Conventional Spray Research Articles

Comprehensive assessment of intelligent unmanned vehicle techniques in pesticide application: A case study in pear orchard.

The intelligent pesticide application techniques in orchards have grown rapidly worldwide due to the decrease in agricultural populations and the increase in labor costs. However, whether and how intelligent pesticide application techniques are better than conventional pesticide application remains unclear. Here, we evaluated the performance of the unmanned aircraft vehicle (UAV) and unmanned ground vehicle (UGV) on pesticide application, ecological environment protection, and human’s health protection compared to conventional manual methods. We quantified characteristics from the aspects of working effectiveness, efficiency, environmental pollution, water saving and carbon dioxide reduction. The results showed that the UAV application has the advantages of a higher working efficiency and less environmental pollution and natural resource consumption compared to the UGV and conventional manual methods despite of its worse spray performance The UGV application techniques could improve spray performance at the cost of high environmental pollution. The conventional spray gun technique was unfriendly to environmental and resource protection although it showed a better spray performance. Thus, the balance of improving spray performance and controlling environmental pollution is the key to improve the performance of UAV and UGV technology in the future. The study could be useful in the development of intelligent pesticide application techniques and provide scientific support for the transition of intelligent management in orchards.

Construction of Economical Dip-Coater for the Fabrication of Hydrophobic Coatings

D.C. motors are considered the basic components for the construction and development of various nanotechnology research equipment due to their constant speed and high efficiency. Spin coater, dip-coater, and spray pyrolysis were a few among them which utilize the above-mentioned component for the production of thin-film coatings on the desired substrates. Conventional spin coater, dip-coater, and spray pyrolysis are expensive to install in research laboratories. In this letter, we report the economical construction of an Arduino-based dip-coater that uses a linear actuator consisting of a D.C. motor for the production of hydrophobic coatings. The dip and drawl rate of the as-constructed machine was estimated to be 3mm/sec and can be varied according to the requirement without any interferences of vibration. Further, the dip-coater was tested with TiO2 gel for the production of hydrophobic coatings on cotton fabrics. The coated fabrics were characterized using an X-ray diffractometer (XRD), which confirmed the presence of TiO2, and reflectance analysis using ultraviolet-visible and near-infrared spectroscopy (UV-VIS-NIR) on the coated fabric revealed an increase in the visible and IR range and a decrease on the ultraviolet spectral region. The goniometer investigation with a water droplet on the treated fabric revealed 137O contact angle and the coating is proved as a super hydrophobic coating.

Image-Enhanced Endoscopy Surveillance of Colon and Pouch Dysplasia in IBD.

Patients with longstanding ulcerative colitis and Crohn's colitis are at risk for developing colorectal cancer and need regular endoscopic surveillance to detect and remove precursor lesions. To do so, different technologies are available. The sources are observational and controlled studies, meta-analysis, and expert consensus articles available on PubMed. The selected materials include articles reporting outcomes of and recommendations on endoscopic surveillance and resection of dysplasia in the gastrointestinal tract, including the ileoanal pouch and the anal transition zone, in patients with inflammatory bowel disease. Incidence and detection rate of dysplasia and cancer with different endoscopic techniques in patients with inflammatory bowel disease. Risk of cancer is proportional to the duration and extent of the disease, and surveillance interval should be tailored on the individual risk in a range of 1 to 5 years. High-definition imaging and virtual chromoendoscopy have improved the detection of dysplasia and are now comparable with conventional dye spray chromoendoscopy. After restorative proctocolectomy with ileoanal pouch, the risk of cancer is modest, but its high mortality warrants endoscopic surveillance. The evidence to guide pouch surveillance is limited, and recently, the first expert consensus provided a framework of recommendations, which include an initial assessment 1 year after surgery and follow-up depending on individual risk factors. The limitation includes scarcity of data on ileoanal pouch surveillance. Virtual chromoendoscopy and high-definition imaging have improved endoscopic surveillance, and more progress is expected with the implementation of artificial intelligence systems.

(Keynote) New Fabrication Methods and Cathode Designs for Nanofiber Electrode Fuel Cell MEAs

When fuel cell electrodes are prepared by a conventional spraying or slot-die coating method, there is little or no control over the multi-scale organization of catalyst particles and polymer binder. Electrode features such as particle and binder interconnectivity, macro-porosity, and micro-porosity are difficult to control, but are critically important when high-performance nanocatalysts are used in fuel cell electrodes. Consequently, the excellent oxygen reduction reaction activity observed in rotating disk experiments with next-generation catalysts does not usually translate into improved hydrogen/air fuel cell performance when such catalysts are incorporated in membrane-electrode-assemblies (MEAs). Nanofiber electrospinning is an electrode fabrication technique that can address fuel cell electrode morphology issues for next-generation MEAs. As a commercial fabrication method, electrospinning is scalable, robust, and cost-effective, especially for the creation of non-woven mats of sub-micron-diameter polymer fibers. In addition to the production of polymer nanofibers, electrospinning can also be used to prepare particle/polymer fiber networks with intra- and inter-fiber porosity. Such fiber mats have been used as the electrode material in Li-ion batteries and H2/air proton-exchange membrane fuel cells [1-4].In this talk, new experimental results will be presented on nanofiber mat electrode MEAs with Pt/C and Pt-alloy catalysts at cathode loadings of 0.1 and 0.2 mgPt/cm2. Methods for electrospinning fibers with different ionomer binders will be described and new methods of incorporating particle/polymer nanofibers into MEAs will be discussed, with a focus on: (a) developing techniques that can be used with existing roll-to-roll MEA processing lines and (b) varying the electrode morphology at the nano and micron scales. Hydrogen/air fuel cell power output and durability results will be contrasted with data obtained for conventional electrode designs. Acknowledgments This work was funded by the U.S. Department of Energy’s Fuel Cell Consortium for Performance and Durability, DOE-EERE FC-PAD Project DE-EE0007653.

Intercomparision of Drone and Conventional Spraying Nutrients on Crop Growth and Yield in Black Gram

An experiment was conducted to reveal the effect of drone spraying of foliar nutrients on the crop growth and yield in black gram at Agricultural Research station, Bhavanisagar in Random block design with 12 treatments with 3 replications. The biometric parameters viz., plant height, leaf area, dry matter production and yield parameters viz., number of pods plant-1, haulm yield and grain yield were influenced more by drone spaying treatments than conventional method of knapsack spraying. The results revealed that Fuel operated drone spray of 2% pulse wonder with spray fluid of 75 L ha-1 using atomizer nozzle recorded the highest growth and yield attributes values. The treatment which registered the highest grain and haulm yield of 784 and 1525 kg ha-1 and it was performed better than as compared to foliar spraying of all 19 solution with fuel operated drone the and the lowest yield was noticed in control. From this study it is concluded that fuel operated drone spray of 2% pulse wonder using the atomizer nozzle with spray fluid of 75 L ha-1 is adopted to enhance the growth and grain yield of black gram.

Spray Freezing Coating on the Carrier Particles for Powder Preparation

Carrier particle spray freeze-drying is a new technology with high added value for thermosensitive powder spray freeze-drying. The technology includes the following steps: atomization, coating, freezing, and drying. Due to the action of carrier particles, the condensation of frozen droplets in the conventional spray freeze-drying process is overcome. However, there are many influencing factors involved in the process of freezing coating. The mechanism of the complex droplet collision freezing process still needs to be studied. In this paper, from the perspective of spray freezing coating after atomized droplets collide with low-temperature carrier particles, the coating process and freezing process of single droplets impacting the sphere are analyzed microscopically. The freezing coating processes of static and dynamic carrier particles are reviewed. Moreover, the surface evaluation of powder and equipment development for creating powder products is discussed.

Wet electrostatic scrubbing for flue gas treatment

This work presents experimental and modeling results on SO2 and combustion particles’ removal in a pilot-scale wet electrostatic scrubber (WES). The WES unit was operated either as: i) a conventional spray scrubber (WS); ii) with only electrified spraying (CDES), and iii) with electrified spraying and corona pre-charging (OPES) by using a model seawater as absorbing liquid. The experiments indicated a progressive improvement of the SO2 fractional approach to equilibrium by increasing the spray charge density in CDES configurations. Corona pre-charging further increased the SO2 absorption rate of OPES compared with CDES configuration, thanks to the parallel depletion of ionized SO2 on the scrubber walls. The fractional approach to equilibrium increased from around 87% for WS to around 97% for OPES. Similarly, the overall particle capture increased by increasing the spray charge density and the corona pre-charging potential: for WS configuration, the particles’ removal efficiency was negligible, while becoming up to 91% under OPES configuration. CDES provided intermediate performances. Experiments can be described with high accuracy for SO2 absorption in WS and CDES configurations, and for particle capture in OPES configurations. Further efforts are needed to describe the other conditions.

Enhanced infiltration and morphology of bismuth perovskite in Carbon-stack solar cells – A synergistic effect of electric fields in modified spray technique

Carbon-based perovskite solar cell (C-PSC) is the breakthrough device architecture, with all printable layers, owing to its ease of fabrication and scope of commercialization. However, infiltration of the perovskite into this prefabricated monolithic C-PSC is a cumbersome process since it needs the adequate material to reach the mesoporous TiO2 (m-TiO2) layer through a thick C- electrode and ZrO2 (separator) and crystallize uniformly. Herein, using the modified electric field (EF) assisted spray technique and with a greener solvent system for the Bismuth Perovskite (Bi-perovskite), its infiltration in the C-PSC stack is demonstrated. A conventional spray system is modified with two different EFs at the nozzle (M−EF) and the substrate (A-EF). The developed protocol promotes controlled infiltration of perovskite at a faster rate (∼2 mins), addressing the infiltration issue in C-PSCs.Consequently, the efficiency of spray devices is improved by ∼ 80% compared to the drop-casted devices. The enhanced stability of the Bi-perovskite, resulting from the selective plane growth, suggests another significant improvement by employing the proposed spray technique. The substantial efficiency and stability improvement attained using a greener solvent system (Acetone-DMF) add an advantage to the process. Hence, the work highlights the first-ever spray-processed non-lead perovskite using the greener solvent system for a large area hole transport layer (HTL) free C-PSC device.

Unraveling the role of operating pressure in the rapid formation of Cu-BDC MOF via a microdroplet approach

A microdroplet-based spray process has been recently developed for the synthesis of metal–organic frameworks (MOFs) which features a short processing time and scalable manner. In this process, atomized microdroplets of the MOFs precursor solution undergo well-controlled physiochemical transformations with each droplet serving as a microreactor. Droplet transformation is closely related to the flow patterns of the spray system. A conventional spray system is operated at atmospheric pressure (under the continuum flow regime). By lowering the operating pressure, the spray system is transitioned to a free-molecular flow regime, where the transport phenomena of the microdroplet become distinct due to the discrete surrounding gas. It is hypothesized that the MOFs formed under this condition could have unique morphological and structural features. Nevertheless, this topic has rarely been investigated. This work studies the formation of the copper 1,4-benzenedicarboxylate (Cu-BDC) MOF under changing flow regimes by modulating the operating pressure. Specifically, changes in crystal size, morphology, and orientation, as well as surface oxidation state, are observed with decreasing operating pressure. Heat and mass transfer calculations, accounting for the transition of flow regimes, suggest that these variations are related to different evaporation rates of the microdroplets. Our study also suggests that the dissociation of solvent molecules from Cu-BDC under sub-ambient pressure increases open metal sites which lead to a strong CO2 binding affinity. This work illustrates the synthesis of MOFs under substantially low operating pressures and offers many new opportunities in the controlled synthesis of MOFs for selective gas adsorption.

Efficient Herbicide Delivery through a Conjugate Gel Formulation for the Mortality of Broad Leaf Weeds.

Carfentrazone-ethyl is embedded in guar gum to prepare a polymer–herbicide conjugate gel formulation for a sustained release of the active ingredient (a.i.). The sprayable gel formulation was optimized at 0.5% (w/v) concentration. Strong interactions of the prepared composition of the polymer–herbicide conjugate system are shown through spectroscopic techniques, depicting the peak broadening of hydrophilic −OH bonds in the herbicide at 1743 cm–1, shifting to 1730 cm–1 in the polymer–herbicide sample. There is a broadening and shifting of the peak at 329 nm for the n → π* transition at 335 nm in the polymer–herbicide conjugate system in UV spectra. Differential scanning calorimetric measurements show a lowering of endothermic melting peaks to 242 and 303 °C in the polymer–herbicide conjugate. X-ray diffraction studies showed a sharp diffraction peak of the pure polymer at a 2θ of ∼20.3°, while broadening and shifting of the peak position to a 2θ of ∼20.8° were observed after adding the herbicide. Diffusion of the active ingredient in the polymer–herbicide conjugate resulted in much greater coverage (most of the weed leaf stomata (>95%)) than conventional spraying. The efficacy of both the polymer–herbicide formulation and herbicide at different doses in weed nurseries showed significantly higher weed mortality in Anagallis arvensis (95.4%), Chenopodium album (∼97%), and Ageratum conyzoides (93.16%) treated with the polymer–herbicide formulation @ 20 g a.i. ha–1. Narrow SPAD readings range of A. arvensis (0.1–30.6) and that of C. album (0–5) were observed in the polymer–herbicide formulation @ 20 g a.i. ha–1 was at par with the conventional formulation @ 30 g a.i. ha–1. Less regeneration in a weed nursery of A. arvensis (27%), C. album (77%), and A. conyzoides (49%) treated with gel formulations @ 20 g a.i. ha–1 was observed, which was significantly lower than those in conventional herbicides.

Plaster beetle (psocid) infestation in buildings : Environmental management and control — a pragmatic approach

Plaster beetles (psocids) are active stocky and soft-bodied insects that are commonly found in new-build apartments, flats and housing blocks. They are also commonly called barklice or booklice because of their superficial resemblance to certain species of lice, and because they are found, sometimes in very large numbers, on mouldy books and papers in damp buildings or their basements and under loose, damp bark. Plaster beetles are either pale grey or pale brown in colour and may or may not have wings. They are common but harmless, unpleasant nuisance pests. Many live on bark and leaf surfaces feeding on algae, fungi or lichens. Others are found in leaf litter or in caves. A small number have extended their range to include buildings and building materials such as thatch, stored food stocks and museum exhibits. Plaster beetle infestation is mainly caused by damp and residual moisture, resulting in high levels of relative humidity (> 65–75 per cent) in the structural voids, ducting and insulation thereby allowing mould infestation. Psocids primarily feed on fungi and moulds for a few months in newly built houses after the completion of a building. Spraying with chemical treatments will deal with the symptoms of the problem but will not deal with the underlying causes of the infestation, namely damp, residual moisture and moulds. Heating treatment offered by some companies, whereby the building is heated to 45°C, should kill off psocids in the building; however, this does not address the underlying cause(s) of the problem and there is a risk of reinfestation. The author has advocated non-destructive investigations of buildings combined with correct diagnosis and identification of type and viability of both plaster beetle and mould infestation, as not all mould infestations are equally toxic or pathogenic. The author strongly believes, based on scientific, practical experience and successful case studies over the last 35 years, that environmental control of plaster beetle infestation and preventative maintenance are preferable to remedial conventional chemical spraying treatments. Rectifying building defects combined with drying out the building fabric and preventative maintenance should in most cases forestall the need for major interventions, and it is beyond doubt that these steps reduce the risk of reinfestation in buildings. The environmentally sustainable approach and the ongoing monitoring of the environmental conditions in buildings ensures the long-term health of building materials, health of the occupants and structures.

Preparation and CMAS Wettability Investigation of CMAS Corrosion Resistant Protective Layer with Micro-Nano Double Scale Structure

Solution precursor plasma spray (SPPS) can prepare thermal barrier coatings (TBCs) with nanostructures, which can modify the adhesion and wettability of molten silicate environmental deposits (CMAS) on the surface of TBCs, thereby improving the resistance of TBCs to CMAS corrosion. In this study, SPPS layers with micro-nano double scale structures were prepared on the surface of conventional atmospheric plasma spraying (APS) coatings. The effect of process parameters on the micro-nano double scale structures and the wetting and infiltration behavior of molten CMAS on the surface of coatings were investigated. The results show that micron structure is more sensitive to process parameters. Lower precursor viscosity, closer spraying distance, and smoother APS layer are favorable to form more typical and dense micron structures. After covering the SPPS layer, the CMAS wetting diameter is reduced by about 40% and the steady-state contact angle increased up to three times. The reason is that the micro-nano double scale structures can effectively trap air and form an air layer between the coating surface and the molten CMAS. In addition, nano-particles play a more important role in the formation of the air layer, which in turn determines the steady-state wettability properties. While micron structures can influence the time needed to reach the steady state. However, the SPPS layers composed of nano-particles have a very loose structure and weak cohesion, and they degrade and fail rapidly after the infiltration of molten CMAS. Therefore, maintaining the excellent CMAS wetting resistance of the SPPS layers while taking into account their lifetime and reliability has become the focus of further research.

The Efficacy of Conventional Spray, Electrostatic Spray, and Dip with a Combination of Hydrogen Peroxide and Peroxyacetic Acid To Inactivate Listeria monocytogenes on Apples

This study aimed to evaluate the efficacy of a hydrogen peroxide (H2O2) and peroxyacetic acid (PAA) mixer delivered by conventional garden spray (GS), electrostatic spray (ES), and dip methods to inactivate Listeria monocytogenes on apples. Organic Honeycrisp, Fuji, and Pink Lady apples were dip inoculated with L. monocytogenes (two strains, serotype 1/2b), which were then kept untreated (control), sprayed with water only, or treated with the H2O2-PAA mixer (0.0064, 0.1, 0.25, and 0.50%) for 20 s via GS, ES, or dip, followed by draining (for 2 min) on aluminum foil. Surviving bacteria were recovered on modified Oxford agar. Atomic force microscopy was used to detect the structural changes of inactivation of L. monocytogenes in broth medium by the H2O2-PAA mixer solution. Data (two replicates, with six samples per replicate) were analyzed using the mixed model procedure of SAS (P = 0.05). Initial counts of L. monocytogenes on untreated apples were 6.80 to 6.90 log CFU per apple. The dip method was the most effective treatment (P < 0.05) for pathogen reductions (2.31 to 2.41 log CFU per apple), followed by GS (1.44 to 1.70 log CFU per apple) and then ES (0.84 to 1.20 log CFU per apple). Reductions of L. monocytogenes were greatest (P < 0.05) when apples were treated with H2O2-PAA mixer -0.25 and -0.50%. Atomic force microscopy analyses indicated that inactivation of L. monocytogenes cells in H2O2-PAA mixer solutions resulted from disruption of the outer membrane. The H2O2-PAA mixer-treated cells had increased width and height and decreased roughness compared with the untreated cells. Results suggested that applying a H2O2-PAA mixer by dip or GS methods is better for pathogen reduction than ES on apples.

Structure of the ethanol spray flame under conventional and MILD conditions

A numerical examination is carried out on the experimental MILD turbulent spray burner of Delft Spray in Hot Co-flow, DSHC. The RANS approach is combined with the Lagrangian tracking of droplets for modeling the pressure-swirl atomizer. The EDC combustion model is employed, to take into account detailed chemical mechanisms. Predictions show that the structure of the triple-flame of liquid fuel in the atmospheric condition is different from the conventional gaseous triple-flames. Furthermore, the structure of the MILD spray flame is compared to the non-MILD spray flame. The flame index shows that the triple-flame structure in the conventional spray flame that consists of two outer and middle diffusion branches, and a premixed inner branch converts to a double-flame structure under MILD condition, including an outer diffusion and a premixed inner branch. In another step, sensitivity analysis relative to the temperature, and oxygen concentration of the co-flow stream is performed independently, which was not possible in the experiment. The parameter of ignition delay time is used for the selection of parametric study cases. Moderate preheating could lead to deviation from the MILD combustion regime, while high preheating is beneficial. NO pollutant generation shows more sensitivity to dilution rather than preheating in MILD spray flame. This study showed that increasing or decreasing each of the temperature and oxygen concentration doesn’t improve all the effective aspects toward achieving the MILD condition. So, the effective parameters should be changed according to a specific and more precise goal.

Theoretical and experimental study of the multistage dynamic dehumidifier for enhanced thermal comfort conditions in a building

In the present study, a mathematical model is constructed to simulate the heat and mass transfer process in a counterflow multistage reciprocating dehumidifier unit. Four packings are positioned at different positions where a camshaft mechanism controls their linear motion. Packings dip inside the Calcium Chloride desiccant instead of the conventional spray technique, improving the wettability and dehumidification effect. Theoretical and experimental results are compared. System performance is analyzed by varying the number of packing and performance parameters such as outlet temperature, specific humidity, moisture effectiveness, moisture removal rate, mass transfer coefficient and pressure change. Results indicated that the system gave maximum moisture effectiveness, moisture removal rate and mass transfer coefficient equal to 0.75, 2.21 g/s and 15.08 kg/m2−s. Stage-wise evaluation of the performance shows that there is a significant improvement in the dehumidification performance by the addition of multiple stages.

Comparison of mechanical and chemical weed control in sugar beet – Impact on pest insects and epigaeic predatory arthropods

In 2019 to 2021, effects of different weed control strategies in sugar beet on pests and beneficial insects were examined at seven locations in Lower Saxony. The different strategies included conventional spraying, band spraying in the row together with mechanical hoeing between the rows and mechanical hoeing between the rows along with hand hoeing in the row. The various beneficial and pest insects were caught using different trapping methods. For the majority of arthropod populations, either no differences or hardly any significant differences were reported between the three different weed control strategies. Significant effects could only be found on single dates, but these were also not directed in the same direction. According to the results from the photoeclector catches and visual assessments, hoeing three times and chemical weed control had comparable effects to the on the arthropod populations evaluated in this study.

Challenging zircon coatings by suspension plasma spraying

Zircon is a ceramic material that decomposes at high temperature, limiting its use by conventional thermal spraying. In this work, it is intended to use thermal spraying from concentrated aqueous suspensions to evaluate the possibility of obtaining coatings in which a significant proportion of zircon could be preserved. For this purpose, stable concentrated suspensions of zircon have been prepared, which have been subsequently sprayed at two different spraying distances. The coatings were characterised in terms of microstructural features and the amount of zircon present in the coatings was quantified. All the coatings obtained display the typical microstructure derived from the deposition of liquid feedstocks by plasma spraying. In all cases, the XRD analysis demonstrates the partial decomposition of zircon into zirconia and residual silica, but also that a significant percentage (about 20%) is preserved without decomposing, which marks a strong difference with respect to reported data for atmospheric plasma spraying.

The effect of spray rails, chine strips and V-shaped spray interceptors on the performance of low planing high-speed craft in calm water

The design of spray rails has been under-reported in recent decades; besides general guidelines, few studies focus on the design of spray rails on a planing craft. The influence of the breadth and the bottom angle of the spray rails on the performance of the craft is not clear yet. Although known to naval architects, few studies of chine strips have been conducted. V-shaped spray interceptors (VSI) are a novel concept of reducing the resistance of a planing craft by deflecting the spray forward of the stagnation line. Although the VSIs have been shown to reduce the resistance of a planing craft at Fr∇ > 3.65, it is not known whether they yield the same benefits at lower planing speeds. This study presents a series of model tests of a low planing craft (Fr∇ = 1.742–3.261) equipped with different spray rails, chine strips, and a V-shaped spray interceptor (VSI). At planing speeds Fr∇ > 3, the spray rails reduced the resistance by up to 2.4%, while at semi-displacement speeds Fr∇ < 3, spray rails did not improve the performance. At Fr∇ > 3, none of the spray rails changed the trim (± 0.05°) significantly. Narrow spray rails with sharp bottom angles provided equal or better performance compared with conventional wide horizontal spray rails. Unnecessarily long spray rails increase the resistance, negating the benefits of spray deflection. Chine strips had a significant influence on the total resistance, trim and sinkage of both the bare hull and the hull equipped with spray rails. At the planing speed, chine strips reduced the running trim by up to 0.3° and the total resistance by up to 3%. However, at semi-displacement speeds, the effect of the chine strips was proportionally opposite. When the VSI was located forward of the stagnation line, it deflected the oncoming spray, thereby inducing a reaction force on its deflection surface in the direction of the craft's motion, hence reducing the total resistance by up to 4.2%. When the VSI was behind the stagnation line, it increased the total resistance by up to 8.4%.

Nozzle atomizing performance evaluation in complex environment using residual atrous spatial pyramid network

Conventional spray particle detection methods have disadvantages such as spray field interference, large subjective standard error, and an inability to specifically analyze the spray particle movement. Manual methods used the uniformity of the liquid deposit in the spray chamber to detect spray particles, which only considered the particle density information. Especially, manual detection results by different observers are significantly different, resulting in the low measurement accuracy of the spray particle size. In order to overcome these challenges, this paper proposes a non-contact spray particle segmentation based on the Residual Atrous Spatial Pyramid Network (RASPN). In the RASPN, the spray angle of the fragranced nozzle and the distribution of spray particles of different sizes are evaluated through the statistical method. The experimental results show that the proposed RASPN outperforms the compared methods in terms of detection accuracy. The injection angle is about 31° under an injection pressure of 0.4 MPa, with the highest proportion of 40–80 pixel spray particles.

The impact of carcass size, chilling, and electrical stimulation on beef postmortem temperature and pH decline

Variability in carcass size can influence carcass chilling rates which could result in issues associated with beef tenderness and color. Moreover, the usage of electrical stimulation can affect postmortem metabolism and meat quality. However, few studies have looked at the combined impact of chilling and electrical stimulation on temperature decline, postmortem biochemistry, and color among the current consist of US beef. Beef carcasses (N =162, &amp;lt; 30 months) were randomly selected from two beef processing plants. One side of each carcass was electrically stimulated (ES), while the opposing side was not electrically stimulated (NES). Matched sides were subjected to either conventional spray chilling (CONV) or delayed-spray chilling (DELAY). Deep tissue (10.5-cm under the pelvic bone) and surface temperature (1.5-cm under the loin fat) were continuously monitored during chilling in addition to temperature and pH measurements from the semimembranosus (SM), longissimus lumborum (LL), and psoas major (PM) muscles at an initial time (45 to 60 min), 6 h, 12 h, and after chilling (28 to 36 h) postmortem. Further, the instrumental (L*, a*, and b*) and visual color of the PM were evaluated. For data analysis, carcasses with hot carcass weights above or below the average were considered heavy or light, respectively. A nonlinear regression model was fitted to the continuous deep and surface temperatures, whereas other parameters were evaluated using a mixed model. Electrical stimulation improved (P &amp;lt; 0.05) the color of PM in light weight carcasses, but not (P &amp;gt; 0.05) in heavy weight carcasses. Temperature decline was faster (P &amp;lt; 0.05), and pH decline slower (P &amp;lt; 0.05) in the SM and LL of light weight carcasses under CONV. Exponential decay models for deep and surface temperatures indicated the rate of cooling differed (P &amp;lt; 0.05) due to the combination of treatment factors. Heavy weight carcasses in DELAY had slower rates of temperature decline (P &amp;lt; 0.05). Overall, the variability in carcass size affected temperature decline and postmortem metabolism. Therefore, postmortem management practices should consider carcass weights to ensure homogeneous meat quality.