Production and stability of al and cu ultrafine particles in nanofluids

In this paper, a two step approach of synthesis of Al and Cu ultrafine particles by mechanical alloying and then dispersing them in base fluid to prepare nanofluid has been reported. Ultrafine powders were prepared by milling elemental Al and Cu powders for 50 h in a planetary mill. After 50 h of milling, particles size has been reduced to 500nm for Al and 400 nm for Cu. It is also found from transmission electron microscopy (TEM) that each particles consists of large number of crystallites of size around 10-15 nm. Aiming at the dispersion of nano-Al and Cu is regarded as the guide of heat transfer enhancement, the stability of Al and Cu particles in water were studied under different pH values. It has been found from Nanozeta meter that Al suspension is stable at pH 2.5 and 9.5, whereas Cu suspension is stable at pH 2.3 and 9.8

Synthesis and characterization of nanocrystalline carbides By reaction milling

Nanocrystalline cementite, silicon carbide and titanium carbide powders were prepared from elemental constituent powder particles by reaction milling. A high energy dual drive planetary mill has been fabricated for the synthesis of carbides. The strong collision energy field of the dual drive planetary mill reduced the carbide formation time as compared to earlier reported studies. Forty hours is required to produce nanocrystalline cementite and silicon carbide powder. Whereas only 10 hours is required to produce titanium carbide powder, because self propagating reaction takes place between Ti and graphite during milling. The morphology of powders and evolution of different phases were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM)

Chemical characterisation and the anti-inflammatory, anti-angiogenic and antibacterial properties of date fruit (Phoenix dactylifera L.)

Ethnopharmacological relevance: Date fruit, Phoenix dactylifera L. has traditionally been used as a medicine in many cultures for the treatment of a range of ailments such as stomach and intestinal disorders, fever, oedema, bronchitis and wound healing. Aim of the review: The present review aims to summarise the traditional use and application of Phoenix dactylifera date fruit in different ethnomedical systems, additionally the botany and phytochemistry are identified. Critical evaluation of in vitro and in vitro studies examining date fruit in relation to anti-inflammatory, anti-angiogenic and antimicrobial activities are outlined. Key Findings: The ethnomedical use of Phoenix dactylifera in the treatment of inflammatory disease has been previously identified and reported. Furthermore, date fruit and date fruit co-products such as date syrup are rich sources of polyphenols, anthocyanins, sterols and carotenoids. In vitro studies have demonstrated that date fruit exhibits antibacterial, anti-inflammatory and anti-angiogenic activity. The recent interest in the identification of the numerous health benefits of dates using in vitro and in vivo studies have confirmed that date fruit and date syrup have beneficial health effects that can be attributed to the presence of natural bioactive compounds. Conclusions: Date fruit and date syrup have therapeutic properties, which have the potential to be beneficial to health. However, more investigations are needed to quantify and validate these effects

Synthesis of nano-structured duplex and ferritic stainless steel powders by dry milling and its comparison with wet milling

In the present paper, elemental Fe, Cr and Ni powders were used to fabricate nano-structured duplex and ferritic stainless steel powders by using high energy planetary ball milling. We have studied the effect of milling atmosphere like wet (toluene) and dry (argon) milling of elemental Fe-18Cr-13Ni (duplex) and Fe-17Cr-1Ni (ferritic) powders for 10 h in a dual drive planetary mill. Stearic acid of 1wt.% was added during milling to avoid agglomeration. The dry and wet milled duplex and ferritic stainless steel powders were characterized by XRD, SEM and particle size analysis techniques. We have found that both the milling atmospheres have great influence in controlling the final particle morphology, size and phase evolution during milling. It was reported that dry milling is more effective in reducing particle size than the wet milling. The Nelson-Riley method of extrapolation was used to calculate the precise lattice parameter and Williamson-Hall method was used to calculate the crystallite size and lattice strain of both the stainless steel milled in argon atmosphere. Dry milled duplex and ferritic stainless steel were then consolidated by conventional sintering method at 1100, 1200 and 1300°C temperatures under argon atmosphere for 1 hour

The Analysis of Syntactical Interference in English Phrases in Students\u27 Writing (a Descriptive Study at the Second Grade Students of SMP 2 Kuta Baro, Aceh Besar)

This qualitative-descriptive research attempts to describe Indonesian interference in building English phrases in writing. The research was undertaken to the second year students of SMP 2 Kuta Baro, Aceh Besar. This study aims to verify the Indonesian interference made by students in English phrases. The data were collected through document analysis which then the sample was selected to be analyzed. The sample of this study was twelve narrative texts composed by the students. The finding of data analysis reveals that there are some syntactical interference samples made by them as in scenery roads, voice strange, morning Sunday, water bath, garden flower, and advice future. These are resulted from Indonesian interference because they applied Indonesian structure in building English phrases. In conclusion, the research result shows that the students have lack of grammar knowledge in constructing English phrases. Therefore, they borrow Indonesian structure as a solution for their difficulties. For this reason, the teaching should focus more on how to build English phrases correctly by giving many samples of nounʸ + nounˣ (where nounˣ means head and nounʸ means modifier) pattern all well as explaining the rule in English as the target language they are learning. It hopes that they will not transfer the Indonesian pattern when they are writing in English

Synthesis of nano-structured duplex and ferritic stainless steel powders by dry milling and its comparison with wet milling

In the present paper, elemental Fe, Cr and Ni powders were used to fabricate nano-structured duplex and ferritic stainless steel powders by using high energy planetary ball milling. We have studied the effect of milling atmosphere like wet (toluene) and dry (argon) milling of elemental Fe-18Cr-13Ni (duplex) and Fe-17Cr-1Ni (ferritic) powders for 10 h in a dual drive planetary mill. Stearic acid of 1wt. % was added during milling to avoid agglomeration. The dry and wet milled duplex and ferritic stainless steel powders were characterized by XRD, SEM and particle size analysis techniques. We have found that both the milling atmospheres have great influence in controlling the final particle morphology, size and phase evolution during milling. It was reported that dry milling is more effective in reducing particle size than the wet milling. The Nelson-Riley method of extrapolation was used to calculate the precise lattice parameter and Williamson-Hall method was used to calculate the crystallite size and lattice strain of both the stainless steel milled in argon atmosphere. Dry milled duplex and ferritic stainless steel were then consolidated by conventional sintering method at 1100, 1200 and 1300°C temperatures under argon atmosphere for 1 hour. © 2020. The Author(s)

Effect of Y2O3 Nanoparticles on Corrosion Study of Spark Plasma Sintered Duplex and Ferritic Stainless Steel Samples by Linear Sweep Voltammetric Method

The microstructure and corrosion properties of spark plasma sintered yttria dispersed and yttria free duplex and ferritic stainless samples were studied. Spark plasma sintering (SPS) was carried out at 1000°C by applying 50 MPa pressure with holding time of 5 minutes. Linear sweep voltammetry (LSV) tests were employed to evaluate pitting corrosion resistance of the samples. Corrosion studies were carried out in 0.5, 1 and 2 M concentration of NaCl and H2SO4solutions at different quiet time of 2, 4, 6, 8 and 10 seconds. Yttria dispersed stainless steel samples show more resistance to corrosion than yttria free stainless steel samples. Pitting potential decreases with increase in reaction time from 2 to 10 seconds. Similarly, as concentration of NaCl and H2SO4 increases from 0.5 M to 2 M the corrosion resistance decrements due to the availability of more Cl¯ and SO42¯ ions at higher concentration

Towards Reliable 10 mu m Pitch Assembly Using Cu/Ni/SnAg based Interconnects

19th IEEE Electronics Packaging Technology Conference (EPTC), Singapore, SINGAPORE, DEC 06-09, 2017International audienceIn this paper, the interconnect for 10 mu m are evaluated. Two processes for obtaining interconnects for 10 mu m pitch are compared in terms of reliability. One process yields the interconnects with Ni3Sn4 intermetallic (IMC) joint (interconnect A) while other yields the interconnects with solder joint (interconnect B). To select the best process for the assembly at 10gim pitch, high temperature storage tests are performed at 150 degrees C, 175 degrees C and 200 degrees C for 500hrs. The evolution of the metallurgy for both the interconnects is evaluated. The failure mechanism is determined by measuring the change in resistance. On the basis of mechanism, failure statistic is made. Finally, the obtained results are discussed