bluuebunny/crossref_metadata_2025 huggingface dataset:
On‐farm dynamic management of genetic diversity: the impact of seed diffusions and seed saving practices on a population‐variety of bread wheat
Authors: Thomas Mathieu , Demeulenaere Elise , Dawson Julie C. , Khan Abdul Rehman , Galic Nathalie , Jouanne‐Pin Sophie , Remoue Carine , Bonneuil Christophe , Goldringer Isabelle
Published: April 2012

Since the domestication of crop species, humans have derived specific varieties for particular uses and shaped the genetic diversity of these varieties. Here, using an interdisciplinary approach combining ethnobotany and population genetics, we document the within‐variety genetic structure of a population‐variety of bread wheat (Triticum aestivum L.) in relation to farmers’ practices to decipher their contribution to crop species evolution. Using 19 microsatellites markers, we conducted two complementary graph theory‐based methods to analyze population structure and gene flow among 19 sub‐populations of a single population‐variety [Rouge de Bordeaux (RDB)]. The ethnobotany approach allowed us to determine the RDB history including diffusion and reproduction events. We found that the complex genetic structure among the RDB sub‐populations is highly consistent with the structure of the seed diffusion and reproduction network drawn based on the ethnobotanical study. This structure highlighted the key role of the farmer‐led seed diffusion through founder effects, selection and genetic drift because of human practices. An important result is that the genetic diversity conserved on farm is complementary to that found in the genebank indicating that both systems are required for a more efficient crop diversity conservation.
Chalcid parasitoid community associated with the invading pest Dryocosmus kuriphilus in north‐western Italy
Authors: QUACCHIA AMBRA , FERRACINI CHIARA , NICHOLLS JAMES A. , PIAZZA ENZO , SALADINI MATTEO A. , TOTA FEDERICA , MELIKA GEORGE , ALMA ALBERTO
Published: April 2012

Abstract.  1. Biological invasions of exotic species pose a major threat to native biodiversity. Invaders are known to have direct impacts on native species; however, less well studied are the indirect impacts mediated through the integration of invaders into trophically linked communities.

2. A survey of the chalcid wasp parasitoid community attacking the chestnut gallwasp Dryocosmus kuriphilus was carried out over a 5‐year period at 26 sites in north‐western Italy. More than 415 000 galls were collected and more than 10 000 parasitoid specimens emerged. Twenty‐seven parasitoid species belonging to six families (Eurytomidae, Pteromalidae, Torymidae, Eupelmidae, Ormyridae, Eulophidae) were identified using morphological and molecular methods; seventeen are new records for the parasitoid community associated with D. kuriphilus in Italy. The morphospecies complexes Megastigmus dorsalis, Eupelmus urozonus, E. annulatus, and Eurytoma pistaciae were the dominant species; another six morphospecies were encountered regularly but at low frequency; and 13 species were recorded only occasionally. The attack rate of any individual parasitoid species was low, although the more common species appeared to be increasing their use of this novel host.

3. Biases observed in the sex ratios of parasitoids emerging from D. kuriphilus galls suggest that parasitoid individuals are making life‐history decisions to take advantage of the high abundance of this host. Overall, these patterns imply that there is an ongoing transfer of parasitoids between oak and chestnut galls, and hence a high potential for this invading species to have a major impact on native oak gall communities via indirect competition mediated through shared parasitoids.
Eyelid skin disinfecting and conjunctival bacteria in cataract surgery
Authors: Ali Talal , Jung Karin , Montan Per G.
Published: April 2012

Purpose:  To evaluate the effect on conjunctival micro‐organisms of chlorhexidine alcohol 0.5% eyelid wash in cataract patients.

Methods:  In this single‐centre experimental study, 120 patients scheduled to undergo cataract operation were cultured in the conjunctiva before the operation and after the insertion of the intraocular lens. Bacterial samples for aerobic and anaerobic cultures were taken with a polyvinyl alcohol pad and transported in peptone water to the microbiological laboratory where they were analysed in a blinded fashion. Half of the patients received a standardized eyelid scrub with chlorhexidine alcohol 0.5%, while the rest did not. The conjunctiva of all patients was rinsed preoperatively with chlorhexidine solution 0.05%.

Results:  In all the between‐group comparisons, the treated eyelid group had slightly lower bacterial counts than the control group on the postoperative samples, but differences were far from statistically significant. Within‐group comparisons revealed statistically significant reduction in colonies and species between the preoperative and postoperative sampling.

Conclusion:  In this experimental culture study, no evidence was found to suggest that preoperative eyelid chlorhexidine alcohol wash is effective in further reducing bacterial counts in the conjunctiva when the conjunctiva itself is rinsed preoperatively with chlorhexidine solution. The present results, however, do not contradict that the wash may be of some marginal help in reducing bacterial contamination of the operation field. Consequently, this part of the prophylactic protocol is still in practice in our institution.
Epithelial tumours of the lacrimal gland: a clinical, histopathological, surgical and oncological survey
Authors: von Holstein Sarah Linéa , Coupland Sarah E , Briscoe Daniel , Le Tourneau Christophe , Heegaard Steffen
Published: April 2012

Epithelial tumours of the lacrimal gland represent a large spectrum of lesions with similarities in clinical signs and symptoms but with different biological behaviour and prognosis. They are rare, but with aggressive malignant potential. Tumours of the lacrimal gland may present with swelling of the lacrimal gland, displacement of the eyeball, reduced eye motility and diplopia. Pain and symptoms of short duration before the first ophthalmic consultation are characteristic of malignant tumours. The histological diagnosis determines the subsequent treatment regimen and provides important clues regarding the prognosis. The purpose of this paper is to describe the various primary epithelial tumours of the lacrimal gland. In the first part of the review, the frequency, demographics, clinical presentation and diagnostic features are described. In the second part, primarily tumour‐specific histological characteristics are given. Finally, treatment modalities including surgical procedures and medical oncology as well as prognosis are discussed.
Lacrimal gland lesions in Denmark between 1974 and 2007
Authors: von Holstein Sarah Linéa , Therkildsen Marianne Hamilton , Prause Jan Ulrik , Stenman Göran , Siersma Volkert Dirk , Heegaard Steffen
Published: April 2012

Purpose:  To evaluate the incidence rate, distribution, patient characteristics and indications for surgical intervention of lacrimal gland lesions in Denmark between 1974 and 2007.

Material and methods:  All biopsied/surgically removed lacrimal gland lesions in Denmark during the period 1974–2007 were identified by searching two population‐based registries. Specimens were collected and re‐evaluated. The following data were collected: age, gender, indications for surgical intervention and local recurrence.

Results:  A total of 232 lesions from 210 patients with a histologically verified lesion of the lacrimal gland were included. The incidence rate of lacrimal gland lesions was 1.3/1 000 000/year. The overall annual age‐ and gender‐adjusted incidence rate more than doubled during the study period, owing to an increase in non‐malignant lesions. Approximately half of the lesions were neoplasms (119) and 55% (66) of these were malignant. Dacryops constituted 10% (24), inflammatory lesions 27% (62), normal tissue 12% (27), benign tumours 23% (53) and malignant tumours 29% (66). Patients with malignant neoplasms were significantly older than patients with benign neoplasms (63 versus 48 years, p < 0.001). The indication for surgical intervention was suspicion of a tumour in more than 90% of the neoplastic lesions and in 30% of the non‐neoplastic lesions.

Conclusion:  Lacrimal gland lesions that require surgical evaluation are rare in the Danish population and represent a wide spectrum of diagnoses, mostly benign. The overall incidence rate of biopsied lacrimal gland lesions is increasing.
Of ‘Origins and Essences’: Aboriginal Conception Ideology and Anthropological Conceptions of Aboriginal Local Organization1
Authors: Shapiro Warren
Published: April 2012

… myths often speak of archetypes in terms of prototypes. They describe the absolute nature of reality as the first and original one … by ‘first’ they mean ‘always’. Adam is relevant to us because he represents the essential man (an archetype), not just the first man (prototype). His ‘original sin’ is thus ours: it is inherent in the human condition. We do not inherit such sin just through time, genetically, like some sort of proclivity for contracting a disease or for playing the piano. Rather, we inherit it to the extent we inherit our humanity; we inherit it through the form. … The archetypical beginnings described in creation myths are absolute and essential. Their truths are always valid. We are so accustomed to thinking historically and linearly, placing the past ‘back there’, that this notion is somewhat difficult for us to grasp. … But it is not inscrutable if you think of time cyclically, repeating itself like the seasons. … It is also easier to understand if you envision the past as ‘deep within’, at the core, like the first age ring of a tree's growth (Sproul 1979:27–28).
An Experimental Test of Women's Body Dissatisfaction Reduction through Self‐Affirmation
Authors: Bucchianeri Michaela M. , Corning Alexandra F.
Published: April 2012

Background: Body dissatisfaction (BD)—a health concern in its own right—often is positioned early in the causal chain toward eating pathology, and is a practical point of intervention for those aiming to reduce its negative health consequences. One approach to reducing people's resistance to receipt of other unwanted health information (e.g. about smoking) has been through the application of self‐affirmation theory. This theory asserts that the self needs to maintain its integrity and, as such, when incoming information is threatening, one's defensive shields are activated and it is deflected. One way to reduce defensiveness, however, is to bolster some other aspect of the self. Method: We applied a one‐shot, self‐affirmation‐based manipulation via a randomised controlled design (N = 86) to a group of body‐dissatisfied college women and compared its effects to a control group. Results: All hypotheses predicted by self‐affirmation theory were supported: Women who were self‐affirmed exhibited (a) greater openness to threatening information about the dangers of BD, (b) lower BD, and (c) greater intention to reduce criticism of their bodies. Conclusions: The present study provided an experimental test of a mechanism of action which might prove useful in a comprehensive intervention program.
Structural Autografts Used in Reconstruction of the Elbow Joint
Authors: Ng Chye Yew , Sabo Marlis T. , Watts Adam C.
Published: April 2012

The elbow joint is susceptible to osteochondral injuries related to complex fracture-dislocations, as well as to conditions such as osteochondritis dissecans. In many instances, the repair of fragments or fibrocartilage-stimulating techniques are sufficient to treat the defects but, in some patients, this is either not feasible or has failed. In these situations, osteochondral autografts provide reconstructive options. The present review discusses reconstructive options for the coronoid, radial head and capitellum using autografts.
‘Piggy-Back’ Customized (Cadcam) Total Shoulder Arthroplasty for Extreme Dysmorphism of the Scapula and Humerus
Authors: Noorani Ali M. , Panagiotidou Anna , Pandit Adam N. , Donaldson James , Higgs Deborah , Lambert Simon M.
Published: April 2012

We present a case of extreme glenohumeral dysmorphism with pain and arthropathy which benefited from a Computer-Aided Design and Computer-Aided Manufacture (CADCAM) ‘Piggy-Back’ reverse total shoulder arthroplasty.
Enamel demineralization and bracket bond strength when etching with acid and /or Er:YAG laser
Authors: Lasmar MF , Reher VGS , Lalloo R , Reher P
Published: April 2012

Background:  Enamel etching for brackets is usually done with phosphoric acid. Er:YAG lasers have been recently used for this purpose with conflicting results. The effects of lasers on tooth demineralization and the effects of different combinations of laser treatments and bonding agents were evaluated in this study.

Methods:  The enamel contents of fluorine, calcium oxide and phosphorus pentoxide (P2O5) were analysed using acid etching, laser treatment or both. The tensile bond strength of metallic and ceramic brackets using Transbond® XT and Fuji Ortho® LC were also tested, using acid etching, laser treatment or a combination of both.

Results:  All treatments reduced the contents of fluorine, P2O5 and calcium oxide, and acid reduced P2O5 levels more than laser. The bond strength with laser was weaker than with acid, and stronger when combining both. When using laser, the best adhesive was the Fuji Ortho® LC. The combination of laser and acid produced the best results when using Transbond® XT.

Conclusions:  The demineralization promoted by laser was lower than the one produced with acid. Laser treatment produced lower tensile stress strength than acid, but still enough to produce clinically efficient retention. The combination of laser and acid produced the best retention results.
Impact of interleukin‐28B genotype on in vitro and in vivo systems of hepatitis C virus replication
Authors: Chayama Kazuaki , Hayes C. Nelson , Imamura Michio
Published: April 2012

Identification of the relationship between the interleukin (IL)‐28B genotype and the effect of peginterferon plus ribavirin treatment has had a great impact on the study of antiviral therapy for patients with chronic hepatitis C virus (HCV) infection. Differential expression levels of interferon‐stimulated genes (ISG) in the liver and white blood cells based on the IL‐28B genotype, which may in turn lead to differences in outcome of therapy, indicate that previous studies should be re‐evaluated taking the effect of the IL‐28B single nucleotide polymorphism (SNP) into consideration, although the exact mechanism of how variation in IL‐28B SNPs affect HCV eradication remains unknown. These results suggest that the genotypes of multiple cell types, including liver and immune cells, contribute to the efficacy of therapy. Studies using human hepatocyte chimeric mice, in which effector cells of the human adaptive immune response are absent, showed that viral load, ISG expression levels and reduction of HCV RNA by interferon are affected by the IL‐28B genotype. Genetic differences among hepatocytes may, therefore, contribute to differences in baseline viral loads and response to interferon therapy. Further studies should be done to clarify the mechanism of action of IL‐28B SNP on viral load and effect of interferon treatment. Advances in cell culture systems and human hepatocyte chimeric mice, as well as upcoming in vitro and in vivo experimental systems, provide an effective platform to examine the effects of host and viral genetic variation on infection and response to interferon.
Prediction of recurrence of hepatocellular carcinoma after curative hepatectomy using preoperative Lens culinaris agglutinin‐reactive fraction of alpha‐fetoprotein
Authors: Saito Yu , Shimada Mitsuo , Utsunomiya Tohru , Morine Yuji , Imura Satoru , Ikemoto Tetsuya , Mori Hiroki , Hanaoka Jun , Yamada Shinichiro , Asanoma Michihito
Published: April 2012

Aim:  Lens culinaris agglutinin A‐reactive fraction of α‐fetoprotein (AFP‐L3) status has been reported to be an independent prognostic factor in patients with hepatocellular carcinoma (HCC). In this study, we evaluated the clinical usefulness of measuring preoperative AFP‐L3 to predict the recurrence and prognosis of HCC after curative hepatectomy.

Methods:  One hundred and forty‐two HCC patients who underwent curative hepatectomy were examined for the correlation between preoperative tumor marker, including AFP, des‐γ‐carboxy prothrombin (DCP) and AFP‐L3, and clinicopathological variables. The prognostic factors of disease‐free survival rates and overall survival rates were also determined using clinicopathological variables including these three tumor markers.

Results:  There were similar tendencies in the relationship between these three markers and malignant behaviors including lower grade tumor differentiation or vascular invasion. In multivariate analysis, increased AFP‐L3 value (P = 0.019) was found to be an independent prognostic factor of disease‐free survival after curative hepatectomy. In addition, elevated DCP (P = 0.013) and AFP‐L3 values (P = 0.012) were found to be independent prognostic factors. Furthermore, the preoperative AFP‐L3 value in the patients with early recurrence (within 1 year after hepatectomy) was significantly higher than that in those without early recurrence (26.9 ± 19.5 % vs 14.2 ± 19.8 %, P = 0.047).

Conclusion:  Preoperative AFP‐L3 value was strongly correlated to disease‐free and overall survival rate and the timing of recurrence, so it appears that it would be useful to predict the recurrence and prognosis of HCC after curative hepatectomy.
Efficacy and safety of prophylaxis with entecavir and hepatitis B immunoglobulin in preventing hepatitis B recurrence after living‐donor liver transplantation
Authors: Ueda Yoshihide , Marusawa Hiroyuki , Kaido Toshimi , Ogura Yasuhiro , Ogawa Kohei , Yoshizawa Atsushi , Hata Koichiro , Fujimoto Yasuhiro , Nishijima Norihiro , Chiba Tsutomu , Uemoto Shinji
Published: April 2012

Aim:  Hepatitis B recurrence after liver transplantation can be reduced to less than 10% by combination therapy with lamivudine (LAM) and hepatitis B immunoglobulin (HBIG). The aim of this study was to evaluate the efficacy and safety of prophylaxis with entecavir (ETV), which has higher efficacy and lower resistance rates than LAM, combined with HBIG in preventing hepatitis B recurrence after living‐donor liver transplantation (LDLT).

Methods:  Twenty‐six patients who received ETV plus HBIG (ETV group) after LDLT for hepatitis B virus (HBV)‐related end‐stage liver disease were analyzed by comparing with 63 control patients who had received LAM plus HBIG (LAM group).

Results:  The survival rates of the patients treated with ETV plus HBIG was 73% after both 1 and 3 years, and there was no statistical difference between the patients in the ETV group and LAM group. No HBV recurrence was detected during the median follow‐up period of 25.1 months in the ETV group, whereas the HBV recurrence rate was 4% at 3 years and 6% at 5 years in the LAM group. No patients had adverse effects related to ETV administration.

Conclusion:  ETV combined with HBIG provides effective and safe prophylaxis in preventing hepatitis B recurrence after LDLT.
Importance of the Effective Strong Ion Difference of an Intravenous Solution in the Treatment of Diarrheic Calves with Naturally Acquired Acidemia and Strong Ion (Metabolic) Acidosis
Authors: Müller K.R. , Gentile A. , Klee W. , Constable P.D.
Published: April 2012

Background

The effect of sodium bicarbonate on acid‐base balance in metabolic acidosis is interpreted differently byHenderson‐Hasselbalch and strong ion acid‐base approaches. Application of the traditional bicarbonate‐centric approach indicates that bicarbonate administration corrects the metabolic acidosis by buffering hydrogen ions, whereas strong ion difference theory indicates that the co‐administration of the strong cation sodium with a volatile buffer (bicarbonate) corrects the strong ion acidosis by increasing the strong ion difference (SID) in plasma.

Objective

To investigate the relative importance of the effectiveSIDofIVsolutions in correcting acidemia in calves with diarrhea.

Animals

Twenty‐twoHolstein‐Friesian calves (4–21 days old) with naturally acquired diarrhea and strong ion (metabolic) acidosis.

Methods

Calves were randomly assigned toIVtreatment with a solution of sodium bicarbonate (1.4%) or sodium gluconate (3.26%). Fluids were administered over 4 hours and the effect on acid‐base balance was determined.

Results

Calves suffered from acidemia owing to moderate to strong ion acidosis arising from hyponatremia and hyper‐d‐lactatemia. Sodium bicarbonate infusion was effective in correcting the strong ion acidosis. In contrast, sodium gluconate infusion did not change bloodpH, presumably because the strong anion gluconate was minimally metabolized.

Conclusions

A solution containing a high effectiveSID(sodium bicarbonate) is much more effective in alkalinizing diarrheic calves with strong ion acidosis than a solution with a low effectiveSID(sodium gluconate). Sodium gluconate is ineffective in correcting acidemia, which can be explained using traditional acid‐base theory but requires a new parameter, effectiveSID, to be understood using the strong ion approach.
Recent Advances and Emerging Applications of the Boundary Element Method
Authors: Liu Y. J. , Mukherjee S. , Nishimura N. , Schanz M. , Ye W. , Sutradhar A. , Pan E. , Dumont N. A. , Frangi A. , Saez A.
Published: April 2012

Sponsored by the U.S. National Science Foundation, a workshop on the boundary element method (BEM) was held on the campus of the University of Akron during September 1–3, 2010 (NSF, 2010, “Workshop on the Emerging Applications and Future Directions of the Boundary Element Method,” University of Akron, Ohio, September 1–3). This paper was prepared after this workshop by the organizers and participants based on the presentations and discussions at the workshop. The paper aims to review the major research achievements in the last decade, the current status, and the future directions of the BEM in the next decade. The review starts with a brief introduction to the BEM. Then, new developments in Green's functions, symmetric Galerkin formulations, boundary meshfree methods, and variationally based BEM formulations are reviewed. Next, fast solution methods for efficiently solving the BEM systems of equations, namely, the fast multipole method, the pre-corrected fast Fourier transformation method, and the adaptive cross approximation method are presented. Emerging applications of the BEM in solving microelectromechanical systems, composites, functionally graded materials, fracture mechanics, acoustic, elastic and electromagnetic waves, time-domain problems, and coupled methods are reviewed. Finally, future directions of the BEM as envisioned by the authors for the next five to ten years are discussed. This paper is intended for students, researchers, and engineers who are new in BEM research and wish to have an overview of the field. Technical details of the BEM and related approaches discussed in the review can be found in the Reference section with more than 400 papers cited in this review.
Integrator Leakage for Limit Cycle Suppression in Servo Mechanisms With Stiction
Authors: Jeon Soo
Published: April 2012

It is well known that the positional proportional-integral-derivative (PID) control of a servo mechanism with stiction always leads to a limit cycle. Related to this fact, two basic questions have still remained unanswered. The first question is, if the limit cycle occurs, how large it becomes for a given value of stiction force. The second question, which is of more practical importance, is how we should modify the PID controller to avoid this limit cycle with minimal sacrifice of the servo performance. This paper presents a rigorous analysis to provide particular answers to these two questions, which turn out to be closely related to each other. More specifically, it is shown that, by exploiting algebraic properties of the state trajectory, a simple bisection algorithm can be devised to compute the exact magnitude of the periodic solution for a given value of stiction. Through the geometric analysis of the impact map, this result is then used to find the minimum value of the integrator leakage to avoid the limit cycle. The work in this paper will be useful as a specific reference in designing servo mechanisms with stiction free from limit cycle.
Sliding Mode Control of Both Air-to-Fuel and Fuel Ratios for a Dual-Fuel Internal Combustion Engine
Authors: Pace Stephen , Zhu Guoming G.
Published: April 2012

A multi-input-multi-output (MIMO) sliding mode control scheme was developed with guaranteed stability to simultaneously control air-to-fuel ratio (AFR) and fuel ratios to desired levels under various air flow disturbances by regulating the mass flow rates of engine port-fuel-injection (PFI) and direct injection (DI) systems. The sliding mode control performance was compared with a baseline multiloop proportional integral differential (PID) controller through simulations and showed improvements. A four cylinder mean value engine model and the proposed sliding mode controller were implemented into a hardware-in-the-loop (HIL) simulator and a target engine control module, and HIL simulations were conducted to validate the developed controller for potential implementation in an automotive engine.
Nonlinear Dynamic Analysis of Single-Walled Carbon Nanotube Based Mass Sensor
Authors: Joshi Anand Y. , Sharma Satish C. , Harsha S. P.
Published: April 2012

In previous studies, experimentally measured resonance frequencies of carbon nanotubes have been used along with classical beam theory for straight beams. However, it is found that these carbon nanotubes are not straight, and that they have some significant surface deviation associated with them. This paper deals with the nonlinear vibration analysis of a wavy single-walled carbon nanotube based mass sensor, which is doubly clamped at a source and a drain. Nonlinear oscillations of a single-walled carbon nanotube excited harmonically near its primary resonance are considered. The carbon nanotube is excited by the addition of an excitation force. The modeling is carried out using the elastic continuum beam theory concept, which involves stretching of the central plane and phenomenological damping. This model takes into account the existence of waviness in carbon nanotubes. The equation of motion involves two nonlinear terms due to the curved geometry and the stretching of the central plane. The dynamic response of the carbon nanotube based mass sensor is analyzed in the context of the time response, Poincaré maps, and fast Fourier transformation diagrams. The results show the appearance of instability and chaos in the dynamic response as the mass on carbon nanotube is changed. Period doubling and mechanism of intermittency have been observed as the routes to chaos. The appearance of regions of periodic, subharmonic, and chaotic behavior is observed to be strongly dependent on mass and the geometric imperfections of carbon nanotube. Poincaré maps and frequency spectra are used to elucidate and to illustrate the diversity of the system behavior.
Experiments in Nanomechanical Properties of Live Osteoblast Cells and Cell–Biomaterial Interface
Authors: Khanna Rohit , Katti Kalpana S. , Katti Dinesh R.
Published: April 2012

Characterizing the mechanical characteristics of living cells and cell–biomaterial composite is an important area of research in bone tissue engineering. In this work, an in situ displacement-controlled nanoindentation technique (using Hysitron Triboscope) is developed to perform nanomechanical characterization of living cells (human osteoblasts) and cell–substrate constructs under physiological conditions (cell culture medium; 37 °C). In situ elastic moduli (E) of adsorbed proteins on tissue culture polystyrene (TCPS) under cell culture media were found to be ∼4 GPa as revealed by modulus mapping experiments. The TCPS substrates soaked in cell culture medium showed significant difference in surface nanomechanical properties (up to depths of ∼12 nm) as compared to properties obtained from deeper indentations. Atomic force microscopy (AFM) revealed the cytoskeleton structures such as actin stress fiber networks on flat cells which are believed to impart the structural integrity to cell structure. Load-deformation response of cell was found to be purely elastic in nature, i.e., cell recovers its shape on unloading as indicated by linear loading and unloading curves obtained at 1000 nm indentation depth. The elastic response of cells is obtained during initial cell adhesion (ECell, 1 h, 1000 nm = 4.4–12.4 MPa), cell division (ECell, 2 days, 1000 nm = 1.3–3.0 MPa), and cell spreading (ECell, 2 days, 1000 nm = 6.9–11.6 MPa). Composite nanomechanical responses of cell–TCPS constructs were obtained by indentation at depths of 2000 nm and 3000 nm on cell-seeded TCPS. Elastic properties of cell–substrate composites were mostly dominated by stiff TCPS (EBulk = 5 GPa) lying underneath the cell.
Productivity Enhancement of Solar Still Using Water Heater and Cooling Fan
Authors: Al-Garni Ahmed Z.
Published: April 2012

In the present work, an attempt is made to enhance the productivity of a double slope solar still by using an immersion type water heater. The effect of using an external fan to cool the glass surface is also examined. Experiments were carried out for winter season in Saudi Arabian climatic conditions at latitude 26 deg N. A solar still with 35 deg glass slope angle is chosen in our study. Since the yield of a solar still is more for low water depths, the water level in the base tank was maintained at 1 cm. The experimental results showed that the productivity increased by a significant 370% when two water heaters each having 500 W capacities was used. When external cooling fan was used the productivity was found to decrease by 4% and 8% for wind speeds of 7 m/s and 9 m/s, respectively. Thermal modeling was also done using the heat and mass transfer relations, and then, numerical simulations were carried out to validate with the experimental results. A good agreement between experimental and numerical results was found. The present study is partial implementation of two patents submitted in this field.
A Simplified Model for Assessing the Work-Hardening Effect in the Analysis of Plate Drawing Processes by Upper Bound Method
Authors: Rubio E. M. , Sanz-Lobera A. , Marcos M. , Sebastián M. A.
Published: April 2012

This work presents an analysis of the plate drawing processes carried out in converging dies. The analysis has been made by the upper bound method (UBM), modeling the plastic deformation zone by triangular rigid zones (TRZ), and considering that the processes occur under plane strain and partial friction conditions. The goal is to evaluate how the work-hardening suffered by materials when they are cold-worked affects the energy required to carry out a certain process. In order to achieve this objective, the paper proposes a simplified model for calculating the shear yield stress, k, along the contact surface between die and material when theoretical work-hardening materials are used. The results obtained with this simplified procedure do not differ significantly from those obtained with the complete model, even in the more drastic conditions tried. This result confirms that the simplified model can successfully substitute for the complete model with less calculation.
Chip Flow and Scaling Laws in High Speed Metal Cutting
Authors: Sutter Guy , Molinari Alain , List Gautier , Bi Xuefeng
Published: April 2012

Chip formation in machining plays an important role in the cutting process optimisation. Chip morphology often reflects the choice of cutting conditions, the tool wear and by consequences the integrity of the machined surface and tool life. In this study, photographs of the chip morphology during high speed machining of a middle hard steel (C20 similar to AISI 1020) are taken by using a ballistic setup. From these recordings, the evolution of the chip morphology is presented and analysed in terms of cutting conditions. A simplified modeling is then proposed by considering the workpiece material as elastic perfectly plastic. The existence of a scaling law governing the chip morphology in high speed machining is demonstrated. The cutting velocity is shown to have a weak effect at high speed machining as opposed to the well known strong influence of the velocity in the range of low cutting speeds.
An Inverse Heat Transfer Method for Determining Workpiece Temperature in Minimum Quantity Lubrication Deep Hole Drilling
Authors: Tai Bruce L. , Stephenson David A. , Shih Albert J.
Published: April 2012

This study investigates the workpiece temperature in minimum quantity lubrication (MQL) deep hole drilling. An inverse heat transfer method is developed to estimate the spatial and temporal change of heat flux on the drilled hole wall surfaces based on the workpiece temperature measured using embedded thermocouples and analyzed using the finite element method. The inverse method is validated experimentally in both dry and MQL deep-hole drilling conditions and the results show good agreement with the experimental temperature measurements. This study demonstrates that the heat generated on the hole wall surface is significant in deep hole drilling. In the example of deep hole drilling of ductile iron, the level of thermal power applied on the hole wall surface is about the same as that on the hole bottom surface when a 10 mm drill reached a depth of 120 mm.
Analytical Modeling and Simulation of the Envelope Surface in Five-Axis Flank Milling With Cutter Runout
Authors: Sun Yuwen , Guo Qiang
Published: April 2012

The cutter runout effect has significant influence on the shape of the cutter swept surface and the machining surface quality. Due to the existence of cutter runout effect, the shape and position of envelope surface formed by each cutter edge are different from others. Hence, it is necessary to integrate the cutter runout effect and its resulting compound effects of all cutter edges into envelope surface modeling and form error prediction for five-axis milling. This paper establishes the envelope surface model considering cutter runout effect in five-axis flank milling based on the relative motion analysis of the cutter and part. In this model, the cutter runout is defined by three parameters, including inclination angle, location angle, and offset value, and the cutter runout effect is subsequently integrated into the model by using the cutter edge as the generatrix of cutter rotation surface. Then, the influence of each runout parameter on the shape of envelope surface formed by each cutter edge as well as the resulting form error in milling is investigated. Also, the compound effects of all cutter edges on the final resulting geometric errors of the machined surface are analyzed. Finally, simulations and machining experiment are conducted for a specific ruled surface, and the results validate the effectiveness and feasibility of proposed envelope surface model considering cutter runout effect. It is suitable to be used in tool positioning, tool installation adjustment, and forming error prediction in flank milling process with cutter runout.
Combustion Characteristics of Biofuels in Porous-Media Burners at an Equivalence Ratio of 0.8
Authors: Barajas Pablo E. , Parthasarathy R. N. , Gollahalli S. R.
Published: April 2012

Biofuels, such as canola methyl ester (CME) and soy-methyl ester (SME) derived from vegetable oil, are alternative sources of energy that have been developed to reduce the dependence on petroleum-based fuels. In the present study, CME, SME, and commercial Jet-A fuel were tested in a porous-media burner at an equivalence ratio of 0.8 at the burner entrance. The measured combustion characteristics included NOx and CO emission indices, radiative fraction of heat release, and axial temperature profile in the surface stabilized and extended flame. The effects of fuel on the injector and porous-media durability were also documented. The NOx emission index was higher for the SME and CME flames than that of the Jet-A flame. Furthermore, the axial temperature profiles were similar for all the flames. The prolonged use of CME and SME resulted in more solid-particle deposition on the interior walls of the injector and within the structure of the porous medium than for Jet-A fuel, thereby increasing the restriction to the fuel/air flow and pressure drop across the burner.
Design by Analogy: A Study of the WordTree Method for Problem Re-Representation
Authors: Linsey J. S. , Markman A. B. , Wood K. L.
Published: April 2012

This paper presents a novel approach, referred to as the WordTree design-by-analogy method, for identifying distant-domain analogies as part of the ideation process. The WordTree method derives its effectiveness through a design team’s knowledge and readily available information sources (e.g., patent databases, Google) and does not require specialized computational knowledge bases. A controlled cognitive experiment and an evaluation of the method with redesign projects illustrate the method’s influence in assisting engineers in design-by-analogy. Individuals using the WordTree method identified significantly more analogies and searched outside the problem domain as compared to the control group. The team redesign projects demonstrate the WordTree method’s effectiveness in longer-term, more realistic, higher validity team projects and with a variety of different design problems. Teams successfully identified effective analogies, analogous domains, and analogous patents. Unexpected and unique solutions are identified using the method. For example, one of the teams identified a dump truck and panning for gold as effective analogies for the design of a self-cleaning cat litter box. In the controlled experiment, a cherry pitter was identified and implemented as a solution for designing a machine to shell peanuts. The experimental results also highlight potential improvements for the method and areas for future research in engineering design theory.
Validation of Function Pruning Rules Through Similarity at Three Levels of Abstraction
Authors: Caldwell Benjamin W. , Mocko Gregory M.
Published: April 2012

Function modeling is often used in the conceptual design phase as an approach to capture a form-independent purpose of a product. Previous research uses a repository of reverse-engineered function models to support conceptual-based design tools, such as similarity and design-by-analogy. These models, however, are created at a different level of abstraction than models created in conceptual design for new products. In this paper, a set of pruning rules is developed to generate an abstract, conceptual-level model from a reverse-engineered function model. The conceptual-level models are compared to two additional levels of abstraction that are available in a design repository. The abstract models developed through the pruning rules are tested using a similarity metric to understand their usefulness in conceptual design. The similarity of 128 products is computed using the Functional Basis controlled vocabulary and a matrix-based similarity metric at each level of abstraction. A matrix-based clustering algorithm is then applied to the similarity results to identify groups of similar products. A subset of these products is studied to further compare the three levels of abstraction and to validate the pruning rules. It is shown that the pruning rules are able to convert reverse-engineered function models to conceptual-level models, better supporting design-by-analogy, a conceptual-stage design activity.
Contact Stress and Root Stress Analyses of Thin-Rimmed Spur Gears With Inclined Webs
Authors: Li Shuting
Published: April 2012

Loaded tooth contact analysis (LTCA), deformation, and stress calculations of three types of thin-rimmed spur gears with inclined webs at the left side, the center, and the right side of the tooth are conducted in this paper with finite element methods (FEM) combined with a mathematical programming method when these gears are engaged with a solid mating gear. The contact stresses on the tooth surfaces, the bending stresses at the tooth roots, and the joint stresses of the rim and the web are analyzed as the web position and the web angle are changed. It was found that the web position and the web angle of the thin-rimmed gears have a significant effect on the tooth contact stresses, the root bending stresses, and the joint stresses. The maximum contact stress of the right web gear becomes very small when the web is inclined from 0 to 30 deg, and it increases again when the web angles are changed from 45 to 60 deg. This interesting relationship between the web angle and the tooth contact stresses of thin-rimmed right inclined web gears is used to absorb the misalignment errors in the gears and improve the partial tooth contact pattern resulting from the misalignment errors. A calculation example is provided to illustrate how to improve the partial tooth contact patterns in gears with misalignment errors.
Effects of Bearing Preload, Oil Volume, and Operating Temperature on Axle Power Losses
Authors: Xu Hai , Singh Avinash , Kahraman Ahmet , Hurley Joshua , Shon Sam
Published: April 2012

In order to boost the fuel economy of their vehicles, automotive Original Equipment Manufacturers (OEMs) and suppliers have been investigating a range of options from alternate vehicle propulsion systems down to optimized component level technologies. The hypoid gear set in a rear axle is one of the least efficient drive train components, and as such, provides unique opportunities for improvements. It has therefore attracted significant attention from researchers to reduce the power losses. Both loaded and unloaded power losses have been studied before and found to vary significantly with load and speed conditions. This paper will focus on the effects of the axle pinion bearing preload, axle gear oil levels, and operating temperatures on axle power losses during the fuel economy driving cycles where both axle load and speed vary significantly. In this paper, power loss measurements from experiments conducted on an automotive rear drive axle on a dedicated dynamometer will be presented. Tests were conducted under a range of speed and load conditions that were developed from Environmental Protection Agency (EPA) fuel economy driving cycles. Both urban and highway cycles were included in the tests. Separate tests were conducted for unloaded spin losses and loaded power losses. The tests were conducted at a few different controlled levels of gear oil operating temperatures, gear oil volumes, and pinion bearing preloads, and their influence on power losses was quantified. The measured power losses at a matrix of load and speed conditions provide a series of power loss maps as a function of gear oil operating temperature, oil volume, and bearing preload. Using these power loss maps, the overall axle efficiency or power loss during any driving cycle can be quantified by integrating the instantaneous power losses as the axle goes through the driving cycles. Similar maps can be created for other influences and the proposed procedure can be utilized to quantify their influences on a given driving cycle. Results from this study indicate that with the combination of appropriate preloads, gear oil volume, and temperature control, axle efficiency can potentially be improved by roughly 3% in the tested axle.
Concentrating Solar Power in Europe, the Middle East and North Africa: A Review of Development Issues and Potential to 2050
Authors: Pitz-Paal Robert , Amin Amr , Oliver Bettzuge Marc , Eames Philip , Flamant Gilles , Fabrizi Fabrizio , Holmes John , Kribus Avi , van der Laan Harry , Lopez Cayetano , Garcia Novo Francisco , Papagiannakopoulos Panos , Pihl Erik , Smith Paul , Wagner Hermann-Josef
Published: April 2012

This paper summarizes the findings of a study undertaken by the European Academies Science Advisory Council to evaluate the development challenges of concentrating solar power (CSP) and its consequent potential to contribute to low carbon electricity systems in Europe, the Middle East and North Africa (the MENA region) to 2050. The study reviewed the current status and prospective developments of the four main CSP technology families, and identified prospective technical developments, quantifying anticipated efficiency improvements and cost reductions. Similarly, developments in thermal energy storage were evaluated, and the role and value of CSP storage in electricity systems were examined. A key conclusion was that as the share of intermittent renewables in an electricity system increases, so does the value of thermal energy storage in CSP plants. Looking ahead, the study concludes that CSP should be cost competitive with fossil-fired power generation at some point in the 2020’s provided that commercial deployment continues at an increasing rate, and through support mechanisms that incentivise technology development. Incentive schemes should reflect the real value of electricity to the system, and should ensure sufficient transparency of cost data that learning rates can be monitored. Key factors which will determine CSP’s contribution in Europe and the MENA region over the period to 2050 are generating costs, physical constraints on construction of new plants and transmission, and considerations of security of supply. The study makes recommendations to European and MENA region policy makers on how the associated issues should be addressed.
Next-Day Daily Energy Consumption Forecast Model Development and Model Implementation
Authors: Song Li , Joo Ik-seong , Gunawan Subroto
Published: April 2012

Thermal storage systems were originally designed to shift on-peak cooling production to off-peak cooling production in order to reduce on-peak electricity demand. Recently, however, the reduction of both on- and off-peak demand is a critical issue. Reduction of on- and off-peak demand can also extend the life span and defer or eliminate the replacement of power transformers. Next day electricity consumption is a critical set point to operate chillers and associated pumps at the appropriate time. In this paper, a data evaluation process using the annual daily average cooling consumption of a building was conducted. Three real-time building load forecasting models were investigated: a first-order autoregressive model (AR(1)), an autogressive integrated moving average model (ARIMA(0,1,0)), and a linear regression model. A comparison of results shows that the AR(1) and ARIMA(0,1,0) models provide superior results to the linear regression model, except that the AR(1) model has a few unacceptable spikes. A complete control algorithm integrated with a corrected AR(1) forecast model for a chiller plant including chillers, thermal storage system, and pumping systems was developed and implemented to verify the feasibility of applying this algorithm in the building automation system. Application results are also introduced in the paper.