bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibration and Control of Axially Moving Belt System: Analysis and Experiment by Parametric Excitation
Authors: Okubo H. , Takano K. , Matsushita O. , Watanabe K. , Hirase Y.
Published: March 2007

High-speed operation is required for industrial machines equipped with belt driving systems. The belt is, however, subject to a speed limitation barrier due to the occurrence of bending mode vibration reso nances caused by machinery error, for example, pulley eccentricity. To combat these resonances of the linear system, the parametric excitation method providing the belt tension fluctuation is proposed through the con cept of the open-loop vibration control theory. This analysis considers two types of fluctuation excitation featured by the frequency synchronized with one or two times the pulley revolution. In this paper, the math ematical model is analyzed by using the equation of motion of the forced vibration including the parametric excitation. We apply this method to the belt system and test the validity of it through experimentation.
Nonlinear Dynamics of a Boom Crane
Authors: Chin C. , Nayfeh A.H. , Abdel-Rahman E.
Published: March 2007

We study a boom crane modeled as a spherical pendulum undergoing base excitations. We demon strate how instabilities in the payload motion arise due to a combination of a one-to-one internal resonance and a primary (additive) resonance or a parametric (multiplicative) resonance. The method of multiple scales is used to derive four nonlinear ordinary-differential equations describing the amplitudes and phases of the in-plane and out-of-plane modes. The modulation equations are used to study the equilibrium and dynamic solutions and their stability. The response could be a single-mode (planar) or a two-mode (three-dimensional) motion. We also study the limit cycles arising in the response and ascertain their stability Numerical re sults indicate the existence of a sequence of period-doubling bifurcations that culminates in chaos, multiple attractors, intermittency of type I, and cyclic-fold bifurcations.
The Fluttering Panel as a Continuous Nonlinear Nonconservative System
Authors: Bolotin V.V. , Grishko A.A. , Roberts J.B. , Kounadis A.N. , Gantes CH
Published: March 2007

A nonlinear continuous elastic system subjected to a combination of conservative and nonconserv ative forces is considered where parameters controlling the system are moving deep in the instability domain. New techniques are employed to present the numerical results in a compact form suitable for the interpreta tion of the system postcritical behavior. As an example, an initially planar elastic rectangular panel subjected to supersonic gas flow and loaded in the middle surface by "dead" forces is considered. Classical plate theory and piston theory approximation are used to simplify the statement and analysis of the problem. The steady states of the systems and their stability are analyzed without discretization of the problem, that is, within the framework of continuum solid mechanics. When dynamic behavior is concerned, the study is performed for a finite-degree-of-freedom approximation of the system. However, the number of degrees of freedom is cho sen to be high enough to address the main features of the continuous system, and the final numerical results are discussed in terms of continuum systems. A variety of attractors is found in remote postcritical domains, and the high sensitivity of the system behavior to the variation of the control parameters and initial conditions is demonstrated.
Suboptimal Bilinear Control Methods Applied to Suppressing Car Vibrations
Authors: Elbeheiry Elsayed M.
Published: March 2007

Methods for suboptimal bilinear control of semiactive, smart damping elements are developed in this study by use of extensions of linear-quadratic optimal control. These damping elements are considered in the form of continuously variable dampers, which are capable of adapting their damping forces to reasonably match full- or limited-state control (inputs) forces generated by broadband actuators. During the operation of these dampers, simultaneous broadband force generators control some other locations in the vibratory system. This leads to a class of bilinear vibratory systems with disjunct (active) linear and (semiactive) multiplicative control inputs. Generally, these disjunct control inputs might be contributing to control the same vibratory modes or not. A generalized quadratic performance index is considered for minimizing variances of the system state variables, the broadband control forces, and the damping factors of semiactive dampers. This performance index is constrained by (i) the inability to measure all the system state variables that are necessary for the operation of the broadband control input and (ii) the necessity to consider the switching states of the semiactive damping elements. Methods for full-state bilinear control and limited-state bilinear control are first derived. Then an application is made to an in-plane 4-DOF car model of front suspension unit having semiactive damper and rear suspension unit having broadband ideal actuator, or vice versa, as two different suspension schemes. Time-domain simulation of the vehicle response to (a hole followed by a bump) deterministic and stochastic road inputs is made. Comparisons with full-state control and limited-state control designs show the effectiveness of the bilinear control configurations derived in this work.
A Class of Novel Space Platform-Based Manipulators With Slewing and Deployable Links: Analyses and Experiments
Authors: Modi V.J. , Cao Y. , De Silva C.W. , Misra A.K.
Published: March 2007

This paper studies dynamics of a space platform—based mobile two-module manipulator with each module consisting of two links, one free to slew (revolute joint) and the other permitted to deploy and retrieve (prismatic joint). Both the platform and the manipulator are considered flexible. Using the computation ally efficient order- N Lagrangian formulation of the system, the paper presents results of a comprehensive parametric study aimed at assessing effects of initial conditions, system variables, and manipulator maneu vers on the uncontrolled response. In general, the mass of payload, speed of maneuver, and joint flexibility represent three important parameters governing the system dynamics. Results suggest significant coupling between the platform, link, and joint vibrations as well as the system libration. The system exhibited unac ceptable response under critical combinations of parameters, thus indicating a need for active control. Next, effectiveness of a composite control strategy, involving the feedback linearization technique (FLT) applied to the rigid degrees of freedom with flexible generalized coordinates regulated through the linear quadratic regulator, is assessed. The control procedure proves to be remarkably successful in damping even relatively large disturbances in a robust fashion. Finally, the numerical simulation results are complemented with the prescribed trajectory tracking data, obtained using a two-module (four links) ground-based prototype manip ulator in conjunction with the FLT and proportional integral derivative control. Considering the presence of friction and backlash at the joints, the tracking results may be considered satisfactory. The comprehensive study lays a sound foundation for the design of this class of novel manipulators.
A Higher-Order Theory for Vibration Analysis of Curvilinear Thick Shallow Shells with Constrained Boundaries
Authors: Liew K.M. , Lim C.W.
Published: March 2007

This article presents the vibration analysis of thick doubly curved shallow shells having curvilinear planform. The Gaussian curvature of shell varies from positive (such as spherical) to negative (such as hyperbolic paraboloidal). The boundaries are constrained with either soft-simply supported or fully clamped edges. A higher-order shear deformation theory, which includes transverse shear strain and rotary inertia, is developed to model the vibration characteristics of the shell. The inclusion of Lamé parameters in the present formulation accounts for the presence of shell curvature and yields cubic transverse shear strain distribution in contrast with the existing quadratic expressions. A set of versatile, globally continuous shape functions is adopted in the Ritz numerical procedure to approximate the displacement and rotation fields. A set of new results for a wide range of shell configurations is presented with some selected contour and three-dimensional displacement mode shapes.
Three-Dimensional Vibrations of Truncated Hollow Cones
Authors: Leissa Arthur W. , So Jinyoung
Published: March 2007

This work presents a three-dimensional (3-D) method of analysis for determining the free vibration frequencies and corresponding mode shapes of truncated hollow cones of arbitrary thickness and having arbitrary boundary conditions. It also supplies the first known numerical results from 3-D analysis for such problems. The analysis is based upon the Ritz method. The vibration modes are separated into their Fourier components in terms of the circumferential coordinate. For each Fourier component, displacements are expressed as algebraic polynomials in the thickness and slant length coordinates. These polynomials satisfy the geometric boundary conditions exactly. Because the displacement functions are mathematically complete, upper bound values of the vibration frequencies are obtained that are as close to the exact values as desired. This convergence is demonstrated for a representative truncated hollow cone configuration where six-digit exactitude in the frequencies is achieved. The method is then used to obtain accurate and extensive frequencies for two sets of completely free, truncated hollow cones, one set consisting of thick conical shells and the other being tori having square-generating cross sections. Frequencies are presented for combinations of two values of apex angles and two values of inner hole radius ratios for each set of problems.
A Brief Discussion on Some Dynamic Energy Principles
Authors: Filipich Carlos P. , Rosales Marta B.
Published: March 2007

An energy principle to find the equations of motion is outlined within the scope of continuum classical mechanics and compared with the very useful and widely applied Hamilton's Principle. It is shown that to obtain convenient results by means of the latter principle, a strong restriction on the variations of the functions of interest must be accepted. Furthermore, such restrictions are confronted with the ones that, at the same time, derive from the manipulation of the principle herein proposed. Two illustrative examples are also included.
Pole-Zero Assignment of Vibratory Systems by State Feedback Control
Authors: Ram Yitshak M.
Published: March 2007

Analysis and design of vibratory systems sometimes require assigning poles and zeros of a fre quency response function. Pole assignment is usually needed to avoid harmonic excitation near resonance frequencies. Assigning some zeros appropriately may eliminate, or absorb, particular components of the vibration response. This article presents a pole-zero assignment problem and its motivation. A method that assigns the poles and zeros of a certain frequency response function is given. This is achieved by determining both the position and control function of the state feedback control.
Robust Stabilization of Flexible Mechanical Systems Under Noise Uncertainties and Time-Varying Parameter Perturbations
Authors: Chou Jyh-Horng , Chen Shinn-Horng , Chao Chien-Hsiang
Published: March 2007

This article presents a new time domain approach to treat the active stabilization (active vibration control) problem of flexible mechanical systems under (1) mode truncation, (2) nonlinear/linear time- varying parameter perturbations, (3) noise (input noise and measurement noise), and (4) noise uncertainties. In the proposed approach, the residual model is viewed as an additive perturbation to the controlled dynamics. A new robust stability condition is derived for the flexible mechanical system that is controlled by a linear-quadratic-Gaussian (LQG)-based controller and subject to mode truncation, noise uncertainties, and nonlinear/linear time-varying parameter perturbations. The proposed new condition gives an insight into the relationship between the stability margins of the controlled and residual mode subsystems, spillover effect, and additive time-varying parameter perturbations. Finally, two examples are given to confirm the presented approach.
Inverse Iteration for Large Defective Eigensystems
Authors: Leung A.Y.T. , Chan J.K.W. , Chan C.W.
Published: March 2007

The solutions of large eigensystems having cluster, multiple, or defective eigenvalues by inverse iteration using one trial vector at a time are of interest. The Rayleigh quotient is used as shift. New formulas for each particular case are derived for definite convergence. Six numerical examples, including three-multiple defective eigenvalues, are given.
Free Flexural Vibration Analysis of Arbitrary Plates With Arbitrary Stiffeners
Authors: Barik Manoranjan , Mukhopadhyay Madhujit
Published: March 2007

Isoparametric element tends to lock in shear for very thin plates. Though numerical techniques such as reduced-integration or selective reduced-integration are used to avoid this effect, they do not necessarily guarantee the solution to the problem, even if they increase notably the possibility of convergence with the exact solution. In the present formulation, a new four-noded stiffened-plate bending element, having the elegance of the isoparametric element to model the arbitrary shape of the plate but without any numerical disturbing feature like shear-locking problem, is presented. Another unique feature is the arbitrary placement of the stiffener inside the plate element without any restriction of its orientation. Stiffened plates having various shapes, boundary conditions, and disposition of stiffeners are analyzed and compared with available results in the literature wherever possible.
Reduced-Order Controller of Transverse-Torsional Coupled Vibration Based on Linear Matrix Inequalities
Authors: Saragih Roberd , Yoshida Kazuo
Published: March 2007

This paper is concerned with the application of reduced-order controller to a flexible structure hav ing the transverse-torsional coupled vibration modes. The dynamical model of the structure is first presented and then the robust controller for the structure is designed by using the H∞-control theory. Furthermore, the order of the controller is reduced by using the combination of the alternating-projection method and the weighted-balanced realization. The performance of the reduced-order controller is examined through simu lation and experiment. To verify its robustness and validation in the transverse-torsional coupled vibration condition, the lumped mass is added on the right side at the 3rd story. From these results, it is made clear that the reduced-order controller obtained by the proposed method is effective in reducing the vibration of the structure, where the order of the controller can be reduced to 8th order from 30th order.
Emerging Applications of Newer Antipsychotic Agents in Specific Patient Populations
Authors: Littrell Kimberly H. , Littrell Steven H.
Published: March 2007

Conventional neuroleptics have been the mainstay of treatment for patients with schizo phrenia for many years. The mechanism of action of these drugs has long been accept ed and their side effects well documented. With the recent introduction of newer antipsy chotics such as clozapine, risperidone, and olanzapine, a new generation of medications has become available whose pharmacologic properties are just beginning to be realized. These newer antipsychotics appear to be superior to conventional neuroleptics in treat ing patients with schizophrenia. Because of their reduced neurotoxicity, the newer antipsychotics may be particularly beneficial in treating psychosis in specific putient populations. This review presents preliminary findings on the use of the newer antipsy chotics for treating psychosis in five patient populations: children and adolescents with schizophrenia and other psychotic disorders; first-episode schizophrenia; dual diagno sis ; bipolar disorder; and elderly patients. Because of the expanded utilities of the newer antipsychotics, psychiatric nurses should be familiar with all available treatment options. (J Am Psychiatr Nurses Assoc [1998]. 4, S42-S52.)
Working in Groups: identification and Treatment of Students' Perceived Weaknesses
Authors: Schullery Nancy M. , Gibson Melissa K.
Published: March 2007

The ability to work in groups is vital for today's workforce, yet the existence of the necessary skills among students is questionable. Although group activities are now common, specific classroom instruction in effective group participation skills is not. Moreover, students recognize the need for such instruction. Content analysis of students' self-descriptions identified ten categories of deficiencies: conflict avoidant, public speaking anxiety, leadership, shy, oral skills, lack motivation, brainstorm ing, impatient,-intolerant, dislike groups. These weaknesses were addressed by a vuriety of pedagogical exercises including individual presentations, type or tem perament identification, an enhanced understanding of argument and brainstorm ing, and ways to encourage substuntive, but not procedural or affective, conflict. Student-perceived improvements were found in all categories, with the largest improvement in public speaking anxiety.
Inbox Shock: A Study of Electronic Message Volume in a Distance Managerial Communication Course
Authors: Hartman Jackie , Lewis Jeffrey S. , Powell Karen Sterkel
Published: March 2007

As institutions of higher education strive to serve students who are diverse and geographically dispersed, many of them are implementing distance education pro grams using technology-mediated communication. Research reveals that distance education is often as effective as traditional education; however, teachers and stu dents are confronted with a variety of obstacles. Thus educators need to determine the most effective and efficient methods of communicating with distance students. An examination of e-mail messages sent to the instructor of an MBA class by dis tance students reveals that the volume of messages sent depends on students' tech nology proficiency, ability to process and seek out information, topic affinity, and relational needs. Furthermore, the findings reveal that an instructor can decrease the volume of messages received by researching the student population, communi cating proactively, and taking advantage of the messaging system's tools.
Managing Communication within Virtual Intercultural Teams
Authors: Grosse Christine Uber
Published: March 2007

As global companies increasingly rely on virtual teams to conduct short- and long- term projects, business students need to be prepared to manage the communication of intercultural teams. Communicating across cultures using technology can be a difficult task. It requires understanding the advantages and limitations of technol ogy and how to build relationships via technology. Virtual team members need to choose an appropriate communication channel for their purposes and be sure to balance distance work with face-to-face communication. Team leaders should encourage open communication and brainstorming, and avoid assignment of blame. Other strategies for success include: 1) develop a network of good relation ships built on trust and understanding, 2) show respect for other cultures and lan guages, and 3) understand how diversity strengthens the team.
Bad Writing Can Be Good Business
Authors: Butenhoff Carla
Published: March 2007

Carla Butenhoff has to practice what she preaches. She has Master's Degrees in communications fields from Cornell University and the University of Wisconsin—Milwaukee, and has taught in several colleges. For the past four years, she has been a spokesman for a large Midwest company. Her remarks were made at the ABCA Midwest Regional Conference, April 22, 1977, in Milwaukee.
A Guide to Using Color Effectively in Business Communication
Authors: Jones Scott L.
Published: March 2007

As colorprinters drop in price, business communicators will have an increas ing ability to use color. Judicious use of color can make documents attractive, professional, and effective. Unfortunately, poorly used color can seriously detractfrom a document. To prevent such problems, this essay introduces busi ness communication instructors to the principles of effectively using color. Among topics discussed are general uses of color, color used with text, spot color, color in oral presentations, and color in résumés.
An Exploration of Gender Bias in Computer Clip Art
Authors: Dyrud Marilyn A.
Published: March 2007

A growing body of literature presenting the results of research regarding text book illustrations indicates that visual gender bias is obvious in several acade mic fields, including business communication. To date, however, no study has extended those observations to clip art files in popular computer programs. The current study examines over 14,000 clip art images for gender bias from six different Windows-based programs: WordPerfect Presentations, PowerPoint 4.0, Microsoft Publisher 2.0, Harvard Graphics 3.0, Power Up!, and Corel 3.0, CD-ROM. Tabulations indicate that only 4.54% of total images depict women and that they are typically presented in stereotypical roles, such as secretaries, nurses, teachers. Reasons include a male bias in the computer science field (a 3:1 ratio in programming), apparent gender-based differences in relationships with machines, and a societal gap in traruitioning between old and new media.
An International Course in International Business Writing: Belgium, Finland, the United States
Authors: Connor Ulla M. , Davis Kenneth W. , De Rycker Teun , Phillips Elisabeth Margaretha , Verckens J. Piet
Published: March 2007

Since 1994, a course in international business writing has been taught simul taneously at institutions in Belgium, Finland, and the United States. The course, which grew out of earlier, shorter-term activities involving Belgian and U.S. students, has three components: (a) instruction; (b) a simulation, in which students exchange business documents internationally; and (c) case studies of business people who communicate internationally in writing.
Designing a Problem-Based Learning Environment for ESL Students in Business Communication
Authors: Allen Roberta , Rooney Pam
Published: March 2007

As the population of students speaking English as a second language increases, our business communication courses have required changes in both content and pedagogical approach. We have taught writing, speaking, and lis teningfrom a problem-solving perspective for many years and now find its emphasis on critical thinking poses different challenges for the ESL students in our courses. Consequently, we have designed a problem-based course struc ture for an upper-level business communication course that allows both ESL and native English-speaking students the opportunity to improve communica tion abilities in cross-cultural work groups.
Meeting Technology: From Low-Tech to High-Tech
Authors: Munter Mary
Published: March 2007

This article describes a series of low-tech and high-tech options for use in meeting management and summarizes the advantages and disadvantages of each. These options include (1) face-to-face meetings, with choices of flipcharts, non-electronic boards, electronic boards, handouts, still projectors, and multimedia projectors; and (2) groupware meetings, with choices of audio- and videoteleconferencing, e-mail meetings, and electronic meetings.
Multimedia Copyright Laws and Guidelines: Take the Test
Authors: Arn Joseph V. , Gatlin Rebecca , Kordsmeier William
Published: March 2007

Increasing numbers of Association for Business Communication members are using multimedia as a form of instruction. Because copyright guidelines affecting multimedia production have only recently been established, policies are not well known. To determine if ABC members understand the guidelines, we created a questionnaire about specific instances of multimedia use and sent it via Internet e-mail to a sample chosen from the 1996 membership directory. Respondents received an average grade of "C," with most answering conservatively, assuming that copyright restrictions are more restrictive than they, in fact, are.
Case Method Instruction in the Business Writing Classroom
Authors: Dorn Elizabeth M.
Published: March 2007

An effective pedagogy narrows or closes the gap between what is taught in pre- professional communications programs and what is expected on the job. Case studies are often an important element in such pedagogy. But an analysis of cases recently published in Business Communication Quarterly and a survey of 25 employees who consider writing important to successful performance at work show that we may be giving our students instruction they will rarely use. The BCQ cases typically require students to respond to exceptional rhetorical situations when in reality the rhetorical situations writers usually face require more mundane and standardized types of discourse.
Writing Apprehension in Beginning Accounting Majors
Authors: Faris Kay A. , Golen steven P. , Lynch David H.
Published: March 2007

With writing skills receiving increased emphasis in the accounting curriculum, edu cators need to explore the potential barriers to writing that students may experience. The primary purpose of this study was to determine whether accounting majors have higher levels of writing apprehension than students in other majors. Also stud ied was whether gender, age, and grades in Freshman Composition were related to the level of writing anxiety. A sample of students responded to items on the Writing Apprehension Test to measure their writing apprehension. The students also identi fied their gender, age, major, and grades in Freshman Composition.

Significant differences do exist in level of writing apprehension based on grades in Freshman Composition but not based on a student's age or gender choice. Most important, accounting majors did show significantly greater appre hension than non-accounting majors.
Note. Physical parameters in controlling saffron quality / Nota. Algunos parámetros físicos del control de calidad del azafrán
Authors: Alonso G.L. , Salinas M.R. , Sánchez-Fernández M.A. , Garijo J.
Published: March 2007

This study involved 270 samples of saffron from Spain and other leading producers (Greece, India, Iran, Italy and Morocco). The Spanish samples were obtained directly from the producers while the foreign samples were acquired with the guarantee of their origin and lack of adulteration. The tradi tional physical parameters indicated in quality regulations were analyzed and ranges were estab lished for each one (style length, stigma length, stigma percentage, moisture content at 40 and 103 °C, percentage of volatile matter and percentage of ash). The terms 'total filament', 'mass' and 'stigma mass' are proposed as being more specific than the simple term 'mass' which is used in the quality regulations; the parameter lineal filament density is also defined. The saffron grown in the provinces of Cuenca and Albacete (Castilla-La Mancha region, Spain) showed the highest percentage of stigma length. The lower stigma mass of Spanish saffrons compared with saffron from other countries indi cated that more flowers are necessary to obtain the same weight of spice. The highest values of the percentage of volatile matter were obtained in Iranian and Spanish saffrons. A greater range of ash percentage than indicated in the quality regulations was obtained.
Note. Physiological changes in bananas subjected to automodified atmosphere / Nota. Cambios fisiológicos de plátanos envasados en atmósfera modificada
Authors: Tovar B. , Mata M. , García H.S.
Published: March 2007

Physiological changes during the ripening of whole and peeled bananas stored in chambers with automodified atmospheres were evaluated. Calcium carbide was applied to preclimacteric bananas for ripening initiation. Three different lots were placed into glass containers, which were maintained at 20 ± 0.5 °C. The treatments evaluated were: peeled bananas inside the glass container, whole (unpeeled) bananas inside the glass containers, and control, unpeeled bananas outside the chambers. Peeling of firm green fruits did not induce spoilage nor interfere with the normal ripening of the bananas when they were kept inside the automodified atmosphere. Under this storage, peeled ba nanas showed better qualities than whole bananas. The ripeness of peeled bananas in automodified atmospheres was similar to that of control fruits.
Influence of enzymes in sourdough wheat breadmaking. Changes in pentosans / Influencia de las enzimas y los iniciadores microbianos en panificación. Cambios en las pentosanas
Authors: Martínez-Anaya M.A. , Devesa A.
Published: March 2007

The effect of the joint use of sourdough and enzymes in breadmaking on total, soluble and insoluble pentosans, and composition of water extractable pentosans was studied. Two wheat flours of differ ent baking quality, two commercial starters (a pure strain of Lactobacillus sanfranciscensis and the multiform starter Böcker) and two commercial enzymes (pentosanase/amylase, lipase, and their com bination) were included in the study. The presence of sourdough starters modified the amount of water extractable pentosans, promoting a solubilization at the dough stage and insolublization dur ing baking, as well as a greater degree of arabinose substitution. Flour and enzymes interacted along the different stages of the process. The pentosanase/amylase increased extractability of pentosans depending on the endogenous pentosan structure of either flour. Both flours showed different degrees of arabinose substitution, which was modified by enyzme treatment, mainly during baking.
Revisión: Irradiación de alimentos.—aspectos generales/Review: Food irradiation.—General aspects
Authors: Sendra E. , Capellas M. , Guamis B. , Felipe X. , Mor-Mur M. , Pla R.
Published: March 2007

Irradiation has been proposed for disinfestation, inhibition of sprouting, destruction of parasites in meat and fish, to delay maturation of fruit and pasteurization and sterilization. In some applications it could replace or supplement chemical preservatives; in other cases it may have unique advantages (dry or frozen foods). Generalizations about effects of irradiation may be misleading if the dose and commodities are not specified. Radioactivity cannot be induced in foods by treatment with approved sources. Toxicological and nutritional evaluation has confirmed the safety of irradiated foods at doses below 10 KGy. Food irradiation is limited by organoleptical changes; irradiation in the absence of oxygen and at the frozen state could reduce undesirable changes. Food irradiation is not a panacea for all food preservation; it cannot replace proper food sanitation, packaging, storage and preparation. The public and political debate of whether or not irradiation of foods should be permitted in the European Community has become a confused dialogue about the real consequences of food irradiation. Owing to the timeliness of the question, it is important to present and discuss the results of this research.
Biotoxinas marinas: intoxicaciones por el consumo de moluscos bivalvos/Seafood toxins: poisoning by bivalve consumption
Authors: Martín R. , García T. , Sanz B. , Hernández P.E.
Published: March 2007

Seafood toxins are becoming increasingly important as etiologic agents of foodborne diseases around the world. This is partly because of greater awareness of the potential problems of the paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), diarrheic shellfish poisoning (DSP) and more recently, a new type of seafood toxicity, called amnesic shellfish poisoning (ASP). This review describes the molluskan shellfish and biotoxins implicated, the development of standardized methods for detecting and quantifying these toxins, the importance of the economic loss resulting from their presence and the establishment of regular chemical monitoring for marine toxins.
Efecto crioprotector de maltodextrinas en surimi de jurel (Trachurus murphyi)/Cryoprotective effect of maltodextrins on surimi from jack mackerel (Trachurus murphyi)
Authors: Dondero M. , Sepúlveda C. , Curotto E.
Published: March 2007

This research evaluated the cryoprotective effects of 18, 20, 25 and 36 DE (dextrose equivalent) maltodextrins at 8% w/w in surimi from jack mackerel stored at -18 "C for 27 weeks. The results were compared with a commercial mixture (8% sucrose/sorbitol 1:1) and with a control without cryoprotectants. Protein denaturation decreased during frozen storage for all samples tested when compared with the control. Maltodextrins 20 and 25 DE as well as sucrose/sorbitol mixture were the most effective in stabilizing surimi proteins during frozen storage. Myosin peaks enthalpy for surimi with 20 and 25 DE maltodextrins was maintained at the same level as the commercial mixture and significantly higher than that for the control ( p << 0.01). Enthalpy for the actin tran sition was not found to vary significantly with treatments or storage time.
Review: Biochemical and technological assessment of the metabolism of pure and mixed cultures of yeast and lactic acid bacteria in breadmaking applications / Revisión: Aspectos bioquímicos y tecnológicos del metabolismo de cultivos puros y mixtos de levaduras y bacterias ácido lácticas en panificación
Authors: Collar C.
Published: March 2007

The production of varieties of breads with the quality required at present by the European consumer closely relates to the proper use of starting microorganisms in controlled and optimized breadmaking conditions. The relationship between processing requirements and wheat bread quality involves an understanding of the metabolism of the starting microflora which regulate production or assimilation of suitable and unsuitable metabolites during the breadmaking process, mediated by the specific enzyme activities and nutritional requirements of yeast and lactic acid bacteria. In this paper, recent advances in the biochemical and technological assessment of pure and mixed cultures of yeast and lactic acid bacteria in breadmaking applications are reviewed. Metabolite profiles in model and simplified wheat flour systems, performance of breadmaking starters in straight and sourdough systems, and relationships between process conditions, tech nological performance and metabolism of fermentation starters are discussed.
Production of RNA derivatives by Kluyveromyces fragilis grown on whey Producción de derivados de RNA mediante Kluyveromyces fragilis inoculada en suero de queso
Authors: Belem M.A.F. , Lee B.H.
Published: March 2007

Aerobic fermentation of cheese whey by Kluyveromyces fragilis has been proposed as a means of reducing its pollution potential and of producing ribonucleotide derivatives. 5'-Ribonucleotides, such as 5'-GMP and 5'-IMP are high added-value products that are used as flavour enhancers in foods. 5'-Ribonucleotide derivatives, nucleosides, nucleoside analogues and free bases are known to have anti-tumour, anti-viral and probiotic effects. In this study, K. fragilis was grown in a medium containing dehydrated whey under aeration. After different times of fermentation (24, 48, 72 h) aliquots of cells were autolysed either by incubation at three different fixed temperatures (48, 50, 53 °C) for 48 h or by incubation through a temperature gradient (45-65 °C, increasing by 5 °C every 5 h). Autolysed cells were centrifuged and the supernatant was analysed by high perfor mance liquid chromatograpy. High concentrations of free bases (0.74%) and 3'-nucleotides (0.64%) on the basis of biomass (d.w.) were obtained by a specified autolysis condition (50 °C, pH 7.5, 48 h), but less than 0.1% of 5'-nucleotides were obtained. Autolytic enzymes were able to break the yeast cells and hydrolyse the molecules of RNA into compounds that have therapeutic effects (free bases), but were not able to transform them into 5'-GMP and 5'-IMP.
Influence of process variables on the hydrolysis of shark muscle protein / Influencia de las variables de proceso en la hidrólisis de proteína del músculo de tiburón
Authors: Mendonça Diniz F. , Martin A.M.
Published: March 2007

Muscle tissue from the spiny dogfish ( Squalus acanthias) was enzymatically hydrolysed using a bacterial endopeptidase. The influence of the process variables (temperature, pH, enzyme/ substrate ratio and reaction time) was investigated with regards to the extent of proteolytic degra dation and the recovery of soluble nitrogen from the substrate. Maximum significant nitrogen recovery (NR) was found to be 76.2%, in a 2 h proteolytic reaction. Optimum conditions were 55 °C, pH 8.0 and an enzyme/substrate ratio of 40 mg enzyme/g minced shark muscle (wet weight basis). Under these conditions, a degree of hydrolysis (DH) of 18.6% was obtained. A linear corre lation ( R2 = 0.99) was found to exist between the two measured parameters, NR and DH.
Optimización del escaldado de calabacita criolla (Cucurbita pepo) deshidratada a temperaturas bajas y tiempos largos / Optimization of stepwise blanching of dehydrated zucchini (Cucurbita pepo)
Authors: Quintero-Ramos A. , Sánchez de la Paz A.L. , Meza-Velázquez J.A. , Jiménez J.A. , Barbosa-Cánovas G. , Anzaldúa-Morales A.
Published: March 2007

Low-temperature prolonged blanching was applied to sliced zucchini prior to dehydration. Treatment was optimized by a response surface method. The variables studied were: blanching temperature (50, 55, 65, 75 and 79 °C) and blanching time (23, 79, 30, 45, 60, 66 min). Color, texture (cutting force) and rehydration rate of the product were also evaluated. The optimum conditions for the texture, color (parameter b*) and rehydration rate (RR) of the pretreatment were: temper ature, 61-66 °C for 52-56 min. The prediction model was applied with these conditions and the following values were obtained: rehydration rate 5.14, texture 28.82 Newtons and the color para meter b' (blue-yellow) 34.0. The prediction models for maximum cutting force and parameter b* showed a significant fit ( p ≤ 0.05) of the experimental values and the prediction model for the RR showed a lack of fit ( p ≤ 0.05) whereas the parameters L* and a* were not affected significantly. These optimum conditions were verified experimentally, and the experimental values agreed very closely with the predicted values.
Cálculo de algunos parámetros de la cristalización de triacilglicéridos de aceites vegetales / Determination of some crystallization parameters for triacylglycerides of vegetable oils
Authors: Toro-Vázquez J.F. , Dibildox-Alvardo E. , Charó-Alonso M.A.
Published: March 2007

A model system with a heterogenous composition of triacylglycerides (TG), in which the component with the highest melting temperature crystallized independently, was developed. Thus, tripalmitin solutions in sesame seed oil (0.98, 1.80 and 2.62% w/v) with ideal crystallization behavior, evaluated through differential scanning calorimetry and the Hildebrand equation, were utilized as a model system to investigate the effect of supercooling and viscosity (η) on the development of polymorph states of TG crystals, their crystal growth mechanism, crystal growth rate constant (z), and activation energy associated with the crystallization process ( Ea). Results indicated that a modification of the Avrami equation, as suggested by Khanna and Taylor, provides reliable values of z and, subsequently, correct estimates of Ea. This was not the case when the original Avrami equation was used. Subse quent analysis indicated that nucleation and crystal growth, as well as the polymorph states devel oped by the TG, depend mainly on η and the extent of supercooling. The latter is a function of the concentration of the TG with the highest melting temperature in the system (e.g. tripalmitin). In conclusion, it is feasible to model the combined effect of supercooling, the viscosity of the liquid phase, and the concentration of the component to crystallize, through multiple variable regression to predict the size, number and polymorph state of the crystals developed during the industrial process of fractional crystallization of vegetable oils and fats. This would allow us to establish process condi tions where a higher yield and separation efficiency of the crystal fraction could be achieved.
Revision: Indicadores del deterioro de la calidad proteica y del valor nutritivo de la leche / Review: Indicators of damage of protein quality and nutritional value of milk
Authors: Ferrer E. , Alegría A. , Farré R. , Abellán P. , Romero F.
Published: March 2007

The nutritional value of milk can be negatively affected by thermal treatments. The quality of the proteins can be modified as a consequence of a set of reactions, the most important of which are the interactions between protein and carbohydrates, also known as Maillard reactions. These reactions can also occur when the storage conditions of moisture and temperature are unfavorable. The differ ent thermal treatments involved in processing milk (pasteurization, sterilization, drying, etc.) lead to different steps of the Maillard reaction and therefore to the formation of different compounds that can be useful as chemical markers of milk alteration, or more exactly of protein alteration. Estimating these markers is useful in monitoring the changes, especially those related to proteins, that happen during processing and storage. A review of the literature on the markers used to evaluate the modi fications that milk undergoes during thermal treatment and subsequent storage was carried out, focusing mainly on proteins. Special attention was paid to the analytical aspects. The chemical mark ers taken into account can be classified into two groups according to their relation with the Maillard reaction:

1. Specific markers of Maillard reaction: undesirable compounds (furosine, lisinoalanine, histidinalanine, furfurals, melanoidins); loss of nutrients (available lysine).

2. Non-markers of Maillard reaction: galactose; lactulose; protein-reducing substances; denaturation of protein; in vitro digestibility of proteins; others—pH, viscosity, free fatty acids.
Establishing a Compliance Plan in an Era of Austerity
Authors: Leahy Larry , Constant Ruth L.
Published: March 2007

With the publishing of the Office of Inspector General's (OIG's) compliance program guidance for home health agencies, the OIG has given notice to the home care sector that home health providers should have in place, or be developing, effective and well-run compliance programs. Many providers, facing numerous regulatory mandates, are questioning whether they can afford to develop a non-mandatory compliance program. Fortunately, with an understanding of the purpose of compliance programs, most providers can create and implement their own program. This article describes how one organization, with senior leadership's involvement and a basic understanding of the Federal Sentencing Guidelines, implemented a program that complies with the OIG's guidance.
The Relationship between Purchaser Type and Home Health Utilization and Outcomes
Authors: Adams Carolyn E. , Moore Jayne Furness , Michel Yvonne
Published: March 2007

The study's purpose was to compare characteristics, service utilization, and outcomes of home health patients enrolled in fee-for-service (FFS) versus health maintenance organization (HMO) health plans. Results documented that HMO patients were healthier and used fewer resources than FFS patients. Outcomes for HMO patients were superior to those of FFS patients. Phi correlation coefficients showed that purchaser type was not a substantial predictor of patient outcomes. Home health staff need to begin intense case management of FFS patients to identify when patient outcomes are maximized and continued services will not further improve or stabilize the patient's condition.
Self-Directed Work Teams in a Health Care Environment
Authors: Cartmell Kavin H.
Published: March 2007

The article provides an overview of self-directed work teams in a health care environment. It defines what a self-directed work team is; what is required to successfully implement one; the critical elements involved to ensure success; how the team can be used to empower personnel, set goals, and measure them; and the benefits of this particular model of conducting business.
Home infusion therapy for the person with HIV disease
Authors: Shearer Nancy , Lampert Andrea I. , Dienes Robert
Published: March 2007

This article focuses on home infusion nursing care for the person with HIV disease. Included are criteria for patient selection, common infusion therapies, a model care plan, and information on possible resources available in the community. There are also suggestions for forming home care and community alliances to provide support for the HIV-infected patient and his or her family.
Alzheimer's from a caregiver's perspective
Authors: Kirkland Glenn I.
Published: March 2007

The author shares his own personal experiences with Alzheimer's disease and dis cusses the many issues involved including the diagnostic process, legalities, support groups, and financial issues. Throughout this very helpful article, the reader will find resource information, both reading and organizational in nature, which will inform the professional caregiver and ultimately assist the families cared for.
Technology in pediatric home care: Issues in monitoring for quality
Authors: Monahan Colleen , Mnnago Rosemary
Published: March 2007

This article provides information for consumers regarding standards for the use of tech nology in the home health care pediatric program. The authors describe studies and the experience of one state agency. They provide questions and arguments that can be uti lized by hospital discharge planners, case managers, home health care service providers, and families.
Adapting wound care for complex patients
Authors: Stotts Nancy A. , Wipke-Tevis Deidre D.
Published: March 2007

This article describes the management of complex patients with wounds. Basic prin ciples of wound care, understanding the patient's underlying condition, interdiscipli nary approaches to care, and case studies are included.
Functional outcomes of patients with hip fracture in the home health care setting
Authors: Moore Ann
Published: March 2007

The article shares the information gathered for a 1-year period by a home health care agency regard ing the outcomes achieved with the care of patients with fractured hips. The study shows the functional gains made through therapy in the home care setting. Physical therapy and occupational therapy short-term goal guidelines are presented for consideration as well.
Confronting crisis in the European steel industry: diagnosis and strategy
Authors: Pichierri Angelo
Published: March 2007

At the time of the 1974 crisis, the European steel industry had long been in decline. The crisis of the 1970s was not the beginning of the process but a pow erful accelerating factor. The almost complete inability of most of the actors involved to take the available indicators into account is explained by an unfor tunate combination of structural characteristics of the industry (cyclical fea tures, time needed for strategy implementation, barriers to exit) and subjective beliefs and ideologies.

For many years, the typical behavior of most steel industry actors was an example of parametric rationality (do as before) or overcompensation (do as before, but more). In very few cases was decline perceived and dealt with be fore the crisis. Increasingly, strategies of management of decline are adopted, aimed at lowering and distributing the social and economic costs of contrac tion. Given its nature and costs, this strategy is typically implemented by actors (national governments, the Commission of the European Communities) other than those directly involved.