Two-photon excitation spectroscopy of 1,5--Diphenyl-1,3,5-hexatriene using phase modulation

We have used two-photon Fourier transform spectroscopy to investigate the first singlet excited state (S1) of a prototypical polyene molecule 1,5 -- Diphenyl-1,3,5-hexatriene. As the S1 state in the polyenes is a one-photon forbidden transition, its structure of the vibrational levels cannot be studied using resonant linear excitation. Although this level is accessible with two-photon excitation, previous studies done by using wavelength tunable pulsed lasers did not have enough resolution to investigate the details of the vibrational levels. In Fourier transform spectroscopy, one uses a pair of laser beams to excite the sample. The measurements are done by varying the time delay between the pulses. The spectral resolution is given by the inverse of the maximum time delay rather than the spectral width of the pulses. We have used the method to investigate the vibrational levels of the S1 state. In our implementation, we have used a phase modulation technique to carry out the measurements in the rotating frame, which require fewer data points along the time delay thereby significantly reducing the measurement time

Preferred orientation of n-hexane crystallized in silicon nanochannels: A combined x-ray diffraction and sorption isotherm study

We present an x-ray diffraction study on n-hexane in tubular silicon channels of approximately 10 nm diameter both as a function of the filling fraction f of the channels and as a function of temperature. Upon cooling, confined n-hexane crystallizes in a triclinic phase typical of the bulk crystalline state. However, the anisotropic spatial confinement leads to a preferred orientation of the confined crystallites, where the crystallographic direction coincides with the long axis of the channels. The magnitude of this preferred orientation increases with the filling fraction, which corroborates the assumption of a Bridgman-type crystallization process being responsible for the peculiar crystalline texture. This growth process predicts for a channel-like confinement an alignment of the fastest crystallization direction parallel to the long channel axis. It is expected to be increasingly effective with the length of solidifying liquid parcels and thus with increasing f. In fact, the fastest solidification front is expected to sweep over the full silicon nanochannel for f=1, in agreement with our observation of a practically perfect texture for entirely filled nanochannels

Detection of Wormhole Attack using Hop-count and Time delay Analysis

Abstract- MANET, due to the nature of wireless transmission, has more security issues compared to wired environments. In this paper we specifically considering Tunneling attack which does not require exploiting any nodes in the network and can interfere with the route establishment process. Instead of detecting suspicious routes as in previous methods, we implement a new method which detects the attacker nodes and works without modification of protocol, using a hop-count and time delay analysis from the viewpoint of users without any special environment assumptions. The proposed work is simulated using OPNET and results showing the advantages of proposed work. Index Terms- Ad hoc network, hop-count analysis, network security, Tunneling attack

Effect of Silicon Crystal Size on Photoluminescence Appearance in Porous Silicon

The photoluminescence (PL) study in porous silicon (PS) with decreasing Si crystallites size among the pores was reported. The PL appearance is attributed to electronic confinement in columnar-like (or dotlike) structures of porous silicon. Three different pore diameter PS samples were prepared by electrochemical etching in HF-based solutions. Changes in porous silicon and Si crystallite size were studied by observing an asymmetric broadening and shift of the optical silicon phonons in Raman scattering. Fourier transform infrared spectroscopy (FTIR) was used to study the role of siloxene or other molecular species, for example, in the luminescence mechanism. This mechanism was further studied by thermal annealing of PS at different temperatures. The PL of PS sample annealed at ≥300°C for 1 hr shows that trap electronic states appear in the energy gap of the smaller nano-crystal when Si–O–Si bonds are formed. From the observation of PL, Raman, and FTIR spectroscopy, the origin of PL in terms of intrinsic and extrinsic properties of nanocrystalline silicon was discussed.</jats:p

ALTERNATIVE HERBAL DRUGS USED FOR TREATING HAIR DISEASE

Objective: The main objective of present study is to treat Alopecia. Alopecia areata is an unpredictable hair-loss condition. Alopecia is a dermatological disorder with psychosocial implications on patients with hair loss. Herbal systems of medicine have become increasingly popular in recent years. Medicinal plants have been used for the treatment of hair diseases since antiquity. Herbs such as turmeric, fenugreek, ginger, Cyperus rotundus (Nagarmotha), and holy basil are integral parts of ayurvedic formulations. Cyperus rotundus is a well-known ayurvedic herb with purported claims of hair growth promotion. Methods: Extracts are prepared by separating the soluble matter from vegetable tissues by the application of a suitable solvent such as alcohol, water, or ether. The resultant liquid is concentrated by evaporation to obtain a liquid extract or concentrated almost to dryness to obtain the solid extract and its volatile oil. Hair formulation of Cyperus rotundus belonging to family Cyperaceae in the form of herbal formulation (5% herbal cream and oil) was studied and it showed excellent hair growth activity with standard (2% minoxidil ethanolic solution) in Wister albino rats. Results: Hair growth initiation time was significantly reduced to half on treatment with the oil, as compared to control animals. The hair growth promoting effect was evaluated against the control, standard, and test animals at 0, 10, 15, and 20 days with the formulated hair oil and hair cream prepared from the volatile oil extracted from the Cyperus rotundus and the significant hair growth was observed, and the growth was compared with the standard drug used 2% solution of minoxidil. Conclusion: The results of treatment with oil were better than the positive control minoxidil 2% treatment. It holds the promise of potent herbal alternative for minoxidil. Keywords: Alopecia areata, Cyperus rotundus, Hair growth, Extracts, Herbal creams, Hair oil, Hair formulation, Ayurvedic, Cyperaceae.  ORCID iD: - http://orcid.org/0000-0002-0439-606

Hepatoprotective Effect of Carrot (Daucus carota L.) on Paracetamol Intoxicated Rats

Plant products play a crucial role in the hepatoprotection through its antioxidants property. Therefore, search for modern medicine of plant origin with this property has become a central focus on hepatoprotection today. This study investigated to search a new hepatoprotective agent from natural sources, the methanol extract of nutitional plant, Daucus carota leaves was tested against liver damage of albino rats. Levels of serum marker enzymes i.e. SGOT, SGPT (aminotransferases), ALP (alkaline phosphatase) and TB (total bilirubin) in serum respectively. The histopathological changes of liver sections were also compared with the respective controls. 30% paracetamol induced significant (

PHARMACOGNOSTIC AND PHARMACOLOGICAL ASPECT OF BACOPA MONNIERI - A REVIEW

It is said that the use of Bacopa monnieri for memory enhancement goes back 3000 years or more in India, when it was cited for its medicinal properties, especially the memory enhancing capacity, in the Vedic texts "Athar-Ved Samhila" (3:1) of 800 B.C. and in Ayurveda. In the folklore of Indian medicine, several herbs have been used traditionally as brain or nerve tonics. One of the most popular of these neurotonics is Bacopa monnieri, a well known memory booster. Brahmi has been administered at religious institutions to help students to enhance their memory for learning ancient, religious hymns.It is also used as cardio-tonic, tranquilizer and sedative, improves process of learning, Restores memory, enhances power of speech and imagination, diuretic and nervine tonic, anti stress, for nervous and mental strain, use in insanity, epilepsy, hysteria, aesthenia, nervous breakdown. It is a small, creeping succulent herb. The leaf and flower bearing stems are 10- 30 cm long and arise from creeping stems that form roots at the nodes with pale blue or pinkish white flowers belonging to  Family  Scrophulariaceae grown nearly banks of freshwater streams and ponds, paddy fields and other damp places. The chief Phyto-constituents present are brahmine, herpestine, alkaloids and saponins. Keywords: Ayurveda, Brahmi, memory booster, herb, neurotonics, tranquilizer.Â