Autothermal reforming of methane over Ni/γ-Al2O3 promoted with Pd: The effect of the Pd source in activity,temperature profile of reactor and in ignition

The effects of adding small amounts of palladium to Ni/γ-Al₂O₃ catalysts for the autothermal reforming of methane, in terms of activity, reducibility, capacity of repeated ignition and temperature profile of the reactor are described. The effect of different Pd sources was also studied. The Pd addition favors nickel reduction at lower temperatures. When the palladium is added as PdCl₂ (PdNiAl-Cl) it exhibits a higher reduction temperature than when Pd(NO₃)₂ (PdNiAl-N) is used, an this can be attributed to the formation of Pd_xCl_yO_z species. Palladium strongly increases the activity of the Ni catalyst in autothermal reforming of methane, which is proportional to an increase in metal surface area. The addition of palladium to the catalyst also leads to a flatter temperature profile through the catalytic bed in the autothermal reforming of methane, and this is assigned to the high surface metal area of the catalyst. Only PdNiAl-N catalyst catalyzes the autothermal reforming of methane without previous reduction, while the PdNiAl-Cl catalyst only catalyzes the methane combustion and the unpromoted catalyst was inactive.     

Pentobarbitone premedication for anaesthesia. The influence of the preparation and route of administration on its clinical action

Studies were carried out in the pre-operative period on patients premedicated with 100 mg pentobarbitone given by mouth or by intramuscular injection into the buttock. The injections were given by doctors using a 4 cm needle or by nurses using the needle of their choosing and two preparations were used. One was a freshly prepared aqueous solution and the other the commercially available organic solution (Nembutal) with propylene glycol, alcohol and water as solvents. An unacceptably high incidence of persistent injection site pain occurred after the use of the organic preparation but not with the aqueous solution. Otherwise no difference was detected between the effects of the two preparations. Drugs injected by doctors were, on the whole, more effective as premedicants than those injected by nurses. Oral pentobarbitone was not as effective a premedicant as the intramuscular preparation and its anxiolytic action did not differ from that of the placebo. Relief of apprehension was disappointing with all preparations of 100 mg pentobarbitone and was not as good as with diazepam. This may be attributed to the use of too small doses but larger injection volumes would have caused their own problems.     

2DT-FP: A parallel functional programming language on two-dimensional data

We propose a new paradigm for programming multiprocessor systems, 2DT (two-dimensional transformations). 2DT programs are composed of local computations on linear data (columns) and global transformations on 2-dimensional combinations of columns (2D-arrays). Local computations can be expressed in a functional or imperative base language; a typed variant of Backus' FP is chosen for 2DT-FP. The level of abstraction of 2DT makes it suitable for programming a relevant set of algorithms, in general any algorithms, whose data can be easily mapped to 2-dimensional representations. A set of examples tries to prove this claim. An interleaving semantics for 2DT-FP is given, exposing the potential for parallel execution of 2DT-FP programs. The claim is proved that any sequential and thus any parallel execution will deliver the same result. The implementation realized on the Intel Hypercube is described. Supported by the Deutsche Forschungsgemeinschaft, DFG     

Scaling model checking of dataraces using dynamic information

Dataraces in multithreaded programs often indicate severe bugs and can cause unexpected behaviors when different thread interleavings are executed. Because dataraces are a cause for concern, many works have dealt with the problem of detecting them. Works based on dynamic techniques either report errors only for dataraces that occur in the current interleaving, which limits their usefulness, or produce many spurious dataraces. Works based on model checking search exhaustively for dataraces and thus can reveal even those that occur in rarely executed paths. However, the applicability of model checking is limited because the large number of thread interleavings in realistic multithreaded programs causes state space explosion. In this work, we combine the two techniques in a hybrid scheme which overcomes these difficulties and enjoys the advantages of both worlds. Our hybrid technique succeeds in providing thread interleavings that prove the existence of dataraces in realistic programs. The programs we experimented with cannot be checked using either an ordinary industrial strength model checker or bounded model checking.     

Eco-Storage: A Hybrid Storage System with Energy-Efficient Informed Prefetching

In this paper, we present an energy-aware informed prefetching technique called Eco-Storage that makes use of the application-disclosed access patterns to group the informed prefetching process in a hybrid storage system (e.g., hard disk drive and solid state disks). Since the SSDs are more energy efficient than HDDs, aggressive prefetching for the data in the HDD level enables it to have as much standby time as possible in order to save power. In the Eco-Storage system, the application can still read its on-demand I/O reading requests from the hybrid storage system while the data blocks are prefetched in groups from HDD to SSD. We show that these two steps can be handled in parallel to decreases the system’s power consumption. Our Eco-Storage technique differs from existing energy-aware prefetching schemes in two ways. First, Eco-Storage is implemented in a hybrid storage system where the SDD level is more energy efficient. Second, it can group the informed prefetching process and quickly prefetch the data from the HDD to the SSD to increase the frequent HDD standby times. This will makes the application finds most of its on-demand I/O reading requests in the SSD level. Finally, we develop a simulator to evaluate our Eco-Storage system performance. Our results show that our Eco-Storage reduces the power consumption by at least 75 % when compared with the worst case of non-Eco-Storage case using a real-world I/O trace.     

Using the biophysical CHARMED model to elucidate the underpinnings of contrast in diffusional kurtosis analysis of diffusion-weighted MRI

Object

The aim of this work was to understand biophysical substrate underpinning contrast in diffusional kurtosis imaging (DKI) in white matter, using the composite hindered and restricted model of diffusion (CHARMED).

Materials and methods

A theoretical relationship between the kurtosis function K and the CHARMED parameters, i.e., the restricted volume fraction RF and the axonal longitudinal diffusivity D was derived for the propagator used in the CHARMED model. Evidence for a similar correlation between these measures was then investigated in vivo across different WM regions in five healthy young subjects that underwent a CHARMED protocol at 3T.

Results

Our theoretical treatment shows that K has an increasing trend for both increasing RF values and increasing D. In vivo, a significant positive correlation (P?K _⊥ and RF. A multilinear regression showed that K _⊥ values are better explained by a mixed contribution of both RF and D.

Conclusions

The CHARMED model was used to understand whether and where DKI contrast can be explained in terms of the underlying axonal geometry. This work demonstrates that the information contained in DKI overlaps with the information extracted by CHARMED in areas of higher intra-voxel directional coherence.     

Potential mucoadhesive dosage form of lidocaine hydrochloride: II. In vitro and in vivo evaluation

The aim of this study was to develop a controlled release buccal mucoadhesive delivery system for systemic delivery of lidocaine hydrochloride as a model drug. In vitro release and buccal permeation as well as in vivo permeation of LDHCL patches were evaluated. The drug release and the permeability of the drug through porcine buccal mucosa were evaluated using Franz diffusion cell. In vivo evaluation of patches was carried out on rabbits as an animal model. Patches were designed in two fashions, bi-layer (BLP; LDHCL, carbopol, glycerin, pentration enhancer, and Tween 20 as the first layer; and EVA as the second layer) and triple layer (TLP; LDHCL, carbopol and glycerin as the first layer; carbopol, glycerin, pentration enhancer and pluronic F-127 as the middle layer; and EVA as the third layer) patches, respectively. Presence of oleic acid as PE in the formulation significantly enhanced the in vitro permeability of LDHCL (p<0.05), while propylene glycol monolaurate as PE suppressed it (p<0.05). The in vivo evaluation in rabbits showed that TLP had significantly higher Cmax and AUC0-8 (p<0.05) than BLP. Furthermore, TLP showed a well-controlled drug plasma concentration over 6 hr which was significantly longer than BLP (p<0.05). Patches were well adhered to buccal mucosa of the rabbits over the 8-hr study period. It was postulated that the hypothetical release mechanism of the drug and oleic acid from TLP was controlled by their diffusion through the swollen polymer network and micelled gel.     

Diagnosis based on reliability analysis using monitors and sensors

We develop a process for using monitors or sensors to optimize diagnostic decision trees (DDTs) generated for large systems. We present algorithms for optimizing the diagnosis process, which combines evidence data captured from monitors or sensors into the diagnostic tree generation process to produce DDTs. Since evidence data can be extracted from monitors and sensors, we developed a method for sensor modeling. Our method allows modeling monitors or sensors as an abstract layer on top of a systems fault tree model. This method of modeling allows the designer to graphically link monitors or sensors to the components that they monitor, without impacting the reliability analysis. We use a real system from the industry to demonstrate the practicality and effectiveness of our algorithms and methods.     

Assessment of the Impact of Potential Climate Change on the Water Balance of a Semi-arid Watershed

With a yearly precipitation of 200 mm in most of the country, Jordan is considered one of the least water-endowed regions in the world. Water scarcity in Jordan is exacerbated by growing demands driven by population and industrial growth and rising living standards. Major urban and industrial centers in Jordan including the Capital Amman are concentrated in the northern highlands, mostly contained within the boundaries of the Zarqa River Watershed (ZRW). The ZRW is the third most productive basin in the greater Jordan River System. King Talal Dam was built a few kilometers upstream of the Zarqa-Jordan confluence to regulate its input mostly for the benefit of agricultural activities in the Jordan Valley. Concerns regarding the sensitivity of the ZRW to potential climate change have prompted the authors to carry out the current study. The methodology adopted is based on simulating the hydrological response of the basin under alternative climate change scenarios. Utilizing the BASINS-HSPF modeling environment, scenarios represent ing climate conditions with ±20% change in rainfall, and 1°C, 2°C and 3.5°C increases in average temperature were simulated and assessed. The HSPF model was calibrated for the ZRW using records spanning from 1980 through 1994. The model was validated against an independent data record extending from 1995 through 2002. Calibration and verification results were assessed based on linear regression fitting of monthly and daily flows. Monthly calibration and verifications produced good fit with regression coefficient r values equal to 0.928 and 0.923, respectively. Assessment based on daily records show much more modest r value of 0.785. The study shows that climate warming can dramatically impact runoffs and groundwater recharge in the ZRW. However the impact of warming can be greatly influenced by significant changes in rainfall volume.