Salt Powder Research Articles

Electrochemical synthesis and characterization of polyaniline thin film and polyaniline powder

The polyaniline thin film electrode and powder have been synthesized on graphite electrodes from 0.5 M hydrochloric acid solution under galvanostatic conditions. The water insoluble and acetone soluble polyaniline mass fractions of the powder, as well as the polymerization efficiency, based on the emeraldine salt have been determined. The morphology of the obtained emeraldine salt powder has been investigated by the optical microscopy.

Low Temperature Production of Lead-Free Piezoelectric Thick Films

Lead-free piezoelectric materials have grown in importance through increased environmental concern and subsequent EU legislation. Integration of the next generation lead-free piezoelectric materials with substrates to form functional micro devices has received less attention. A low temperature molten salt powder synthesis combined with a hybrid powder/sol gel ink film have been used to produce lead free NaNbO3/Ka0.5Na0.5NbO3 thick films on substrates. The films have exhibited ferroelectric behaviour with piezoelectric coefficients in the region of 18pC/N.

Effect of catalyst calcination temperature on the synthesis of MWCNT–alumina hybrid compound using methane decomposition method

This work focuses on synthesis of MWCNT–alumina hybrid compound via methane decomposition process using Ni–Al 2O 3 catalyst. The catalysts prepared through in situ process by using nickel salt and aluminium powder which are then calcined at three different calcination temperatures (700 °C, 900 °C and 1100 °C). The catalyst calcined at 900 °C followed by methane decomposition process successfully yielded MWCNT–alumina hybrid compound. No trace of CNT was detected for catalyst calcined at 700 °C and 1100 °C. The scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) micrograph confirmed the formation of MWCNT with homogenous dispersion on alumina particles.

Radar for detection of ultra-high-energy neutrinos reacting in a rock salt dome

Detection of GZK (Greisen, Zatsepin and Kuzmin) neutrinos that have an energy larger than 1×10 16 eV are expected to explore ultra-high-energy (UHE) interactions between UHE protons (>4×10 19 eV) and cosmic-microwave background in the cosmological distances. A study of the radar method was carried out using a 2 MeV electron beam to irradiate rock salt powder filled in a 435 MHz waveguide. Reflection of radio wave from the irradiated rock-salt powder was observed inside the waveguide. The reflection mechanism was elucidated and the reflection power ratio was compared with a Fresnel equation.

Bulk gold with hierarchical macro-, micro- and nano-porosity

Millimeter-sized, free-standing gold structures were created with three levels of multiscale porosity. First, macro- and microporosity, which are useful for mass and heat transport within the structure, are formed within an Ag–19at.% Au alloy by salt powder replication during powder densification and by entrapped gas expansion during sintering, respectively. Nanoporosity, which provides high surface area, is then produced by silver dealloying of these Ag–19at.% Au foams. The resulting hierarchical gold structures are annealed at 100–800°C, thus coarsening the ligaments, increasing relative density, and healing cracks produced during dealloying. The first effect weakens the structure, while the other two make it stronger. A bulk Au sample with hierarchical porosity annealed at 600°C shows good compressive ductility and a strength in agreement with models.

Molluscicidal efficacies of different formulations of niclosamide: result of meta-analysis of Chinese literature

The control efforts on Oncomelania hupensis, the intermediate snail host of Schistosoma japonicum, cannot be easily excluded from the integrated approach of schistosomiasis control in China. Application of chemical compounds, molluscicides, in snail habitats is a common method for snail control in addition to environmental modification. We conducted a systematic review and meta-analysis to assess the molluscicidal effects of the currently recommended 50% niclosamide ethanolamine salt wettable powder and a new 4% niclosamide ethanolamine salt powder developed by Chinese researchers. Literature was searched from three Chinese databases, i.e. Chinese Biomedical Database, VIP Database and Wanfang Database, on field mollusciciding trials of niclosamide in China (from January 1, 1990 to April 1, 2010). Molluscicidal effects on reduction of snail population of the 50% or 4% niclosamide formulations in field trial were evaluated 3 days, 7 days or 15 days post-application. Out of 90 publications, 20 papers were eventually selected for analysis. Publication bias and heterogeneity tests indicated that no publication bias existed but heterogeneity between studies was present. Meta-analysis in a random effect model showed that the snail mortality of 3, 7 and 15 days after spraying the 50% niclosamide ethanolamine salt wettable powder were 77% [95%CI: 0.68-0.86], 83% [95%CI: 0.77-0.89], and 88% [95%CI: 0.82-0.92], respectively. For the 4% niclosamide ethanolamine salt powder, the snail mortality after 3, 7 and 15 days were 81% [95%CI: 0.65-0.93], 90% [95%CI: 0.83-0.95] and 94% [95%CI: 0.91-0.97], respectively. Both are good enough to be used as molluscicides integrated with a schistosomiasis control programme. The 4% niclosamide ethanolamine salt powder can be applied in the field without water supply as the surrogate of the current widely used 50% niclosamide ethanolamine salt wettable powder. However, to consolidate the schistosomiasis control achievement gained, it is necessary to continuously perform mollusciciding more than twice annually in the field.

Studying an effect of salt powder seeding used for precipitation enhancement from convective clouds

Abstract. Experimental and theoretical studies of cloud microstructure modification with hygroscopic particles for obtaining additional precipitation amounts from convective clouds are performed. The experiment used salt powder with the particle sizes that gave the greatest effectiveness according to the simulations of Segal et al. (2004). The experiments were carried out in a cloud chamber at the conditions corresponding to the formation of convective clouds. The results have shown that the introduction of the salt powder before a cloud medium is formed in the chamber results in the formation on a "tail" of additional large drops. In this case seeding with the salt powder leads also to enlargement of the whole population of cloud drops and to a decrease of their total concentration as compared to a cloud medium that is formed on background aerosols. These results are the positive factors for stimulating coagulation processes in clouds and for subsequent formation of precipitation in them. An overseeding effect, which is characterized by increased droplet concentration and decreased droplet size, was not observed even at high salt powder concentrations. The results of numerical simulations have shown that the transformation of cloud drop spectra induced by the introduction of the salt powder results in more intense coagulation processes in clouds as compared to the case of cloud modification with hygroscopic particles with relatively narrow particle size distributions, and for the distribution of the South African hygroscopic flares. The calculation results obtained with a one-dimensional model of a warm convective cloud demonstrated that the effect of salt powder on clouds (total amounts of additional precipitation) is significantly higher than the effect caused by the use of hygroscopic particles with narrow particle size distributions at comparable consumptions of seeding agents, or with respect to the hygroscopic flares. Here we show that seeding at rather low consumption rate of the salt powder initiates precipitation from otherwise non precipitating warm convective clouds, mainly by the effect of adding large cloud drops to the tail of the distribution.

A Quest for Effective Hygroscopic Cloud Seeding

Abstract It is shown here that hygroscopic seeding requires two orders of magnitude more hygroscopic agent than can be delivered by flare technology for producing raindrop embryos in concentrations to detect by cloud physics aircraft the microphysical signature of rain initiation. An alternative method of finely milled salt powder is shown to be capable of achieving this goal. During field experiments the use of a sulfur hexafluoride (SF6) gas tracer to identify the exact seeded cloud volume and to quantify dilution of the seeding agent showed that the seeding agent dilutes to the order of 10−10 of its released concentration in updrafts at a height of ≥1 km above cloud base. This means that the theoretically expected changes in the cloud drop size distribution (DSD) would not be detectable with a cloud droplet spectrometer in a measurement volume collected during the several seconds that the seeded volume is traversed by an aircraft. The actual measurements failed to identify a clear microphysical seeding signature from the burning of hygroscopic flares within the seeded convective clouds. This uncertainty with respect to hygroscopic flare–seeding experiments prompted an experimental and theoretical search for optimal hygroscopic seeding materials. This search culminated in the production of a salt powder having 2–5-μm-diameter particle sizes that are optimal according to model simulations, and can be distributed from a crop duster aircraft. Such particles act as giant cloud condensation nuclei (GCCN). Any potential broadening of the DSD at cloud base by the competition effect (i.e., when the seeded aerosols compete with the natural ambient aerosols for water vapor) occurs when the seeding agent has not been substantially diluted, and hence affects only a very small cloud volume that dilutes quickly. Therefore, the main expected effect of the GCCN is probably to serve as raindrop embryos. The salt powder–seeding method is more productive by two orders of magnitude than the hygroscopic flares in producing GCCN that can initiate rain in clouds with naturally suppressed warm rain processes, because of a combination of change in the particle size distribution and the greater seeding rate that is practical with the powder. Experimental seeding of salt powder in conjunction with the simultaneous release of an SF6 gas tracer produced strong seeding signatures, indicating that the methodology works as hypothesized. The efficacy of the accelerated warm rain processes in altering rainfall amounts may vary under different conditions, and requires additional research that involves both observations and simulations.

KNO3/NaNO3 – Graphite materials for thermal energy storage at high temperature: Part II. – Phase transition properties

Abstract Composites graphite/salt for thermal energy storage at high temperature (∼200 °C) have been developed and tested. As at low temperature in the past, graphite has been used to enhance the thermal conductivity of the eutectic system KNO 3 /NaNO 3 . A new elaboration method has been proposed as an alternative to graphite-foams infiltration. It consists of compression at room temperature of a physical mixing of expanded natural graphite particles and salt powder. Two different compression routes have been investigated: uni-axial compression and isostatic compression. The first part of the paper shows that both uni-axial and isostatic cold-compression are simple and equally efficient techniques for improving the salt thermal conductivity. The second part of the paper is focused on the analysis of their phase transition properties. It is shown that graphite does not degrade the salt within the composites; that is, no changes are observed neither in the salts transition temperatures nor in its latent heat. On the contrary, some negative effects as pores over pressurization and salt leakage can appear if no void space enough is available within the composite for salt volume expansion when melting. Such negative effects are only observed in the composites obtained by isostatic cold-compression.

KNO3/NaNO3 – Graphite materials for thermal energy storage at high temperature: Part I. – Elaboration methods and thermal properties

Abstract Composites graphite/salt for thermal energy storage at high temperature (∼200 °C) have been developed and tested. As at low temperature in the past, graphite has been used to enhance the thermal conductivity of the eutectic system KNO 3 /NaNO 3 . A new elaboration method has been proposed as an alternative to graphite foams infiltration. It consists of cold-compression of a physical mixing of expanded natural graphite particles and salt powder. Two different compression routes have been investigated: uni-axial compression and isostatic compression. The first part of the paper has been devoted to the analysis of the thermal properties of these new graphite/salt composites. It is proven that cold-compression is a simple and efficient technique for improving the salt thermal conductivity. For instance, graphite amounts between 15 and 20%wt lead to apparent thermal conductivities close to 20 W/m/K (20 times greater than the thermal conductivity of the salt). Furthermore, some advantages in terms of cost and safety are expected because materials elaboration is carried out at room temperature. The second part of the paper is focused on the analyses of the phase transition properties of these graphite/salt composites materials.

Effect of Ball Milling on Microstructure and Flexural Strength of Ti(C,N)-Ni Cermets

Ti(C,N) cermets were prepared by SPS method. The effects of nickel salt coating as well as ball milling times on the microstructure and mechanical properties of the cermets were investigated. SEM images shows that the nickel was coated homogeneously on the surface of Ti(C,N) powders by mixing Ni salt and Ti(C,N) powder. The grains of Ti(C,N)-based cermets became finer with increasing ball milling time. The flexural strength increased when the balling milling was below 48h, and then decreased with increasing of ball milling time, which was due to the decrease of the flake structure in cermets.

Low-cost phantoms for training of stereotactic vacuum-assisted biopsy of the breast

To test low-cost phantoms for training in stereotactic breast biopsy, we prepared eggplant with calcium powder; gelatin and turkey breast with coarse salt, peppercorns, and calcium powder, respectively; and short-bread pastry with salt. Three to 12 cores were harvested with an 11-gauge vacuum biopsy unit. Mammography images were taken before and after biopsy and from the biopsy cores. The pastry phantom provided the best simulation of microcalcifications for stereotactic biopsy with realistic cores, long durability, and short preparation time.

Quality Assessment of Vacuum Packaged Chicken Snacks Stored at Room Temperature

Chicken snacks were prepared by utilizing spent hen meat, sodium caseinate and rice flour, spice mix, condiments, common salt, phosphate and baking powder. The control was prepared in a similar manner except that, spent hen meat was substituted by equal quantity of rice flour. Chicken snack and control were packaged under vacuum in laminated (polyethylene/aluminium foil) pouches (size 25 × 20 cm), stored at 30 ± 2°C. The changes in physico-chemical characteristics, sensory attributes and microbiological profile of vacuum packaged chicken snacks, as well as control were analyzed during storage at room temperature (30 ± 2°C) for 30 days with regular intervals of six days. Both chicken snacks and control indicated non-significant effect of treatment on days of storage with respect to the contents of fat, protein, ash, pH, total plate count (TPC), yeast and mould counts (YMC). However, shear force value in treated products were significantly (P<0.05) different on day 0 and 6 from the rest of the storage days. The TBA values for control on day 0, 6, 12 were found significantly different from the rest of the storage days. Sensory attributes for both control and treated products were found to be less affected by the days of storage in the whole of the storage period. Overall comparison of physico-chemical, microbiological and sensory profiles of control and treated products found highly significant (P<0.01) difference except for some values of moisture, shear force and pH. The study revealed that both products can be stored under vacuum in very good condition up to 30 days at room temperature. Key words: Chicken snack, spent hen meat, rice flour, sodium caseinate, vacuum.

Effect of salt, kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat during refrigerated storage

Effects of salt, kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat stored at 4+/-1 degrees C was evaluated. Five treatments evaluated include: control (only meat), MS (meat+2% salt), KRP (meat+2% salt+2% kinnow rind powder), PRP (meat+2% salt+2% pomegranate rind powder) and PSP (meat+2% salt+2% pomegranate seed powder). Addition of salt resulted in reduction of redness scores. Lightness increased in control and unchanged in others during storage. Redness scores declined and yellowness showed inconsistent changes during storage. Thiobarbituric acid reactive substances (TBARS) values were higher (P<0.05) in MS followed by control and KRP samples compared to PRP and PSP samples throughout storage. The PSP treated samples showed lowest TBARS values than others. Percent reduction of TBARS values was highest in PSP (443%) followed by PRP (227%) and KRP (123%). Salt accelerated the TBARS formation and by-products of kinnow and pomegranate fruits counteracted this effect. The overall antioxidant effect was in the order of PSP>PRP>KRP>control>MS. Therefore, these powders have potential to be used as natural antioxidants to minimize the auto-oxidation and salt induced lipid oxidation in raw ground goat meat.

Effect of different mixing ways in palladium/ceria-zirconia/alumina preparation on partial oxidation of methane

The effect of the mixing ways of Ce 0.7Zr 0.3O 2-Al 2O 3 mixed oxides on the partial oxidations of methane (POM) was investigated over Pd/Ce 0.7Zr 0.3O 2-Al 2O 3 catalysts, the mixing ways including salt precursor mixing (ATOM), precipitator mixing (MOL), and powder mechanically mixing (MECH), respectively. The test results indicated that among the three samples, Pd/ATOM had the best catalytic activity, while Pd/MOL had the best stability in the stability test. Both the activity sequences of the fresh and used samples were consistent with the order of Pd dispersion. According to the X-ray diffraction (XRD) and BET characterization, the interaction of Ce 4+, Zr 4+, and Al 3+ in the ATOM mixed oxide was in favor of performing higher catalytic activity and thermal stability. The stability test indicated that Pd/MOL had the highest Pd dispersion and least coke formation on the active sites calculated by the H 2-chemisorption and TG results, which was considered to relate to its superior activity of POM to other catalysts.

Grain refinement response of LM25 alloy towards Al–Ti–C and Al–Ti–B grain refiners

The grain refining response of LM25 (Al–7Si–0.35Mg) alloy has been studied with the newly made Al–5Ti–0.8C and Al–5Ti–1.2C master alloys which have been successfully prepared in the laboratory by reaction of K 2TiF 6 salt and graphite powder with Al. The results have been compared with the grain refining efficiency of Al–3B, Al–1Ti–3B and Al–5Ti–1B master alloys on LM25 alloy at different addition levels. The results show that the grain refining efficiency of even lowest addition level (0.1 wt.%) of both Al–5Ti–0.8C and Al–5Ti–1.2C master alloys are equivalent to the 1.0 wt.% addition levels of Al–1Ti–3B and better than 1.0 wt.% of Al–3B master alloy. At higher addition levels of Al–5Ti–0.8C and Al–5Ti–1.2C master alloys exhibits fading in grain structure on longer holding due to agglomeration of TiC particles and poisoning of Si.

Deterioration of dolostone by magnesium sulphate salt: An example of incompatible building materials at Bonaval Monastery, Spain

Since its abandonment 185 years ago, the XII century Santa Maria de Bonaval Monastery located in Guadalajara (Spain) has suffered significant deterioration: first the roof was lost, followed by partial collapse of the walls, moisture infiltration and extensive loss of stone surfaces due to salt weathering. This case study is a clear example of the incompatibility of some building materials: in this case, the combination of sulphate-bearing mortars and magnesium-rich stone and mortars leading to extensive weathering by magnesium sulphate crystallization. Samples of plaster, bedding and core mortars, stone fragments and flakes, salt crust and powders were collected, as well stone samples from the historic quarries located close to the Monastery. Characterization by XRD (X-ray diffraction), ESEM-EDS (environmental scanning electron microscopy with energy dispersive X-ray spectroscopy) shows that the most important stone-type used in the structure, dolostone, is mainly affected by magnesium sulphate salts (epsomite, MgSO 4 · 7H 2O), although other salts as kalicinite (KHCO 3) and mercallite (KHSO 4) were also detected. The connected porosity and pore size distribution determined by mercury intrusion porosimetry and capillarity behaviour suggest that the core mortar could easily be dissolved and the stone, plaster and bedding mortars are able to transport infiltrating solutions, giving rise to the precipitation of magnesium sulphate in the mortar joints and over the surface of the stone. Due to their chemical incompatibility, the combination of sulphate and magnesium-bearing mortars and stone with high magnesium content appears to be problematic and should be avoided in future restoration work.

A novel molluscicidal formulation of niclosamide

Snail control by molluscicides is an important strategy for schistosomiasis control in China. Currently, only one chemical molluscicide, niclosamide, which is used as 50% wettable powder of niclosamide ethanolamine salt (WPN), is commercially available for field snail control in China. However, WPN is costly, toxic, and has a lower dispersibility and precipitates rapidly. In this paper, we describe the development of a novel formulation of niclosamide, a suspension concentrate of niclosamide (SCN). The efficacy of SCN was evaluated both in the laboratory and field. SCN showed better molluscicidal effects than conventional formulation of WPN, as determined by LC(50) for adult snails, young snails, and snail eggs. The acute toxicity of SCN to Brachdanio rerio hamiton was less than WPN. In conclusion, the novel formulation of SCN suspension is physically more stable, more effective, and less toxic. Therefore, it can be more useful for controlling snails in endemic areas of schistosomiasis in China.

Preservation of Cauda Epididymis in Powder of Salt or Sugar at Room Temperature.

The generally accepted method for sperm preservation is by freezing in liquid nitrogen at -196 EC. However, this requires a constant replacement of liquid nitrogen for long-term preservation. Development of preservation techniques for male gametes at room temperature would allow us to store them with a simple and cost-effective manner. It has been known that food can be preserved in salt for long periods at room temperature. Therefore, in this study, we have tried to develop a new sperm preservation method at room temperature using a powder of salt and sugars. Whole cauda epididymides of mature B6D2F1 mouse were placed directly in a powder of pure salt (NaCl), sugars (glucose, raffinose or trehalose) or without any additives (untreated control) for 1 day to 1 month, at room temperature. Epididymides were then rehydrated with Hepes-CZB or NIM medium for 15 min at 4EC, and the sperm were collected by disrupting the epididymis using tweezers. In some experiments, cauda epididymides were gradually dehydrated using different concentrations of sugars in water, to avoid the rapid water replacement damage, and rehydration time was extended to avoid insufficient rehydration. The quality of stored spermatozoa was evaluated by their oocyte activation capacity and developmental potential after intracytoplasmic sperm injection (ICSI). When the cauda epididymis was stored for 1 week, there were no significant differences in the oocyte activation capacity of spermatozoa when compared to the fresh control, irrespective of storage conditions (stored: n= 533, fresh: n= 328; 88 to 100% vs 98%). However, when the cauda epididymis was stored for 1 month, the rate of activated oocytes decreased significantly in the untreated control (n= 130; 5%), whereas the cauda epididymis stored in salt or sugar showed that most spermatozoa still retained oocyte activation capacity after ICSI (n= 251; 83 to 95%). Activated oocytes formed male and female pronuclei which appeared normal and extrudes a second polar body 6 h after ICSI. We also examined pronuclear morphology and methylation status of histone H3 lysine 9 (H3K9) in zygotes by immunofluorescence staining, but we did not observe any differences between zygotes fertilized with stored and fresh spermatozoa (stored: n= 71, fresh: n= 30). However, the developmental ability of zygotes generated by ICSI using stored sperm showed a significant decrease. When epididymides were stored in glucose or raffinose for 1 day at room temperature, only 2% and 17% of embryos developed to blastocyst (glucose: n= 203, raffinose: n= 132), and after transfer into recipient females, only 1% and 7 % of them developed to full term (glucose: n= 208, raffinose: n= 182), respectively. However, when epididymides were stored for 1 month in glucose or raffinose, or stored in salt or trehalose for 1 day, none of embryos developed to the blastocyst stage. This could not be improved even when the epididymis was dehydrated gradually (n= 162) and rehydration time was extended (n= 259). We examined the cause of developmental arrest in embryos injected with sperm stored for 1 day and found that 100% (NaCl) or 87.8% (glucose) embryos showed aberrant chromosome segregation at the 2-cell stage (fresh: 7%). In conclusion, although the activation factor(s) is maintained in sperm preserved with salt or sugar for at least 1 month at room temperature, their developmental capacity were lost due to the abnormal distribution of the chromosomes.

Cryocrystallization during preparation of ferrites by cryochemical technology

Characteristics are considered for material prepared by cryochemical technology connected with its thermal conductivity and heat capacity, i.e., heat penetration coefficient. It is concluded that for rapidly occurring solidification it is desirable to use in calculations not the temperature of the cooling medium or substrate, but the contact temperature of interacting media, and this increases calculation accuracy. The effect of cooling rate with evaporation freezing of aqueous salt solutions of nickel, zinc, manganese and iron sulfate systems that are the starting material in the production of Ni-Zn and Mn-Zn ferrites, and also the properties of the salt and oxide powders obtained are studied. It is shown that under these conditions an effect arises of concentration supercooling of liquid, i.e., formation close to the phase transformation front of a region of supersaturated and supercooled solution that gives rise to loss of stability for the phase interface. The effect of cooling rate and frequency on material fineness and microstructure is analyzed. Features are demonstrated of solidification in a vacuum compared with other freezing methods.