Economics of liquid hydrogen from water electrolysis

Using the data from vendors and open literature, we have constructed a preliminary cost model to predict the cost of liquid hydrogen (LH₂) from water electrolysis. The model has been applied to two LH₂ plants. Both have a production rate of 10 886 kg day⁻¹. The first plant (Plant 1) consists of a tank-type electrolyzer and a liquefier and runs all day at the base-load (or equivalent base-load) power rate. The second (Plant 2) consists of a tank-type electrolyzer, a liquefier, a compressor, and storage vessels. The electrolyzer and the compressor shall run only during the off-peak hours at the off-peak power rate. However, the liquefier shall run all day at the base-load (or equivalent base-load) power rate. The costs of LH₂ from both plants are presented. Unless the base-load power rate is high and the off-peak power rate is substantially low, Plant 1 appears to be economically more feasible than Plant 2.     

Mechanical properties of poly(ether-ether-ketone) for engineering applications

An outline of the characteristics of PEEK and the versatility of its compositional forms (micro and macro composites) are given to illustrate its wide potential for success in engineering applications. Although it is necessary to have particular tabulations of mechanical properties for engineering design, these are seldom available and consequently it is argued that an understanding of stiffness, toughness and strength properties are required to fully exploit available manufacturer's data and thus develop the full potential of PEEK and its composites. Stiffness characteristics are considered in terms of a modulus function which is dependent on time under load and temperature. In its composite forms, whether reinforced with short or continuous fibres, stiffness anistropy can be both considerable and complex, but some empirical ground-rules are apparent. For continuous fibre composites even in the form of complex lay-ups, it is also possible to attempt some stiffness prediction from certain pseudo-elastic constants. Toughness of PEEK and its composites is described in terms of both comparative and intrinsic properties. Instrumented falling weight impact data, particularly as a function of temperature enable some insight into ductile-brittle transitions for the unreinforced material, but crack initiation and crack propagation processes for the various fibre reinforced forms. Intrinsic toughness is described in terms of linear elastic fracture mechanics theory. Strength properties are described for static and dynamic loading configurations. In particular, PEEK and its composites are evaluated for increasing test severities for strength characteristics; stress concentration, loading form and test temperature are considered.     

Use of pooled time series in the study of naturally occurring clinical events and problem behavior in a foster care setting.

Pooled time series is an underused analytic technique with the potential to increase researchers' ability to exploit clinical data. This article demonstrates the value of pooled time series by analyzing the behavior of youths in a specialized foster care treatment setting in response to a naturally occurring clinical event: changes in the number of youths living together in a treatment foster care setting. Pooled time series moves beyond typical clinical analyses with an increased capability of controlling statistically for complex within-S effects and with a clinically useful measure of effect size. The complexity of the intra-S data made it virtually impossible to determine the relevant significance (i.e., clinical meaning) of the clinical event by the use of standard n?=?1 visual analysis procedures or standard statistical methods (e.g., chi square). After things such as autocorrelation and individual time trends were statistically controlled, each additional youth increased the number of problematic behaviors by one behavior per youth per day on the Parent Daily Report. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prevalence of artificial hip implants and use of health services by recipients

Intraneural injection of 10-20 x 10(6) viable Mycobacterium leprae into the sciatic nerve of normal, unsensitized, Swiss white mice gives rise to a tuberculoid type of granulomatous response in 2 weeks. The same dose of viable M. leprae when injected into the sciatic nerves of unsensitized immunosuppressed mice (T200 x 5R) elicited a macrophage response. When macrophages were systemically immobilized using an intraperitoneal injection of silica quartz dust in normal mice, the lesion produced was of the lepromatous type, suggesting a role for the macrophage in the induction of the tuberculoid type of granulomatous response. In all of these in situ experiments, M. leprae failed to enter the Schwann cells.     

The putative tumor suppressor gene on chromosome 5q for hepatocellular carcinoma is distinct from the MCC and APC genes

We have previously shown that the tumor suppressor gene for hepatocellular carcinoma (HCC) without cirrhosis may be located on chromosome 5q35-qter. In this study, we analyzed nine cases of primary HCC without cirrhosis using probes from the MCC and APC genes, which are in the region 5q21-22. None of the informative cases had allele loss detected by these probes, whereas the probe lambda MS8 for the region 5q35-qter showed allele loss in six out of six informative cases. The results confirm that the putative tumor suppressor gene for HCC without cirrhosis on chromosome 5q is distinct from the MCC and APC genes.     

Prenatal care in the inner-city: a cooperative effort

PAHCF and Women and Infants Hospital have been working together for many years to provide high quality, accessible prenatal and obstetrical care to low-income, inner-city residents in the Providence area. Many of these patients have multiple medical, social, and nutritional problems that place them at increased risk for poor pregnancy outcomes. The PAHCF sites offer convenient locations, evening hours, and culturally-sensitive, bilingual staffs; together the five sites provided prenatal care to nearly 1200 patients last year. Women and Infants Ambulatory Care Department provided prenatal care to an additional 1800 women in 1991, including all high risk patients referred for complications or diagnostic evaluations. All patients deliver at Women and Infants, then return to their original source of care for postpartum followup and family planning services. Patient records are readily transferred between the sites, eliminating the need for unnecessary duplication of information or laboratory tests. This close collaboration is mutually beneficial to both the health care providers and the patients whom they serve.     

Ewing sarcoma. Diagnostic imaging

Ewing's sarcoma is a highly malignant neoplasm of the bone whose origin is still uncertain. A strong relationship exists between Ewing's sarcoma and tumors of neural origin (Ewing family of tumors). Ewing's sarcoma must be distinguished from other round-cell tumors like lymphoma and neuroblastoma and also must be differentiated from osteogenic sarcomas. On plain radiographs, Ewing's sarcoma appears as a lytic or mixed lytic-sclerotic, rarely as predominantly sclerotic lesion with margins Lodwick grade III. It is located primarily in the diaphyseal and metadiaphyseal regions of the long bones of the lower extremities. A large soft tissue tumor is usually present. Magnetic resonance imaging is the imaging modality of choice to evaluate the extent of the primary lesion, to monitor the response to neoadjuvant chemotherapy and to follow up non-resected Ewing's sarcomas. Bone scintigraphy is necessary to detect skeletal metastasis, and 201thallium scanning has been shown to be sensitive in the monitoring of treatment response. Today, computed tomography is not longer used to image the tumor site; however, spiral CT of the lungs plays a central role as a staging and follow-up tool.