Lower Feed Research Articles

Improving microstructure and mechanical properties of WAAMed Al with UV introduced via a torch clamp

Abstract Ultrasonic assisting is considered to be a promising technology for industrial applications due to its ability to improve the quality of the WAAMed component. A specially designed ultrasonically vibrating torch clamp (UV torch clamp) was used to introduce the UV in the WAAM process of Al alloy for the first time. UV effect on the forming accuracy, microstructure and mechanical properties of WAAMed Al thin-walled component were investigated. The results show that the UV applied via the UV torch clamp changed the metal transfer mode, and increased the transfer frequency by at least 7.42% compared with that without UV at various Wire Feed Speed (WFSs). The applied UV caused slight increases in the surface roughness of the deposited thin-wall components at low WFSs and obvious decreases at high WFSs, the most significant reduction occurred with WFS = 8 m min−1, the surface roughness decreased from 1.04 to 0.44. The grain size and the pore size and density in the deposit were significantly reduced by the UV, and the higher the WFS, the greater the grain refinement effectiveness and the pore suppression effectiveness. The UTS and fracture elongation of the specimen with UV application increased by at least 4.6% (from 277 Mpa to 290 Mpa for longitudinal specimen with WFS = 5 m min−1, ) and 3.3% (from 21.42% to 22.12% for vertical specimen with WFS = 8 m min−1) respectively at various WFSs compared to the specimen without UV application.

Trends in the environmental impacts of the Australian pork industry

Context Over the past four decades, major changes have occurred in Australia’s pork industry, affecting productivity and environmental performance. Aims This study determined long-term changes in greenhouse gas and key resource use efficiency indicators. Methods Life cycle assessment was used to determine impacts at decadal intervals between 1980 and 2010, and are presented alongside results for 2020 and 2022. Key results Over 42 years since 1980, greenhouse gas emissions, excluding land use and direct land use change (dLUC), fell by 74% from 11.7 to 3.0 kg CO2-e/kg liveweight. Land use and dLUC emissions declined by 92%. Fossil energy use decreased from 35 to 13 MJ/kg liveweight between 1980 and 2022. Freshwater consumption and water stress fell from 506 L and 671 L H2O-e in 1980 to 52 L and 43 L H2O-e/kg liveweight in 2022, respectively. Land occupation decreased by 42% from 22 m2/kg liveweight in 1980 to 13 m2/kg liveweight in 2022. Over the analysis period, emissions per kilogram of liveweight fell by an average of 1.8% per year, land use and dLUC emissions by 2.2%, greenhouse gas including land use and dLUC emissions by 1.9%, fossil energy use by 1.5%, and freshwater consumption, stress, and land occupation by 2.1%, 2.2%, and 1%, respectively. Between 2010 and 2020, uptake of covered anaerobic ponds resulted in an annual rate of improvement in emissions (excl. land use and dLUC) of 2.9%, however, the rate of improvement fell to 1.4% between 2020 and 2022. Conclusions Long-term improvements were principally driven by improved herd productivity and feed production systems, and changes in housing and manure management. Herd and system efficiencies led to better feed conversion ratio, resulting in lower feed requirements, reduced manure production and lower feed wastage, which reduced manure greenhouse gas emissions. Concurrently, reduced tillage, higher yields, and a decrease in the proportion of irrigation water used for grain production resulted in lower impacts of feed grains. Implications Ongoing changes and improvements in production efficiency have resulted in large gains in environmental performance in the Australian pork industry but new strategies will also be needed to maintain these trends into the future.

Improving nutrient digestibility and health in rabbits: effect of fermented rapeseed meal supplementation on haematological and lipid parameters of blood

BackgroundMany studies conducted on livestock point to fermented rapeseed meal (FRSM) as a component that provides adequate quality and quantity of protein. Additionally, it is a very good source of probiotics, prebiotics, enzymes, and antioxidants. A study was undertaken to assess the impact of a feed supplemented with FRSM fermented with Bacillus subtilis strain 87Y on production parameters, nutrient digestibility, and haematological and lipid indicators of the blood in growing rabbits. Forty New Zealand White rabbits (body weight 816,25 ± 24,98 g) aged 35 days were used in this study. The animals were divided into four groups, a control group (C) was fed a standard diet, while in the diet of three experimental groups, soybean meal (SBM) was replaced with FRSM at 4% (FR4 group), 8% (FR8 group), or 12% (FR12 group).ResultsDetailed analysis revealed that the contribution of FRSM in the rabbit feed, regardless of the amount, had a significant effect on body weight gain (BWG), as well as average daily gain (ADG), compared to the control group (C), (P = 0.017). All groups receiving FRSM had a significantly lower (P = 0.05) feed conversion ratio (FCR) compared to the control group. In rabbits fed a diet containing 8% FRSM, the blood haematological parameters, such as red blood cells (RBC), haematocrit (HCT), haemoglobin (HGB), and mean corpuscular volume (MCV), were significantly higher compared to the control group (P = 0.037). In addition, a significant reduction in the plasma levels of the low-density lipoprotein fraction (LDL-chol), the ratio of total cholesterol to high-density lipoprotein (CHOL/HDL), (P = 0.001), and triacylglycerols (TG), (P = 0.004) were observed in the experimental groups compared to the control group.ConclusionsBased on the encouraging outcomes, it is possible to recommend domestically produced FRSM as a viable substitute for genetically-modified (GM) SBM in rabbit feed.

An experimental study of the response characteristics of end milling operations and their finite element simulation

The present study investigates the effect of milling parameters on cutting forces and performance characteristics in end mill operations using two different types of end milling tools. The end milling experiments were performed on AA7075-T6 grade aluminium alloy using a vertical milling machine fitted with a Kistler dynamometer to acquire the data of cutting forces during the milling operation. A matrix of process parameters was created by varying spindle rotational speed in the range of 500–1200 rpm while the feed rate was kept between 10 and 30 mm/min, keeping a maximum depth of cut of 4 mm. The data obtained from the experimental results were analysed and validated by simulation using the DEFORM-3D software facility. The experimental results reflect that with the increase in cutting speed, the cutting force first increases and then decreases, while an increase in feed rate enhances the cutting forces. The combination of high cutting speed with low feed rate was found to be suitable as the force required in this case exhibits a minimum to achieve both efficiency and machinability for a tool. Validated experimental results can be useful for finding new combinations of parameters in the defined parameter range for milling applications.

Influence of microbubble two-phase feed flow on reverse osmosis desalination using different salt concentrations

This study aims to implement microbubble two-phase flow in the feed stream to improve mass transfer and achieve improved reverse osmosis (RO) process performance. The swirl-flow microbubble generator (MBG), which can effectively generate microbubbles, is integrated into the conventional RO system and has experimentally proven its performance under various operating conditions. To investigate the influence of microbubbles in the feed stream on the RO process depending on the feed concentration, real seawater and two types of artificial brackish water were used as the feed solution. The formation of microbubble two-phase flows in the feed stream had a positive impact on the transmembrane flux and distillate water quality of the RO process; this demonstrates that improved mass transfer due to microbubbles introduced into the feed can effectively attenuate the concentration polarization effect in the RO process. MBG-RO performance using seawater as the feed solution was found to be more pronounced at lower feed pressures and higher airflow rates, with an improvement in permeation flux of up to 16 %. Meanwhile, the MBG contribution to RO performance was lower when using artificial brackish water with relatively low concentration than that when using seawater.

Residual feed intake and gain alters the performance and carcass traits in Nellore cattle.

The residual intake and gain (RIG) aims to select animals that present low feed intake in relation to the expected. This study aimed to evaluate the associations of selection for RIG with performance and carcass traits in Nellore cattle. Initially, residual feed intake (RFI) and residual gain (RG) were determined. From this, the RIG was calculated, and the animals were classified as efficient and inefficient for RIG. The efficient animals for RIG showed higher daily weight gain (DWG), Longissimus muscle area (LMA), and mid-test metabolic body weight (MMBW) than the inefficient ones. No significant correlations were found between subcutaneous fat thickness (SFT), marbling (MAR), LMA, MMBW, and the RIG. Thus, it's concluded that the RIG is a measure that can be used to identify and select animals with higher rates of DWG and LMA without changes in the dry matter intake (DMI), SFT, and MAR. However, this index should still be observed with caution, as it may be dependent on body size. Based on the findings, the selection of animals according to the RIG can be an important factor to generate phenotypic evolution in characteristics such as weight gain and rib eye area without adverse effects on the carcass fat deposition.

Enhanced continuous lithium extraction using self-designed porous nanosorbent fibers in a fixed-bed system: Optimization and mechanistic insights

This study introduced a novel lithium/aluminum layered double hydroxide (Li/Al-LDH) nanosorbent fiber (Li-PNF) engineered for continuous lithium extraction from brine using a fixed-bed system. These fibers featured a three-dimensional interconnected mesh structure and were distinctively encapsulated with needle-like Li/Al-LDH, exhibiting a layer-by-layer configuration. Compared to conventional Li/Al-LDH, Li-PNFs demonstrated abundant mesoporous structure and larger average pore size, facilitating the mass transfer and molecular diffusion of Li+ ions. Li-PNFs possessed a static lithium adsorption capacity of approximately 13.0 mg/g, with notable selectivity against Na+ and K+. Additionally, the Li+ binding energy across three distinct sites within the atomic structure of Li-PNFs proved advantageous, particularly at the Triangle-site-Al-overlapping-O3, which reached −5.72 eV. Fixed-bed adsorption experiments confirmed that lower feed flow rates, higher initial lithium concentrations, and increased bed heights significantly enhanced the Li+ capture efficiency, achieving up to 23.83 % in a single fixed-bed experiment. Based on the prediction of adsorption penetration curves using four empirical models, it was found that the Clark and Thomas models could accurately predict the behavior of Li+ penetration through the bed. Fixed-bed desorption results indicated that optimal lithium recovery was achieved at lower feed rates, reduced lithium concentrations in the desorption solution, and elevated temperatures. Finally, the excellent cyclic adsorption/desorption performance and low preparation cost of Li-PNF further highlighted its potential for real industrial applications, offering a significant advancement in the field of lithium extraction technology.

Extreme mismatch between phytoplankton and grazers during Arctic spring blooms and consequences for the pelagic food-web

Food-web structure determines the cycling pathways and fate of new production in marine ecosystems. Herbivorous zooplankton populations are usually seasonally coupled with pelagic primary producers. Synchrony of phytoplankton blooms with reproduction, recruitment and seasonal ascent of their main grazers ensures efficient transfer of organic carbon to higher trophic levels, including commercially harvested species, especially in high-latitude systems. Changes in light, nutrient, and sea-ice dynamics due to accelerating climate change in the Arctic, however, create large uncertainties in how these systems will function in the future. To address such knowledge gaps, we surveyed the pelagic ecosystem of the Barents Sea Polar Front in May of two consecutive years (2021 and 2022) to investigate the pelagic food-web from primary producers to planktivorous fish. In both years we observed unprecedentedly high phytoplankton chlorophyll a values in open as well as ice-covered waters, much of which was invisible to satellite remote sensing. We also measured very low densities of grazing zooplankton across a wide area and extending for at least one month. This extreme mismatch resulted in low feeding by capelin, and further suggests a high potential for vertical export of carbon to the benthos rather than efficient assimilation into the pelagic food web. As the Arctic continues to warm and is characterized by thinner and more mobile sea ice, we may expect higher variability in phytoplankton bloom phenology and more frequent mismatches with grazer life-histories. This could have significant impacts on ecosystem functioning by re-directing the flow of energy through the system towards seafloor rather than to the production of commercially valuable pelagic marine resources.

Cognitive Stimulation and Maternal Feeding Styles in Families with Low Incomes: Impacts from a Randomized Clinical Trial

ObjectiveTo examine associations between cognitive stimulation in the home at 6 months and maternal feeding styles at 24 months, direct intervention effects of Smart Beginnings (SB) on feeding styles, and potential indirect effects of SB on feeding styles via earlier intervention effects on cognitive stimulation. Study DesignSingle-blind, two-site randomized clinical trial (RCT) of the SB intervention. SB integrates PlayReadVIP, a universal, pediatric primary care-based program, and Family Check-Up (FCU), a targeted secondary home-based parenting intervention. Mother-infant dyads (N=327) were randomized at birth to standard pediatric care or the SB intervention. Linear regression analyses determined associations between cognitive stimulation at 6 months and maternal feeding styles at 24 months, a secondary data analysis. Direct intervention impacts on feeding styles, a secondary RCT outcome, were also assessed and mediation analyses explored intervention effects on feeding styles via earlier intervention impacts on cognitive stimulation. ResultsCognitive stimulation was significantly associated with higher responsive and lower indulgent feeding styles. SB mothers were less likely to exhibit pressuring styles compared with controls (Effect Size [ES]=-0.12, p=0.02). Although no direct intervention effects were found on responsive or indulgent feeding styles, indirect effects of SB were evident on these feeding styles through intervention-induced increases in cognitive stimulation in the SB group. ConclusionThis study found positive linkages between cognitive stimulation in the home and later feeding styles. Additionally, the SB intervention was associated with less pressured feeding and indirect pathways mediated by intervention effects on cognitive stimulation. Implications for early childhood parenting interventions are discussed.

Interaction between energy level and starch: fat ratio on intestinal energy metabolism of layer pullets

During the growing period, the gastrointestinal tract of layer pullets is not yet well developed and may be susceptible to dietary energy level. The energy level and composition might impact the intestinal energy metabolism of layer pullets. To test this hypothesis, a total of 480 “Jing Tint 6” layer pullets were used in an 8-week study and allocated to 4 groups, each consisting of 8 replicates, with 15 birds per replicate. Pullets were treated with low or high starch: fat ratios (LS, 10:1; HS, 20:1) in a 2 × 2 factorial arrangement with regular energy (RE, 11.85 and 11.68 MJ/kg for birds from 6 to 10 weeks of age and 11 to 14 weeks of age, respectively) or low energy (LE, 0.55 MJ/kg lower than RE) levels. A significant interaction (P < 0.05) showed that HS increased glandular stomach weight and the jejunal villus length to crypt depth ratio (VCR) in LE diets, but decreased these parameters in RE diets. Dietary energy reduction impaired energy metabolism in the ileum (P < 0.05) mainly via decreasing the gene expression of enzymes involved in the tricarboxylic acid (TCA) cycle (α-ketoglutarate dehydrogenase complex [α-KGDH]; isocitrate dehydrogenase (NAD (+)) [IDH] catalytic; citrate synthase [CS]) and adenosine triphosphate (ATP) synthesis, reducing contents of phosphoenolpyruvate (PEP) and adenylate energy charges (AEC) and down-regulating the adenosine monophosphate-activated protein kinase (AMPK) pathway. HS stimulated AMPKα phosphorylation, increased protein abundance of peroxisome proliferator activated-receptor gamma coactivator 1α (PGC1α) and improved contents of amino acids (aspartate, glutamate, glutamine, alanine and threonine) and malate in the ileum regardless of energy levels (P < 0.05). By an interaction (P < 0.05), the transition from LS to HS diets up-regulated ileal gene expression of AMPKα1 and decreased content of adenosine monophosphate (AMP), accompanied by higher AEC but only in birds fed with LE diets. Collectively, these results suggest that low energy feeding may not be enough for maintaining intestinal energy homeostasis in layer pullets and emphasizes the importance of a relatively high starch: fat ratio in restoring energy metabolism in the ileum.

Research on grinding parameter optimization based on adhesive semiconductor quartz disc

Abstract To study the influence of grinding parameters on the grinding force of semiconductor quartz disc based on the adhesive clamping method, an orthogonal experiment was designed to investigate the impact of grinding parameters on the grinding force. Based on the orthogonal test data, the influencing factors and parameter optimization of the grinding force are developed. The experimental results show that the order of influence of grinding parameters on the X-axis is feed speed &gt; spindle speed &gt; grinding depth, the sequence of effect on the grinding force in the Y-axis is grinding depth &gt; feed speed &gt; spindle speed, and the order of influence on the grinding force in Z-axis is grinding depth &gt; spindle speed &gt; feed speed. Therefore, using a higher spindle speed, a lower feed rate and a shallower grinding depth can play a role in reducing the grinding force. By improving the grinding parameters, the stability of quartz plate grinding based on adhesive technology is verified. It is found that adhesive is a more reliable clamping method, which ensures the processing quality of quartz plate and improves the working efficiency.

Optimizing feed restriction strategies for profitable Oreochromis niloticus culture in floating cages in riverine ecosystems

High feed cost is a major obstacle for promoting the growth of nutrient-rich fish species like Nile tilapia (Oreochromis niloticus) in cage aquaculture. To address this issue, cage farming of O. niloticus was studied for a 75-day period in the Gurukchi River of Bangladesh. Three different feeding strategies (FS) were tested in floating cages: FS5- weekly restriction on feed supply for two days, FS6- weekly restriction on feed supply for one day, and FS7- no weekly restriction on feed supply, with three replications for each treatment. Water quality parameters were monitored weekly and found within suitable levels for fish cultivation. The analysis of length–weight relationship and the condition factor of O. niloticus showed positive allometric growth regardless of the diverse feeding tactics employed that consistently exhibit stability across all treatments. Both FS6 and FS7 had significantly higher (p < 0.05) final individual length, final individual weight, net yield, total yield, and specific growth rate than FS5. FS6 yielded significantly higher fish production with significantly lower feed conversion ratio than FS7. Economic analysis revealed the highest benefit–cost ratio and net revenue in FS6, recommending its use to minimize the need for supplemental feed and reduce production costs in tilapia cage culture.

A microwave/millimeter-wave triple-band shared-aperture antenna integrating differentially-fed patch and transmitarray

This paper presents a microwave (MW)/millimeter-wave (MMW) triple-band shared-aperture antenna. It is implemented by integrating a differentially-fed patch (3.6 GHz) and a dual-band transmitarray (TA) (26 GHz and 39 GHz) through structure reuse. To realize an efficient integration, the patch antenna is evolved from a single-layer structure to a multi-layer one, with an extended ring-shaped patch added in each layer to obtain a proper transmitting surface (TS) size. For the TA, it adopts a unit cell (UC) consisting of two interleaved slots. By adjusting the lengths of the slots, independent dynamic phase shifts covering 360∘ can be attained for the 26 GHz and 39 GHz bands, respectively. To achieve an appropriate focal-to-diameter ratio (F/D) for the TA, a frequency selective surface (FSS) is employed to replace the ground plane of the patch antenna. Thanks to the spatial feeding architecture of the TA, the proposed antenna eliminates the need of complicated feeding network and features low feeding loss and high gain in the MMW bands. To validate the design idea, a prototype is fabricated and measured. The experimental results demonstrate that the proposed antenna can successfully operate in the three bands with peak gain of 7.6 dBi, 19.3 dBi and 19.5 dBi, respectively. In the 26 GHz and 39 GHz bands, beam scanning ranges of ±25∘ and ±13∘ can be obtained, respectively. The proposed antenna can be a promising candidate for 5G multi-band applications.

An experimental study of ultrasonic-knife cutting for a woven carbon fiber preform by an industrial robot

This study investigates the effect of the cutting process parameters on the cutting forces and the quality parameters of a woven carbon fiber preform during robotic ultrasonic-knife cutting. An ultrasonic cutting device, with a power of 1200 W, a frequency of 24 kHz, and an amplitude of 60 µm, mounted on the end effector of a six-axis degree of freedom industrial robot to make linear cuts. A three-level factorial experimental design was used to examine the effect of the feed rate (1 m/min to 5 m/min) and the knife’s attack angle (45° to 75°) on the cutting forces, the dimensional accuracy of the machined preform coupons, and the damage on the machined preform edges. The cutting force analysis results show that the increasing feed rate resulted in increasing feed force and thrust force. However, the increase of the attack angle increases the feed force but decreases the thrust force. The average width and damage of the ultrasonic knife cut preform coupons are highly related to the process conditions. The combination of the low feed rate, 1 m/min, and the low attack angle, 45°, resulted in dimensional errors ranging from 253 μm to 365 μm oversized from the programmed 15.0 mm width with no damage. When the feed became 3 m/min and 5 m/min at the attack angle of 75°, the preform coupons’ dimensional accuracy and damage formation worsened. In these conditions, the ultrasonic knife attached to the industrial robot arm could not cut the preform plate effectively, so the tows on the preform were unevenly cut or dislodged.

Mid-spatial frequency reduction via zero-depth of cut rapid-feed passes in face-turning

The single point diamond turning process (SPDT) is used widely in creating optical grade mirror surfaces on several engineering materials ranging from polymers, and metals, to brittle materials such as silicon and germanium. In visual optic mirror applications, mid-spatial frequency (MSF) errors generated during the SPDT process interfere with the visible spectrum of light thereby affecting the image quality. To overcome these errors, a post-processing operation of polishing the optical mirrors is required. The post-processing step not only increases the complexity of the manufacturing process but also leads to minor geometrical form changes in the mirror which affects performance. To avoid post-processing and minimize MSFs formed during turning- a novel method to modify the toolpath during the machining process has been proposed in this paper. The suggested toolpath strategy comprises two consecutive operations: i) employing variable low feed rates with the specified depth of cut (DoC) and ii) executing rapid traverse rates with zero depth of cut for a predetermined number of passes. The effectiveness of the proposed strategy is tested by carrying out facing experiments in a micro-precision CNC lathe. The power spectral density (PSD) content of the machined surface is then analyzed to check for any improvement in the frequency characteristics. The results show that the frequency errors generated by the toolpath in normal turning operations can be minimized, distributing the resulting PSD peak over a wide range of spatial frequencies. From the PSD plots, it is observed that there is a decrease of 77% and 85.82% in the peak intensity values when compared with surfaces machined at constant feedrates of 150 μm/rev and 200 μm/rev respectively. This method can be applied to nanoprecision SPDT machines to improve the surface quality and to eliminate the MSF errors of the visual optical grade mirrors without the need for post-processing.

Effect of Azolla meal-based diet on growth performance, haematological profile and proximate composition of common carp (Cyprinus carpio) fry

Optimising the cost of nutrients in fish diets is crucial for aquaculture production, as feed accounts for 50% of operational expenses in intensive aquaculture. The rising demand for mustard oil cake (MOC), a commonly used feed ingredient in Indian aquaculture, has led to a significant increase in its price due to its diverse applications. Azolla (Azolla pinnata), a free-floating freshwater plant, has attracted researchers in fish feed formulation due to its rich nutrient profile. The present study was conducted to evaluate the effects of replacement of MOC with Azolla meal in the diet of common carp (Cyprinus carpio) fry. Pelleted feed was formulated with Azolla meal replacing MOC at levels of 0, 10, 20, 30 and 40% and fed to fish. Growth performance, feed conversion ratio (FCR), haematological parameters and proximate composition in fish carcass were assessed after 90 days of experimental feeding. Simultaneously, a control feed without supplementing of Azolla meal was also prepared. Fish were fed daily with the experimental diets at 8, 6 and 4% of their body weight during the first, second and third months respectively, in the morning hours (10:00 hrs). Principal component analysis (PCA) was performed to assess the effect of formulated diets on fish carcasses composition and haematological parameters. The results showed that replacing 30% of MOC with Azolla meal in the diet, led to significantly (p≤0.05) higher specific growth rate (SGR) and percentage weight gain and significantly (p≤0.05) lower feed conversion ratio (FCR) at this concentration. Fish survival rate ranged from 80.00 to 93.33% among different treatments. Further, significant (p≤0.05) differences were observed in both haematological parameters of fish and the proximate composition of fish carcass. among the different treatments. These findings suggest that MOC can be effectively replaced with 30% Azolla meal in the diet for rearing common carp fry to fingerling stage, without compromising the growth performance. Keywords: Aquaculture, Feed conversion ratio, Health status, Mustard oil cake, Principal component analysis, Specific growth rate, Survival

Investigating the Impact of Robotic Milling Parameters on the Surface Roughness of Al-Alloy Fabricated by Wire Arc Additive Manufacturing

This paper takes the single-wall wall manufactured by wire arc additive manufacturing (WAAM) as the research object and compares it with the as-cast aluminum alloy with the same series. By using feed rate, cutting depth, spindle speed, etc., as single or compound parameters, the machinability of the sample is analyzed. The results indicate that the influence of varying parameters on the as-deposited aluminum alloy follows the order of feed rate &gt; cutting depth &gt; spindle speed. As the feed rate increases, the surface roughness initially decreases and then increases, with the optimal surface quality achieved at 12 mm/s (with a surface roughness of 2.013 μm). Different from the as-deposited alloy, the influence of the parameters on the as-cast alloys follows the order of spindle speed &gt; cutting depth &gt; feed rate. The experiments reveal that, for both as-deposited and as-cast states, the trends of the impact of cutting depth and spindle speed on surface quality are consistent. However, at low feed rates (2–12 mm/s), for as-deposited states, the surface quality of as-deposited samples becomes smoother as the feed rate increases (contrary to common knowledge). This result can be attributed to the elevated milling temperature, which softens the material, making it easier to remove and reducing the surface roughness.

Effect of volumetric concentration factor on virus removal for low-pressure reverse osmosis membrane in drinking water production: A study on different scales

Reverse osmosis membranes are intended to constitute a complete physical barrier against nanometric-sized pathogens such as enteric viruses. Literature describes that low-pressure reverse osmosis achieves high viral removal rates (above 5 log), surpassing those of ultrafiltration (1 to 3 log). However, these studies often used individual viruses and high feed viral concentrations (above 109 virus L-1), greater than typical viral concentrations present in the environment like groundwater, to promote virus detection in the permeate. These high concentrations can promote viral aggregation, potentially affecting the observed retention. This work evaluates the simultaneous elimination of three viruses during the production of drinking water by low-pressure reverse osmosis: two enteric viruses (adenovirus 41 and coxsackievirus-B5) and bacteriophage MS2, a widely used virus surrogate in the literature. The permeates produced by low-pressure reverse osmosis were concentrated to allow virus detection in permeate at lower feed concentrations (106 virus L-1) while staying above the limits of detection and quantification. Experiments were carried out on two pilot plants of different scales (laboratory and semi-industrial) to assess the potential effect of the number of membranes and O-rings on virus retention. The effect of the volume concentration factor on low-pressure reverse osmosis efficiency was evaluated for each scale. Results indicate an average viral reduction of 6 log (up to 7 log), regardless of the size of the virus and/or the scale of LPRO pilot. For the semi-industrial scale, better retention was observed as the volume concentration factor increased. However, viruses were still present in the permeate for each scale (even if close to the detection limit), indicating that retention was not complete. At the same feed viral concentrations, the number of viruses recovered in the semi-industrial scale permeates was higher than in the laboratory scale. A 24-fold greater number of membranes and O-rings used for the semi-industrial scale showed that micro-leaks through O-rings could be responsible for the passage of viruses into the permeate.

Additive effects of Bridelia ferruginea leaf meal as a partial replacement for soybean meal on nutrients digestibility, growth performance, and carcass characteristics of weaner rabbits

BackgroundProtein is a crucial nutrient for enhancing livestock performance and productivity, traditionally sourced from soybean and fish meal. However, issues like erratic availability and rising prices necessitate exploring alternative protein sources. Tropical plants, especially leaf meals, are being considered to replace or supplement conventional protein sources in rabbit diets. Bridelia ferruginea, a plant abundant in West Africa, is recognized for its medicinal properties, but its potential as an animal feed is largely unexplored. This study aims to evaluate the impact of graded levels of Bridelia ferruginea leaf meal (BFLM) as a partial substitute for soybean meal in the diets of weaner rabbits.Materials and methodsThe experiment was conducted at the Animal Science Department of Kwame Nkrumah University of Science and Technology in Ghana. BFLM was obtained by air-drying harvested leaves and milling them. Four diets were formulated, with BFLM partially replacing soybean meal at levels of 0%, 10%, 20%, and 30%. Representative samples of BFLM and all formulated diets were analyzed for their proximate composition and detergent fibre fractions. Twenty-four weaner rabbits were assigned to these diets in a Completely Randomized Design. The study covered a 10-week period, assessing growth performance, nutrient digestibility, carcass characteristics, and economics of production.ResultsThe chemical composition of BFLM revealed favorable attributes for rabbit feeding, with 20.5% crude protein and 92.6% dry matter. Growth performance declined at 30% BFLM inclusion, indicating a possible impact of anti-nutritional factors. Feed conversion ratio increased at higher BFLM levels. Nutrient digestibility showed a decline in dry matter digestibility at 30% BFLM. Carcass characteristics were affected at higher BFLM levels, with dressing percentage decreasing. Weights of internal organs were generally not negatively affected by the inclusion of BFLM. Economic analysis indicated a linear reduction in feed cost with increasing BFLM inclusion.ConclusionThe study suggests that BFLM can be incorporated up to 20% in weaner rabbit diets without compromising productivity, nutrient digestibility, or dressing percentage. Beyond 20%, adverse effects on growth performance and some carcass characteristics were observed. Economically, BFLM incorporation up to 20% lowered feed costs without compromising feed efficiency. Incorporation of BFLM up to 20% in weaner rabbit diets had no adverse effects on the weights and functions of the heart, liver, and kidneys. Overall, BFLM presents a promising alternative protein source for weaner rabbit diets, contributing to cost-effective and sustainable livestock production.

Pilot-scale capacitive deionization for water softening: Performance, energy consumption, and ion selectivity

Capacitive deionization (CDI) has emerged as an efficient process for hardness control than traditional water-softening technologies. However, few systematic studies have been conducted on water softening using pilot-scale CDI systems. For industrial applications, it is essential to investigate deionization performance, energy consumption, and selectivity for divalent cations through pilot-scale studies. In this study, we examined the deionization performance and energy consumption of a pilot-scale CDI process for effective water softening. The key operational variables analyzed were the applied voltage (200–300 V (i.e., 1.0–1.5 V per pair)), feed concentration (550–1250 mg/L), recovery ratio (50–80 %), flow rate (3–5 L/min), and adsorption/desorption time (80–180 s). Within this range, a high voltage, low feed concentration, low recovery ratio, high flow rate, and long adsorption/desorption times are advantageous for the total dissolved solids (TDS) removal ratio. In terms of energy efficiency, expressed as TDS removal per unit energy consumption, a low voltage, low feed concentration, low recovery ratio, fast flow rate, and long adsorption/desorption time are beneficial. Additionally, we investigated the selective removal of Ca2+ over Na+ under various operating conditions, as well as its impact on enhancing energy efficiency. The pilot CDI system achieved a Ca/Na selectivity coefficient of approximately 2.4 and it was analyzed to achieve up to 45 % energy-saving efficiency compared to nonselective systems (i.e., selectivity coefficient = 1). The results of this study are expected to provide valuable data for the application of CDI to water softening and hardness control processes.