Nonlinear Interactions in a Piezoceramic Bar Transducer Powered by a Vacuum Tube Generated by a Nonideal Source

Interactions between the oscillations of piezoceramic transducer and the mechanism of as excitation-the generator of the electric current of limited power-supply-are analyzed in this paper In practical situations, the dynamics of the forcing function on a vibrating system cannot be considered as given a priori, and it must be taken as a consequence of the dynamics of the whole system. In other words, the forcing source has limited power as that provided by a dc motor for an example, and thus its own dynamics is influenced by that of the vibrating system being forced. This increases the number of degrees of freedom of the problem, and it is called a nonideal problem. In this work, we present certain phenomena as Sommerfeld effect, jump, saturation, and stability, through the influences of the parameters of the governing equations motion. [DOI: 10.1115/1.3007909]

An estimate of biometric parameters in eucalyptus clone plantations in Southern Bahia: an application of the airborne laser scanning (ALS) technology

The application of airborne laser scanning (ALS) technologies in forest inventories has shown great potential to improve the efficiency of forest planning activities. Precise estimates, fast assessment and relatively low complexity can explain the good results in terms of efficiency. The evolution of GPS and inertial measurement technologies, as well as the observed lower assessment costs when these technologies are applied to large scale studies, can explain the increasing dissemination of ALS technologies. The observed good quality of results can be expressed by estimates of volumes and basal area with estimated error below the level of 8.4%, depending on the size of sampled area, the quantity of laser pulses per square meter and the number of control plots. This paper analyzes the potential of an ALS assessment to produce certain forest inventory statistics in plantations of cloned Eucalyptus spp with precision equal of superior to conventional methods. The statistics of interest in this case were: volume, basal area, mean height and dominant trees mean height. The ALS flight for data assessment covered two strips of approximately 2 by 20 Km, in which clouds of points were sampled in circular plots with a radius of 13 m. Plots were sampled in different parts of the strips to cover different stand ages. The clouds of points generated by the ALS assessment: overall height mean, standard error, five percentiles (height under which we can find 10%, 30%, 50%,70% and 90% of the ALS points above ground level in the cloud), and density of points above ground level in each percentile were calculated. The ALS statistics were used in regression models to estimate mean diameter, mean height, mean height of dominant trees, basal area and volume. Conventional forest inventory sample plots provided real data. For volume, an exploratory assessment involving different combinations of ALS statistics allowed for the definition of the most promising relationships and fitting tests based on well known forest biometric models. The models based on ALS statistics that produced the best results involved: the 30% percentile to estimate mean diameter (R(2)=0,88 and MQE%=0,0004); the 10% and 90% percentiles to estimate mean height (R(2)=0,94 and MQE%=0,0003); the 90% percentile to estimate dominant height (R(2)=0,96 and MQE%=0,0003); the 10% percentile and mean height of ALS points to estimate basal area (R(2)=0,92 and MQE%=0,0016); and, to estimate volume, age and the 30% and 90% percentiles (R(2)=0,95 MQE%=0,002). Among the tested forest biometric models, the best fits were provided by the modified Schumacher using age and the 90% percentile, modified Clutter using age, mean height of ALS points and the 70% percentile, and modified Buckman using age, mean height of ALS points and the 10% percentile.

PROPOSAL OF A PERFORMANCE MEASURING SYSTEM APPLIED TO AGRICULTURAL MECHANIZATION

The leaders` organizations of several different sectors have as characteristic to measure their own performance in a systematic way. However, this concept is still unusual in agricultural enterprises, including the mechanization sector. Mechanization has an important role on the production costs and to know its performance is a key factor for the agricultural enterprise success. This work was generated by the importance that measurement of performance has for the management and the mechanization impact on the production costs. Its aim is to propose an integrated performance measurement system to give support to agricultural management. The methodology was divided in two steps: adjustment of a conceptual model based on Balanced Score Card - BSC; application of the model in a study case at sugar cane mill. The adjustment and the application of the conceptual model allowed to obtain the performance index in a systematic way, that are associated to: costs and deadline ( traditionally used); control and improvement on the quality of operations and support process; environmental preservation; safety; health; employees satisfaction; development of information systems. The adjusted model helped the development of the performance measurement system for the mechanized management systems and the index allows an integrated view of the enterprise, related to its strategic objectives.

DNA sequences generated by BCH codes over GF(4)

The question raised by researchers in the field of mathematical biology regarding the existence of error-correcting codes in the structure of the DNA sequences is answered positively. It is shown, for the first time, that DNA sequences such as proteins, targeting sequences and internal sequences are identified as codewords of BCH codes over Galois fields.

An integrated molecular map of yellow passion fruit based on simultaneous maximum-likelihood estimation of linkage and linkage phases

The development of genetic maps for auto-incompatible species, such as the yellow passion fruit (Passiflora edulis Sims f.flavicarpa Deg.) is restricted due to the unfeasibility of obtaining traditional mapping populations based on inbred lines. For this reason, yellow passion fruit linkage maps were generally constructed using a strategy known as two-way pseudo-testeross, based on monoparental dominant markers segregating in a 1:1 fashion. Due to the lack of information from these markers in one of the parents, two individual (parental) maps were obtained. However, integration of these maps is essential, and biparental markers can be used for such an operation. The objective of our study was to construct an integrated molecular map for a full-sib population of yellow passion fruit combining different loci configuration generated from amplified fragment length polymorphisms (AFLPs) and microsatellite markers and using a novel approach based on simultaneous maximum-likelihood estimation of linkage and linkage phases, specially designed for outcrossing species. Of the total number of loci, approximate to 76%, 21%, 0.7%, and 2.3% did segregate in 1:1, 3:1, 1:2:1, and 1:1:1:1 ratios, respectively. Ten linkage groups (LGs) were established with a logarithm of the odds (LOD) score >= 5.0 assuming a recombination fraction : <= 0.35. On average, 24 markers were assigned per LG, representing a total map length of 1687 cM, with a marker density of 6.9 cM. No markers were placed as accessories on the map as was done with previously constructed individual maps.

SAGE transcript profiling of the juvenile cambial region of Eucalyptus grandis

Despite the importance of Eucalyptus spp. in the pulp and paper industry, functional genomic approaches have only recently been applied to understand wood formation in this genus. We attempted to establish a global view of gene expression in the juvenile cambial region of Eucalyptus grandis Hill ex Maiden. The expression profile was obtained from serial analysis of gene expression (SAGE) library data produced from 3- and 6-year-old trees. Fourteen-base expressed sequence tags (ESTs) were searched against public Eucalyptus ESTs and annotated with GenBank. Altogether 43,304 tags were generated producing 3066 unigenes with three or more copies each, 445 with a putative identity, 215 with unknown function and 2406 without an EST match. The expression profile of the juvenile cambial region revealed the presence of highly frequent transcripts related to general metabolism and energy metabolism, cellular processes, transport, structural components and information pathways. We made a quantitative analysis of a large number of genes involved in the biosynthesis of cellulose, pectin, hemicellulose and lignin. Our findings provide insight into the expression of functionally related genes involved in juvenile wood formation in young fast-growing E. grandis trees.

Optimization of preservative system in ophthalmic suspension with dexamethasone and polymyxin B

A simplex-lattice statistical project was employed to study an optimization method for a preservative system in an ophthalmic suspension of dexametasone and polymyxin B. The assay matrix generated 17 formulas which were differentiated by the preservatives and EDTA (disodium ethylene diamine-tetraacetate), being the independent variable: X-1 = chlorhexidine digluconate (0.010 % w/v); X-2 = phenylethanol (0.500 % w/v); X-3 = EDTA (0.100 % w/v). The dependent variable was the Dvalue obtained from the microbial challenge of the formulas and calculated when the microbial killing process was modeled by an exponential function. The analysis of the dependent variable, performed using the software Design Expert/W, originated cubic equations with terms derived from stepwise adjustment method for the challenging microorganisms: Pseudomonas aeruginosa, Burkholderia cepacia, Staphylococcus aureus, Candida albicans and Aspergillus niger. Besides the mathematical expressions, the response surfaces and the contour graphics were obtained for each assay. The contour graphs obtained were overlaid in order to permit the identification of a region containing the most adequate formulas (graphic strategy), having as representatives: X-1 = 0.10 ( 0.001 % w/v); X-2 = 0.80 (0.400 % w/v); X-3 = 0.10 (0.010 % w/v). Additionally, in order to minimize responses (Dvalue), a numerical strategy corresponding to the use of the desirability function was used, which resulted in the following independent variables combinations: X-1 = 0.25 (0.0025 % w/v); X-2 = 0.75 (0.375 % w/v); X-3 = 0. These formulas, derived from the two strategies (graphic and numerical), were submitted to microbial challenge, and the experimental Dvalue obtained was compared to the theoretical Dvalue calculated from the cubic equation. Both Dvalues were similar to all the assays except that related to Staphylococcus aureus. This microorganism, as well as Pseudomonas aeruginosa, presented intense susceptibility to the formulas independently from the preservative and EDTA concentrations. Both formulas derived from graphic and numerical strategies attained the recommended criteria adopted by the official method. It was concluded that the model proposed allowed the optimization of the formulas in their preservation aspect.

A novel two-chain proteinase inhibitor generated by circularization of a multidomain precursor protein

Female reproductive tissues of the ornamental tobacco amass high levels of serine proteinase inhibitors (PIs) for protection against pests and pathogens. These PIs are produced from a precursor protein composed of six repeats each with a protease reactive site. Here we show that proteolytic processing of the precursor generates five single-chain PIs and a remarkable two-chain inhibitor formed by disulfide-bond Linkage of Nand C-terminal peptide fragments. Surprisingly, PI precursors adopt this circular structure regardless of the number of inhibitor domains, suggesting this bracelet-like conformation is characteristic of the widespread potato inhibitor II (Pot II) protein family.

A Study of the Corporative Portals as a Tool of Explicit Knowledge Externalization in Universities

The corporative portals, enabled by Information Technology and Communication tools, provide the integration of heterogeneous data proceeding from internal information systems, which are available for access and sharing of the interested community. They can be considered an important instrument of explicit knowledge evaluation in the. organization, once they allow faster and,safer, information exchanges, enabling a healthful collaborative environment. In the specific case of major Brazilian universities, the corporate portals assume a basic aspect; therefore they offer an enormous variety and amount of information and knowledge, due to the multiplicity of their activities This. study aims to point out important aspects of the explicit knowledge expressed by the searched universities; by the analysis, of the content offered in their corporative portals` This is an exploratory study made through, direct observation of the existing contents in the corporative portals of two public universities as. Well as three private ones. A. comparative analysis of the existing contents in these portals was carried through;. it can be useful to evaluate its use as factor of optimization of the generated explicit knowledge in the university. As results, the existence of important differences, could be verified in the composition and in the content of the corporative portals of the public universities compared to the private institutions. The main differences are about the kind of services and the destination-of the,information that have as focus different public-target. It-could also be concluded that the searched private universities, focus, on the processes related to the attendance of the students, the support for the courses as well as the spreading of information to the public interested in joining the institution; whereas the anal public universities prioritize more specific information, directed to,the dissemination-of the research, developed internally or with institutional objectives.

The perception of Executives and other Employees on the answer to the Sarbanes-Oxley: case study of a subsidary of the American auto industry established in Brazil

To attend and obtain the systems and. internal controls mechanisms proposed by Sarbanes-Oxley certifications is actually a big challenge,for most of the multinational companies registered in SEC (US Securities and Exchange Commission). This work has the objective of contributing to the analysis of this methodology, not only to attend the law but to reduce cost and generate value through the strengthen of the internal control systems, turning them into animating value generation process mechanisms. So, the idea is to identify the main gaps in the theory through the literature revision and a case study in order to put a question to the main deficiencies, strong points or contributions through the evaluation of the noticed practices. Finally, we can say that a a result of the research and the analyses made in. this case, the vast majority of executives and other employees recognize the benefit that Sarbanes-Oxley Act has brought to the company searched. Also recognize that, although there is still necessity for systemic adequacy and infrastructure, it helps and reinforce reducing and controlling the risks. the system of internal controls in all areas of expertise. They approach and understand that there is the need for a change in the other employees` culture to be inserted in the day-today routine as internal controls, attention to Sarbanes-Oxley and Corporate Governance, making the control cost smaller when compared to the benefits generated.

Customer Perception about Loyalty Programs in Agricultural Market: a case study

This study discusses the use of loyalty programs and Customer perception in, agricultural market. The theoretical review includes relationship marketing, its objectives, dimensions and instruments, and loyalty programs. The method for the empirical part consisted on qualitative research, through a case study conducted at one of the largest crop protection chemical companies in Brazil. The case is representative once this company was pioneer in its segment in adopting the customer relationship management. (CRM) approach to-their clients: It has been a consensus that customer relationship is a tool to amplify the Customer share. This.,is so, due the. increasing competition generated by the entrance of generic products and the retaliation actions adopted by the multinational groups. The case study includes a market overview, a description of the company, its loyalty program, the image of the program from the customer`s perspective, and the main results acquired with the CRM program. The Study also presents some recommendations for-companies that are pursuing strategies to. increase their customer share through loyalty programs.

The Adequacy of the Enterprise Resources Planning (ERP) Systems for the Creation of intangible Managerial Accounting Information: an exploratory study

The general objective of this work was to study the contribution of the ERP for the quality of the managerial accounting information, through the perception of managers of large sized Brazilian companies. The initial principle was that, presently, we live in an enterprise reality characterized by global and competitive worldwide scenery where the information about the enterprise performance and the evaluation of the intangible assets are necessary conditions for the survival, of the companies. The research of the exploratory type is based on a sample of 37 managers of large sized-Brazilian companies. The analysis of the data treated by means of the qualitative method showed that the great majority of the companies of the sample (86%) possess an ERP implanted. It also showed that this system is used in combination with other applicative software. The managers, in its majority, were also satisfied with the information generated in relation to the dimensions Time and Content. However, with regard to the qualitative nature of the information, the ERP made some analysis possible when the Balanced Scorecard was adopted, but information able to provide an estimate of the investments carried through in the intangible assets was not obtained. These results Suggest that in these companies ERP systems are not adequate to support strategic decisions.

The sound field generated by tethered stingless bees (Melipona scutellaris): inferences on its potential as a recruitment mechanism inside the hive

In stingless bees, recruitment of hive bees to food sources involves thoracic vibrations by foragers during trophallaxis. The temporal pattern of these vibrations correlates with the sugar concentration of the collected food. One possible pathway for transfering such information to nestmates is through airborne sound. In the present study, we investigated the transformation of thoracic vibrations into air particle velocity, sound pressure, and jet airflows in the stingless bee Melipona scutellaris. Whereas particle velocity and sound pressure were found all around and above vibrating individuals, there was no evidence for a jet airflow as with honey bees. The largest particle velocities were measured 5 mm above the wings (16.0 +/- 4.8 mm s(-1)). Around a vibrating individual, we found maximum particle velocities of 8.6 +/- 3.0 mm s(-1) (horizontal particle velocity) in front of the bee`s head and of 6.0 +/- 2.1 mm s(-1) (vertical particle velocity) behind its wings. Wing oscillations, which are mainly responsible for air particle movements in honey bees, significantly contributed to vertically oriented particle oscillations only close to the abdomen in M. scutellaris(distances <= 5 mm). Almost 80% of the hive bees attending trophallactic food transfers stayed within a range of 5 mm from the vibrating foragers. It remains to be shown, however, whether air particle velocity alone is strong enough to be detected by Johnston`s organ of the bee antenna. Taking the physiological properties of the honey bee`s Johnston`s organ as the reference, M. scutellaris hive bees are able to detect the forager vibrations through particle movements at distances of up to 2 cm.

Accumulation and Gaps in the Research on Argentine Rock

Based on a comprehensive study in research centers and libraries, a panorama of the critical response to Argentine rock in academic circles has been traced in various fields of knowledge. Research works including books, trade magazines, and academic papers on this musical movement spanning four decades have been consulted. The results show that the criticism has generated a ""developing tradition"" around the movement, mainly in the Social and Communication Sciences, and it has presented the following predominant traits: approaching rock essentially as a determinant of ""social identities""; periodization in the genre according to political regime: and analysis of the lyrics based solely on content. These traits contribute to a delimitation of rock as an exclusive phenomenon of the mass media, which relegates to secondary importance its aesthetic function and its relationship with other artistic series. Furthermore, we have observed a scarcity of approaches to rock lyrics as a linguistic-discursive surface.

Ventilation Patterns Influence Airway Secretion Movement

BACKGROUND: Retention of airway secretions is a common and serious problem in ventilated patients. Treating or avoiding secretion retention with mucus thinning, patient-positioning, airway suctioning, or chest or airway vibration or percussion may provide short-term benefit. METHODS: In a series of laboratory experiments with a test-lung system we examined the role of ventilator settings and lung-impedance on secretion retention and expulsion. Known quantities of a synthetic dye-stained mucus simulant with clinically relevant properties were injected into a transparent tube the diameter of an adult trachea and exposed to various mechanical-ventilation conditions. Mucus-simulant movement was measured with a photodensitometric technique and examined with image-analysis software. We tested 2 mucus-simulant viscosities and various peak flows, inspiratory/ expiratory flow ratios, intrinsic positive end-expiratory pressures, ventilation waveforms, and impedance values. RESULTS: Ventilator settings that produced flow bias had a major effect on mucus movement. Expiratory How bias associated with intrinsic positive end-expiratory pressure generated by elevated minute ventilation moved mucus toward the airway opening, whereas intrinsic positive end-expiratory pressure generated by increased airway resistance moved the mucus toward the lungs. Inter-lung transfer of mucus simulant occurred rapidly across the ""carinal divider"" between interconnected test lungs set to radically different compliances; the mucus moved out of the low-compliance lung and into the high-compliance lung. CONCLUSIONS: The movement of mucus simulant was influenced by the ventilation pattern and lung impedance. Flow bias obtained with ventilator settings may clear or embed mucus during mechanical ventilation.