seasons

Extensive agricultural losses are attributed to heat, often combined with drought. These abiotic stresses occur in the field simultaneously, namely in areas with Mediterranean climate, where grapevine traditionally grows. The available scenarios for climate change suggest an increase in the frequency of heat waves and severe drought events in summer, also affecting the South of Portugal. In this work we monitored several production-related parameters and evaluated the state of the oxidative stress response apparatus of two grapevine varieties, Touriga Nacional (TN) and Trincadeira (TR), with and without irrigation, during three field seasons (2010 to 2012). Overall, results point to a high correlation of most yield and stress-associated parameters with the specific characteristics of each variety and to each season rather than the irrigation treatments. In the season with the driest winter, 2012, the lack of irrigation significantly affected yield in TR, while in the two other seasons the impact of the irrigation regime was much lower. In 2012, the yield of TN was affected by environmental conditions of the previous season. The irrigation treatments significantly affected berry size rather than quality.

Different growth performance, lipid deposition, and nutrient utilization in in-season (S1) Atlantic salmon post-smolt fed isoenergetic diets differing in protein-to-lipid ratio

The aim of the present study was to evaluate how isoenergetic diets with different protein-to-lipid ratio affects feed intake, growth performance, lipid deposition, feed and nutrient utilization in Atlantic salmon post-smolt. A 6-month's feeding trial was conducted with in-season (S1) Atlantic salmon post-smolt reared in the sea under natural conditions (May–September). Quadruple groups of salmon (initial weight 95g) were fed two isoenergetic diet series formulated to contain a high (HP) and low (LP) protein-to-lipid ratio designed to resemble upper and lower levels of ratios used in commercial feeds. The group fed the HP diet had a significantly (P≤0.05) lower muscle fat content (HP=4.7%, LP=5.7%), whole body lipid (HP=9.0%, LP=9.6%) and energy content (HP=7.7MJkg−1, LP=8.0MJkg−1) than the group fed the LP diet after the period June–July. These differences were mainly due to significantly lower absolute apparent lipid retention in the summer period for post-smolt fed HP diet. In the subsequent experimental period (July–September), a significantly higher specific feed intake (HP=1.38%, LP=1.33%), thermal growth coefficient (HP=3.82, LP=3.46) and weight gain (HP=658g, LP=552g) were observed for fish fed the HP diet. The period from July–September was associated with high water temperatures and declining day length. The reduced feed intake in the LP group coincided with increased visceral mass and lipid deposition, indicating a possible involvement of lipostatic regulation. The retention efficiency of nutrients increased with the up-regulation in feed consumption. The HP fed fish had a significantly higher whole body lipid retention (HP=74.4%, LP=67.2%), but significantly reduced visceral mass compared to LP fed fish during the autumn. The overall improved growth, good protein utilization and reduced visceral adiposity among the HP fed fish resulted in significantly improved final condition factor (HP=1.46, LP=1.40), carcass yield (HP=86.0%, LP=84.1%), feed conversion based on gutted weight (HP=0.98, LP=0.93) and whole body protein (HP=17.6%, LP=16.9%). The present study reveals that low dietary protein-to-lipid ratios for salmon post-smolt may negatively affect production parameters, although digestible energy contents in the diets are similar. Statement of relevanceThe present study confirms the importance of balanced dietary lipid-to-protein ratios for optimal production efficiency and nutrient utilization, and the significant effects of dietary and seasonal interaction on lipid deposition and production related parameters. To our knowledge, few have investigated the effect of isoenergetic diets differing in protein-to-lipid ratio on growth performance and nutrient utilization of juvenile Atlantic salmon reared in seawater under natural conditions. The experiment used feed formulations, fish breed and rearing conditions relevant for current commercial salmon farming practices.Considering the current increase in the cost of lipid sources, it would be beneficial for the aquaculture industry if dietary lipid content could be reduced without compromising growth and feed utilization of the fish. We believe our findings will provide useful and relevant information regarding dietary formulations and nutritional knowledge for the global fish feed industry and salmon producers.

1078 Hematocrit, milk yield, and production related parameters comparisons between slick and wild-type-haired Puerto Rican Holstein cows

1078 Hematocrit, milk yield, and production related parameters comparisons between slick and wild-type-haired Puerto Rican Holstein cows

Effects of subclinical Mycobacterium avium ssp. paratuberculosis infection on some physiological parameters, health status and production in dairy cows

Milk yield, milk ingredients, health and other, production-related parameters of subclinically infected, Mycobacterium avium ssp. paratuberculosis (MAP-) shedding (positive faecal PCR, n = 20) and non-shedding (negative faecal PCR, n = 10) dairy cows were compared in the period from 10 days prepartum to 120 days postpartum. Body condition, rumen fill and faeces scores were lower in the MAP-shedding cows. There was no significant difference in plasma or urine metabolic parameters between the groups. Milk yield and lactose content tended to be lower (P = 0.074 and 0.077, respectively), somatic cell count tended to be higher (P = 0.097), while milk fat content was significantly higher (P = 0.006) in MAP-shedding cows than in the controls. Milk protein content did not differ between the groups. All other health and production parameters [number of reproductive tract treatments, number of udder treatments, number of artificial inseminations (AIs), calving interval, and service period] were significantly better in the control group. It is concluded that MAP infection, even in a subclinical form, has a significant impact on some production and health parameters of dairy cows.

Sand production model in gas hydrate-bearing sediments

This paper provides a comprehensive analytical formulation that entails the features of sand production in gas hydrate-bearing sediments, including grain detachment, migration, sediment deformation and hydrate dissociation. The formulation is thermo-hydro-mechanically coupled such that grain detachment causes stress reduction, sediment shear deformation induces grain detachment and grain flow alters multiphase fluid pressure and temperature profiles. Through a series of analyses, the sensitivity of sand production related parameters on resulting solid volume changes is evaluated. Furthermore, the effect of various operational methods on mitigating sand production in hydrate-bearing sediments during gas production is numerically investigated. It is found that, out of the different operational methods investigated, lowering depressurization rate was the most effective in reducing sand production for a given gas production.

Opinion of Belgian Egg Farmers on Hen Welfare and Its Relationship with Housing Type.

Simple SummaryUntil 2012, laying hens in the EU were often housed in conventional cages that offered limited space and few opportunities to perform highly motivated behaviors. Conventional cages are now banned in the EU in order to improve animal welfare. In this study, egg farmers were surveyed (winter 2013–2014) to assess whether they perceived any changes in animal welfare since changing housing systems, what role hen welfare played in choosing a new housing system, and which aspects of hen welfare they find most important. The data show that the answers differ depending on which housing system the farmers currently use and whether they had used conventional cages in the past.As of 2012, the EU has banned the use of conventional cages (CC) for laying hens, causing a shift in housing systems. This study’s aim was to gain insight into farmers’ opinions on hen health and welfare in their current housing systems. A survey was sent to 218 Belgian egg farmers, of which 127 (58.3%) responded, with 84 still active as egg farmer. Hen welfare tended to be less important in choosing the housing system for farmers with cage than with non-cage systems. Respondents currently using cage systems were more satisfied with hen health than respondents with non-cage systems. Reported mortality increased with farm size and was higher in furnished cages than in floor housing. Feather pecking, cannibalism, smothering and mortality were perceived to be higher in current housing systems than in CC, but only by respondents who shifted to non-cage systems from previously having had CC. Health- and production-related parameters were scored to be more important for hen welfare as compared to behavior-related parameters. Those without CC in the past rated factors relating to natural behavior to be more important for welfare than those with CC. This difference in opinion based on farmer backgrounds should be taken into account in future research.

Global sensitivity analysis of DRAINMOD-FOREST, an integrated forest ecosystem model

Global sensitivity analysis is a useful tool to understand process-based ecosystem models by identifying key parameters and processes controlling model predictions. This study reported a comprehensive global sensitivity analysis for DRAINMOD-FOREST, an integrated model for simulating water, carbon (C), and nitrogen (N) cycles and plant growth in lowland forests. The analysis was carried out for multiple long-term model predictions of hydrology, biogeochemistry, and plant growth. Results showed that long-term mean hydrological predictions were highly sensitive to several key plant physiological parameters. Long-term mean annual soil organic C content and mineralization rate were mainly controlled by temperature-related parameters for soil organic matter decomposition. Mean annual forest productivity and N uptake were found to be mainly dependent upon plant production-related parameters, including canopy quantum use efficiency and carbon use efficiency. Mean annual nitrate loss was highly sensitive to parameters controlling both hydrology and plant production, while mean annual dissolved organic nitrogen loss was controlled by parameters associated with its production and physical sorption. Parameters controlling forest production, C allocation, and specific leaf area highly affected long-term mean annual leaf area. Results of this study could help minimize the efforts needed for calibrating DRAINMOD-FOREST. Meanwhile, this study demonstrates the critical role of plants in regulating water, C, and N cycles in forest ecosystems and highlights the necessity of incorporating a dynamic plant growth model for comprehensively simulating hydrological and biogeochemical processes. Copyright (C) 2013 John Wiley & Sons, Ltd.