Volume Mean Diameter Research Articles

A predictive model of iron oxide nanoparticles flocculation tuning Z-potential in aqueous environment for biological application

Iron oxide nanoparticles are the most used magnetic nanoparticles in biomedical and biotechnological field because of their nontoxicity respect to the other metals. The investigation of iron oxide nanoparticles behaviour in aqueous environment is important for the biological applications in terms of polydispersity, mobility, cellular uptake and response to the external magnetic field. Iron oxide nanoparticles tend to agglomerate in aqueous solutions; thus, the stabilisation and aggregation could be modified tuning the colloids physical proprieties. Surfactants or polymers are often used to avoid agglomeration and increase nanoparticles stability. We have modelled and synthesised iron oxide nanoparticles through a co-precipitation method, in order to study the influence of surfactants and coatings on the aggregation state. Thus, we compared experimental results to simulation model data. The change of Z-potential and the clusters size were determined by Dynamic Light Scattering. We developed a suitable numerical model to predict the flocculation. The effects of Volume Mean Diameter and fractal dimension were explored in the model. We obtained the trend of these parameters tuning the Z-potential. These curves matched with the experimental results and confirmed the goodness of the model. Subsequently, we exploited the model to study the influence of nanoparticles aggregation and stability by Z-potential and external magnetic field. The highest Z-potential is reached up with a small external magnetic influence, a small aggregation and then a high suspension stability. Thus, we obtained a predictive model of Iron oxide nanoparticles flocculation that will be exploited for the nanoparticles engineering and experimental setup of bioassays.

Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6% dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6% db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6% db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder.

Representative Grain Size and Equivalent Roughness Height of a Sediment Bed

AbstractThe representative grain size of a sediment bed can be defined as the mean-volume diameter, which varies with the geometric standard deviation of sediment size. The obtained results explain why the representative sediment size can be approximated to be D84 for typical gravel beds. The analysis is finally extended to quantify the dependence of the equivalent sand roughness on the geometric standard deviation of grain size distribution.

Dual‐frequency radar Doppler spectral retrieval of rain drop size distributions and entangled dynamics variables

AbstractA novel technique based on Ka‐W band dual‐wavelength Doppler spectra has been developed for the simultaneous retrieval of binned rain drop size distributions (DSD) and air state parameters like vertical wind and air broadening caused by turbulence and wind shear. The rationale underpinning the method consists in exploiting the peculiar features observed in Doppler spectra caused by the wavelength dependence of scattering and absorption properties. A notional study based on a large data set of DSDs measured by a two‐dimensional video disdrometer demonstrates that the retrieval performs best for small/moderate air broadening spectral width and when mean volume diameters exceed at least 1 mm. The retrieval is also limited to ranges below cloud base and where the signal‐to‐noise ratio of both radars exceed 10 dB, which rules out regions affected by strong attenuation. Broadly speaking, it is applicable to rain rates comprised between roughly 1 and 30 mm h−1. Preliminary retrieval for observations at the Atmospheric Radiation Measurement Southern Great Plains site shows very good agreement with independent reflectivity measurements from a 0.915 GHz wind profiler. The proposed methodology shows great potential in linking microphysics to dynamics in rainfall studies.

Experimental Study on Icing and Anti-Icing Characteristics of Engine Inlet Guide Vanes

Icing and anti-icing characteristics of engine inlet guide vanes are studied in this paper. Experiments are carried out in an icing wind tunnel under different icing conditions. The tests are performed at a freestream velocity of , an inlet angle of attack of 0 deg, and a freestream static temperature in the range of . The icing environment parameters include a mean volume diameter of , liquid water content in the range of 0.5 to . The experiment is performed on full-scale inlet guide vanes. The temperature distributions on the guide vane surface are measured by thermocouples. The leading-edge ice shapes of inlet guide vanes are compared under different icing conditions. The effects of freestream static temperature, liquid water content, and the mass flow rate of anti-icing hot air on the performance of the anti-icing system are presented and analyzed.

The Effect of Reynolds Number on the Thermal and Hydrodynamic Characteristics of Turbulence Flow of the Nanofluid in the Heat Exchanger

Abstract. Reynolds number is one of the most important parameters in investigation of heat transfer in double tube heat exchangers. In this paper, the effect of this parameter has been investigated on the convective heat transfer coefficient and surface friction coefficient of the wall. Turbulent forced convection heat transfer of nanofluid flow of Al 2 O 3 /water in a double tube heat exchanger with rough tubes in the annular portion was numerically studied. The finite volume method and the second-order upstream difference scheme were used for the discretization of the governing equations. The volume fraction and mean diameter of nanoparticles were assumed to be 4% and 32 nm, respectively. After reviewing the results, it was observed that the convective heat transfer coefficient in the outer and inner walls of heat exchanger increases with the increase of the Reynolds number. The wall surface friction coefficient, which decreases by increasing Reynolds number, is another examined parameter.

Turbulent Mixing in Shallow Trade Wind Cumuli: Dependence on Cloud Life Cycle

Abstract Helicopter-borne observations of the impact of turbulent mixing and cloud microphysical properties in shallow trade wind cumuli are presented. The measurements were collected during the Cloud, Aerosol, Radiation and Turbulence in the Trade Wind Regime over Barbados (CARRIBA) project. Basic meteorological parameters (3D wind vector, air temperature, and relative humidity), cloud condensation nuclei concentrations, and cloud microphysical parameters (droplet number, size distribution, and liquid water content) are measured by the Airborne Cloud Turbulence Observation System (ACTOS), which is fixed by a 160-m-long rope underneath a helicopter flying with a true airspeed of approximately 20 m s−1. Clouds at different evolutionary stages were sampled. A total of 300 clouds are classified into actively growing, decelerated, and dissolving clouds. The mixing process of these cloud categories is investigated by correlating the cloud droplet number concentration and cubed droplet mean volume diameter. A significant tendency to more inhomogeneous mixing with increasing cloud lifetime is observed. Furthermore, the mixing process and its effects on droplet number concentration, droplet size, and cloud liquid water content are statistically evaluated. It is found that, in dissolving clouds, liquid water content and droplet number concentration are decreased by about 50% compared to actively growing clouds. Conversely, the droplet size remains almost constant, which can be attributed to the existence of a humid shell around the cloud that prevents cloud droplets from rapid evaporation after entrainment of premoistened air. Moreover, signs of secondary activation are found, which results in a more difficult interpretation of observed mixing diagrams.

Effect of high speed jet on the physical properties of tapioca starch

Tapioca starch-water suspension was subjected to high speed jet (HSJ) treatment and the physical properties were investigated by Particle size analysis, Differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). Particle size analysis revealed a significant increase in volume mean diameter from 17.00 to 40.35 μm. SEM studies showed that treated tapioca starch (TS) was prone to aggregate with each other and markedly damaged at starch granule surface which eventually disintegrated into gel-like structures at high pressure level. XRD patterns showed that all samples exhibited A-type and there was an evident loss of crystallinity after treated over 160 MPa. The TS showed similarity on FTIR spectral pattern but had different intensity in some peaks at increasing pressure. DSC analysis confirmed that TS was partly gelatinized after HSJ treatment, and the degree of gelatinization increased to 34.34 ± 1.0% when the pressure was 240 MPa. These results provided the basic information on the physical properties of TS treated at different pressures and indicated the potential possibility of HSJ for starch modification.

The effect of blending Jersey and Holstein–Friesian milk on composition and coagulation properties

The impact of blending on milk composition and properties is subject to controversy on whether the effect is additional or not. The effects of blending Jersey and Holstein–Friesian milk on composition and coagulation properties were investigated. Milk from herds of Jersey and Holstein–Friesian cattle was collected and blended (0–100% Jersey milk at 10% intervals) (n = 55).Including Jersey milk resulted in a positive non‐additive effect in fat globule volume mean diameter D(4.3) and a negative non‐additive effect in casein micelle size. Coagulation time decreased quadratically when Jersey milk was added and curd firmness and firming rate increased quadratically.

Creeping Flow of Viscoelastic Fluid Through a Packed Bed: Effect of Particle Shape and Porosity

Experiments were conducted to elucidate the effect of particle shape and porosity on frictional pressure drop for the flow of viscoelastic fluids through a packed bed under creeping flow regime. Extensive pressure drop-flow rate data were generated using different packing materials such as cylinders of different aspect ratios, square plates, triangles, and spheres covering a wide range of sphericity, 0.546 ≤ φ ≤ 1. Effect of bed porosity has been determined using uniform-size spheres of different diameters (4.38 mm, 5.76 mm, and 6.78 mm), covering column to particle diameter ratio in the range of 13.96–21.62; while porosity varies in the range of 0.345–0.375. The experimental results indicate that the modified Ergun correlation, proposed by Sobti and Wanchoo (2014), can adequately be applied for the nonspherical particles, provided the equivalent volume mean diameter (Deq) together with sphericity (φ) is used instead of the diameter of the spherical particle (Dp), i.e., Dp = Deqφ. Further, an attempt has been made to suitably define a packing structure parameter, [(1 − ϵ)/(ϵ φ)], which could well capture the balancing effect between porosity and sphericity.

Poly-(lactic-co-glycolic-acid)-based particulate vaccines: Particle uptake by dendritic cells is a key parameter for immune activation

Poly(lactic-co-glycolic acid) (PLGA) particles have been extensively studied as biodegradable delivery system to improve the potency and safety of protein-based vaccines. In this study we analyzed how the size of PLGA particles, and hence their ability to be engulfed by dendritic cells (DC), affects the type and magnitude of the immune response in comparison to sustained release from a local depot. PLGA microparticles (MP, volume mean diameter≈112μm) and nanoparticles (NP, Z-average diameter≈350nm) co-encapsulating ovalbumin (OVA) and poly(I:C), with comparable antigen (Ag) release characteristics, were prepared and characterized. The immunogenicity of these two distinct particulate vaccines was evaluated in vitro and in vivo. NP were efficiently taken up by DC and greatly facilitated MHC I Ag presentation in vitro, whereas DC cultured in the presence of MP failed to internalize significant amounts of Ag and hardly showed MHC I Ag presentation. Vaccination of mice with NP resulted in significantly better priming of Ag-specific CD8+ T cells compared to MP and OVA emulsified with incomplete Freund's adjuvant (IFA). Moreover, NP induced a balanced TH1/TH2-type antibody response, compared to vaccinations with IFA which stimulated a predominant TH2-type response, whereas MP failed to increase antibody titers. In conclusion, we postulate that particle internalization is of crucial importance and therefore particulate vaccines should be formulated in the nano- but not micro-size range to achieve efficient uptake, significant MHC class I cross-presentation and effective T and B cell responses.

Impact of Surgical Ventricular Restoration on Cardiac Function, Ischaemic Mitral Regurgitation and Long-term Survival

Objectives: Adverse cardiac remodelling is a major cause of morbidity and mortality post myocardial infarction. The role of surgical ventricular restoration compared to medical and electrophysiological treatments has recently come under intense scrutiny. We aimed to evaluate 10-year clinical outcomes of surgical ventricular restoration in our institution. Methods: From January 2001 to 2011, surgical ventricular restoration was performed in 126 consecutive patients (M2.3: 1F), mean age 65.5 (44-86) years. All patients presented with angina, heart failure and/or ventricular tachycardia. Post-infarction left ventricular aneurysm was present in all patients and ischemic dilated cardiomyopathy with a large akinetic left ventricle in 11.6%. The preoperative left ventricular ejection fraction was 33.1 ± 8.9%. Multi-vessel disease was present in 117/126(93%) patients. Mitral regurgitation more than grade+2 was found in 39/126(31%). The mean Logistic EuroSCORE was 13.8 ± 5.9%. A minimum of two-year post-operative follow-up was obtained on all patients. Results: Most patients underwent endoventricular or elliptical patch repair; 94% had concomitant coronary revascularisation with a median of 2 grafts and 5% had mitral valve repair. Intra-aortic balloon pump was placed preoperatively in 24/126 (19%) patients while 21/126 (17%) needed inotropic support for more than 24 h. Postoperative stroke occurred in 2 patients. In-hospital mortality was 7/126 (5.5%). All cause cardiovascular mortality at ten years was 12/126 (9.5%). Mean follow-up in operative survivors was 8.2 ± 1.2 years. Actuarial survival was 95.3%, 90.6%, 86.3% and 79.1% at 1-month, 1, 5 and 10-years. Echocardiographic follow-up demonstrated a reduction in the mean left ventricular end-diastolic volume and left atrial diameter. Ejection fraction improved over first year from 33.1 ± 8.9 to 45 ± 8.6% (P<0.006). Conclusions: Left ventricular reconstruction surgery is a good surgical option for treatment of post-infarction left ventricular aneurysm.

Characteristics of the raindrop distributions in RICO shallow cumulus

Abstract. The physical properties of rain spectra are generally modeled using an analytical distribution. It is common for the gamma distribution and, to a lesser extent, the lognormal distribution to be used. The majority of studies in the literature focusing on the characterization of raindrop distribution are based on deep convective cloud observations, mostly at ground level. This study focuses on shallow-cumulus rain distributions throughout the depth of the cloud layer and subcloud layer using airborne in situ measurements made with both the Particle Measuring Systems (PMS) Optical Array Probe 260X (OAP-260-X) and the PMS two-Dimensional Precipitation (2DP) instruments during the Rain in Cumulus over the Ocean (RICO) field experiment. Sampled spectra analyzed on the scale of large-eddy simulation resolution (100 m) are found to be relatively broad, with values of the shape parameter – υ for the gamma law and σg for the lognormal law – on the order of 1–3 and 1.5–2, respectively. The dependence of the shape parameters on the main rain variables (number concentration, water content, mean volume diameter, sedimentation fluxes and radar reflectivity) is examined, and a parameterization of the shape parameters υ and σg as a function of a power law of the rainwater content and raindrop number concentration is proposed.

Pontas de pulverização de jato cônico vazio, em função das pressões de trabalho

The spray nozzles are responsible for the design produced by the liquid sprayer and is of fundamental importance for the technology of application of pesticides, influencing variation in application rate per area. The objective of this study was to evaluate hydraulic spray nozzles hollow cone JA-1, JA-2, JA-5 and TVI 8003, under working pressures of 420, 630 and 1000 kPa. The tests of uniform volumetric distribution and characterization of the population of drops were carried out in two stages: the first stage for obtaining the distribution profile used a patternator with a height of 0,50m, the second stage was performed characterization of the droplet spectrum from the following parameters: mean volume diameter (MVD), droplet density (DD), relative amplitude (RA) and drift potential risk (DPR). The hollow cone nozzles have irregular profiles, depending on the nominal flow. A uniform volumetric distribution of the nozzles was evaluated influenced by fluid pressure and nominal flow. The hollow cone nozzles showed highly variable volumetric distribution when subjected to working pressures. All nozzles studied criteria should be used to present risk problems will drift. The air induction nozzles showed the lowest droplet density.

Influence of Cryogenic and Ambient Grinding on Grinding Characteristics of Fenugreek Powder: A Comparative Study

Grinding characteristics of fenugreek (cv. AM-1) were carried out at cryogenic and ambient conditions. It was observed that it affected average particle size, volume surface mean diameter, mass mean diameter, volume mean diameter, specific surface of mixture, number of particles per gram, energy constants – Rittinger and Kick's – and specific energy consumption. Values of average particle size, volume surface mean diameter, mass mean diameter, volume mean diameter, specific surface of mixture, number of particles per gram, Rittinger's constant, Kick's constant and specific energy consumption varied from 0.31 to 0.80, 0.31 to 0.57, 0.27 to 0.77, 0.25 to 0.41 mm; 16,413 to 34,254 mm2/g; 5,863 to 111,620 particles per gram, 4.97 to 35.87 kWh/t, 4.76 to 53.59 kWh/t, and 8.37 to 50.17 kWh/t, respectively, in the moisture content range of 5–15% wet basis at ambient and cryogenic grinding. Comparative study had shown that ambient grinding needs more power and specific energy than cryogenic grinding. Practical Applications The grinding characteristics of fenugreek powder will be useful to control the processing parameters and it will lead to improved quality and output of the fenugreek powder. The present study on grinding characteristics of fenugreek powder provides reliable information for design of equipments for handling, processing, packaging and transportation of ground powder, which will in turn be economically helpful for powder processing industries. The better color parameters of the fenugreek powder also cause enhancement of economy that may be seen with the help of present work.

알루미늄 분진의 평균입경 변화에 따른 폭발위험성

본 연구에서는 알루미늄 분말의 입자 크기에 따른 폭발특성을 20 L 분진폭발실험장치(K<TEX>$\ddot{u}$</TEX>hner제작)를 사용하여 조사하였다. 사용한 시료는 각각 16, 33, <TEX>$88{\mu}m$</TEX>의 체적기준 평균입경을 갖는 알루미늄 입자를 대상으로 실험을 수행하였다. 분진의 평균입경이 16, 33, <TEX>$88{\mu}m$</TEX>에서 폭발하한농도는 각각 40, 60, <TEX>$125g/m^3$</TEX>로서 분진의 입경이 증가하면 점차적으로 증가하는 경향을 나타냈다. 또한 각각의 알루미늄 분진에서 입자 크기의 증가는 폭발압력 및 분진폭발지수(<TEX>$K_{st}$</TEX>)의 감소로 이어졌다. 이러한 본 연구 결과는 알루미늄 분말의 활용 및 안전 운전을 위한 중요 자료로 활용될 수 있다. In this study, the explosion characteristic of aluminium powders have been investigated as a function of particle size using by a 20 L dust explosion apparatus (K<TEX>$\ddot{u}$</TEX>hner). The tested aluminium particle sizes were the volume mean diameter of 16, 33 and <TEX>$88{\mu}m$</TEX>. The lower explosion limit increases gradually with the increasing of dust particle diameter, respectively 40, 60, <TEX>$125g/m^3$</TEX> in mean diameter of 16, 33 and <TEX>$88{\mu}m$</TEX>. Also the increase in particle size for each aluminum dusts was found to cause an decrease in explosion pressure and Kst of dust explosion index, and a increase in the lower explosion concentration. Research results may have important implications for aluminum powders utilization and safety operation.

The influence of LiDAR pulse density on the precision of inventory metrics in young unthinned Douglas-fir stands during initial and subsequent LiDAR acquisitions

LiDAR is an established technology that is increasingly being used to characterise spatial variation in stand metrics used in forest inventory. As the cost of LiDAR acquisition markedly declines with LiDAR pulse density, it is useful to identify how far pulse density can be reduced without compromising the precision of relationships between LiDAR and stand metrics. Using plot measurements and LiDAR data obtained from highly stocked and unthinned Douglas-fir plantations (Pseudotsuga menziesii [Mirb.] Franco), the objective of this research was to characterise the precision of regressions between LiDAR metrics and stand metrics (mean top height, Hm, volume, V and mean diameter, D) under a range of pulse densities using Digital Terrain Models (DTMs) representing two common scenarios. Under the first scenario, which represents an initial acquisition, the point cloud was sequentially culled and used for creation of a DTM and corresponding LiDAR cloud metrics. In the second scenario, which represents a subsequent acquisition, a DTM generated at high pulse density (10 pulses m−2) was used for the creation of the corresponding LIDAR cloud metrics. Models describing the precision of regressions between LiDAR metrics and stand metrics were developed at 10 pulses m−2. LiDAR data were culled to pulse densities ranging from 10 to 0.01 pulses m−2 and the impact of culling on the precision of these regressions was examined under the two scenarios. For the scenario with the culled DTM, precision of the three models remained stable until densities of 2 – 3 pulses m−2 were reached. Below this threshold, there was a gradual decline in precision to pulse densities of 0.7 – 1 pulses m−2 at which point the R2 was 95% of the maximum values. Further culling of the data resulted in a sharp decline in model precision for all three regressions. For the scenario where the DTM was held at a high pulse density, little change in the precision of the regressions was found until pulse densities of 0.04 to 0.2 pulses m−2 were reached. There was a sharp decline in precision below pulse densities of 0.04 pulses m−2 for all three models. This study was undertaken in highly stocked unthinned Douglas-fir stands located in areas with complex topography. Consequently, the pulse density thresholds described here are likely to be conservative and could be used to guide acquisition of high-quality LiDAR datasets for this species.

Physicochemical and acid gelation properties of commercial UHT-treated plant-based milk substitutes and lactose free bovine milk

Physicochemical and acid gelation properties of UHT-treated commercial soy, oat, quinoa, rice and lactose-free bovine milks were studied. The separation profiles were determined using a LUMiSizer dispersion analyser. Soy, rice and quinoa milks formed both cream and sediment layers, while oat milk sedimented but did not cream. Bovine milk was very stable to separation while all plant milks separated at varying rates; rice and oat milks being the most unstable products. Particle sizes in plant-based milk substitutes, expressed as volume mean diameters (d4.3), ranged from 0.55μm (soy) to 2.08μm (quinoa) while the average size in bovine milk was 0.52μm. Particles of plant-based milk substitutes were significantly more polydisperse compared to those of bovine milk. Upon acidification with glucono-δ-lactone (GDL), bovine, soy and quinoa milks formed structured gels with maximum storage moduli of 262, 187 and 105Pa, respectively while oat and rice milks did not gel. In addition to soy products currently on the market, quinoa may have potential in dairy-type food applications.

Shipborne Polarimetric Weather Radar: Impact of Ship Movement on Polarimetric Variables at C Band

Abstract The effect of ship motion on shipborne polarimetric radar measurements is considered at C band. Calculations are carried out by (i) varying the “effective” mean canting angle and (ii) separately examining the elevation dependence. Scattering from a single oblate hydrometeor is considered at first. Equations are derived (i) to convert the measured differential reflectivity for nonzero mean canting angles to those for zero mean canting angle and (ii) to do the corresponding corrections for nonzero elevation angles. Scattering calculations are also performed using the T-matrix method with measured drop size distributions as input. Dependence on mean volume diameter is examined as well as variations of the four main polarimetric parameters. The results show that as long as the ship movement is limited to a roll of less than about 10°–15°, the effects are tolerable. Furthermore, the results from the scattering simulations have been used to provide equations for correction factors that can be applied to compensate for the “apparent” nonzero canting angles and nonzero elevation angles, so that drop size distribution parameters and rainfall rates can be estimated without any bias.

Aerosol Performance and Long-Term Stability of Surfactant-Associated Liposomal Ciprofloxacin Formulations with Modified Encapsulation and Release Properties

Previously, we showed that the encapsulation and release properties of a liposomal ciprofloxacin formulation could be modified post manufacture, by addition of surfactant in concert with osmotic swelling of the liposomes. This strategy may provide more flexibility and convenience than the alternative of manufacturing multiple batches of liposomes differing in composition to cover a wide range of release profiles. The goal of this study was to develop a surfactant-associated liposomal ciprofloxacin (CFI) formulation possessing good long-term stability which could be delivered as an inhaled aerosol. Preparations of 12.5 mg/ml CFI containing 0.4% polysorbate 20 were formulated between pH 4.7 and 5.5. These formulations, before and after mesh nebulization, and after refrigerated storage for up to 2 years, were characterized in terms of liposome structure by cryogenic transmission electron microscopy (cryo-TEM) imaging, vesicle size by dynamic light scattering, pH, drug encapsulation by centrifugation-filtration, and in vitro release (IVR) performance. Within the narrower pH range of 4.9 to 5.2, these formulations retained their physicochemical stability after 2-year refrigerated storage, were robust to mesh nebulization, and formed respirable aerosols with a volume mean diameter (VMD) of 3.7 μm and a geometric standard deviation (GSD) of 1.7. This study demonstrates that it may be possible to provide a range of release profiles by simple addition of surfactant to a liposomal formulation post manufacture, and that these formulations may retain their physicochemical properties after long-term refrigerated storage and following aerosolization by mesh nebulizer.