Physicochemical characterisation of inhalation grade lactose after the removal of intrinsic fines

Lactose is a common excipient in Dry Powder Inhaler (DPI) formulations, used as a carrier for the micronized drug particles. The presence of intrinsic lactose fines in the formulation influences its performance and their role and interactions between the lactose carrier and the micronized drug is still not fully understood. As a first step towards this investigation, “clean” lactose, with removed fines, was produced via wet decantation. Ethanol and isopropyl alcohol have been used in wet decantation, successfully removing lactose fines from the surface of the coarse particles. Differential Scanning Calorimetry (DSC) was employed to show that the powders maintained their crystalline character. Scanning Electron Microscopy (SEM) showed tomahawk-shaped particles in all the powders and some surface alteration occurring after decantation. An airflow titration method using laser diffraction (LDA) allowed the estimation of the removal of fines as well as the particle size distributions, while the non-polar and the polar components of the surface energy of the powders were calculated via Inverse Gas Chromatography-Surface Energy Analysis (iGC-SEA). As both solvents successfully removed fines, we propose the addition of isopropyl alcohol in the list of organic solvents suitable for this purpose.Peer reviewe

Thermal Analysis of High Pressure Micro Plasma Discharge

High pressure micro plasma discharge has been at the center of interest in recent years, because of their vast applications, ease of access and cost efficiency. This attributes to atmospheric discharges that are generated in ambient conditions and therefore can be readily applicable to everyday use. The absence of vacuum makes these high pressure discharges to be inexpensive to operate. Despite the ease of operation, the high pressure is a source of enhanced gas heating as the gas temperature cannot be controlled by diffusion alone. Gas heating is therefore an important factor when it comes to the simulation of high pressure micro plasma discharge, unlike their low pressure counterpart where the heat generation is almost negligible. Low pressure discharge due to their low degree of collisionality generates ionic species and electrons at small concentrations, whereas high pressure discharge due to their higher gas density produces ions and electrons at higher concentrations which is a direct consequence of increase collision. The higher gas density and consequential large concentration of ionic species and electron contributes directly to higher heat generation rates. . In this thesis the gas temperature transport In this thesis the gas temperature transport of high pressure micro plasma discharge has been studied with a special focus on the heat source terms, temperature boundary conditions, temperature distribution in the solid phase electrodes and the gas phase and their overall influence on the plasma characteristics. For this purpose a multi-physics mathematical model has been developed that comprised of a plasma module, neutral gas temperature module, external circuit module and conjugate heat transfer module. The plasma module consisted of conservation of the different ionic, electronically excited species, radicals, neutrals and electrons, conservation of the electron temperature, and electric field. The external circuit module resolved the coupled driving circuit comprised of a voltage source, ballast resistor and capacitance. A detailed gas phase chemical kinetic model was also implemented. One-dimensional simulation has been performed to study the effects of the neutral gas temperature on a micro plasma discharge operating in the “abnormal” glow mode. In addition, two dimensional simulation has been conducted to simulate the “normal” glow regime of a micro plasma discharge that has multi-dimensional spatial dependence. The effects of conjugate heat transfer on the gas temperature distribution and the overall plasma characteristics i.e. the voltage-current curve and electron number density has been investigated. The conjugate heat transfer is found to significantly affect the plasma behavior. Finally a temporally varying temperature boundary condition has been proposed that reduces the computational overhead but resolves the conjugate heat transfer effect with reasonable accuracy

Effects of sorghum residue in presence of pre-emergence herbicides on emergence and biomass of Echinochloa colona and Chloris virgata

In conservation agriculture systems, farmers gain many advantages from retaining crop residue on the soil surface, but crop residue retention in these systems may intervene with the activity of pre-emergence herbicides. A pot study was conducted to evaluate the effect of different rates of pre-emergence herbicides [imazethapyr (100 and 150 g a. i. ha-1), isoxaflutole (100 and 200 g a. i. ha-1), metolachlor (1.5 and 2.25 kg a. i. ha-1), pendimethalin (2.25 and 3.38 kg a. i. ha-1) and prosulfocarb + metolachlor (2.5 and 3.75 kg a. i. ha-1)] on seedling emergence and biomass of Echinochloa colona and Chloris virgata when applied in the presence of sorghum residue at rates equivalent to (0, 3 and 6 t ha-1). When seeds of E. colona and C. virgata were not covered with sorghum residue, the seedling emergence and biomass of both weeds was inhibited by 93–100% and 56–100%, respectively, with the application (both rates) of isoxaflutole, metolachlor, pendimethalin and prosulfocarb + metolachlor. Using sorghum residue resulted in lower herbicide efficacy on both weeds. At 3 t ha-1 sorghum residue, E. colona emergence and biomass reduced by 38–100% and 30–100%, respectively, with application of isoxaflutole, metolachlor and pendimethalin (both rates) in comparison with the no-herbicide treatment. Similarly, the emergence and biomass of C. virgata was also reduced by 92–100% and 25–100%, respectively. The results of this study suggest that crop residue may influence efficacy of commonly used pre-emergence herbicides and that the amount of crop residue on the soil surface should be adjusted according to the nature of the pre-emergence herbicides to achieve adequate weed control

Reducing seed dependent variability of non-uniformly sampled multidimensional NMR data

The application of NMR spectroscopy to study the structure, dynamics and function of macromolecules requires the acquisition of several multidimensional spectra. The one-dimensional NMR time-response from the spectrometer is extended to additional dimensions by introducing incremented delays in the experiment that cause oscillation of the signal along “indirect” dimensions. For a given dimension the delay is incremented at twice the rate of the maximum frequency (Nyquist rate). To achieve high-resolution requires acquisition of long data records sampled at the Nyquist rate. This is typically a prohibitive step due to time constraints, resulting in sub-optimal data records to the detriment of subsequent analyses. The multidimensional NMR spectrum itself is typically sparse, and it has been shown that in such cases it is possible to use non-Fourier methods to reconstruct a high-resolution multidimensional spectrum from a random subset of non-uniformly sampled (NUS) data. For a given acquisition time, NUS has the potential to improve the sensitivity and resolution of a multidimensional spectrum, compared to traditional uniform sampling. The improvements in sensitivity and/or resolution achieved by NUS are heavily dependent on the distribution of points in the random subset acquired. Typically, random points are selected from a probability density function (PDF) weighted according to the NMR signal envelope. In extreme cases as little as 1% of the data is subsampled. The heavy under-sampling can result in poor reproducibility, i.e. when two experiments are carried out where the same number of random samples is selected from the same PDF but using different random seeds. Here, a jittered sampling approach is introduced that is shown to improve random seed dependent reproducibility of multidimensional spectra generated from NUS data, compared to commonly applied NUS methods. It is shown that this is achieved due to the low variability of the inherent sensitivity of the random subset chosen from a given PDF. Finally, it is demonstrated that metrics used to find optimal NUS distributions are heavily dependent on the inherent sensitivity of the random subset, and such optimisation is therefore less critical when using the proposed sampling scheme

Design and calibration of a fuel consumption measurement system for a diesel tractor

 One of the best methods to measure fuel consumption of a tractor engine is using flow meter sensors on the tractor. In this study, a system for measuring fuel consumption was designed. The measurement system was installed on the engine of a 72.3 KW John Deere 3140 tractor. In this system, an electronic board was used to receive and save digital pulses sent by the flow meter sensors. One of the sensors was installed where fuel enters the injector pump, another flow meter was located where fuel returns to the tank. Accuracy of sensors in both the laboratory test and when working in field conditions were compared. Some capabilities of the system are:  measuring fuel consumption of the engine in temporal or local circumstances, showing instantaneous fuel consumption, and easy installation without significant effects on the engine under common working conditions. Keywords: Fuel consumption, Sensor, Flow meter, Tractor, Engineering  &nbsp

Effect of plant growth regulators on two different types of eggplant flowers regarding style length and fruit setting

Aim of study: (i) to explore differences between eggplant flowers capable of setting fruit including long (LGs) and medium style flowers (MEs) and those which suffer from severe problems with fertility and fruit setting including short style ones (SRTs); (ii) to study the effect of plant growth regulators on floral morphology and fruit setting. Area of study: Isfahan University of Technology, Isfahan, Iran, 2017 and 2018. Material and methods: First the floral morphology and initial fruit setting of 13 eggplant genotypes from Iran were investigated. Then the differences between LGs and SRTs of two genotypes were explored. Finally, the effect of 1-naphthaleneacetic acid (NAA) and spermidine (Spd) on floral morphology and initial and final fruit setting of these two genotypes was determined. Main results: Results showed SRTs were not capable of fruit setting. Compared to SRTs, LGs had larger central canals, higher protein, total sugar, reducing sugar and K concentrations, as well as longer polar axis and pollen tubes and greater pollen viability. Although 1.5 mM Spd and 20 mg L-1 NAA resulted in increasing of LGs and MEs, and also total initial fruit set, surprisingly, no significant differences were observed in the final yield and final fruit set between the control and these treatments. Researching highlights: Since the rate of fruit dropping was higher in those treatments compared to the control, plants with more SRTs likely regulate their final load by abscising their flowers, and plants with more LGs regulate them by abscising their fruits

Modified Atmosphere Packaging: A Progressive Technology for Shelf-Life Extension of Fruits and Vegetables

Packaging and storage are the final phases in the food industry. Quality preservation, improving safety and reduction of postharvest losses waste are some objectives of the packaging engineering. One of techniques that widely used in packaging of fruits and vegetables are modified atmosphere packaging (MAP). In MAP for fresh fruits and vegetable the air of packaging headspace replaces with a predetermined atmospheric gases different in proportion from that of air. Oxygen, carbon dioxide and nitrogen are the main gases used in MAP for injection to the headspace of pack. The choice and ratio of gases are very dependent upon the material that being packed. respiration rate of crop, O2 and CO2 permeability of package material, volume of headspace present inside the package and storage temperature are some factors that affect the quality of MA packaging. Polymeric films are widely used in MAP engineering. The most application of polymeric films for MAP are in flexible package structures. In many cases the plastic packaging films are combined with one another or with other materials such as paper or aluminum through coating, lamination, coextrusion and metallization processes. The equipment used in MAP is divided into two main categories: pillow wrap and chamber. Flexible pillow wrapping machines are composed of Horizontal Form-Fill-Seal (HFFS) machines and Vertical Form-Fill-Seal (VFFS) systems. This paper reviews some recent developments in MAP technology applied for fruits and vegetables

On-site measurement of soil moisture content using an acoustic system

Precision agriculture is a farming management concept based on observing and responding to intra-field variations.  One of the most important soil properties in farming is soil moisture content and it is necessary to develop new technique for measuring this property in a precision farming system.  This study investigates the measurement of moisture content in soil using an on-site, easy to use and real-time acoustic wave system.  The system consists of the propagation of acoustic waves such as sweep frequency sound wave (10-300 Hz) and multiple tone sound waves (120 Hz) through the soil.  Some properties of these acoustic waves enable estimation of soil water content such as peak amplitude (A), total power (TP), total harmonic distortion (THD) and signal to noise ratio (SNR).  The results showed that the best model for estimating the soil moisture content was the model that expressed relationship between A and soil moisture content with R2 = 0.999 (using sweep frequency) and relationship between TP and soil moisture content with R2 = 0.999 (using multiple tone).  It is argued that the change in the sound characteristics related to the soil moisture content can be used for a continuous monitoring and control of irrigation of crops.   Keywords: acoustic waves, soil moisture content, sound propertie