bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of dominance genetic variances for reproductive traits and growth traits of calves in Japanese Black cattle
Authors: ISHIDA Takafumi , MUKAI Fumio
Published: July 2004

The dominance genetic effects for reproductive and calf growth abilities in the practical Japanese Black populations were examined using average information (AI) algorithm restricted maximum likelihood (REML) under animal models. The reproductive traits were observed in Japanese Black cattle maintained at Tottori and Okinawa prefectures, and growth traits of calves were observed in cattle at Okinawa. The average of dominance relationships in Tottori ranged from 0.2 to 0.4%, while the level in Okinawa was lower and sparse compared with Tottori. The proportions of the dominance variances to sum of additive and dominance variances () were all 0.02 for reproductive traits in Tottori. In contrast, the proportion was 0.02–0.64 in Okinawa regardless of the level of dominance relationships. These proportions suggested that the dominance might affect the expression of calving interval, days open and gestation length in Okinawa, where breeding units were spread over many islands. Although the dominance variances could not estimate birthweight, w as 0.34 for calf market weight and 0.27 for average daily gain from birth to calf market in Okinawa. These values also suggested that the dominance might affect the early growth of calves. In the near future, genetic relationships will become more complicated with continuation of the current selection and mating systems. Therefore, genetic evaluation accounting for dominance effects would be necessary for particular traits and populations.
Analysis of mitochondrial DNA protein‐coding region in the Yeso Sika deer (Cervus nippon yesoensis)
Authors: WADA Kenta , YOKOHAMA Michinari
Published: July 2004

In the present study, mitochondrial DNA sequences of the Yeso Sika deer (Cervus nippon yesoensis) were studied. Specifically, protein‐coding genes as mitochondrial NADH dehydrogenase subunits (ND1, ND2, ND3, ND4L, ND4, ND5 and ND6), cytochrome c oxidase subunits (CO I and CO III), ATP synthase subunits (ATPase8 and ATPase6) and cytochrome b. Also, phylogenetic analyses on eight mammalian species were performed, including the Muntjac deer (Muntiacus reevesi). The rate of amino‐acid substitution was lowest (3.74%) between Yeso Sika deer and Muntjac deer, and the values between Yeso Sika deer and other species (sheep, cattle, horse, pig, mouse, human and chimpanzee) were 6.63%, 7.30%, 12.55%, 13.03%, 23.59%, 24.82% and 25.04%, respectively. Among them, the highest value of divergence was recognized in ATPase8, and the second structure of ATPase8 showed a difference between the Yeso Sika deer and Muntjac deer as a result of the substitution of 34His→Tyr and 49Thr→Ile. In addition, we identified a substitution of an amino‐acid sequence (19Thr→Ala) between the Yeso Sika deer and Yakushima Sika deer (C. n. yakushimae). From these results, ATPase8 was also a variable region in Cervidae.
Polymorphism and evolutionary profile of mitochondrial DNA control region inferred from the sequences of Pakistani goats
Authors: SULTANA Saira , MANNEN Hideyuki
Published: July 2004

Complete mitochondrial DNA (mtDNA) control region of 30 Pakistani domestic goats was sequenced to investigate the genetic diversity and organization. Twenty‐two new haplotypes were observed and all were classified into mt‐lineage A. Phylogenetic analysis revealed two distinct clusters in mt‐lineage A, A1 and A2. A 17 bp deletion and a 76 bp insertion were detected in the L‐domain and observed 10 and one animals, respectively, in 232 Pakistani domestic goats. These remarkable deletion/insertion events would be useful to investigate mtDNA diversity within the highly divergent mt‐lineage A. In analysis of the control region feature, the caprine mtDNA was A/T rich as observed for other artiodactyls. Four conserved regions, Block A in the L domain, the C‐domain, Block B and CSB1 in the R domain, were defined as well as in the other species.
Effect of growth hormone on estrogen receptor binding properties in the chick oviduct in vivo
Authors: TAKAHASHI Tetsuya , OGAWA Hiroshi , KAWASHIMA Mitsuo
Published: July 2004

The equilibrium dissociation constant (Kd) and the maximum binding capacity (Bmax) of estrogen receptor in cytosolic and nuclear fractions in oviduct of pullets following various daily injections (1–10 times) of growth hormone (GH: 50 µg/chick) were examined by Scathchard analysis of specific [3H]estradiol‐17β (E2) binding. The Kd values of receptor in both fractions decreased after three times of GH‐injection. In the Bmax values, three times of the injection caused a marked decrease in that value in the cytosolic fraction with a concomitant increase in that in the nuclear fraction, whereas the total Bmax (sum of Bmax in the cytosolic and nuclear fractions) did not change. A similar relationship between the Kd values in the binding of the two fractions was also observed in 4–10 times of GH‐injection. However, in 4–10 times of GH‐injection the Bmax of the both fractions and total Bmax was greater than that in vehicle‐injection (control). When the chicks were injected with 6–10 times of GH‐injection, the weight of oviduct was increased. No change in the plasma concentrations of E2 was found following GH‐ and vehicle‐injections into the chicks. The results suggest that growth hormone stimulates the growth of the chick oviduct by increasing the binding affinity and capacity of estrogen receptor.
Partial characterization of structure and function of a xylanase gene from the rumen hemicellulolytic bacterium Eubacterium ruminantium
Authors: TAGUCHI Hidenori , KOIKE Satoshi , KOBAYASHI Yasuo , CANN Isaac K. O. , KARITA Shuichi
Published: July 2004

A gene encoding for xylanase activity in the rumen hemicellulolytic bacterium Eubacterium ruminantium was cloned into pBR322 in Escherichia coli (E. coli ). The primary clone had a 5.7 kb insert produced by Eco RI partial digestion. Subcloning followed by sequencing allowed for the discovery that this enzyme has a glycosyl‐hydrolase family 10 catalytic domain with a family 9 carbohydrate binding module at C‐terminus and a region partially homologous to a family 22 carbohydrate binding module at N‐terminus. Cloned xylanase is specifically active against xylan and oligoxyloside to produce xylobiose and xylotriose, showing optimal pH and temperature at 7.0 and 50°C, respectively. Molecular size of the xylanase (91 kDa) was confirmed by zymogram analysis of the E. coli clone, which agreed with the predicted size from the DNA sequence. Functions of the two modules at C‐ and N‐termini were evaluated by using xylanase variants with and without the respective module and the C‐terminal module was found to be functional in binding to acid‐swollen cellulose and insoluble oat‐spelt xylan, whereas the N‐terminal module was inactive for binding them.
Diversity of chemical composition, dry matter intake, in vivo digestibility and in situ dry matter degradability of oat hay (Avena sativa)
Authors: MAZUMDER Md. Arifur Rahman , KUMAGAI Hajime , MITANI Katsunosuke
Published: July 2004

Diversity of chemical composition, in vivo digestibility and in situ dry matter degradability of oat hay (Avena sativa) were studied. Oat hay samples obtained from 22 batches imported were analyzed for chemical composition. The result showed a wide range of variations in crude protein (3.9–8.8%, on a dry matter basis), crude fiber (22.1–35.2%), nitrogen free extract (50.0–66.0%), organic cellular contents (23.4–40.0%), organic cell wall (53.1–70.8%), organic a (4.1–9.8%), organic b (49.0–63.8%) fractions and the estimated total digestible nutrients (50.3–63.8%) from the organic components. Of these, four oat hay samples were used for the measurement of dry matter intake, in vivo digestibility and in situ dry matter degradability in sheep. Significant differences were observed for the dry matter intake, in vivo digestibility of dry matter, crude protein, crude fiber and nitrogen free extract, dry matter disappearance at 48 h and effective degradability at k = 0.05 h−1 of the samples (P < 0.05). The results revealed a wide range of diversity of nutritional quality of the imported oat hay that could have an affect on production potential in animals.
Diet supplied with L‐lysine and L‐arginine during chronic stress of high stock density normalizes growth of broilers
Authors: SRINONGKOTE Saksit , SMRIGA Miro , TORIDE Yasuhiko
Published: July 2004

The effects of fortifying a diet with L‐lysine HCl (Lys) and L‐arginine (Arg) in broilers housed under conditions of high stock density, were studied in an experiment that measured bodyweight, feed intake, feed conversion, body temperature, serum protein, immune parameters and neutrophils. A diet fortified with Lys and Arg increased bodyweight gain in broilers housed under high stock density conditions, but not in normally housed controls. The diet fortified with Lys and Arg decreased the feed conversion ratio and abdominal fat, as compared to the effects of a control diet, without regard to housing conditions. No effects of amino acid fortification or stock density on body temperature, serum protein or immune parameters were recorded. The results indicate that an increase in the dietary supply of Lys and Arg is beneficial to broilers during stressful conditions of high stock density, potentially contributing to an enhancement of animal welfare in broiler farms.
Comparative analysis of mechanical stretch‐induced activation activity of back and leg muscle satellite cells in vitro
Authors: TATSUMI Ryuichi , MITSUHASHI Kei , ASHIDA Ken , HARUNO Atsushi , HATTORI Akihito , IKEUCHI Yoshihide , ALLEN Ronald E.
Published: July 2004

It has previously been shown that mechanical stretch induces activation of cultured quiescent satellite cells by rapid release of hepatocyte growth factor (HGF) from its extracellular association with satellite cells and its subsequent presentation to the c‐met receptor. The present study provides evidence that the stretch activation activity varies according to the origin of satellite cells from back and leg skeletal muscles in vitro. Satellite cells were isolated from three muscle groups, back (BK), upper hind limb (UL) and lower hind limb (LL) muscles, of adult male rats and stretch activation activities were compared. In response to stretch, lower hind limb satellite cells showed significantly greater response than upper hind limb and back muscles (LL > UL > BK). Immunoblots of stretched culture media revealed a higher HGF‐releasing capacity of lower hind limb satellite cells than back muscle satellite cells. In addition, lower hind limb satellite cells exhibited a greater activation activity in response to exogenous HGF added to culture media than compared to satellite cells from back and upper hind limb (LL > UL > BK). The increased ability to release HGF and the increased cellular responsiveness might account for higher stretch activation activities of lower hind limb satellite cells. Electrophoretic analysis of myosin heavy chain isoforms verified a higher content of slow muscle fibers in lower limb muscles (LL > UL > BK), suggesting a difference in stretch‐induced activation activity between satellite cells associated with fast and slow muscle fibers.
Myofibrillar proteolysis in chick muscle cell cultures during heat stress
Authors: NAKASHIMA Kazuki , NONAKA Itoko , MASAKI Shigehiko , YAMAZAKI Makoto , ABE Hiroyuki
Published: July 2004

The effect of heat stress on protein oxidation and myofibrillar proteolysis in chick myotubes was investigated. Myotubes were incubated at 37 or 41°C for 6 and 24 h. Protein carbonyl content, as an index of protein oxidation, increased more at 41°C than at 37°C for 6 and 24 h incubations. Nτ‐methylhistidine release as an index of myofibrillar proteolysis also increased more at 41°C than at 37°C for 6 and 24 h incubations. Proteasome activity also increased more under those same conditions. Calpain and cathepsin D but not B + L activities showed a greater increase at 41°C than at 37°C for 24 but not the 6 h incubation. These results indicate that heat stress increases protein oxidation and proteasome activity, resulting in an increase in myofibrillar proteolysis for short‐term incubation and, for long‐term incubation, it increases calpain, proteasome and cathepsin D activities, finally accelerating myofibrillar proteolysis in chick myotubes.
Effects of slaughter age on the levels of free amino acids and dipeptides in fattening cattle
Authors: WATANABE Akira , UEDA Yasuko , HIGUCHI Mikito
Published: July 2004

The effects of slaughter age, breed type and postmortem period were studied on the concentrations of free amino acids (FAA) and dipeptides (carnosine and anserine) in Longissimus dorsi muscle of beef. Slaughter age affected the levels of most FAA and dipeptides, and the concentrations of these compounds were significantly lower at 35 months of age than either 15 or 25 months of age. Slight increases were observed at 25 months compared with 15 months, but the differences were not significant except for a few FAA. These tendencies still remained when the concentrations were recalculated on the basis of protein. A significant breed effect was observed for taurine, carnosine and anserine. Almost all FAA were significantly increased during postmortem conditioning, but the level of each FAA fluctuated, and the fluctuations could not be explained statistically by slaughter age or breed differences.
Questionnaire‐based study on consumer requirements for beef quality in Japan
Authors: SASAKI Keisuke , MITSUMOTO Mitsuru
Published: July 2004

A questionnaire study examining Japanese consumers’ requirements for beef quality was carried out in April 2002 in Tsukuba, Ibaraki, Japan. Answers from 532 participants were used for the statistical analysis. Twenty questions about sensory properties, appearance, safety and freshness, production area, price, and other properties were prepared. The answers were applied to principal component analysis. Five principal components were obtained and defined, and the principle component scores were used to classify participants. The panels were classified into four groups profiled as ‘specific quality orientated’, ‘Wagyu (Japanese beef) orientated’, ‘safety and freshness orientated’ and ‘overall high quality orientated’. In addition, gender and age characteristics were different among the groups. Sensory properties did not affect the classification of respondents.
Development of immune assay system for both CpG and non‐CpG DNA from lactic acid bacteria using a transfectant of swine Toll‐like receptor 9
Authors: SHIMOSATO Takeshi , KITAZAWA Haruki , TOHNO Masanori , KATOH Shinichiro , KAWAI Yasushi , SAITO Tadao
Published: July 2004

Bacterial DNA is expected to be a potent immune stimulating agent to Toll‐like receptor (TLR) 9 expressed cells such as macrophages, monocytes, B lymphocytes, NK cells and dendritic cells. In the present study, we constructed a transfectant of swine TLR9 with mammalian cells. We demonstrated that the transfectant, recognizing both CpG and non‐CpG oligonucleotides from lactic acid bacteria, induced NF‐κB activation by gene reporter assay. These findings indicate that the swine TLR9 transfectant will be highly useful for the screening of immunostimulatory DNA from lactic acid bacteria.
Continuous Tracking of Heliostats
Authors: Kribus Abraham , Vishnevetsky Irina , Meri Moshe , Yogev Amnon , Sytnik Andrei
Published: July 2004

Tracking motions in current heliostats are usually performed in discrete steps, even though the motion of the sun is continuous. Aiming errors due to the discrete steps are often about 1 mrad or more. A significant reduction of tracking error by smooth continuous tracking is presented. The implementation uses an electronic speed control unit to modify the rotational speed of the two AC motors on an existing heliostat. The continuous tracking system was implemented and successfully operated at the Weizmann Institute heliostat field. Measurements of heliostat motion show that aiming error due to tracking intervals was practically eliminated. A comparison of heliostat motions and flux on the target in step-tracking and continuous tracking modes is reported.
A Liquid Desiccant System for Solar Cooling and Dehumidification
Authors: Gommed K. , Grossman G.
Published: July 2004

The growing demand for air conditioning, particularly in hot and humid climates has caused a significant increase in demand for energy resources. A promising solar technology with potential to alleviate the problem is an open absorption system, where humidity is absorbed directly from the air to be treated by direct contact with the absorbent. The absorbent is then regenerated, again in direct contact with an external air stream, at relatively low temperatures of the heat source. The paper describes a study of a liquid desiccant cooling system designed to air-condition a group of offices on the top floor of a building in the Mediterranean city of Haifa, Israel. The system is capable of using as its source of power low-grade solar heat, of the type obtainable from low-cost flat plate collectors, and has a potential to provide both cooling and dehumidification in variable ratios, as required by the load. Several cycle variations have been considered, corresponding to different design options. A parametric study shows that entrance conditions of the ambient air significantly affect the heat and mass transfer occurring during the dehumidification process. The temperatures and flow rates of the heating and cooling water and the flow rates of solution through the dehumidifier and regenerator affect the humidity of the supply air delivered to the conditioned space, and show an optimum in certain cases.
Chemical Kinetics Simulation of High Temperature Hydrocarbons Reforming in a Solar Reactor
Authors: Rubin Rachamim , Karni Jacob , Yeheskel Jacob
Published: July 2004

This study is aimed at developing a simulation model of a solar volumetric reactor for hydrocarbon reforming, operating at high temperature and pressure. It will then be used to optimize the reactor design and analyze its performance. The model development utilizes previous and on-going experimental work on volumetric receiver and catalyst development. The reaction’s kinetics are computed, using the CHEMKIN II simulation package. The chemical kinetic modeling of the relevant C-H-O system is based on: (i) Definition of the relevant computation domain and parameters: temperature, pressure, reactant compositions, residence time, and catalyst load, (ii) Utilizing laboratory measurements at 700–1400 K and 1–4 bar. to quantify the kinetic parameters for both, H2O, and CO2 reforming of CH4 and for the Reverse Water Shift reaction. Calculated and measured data are compared for three representative cases, showing a good agreement. The results indicate that the Arrhenius method can be a viable and practical way to predict the behavior of steam and CO2 reforming over a range of temperatures and pressures. Furthermore, it is shown that the present approach can provide a method for estimating the desirable dimensions of the reactor for reforming of CH4. Additional, on-going computational and experimental work, which would provide a more accurate simulation, can easily be implemented using the present numerical model.
A Study on Simulations of the Power Output and Practical Models for Building Integrated Photovoltaic Systems
Authors: Lu Lin , Yang H. X.
Published: July 2004

With the rapid increase in Building Integrated Photovoltaic (BIPV) systems and the popularity of photovoltaic (PV) applications, a simple but accurate model to calculate the power output of PV modules is crucial for evaluating systems. In addition, in the analysis of energy payback, two factors, the power output (maximum power output) model of PV modules and the representative local weather data, affect calculations of the energy savings and the payback time of BIPV systems. Most studies take the efficiency of PV modules as constant when calculating the energy payback time of PV systems, and ignore the influence of solar radiation and temperature on the results of the calculation. This study tries to develop one simple, practical, yet more accurate model for describing the characteristics of the power output of PV modules. It develops a model for describing the I-V characteristics of PV modules according to the equivalent circuits of solar cells, by which an accurate but complicated model of the maximum power output (MPO) can be achieved. Taking this MPO model as a benchmark, two other application models from other studies are evaluated and examined. One simplified application model for describing the maximum power output of PV modules is then derived from the results of the simulation. Once the solar radiation on PV panels and the ambient temperature are known, the power output of BIPV systems or PV systems can be calculated accurately and easily.
Effect of Voltage Level on Power System Design for Solar Electric Propulsion Missions
Authors: Kerslake Thomas W.
Published: July 2004

This paper presents study results quantifying the benefits of higher voltage, electric power system designs for a typical solar electric propulsion spacecraft Earth orbiting mission. A conceptual power system architecture was defined and design points were generated for several system voltages using state-of-the-art or advanced technologies. A 300-V “direct-drive” architecture was also analyzed to assess the benefits of directly powering the electric thruster from the photovoltaic array without up-conversion. Computational models were exercised to predict the performance and size power system components to meet spacecraft mission requirements. Pertinent space environments were calculated for the mission trajectory and an electron current collection model was developed to estimate photovoltaic array losses due to natural and induced plasma environments. The secondary benefits of power system mass savings for spacecraft propulsion and attitude control systems were also quantified. Results indicate that considerable spacecraft wet mass savings were achieved by the 300-V and 300-V direct-drive architectures.
Standard Skies Classification Using Common Climatic Parameters
Authors: Li Danny H. W. , Lau Chris C. S. , Lam Joseph C.
Published: July 2004

A good understanding of the sky luminance distribution is essential for efficient daylighting designs and developments. Sky luminance patterns are always modeled under various sky conditions using climatic parameters as weighting factors to indicate the degree of sky clearness. This paper presents the work on the identification of sky luminance patterns using three common climatic elements, namely cloud cover (CLD), sunshine hour (SH) and clearness index Kt. Three sky types representing overcast, partly cloudy and clear were selected from the Kittler et al. 15 standard skies. It has been shown that sky conditions classified by individual sky indicators produced acceptable agreements with the measured data. In general, CLD shows the best results, followed by Kt, then SH. Better results in terms of the frequency of occurrence and root mean square errors can be found when CLD and SH are jointly utilised to describe the sky conditions.
NASA Climatological Data for Renewable Energy Assessment
Authors: Chandler William S. , Whitlock Charles H. , Stackhouse, Paul W.
Published: July 2004

This article presents the latest parameters and delivery methods that provide global solar energy and meteorological resources on the Internet. Over the past several years the number of parameters in the Surface meteorology and Solar Energy Data Set has tripled. The newest parameters include solar geometry, a suite of wind speed and wind direction data, diffuse, direct normal and tilted surface solar irradiance. Requests by users and recommendations by the renewable energy industry have prompted the growth.
Characteristic Heat Removal Efficiency for Thermosyphon Solar Water Heaters During the System Application Phase
Authors: Chang J. M.
Published: July 2004

The overall performance rating of a thermosyphon solar water heater should take into consideration its heat removal efficiency during the system application phase. This study employs a precise on-line operation to first identify physical heat removal patterns of a thermosyphon solar water heater, and then develops an empirical model for deriving its characteristic heat removal efficiency. This empirical model is in the form of a logarithmic curve, and has a high data correlation coefficient of 0.889 to 0.967. Based upon the empirical model, this study defines a characteristic heat removal efficiency parameter for thermosyphon solar water heaters. Finally, this study establishes a storage tank design method which enables the characteristic heat removal efficiency of the complete system to be optimized.
Solar Gasification of Biomass: A Molten Salt Pyrolysis Study
Authors: Adinberg Roman , Epstein Michael , Karni Jacob
Published: July 2004

A novel solar process and reactor for thermochemical conversion of biomass to synthesis gas is described. The concept is based on dispersion of biomass particles in a molten inorganic salt medium and, simultaneously, absorbing, storing and transferring solar energy needed to perform pyrolysis reactions in the high-temperature liquid phase. A lab-scale reactor filled with carbonates of potassium and sodium was set up to study the kinetics of fast pyrolysis and the characteristics of transient heat transfer for cellulose particles (few millimeters size) introduced into the molten salt medium. The operating conditions were reaction temperatures of 1073–1188 K and a particle peak-heating rate of 100 K/sec. The assessments performed for a commercial-scale solar reactor demonstrate that pyrolysis of biomass particles dispersed in a molten salt phase could be a feasible option for the continuous, round-the-clock production of syngas, using solar energy only.
What are the Required Conditions for Heavy Structure Buildings to be Thermally Effective in a Hot Humid Climate?
Authors: Capeluto Isaac G. , Yezioro Abraham , Shaviv Edna
Published: July 2004

We calculate the influence of thermal mass and night ventilation on the reduction of the maximum indoor temperature in summer in residential buildings without using air-conditioning. The results are given for different locations in the hot-humid Mediterranean climate of Israel. We found that the maximum obtained indoor temperature reduction depends linearly on the temperature difference between day and night at the site. The results obtained show that one can predict the indoor temperature decrease, due to the thermal mass and night ventilation, from the simple and available data of the long term average temperature swing of the site, which is a common available data. The conclusion is that in the hot-humid climate of the Mediterranean coast, high thermal mass with night ventilation is effective for residential buildings with no air-conditioning provided the temperature swing is above 5°C, which is in general the case in this climate.
A High Surface Area Organic Solar Cell Prepared by Electrochemical Deposition
Authors: Diamant Yishay , Zaban Arie
Published: July 2004

A new design of a high surface area solid state organic solar cell is presented. The solid cell consists of a PPEI/TiOPc junction deposited inside a nanoporous TiO2 electrode, utilizing its high surface area (where PPEI=Perylenebisphenethylimide and TiOPc=Titanylphthalocyanine). The deposition of the organic semiconductors was performed by a new electrochemical deposition method, which is based on a simultaneous ionic dissolution and electrochemical re-neutralization of the organic materials. Although the overall conversion efficiency of the solid state cell is low, the analogous wet cell, TiO2/PPEI/TiOPc electrode in contact with redox electrolyte mediator, shows a photoresponse throughout the PPEI spectrum. The efficiencies of the various processes of photocurrent generation were examined and the results suggest that all steps are efficient except the electron transfer from the PPEI to the TiO2. This limitation is attributed to a thin dipole layer formed during the electrodeposition process, which alters the relative energetics at the PPEI/TiO2 interface.
Optimal Solar Field Design of Stationary Collectors
Authors: Weinstock Dan , Appelbaum Joseph
Published: July 2004

The optimal design of stationary photovoltaic and thermal collectors in a solar field, taking into account shading and masking effects, may be based on several criteria: maximum incident energy on collector plane from a given field, minimum field area for given incident energy, minimum cost per unit energy, minimum plant cost, maximum energy per unit collector area or other objectives. These design problems may be formulated as optimization problems with objective functions and sets of constraints (equality and inequality) for which mathematical optimization techniques may be applied. This article deals with obtaining the field design parameters (optimal number of rows, distance between collector rows, collector height and collector inclination angle) that produce maximum annual energy from a given field. A second problem is determination of the minimum field area (length and width) and field design parameters that produce a given required annual energy. The third problem is determination of the optimal field design parameters for obtaining maximum energy per unit collector area from a given field. The results of these optimal designs are compared to a recommended approach of the Israeli Institute of Standards (IIS) in which the solar field design result in negligible shading. An increase in energy of about 20% for a fixed field area and a decrease in field area of about 15% for a given annual incident energy, respectively, may be obtained using the approach formulated in the present article compared to the IIS approach.
The Negev Radiation Survey
Authors: Faiman David , Feuermann Daniel , Ibbetson Peter , Medwed Bryan , Zemel Amos , Ianetz Amiran , Liubansky Vera , Setter Ilan , Suraqui Samuel
Published: July 2004

We present a summary of the principal findings in an ongoing, multiyear, survey of the solar radiation resource and associated meteorological parameters in Israel’s Negev Desert. The summary addresses calibration and monitoring issues, the format in which the annual results are published, availability of the data, and some of the more interesting results observed to date. In particular, we quantify the large variability observed in the direct beam radiation across neighboring sites. The year-to-year variation in this radiation component is also considerable. The variation in the global horizontal radiation is much smaller. Two practical examples are given of uses to which the Negev Radiation Survey has been put: Site selection for a proposed 500 MW solar-thermal power plant; and an estimation of the potential photovoltaic value of rooftops in the major cities.
Experimentally Determined Optical Properties of a Polydisperse Carbon Black Cloud for a Solar Particle Receiver
Authors: Bertocchi Rudi , Kribus Abraham , Karni Jacob
Published: July 2004

Measured physical and optical properties of a stable polydisperse carbon black particle cloud at 532 nm and 1064 nm are reported. The particle cloud consisted of 99.7% spheroid primary particles (45–570 nm diameter) and 0.3% large irregularly shaped agglomerates (1.2–7.25 μm equivalent diameter). Although the numerical fraction of the agglomerates was only 0.2%, they contributed 60% to the cloud’s scattering cross section. The extinction coefficient, scattering coefficient and the scattering phase function were measured for both parallel and perpendicular polarized radiation at linear extinction coefficients ranging from 0.6 to 4.1 m−1. The cloud exhibited strong forward scattering, with 62% of all scattered energy in a forward lobe of 15° at 532 nm and 48% at 1064 nm. The scattering albedo was measured to 35% at 532 nm and 47% at 1064 nm. The dimensionless extinction coefficient was measured to 8.25 at 532 nm. The experimental data was compared to standard Mie theory by integrating the weighed contribution based on particle size, including agglomerates, according to the detailed measured population distribution. Neglecting the contribution of the agglomerates to the cloud’s optical properties was shown to introduce discrepancies between Mie theory and measured results. The results indicate that the-Mie theory can be used for estimating the optical properties of a partially agglomerated carbon black particle cloud for simulation of a solar particle receiver.
Determining the Optical Properties of PETAL, the 400m2 Parabolic Dish at Sede Boqer
Authors: Biryukov S.
Published: July 2004

PETAL (Parabolic Energy Transformation and Astrophysics Laboratory) is a large multipurpose dish-shaped concentrator, located at Sede Boqer. Its 2-axis tracking paraboloidal surface, with aperture area in excess of 400m2, is constructed from 216 adjustable mirror panels. The very large aperture and high concentration ratio of PETAL render the direct characterization of its optical performance a nontrivial task. We have applied a variety of methods in order to assess PETAL’s optical quality. These include imaging the full moon and Jupiter at night, and analysis of the 3-D caustic image produced by the scattering of focused sunlight off particles in the air. The main results of these studies, together with the preliminary results of measurements on 36 individual panels, are presented here. Among the three measurements that look at objects of the same angular size (i.e. the sun and moon), the average image size (i.e. radius of circle containing 90% of the intensity) is 0.247±0.012m, demonstrating a 5% spread about the mean for three different methods. This result is in agreement with 0.22 m for the Jupiter image. Successful application of these methods for characterization of PETAL proves their applicability to more commonly used solar dishes of smaller sizes but with similar or better concentration ratios.
Solar Energy Research and Development Achievements in Israel and Their Practical Significance
Authors: Einav Amnon
Published: July 2004

This paper reviews the pioneering efforts done in Israel over the last 50 years to explore different directions of developing the solar energy resource as an alternative energy supply. An early start included the improvement of solar collectors for heating water for domestic uses. This was followed by low-temperature Organic Rankine Cycle turbines to supply electricity for remote locations, and then the development and commercialization of the SEGS Solar Thermal power plants. Current research directions are described, including high temperature Solar Tower power systems, production of “solar fuels” at high temperature to enable storage and transportation of solar energy, photovoltaic materials and photovoltaic systems development, solar absorption cooling, and the bold idea of large “Energy Towers” to produce electric energy from cooling of hot dry desert air. The paper concludes that additional efforts in Israel and abroad to continue developing and deploying of solar energy systems, having benevolent influence on the environment, should continue.
On the Design and Analysis of a Pyrheliometer Comprising a Convex Lens
Authors: Dayan A. , Olbinsky A. , Mittelman G.
Published: July 2004

A novel pyrheliometer, based on a solar irradiance concentration method, has been designed, constructed and calibrated. An analytical model of the instrument was developed and incorporated for the design and investigation of the instrument performance. The apparatus contains a small receiver that intercepts and absorbs the solar beam irradiation near the focus of a convex lens, by which the flux is concentrated. The irradiated receiver area is isothermal owing to its small dimensions and high thermal conductivity. Therefore, a single thermo-couple is sufficient to measure the temperature difference between the receiver irradiated area and its surroundings. The solar irradiative flux is evaluated by substituting the recorded temperature difference into, either, a linear experimental calibration chart or into a linear characteristic formula that was derived analytically. The instrument calibration was performed at the Israeli Institute of Standards, using an EPLAB normal incidence pyrheliometer as a reference. The new instrument is inexpensive, simple and portable. Its accuracy is suitable for routine field measurements of direct solar beam irradiation. The analytical model is typical to many solar radiation collection problems and could be considered as useful analytical tool, beyond the specific purpose for which it was developed.
Modification of Gas Turbines and Operation with Solar Produced Syngas
Authors: Sugarmen C. , Rotstein A. , Fisher U. , Sinai J.
Published: July 2004

Solar energy can be utilized to drive chemical processes to produce syngas, a hydrogen rich fuel that can be used for power generation. ORMAT took part in the Solasys project in which syngas was produced by a reforming process driven by solar energy. The solar energy was concentrated in a volumetric receiver. ORMAT presented two modes of operation for introducing syngas to a gas turbine. One mode of “syngas only” and the second for utilization of mixtures of LPG and syngas. Modification of a gas turbine to be fueled only with syngas, incorporated modifications in the combustion chamber, fuel system and control system. The gas turbine which operated on mixtures of LPG and syngas was not modified but an external fuel mixing system was added ahead of its gas line. It operated smoothly with the mixed fuel, with minimum drop in performance up to about 40% syngas in the mixture, contributing approximately 20% of solar energy to the electric power production with up to 80% syngas mass fraction in the fuel.
Gas Turbine “Solarization”-Modifications for Solar/Fuel Hybrid Operation
Authors: Fisher Uri , Sugarmen Chemi , Ring Arik , Sinai Joseph
Published: July 2004

Achieving solar produced electricity at a reasonable price with large utility-size units is a worldwide goal. This can be achieved by high efficiency systems and hardware cost reduction. The ORMAT Brayton cycle solar hybrid gas turbine is a step in this direction. ORMAT took part in several solar projects in which it contributed to the “solarization” of the complete power block. This paper describes the main tasks involved in solarization, and includes experimental test results where helicopter turboshaft gas turbines were used. The paper reviews several solar projects and mainly the SOLGATE project during the years 2001–2003. During 2002–2003 the turbine was operated in Spain, combined with three volumetric receivers. The initial goal of achieving 800°C at the receiver outlet was achieved and is reported on below. The successful tests have encouraged the continuation of work using gas turbines of 10 MW and above, which has already commenced.
The Sodium-Driven Flagellar Motor Controls Exopolysaccharide Expression in
Vibrio cholerae
Authors: Lauriano Crystal M. , Ghosh Chandradipa , Correa Nidia E. , Klose Karl E.
Published: July 2004

Vibrio cholerae
causes the life-threatening diarrheal disease cholera. This organism persists in aquatic environments in areas of endemicity, and it is believed that the ability of the bacteria to form biofilms in the environment contributes to their persistence. Expression of an exopolysaccharide (EPS), encoded by two
vps
gene clusters, is essential for biofilm formation and causes a rugose colonial phenotype. We previously reported that the lack of a flagellum induces
V. cholerae
EPS expression. To uncover the signaling pathway that links the lack of a flagellum to EPS expression, we introduced into a rugose
flaA
strain second-site mutations that would cause reversion back to the smooth phenotype. Interestingly, mutation of the genes encoding the sodium-driven motor (
mot
) in a nonflagellated strain reduces EPS expression, biofilm formation, and
vps
gene transcription, as does the addition of phenamil, which specifically inhibits the sodium-driven motor. Mutation of
vpsR
, which encodes a response regulator, also reduces EPS expression, biofilm formation, and
vps
gene transcription in nonflagellated cells. Complementation of a
vpsR
strain with a constitutive
vpsR
allele likely to mimic the phosphorylated state (D59E) restores EPS expression and biofilm formation, while complementation with an allele predicted to remain unphosphorylated (D59A) does not. Our results demonstrate the involvement of the sodium-driven motor and suggest the involvement of phospho-VpsR in the signaling cascade that induces EPS expression. A nonflagellated strain expressing EPS is defective for intestinal colonization in the suckling mouse model of cholera and expresses reduced amounts of cholera toxin and toxin-coregulated pili in vitro. Wild-type levels of virulence factor expression and colonization could be restored by a second mutation within the
vps
gene cluster that eliminated EPS biosynthesis. These results demonstrate a complex relationship between the flagellum-dependent EPS signaling cascade and virulence.
Three Different Systems Participate in
l
-Cystine Uptake in
Bacillus subtilis
Authors: Burguière Pierre , Auger Sandrine , Hullo Marie-Françoise , Danchin Antoine , Martin-Verstraete Isabelle
Published: July 2004

The symporter YhcL and two ATP binding cassette transporters, YtmJKLMN and YckKJI, were shown to mediate
l
-cystine uptake in
Bacillus subtilis
. A triple Δ
yhcL
Δ
ytmJKLMN
Δ
yckK
mutant was unable to grow in the presence of
l
-cystine and to take up
l
-cystine. We propose that
yhcL
,
ytmJKLMN
, and
yckKJI
should be renamed
tcyP
,
tcyJKLMN
, and
tcyABC
, respectively. The
l
-cystine uptake by YhcL (

K
m

= 0.6 μM) was strongly inhibited by seleno-
dl
-cystine, while the transport due to the YtmJKLMN system (

K
m

= 2.5 μM) also drastically decreased in the presence of
dl
-cystathionine,
l
-djenkolic acid, or
S
-methyl-
l
-cysteine. Accordingly, a Δ
ytmJKLMN
mutant did not grow in the presence of 100 μM
dl
-cystathionine, 100 μM
l
-djenkolic acid, or 100 μM
S
-methyl-
l
-cysteine. The expression of the
ytmI
operon and the
yhcL
gene was regulated in response to sulfur availability, while the level of expression of the
yckK
gene remained low under all the conditions tested.
Molecular Cloning and Characterization of
Bifidobacterium bifidum
1,2-α-
l
-Fucosidase (AfcA), a Novel Inverting Glycosidase (Glycoside Hydrolase Family 95)
Authors: Katayama Takane , Sakuma Akiko , Kimura Takatoshi , Makimura Yutaka , Hiratake Jun , Sakata Kanzo , Yamanoi Takashi , Kumagai Hidehiko , Yamamoto Kenji
Published: July 2004

A genomic library of
Bifidobacterium bifidum
constructed in
Escherichia coli
was screened for the ability to hydrolyze the α-(1→2) linkage of 2′-fucosyllactose, and a gene encoding 1,2-α-
l
-fucosidase (AfcA) was isolated. The
afcA
gene was found to comprise 1,959 amino acid residues with a predicted molecular mass of 205 kDa and containing a signal peptide and a membrane anchor at the N and C termini, respectively. A domain responsible for fucosidase activity (the Fuc domain; amino acid residues 577 to 1474) was localized by deletion analysis and then purified as a hexahistidine-tagged protein. The recombinant Fuc domain specifically hydrolyzed the terminal α-(1→2)-fucosidic linkages of various oligosaccharides and a sugar chain of a glycoprotein. The stereochemical course of the hydrolysis of 2′-fucosyllactose was determined to be inversion by using
1
H nuclear magnetic resonance. The primary structure of the Fuc domain exhibited no similarity to those of any glycoside hydrolases (GHs) but showed high similarity to those of several hypothetical proteins in a database. Thus, it was revealed that the AfcA protein constitutes a novel inverting GH family (GH family 95).
A Novel
p
-Nitrophenol Degradation Gene Cluster from a Gram-Positive Bacterium,
Rhodococcus opacus
SAO101
Authors: Kitagawa Wataru , Kimura Nobutada , Kamagata Yoichi
Published: July 2004

p
-Nitrophenol (4-NP) is recognized as an environmental contaminant; it is used primarily for manufacturing medicines and pesticides. To date, several 4-NP-degrading bacteria have been isolated; however, the genetic information remains very limited. In this study, a novel 4-NP degradation gene cluster from a gram-positive bacterium,
Rhodococcus opacus
SAO101, was identified and characterized. The deduced amino acid sequences of
npcB
,
npcA
, and
npcC
showed identity with phenol 2-hydroxylase component B (reductase, PheA2) of
Geobacillus thermoglucosidasius
A7 (32%), with 2,4,6-trichlorophenol monooxygenase (TcpA) of
Ralstonia eutropha
JMP134 (44%), and with hydroxyquinol 1,2-dioxygenase (ORF2) of
Arthrobacter
sp. strain BA-5-17 (76%), respectively. The
npcB
,
npcA
, and
npcC
genes were cloned into pET-17b to construct the respective expression vectors pETnpcB, pETnpcA, and pETnpcC. Conversion of 4-NP was observed when a mixture of crude cell extracts of
Escherichia coli
containing pETnpcB and pETnpcA was used in the experiment. The mixture converted 4-NP to hydroxyquinol and also converted 4-nitrocatechol (4-NCA) to hydroxyquinol. Furthermore, the crude cell extract of
E. coli
containing pETnpcC converted hydroxyquinol to maleylacetate. These results suggested that
npcB
and
npcA
encode the two-component 4-NP/4-NCA monooxygenase and that
npcC
encodes hydroxyquinol 1,2-dioxygenase. The
npcA
and
npcC
mutant strains, SDA1 and SDC1, completely lost the ability to grow on 4-NP as the sole carbon source. These results clearly indicated that the cloned
npc
genes play an essential role in 4-NP mineralization in
R. opacus
SAO101.
Ribosomal Protein S1 Specifically Binds to the 5′ Untranslated Region of the
Pseudomonas aeruginosa
Stationary-Phase Sigma Factor
rpoS
mRNA in the Logarithmic Phase of Growth
Authors: Ševo Milica , Buratti Emanuele , Venturi Vittorio
Published: July 2004

The
rpoS
gene encodes the stationary-phase sigma factor (RpoS or σ
s
), which was identified in several gram-negative bacteria as a central regulator controlling the expression of genes involved in cell survival in response to cessation of growth (stationary phase) and providing cross-protection against various stresses. In
Pseudomonas aeruginosa
, the levels of σ
s
increase dramatically at the onset of the stationary phase and are regulated at the transcriptional and posttranscriptional levels. The
P. aeruginosa rpoS
gene is transcribed as a monocistronic
rpoS
mRNA transcript comprised of an unusually long 373-bp 5′ untranslated region (5′ UTR). In this study, the 5′ UTR and total protein extracts from
P. aeruginosa
logarithmic and stationary phases of growth were used in order to investigate the protein-RNA interactions that may modulate the translational process. It was observed that a 69-kDa protein, which corresponded to ribosomal protein S1, preferentially binds the 5′ UTR of the
rpoS
mRNA in the logarithmic phase and not in the stationary phase. This is the first report of a protein-
rpoS
mRNA 5′ UTR interaction in
P. aeruginosa
, and the possible involvement of protein S1 in translation regulation of
rpoS
is discussed.