Solar-powered air conditioner

We have successfully developed and industrialized a solar-powered air conditioner that operates through a combination of photovoltaic (PV) arrays and commercial power supplies. In order to achieve the most efficient operation possible from a one-horsepower inverter-type household air conditioner, we selected a PV array output of 540 W under standard test conditions, based on single-day power use patterns for air conditioners as well as on solar cell output patterns. When using a 540-W PV array, we have shown that the system can supply at least 90% of the power consumed by an air conditioner during peak power periods in summer. We have confirmed that on average the power generated by the PV array can satisfy at least 50% of the power consumed by an air conditioner in summer. We also confirmed that the system functions according to system design specifications. There is little doubt that the introduction and widespread use of this system will play an important role in reducing peak power energy requirements in summer.     

Optimum design of integrated tandem-type a-Si solar cell submodule

A new optimum design, in which the actual daily spectral data under outdoor conditions over a year were considered, was developed for the integrated tandem-type a-Si solar cell submodule with a structure of glass/TCO/a-Si: H(pinpin)/metal. It was found by this design that the optimum cell number connected in series, at which maximum total annual output power was obtained, was small compared with that obtained by the conventional optimum design under standard conditions (AM1.5, 100 mW cm⁻²). It was also found that when light-induced degradation was considered, the thickness of the i-layer for the second pin cell was thinner than that by the conventional optimum design.     

Characteristics of a-Si solar cells prepared by the super chamber at a high substrate temperature

A new approach to high-performance a-Si solar cells was studied. a-Si films prepared at a high substrate temperature (> 250°C) have a higher absorption coefficient and a low Si H₂ bond density. the effect of deposition temperature on the open-circuit voltage (V_oc) has been investigated systematically for glass/SnO2 Ipin/metal and glass/metal/nip/indium tin oxide (ITO) structure a-Si solar cells. The V_oc is found to depend strongly on the thermal history of the p/i interface. A short-circuit current of 19.5 mA/cm⁻⁻² was achieved for an a-Si solar cell using an a-Si i-layer with a thickness of 4000 Å, which was prepared at a substrate temperature of 270°C.     

Characterization on the Conformation of Glucoamylase from Rhizopus niveus and Rhizopus delemar

Using the pH-jump (neutral to above 11) for Tyr-OH ionization as a probe, two glucoamylases from Rhizopus niveus and Rhizopus delemar were found to be caused the change in conformation, which is in a kinetically single step. The pH titration at pHs below 12 was carried out on a multidimensional correlation spectrophotometer. Correlations among the spectrophotometric properties: fluorescence, absorption and circular dichroism are almost identical for the two enzymes. These results suggest that conformational characteristics of the niveus enzyme is almost the same as that of the delemar one.     

Glucose Production from Maltohexaose as a Substrate by the Bacterial Alpha-amylase-catalyzed Reaction. Its Time Courses Obtained by a Theoretical and an Experimental Approaches

Based on the subsite structure of an α-amylase from Bacillus subtilis, production of glucose from a substrate maltohexaose in the amylase-catalyzed reaction was theoretically predicted as a function of time. The theoretical time course was found consistent with the experimental results, which were obtained by the determination of a product glucose with a commercial assay-kit. Hence, glucose, product from a substrate maltohexaose, will be a useful probe for the amylase-catalyzed reaction.     

Effects of fatty acid and emulsifier on the complex formation and in vitro digestibility of gelatinized potato starch

The effects of fatty acid, monoacylglycerol, and polyglycerol fatty acid ester with varying chain length in their acyl chains on the extent of complex formation (complex index) and in vitro enzymatic digestibility of gelatinized potato starch were investigated. The complex index increased with increase in the concentration of the ligands (fatty acid, monoacylglycerol, and polyglycerol fatty acid ester), with the plateau in the complex index value depending on the type of ligands. In comparison of complex index among fatty acid-samples, the complex index maximum increased as the chain length increased up to octanoic acid and then decreased. In comparison of complex index among fatty acid-, monoacylglycerol-, and polyglycerol fatty acid ester-samples at each acyl chain, the complex index maximum followed the order polyglycerol fatty acid ester > monoacylglycerol > fatty acid. Fatty acid, monoacylglycerol, and polyglycerol fatty acid ester with long acyl chains greatly reduced the enzymatic hydrolysis of starch. Polyglycerol fatty acid ester with palmitic acid chains was the strongest inhibitor of starch hydrolysis, suggesting that further complex formation may occur during the hydrolysis of gelatinized starch (enzyme-annealing).     

An Enzymatic Assay Method for Bacterial Alpha-amylase Using a Glucose Determination-kit and Maltohexaose as the Substrate

Using maltohexaose G₆ as a substrate, a convenient analytical method for amylase-catalyzed hydrolytic reaction was developed by application of an enzymatic assay-kit (glucose oxidase-peroxidase) to measurement of glucose, produced on the reaction: G₆→G₅ + G. The initial velocity was confirmed to be proportional to the initial concentration of amylase, examined, ∼ 100 μm. The new method was found in a good correlation with the Nelson and Somogyi method. Rate assay was also examined: The initial velocity is proportional to the enzyme concentration, ∼ 30 μm. Hence, this enzymatic assay method is recognized to be convenient and useful for the measurement of α-amylase.     

Inhibition in a microgravity environment of the recovery of Escherichia coli cells damaged by heavy ion beams during the NASDA ISS phase I program of NASA Shuttle/Mir mission no. 6

OBJECTIVE: To explore whether there are different disease patterns of rheumatoid arthritis (RA) in women and men. METHODS: We studied 55 male case patients and 110 female control patients who developed RA between 1970 and 1985 and who resided and received medical care in Olmsted County, Minnesota, for at least 10 years after the diagnosis of RA. Case and control patients were matched for the date of first diagnosis. The pattern and extent of joint involvement, the frequency of joint surgeries, and the presence and type of extraarticular manifestations were determined by retrospective chart review. RESULTS: Incidence rates in women were variable and age dependent, whereas the risk in men older than 36 years was constant over their lifetime. Erosive disease was more frequent in men than in women (72% versus 55%, respectively; P < 0.05) and tended to occur earlier (47% versus 31% for erosive disease within the first 4 years of RA). Although male sex was correlated with a higher risk of bony erosions and an accelerated course of RA, structural consequences of joint destruction were more pronounced in women. Joint surgery was performed more frequently in women (50%) than in men (27%) (P = 0.01). In particular, the frequencies of arthroplasties and arthrodeses of hand and foot joints were different (34 procedures in women versus 1 procedure in men; P < 0.001). Sex influenced the risk as well as the pattern of organ involvement in RA. Nodules and rheumatoid lung disease were typical manifestations in men (P = 0.001 and P < 0.001, respectively), whereas women typically developed sicca syndrome (P = 0.05). Despite differences in disease aggressiveness and disease pattern, there was little difference in the medical therapy in the men compared with the women. CONCLUSION: RA is a heterogeneous disease with variations in phenotype. Sex-associated factors influence disease severity as well as disease pattern. Because sex-related effects influence treatment goals, treatment responses, and side effects, they should be considered in clinical study design and analysis as well as in the treatment decisions for individual patients with RA.     

User's requests (from a practitioner's perspective)

As a practitioner, I have to rely on outside clinical laboratories and affiliated hospitals to perform laboratory tests. In this abstract, I describe specific problems I have encountered with third-party laboratories, and propose solutions for these problems to optimize use of laboratory tests. BLOOD TESTS: The most frequent problem in ordering blood tests is the lack of detailed information regarding sampling conditions. I often have to call laboratories to check whether the sample should be serum or plasma, what volume is needed, whether the sample should be cooled, etc. I propose that clinical laboratories should provide practitioners' manuals that describe specific sampling information. ULTRASONOGRAPHY: Most laboratories do not keep the data from ultrasonographic tests. The lack of these is most problematic when test results are interpreted differently by laboratories and by practitioners. Retaining the data would also help private laboratories improve the quality of the test by enabling them to compare their interpretations with others'. ANNUAL MEDICAL SCREENING: Even if an abnormal finding is detected at medical screening clinics, the final diagnosis is usually not sent back to the screening facilities. This is highly recommended to establish an official system that mediates the feedback to screening centers. MRI: Due to miscommunication between practitioners and radiologists, the test is sometimes performed inappropriately. A thorough consultation should occur before the test to clarify specific goals for each patient. PATHOLOGICAL TESTS: Interpretation of results is often inconsistent among laboratories. Independent clinical laboratories tend to report results without indicating sample problems, while pathology departments at affiliated hospitals tend to emphasize sample problems instead of diagnosis or suggesting ways to improve sample quality. Mutual communication among laboratories would help standardize the quality of pathological tests.