422 research outputs found
Health Monitoring of Induction Motor Through Vibration Analysis
Machinery monitoring is the process of monitoring a parameter of condition in machinery, such that a significant change is indicative of a failure in development. Temperature, vibration, noise, current, voltage, acoustic emission, etc. – all these measurements are used for machine condition monitoring. Measuring vibration signals of the Non-Destructive Testing (NDT) method is widely used to detect machine faults. There are many studies for the prediction of mechanical wear, fault and failure in this area for several decades. Signal processing techniques are used to obtain vital characteristic information from the vibration signals. This paper attempts to summarize the results of an evaluation of vibration analysis techniques as a method for diagnosis for three-phase induction motors
XRD and FT-IR investigations of sub-bituminous Assam coals
Two coal samples collected from Makum coal field,
Assam, India were studied by XRD and FT-IR techniques.
The X-ray diffractogram shows the existence of some
crystalline carbons in Assam coals as proven by the
appearance of peaks. The radial distribution functional
(RDF) method was applied for the determination of
structural aspects of the coals. The study indicates that
the coals are lignite in type and there is no evidence of
graphite-like structures. The maximum in the G(r) plots
of function of radial distribution of atoms (FRDA) relates
to different distances between carbon atoms of aliphatic
chains. The first significant maximum relates to the C-C
bond (type C-CH=CH-C), the second maximum relates
to the distance between carbon atoms of aliphatic chains
that are located across one carbon atom. The curve
intensity profiles obtained from FRDA show quite regular
molecular packets for this coal. The coals were found to
be lignite in nature. FT-IR study shows the presence of
aliphatic carbon, C=O and C-O stretching associated with
-OH and -NH stretching vibrations. Kaolinite and quartz
were also found to be major minerals in Assam coals by
FTIR spectroscopy. The difference in intensities of
carbonyl groups of the coal samples is likely to relate
with the rank. © Indian Academy of Sciences
Twórczość plastyczna jako forma wspierania rozwoju osób niewidomych i głuchoniewidomych
Twórczość plastyczna wydaje się być niedocenianym przez tyflopedagogów obszarem aktywności dzieci, młodzieży oraz dorosłych osób niewidomych i głuchoniewidomych. Tymczasem osoby te warto angażować w wiele form plastycznej kreacji, dodatkowo kierując się zasadą „im wcześniej, tym lepiej”. Tego typu doświadczenia mogą wspierać rozwój poznawczy, emocjonalny i społeczny osób z poważną dysfunkcją wzroku. Zostanie to wykazane na podstawie analizy literatury przedmiotu oraz poprzez przytoczenie studiów przypadków głuchoniewidomych uczestników plenerów rzeźbiarskich w Orońsku.Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00
A thermal investigation on coals from Assam (India)
A thermal characterization of two coal samples from Ledo and Tikak collieries of Makum
coalfield, Assam, India using XRD, FT-IR, and TGA was reported in this paper. The coal
samples were heated for 20, 40 and 60 min in a 1000-watt heater (temperature ∼250 °C) in
presence of air and characterized by XRD and FT-IR spectroscopy. Both the coals contain
amorphous and crystalline phases. The raw coals also contain very small peaks due to
quartz, calcite, gypsum, pyrite, and chlorite. The XRD patterns were found to change upon
heating. In the coals heated for 20 and 40 min, it was observed that both amorphous and
crystalline parts are common in them; crystalline part being the major one in the 40 min
heated samples. The XRD patterns of the samples heated for 60 min indicate the presence of
major quantities of α-quartz, hematite, and chlorite in them. They also show some new
peaks, which are assigned to be kaolinite, illite, magnetite and very small in comparison to
the amorphous portion in raw coals. α-quartz was found to be most stable crystalline phase
of silica in the coals. The crystallinity % (X-ray) of the coals heat-treated for different times
was determined and found to be increasing with time of heating. The FT-IR spectra of raw
and heat-treated coal samples at 250 °C were also recorded and compared. The spectra were
observed to be almost similar and it was observed that few functional groups disappear on
heating at 250 °C. The same coal samples were also characterized by thermogravimetric
analysis (TGA) and differential thermal analysis (DTA) techniques. On heat treatment in
air atmosphere up to 800 °C, 20–27% weight loss occurs due to removal of various
volatile materials. DTA results indicate the chemical reactivity of the coal sample initially
at 80–110 °C due to loss of water, and two other major reactions at around 420 and 530 °C
due to primary and secondary volatization
Racemic Resolution of some dl-Amino Acids using Aspergillus fumigatusl-Amino Acid Oxidase
The ability of Aspergillus fumigatus L-amino
acid oxidase (L-aao) to cause the resolution of racemic
mixtures of DL-amino acids was investigated with DL-alanine,
DL-phenylalanine, DL-tyrosine, and DL-aspartic acid.A
chiralcolumn,Crownpak CR?wasusedfortheanalysisof
the amino acids. The enzyme was able to cause the resolution
of the three DL-amino acids resulting in the production
of optically pure D-alanine (100% resolution),
D-phenylalanine (80.2%), and D-tyrosine (84.1%), respectively.
The optically pure D-amino acids have many uses
and thus can be exploited industrially. This is the first
report of the use of A. fumigatus L-amino acid oxidase for
racemic resolution of DL-amino acids
Solvent evaporation driven entrapment of magnetic nanoparticles in mesoporous frame for designing a highly efficient MRI contrast probe
The present work reports a novel strategy of assembling maghemite (?-Fe2O3) nanoparticles (NPs) in mesoporous silica host for developing a highly efficient MRI contrast probe. Shrinkage of hydrophobic environment due to the continuous evaporation of chloroform from Chloroform-in-Water emulsions pushes the hydrophobic ?-Fe2O3 NPs towards the hydrophobic pores of silica spheres resulting in a water soluble dense assembly structure. Mesoporous silica only with straight pores is found to be suitable for this particular entrapment process, while with curved and twisted pores, NPs are found to be seated on the surface only. So-developed assembly system has retained the superparamagnetic behaviour of its comprising NPs and exhibited high colloidal stability and biocompatibility. A significant enhancement in MRI transverse relaxivity to 386.2?mM?1?s?1 from 191.8?mM?1?s?1 of isolated primary ?-Fe2O3 NPs, has been obtained due to the strong magnetic field generated by the large number of NPs packed in the porous channels and consequent faster relaxation process. The fabrication strategy can be extended for the development of designed secondary nanostructures with new magnetic effects and physical properties
Development of Region Specific Hybrid Goat and their Performance Evaluation under High Altitude Condition
Goat meat (chevon) comprises an important source of protein to provide essential amino acids in addition to other meat and plant sources of proteins. Therefore, demands for chevon are huge from civil and defence sector in this region. However, there is limited availability of fresh tender chevon in Ladakh region round the year. Hence, there was a need of augmenting local availability of fresh goat meat by developing animal technology for fast growing region-specific crossbred goat for meat purpose that can efficiently perform under adverse climatic conditions prevailing in this region. The present crossbred goat was developed by using mixing genes of adaptive and meat traits through cross breeding between local goats (Changthangi and Gaddi breeds of goats) and Sirohi/Black Bengal goats. To develop this technology, we introduced Black Bengal and Sirohi from plain areas and native breed of goats viz. Gaddi and Changthangi goats for further adaptation and growth performance studies at Leh-Ladakh. After initial studies goats were divided into high altitude resistant/adapted and susceptible groups. High altitude resistant/adapted goats were taken for further cross breeding and pure breeding. All the kids produced out of this breeding were studied for physiological responses, growth performance, and blood biochemical parameters to know their adaptive and growth performance at high altitude. Crossbred kids of Sirohi ♂/Black Bengal ♂ X Changthangi ♀ had significantly (P<0.05) higher weight gain, adaptive physiological responses and blood biochemicals level as compared to exotic pure bred and other cross bred kids. These crossbred kids attained market weight faster than local as well as breeds from plain areas (Sirohi and Black Bengal goats). Average meat yield is 7-10 kg per adult crossbred goat if slaughtered at 9-12 month age. These cross bred (broiler goat) may be reared at Leh-Ladakh for meat purpose. Hence, this animal technology may help in increasing of fresh goat meat (chevon) supply to meet army’s and civil requirements in Leh-Ladakh
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