Trigeneration based on the pyrolysis of rural waste in India: Environmental impact, economic feasibility and business model innovation.

Pyrolysis-based waste-to-bioenergy development has the potential to resolve some of the major challenges facing rural communities in India such as poor electrification, household air pollution, and farmland degradation and contamination. Existing understanding and analysis of the economic feasibility and environmental impact of bioenergy deployment in rural areas is limited by parameter uncertainties, and relevant business model innovation following economic evaluation is even scarcer. This paper uses findings from a new field survey of 1200 rural households to estimate the economic feasibility and environmental impact of a pyrolysis-based bioenergy trigeneration development that was designed to tackle these challenges. Based on the survey results, probability distributions were constructed and used to supply input parameters for cost-benefit analysis and life cycle assessment. Monte Carlo simulation was applied to characterise the uncertainties of economic feasibility and environmental impact accounting. It was shown that the global warming potential of the development was 350 kg of CO2-eq per capita per annum. Also, the survey identified a significant mismatch between feedstock prices considered in the literature and prices asked for by the surveyed villagers. The results of the cost-benefit analysis and life cycle assessment were then applied to propose two novel business models inspired by the Business Model Canvas, which had the potential to achieve up to 90 % economic profitability and result in a benefit-cost ratio of 1.35-1.75. This is the first study achieving combined environmental and economic analysis and business model innovation for rural bioenergy production in developing countries.

Identity, storytelling and the philanthropic journey.

This article develops theoretical understanding of the involvement of wealthy entrepreneurs in socially transformative projects by offering a foundational theory of philanthropic identity narratives. We show that these narratives are structured according to the metaphorical framework of the journey, through which actors envision and make sense of personal transformation. The journey provides a valuable metaphor for conceptualizing narrative identities in entrepreneurial careers as individuals navigate different social landscapes, illuminating identities as unfolding through a process of wayfinding in response to events, transitions and turning-points. We delineate the journey from entrepreneurship to philanthropy, and propose a typology of rewards that entrepreneurs claim to derive from giving. We add to the expanding literature on narrative identities by suggesting that philanthropic identity narratives empower wealthy entrepreneurs to generate a legacy of the self that is both self- and socially oriented, these 'generativity scripts' propelling their capacity for action while ensuring the continuation of their journeys.

Nasal airway changes in bone-borne and tooth-borne rapid maxillary expansion treatments.

INTRODUCTION: Our aim was to determine the presence of a correlation between the nasal airway skeletal transverse dimension and air intake changes in rapid maxillary expansion treatments. METHODS: Sixty-one patients with maxillary transverse deficiency (11-17 years old) were randomly allocated into three groups (two treatment groups - tooth- [hyrax] or bone-borne [miniscrew-implant-based] expander - and one control group). Cone-beam computed tomography scans (CBCT) were obtained from each patient as well as acoustic rhinometry (AR) readings. Specifically, in AR, airway volume up to minimum cross-sectional areas (Vol. 1&2) and minimum cross-sectional areas (Min. 1&2) in the nasal cavity were measured. Records were obtained at two time points (initial T1 and at removal of appliance at 6 months T2). CBCTs were analyzed using AVIZO software and landmarks were placed on the nasal base. Descriptive statistics were compiled and student's t-test was used. RESULTS: Of the 480 pairings measured, only 9 showed statistically significant positive correlations between T1 and T2. Correlation data were highly variable in all categories, showing no clear tendencies. No statistical difference was found when comparing all groups in terms of airway changes. CONCLUSION: With very few positive correlations observed and otherwise highly variable data, no really conclusive finding was obtained to suggest any realistic correlation between changes in the skeletal dimensions and changes in the nasal airway.

Cranial base foramen location accuracy and reliability in cone-beam computerized tomography.

INTRODUCTION: The purpose of this study was to evaluate the reliability and accuracy in locating several different foramina in the cranial base by using cone-beam computerized tomography (CBCT) images for future use in establishing reference coordinate systems. METHODS: CBCT images from 10 dry skulls were taken with and without the foramina ovale, spinosum, and rotundum, and the hypoglossal canals filled with radiopaque gutta-percha (gold standard). Three evaluators identified the foramen landmarks in the CBCT images without gutta-percha. Mean differences and main researcher intraexaminer and interexaminer reliability were measured by using intraclass correlation coefficients for all landmark coordinates. Descriptive statistics were calculated with respect to the landmark coordinates and distances to the reference points. RESULTS: Intraexaminer and interexaminer reliability values for the x-, y-, and z-coordinates for all landmarks were greater than 0.9 with the exception of 4 (of 72) points that still had acceptable interexaminer reliability (>0.75). Mean measurement error differences obtained in the principal investigator's trials were primarily less than 0.5 mm. When comparing the mean distance differences of the same examiner and between the 3 examiners with the gold standard, the highest difference obtained was 1.3 mm. CONCLUSIONS: Foramina spinosum, ovale, and rotundum, and the hypoglossal canal all provided high intraexaminer reliability and accuracy, and can be considered acceptable landmarks to use in establishing reference coordinate systems for future 3-dimensional superimposition analysis.

Reliability of traditional cephalometric landmarks as seen in three-dimensional analysis in maxillary expansion treatments.

OBJECTIVE: To evaluate intra-examiner and inter-examiner reliability of 3D CBCT-generated landmarks previously used in traditional 2D cephalometry. MATERIALS AND METHODS: Twenty-four CBCTs NewTom 3G (Aperio Services, Verona, Italy) were randomly selected from patients participating in a clinical trial involving maxillary expansion treatments. The principal investigator located the landmarks five times, and four other investigators located the same landmarks once. Intra-examiner and inter-examiner reliability values were determined using intraclass correlation coefficients (ICCs). To assist in interpretation of the clinical significance of landmark identification differences, average mean differences for x, y, and z landmark coordinates were determined from the repeated assessments. Landmarks then were separated into groups with respect to the region they represented and then were compared via repeated measures ANOVA and multiple comparisons via Bonferroni corrected alpha. RESULTS: Intra-examiner and inter-examiner reliability for x, y, and z coordinates for all landmarks were acceptable, all being greater than 0.80. Most of the mean measurement differences obtained from trials within the principal investigator in all three axes were less than 1.5 mm. Inter-examiner mean measurement differences generally were larger than the intra-examiner differences. CONCLUSIONS: Based on this, the best landmarks for use in verifying expansion treatment results are Ekm, buccal surface, and apexes of upper molars, upper premolars and upper canines, and buccal surfaces of lower molars and lower canines. Foramen Spinosum, ELSA, Auditory External Meatus, and Dorsum Foramen Magnum demonstrated adequate reliability for determining a standardized reference system.

Rapid palatal expansion effects on nasal airway dimensions as measured by acoustic rhinometry. A systematic review.

OBJECTIVE: To evaluate available information on the effects of rapid maxillary expansion on nasal airway minimal cross-sectional area and volume, as measured by acoustic rhinometry. MATERIALS AND METHODS: An electronic database search was conducted. Based on abstracts/titles, articles were initially selected; then full articles were retrieved and were further sorted according to secondary, more stringent criteria. References from selected articles were hand-searched for potential missed publications. Clinical trials using acoustic rhinometry on subjects undergoing rapid maxillary expansion therapy were included. Syndromic or medically compromised patients and absence of an untreated control group were reasons for exclusion. Selected studies thereafter were evaluated methodologically. RESULTS: Only four articles reached final selection, and their overall methodology scores were low, limiting the applicability of results. After rapid maxillary expansion, three of four studies found statistically significant increases in minimal cross-sectional area, and two of three studies reported statistically significant increases in nasal cavity volume as compared with control groups. It appears that any increase is less stable if a traditional technique is used on patients who have passed their peak growth spurt. CONCLUSIONS: Although some increases in nasal dimensions have been reported, the changes in nasal volume were small and should not be presented to patients as a clinically significant indication for therapeutic maxillary expansion.