Constituent Powders Research Articles

Detection of Organic Explosive Residues from Outdoor Detonations using Confocal Raman Microscopy

The detection of post-blast residues in the aftermath of an explosion involving organic explosives with spectroscopic techniques is challenging as, typically, no microscopically visible unreacted particles remain after the explosion. However, some low-order explosions may leave visible particles behind, as well as the presence of significant amounts of unreacted material. In this study, four authentic open-air detonations using two simulated improvised explosive devices (IEDs) containing a mixture of military explosives (TNT and RDX), and two IEDs containing smokeless powder were conducted. The various materials they contained, including plastic, wood, and metal, were swabbed and extracted with acetone to create post-blast liquid extracts. The extracts were then dried and examined using confocal Raman microscopy, alongside a 50 ppm reference mixture of smokeless powder constituents, which was created to evaluate the effects of Raman scattering within the full smokeless powder mixture. Smokeless powder constituents, such as ethyl centralite, diphenylamine, nitroglycerin, and dibutyl phthalate, were successfully identified by comparison to the reference mixture on most substrates, with the exception of the paint stick (wood) substrate. TNT/RDX was also able to be identified in the extracts, with RDX crystals being observed in some dried extracts after solvent evaporation. However, the detection of TNT/RDX in the second detonation was unsuccessful, possibly due to an explosive chain reaction that was highly efficient. No trends were seen in substrate affinity for TNT/RDX. The challenges and benefits with the developed methodology for the detection of organic explosive residues from a variety of substrates are discussed in detail.

Detection of explosives residue using a novel subsampling technique for DART-HRMS analysis

In the ensuing investigation after an explosion, determining the explosive used is of prime importance to establish investigative leads. Post-blast samples have many interferences and considerations that make quick, reliable identification a challenge. The use of a novel subsampling technique with DART-HRMS provides the ability to quickly detect and identify explosive residue after detonation. Simulated improvised explosive devices were constructed with a variety of materials and detonated with the help of the Montgomery County Fire Marshal’s Office (TX). Post-blast debris was subsequently collected and swabbed with a novel subsampling technique, utilizing filter paper. This filter paper was then introduced into the DART gas stream, with an internal standard to minimize potential false negatives. After introducing explosive residue from swabbed post-blast substrates, characteristic ions of selected constituents of smokeless powder including diphenylamine, ethyl centralite, di-n-butyl phthalate, and nitroglycerin were detected and confirmed through comparison of accurate mass measurements to theoretical exact masses. Additionally, characteristic ions of 2,4,6-trinitrotoluene (TNT) and Royal Demolition eXplosive (RDX) were also detected using this technique. Overall, the detection of characteristic ions was more successful when recovering residue from plastic compared to wood or metal, with success rates routinely at 100%. Implementing this screening technique enables rapid detection and reliable identification of explosive residue in a detonation incident. The developed subsampling technique provides practitioners with a practical method of screening post-blast debris in a laboratory setting, requiring minimal sample preparation.

The Protective Activity of Withania somnifera Against Mercuric Chloride (HgCl2)-Induced Renal Toxicity in Male Rats.

The purpose of this study was to test the protective effect of Withania somnifera (WS) against the harmful effects of mercuric chloride (HgCl2)-induced kidney failure at the histological, biochemical, and immune levels in Wistar rats. The study assessed the biochemical and immunological changes in five groups (n = 6): Group 1 (G1) was the negative control, and the other rats received a single subcutaneous dose of HgCl2 (2.5 mg/kg in 0.5 mL of 0.9% saline solution) and randomly divided into 4 groups. Group 2 (G2) was the positive control and left without treatment. Groups 3, 4, and 5 (G3, G4, and G5) were treated with different doses of WS root powder for 30 days. The HgCl2-positive group showed significant signs of renal toxicity as reflected by increased levels of kidney function parameters (blood urea nitrogen, urea, and creatinine), inflammatory biomarkers, immunological indices (SDF-1, IL-6, NGAL, and KIM-1), and oxidative stress (SOD, TAC, CAT, GSH, and MDA). The positive group rats also showed drastic pathological changes in renal tissues. Different doses of WS treatment significantly reduced the levels of all biochemical markers and decreased pathological damage to the kidney tissues. The antioxidant, phenolic, and flavonoid constituents of WS root powder helped protect rats' kidneys against HgCl2-induced kidney toxicity in male rats.

Investigating the combined capability of confocal Raman microscopy and direct analysis in real time-mass spectrometry (DART-MS) for the analysis of intact explosives

The identification of organic and inorganic components used to produce homemade explosives (HMEs) remains a challenge for forensic analysts due to their diverse physicochemical properties that require different instrumentation. This study aims to explore the combined use of direct analysis in real time-mass spectrometry (DART-MS) and Raman microscopy to provide a rapid and reliable analysis of a variety of intact explosives with minimal sample preparation, including 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), seven inorganic oxidizing salts, and five smokeless powder constituents. While both techniques were well-suited for the analysis of TNT and PETN, DART-MS had the advantage of being more sensitive compared to Raman spectroscopy for the identification of the organic components contained in smokeless powder. Even though the identification of ammonium-based salts using DART-MS could be achieved, the analysis of low-volatility compounds, such as the inorganic oxidizing salts, was more straightforward with Raman microscopy and did not require sample preparation. This study demonstrates the benefits and limitations of combining Raman microscopy and DART-MS for the analysis of intact explosives and precursors. Using this combined approach enabled the rapid identification of various organic and inorganic explosives and precursors with minimal sample preparation.

Characterisation and phytochemical profile of sunlight exposed freeze-dried oyster mushroom (Pleurotus ostreatus) powder

Mushrooms are vitamin B and D rich fungi which belong to the division Basidiomycota. Oyster mushroom (Pleurotus ostreatus) has distinct flavour, contains high nutrients and phytochemicals. Phytochemicals are naturally existing compounds which play with nutrients to protect against diseases. The aim of the study is to characterise and compare the phytochemical profile of sunlight exposed freeze-dried oyster mushroom (SEFDOM) powder and non-sunlight exposed freeze-dried oyster mushroom (NSEFDOM) powder. The phytochemical constituents of both SEFDOM and NSEFDOM powder were extracted using aqueous, methanol and ethanol. Eighteen metabolites were screened for all the three solvents for both the samples. The phytochemical screening showed that the presence of alkaloids, flavonoids, sterols, proteins, carbohydrates, saponins for both samples were detected while other remaining metabolites were not detected. The results showed that the metabolites such as alkaloids, sterols, anthraquinones and carbohydrates were appreciable in the NSEFDOM powder group when compared to SEFDOM powder samples. Protein content was found to be high in SEFDOM powder group with ethanol extraction. The overall phytochemical extraction efficiency is high in methanol solvent. This study found that the amount of phytochemical content in non-sunlight exposed freeze-dried oyster mushroom powder was higher than sunlight exposed oyster mushroom powder.

A Drop-in High-Temperature Pb-Free Solder Paste that Outperforms High-Pb Pastes in Power Discrete Applications

Sn-based high-temperature lead-free (HTLF) solder pastes have been developed as a drop-in solution to replace the high-Pb solder pastes in power discrete applications. The pastes were designed to combine the merits of two constituent powders. A SnSbCuAg powder, with the melting temperature above 320°C, was designed to maintain a high-temperature performance. A SnAgCuSb powder, with a melting temperature around 228°C, was added to the paste to enhance wetting and improve joint ductility. In the design, the final joint will have the low-melting phase (the melting temperature >228oC) in a controllable quantity embedded into the high-melting SnSbCuAg matrix. HTLF-1, one of the designs, maintained the bond shear strength up to 15MPa, even around 290°C. Another design, HTLF-2, has a similar bond shear strength as Pb92.5/Sn5/Ag2.5 around 290°C, but exceeds substantially below 250°C. The power discrete components had been built with both HTLF solder pastes for both die-attach and clip-bond through the traditional high-Pb process, which demonstrated the drop-in processing compatibility. The components survived three additional SMT reflows (peak temperature of 260°C) and passed moisture sensitivity level 1. This confirmed that the maintained joint strength (comparable to or stronger than high-lead), helped to keep the joint integrity within the encapsulated components, even with melting phases in a controllable quantity existing above 228°C. Both HTLF solder pastes outperformed Pb92.5/Sn5/Ag2.5 in RDS(on) even after 1000cycles of TCT (-55/175oC), which is attributed to the intrinsic lower electrical resistivity of Sn of both HTLF pastes. Microstructural observation had shown no corner cracks for both die-attach and clip-bond joints after TCT.

Machine learning framework for extracting micro-viscoelastic and micro-structural properties of compressed oral solid dosage forms

A compressed pharmaceutical oral solid dosage (OSD) form is a strongly micro-viscoelastic material composite arranged as a network of agglomerated particles due to its constituent powders and their bonding and fractural mechanical properties. An OSD product’s Critical Quality Attributes, such as disintegration, drug release (dissolution) profile, and structural strength (“hardness”), are influenced by its micro-scale properties. Ultrasonic evaluation is direct, non-destructive, rapid, and cost-effective. However, for practical process control applications, the simultaneous extraction of the micro-viscoelastic and scattering properties from a tablet’s ultrasonic response requires a unique solution to a challenging inverse mathematical wave propagation problem. While the spatial progression of a pulse traveling in a composite medium with known micro-scale properties is a straightforward computational task when its dispersion relation is known, extracting such properties from the experimentally acquired waveforms is often non-trivial. In this work, a novel Machine Learning (ML)-based micro-property extraction technique directly from waveforms, based on Multi-Output Regression models and Neural Networks, is introduced and demonstrated. Synthetic waveforms with a given set of micro-properties of virtual tablets are computationally generated to train, validate, and test the developed ML models for their effectiveness in the inverse problem of recovering specified micro-scale properties. The effectiveness of these ML models is then tested and demonstrated for a set of physical OSD tablets. The micro-viscoelastic and micro-structural properties of physical tablets with known properties have been extracted through experimentally acquired waveforms to exhibit their consistency with the generated ML-based attenuation results.

A Drop-in High-Temperature Pb-Free Solder Paste that Outperforms High-Pb Pastes in Power Discrete Applications

Sn-based high-temperature lead-free (HTLF) solder pastes have been developed as a drop-in solution to replace the high-Pb solder pastes in power discrete applications. The pastes were designed to combine the merits of two constituent powders. A SnSb-based Ag/Cu-containing high temperature powder, with the melting temperature above 320° C, was designed to maintain a high-temperature performance. A Sn-rich SnAgCu-Sb powder, with a melting temperature around 228° C, was added to the paste to enhance wetting and improve joint ductility. In the design, the final joint will have the low-melting phase (the melting temperature >228o C) in a controllable quantity embedded into the high-melting SnSb matrix. HTLF-1, one of the designs, maintained the bond shear strength up to 15MPa, even around 290° C. Another design, HTLF-2, has a similar bond shear strength as Pb92.5/Sn5/Ag2.5 around 290° C, but exceeds substantially below 250° C. The power discrete components had been built with both HTLF solder pastes for both die-attach and clip-bond through the traditional high-Pb process, which demonstrated the drop-in processing compatibility. The components survived three additional SMT reflows (peak temperature of 260° C) and passed moisture sensitivity level 1. This confirmed that the maintained joint strength (comparable to or stronger than high-lead), helped to keep the joint integrity within the encapsulated components in the following SMT process, even with the controlled quantity of the melting phases above 228° C. Both HTLF solder pastes outperformed Pb92.5/Sn5/Ag2.5 in the resistance from drain to source when power is on (RDS(on)), even after 1000cycles of TCT (-55/175o C), which is attributed to the intrinsic lower electrical resistivity of Sn of both HTLF pastes. Microstructural observation had shown no corner cracks for both die-attach and clip-bond joints after TCT.

New insight on rheology of self-consolidating earth concrete (SCEC)

Self-consolidating earth concrete (SCEC) is a novel alternative to facilitate the earth-based construction. A new concrete-equivalent mortar (CEM) approach with constant excess-paste (EP) thickness was proposed to evaluate the rheological and thixotropic properties of various SCEC mixtures proportioned with different clay and superplasticizer types. The use of non-esterified polycarboxylate (NE-PC) and sodium polynaphtalene superplasticizer types in combination with a finer clay type led to a thixotropic behavior. Mixtures made with sodium hexametaphosphate resulted in significantly high yield stress and plastic viscosity values. The rheological properties were mainly controlled by the admixture type, followed by the type and content of clay and water-to-powder ratio (W/P). Empirical models were proposed to predict the rheology of earth-based paste, CEM, and SCEC mixtures using the governing key mixture parameters, including the fineness of the powder constituents (i.e., clay, silt, and cement), water content, EP thickness, paste volume, and packing of the granular skeleton.

A Drop-In High-Temperature Pb-Free Solder Paste That Outperforms High-Pb Pastes in Power Discrete Applications

Sn-based high-temperature Pb-free (HTLF) solder pastes have been developed as a drop-in solution to replace high- Pb solder pastes in power discrete applications. The pastes were designed with Indium Corporation’s DurafuseVR technology, to combine the merits of two constituent powders. A SnSb-based Ag/ Cu-containing high-temperature powder, with a melting temperature above 320 degrees C, was designed to maintain high-temperature performance. A Sn-rich SnAgCu-Sb powder, with a melting temperature around 228 degrees C, was added to the paste to enhance wetting and improve joint ductility. In the design, the final joint will have the low-melting phase (the melting temperature >228 degrees C) in a controllable quantity embedded into the high-melting SnSb matrix. HTLF-1, one of the designs, maintained the bond shear strength up to 15 MPa, even around 290 degrees C. Another design, HTLF-2, has a similar bond shear strength as Pb92.5/Sn5/Ag2.5 around 290 degrees C, but exceeds substantially below 250 degrees C. The power discrete components had been built with both HTLF solder pastes for both die-attach and clip-bond through the traditional high-Pb process, which demonstrated the drop-in processing compatibility. The components survived three additional surface mounting (SMT) reflows (peak temperature upto 260 degrees C) and passed moisture sensitivity level 1 (MSL1). This confirmed that the maintained joint strength (comparable to or stronger than high-Pb), helped to keep the joint integrity within the encapsulated components in the following SMT process, even with the controlled quantity of the melting phases above 228 degrees C. Both HTLF solder pastes outperformed Pb92.5/Sn5/Ag2.5 in the resistance from drain to source when power is on (RDS(on)), even after 1,000 cycles of temperature cycling test (TCT) under 255/175 degrees C, which is attributed to the intrinsic lower electrical resistivity of Sn in both HTLF pastes. Microstructural observation had shown no corner cracks for both die-attach and clip-bond joints after TCT.

Characterisation of residual stresses and oxides in titanium, nickel, and aluminium alloy additive manufacturing powders via synchrotron X-ray diffraction

The strength and fracture toughness of Additively Manufactured (AM) components are significantly influenced by the concentration and size of oxides and precipitate inclusions within the build powders. These features are highly sensitive to powder production parameters, as well as the number of times a powder has been reused. In this study synchrotron X-ray powder diffraction was performed in an inert atmosphere at room temperature and during in-situ heating, providing crucial insights into growth rates and distribution of oxides and precipitates as a function of temperature. From the high angular resolution data collected, the structural refinement showed that plasma wire arc atomisation shows lower residual strain than gas atomised powder samples at room temperature after atomisation likely due to lower temperatures achieved during the production process. Additionally, the results from the diffraction patterns collected during in-situ heating provide key insights to the four metal powders considered in this study, Ti-6Al-4 V, Ni718, AlSi10Mg, and Scalmalloy. This paper also highlights the potential that using synchrotron X-ray diffraction to study AM parts and constituent AM powder has to gain crucial insight into material properties and the build reliability of end use production quality parts from AM.

Micro-viscoelastic Characterization of Compressed Oral Solid Dosage Forms with Ultrasonic Wave Dispersion Analysis.

Due to their constituent powders, the materials of advanced compressed oral solid dosage (OSD) forms are micro-composites and strongly visco-elastic at macro- and micro-length scales. The disintegration, drug release, and mechanical strength of OSD forms depend on its micro-texture (such as porosity) and micro-scale physical/mechanical properties. In the current work, an algorithmic ultrasonic characterization framework for extracting the micro-visco-elastic properties of OSD materials is presented, and its applicability is demonstrated with a model material. The proposed approach is based on the effect of visco-elasticity and granularity on the frequency-dependent attenuation of an ultrasonic wave pulse in a composite (granular) and viscous medium. In modeling the material, a two-parameter Zener model for visco-elasticity and a scattering attenuation mechanism based on Rayleigh scattering for long-wave approximation are employed. A novel linear technique for de-coupling the effects of micro-visco-elasticity and scattering on attenuation and dispersion is developed and demonstrated. The apparent Young's modulus, stress, and strain relaxation time constants of the medium at micro-scale are extracted and reported. Based on this modeling and analysis framework, a set of computational algorithms has been developed and demonstrated with experimental data, and its practical utility in pharmaceutical manufacturing and real-time release testing of tablets is discussed.

Organoleptic and Morphological Analysis of Citrus Peel Powder

Aim: Processing of citrus fruits results in the production of a >40 million tons of by-products worldwide and a major part of this by product is its peels. These peels have the potential of acting as a good nutraceutical resource owing to its high dietary fibre content and phenolic content. However, these peels are under-utilised despite their claimed health benefits. This study evaluates the morphological structure and sensory attributes of sweet lime peel and orange peel powder.
 Study Design: The present study was conducted in 3 phases-
 
 Collection of Raw Material
 Pretreatment & dehydration
 Processing into powder form.
 
 Place and Duration of the Study: The present study was conducted in the Department of Food &Nutrition of Babasa.heb Bhimrao Ambedkar University Lucknow. The duration of the study is 6 months i.e. from Jan, 2022- July, 2022.
 Methodology: Peels of sweet lime and orange were transformed into powder through solar drying followed by grinding. In the present study, we have compared the morphology and organoleptic constituents of orange peel powder (OPP) and sweet lime peel powder (SLPP). The morphology of the two samples was studied by Scanning Electron Microscopy (SEM) and element composition was studied and analysed by Energy Dispersive X-Ray Analysis (EDX). Organoleptic and sensory attributes were analyzed by a 9 pointer hedonic scale rating. Peel powders were also compared for two functional properties i.e. their Solubility Index and Swelling Power.

Development, and characterisation of ultra-high-temperature ceramics composite (UHTC)

ABSTRACT Ultra high-temperature ceramic (UHTC) composite materials are physically and chemically stable at high temperatures (more than 2000°C) and in reactive environments. Generally, the family group of diboride, dicarbide, and dinitride are used as ultra-high temperature ceramic due to their high thermal conductivity and high melting point. The main aim of this paper is the development of zirconium diboride (ZrB2)-based UHTC and characterisation of their density, hardness, porosity, and work considered, three powder constituents B4C (35%), ZrB2 (55%), and Cr (10%) of particle size 30 μm, 15 μm, and 4 μm, respectively, the conventional sintering and spark plasma sintering technique is used for the development of composite. The results revealed that the relative density of conventionally sintered composite at 1600°C and 1700°C are 72% and 80%, respectively, and spark plasma sintered composite at 1900°C is 99.99%. The bulk density and apparent porosity of SPS composite at 1900°C are 4.73 g/cm3 and 4%, respectively. Similarly, bulk density and apparent porosity of conventionally sintered composite, at 1600°C are 2.49 g/cm3 and 30%, respectively, and at 1700°C is 2.89 g/cm3 and 27%, respectively. Furthermore, the hardness of the SPS composite at 1900°C is 2830 HV, while the hardness of conventionally sintered composite at 1700°C and 1800°C were 280 HV and 520 HV, respectively. Additionally, scanning electron microscopy was performed to observe the bonding and porosity in the microstructure of the UHTC.

Preparation of MgF2–CaF2 nanocomposite ceramics with high infrared transmittance

Currently, most infrared nanocomposite ceramics are based on oxides. In this study, a brand-new system of infrared nanocomposite ceramics is proposed and realized. The new infrared nanocomposite ceramics contain two phases, MgF2 and CaF2, in a one-to-one volume ratio. The nanocomposite powders were synthesized by co-precipitation and calcination. The characterization of the as-prepared powders by X-ray diffraction and scanning electron microscopy revealed the presence of phases of ultrafine nanostructured MgF2 and CaF2, with an average particle size less than 30 nm. The nanocomposite ceramics were fabricated by hot-pressing the constituent powders at 650 ℃ under 200 MPa, yielding ceramics with a grain size less than 100 nm. The resulting nanocomposite ceramics exhibit excellent transmittance in the mid-IR region, which reaches 90 % in the wavelength range of 3–5 µm. These results demonstrate the promising application potential of fluoride infrared nanocomposite ceramics.

Powder preparation during ball milling and laser additive manufacturing of aluminum matrix nanocomposites: Powder properties, processability and mechanical property

• Nanocomposite powder for additive manufacturing was economically prepared. • The nanocomposite powder showed near-spherical shape and high flowability. • Nano-TiB 2 particles was uniformly dispersed on the surface of aluminum powder. • The optimal nanocomposite powder exhibited good processability. • The as-fabricated nanocomposite exhibited favorable mechanical property. The additive manufacturing method of laser powder bed fusion (LPBF) has a great potential in producing high-performance metal matrix nanocomposite components. However, nanocomposite powder feasible for LPBF is still limited in availability. In this work, AlSi10Mg powder containing 2 wt% TiB 2 nanoparticles was prepared by ball milling of the constituent powder to meet the following two criteria: (i) a uniform dispersion of nanoparticles on the surface of the micro powder and (ii) a high flowability of the produced nanocomposite powder. The evolution of the powder properties with the milling dose was studied. The results indicated that with the increase of milling dose, the nano-TiB 2 particles were dispersed uniformly but the Al matrix gradually underwent plastic deformation. Under optimized milling conditions, the aluminum matrix nanocomposite powder showed a small mean particle size, narrow size distribution, smooth surface, and a spherical shape with uniformly dispersed nanoparticles. These properties are beneficial for a good LPBF processability. During LPBF process, a favorable forming quality of the optimized nanocomposite powder was evident. A mechanical characterization demonstrated an outstanding tensile strength of ∼ 450 MPa and excellent ductility of ∼ 7.2 % for the built parts.

Organoleptic and Morphological Analysis of Citrus Peel Powder

Processing of citrus fruits results in production of a large amount of by product and a major part of this by product is its peels. These peels have the potential of acting as a good nutraceutical resource owing to its high dietary fibre content and phenolic content. However, these peels are under-utilised despite their claimed health benefits. This study evaluates the morphological structure, functional properties and sensory attributes of sweet lime peel and orange peel powder with a aim of providing an economical ingredient for the development of functional foods. Peels of sweet lime and orange were transformed into powder through solar drying followed by grinding. In the present study, we have compared the morphology and organoleptic constituents of orange peel powder (OPP) and sweet lime peel powder (SLPP). The morphology of the two samples was studied by SEM and element composition was studied and analysed by EDX. Organoleptic and sensory attributes were analyzed by a 9 pointer hedonic scale rating. Peel powders were also compared for two functional properties i.e. their Solubility Index and Swelling Power. Orange peel powder (OPP) had a better sensory rating than Sweet lime peel powder (SLPP). The morphology of both powders was same but SLPP had a slightly rough texture than OPP.

ANALYSIS OF THE BIOACTIVE AND MICROBIOLOGICAL CONTENTS OF HERBAL MIXTURES SOLD IN ANAMBRA STATE, NIGERIA

Over the years, medicinal plants have played a significant role in traditional medicine practice. The ever-increasing health-related difficulties and the search for possible treatments and likely cures have led to the increasing patronage of herbal drugs in Nigeria. There is an overwhelming increase in the production and distribution of herbal medications, and the trend has instigated concern about the quality of the products being sold in Anambra State, Nigeria. Thus, the primary purpose of the current study is to analyze the microbiological and phytochemical constituents of okanga powder, goko cleanser, and deep root herbal mixtures popularly sold in Nigeria. The phytochemical tests conducted on the herbal products revealed that the herbal products contain alkaloids, flavonoids, glycosides, anthraquinones, tannins, and saponins. The result of the microbial count indicates the presence of varying microorganisms such as S. aureus, E. coli, Salmonella, and Klebsiella spp in the herbal products. The study concludes that herbal products possess active phytochemicals. However, the presence of pathogenic organisms was discovered in the herbal drugs.

Estimating deposition efficiency and chemical composition variation along thickness for cold spraying of composite feedstocks

The low working temperature of cold spray technology offers a unique possibility to deposit a wide variety of composite materials by mixing two or more constituent powders. However, while it is possible to precisely control the chemical composition of the mixture before spraying, the compositional yield in the deposit remains uncertain. This is mainly due the variation of deposition kinetics between the constituent phases leading to a compositional deviation with respect to the feedstock. The mismatch in thermo-mechanical properties of the materials included in the feedstock can also lead to the variation of deposit composition along its thickness. Here, we paired a probabilistic approach with finite element simulations to estimate the deposition efficiency of the mixed powder and assess the actual composition of the cold spray multi-material deposit. The developed model accounts for the interaction of the powders with the substrate and estimates the deposition probability based on the actual deformation of particles of each individual phase during deposition. The model is validated by comparison with experimental data in the case of zinc‑aluminum mixture, that is known as a promising option for corrosion-resistant coatings thanks to its excellent cathodic protection. The results confirm the adeptness of the proposed model in predicting the deposition efficiency as well as deposit composition variation along the thickness with a high accuracy in the case of multi-material deposits.

Studies on changes in chemical constituents of raw mango powder (Amchur) during storage

Study was done on changes taking place in chemical constituents of raw mango powder (Amchur) during storage in the post-harvest technology laboratory of the horticulture section of Dr Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli, Maharashtra. The biochemical analysis of nutritional values viz acidity, ascorbic acid, starch and beta-carotene were carried out and were found to be decreased during a period of 9 months and the moisture, total soluble solids, reducing sugar and total sugar were found to be increased.