A PV installation framework concerning electricity variable rates

This paper assesses building integrated photovoltaic (BIPV) installation parameters based on the profit generated by a photovoltaic system. It takes into consideration a home building case study and it investigates its monthly energy demand based on a specific location and a typical occupancy. The capability of a photovoltaic (PV) system to generate more profit occurs when solar intensity is maximum while the electric energy price is at its highest rate. The paper traces a framework that encompasses different aspects such as energy demand, energy price, and solar intensity. This framework identifies profit alternatives according to different installation parameters. A tool that predicts a PV installation hourly electric energy production is developed. The profit generated is simulated for home buildings located in Beirut (Lebanon) and Xihua (China), both at 33.8° latitude north. The paper highlights a new approach for BIPV installations, taking into account weather conditions, energy demand, and electric energy utility rates.     

An in situ TEM study of phase formation in gold-aluminum couples

In the gold wire bonding of aluminum in microelectronic devices the presence of aluminum oxide on the metallization surface may be expected. Electron transparent couples containing an oxide layer at the interface were heated in a TEM to determine the effects of a passivation layer on intermetallic formation. Intermetallic phases were evidenced by changes in sample appearance and their structure was determined by electron diffraction. The presence of an oxide at the interface hindered second phase formation at temperatures at which they were usually expected to form. In aluminum rich couples, the formation of the AuAl₂ intermetallic was not observed to form until about 350°C with the oxide present. In a reverse configuration involving a gold rich couple, an amorphous oxide phase was observed between the Al and the advancing Au₂Al front. The movement of the reaction front appeared to be controlled by surface diffusion across this phase.     

Biapenem versus imipenem/cilastatin in the treatment of complicated intra-abdominal infections: report from a Swedish Study Group

The objective of this study is to describe usual medical management and costs associated with recurrent respiratory infections in subjects with chronic obstructive bronchitis in France. A prospective survey was performed in Autumn 1994 on a national sample of private practice pulmonologists (N = 71). Two hundred forty-four patients, presenting at least one infection of the lower respiratory tract, were included. Bronchitis was the most frequent acute exacerbation observed (94%). Pneumonia concerned 9% of the patients. Biological tests, X-rays and pulmonary function tests were prescribed for, respectively, 59, 65 and 45% of the patients. Following the visit, 15 patients were hospitalized (6%). The direct medical cost per acute exacerbation was estimated 3,289 francs (1994 value) of which 60% were hospital-related. An average 10.4 day sick-leave was prescribed to 21% of patients in employment. For those patients, this sick-leave was associated to an extra-cost of 1,264-1,876 francs for Social Security and of 0-2,553 francs out of pocket per episode varying according to their Benefit Regimen.     

Rooster testicular germ cells and epididymal sperm contain P450 aromatase

We recently found that cytochrome P450 aromatase (P450arom) is present in germ cells of the mammalian testis and is capable of converting androgens to estrogens in the male reproductive tract. The objective of the present study was to determine whether testicular germ cells and epididymal sperm of an avian species are also capable of synthesizing estrogen. P450arom was localized in the rooster testis and epididymal region by immunocytochemistry, using an antiserum generated against purified human placental cytochrome P450arom. Immunostaining was present in pachytene spermatocytes, round spermatids, elongated spermatids, flagella of late spermatids, and sperm in the epididymal region. A positive reaction was also found in nonciliated cells of the epididymal region. However, the absence of mRNA for P450arom in the epididymal region indicated that the immunoreactive protein present in the epididymal region is not synthesized in this region. The immunoreactive P450arom found in epididymal sperm was shown to be active through use of a 3H2O assay. On the basis of these data, we conclude that rooster testicular germ cells and epididymal sperm are sites for the synthesis of estrogen, a potential regulator or modulator of germinal epithelium in the testis and the epithelium of the epididymal region of the avian species.     

Quick simulation of detector error probabilities in the presence ofmemory and nonlinearity

One would like to compare and analyze digital communication systems based upon their overall probability of error. Unfortunately, easily evaluated closed form expressions for these probabilities are almost impossible to derive due to the complexity of the stochastic systems usually encountered. Hence, one must often resort to simulation to obtain the desired quantities. The most obvious technique is Monte Carlo simulation, which directly counts the number of errors in repeated trials. The problem is that error probabilities are usually quite small, requiring numerous simulation runs to sufficiently “hit” the rare event to gain adequate knowledge of its statistics. This places severe demands on the computer's random number generator. Importance sampling strategies simulate under altered input signal distributions (e.g., translation or stretching) so as to “speedup” convergence of the error estimators. The authors discuss a speedup technique termed quick simulation based upon results in large deviation theory. The quick simulation method is shown to compare favorably with three other importance sampling techniques for simulating a simple nonlinear system with memory     

Effect of feedback from peripheral movements on neuron activity in the aplysia abdominal ganglion

We have made reasonably comprehensive measurements of action potential activity in the Aplysia californica abdominal ganglion to determine the amount of feedback the central nervous system (CNS) receives from a movement which it initiates. Voltage-sensitive dye measurements of action potential activity of cells in the ganglion were made during the gill-withdrawal reflex elicited by siphon stimulation. We compared recordings in two situations which differed dramatically in the amount the gill moved. In the control sea water, the gill withdrawal was normal; in low-Ca2+, high-Mg2+ sea water, the gill movement was blocked. Both the timing and the number of spikes of the individual neurons were similar in the two situations. Histograms of the summed spike activity versus time and histograms of the number of active neurons versus time in the two conditions were also similar. Finally, two numerical measures of trial-to-trial differences, a paired t-test and a measure we named fractional similarity, did not indicate larger differences between two trials in the different sea waters than two trials in the same sea water. Feedback from sensory neurons activated by the gill movement itself does not make a large contribution to the spike activity in the abdominal ganglion. Apparently the Aplysia CNS issues the command for the withdrawal and does not make adjustments for the magnitude of the actual withdrawal. It may not even receive the information necessary for such adjustments to be made. A second motivation for these experiments was to test whether removing the feedback might simplify the neuronal activity that occurs during the gill-withdrawal reflex. This did not occur.     

The Effect of Nonuniform Chemistry on Interfacial Fracture Toughness

The adhesion of metallic-ceramic interfaces is generally ascribed to the mixture of several mechanisms, including chemical bonding, texture, strain transfer, and plasticity. This study examines the impact of alterations in chemical bonding along an interface on the nanometer scale on the interfacial fracture energy. Using a well-characterized system of W/SiO₂, small areas of the interface were masked with polymer tubes to prohibit the area from adhering well to the W film. This showed that the interfacial fracture energy was proportional to the area of higher adhesion. This finding was then used to study the growth of a Ti interlayer used for adhesion promotion in a Pt/SiO₂ system. Because the adhesion energy slowly grew from values near the Pt/SiO₂ to values typical of Ti/SiO₂, the growth mechanism for DC magnetron sputtering of thin film Ti on SiO₂ was inferred to be island growth instead of layer-by-layer growth. This article is based on a presentation given in the symposium entitled “Deformation and Fracture from Nano to Macro: A Symposium Honoring W.W. Gerberich’s 70th Birthday,” which occurred during the TMS Annual Meeting, March 12–16, 2006 in San Antonio, Texas and was sponsored by the Mechanical Behavior of Materials and Nanomechanical Behavior Committees of TMS.     

Dysregulated CD38 Expression on Peripheral Blood Immune Cell Subsets in SLE

Given its uniformly high expression on plasma cells, CD38 has been considered as a therapeutic target in patients with systemic lupus erythematosus (SLE). Herein, we investigate the distribution of CD38 expression by peripheral blood leukocyte lineages to evaluate the potential therapeutic effect of CD38-targeting antibodies on these immune cell subsets and to delineate the use of CD38 as a biomarker in SLE. We analyzed the expression of CD38 on peripheral blood leukocyte subsets by flow and mass cytometry in two different cohorts, comprising a total of 56 SLE patients. The CD38 expression levels were subsequently correlated across immune cell lineages and subsets, and with clinical and serologic disease parameters of SLE. Compared to healthy controls (HC), CD38 expression levels in SLE were significantly increased on circulating plasmacytoid dendritic cells, CD14⁺⁺CD16⁺ monocytes, CD56⁺ CD16^dim natural killer cells, marginal zone-like IgD⁺CD27⁺ B cells, and on CD4⁺ and CD8⁺ memory T cells. Correlation analyses revealed coordinated CD38 expression between individual innate and memory T cell subsets in SLE but not HC. However, CD38 expression levels were heterogeneous across patients, and no correlation was found between CD38 expression on immune cell subsets and the disease activity index SLEDAI-2K or established serologic and immunological markers of disease activity. In conclusion, we identified widespread changes in CD38 expression on SLE immune cells that highly correlated over different leukocyte subsets within individual patients, but was heterogenous within the population of SLE patients, regardless of disease severity or clinical manifestations. As anti-CD38 treatment is being investigated in SLE, our results may have important implications for the personalized targeting of pathogenic leukocytes by anti-CD38 monoclonal antibodies.