bluuebunny/crossref_metadata_2025 huggingface dataset:
Brand Community Members as a Source of Innovation
Authors: Füller Johann , Matzler Kurt , Hoppe Melanie
Published: September 2008

Brand community members have a strong interest in the product and in the brand. They usually have extensive product knowledge and engage in product‐related discussions; they support each other in solving problems and generating new product ideas. Therefore, brand communities can be a valuable source of innovation. So far, little is known about the member's ability and willingness to participate in a company's innovation process. How does passion for the brand, affiliation to the brand community, and trust in the brand affect the willingness to engage in a company's innovation process? What is the effect of brand passion on brand knowledge and on domain‐specific skills, which are considered important prerequisites for qualified and creative contributions to new product development? What is the effect of personality traits on the willingness and ability to engage in new product development? This research addresses these questions, which are interesting for managers who are thinking about opening up their innovation process and collaborating with brand communities and for academics exploring the opportunities of online communities for new product development and trying to develop promising new forms of open innovation networks. Drawing on brand community literature, relationship theory, creativity theory, and personality traits research, this paper introduces a comprehensive set of antecedents affecting brand community members' willingness to engage in new product development. It is argued that consumer creativity, identification with the brand community, and brand‐specific emotions and attitudes (passion and trust) as well as brand knowledge are important determinants of consumers' willingness to share their knowledge with producers. The paper also identifies two personality traits (i.e., extraversion and openness) that have significant influence on brand passion, creativity, and identification with the community. The hypotheses are tested on a sample of 550 members of the Volkswagen Golf GTI car community. Structural equation modeling was used to test the relationship among the constructs. Though a positive disposition toward a brand may be advantageous for consumers that are willing to interact with producers during new product development, our results show that it is consumer interest in innovations and the innovative process that drives them to get involved. Further, brand community members with more knowledge and more innovative skills seem to be more willing to contribute than less qualified community members.
Antecedents and Consequences of Information Technology Usage in NPD: A Comparison of Dutch and U.S. Companies*
Authors: Barczak Gloria , Hultink Erik Jan , Sultan Fareena
Published: September 2008

This study examines information technology (IT) usage for new product development (NPD) in a global context. Specifically, this research seeks to ascertain the factors that influence IT usage and the relationship between IT usage and new product performance in two different countries—the United States and the Netherlands. The interest here is in discovering if, and how, these relationships may be different depending on the country within which the NPD effort is undertaken. Employing a mail survey methodology, the present study uses data from a sample of U.S. practitioner members from the Product Development & Management Association (PDMA) and new product managers from Dutch manufacturing companies to examine the effect of IT infrastructure, IT embeddedness, NPD process formalization, colocation, outsourcing of NPD projects, and length of time on the job on the extent of IT usage. The data are also used to explore the impact of IT usage on speed to market and market performance. The results indicate that IT embeddedness and NPD process formalization positively influence IT usage in both the United States and the Netherlands. Colocation and length of time on the job are negatively associated with IT usage only in Dutch firms. Similarly, outsourcing of NPD projects is positively related to IT usage only in U.S. firms. Finally, IT usage has a positive relationship with speed to market in the Netherlands and with market performance in the United States. An important implication of the present study is that IT usage does impact speed to market and market performance, confirming anecdotal evidence. However, these relationships are not the same in each country. Moreover, the antecedents to IT usage also vary by country. Thus, the precursors and consequences of IT usage in NPD are context specific. Another implication of this research is that unless IT is embedded into the NPD process, it is unlikely that the benefits of IT will come to fruition. Finally, this study suggests that as firms use more globally dispersed teams for NPD and outsource more of their development activities, IT usage is likely to increase to facilitate communication and cooperation.
Paradise Bound: A Perennial Tradition or an Unseen Process of Cosmological Hybridization?
Authors: LAHOOD GREGG
Published: September 2008

A genealogical excavation of the pre transpersonal movement uncovers a hitherto unrecognized process of hybridity and syncretism occurring in the 1960s U.S. counter culture. The presence of hybridity in the movement's prehistory has serious repercussions for current maps in transpersonalism (and religious enactments in general). It is argued here that current transpersonal theories have built themselves on an unexamined foundation of magic, sorcery, and cosmological hybridization.Ken Wilber'sneoperennialist cosmos will be construed as an assimilationist strain of hybridity. Jorge Ferrer's more culture‐friendly postulate of an “Ocean with Many Shores” suggests a kind of cosmological multiculturalism. However, what appear to be fixities in his cosmology lend themselves to critical reevaluation of this aspect of his revision of transpersonal psychology.
Prosthetically Driven, Computer‐Guided Implant Planning for the Edentulous Maxilla: A Model Study
Authors: Katsoulis Joannis , Pazera Pawel , Mericske‐Stern Regina
Published: September 2008

Objectives:To analyze computer‐assisted diagnostics and virtual implant planning and to evaluate the indication for template‐guided flapless surgery and immediate loading in the rehabilitation of the edentulous maxilla.

Materials and Methods:Forty patients with an edentulous maxilla were selected for this study. The three‐dimensional analysis and virtual implant planning was performed with the NobelGuide™ software program (Nobel Biocare, Göteborg, Sweden). Prior to the computer tomography aesthetics and functional aspects were checked clinically. Either a well‐fitting denture or an optimized prosthetic setup was used and then converted to a radiographic template. This allowed for a computer‐guided analysis of the jaw together with the prosthesis. Accordingly, the best implant position was determined in relation to the bone structure and prospective tooth position. For all jaws, the hypothetical indication for (1) four implants with a bar overdenture and (2) six implants with a simple fixed prosthesis were planned. The planning of the optimized implant position was then analyzed as follows: the number of implants was calculated that could be placed in sufficient quantity of bone. Additional surgical procedures (guided bone regeneration, sinus floor elevation) that would be necessary due the reduced bone quality and quantity were identified. The indication of template‐guided, flapless surgery or an immediate loaded protocol was evaluated.

Results:Model (a) – bar overdentures: for 28 patients (70%), all four implants could be placed in sufficient bone (total 112 implants). Thus, a full, flapless procedure could be suggested. For six patients (15%), sufficient bone was not available for any of their planned implants. The remaining six patients had exhibited a combination of sufficient or insufficient bone. Model (b) – simple fixed prosthesis: for 12 patients (30%), all six implants could be placed in sufficient bone (total 72 implants). Thus, a full, flapless procedure could be suggested. For seven patients (17%), sufficient bone was not available for any of their planned implants. The remaining 21 patients had exhibited a combination of sufficient or insufficient bone.

Discussion:In the maxilla, advanced atrophy is often observed, and implant placement becomes difficult or impossible. Thus, flapless surgery or an immediate loading protocol can be performed just in a selected number of patients. Nevertheless, the use of a computer program for prosthetically driven implant planning is highly efficient and safe. The three‐dimensional view of the maxilla allows the determination of the best implant position, the optimization of the implant axis, and the definition of the best surgical and prosthetic solution for the patient. Thus, a protocol that combines a computer‐guided technique with conventional surgical procedures becomes a promising option, which needs to be further evaluated and improved.
Two‐Year Outcome with Nobel Direct® Implants: A Retrospective Radiographic and Microbiologic Study in 10 Patients
Authors: Van de Velde Tommie , Thevissen Eric , Persson G. Rutger , Johansson Carina , De Bruyn Hugo
Published: September 2008

Introduction: The Nobel Direct® implant (Nobel Biocare AB, Göteborg, Sweden) was developed to minimize marginal bone resorption and to result in “soft tissue integration” for an optimized aesthetic outcome. However, conflicting results have been presented in the literature. The aim of this present study was to evaluate the clinical and microbiologic outcomes of Nobel Direct implants.

Materials and Methods: Ten partially edentulous subjects without evidence of active periodontitis (mean age 55 years) received 12 Nobel Direct implants. Implants were loaded with single crowns after a healing period of 3 to 6 months. Treatment outcomes were assessed at month 24. Routine clinical assessments, intraoral radiographs, and microbiologic samplings were made. Histologic analysis of one failing implant and chemical spectroscopy around three unused implants was performed. Paired Wilcoxon signed‐rank test was used for the evaluation of bone loss; otherwise, descriptive analysis was performed.

Results: Implants were functionally loaded after 3 to 6 months. At 2 years, the mean bone loss of remaining implants was 2.0 mm (SD ± 1.1 mm; range: 0.0–3.4 mm). Three out of 12 implants with an early mean bone loss >3 mm were lost. The surviving implants showed increasing bone loss between 6 and 24 months (p = .028). Only 3 out of the 12 implants were considered successful and showed bone loss of <1.7 mm after 2 years. High rates of pathogens, including Aggregatibacter actinomycetemcomitans, Fusobacterium spp., Porphyromonas gingivalis, Pseudomonas aeruginosa, and Tanerella forsythia, were found. Chemical spectroscopy revealed, despite the normal signals from Ti, O, and C, also peaks of P, F, S, N, and Ca. A normal histologic image of osseointegration was observed in the apical part of the retrieved implant.

Conclusion: Radiographic evidence and 25% implant failures are indications of a low success rate. High counts and prevalence of significant pathogens were found at surviving implants. Although extensive bone loss had occurred in the coronal part, the apical portion of the implant showed some bone to implant integration.
Cone‐Beam CT for Preoperative Implant Planning in the Posterior Mandible: Visibility of Anatomic Landmarks
Authors: Lofthag‐Hansen Sara , Gröndahl Kerstin , Ekestubbe Annika
Published: September 2008

Background: The technical development has given a new type of modality, cone‐beam computed tomography (CBCT). This technique has a high potential to solve different diagnostic problems among which is preoperative planning for implants in the posterior mandible.

Purpose: The aim of this retrospective study was to evaluate the visibility of the mandibular canal and the marginal bone crest and the agreement between observers in images from one CBCT technique.

Materials and Methods: Thirty consecutive patients were examined with 3D Accuitomo® (J. Morita Mfg. Corp., Kyoto, Japan) in one side of the mandible, where the second premolar and molars were lost. The examined volume was 30 by 40 mm. Seven observers evaluated the visibility and the location of the mandibular canal and the marginal crest by visually deciding if the structures were clearly visible, probably visible, or invisible in one cross‐sectional image, approximately 1 cm posterior to the mental foramen. In a later session, the observers also marked the two anatomic structures. If the decision was not “clearly visible” or if the anatomic structures were difficult to identify, the observers had to use other cross‐sectional, axial, and/or sagittal images in the volume.

Results: The confidence among the observers evaluating the marginal bone crest was high. Two observers never used any other images, and the rest took help in two to seven cases. When marking the mandibular canal, the observers, in general, used more images. In five cases (17%), all the observers only used the single cross‐sectional image. The agreement on the position of the canal was also high.

Conclusion: With this CBCT modality (3D Accuitomo), the visibility of the mandibular canal and the marginal crest, as well as the observer agreement of the location of these structures, was high. Hence, the 3D Accuitomo can be recommended for implant planning in the posterior mandible.
Cemented CeraOne® and Porcelain Fused to TiAdapt™ Abutment Single‐Implant Crown Restorations: A 10‐Year Comparative Follow‐Up Study
Authors: Jemt Torsten
Published: September 2008

Background: Long‐term data comparing cemented and noncemented single‐implant restorations has not been reported.

Aim: To compare clinical and radiographic performance of single‐implant crown restorations made by either directly baked porcelain to custom‐made TiAdapt™ titanium abutments (Nobel Biocare AB, Göteborg, Sweden) (test) or cement crowns onto CeraOne® (Nobel Biocare AB) abutments (control) after 10 years in function.

Materials and Methods: Altogether, 35 consecutive patients were provided with 41 turned single Brånemark System® implants (Nobel Biocare AB) in the partially edentulous upper jaw. By random, 15 and 20 patients were provided with 18 test and 23 control implant crowns, respectively. Thereafter, clinical and radiographic data were collected and compared between the two groups.

Results: None of the implants were found loose during the follow‐up period (100%). Few clinical problems were observed, and the overall average marginal bone loss was 0.26 mm (SD 0.64) during 10 years in function. After the final tightening of the crowns, no significant differences were observed between the test and control groups (p > .05). The head of the implants was placed on an average 6.3 mm (SD 2.24) below the cement/enamel junction of the adjacent teeth (range 2.5–10.0 mm). Implants with reported mechanical and/or mucosal problems or placed more apically in relation to the adjacent teeth did not present more bone loss as compared with implants with no problems or placed more coronally, respectively (p > .05).

Conclusions: There seems to be no obvious clinical or radiographic differences between the test and control single‐implant restorations during 10 years of follow‐up. Occasionally, some restorations presented loose abutment screws and/or fistulas during follow‐up. This implies a certain need for maintenance where a one‐piece single‐implant protocol (test) allows both for a simple clinical procedure at placement without cementation problems, as well as for an easy and simple maintenance of installed single implant crowns in long‐term function.
Effect of Diameter and Length on Stress Distribution of the Alveolar Crest around Immediate Loading Implants
Authors: Ding Xi , Liao Sheng‐Hui , Zhu Xing‐Hao , Zhang Xiu‐Hua , Zhang Lin
Published: September 2008

Background: Many clinical observations have shown that immediate loading is indicated when the stabilization of the bone/implant is optimal and when the estimated loads are not excessively high. Nonetheless, more experimental studies are needed to consider the immediate loading protocol as a safe procedure. Mechanical analysis using the finite element (FE) method analysis has been employed by many authors to understand the biomechanical behavior around dental implants.

Purpose: This study was to evaluate the effect of the diameter and length on the stress and strain distribution of the crestal bone around implants under immediate loading.

Materials and Methods: By an ad hoc automatic mesh generator, high‐quality FE models of complete range mandible was constructed from computer tomography, with three Straumann (Straumann Institute, Waldenburg, Switzerland) implants of various sizes embedded in the anterior zone. The implant diameter ranged from 3.3 to 4.8 mm, and length ranged from 6 to 14 mm, resulting in seven designs. The implant–bone interface was simulated by nonlinear frictional contact algorithm. For each design, vertical and oblique loadings of 150 N were applied, respectively, to each implant, and stresses and strains in the surrounding cortical bone were evaluated.

Results: The biomechanics analysis provided results that the oblique loading would induce significantly higher interfacial stresses and strains than the vertical loading, while the intergroup stress difference significant levels was evaluated using t‐tests method and the level of significance (.05) that was accepted for significance. Under both loadings, the maximal values were recorded in the 3.3 (diameter) × 10 (length) mm implant configuration, whose mean and peak values were both higher than that of others with significant statistical differences. The second maximal one is 4.1 × 6 mm configuration, and the minimal stresses were recorded in 4.8 × 10 mm configuration, whose strains were also near to lowest.

Conclusions: Increasing the diameter and length of the implant decreased the stress and strain on the alveolar crest, and the stress and strain values notably increased under buccolingual loading as compared with vertical loading, but diameter had a more significant effect than length to relieve the crestal stress and strain concentration.
Credibility of a Meta‐Analysis: Evidence‐Based Practice Concerning Soy Intake and Breast Cancer Risk in Premenopausal Women
Authors: Delaune Allyson , Landreneau Kandace , Hire Katie , Dillard Brenda , Cox Melissa , Payne Karen , Powell Carol
Published: September 2008

Purpose: To report the findings from a critical appraisal concerning the credibility of a meta‐analysis (M‐A) about the role of dietary soy intake in reducing breast cancer risk. The use of an evidence‐based, advanced nursing practice framework was used to appraise the M‐A.

Approach: The clinical question was developed from a problem that could be encountered in clinical practice. For premenopausal women, does the use of high dietary soy intake reduce the future risk of breast cancer compared with low dietary soy intake? A search of electronic databases yielded one M‐A, which was selected to answer the question.

Framework: A framework was developed from various authors' work and used to appraise the M‐A and guide implementation of the evidence‐based practice (EBP) process.

Conclusions: The findings of the M‐A were not deemed credible because of deficient information regarding the target population and outcome variable, lack of confounder control, unclear inclusion and exclusion criteria of the sample, and invalid methods of data abstraction. Because the findings were not credible, they were deemed not to be clinically applicable. Therefore, a high soy diet would not necessarily be recommended.
Evidence‐Based Education and Nursing Pressure Ulcer Prevention Textbooks: Does It Match?
Authors: Wilborn Doris , Halfens Ruud J. , Dassen Theo
Published: September 2008

Background: The education of nurses has influenced the way of nursing practice for a long time. Nurse educators are required to offer up‐to‐date educational material, and textbooks are the most frequently used sources of knowledge during a nurse's education.

Aim: In this study, researchers investigated the extent to which textbooks were evidence based regarding preventing pressure ulcers and knowing what recommendations to make for nursing students and publishers of nursing textbooks.

Method: Educators at nursing schools in Germany were contacted by telephone to identify the most often used nursing textbooks. The recommendations of the German Expert Standard of Pressure Ulcer Prevention were compared with the content of the textbooks in a content analysis. Additionally, teachers were asked what additional material they were using to help prepare lectures.

Results: Only one of the four analysed textbooks complied with the recommendations of the German Expert Standard. Contents of the other books were incomplete. The authors of some books did not mention any up‐to‐date scientific evidence. The teachers often used additional material such as the German Expert Standard and research articles to prepare their lectures.

Discussion: German nursing textbooks were classified into research‐based and authoritative texts. Because of the fast development and availability of research findings, one recommendation is that new forms of “textbooks” such as CD ROMs should be considered.
DEVELOPMENT OF A CONTINUOUS METHOD FOR PUFFING AMARANTH (AMARANTHUS SPP.) SEEDS
Authors: TIKEKAR ROHAN V. , KARWE MUKUND V.
Published: September 2008

Amaranth (Amaranthus spp.) is a nutritionally dense pseudocereal grown mostly in South America and Asia. Traditionally amaranth seeds are puffed using a hot skillet. Besides being a batch system, in this process there is little control over the temperature and the residence time of the seeds. We have developed a continuous technique for puffing amaranth seeds using a single‐screw extruder with a tapered screw without a die. With this technique we could control the temperature and the residence time for puffing the seeds. It was found that the puffing efficiency of amaranth seeds was a function of temperature and screw speed. The maximum efficiency of 86% was achieved at a barrel temperature of 290C and screw speed of 125 rpm. Sensory analyses with an untrained panel of 33 subjects using samples generated at conditions with puffing efficiency above 75% showed that the sample processed at 250C and 75 rpm was the most acceptable in terms of various sensory attributes and overall liking.

PRACTICAL APPLICATIONS

The research aims to develop a new continuous process for the puffing of amaranth seeds. The use of an extruder without a die for puffing these seeds is a novel idea. This process could possibly be used for puffing several other seeds and grains, making it a versatile technology. The sensory work conducted in this paper aims at examining the acceptance of this relatively new product among U.S. consumers.
OPTIMIZATION OF EXTRUSION COOKING OF CORNMEAL AS RAW MATERIAL FOR BAKERY PRODUCTS
Authors: CURIC D. , NOVOTNI D. , BAUMAN I. , KRICKA T. , DUGUM J.
Published: September 2008

The objective of this work was the optimization of extrusion process for the production of extruded cornmeal (ECM) that may be used in the production of corn bread by a direct procedure. The extrusion process variables, barrel temperature, Et (111–159C), moisture content, Mc (12.10–24.77%) and screw speed, Ss (160–460 rpm), were considered and their influence on moisture content of milled extrudates (ME), expansion index (EI), bulk density (BD), water solubility index (WSI), water absorption index (WAI) and cold paste viscosity (CPV) of extrudates was investigated. The influence of ECM addition on viscosity of wheat flour and cornmeal mixture was monitored. The optimimum combination of extrusion conditions was Mc = 21.21%; Et = 145C; Ss = 263.5 rpm. The properties of ECM under optimal extrusion conditions were Mc, 10.97%; EI, 4.22; WAI, 7.84 g gel/g dm; WSI, 14.88%; BD, 36.35 g/100 mL and CPV, 1,220 BU. In the quantity of 30% calculated on the wheat flour quantity, the ECM can be used for the production of corn breads by a direct procedure.

PRACTICAL APPLICATION

Corn flour obtained by dry milling of maize, namely in a mixture with wheat flour, has been used in Southeastern Europe for centuries in theproduction of bakery products. Cornstarch granules swell more slowly and gelatinize at a higher gelatinization temperature than starch granules of wheat flour, while corn proteins are incapable of dough formation. The properties of finished corn bakery products depend significantly on the quantity and temperature of the boiling water used for the mix (60–100% of total water quantity added to the mix) and the steaming time of the corn flour (3–12 h), which is the first and critical stage in the process of corn bread and rolls production. The quality of finished products depends significantly on the baker's experience.

The purpose of this work was to determine the optimal extrusion process variables for the production of the gelatinized cornmeal that can be used in the production of bakery products by a direct procedure, without prior steaming of cornmeal. This could significantly reduce the processing time and energy consumption, while the product will still be of consistent and even better quality.
CLARIFICATION AND PURIFICATION OF AQUEOUS STEVIA EXTRACT USING MEMBRANE SEPARATION PROCESS
Authors: REIS M.H.M. , DA SILVA F.V. , ANDRADE C.M.G. , REZENDE S.L. , WOLF MACIEL M.R. , BERGAMASCO R.
Published: September 2008

Stevia rebaudiana Bertoni is a native plant from South America and its active constituents have been considered the “sweeteners of the future.”Stevia is a natural diet‐sweetening source, safe to health and without calories. However, the obtained raw extract is foul smelling, bitter tasting, dark brown colored, and presents suspension matter due to organic and inorganic compounds. Therefore, further purification/clarification is essential in order to get a product of commercial quality. In this work ceramic membranes were applied in the stevia extract clarification process. The process was carried out under different membrane pore sizes and at different pressure values. The best clarification result was obtained with the membrane of 0.1 µm at 4 bar. On the other hand, the best condition for the flux was obtained with the membrane of 0.2 µm at 6 bar. The process with all the tested membranes and conditions achieved recovery of sweeteners higher than 90%. Finally, a filtration mathematical model was applied to describe the flux behavior, showing that the main fouling phenomenon during the process occurred because of the complete blocking of pores.

PRACTICAL APPLICATION

Stevia is the world's only all‐natural sweetener with zero calories, zero carbohydrates and a zero glycemic index. However, the obtained stevia extract has a dark brown appearance, mainly because of the presence of impurities. In this work the membrane separation process was studied for stevia extract clarification and purification in order to get a product with higher commercial acceptability. The obtained results showed that total clarification and recuperation of sweeteners was almost achieved. Nonetheless, membrane fouling is an inevitable problem during membrane filtration. The mathematical analysis of the fouling occurrences showed that the complete blocking of pores is the main cause for the membrane permeability decrease.
OPTIMIZATION OF PERMEABILIZATION PROCESS FOR LACTOSE HYDROLYSIS IN WHEY USING RESPONSE SURFACE METHODOLOGY
Authors: KAUR GURPREET , PANESAR PARMJIT S. , BERA MANAV B. , SINGH BAHADUR
Published: September 2008

To overcome the permeability barrier and prepare whole cell biocatalysts with high activities, permeabilization of Kluyveromyces marxianus var. lactis NCIM 3566 in relation toβ‐galactosidase activity was optimized using cetyltrimethylammonium bromide (CTAB) as permeabilizing agent. Permeabilized whole cells can be advantageous over pure enzyme preparations in terms of cost‐effectiveness and increased stability maintained by the intracellular environment. Response surface methodology (RSM) was applied to optimize concentration of CTAB, temperature and the treatment time for maximum permeabilization of yeast cells. The optimum operating conditions for permeabilization process to achieve maximum enzyme activity obtained by RSM were 0.06% (w/v) CTAB concentration, 28C temperature and process duration of 14 min. At these conditions of process variables, the maximum value of enzyme activity was found to be 1,334 IU/g. The permeabilized yeast cells were highly effective and resulted in 90.5% lactose hydrolysis in whey.

PRACTICAL APPLICATION

β‐Galactosidase is one of the most promising enzymes, which has several applications in the food, fermentation and dairy industry. However, the industrial applications of β‐galactosidase have been hampered by the costs involved in downstream processing. The present investigation was focused on developing the low‐cost technology for lactose hydrolysis based on permeabilization process. Disposal of lactose in whey and whey permeates is one of the most significant problems with regard to economics and environmental impact faced by the dairy industries. Keeping this in view, lactose hydrolysis in whey has been successfully performed using permeabilized Kluyveromyces marxianus cells. Hydrolysis of lactose using β‐galactosidase converts whey into a potentially very useful food ingredient, which has immense applications in food industries. Its use has increased significantly in recent years, mainly in the dairy products and in digestive preparations. Lactose hydrolysis causes several potential changes in the manufacture and marketing of dairy products, including increased solubility, sweetness and broader fermentation possibilities.
EFFECT OF HIGH‐PRESSURE PROCESSING ON TEXTURE AND DRYING BEHAVIOR OF PINEAPPLE
Authors: KINGSLY A.R.P. , BALASUBRAMANIAM V.M. , RASTOGI N.K.
Published: September 2008

The effect of high‐pressure processing on texture and drying behavior of pineapple slices was investigated. Pineapple slices were high pressure processed at 50, 100, 300, 500 and 700 MPa at 25C for 10 min. The control, hot water‐blanched and high‐pressure processed samples were then dehydrated at 70C. Application of high pressure reduced the sample hardness, springiness and chewiness while it had no significant effect on cohesiveness of pineapple. Elevated pressure treatment (≥500 MPa) reduced drying time more effectively than for the other pretreated samples. Experimental dehydration data were empirically fitted using six thin‐layer drying models. Among the models tested, logarithmic model best described the drying behavior of pineapple slices. The effective moisture diffusivity was found to increase with an increase in the level of pressure up to 500 MPa, and the samples processed at 500 and 700 MPa had higher diffusivity values than blanched samples.

PRACTICAL APPLICATIONS

This work shows that high‐pressure blanching of pineapple can be an alternative for hot water blanching, before dehydration. The results may find application in development of quality snack food from pineapple fruits.
HEATING UNIFORMITY AND RATES IN A DOMESTIC MICROWAVE COMBINATION OVEN
Authors: RAKESH V. , DATTA A.K. , AMIN M.H.G. , HALL L.D.
Published: September 2008

Physics‐based modeling complemented with magnetic resonance imaging (MRI) for validation can provide a novel means to understand and thereby optimize combination heating processes. The objectives of this study were to compare heating patterns in a combination of radiant, forced air and microwave oven measured by MRI with those predicted by coupled electromagnetics‐heat transfer model; quantify speed and uniformity of heating for the different combination modes; determine the effect of food dielectric properties on heating patterns; and delineate the nature of individual heating modes and their combinations. The modes of radiant heating through heating elements and forced convection by fan led to a more uniform heating compared with the faster (but less uniform) heating method provided by the microwaves. Combination methods were faster than radiant, forced‐air and microwave‐only heating. Although the speed of heating increased appreciably for combination modes, the nonuniformity of heating did not increase as much.

PRACTICAL APPLICATIONS

The results from the study can be used to develop design recommendations/guidelines for combination heating for different thermal processes such as baking, broiling, roasting and reheating of different materials, grouping them based on their properties. The research can benefit the consumers, food services and equipment manufacturers to understand the combination heating process in a better way and to, thereby, use it efficiently. Without a fundamental understanding of the effect of various combinations, optimization of heating can be intractable. The fundamental approach used in this study would, therefore, help consumers and food services in preparation of safe and high‐quality foods through combination heating. The work would also help equipment manufacturers in optimizing the designs of combination‐heating ovens.
Do switching costs make markets more or less competitive? The case of 800‐number portability
Authors: Viard V. Brian
Published: September 2008

Do switching costs reduce or intensify price competition if firms charge the same price to existing and new consumers? I study 800‐number portability to determine how switching costs affect price competition under a single price regime. AT&T and MCI reduced their toll‐free services prices in response to portability, implying that reduced switching costs increased competition. Despite rapid market growth, gains from higher prices to “locked‐in” consumers exceeded the incentives to capture new consumers. Prices on larger contracts dropped more, consistent with greater lock‐in for larger users. Price changes between portability's announcement and implementation are consistent with rational expectations.
The welfare effects of third‐degree price discrimination with nonlinear demand functions
Authors: Cowan Simon
Published: September 2008

The welfare effects of third‐degree price discrimination are analyzed when demand in one market is an additively shifted version of demand in the other market and both markets are served with uniform pricing. Social welfare is lower with discrimination if the slope of demand is log concave or the convexity of demand is nondecreasing in the price. The demand functions commonly used in models of imperfect competition satisfy at least one of these sufficient conditions.
Spatial organization of firms: the decision to split production and administration
Authors: Aarland Kristin , Davis James C. , Henderson J. Vernon , Ono Yukako
Published: September 2008

A firm's production activities are often supported by nonproduction activities, such as administrative units including headquarters, which process information both within and between firms. Firms may physically separate such administrative units from their production activities and create stand‐alone central administrative offices (CAOs). However, activities in multiple locations may cause internal communication costs. What types of firms are more likely to separate such functions? If firms separate administration and production, where do they locate CAOs? This paper examines firms' spatial organization using microlevel data from the US Census Bureau.
Delegation and incentives
Authors: Bester Helmut , Krähmer Daniel
Published: September 2008

This article analyzes the relation between authority and incentives. It extends the standard principal‐agent model by a project selection stage in which the principal can either delegate the choice of project to the agent or keep the authority. The agent's subsequent choice of effort depends both on monetary incentives and the selected project. We find that the consideration of effort incentives makes the principal less likely to delegate the authority over projects to the agent. In fact, if the agent is protected by limited liability, delegation is never optimal.
Acoustical and sound system design considerations in large venues and stadia
Authors: Wrightson Jack , Baker Ron , Day Kevin
Published: September 2008

Large, spectator seating facilities provide unique challenges for the sound and acoustical system designer. The challenges are equally daunting, but different for indoor and outdoor facilities. This presentation provides empirical data of existing facilities in regard to speech intelligibility, uniformity of sound reinforcement coverage, maximum loudness, etc., along with a review of predicted modeling and auralization techniques. Design guidelines for acoustical treatment, loudspeaker configuration, predictive calculation of speech intelligibility, and other aspects will be discussed. Difference or variations in design practice between more conventionally sized spaces and very large environments will be presented.
The implications of scale on sound systems in large spaces
Authors: McCarthy Bob
Published: September 2008

The symphonic concert hall is a well documented reference point for matters of scale in the musical side of architectural acoustics. Larger spaces may have comparable shapes, and yet the matters of scale require vastly different approaches in regard to the sound system and architectural acoustics. The causes and consequences of scalar expansion will be discussed as well as the shifting balance between the roles of the sound system and the architectural acoustics. Sound system and acoustical designs must adapt to those aspects which are modified by scale (power, distance, wavelength, etc.) along with those that remain constant, regardless of the size (angular aspects, echo perception, the spacing between and size of audience members, etc.). Expanded room scale requires the sound system to use increasingly effective methods of controlling the direct sound field to tailor its response to the highly asymmetric shapes presented for coverage. The methods of control and their implication on the hall acoustics will be discussed. Scalar independent methods for sound system designs which can be form-fitted into a space will be discussed in the context of a variety of large room examples.
Stadium acoustics-design challenges and solutions
Authors: Marsh David
Published: September 2008

Large stadiums, whether enclosed or open-air, present many acoustical design challenges including excessive reverberation, echoes from surfaces distant from the sound system loudspeakers, sound absorption by air, refraction, difficulty achieving acceptable speech intelligibility, and synchronization of the sound reinforcement system to the video boards. This paper is an overview of how these challenges have been met in several professional sports facilities. Reverberation times for these large venues are normally underpredicted on the order of −20% by conventional methods. Low frequency reverberation times (down to 63 Hz) tend to be extremely long—about 15 s on average. A novel approach will be described to estimate these values (within a wide range of possibilities) based on in situ measurement data. It will be shown that after exhausting all possibilities of acoustical treatments, the most effective way of achieving acceptable speech intelligibility is to use a distributed sound system with no seat being more than about 80 ft from the nearest loudspeaker.
Purpose built sound systems for large rooms
Authors: Shaw Neil A. , Monitto John
Published: September 2008

Sound systems for sports facilities have improved over the years with the development of better loudspeaker systems with increased headroom and reduced distortion at high sound levels. Today’s loudspeaker systems can produce cleaner sound with less interference between the devices, when installed either temporarily or permanently in these often very reverberant venues. Two basic design philosophies for football, baseball, and soccer stadiums are the point source and the distributed system. Smaller basketball, hockey and other sports typically have sound systems flanking scoreboards in a point source design with the option of distributed delayed speakers. In some new facilities that are designed for multipurpose use, the use of electronic processing systems enables these rooms to be designed with lower reverberation times, which is typically the preferred acoustic environment for live amplified concerts. For games and other events a variable acoustic system provides additional reverberation as needed, also enhancing natural crowd and court sounds, such as a ‘‘puck’’ sound, and increases the intimacy of applause and cheering between the fans and the game itself.
Signal-to-noise ratios in sound system design
Authors: Long Marshall
Published: September 2008

An important consideration in sound system design is intelligibility, and the most common measure of intelligibility is some sort of signal-to-noise ratio. Intelligibility can be expressed in terms of a goodness ratio (high signal-to-noise) or a badness ratio (high noise-to-signal), or a modified badness ratio (noise x reverberation time)/signal such as %ALcons. The trick is how to calculate signal, how to calculate noise, and how to design systems with what we calculate. Three types of solutions: Cabinets (horns), distributed loudspeakers, and line arrays are discussed.
The effect of grain shape on the porosity of marine sediments
Authors: Barclay David R. , Buckingham Michael J.
Published: September 2008

The porosity of marine sediments increases as the mean grain diameter decreases. In contrast, the close-packing structures (including random packing) of uniform-size spheres all show a porosity that is independent of sphere size. Hamilton suggested that, in sediments, the shape of the grains is instrumental in determining the porosity. To investigate this idea, experiments have been performed on a variety of sand samples (marine sediments, beach sands, and desert sands) with mean radii within the range 30 mm–200 mm. The macroscopic properties (porosity and bulk density) are measured in simple tabletop experiments, while the microscopic details of grain shape are quantified using an optical microscope and image-analysis software. For each grain in, typically, a sample of several hundred, the boundary is traced and various geometric parameters are returned, including the perimeter, the cross-sectional area, the centroid, and the best-fit ellipse. Also, a Fourier decomposition yields the radius as a function of angle, and the higher-order coefficients are then combined to provide a description of grain shape (i.e., deviation from sphericity). An attempt is being made to interpret the observed porosities in terms of the measured grain shapes. [Research supported by ONR.]
Shear waves and the discrepancy between perceived and ideal frequency power laws for sediment attenuation
Authors: Collis Jon M. , Pierce Allan D. , Carey William M.
Published: September 2008

Inverse techniques based on data for long-range propagation in shallow water have recently inferred that the attenuation in certain marine sediments varies at low frequency as the 1.8 power. Idealized models predict the exponent to be exactly 2.0. The inverse inferences usually assume the bottom is a fluid, and this is ordinarily a good approximation, because the shear wave speed in bottom sediments is typically very small. Direct numerical simulation [J. M. Collis et al., Proc. Oceans 2007, Aberdeen (2007)] indicates that shear waves make a sufficient contribution to shallow water attenuation that could account for the small discrepancy in exponents. To better assess whether this is the case, the present paper analyzes the effect of shear waves on modal attenuation. The Pekeris model with a lower elastic half-space is used with the shear wave speed taken to be substantially less than the sound speed in water. The derived dispersion relation has complex roots for the horizontal wave number, and the imaginary part, found by a perturbation analysis, predicts that the shear wave contribution to the modal attenuation is proportional to the cube of the ratio of the shear wave to water sound wave speeds. [Work supported by ONR.]
Complex-density, equivalent-fluid modeling of acoustic interaction with the seafloor
Authors: Vera Michael
Published: September 2008

Acoustic interaction with the seafloor can generate both compressional and elastic shear waves in the solid. Accurate models of shear propagation are often computationally expensive and difficult to apply to long-range propagation. When the sound field in the water is of primary interest, an equivalent-fluid model of the seafloor, with parameters chosen to match the reflection coefficient of the actual elastic solid, can sufficiently characterize the effect of the bottom on energy in the water. The effective density of the seafloor material in this approach can be a complex number. Prior methods for generating equivalent fluids were intended for low shear speeds and low grazing angles. Recent developments in the technique were intended to extend its validity to higher shear speeds and a wider range of angles. These efforts were initially motivated by the need to simulate bottom-interacting arrivals for the broadband Kauai source in the North Pacific Acoustic Laboratory experiment at megameter ranges. The work to be presented involves a more detailed examination of the performance of the method, including comparisons to benchmark models and to shorter range data from this Kauai source collected as part of the Basin Acoustic Seamount Scattering Experiment.
Geoacoustic information content of bottom-moored horizontal line array data
Authors: Tollefsen Dag , Dosso Stan E.
Published: September 2008

This paper considers geoacoustic information content in matched-field inversion of acoustic data from bottom-moored horizontal line arrays. Bayesian geoacoustic inversion is applied to low-frequency multi-tone data in a synthetic shallow water environment under realistic signal-to-noise ratios and for frequency bands relevant to both controlled-source experiments and ship-noise inversion. The information content is quantified in terms of widths of marginal a posteriori probability densities of model parameters obtained by fast Gibbs sampling. The information content dependence on factors such as array length and sensor configuration, source range and bearing (from endfire to broadside), and frequency content is studied.
Bayesian geoacoustic inversion of ship-noise data from a bottom-moored horizontal line array
Authors: Tollefsen Dag , Dosso Stan E.
Published: September 2008

This paper presents results from matched-field geoacoustic inversion of low-frequency (40–150 Hz) ship-noise data recorded on a horizontal array deployed at the seafloor. Data are taken from an experiment conducted by FFI in shallow waters of the Barents Sea. Estimates of sediment parameters were obtained by inversions of narrowband data from a relatively quiet surface ship at source-array ranges of 1–6 km. The fast Gibbs sampler was used to estimate posterior probability densities of model parameters. Estimates of sound speed and density of quaternary sediment are compared with results from inversion of data from a towed source collected along the same track, and with reference values from other geophysical data collected in the area.