Nonradiative relaxation and laser action in tunable solid state laser crystals

Room-temperature pulsed laser action was obtained in chromium-activated forsterite (Cr:Mg2SiO4) for both 532 and 1064 nm pumping. Free running laser emission in both cases is centered at 1235 nm and has a bandwidth of approximately 30 nm. Slope efficiency as high as 22 percent was measured. Using different sets of output mirrors and a single birefrigent plate as the intracavity wavelength selecting element tunability over the 1167 to 1268 nm spectral range was demonstrated. Continuous wave laser operation at room temperature was obtained for 1064 nm pumping from a CW Nd:YAG laser. The output power slope efficiency is 6.8 percent. The gain cross section is estimated to be 1.1 x 10 to the 19th sq cm. Spectroscopic studies suggest that the laser action is due to a center other than the trivalent chromium (Cr 3+), presumably the tetravalent chromium (Cr 4+) in a tetrahedrally coordinated site

The Effect of Raw Soybeans in Mixtures for Laying Hens on Egg Quality and Egg Shell Quality

The study was conducted on hens at the age of 49 - 57 weeks to identify opportunities for replacing, with raw grain, thermally processed soybean Lana variety with a reduced level and Lydia variety with a standard level of trypsin inhibitor. The effect of using different levels of participation of both varieties of raw soybean in mixtures for layers on egg quality and eggshell quality was examined. The research was conducted according to the principle of two-factorial experiment (2 varieties x 4 levels of participation of raw soybeans). The average values of properties of the external and internal egg quality were under statistically significant influence of the level of participation of raw soybean in the mixture. Share of 8 % of raw soybeans of both varieties in diets for layers influenced significantly lower eggshape index, albumen height and Haugh's unit in relation to the mixture with a lower level of participation of raw soybeans. Yolk color and eggshell firmness were not significantly influenced by the studied factors

Tetravalent Chromium (Cr(4+)) as Laser-Active Ion for Tunable Solid-State Lasers

During 10/31/92 - 3/31/93, the following summarizes our major accomplishments: (1) the self-mode-locked operation of the Cr:forsterite laser was achieved; (2) synchronous pumping was used to mode lock the forsterite laser resulting in picosecond pulses, which in turn provided the starting mechanism for self-mode-locking; and (3) the pulses generated had a FWHW of 105 fs and were tunable between 1230 - 1270 nm

Tetravalent Chromium (Cr(4+)) as Laser-Active Ion for Tunable Solid-State Lasers

During 10/31/91 - 3/31/92, the following summarizes are major accomplishments: (1) numerical modeling of the four mirror astigmatically compensated, Z-fold cavity was performed; and (2) the simulation revealed several design parameters to be used for the construction of a femtosecond forsterite laser

Tetravalent chromium (Cr(4+)) as laser-active ion for tunable solid-state lasers

Major accomplishments under NASA grant NAG-1-1346 are summarized. (1) numerical modeling of the four mirror astigmatically compensated, Z-fold cavity was performed and several design parameters to be used for the construction of a femtosecond forsterite laser were revealed by simulation. (2) femtosecond pulses from a continuous wave mode-locked chromium doped forsterite laser were generated. The forsterite laser was actively mode-locked using an acousto-optic modulator operating at 78 MHz with two Brewster high dispersion glass prisms for intra-cavity chirp compensation. Transform-limited sub-100-fs pulses were routinely generated in the TEM(sub 00) mode with 85 mW of continuous power tunable over 1230-1280 nm. The shortest pulses of 60-fs pulsewidth were measured. (3) Self-mode-locked operation of the Cr:forsterite laser was achieved. Synchronous pumping was used to mode lock the forsterite laser resulting in picosecond pulses, which in turn provided the starting mechanism for self-mode-locking. The pulses generated had an FWHM of 105 fs and were tunable between 1230-1270 nm. (4) Numerical calculations indicated that the pair of SF 14 prisms used in the cavity compensated for quadratic phase but introduced a large cubic phase term. Further calculations of other optical glasses indicated that a pair of SFN 64 prisms can introduce the same amount of quadratic phase as SF 14 prisms but introduce a smaller cubic phase. When the SF 14 prisms were replaced by SFN 64 prisms the pulsewidth was reduced to 50 fs. Great improvement was observed in the stability of the self mode-locked forsterite laser and in the ease of achieving mode locking. Using the same experimental arrangement and a new forsterite crystal with improved FOM the pulse width was reduced to 36 fs

Tetravalent chromium (Cr(4+)) as laser-active ion for tunable solid-state lasers

Generation of femtosecond pulses from a continuous-wave mode-locked chromium-doped forsterite (Cr(4+):Mg2SiO4) laser has been accomplished. The forsterite laser was actively mode-locked using an acousto-optic modulator operating at 78 MHz with two Brewster high-dispersion glass prisms for intra-cavity chirp compensation. Transform-limited sub-100-fs pulses were routinely generated in the TEM(sub 00) mode with 85 mW of continuous power (with 1 percent output coupler), tunable over 1230-1280 nm. The shortest pulses of 60-fs pulsewidth were measured

Correlations Between Incidence of Foot Pad Lesions and Body Weight of Broilers in Different Rearing Systems

The incidence of foot pad lesions of broilers of moderate growth was investigated in order to establish correlations with body weight. Broilers were reared until the age of 42 days in the floor system in the poultry house and then were divided into two groups. The first group continued growing in the poultry house until the age of 84 days and the second group was growing in the free range system until the same age. Individual measurements of body weight and evaluation of the incidence of foot pad lesions of broilers were carried out at the end of the experiment. In a correlation analysis of previously transformed data on the percentage of broilers with lesions and body weight within each weight group, data were obtained that showed an association between these traits depending on the rearing system. System of rearing had significant impact on the strength and direction of correlation between body weight and the incidence of foot pad lesions, in light of the determined correlation coefficient r = -0.95 at the significance level p=0.01 in the free range system, and r=0.56 (p>0.05) in chickens reared in the poultry house

Efekat dodavanja enzima proteaze na masu i udeo jestivih pratećih proizvoda klanja pilića

This study evaluates the effect of protease supplementation of reduced crude protein diet for broilers on the weight of edible slaughter by-products (liver, gizzard, heart and abdominal fat) and their proportion in the body weight of birds at slaughter in two broiler genotypes – fast-growing Cobb 500 and slow-growing Master Gris. Protease (Ronozyme ProAct) was added at a concentration of 0.2% (E-I group) and 0.3% (E-II group), allowing reduction in crude protein level by 4% and 6%, respectively (through reduced soybean meal content). The length of the fattening period was 49 days. The results show somewhat greater differences in the weight and proportion of edible slaughter by-products between the hybrids and a similar response to dietary treatments by broilers from the three experimental groups in both hybrids, given their similar weights of edible slaughter by-products (heart, gizzard and abdominal fat) and their proportions in the body weight of birds at slaughter (significance was observed only in liver weight in Cobb 500 - P<0.05).U radu su analizirani efekti dodavanja enzima proteaze u hranu za piliće u tovu, uz smanjen nivo sirovih proteina, na masu jestivih pratećih proizvoda klanja (jetre, bubca, srca i abdominalne masti) i njihov udeo u masi grla pre klanja kod dva tovna hibrida – brzorastućeg Cobb 500 i spororastućeg Master Gris. Enzim proteaza (Ronozyme ProAct) dodat je u koncentraciji 0,2% (O-I grupa) i 0,3% (O-II grupa) uz istovremeno smanjenje sadržaja sirovih proteina za 4%, odnosno za 6% (preko smanjenog učešća sojine sačme). Tov pilića trajao je 49 dana. Na osnovu rezultata iz ovih istraživanja, može se zaključiti da su se nešto veće razlike u masi i udelu jestivih pratećih proizvoda klanja ispoljile između ispitivanih hibrida, a da su pilići iz sve tri ogledne grupe kod oba hibrida slično reagovali na primenjene tretmane ishrane, shodno tome da su imali približno iste mase jestivih pratećih proizvoda klanja (srca, bubca i abdominalne masti), kao i udele svih delova u masi grla pre klanja (značajnost se pojavila samo u masi jetre kod hibrida Cobb 500 - P<0,05)

The fusion protein SS18-SSX1 employs core Wnt pathway transcription factors to induce a partial Wnt signature in synovial sarcoma.

Expression of the SS18/SYT-SSX fusion protein is believed to underlie the pathogenesis of synovial sarcoma (SS). Recent evidence suggests that deregulation of the Wnt pathway may play an important role in SS but the mechanisms whereby SS18-SSX might affect Wnt signaling remain to be elucidated. Here, we show that SS18/SSX tightly regulates the elevated expression of the key Wnt target AXIN2 in primary SS. SS18-SSX is shown to interact with TCF/LEF, TLE and HDAC but not β-catenin in vivo and to induce Wnt target gene expression by forming a complex containing promoter-bound TCF/LEF and HDAC but lacking β-catenin. Our observations provide a tumor-specific mechanistic basis for Wnt target gene induction in SS that can occur in the absence of Wnt ligand stimulation

On the Theory of Vibronic Laser

Some aspects of lasing at vibronic transitions in impurity crystals are theoretically studied. The threshold conditions for a vibronic laser are shown to be dependent on the strength of interaction of optical centers with a local vibration, which forms the vibronic spectrum, and the crystal lattice temperature. The theory can be easily generalized to the spectrum containing a structureless phonon sideband and well agrees with the experimental temperature dependence of the output power of a Mg2SiO4:Cr4+ forsterite laser.Comment: 6 pages, 1 figur