The impact of a monensin controlled-release capsule on subclinical ketosis in the transition dairy cow

An experiment was designed to examine subclinical ketosis in periparturient dairy cows and the antiketogenic effects of monensin. Subclinical ketosis was induced through a 10% feed restriction and was quantitatively determined using a blood beta-hydroxybutyrate (BHBA) threshold of 1200 mumol/L. Monensin decreased the BHBA concentration by 35% and increased the glucose concentration by 15%. No effect of monensin on milk production was detected, but rumen fermentation was altered. Monensin decreased the acetate to propionate ratio, decreased the butyrate concentration, and increased pH. The lower concentration of BHBA in blood and higher concentration of blood glucose in cows treated with a monensin controlled-release capsule decreased subclinical ketosis in early lactation cows.     

Tunable Thermo‐Responsive Poly(N‐vinylcaprolactam) Cellulose Nanofibers: Synthesis,Characterization, and Fabrication

Temperature‐responsive PVCL homopolymers and functional PVCL polymers containing carboxylic acids are prepared in organic and aqueous solutions. PVCL bulk polymers are characterized using ¹H NMR, photometry, ATR‐FTIR, and thermal analysis. A finite phase transition at 37–40 °C occurs in aqueous solutions of PVCL and PVCL‐COOH. PVCL and PVCL‐COOH polymers are electrospun into fibers ranging from 100 to 2300 nm in diameter. PVCL/cellulose bi‐component films are obtained by electrospinning of CA and PVCL followed by alkaline hydrolysis. These tunable thermo‐responsive PVCL/cellulose nanofibers have potential applications in developing affinity membranes.

     

碱改性Hβ分子筛催化酯交换合成草酸二苯酯

研究了以KOH碱改性Hβ分子筛为催化剂,苯酚和草酸二甲酯(DMO)酯交换合成草酸二苯酯(DPO)反应。通过对催化剂进行吸附吡啶的IR光谱和NH3-TPD测试,对催化剂的表面状态和性质进行了表征。结果表明,弱酸中心的酸强度改变不影响苯甲醚选择性,只有强酸中心的酸强度减弱或酸量减少才使苯甲醚选择性降低。当用少量的KOH改性Hβ时,强酸中心酸量和酸强度不变,只是弱酸中心酸强度进一步减弱,所以苯甲醚选择性不变。同时因为K2O活性中心和酸中心协同催化作用,DMO转化率增加。当K负载量增大到0．32％时,强酸中心消失,苯甲醚选择性显著降低．但因为弱酸中心同时大量减少导致了DMO转化率的降低。当K负载量为0．04％时,K改性Hβ催化剂催化性能相对较好,DMO转化率62．4％,MPO,DPO和苯甲醚选择性分别为51．8％,14．8％,30．2％,MPO和DPO收率分别为32．3％,9．2％。     

An experimental study of spouting in large sector beds

In a sector spouted bed, fluid is introduced into the bottom at the junction of two vertical walls, the bed forming a sector in horizontal cross-section. The hydrodynamics of beds of 30° sector angle have been studied in equipment of radius up to 0.78 m. The spout radius is greater than would be predicted from standard correlations on small circular beds. The overall pressure drop can be less than 20% of that found for minimum fluidisation. The vertical pressure distribution is given approximately by a quarter cosine function. Minimum spouting velocity decreases with increasing size of bed, loss of spouting being caused by a decrease in fountain height followed by snuffing of the spout by annular solids.     

16.4% efficient, thin active layer silicon solar cell grown by liquid phase epitaxy

An energy conversion efficiency of 16.4% is reported for a silicon solar cell of 4.11 cm² total area with a thin active layer of 32 μm grown by liquid phase epitaxy (LPE). This is the highest ever total area efficiency for a cell of this type and is due to a number of improvements over earlier reported results. The thin active layer was grown by LPE on an inactive silicon substrate from an indium solution in a 20% hydrogen/argon forming gas mixture ambient rather than pure hydrogen. Higher current density and efficiency than previously reported for similar cell structures have been achieved by employing microgroove texturing of the front surface, a very shallow (0.25 μm) and high sheet resistivity (220 Ω□) top surface phosphorus diffusion, an optimized ZnS/MgF₂ double layer antireflection coating on top of a 200Å thick, high quality passivation SiO₂ layer, a large aspect ratio (0.45) for the metal contacts, and a graded doping level within the 32 μm thick LPE active layer. The effect of the improved techniques on the cell performance and the properties of the thin active layers are discussed.     

Using wireless technology to develop a virtual reality command and control centre

This paper investigates the applicability of wireless communication systems for use in command and control environments. Human positional data is transmitted over a wireless network. This data is then used to update a highly accurately modelled real-time 3D environment of the surroundings, with avatars positioned at the transmitted points. The data is displayed on a stereoscopic 3D screen enabling novel automatic tracking of human movement and allowing for more rapid and informed tactical decision making. The system has applicability in a variety of C4I environments, including the military and emergency services.     

A lower bound for monotone perceptrons

It is proved that there is a monotone function in AC ₄ ⁰ which requires exponential-size monotone perceptrons of depth 3. This solves the monotone version of a problem which, in the general case, would imply an oracle separation of PP^PH.     

Conserving One Water Source at the Expense of Another: The Role of Surface Water Price in Adoption of Wells in a Conjunctive Use System

One potential side-effect of irrigation water rate reform is groundwater substitution. As surface water prices rise, irrigators may find it cheaper to rely on on-farm wells than a regional irrigation district. The impact of surface water price on well adoption is examined in a conjunctive use system where both surface water and groundwater are used to meet irrigator demand. Results indicate that as the price of surface water approaches 62% of the marginal cost of pumping groundwater, irrigators are more likely to have on-farm pumping capabilities. This result suggests that proposed water rate reforms by the United States Bureau of Reclamation may result in irrigators substituting groundwater for surface water by adopting on-farm wells.     

The natural product noformycin is an inhibitor of inducible-nitric oxide synthase

Inducible-Nitric oxide synthase (iNOS, EC 1.14.13.39) catalyzes the formation of nitric oxide (NO) and L-citrulline from L-Arg. NADPH and dioxygen. The natural product, (-)-noformycin was found to be a potent, competitive inhibitor of recombinant human iNOS with respect to L-Arg with a Ki = 1.3 +/- 0.3 microM. The reversible binding of noformycin caused a high spin type I spectral perturbation of the iNOS heme group with a Kd = 1.5 +/- 0.2 microM. These results demonstrate that natural products may be a useful source for inhibitors of NO-biosynthesis.