Pressure anomaly in the paramagnetic region of bcc solid3He

The isochoric pressure of bcc Solid³He in the vicinity of the triple point has been measured by changing the temperature stepwisely and waiting for thermal equilibrium. We observed anomalous pressure kinks of the temperature dependence in the paramagnetic region near the triple point. This anomaly appeared at 0.37 to 0.40 tesla, and disappeared below 0.36 tesla. Moreover, critical phenomena at the transition point from the paramagnetic phase (PP) to the high field phase was observed and the phase line curves toward the PP side.     

Pool Boiling Enhancement through Graphene and Graphene Oxide Coatings

ABSTRACT

Boiling has served as an effective means to dissipate large quantities of heat over small areas. Graphene, a two-dimensional material, has garnered significant attention of researchers due to its excellent thermal properties. In this study, copper test chips are dip coated with a solution consisting of graphene oxide and graphene and its pool boiling performance with distilled water at atmospheric pressure was investigated. The surfaces were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy which confirmed the presence of graphene and graphene oxide. The contact angles measured on the coated surfaces indicated hydrophobic wetting behavior. Four heat transfer surfaces were prepared with dip coating durations of 120 s, 300 s, 600 s, and 1200 s, respectively. A Critical Heat Flux (CHF) of 182 W/cm² and a heat transfer coefficient (HTC) of 96 kW/m²°C was obtained with the shortest coating duration which translated to an enhancement of 42% in CHF and 47% in HTC when compared to a plain uncoated surface under similar conditions. Contact angle changes were not seen to be responsible, although roughness was seen as an influencing factor contributing to the enhancement. Further studies are needed to explain the enhancement mechanism.     

Beyond fathering behaviors: Types of dads.

Sixty-nine maritally intact, middle-class Caucasian families rearing their 15-month-old firstborn male child participated in a study of fathering. Two 1-hr naturalistic home observations per family were conducted near dinnertime to record father-child interactions, which were then used to rate father involvement. Cluster analysis of fathering ratings revealed 4 groups of dads: caretakers, playmates-teachers, disciplinarians, and disengaged fathers. Information on demographics, personality, marital quality, relatedness, moods and hassles, and infant emotionality was gathered via parental reports. Analysis of antecedent variables indicated that the caretaker and playmate-teacher fathers were more educated, had more prestigious occupations, were less neurotic, had more confidence in the dependability of others, and experienced fewer daily hassles than the disciplinarian and disengaged fathers. Discriminant analysis demonstrated the collective ability of the antecedent variables to distinguish the 4 groups of fathers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phosphotungstic Acid: An Efficient Catalyst for the Aqueous Phase Synthesis of Bis-(4-hydroxycoumarin-3-yl)methanes

In this present work, we report that phosphotungstic acid provides a simple, efficient and environmentally benign route is a two-component one-pot domino Knoevenagel-type condensation/Michael reaction between 4-coumarin derivative and an aldehyde in water as a solvent in shorter duration with high yields.      

Relationship between physicochemical and rheological properties of starches from Indian wheat lines

Starches from nine Indian wheat lines were evaluated to study the relationships between physicochemical and rheological properties. Large granules (>15 μm) were present in the highest proportion followed by medium (5–15 μm) and small granules (<5 μm). Amylose content ranged between 27.4 and 37.2%. Starch with the highest proportion of large granules (68.9%) showed higher values of G′_peak (576 Pa) and G′_final (432 Pa). Amylose content showed positive relationships with retrogradation, gel firmness, gumminess and adhesiveness while negative with springiness. Cooked starch pastes with the highest amylose content (37.2%) had higher ΔH_ret (0.88 J g^?1), G′_ret (361 Pa), adhesiveness (1.48 Ns), firmness (0.45 N) gumminess (0.22 N) and the lowest springiness (0.88). Amylose–lipid complex (AML) dissociation showed negative relations with swelling power, G′_peak, G′_breakdown and breakdown viscosity (r = ?0.779, ?0.66, ?0.771 & ?0.775, respectively, P < 0.05) while positive relationship with pasting temperature (r = 0.775, P < 0.05).     

Differential roles of T cell receptor alpha and beta chains in ligand binding among H-2Kd-restricted cytolytic T lymphocyte clones specific for a photoreactive Plasmodium berghei circumsporozoite peptide derivative

To study the interaction of T cell receptor with its ligand, a complex of a major histocompatibility complex molecule and a peptide, we derived H-2Kd-restricted cytolytic T lymphocyte clones from mice immunized with a Plasmodium berghei circumsporozoite peptide (PbCS) 252-260 (SYIPSAEKI) derivative containing photoreactive Nepsilon-[4-azidobenzoyl] lysine in place of Pro-255. This residue and Lys-259 were essential parts of the epitope recognized by these clones. Most of the clones expressed BV1S1A1 encoded beta chains along with specific complementary determining region (CDR) 3beta regions but diverse alpha chain sequences. Surprisingly, all T cell receptors were preferentially photoaffinity labeled on the alpha chain. For a representative T cell receptor, the photoaffinity labeled site was located in the Valpha C-strand. Computer modeling suggested the presence of a hydrophobic pocket, which is formed by parts of the Valpha/Jalpha C-, F-, and G-strands and adjacent CDR3alpha residues and structured to be able to avidly bind the photoreactive ligand side chain. We previously found that a T cell receptor specific for a PbCS peptide derivative containing this photoreactive side chain in position 259 similarly used a hydrophobic pocket located between the junctional CDR3 loops. We propose that this nonpolar domain in these locations allow T cell receptors to avidly and specifically bind epitopes containing non-peptidic side chains.     

Electromagnetic interference shielding behavior of poly(trimethylene terephthalate)/multi-walled carbon nanotube composites

Poly(trimethylene terephthalate) [PTT]/multiwalled carbon nanotube [MWCNT] composites having varying amounts of MWCNTs were fabricated with an aim to investigate the potential of such composites as an effective light weight electromagnetic interference (EMI) shielding material in the frequency range of 12.4-18 GHz (Ku-band). PTT/MWCNT composite with shielding effectiveness (SE) of 36-42 dB was obtained at 10% (w/w) MWCNT loading. Shielding mechanism was studied by resolving the total SE into absorption (SE_A) and reflection loss (SE_R). PTT/MWCNT composite showed absorption dominated shielding; thus it can be used as microwave, radar absorbing and stealth material. The effect of MWCNT loadings on electrical conductivity (σ) and dielectric properties of PTT and the correlation among conductivity, tan δ, absorption loss and reflection loss were also studied.     

Radical polymerization of acrylonitrile initiated by α-picolinium p-chlorophenacylid

The radical polymerization of acrylonitrile (AN) with α-picolinium p-chlorophenacylid (α-PCPY) as initiator using carbon tetrachloride as inert solvent was investigated at 50°C. The polymerization follows ideal kinetics: the exponent values calculated for the initiator and monomer were found to be 0.5 and unity, respectively. A free radical mechanism with bimolecular termination was confirmed by the inhibiting effect of hydroquinone, a radical quencher. The rate of polymerization was a direct function of initiator (α-PCPY) concentraction, monomer (AN) concentration and temperature. The overall activation energy calculated was 56 kJ/mol. The polymerization was favoured by polar solvents and retarded by non-polar solvents.