Nanodiamond emulsions for enhanced quantum sensing and click-chemistry conjugation

Nanodiamonds containing nitrogen-vacancy (NV) centers can serve as colloidal quantum sensors of local fields in biological and chemical environments. However, nanodiamond surfaces are challenging to modify without degrading their colloidal stability or the NV center's optical and spin properties. Here, we report a simple and general method to coat nanodiamonds with a thin emulsion layer that preserves their quantum features, enhances their colloidal stability, and provides functional groups for subsequent crosslinking and click-chemistry conjugation reactions. To demonstrate this technique, we decorate the nanodiamonds with combinations of carboxyl- and azide-terminated amphiphiles that enable conjugation using two different strategies. We study the effect of the emulsion layer on the NV center's spin lifetime, and we quantify the nanodiamonds' chemical sensitivity to paramagnetic ions using $T_1$ relaxometry. This general approach to nanodiamond surface functionalization will enable advances in quantum nanomedicine and biological sensing.Comment: 52 pages, 42 figures (main text plus supplementary information

DETERMINATION OF REDUNDANCY IN STRUCTURES USING INTERVAL UNCERTAINTY ANALYSIS

Existence of redundancy in structures plays an important role in increasing their safety and reliability. However, using state-of-the-art deterministic and probabilistic approaches, all possibilities for estimation of redundancy (e.g. due to occurrence of different damage scenarios) have not been considered. One of the methods to quantify the presence of uncertainties in a system is to use interval variables. In this work, a new method for estimating the redundancy using interval structural analysis is developed. This method, hereafter referred to as Interval Redundancy Analysis (IRA), is robust and considers possibilities of strength reduction for each element leading to failure. Independent intervals for reduction of the strength for five damage scenarios of intact, slightly damage, moderately damaged, severely damaged, and completely damaged as well as strength of each element are considered. A numerical example to show the behavior of the developed method with comparison to Monte-Carlo simulation results is presented.M.S. in Civil Engineering, May 201

Comparison and technical evaluation of electrostatic, micronair and tractor-mounted lance sprayers in order to control (Carpocasa pomonella L) in apple orchards

Introduction The efficiency and cost effectiveness of orchard pest management programs are influenced by the skills of managers and sprayer operators who evaluate orchard conditions and alter machine settings and operating techniques to optimize performance of sprayers. A combination of operational skill, equipment performance, timing and chemical selection is necessary for optimal results. Research and development of electrostatics, air-assisted, low-volume spraying and other technologies for agriculture and horticulture was studied by biological and agricultural engineering in order to decrease of pesticide consumption. The main objective of charged liquid or powder form of the pesticide spread is increasing the percentage of poison meeting on plant surfaces. The first sprayer with rotary plate became available in 1970. The amount of solution was less and had uniform spray droplets. Apple orchards in West Azerbaijan province, Iran, are sprayed mainly with tractor-mounted lance sprayers but there is large national, regional and farm to farm variation in spray volumes applied with such sprayers. Traditionally, high spray volumes (> 2000 l.ha-1) were used in many places. Reduction in spray volume has been driven largely by the need to improve spraying equipment. West Azerbaijan province has 117000 hectare fruit orchards and 1.2 million ton fruit production that the most of them are apple and grape. However, it is necessary for reduction of pesticide application in order to produce economic and safe fruits. Materials and Methods In the present study the tractor-mounted lance sprayer in control of apple pest (Carpocasa pomonella L) was evaluated and compared with electrostatic and Micronair sprayers. This research was implemented in an apple orchard (Golden Delicious variety) with row spacing of 66 meter. The experiment was conducted as a randomized complete block design (RCBD) with three replications. Statistical analysis was performed using MS-TATC software and mean comparisons were conducted by Duncan’s multiple range test. The location of the research was in an orchard around the city of Urmia with geographical coordinates of 10-45' and 24-37' north latitude and east longitude, average rainfall of 380 mm, average temperature of 10°C, relative humidity of 60% and an average wind speed of 3.4 m.s-1. Average altitude of 1450 meters above sea level and has very high soil fertility and texture of silt loam class was the first class. In this experiment the following variables were measured: solution consumption, droplet distribution uniformity, pest control and economical comparison. Distribution uniformity was evaluated by use of water sensitive papers with dimension of 7×3 centimeter that installed in front and behind of leaves. Results and Discussion During the two-years study, results showed that uniform droplets on leaves in electrostatic and micronair sprayers with 30 drops per square centimeter were better than lance sprayer and in behind of leaves and electrostatic sprayer with 16 drops per square centimeter had better coverage. In lance type, large droplets and non-uniform distribution on the front and back of the leaves were observed. The mean comparison of solution consumption of treatments showed that electrostatic and microner sprayers with 157 and 134 liters per hectare, respectively, were in the range of low volume spraying (from 50-200 liters per hectare) and lance sprayer with 1629 liters per hectare was in the high volume spraying (more than 200 liters per hectare). Economically, the results showed that the micronair sprayer with high cost-benefit ratio (315.7) was recommended. Low volume spraying of apple trees is achievable by the use of spray technology such as micronair sprayers and provides considerable advantages in spray volume reduction. Conclusions Pesticides are active substances and instead of drenching of targets with lance sprayers we can change this poor and high expensive method with effective and environmental friendly methods. The technical evaluation showed that electrostatic and micronair sprayers were significantly better with more spray uniformity, higher performance, and lower consumption of solutions. Replacing the traditional methods with minimal use of chemicals and new equipment can improve the quality of agricultural and horticultural crops in national production contribution

Construction and evaluation of a hollow cone type nozzle with ceramic nanocomposites

Introduction: In order to improve the use of pesticides and pesticide consumption and prevent environmental pollution, manufactures and scientists have considered two major trends. The first major trend is improving techniques that are practical and effective use of small quantities of chemicals to reduce the negative effect of residues of pesticides. The use of new methods usually requires investment and cost. The second major trend is changing the parts that are more important to reform the sprayer components in order to reduce pollution, mainly by including engineering controls, and design and construction of appropriate nozzles. The optimization can be done with the least expensive pesticide. Nozzle is a device for spraying the solution in the form of particles with a certain pattern. Tip of a nozzle is placed in the nozzle’s body and has many different types. The main factors in choosing tips include: material, pattern of distribution, spray angle and the amount of the solution. The spray tip may be made of aluminum, brass, nylon, stainless steel, ceramic or other materials. Nanocomposites are composites that contain at least one component with dimensions in the nanometer range between 1 to 100 nm. This material is suitable as an alternative to overcome the limitations that exist with integrated microcomposites. The aim of this study was the construction and evaluation of a sprayer nozzle with ceramic nanocomposites with good shelf life and optimum performance. Materials and methods: This research was supported by the Agricultural Engineering Research Institute and Nanotechnology Committee of the Ministry of Agriculture. The operations of this study were as follows: 1- Preparing of materials, including alumina powder and stabilized zirconia powder with yttrium. 2- Design and manufacture of molds. 3- Preparation of the samples pressing operations. 4- Zintering of samples to achieve high density. 5- Tests to determine the quality of the products. In order to prepare nanocomposite powder mixed with stabilized zirconia alumina, the ratio of 10/90 percent by volume of the powder was poured into the mill for three hours and it was stirred in the mixer. Pressing is placing the powder into a mold, and applying pressure to achieve the desired density. In this study, pressing device with 30 tons was manually used and powder sample in the amount of one gram was placed in a semi-cylindrical small hollow. After making a few samples and determining the optimal pressure and time of pressing in action, samples were manufactured under 90 kg cm-2 pressure at 20 seconds. A high temperature furnace model F3L-1720 was used for zintering. Samples were put into the furnace after forming by a single-axis press. Temperature the of furnace was raised up 1650°C at a rate of 10 degrees per minute and then the samples were exposed for one hour in order for the heat to be evenly applied in all the body of the nozzle. Finally, a hollow cone spray pattern fan nozzle with a major diameter of 15 mm and an inner diameter of 2 mm was built. Equipment for analyzing used in this study included: X-Ray Diffraction device (XRD), Scanning Electron Microscope (SEM). The flow rate output was measured at a pressure of 2 bar in the period of 0-50 hours at 1, 2, 3, 4, 5, 8, 10, 15, 20, 25, 30, 40 and 50 hours. Results and Discussion: XRD analysis of nano-composite stabilizer in the presence of yttria- zirconia- alumina toughness with (Al2O3-ZrO2-Y2O3), yttria stabilized zirconia (ZrO2-Y2O3) and alumina indicates respective phases. For the samples made with better properties, it should be uniformly distributed within it. To evaluate the uniformity, SEM-Mapping test samples were made. The results showed that the distribution of Y, Zr, Al in nanocomposite (Al2O3-ZrO2-Y2O3) is almost uniform. The results of changes in the level of output over time showed that the rate of flow in composite (Al2O3-ZrO2-Y2O3) nozzle versus ceramic conventional (Al2O3) nozzle after 50 hours of testing under static condition, flow rate was decreased to 30- 35 percent. Conclusions: Nozzles are one of the most important terminal parts in sprayers and are used to spread the liquid evenly at a certain flow rate. Addinga nanomaterial ceramic structure as a new solution was effective. By paying attention to reduce the use of chemicals and protection of the resource bases, a correct approach to the development of agricultural mechanization equipment that are essential components should be a priorityas a low-cost solution